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  • Artikel  (593)
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  • 1
    ISSN: 1439-0361
    Schlagwort(e): mate choice ; taxonomy ; phenotypic hybrids ; fitness ; decision rule
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die als Unterarten klassifizierten europäischen Formen der Aaskrähe, Rabenkrähe und Nebelkrähe, besiedeln verschiedene, aneinandergrenzende Verbreitungsgebiete und hybridisieren in der Kontaktzone. Die Nachkommen von Mischpaaren sind fruchtbar und können sowohl mit anderen Hybriden als auch mit Raben- und Nebelkrähen erfolgreich brüten. Trotzdem kommt es zu keiner völligen Vermischung der Formen und/oder Verlagerung der Verbreitungsgebiete. Vor diesem Hintergrund untersuchten wir die Partnerwahl von Aaskrähen in der Hybridisierungszone auf der nordfriesischen Insel Amrum und stellten fest, daß Partner gleichen Phänotyps häufiger miteinander verpaart waren, als stochastisch zu erwarten gewesen wäre. Unsere Daten bestätigen vergleichbare Studien aus Hybridisierungszonen in Italien und Sibirien. Wir schließen daraus, daß phänotypisch selektive Partnerwahl bei der Aaskrähe ein allgemeines Phänomen sein könnte und diskutieren, warum dieses Verhalten anfitness-relevante Parameter gekoppelt sein sollte. Um welche es sich dabei handeln könnte, wurde bisher nicht hinreichend untersucht und muß deshalb offen bleiben.
    Notizen: Summary Carrion Crow and Hooded Crow are regarded as subspecies of the Crow. They show frequent hybridisation along the adjacent borders of their distribution. Mixed pairs produce fertile offspring which are able to breed successfully with both hybrids and mates of either phenotype. However, hybridisation does not lead to phenotypic changes of Carrion and Hooded Crows in general nor in their distinct distribution. We studied the mating behaviour of Crows in the hybrid zone on the Island of Amrum (Schleswig-Holstein, Germany) and found evidence that Crows may prefer mates of the same phenotype. Our data confirm previous studies which reported assortative mating with respect to plumage coloration from hybrid zones in Italy and Siberia. We discuss why this behaviour should be related tofitness traits which in our opinion have not yet been studied adequately nor identified.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Journal of heuristics 5 (1999), S. 145-158 
    ISSN: 1572-9397
    Schlagwort(e): evolutionary algorithms ; genetic algorithms ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Abstract This paper shows how evolutionary algorithms can be described in a concise, yet comprehensive and accurate way. A classification scheme is introduced and presented in a tabular form called TEA (Table of Evolutionary Algorithms). It distinguishes between different classes of evolutionary algorithms (e.g., genetic algorithms, ant systems) by enumerating the fundamental ingredients of each of these algorithms. At the end, possible uses of the TEA are illustrated on classical evolutionary algorithms.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 2 (1968), S. 296-298 
    ISSN: 1432-0827
    Schlagwort(e): Calcium ; Lipid ; Bacteria ; Calcification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé On a fait ce travail pour determiner si le facteur responsable pour la liaison de calcium par un calcifableBacterionema matruchotii est dans la fraction lipide de la cellule. Des cellules congelees et sechees ont ete extraites par le chloroform-methanol. La fraction de chloroform-methanol, les cellules extraites et les cellules non traitees ont ete examinees pour la liaison de calcium. La fraction du chloroform-methanol et les cellules non traitees avaient la liaison de calcium. Les cellules extraites n'en avaient pas.
    Kurzfassung: Zusammenfassung Diese Arbeit wurde durchgeführt um festzustellen, ob sich der Faktor für die Calcium-bindung, durch das calcifizierendeBacterionema matruchotii, in der Lipoidfraktion befindet. Die lyophiilisierten Zellen wurden mit Chloroform-Methanol extrahiert. Die Chloroform-Methanol-Fraktion, die extrahierten Zellen, sowie die nicht behandelten Zellen wurden auf eine Calciumbindung hin untersucht. Die Chloroform-Methanol-Fraktion und die nicht behandelten Zellen demonstrierten eine Calciumbindung. Die extrahierten Zellen hingegen nicht.
    Notizen: Abstract This work was done to determine whether the factor responsible for calcium binding by a calcifiableBacterionema matruchotii is in the lipid fraction of the cell. Freeze-dried cells were extracted with chloroform-methanol. The chloroform-methanol fraction, the extracted cells and untreated cells were examined for calcium binding. The chloroform-methanol fraction and the untreated cells bound calcium. The extracted cells did not.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 4 (1969), S. 260-268 
    ISSN: 1432-0827
    Schlagwort(e): Cartilage ; Histochemistry ; Staining ; Protein ; Polysaccharide ; Calcification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Des coupes de cartilage épiphysaire frais de jeunes rats, effectuées à la main, sont colorées à pH=4,5 dans des solutions à 0,01% de divers colorants cationiques, appartenant aux groupes de la thiazine, oxazine, azine, triphénylméthane, acridine, et phthallocyanine. Les granules intracellulaires métachromatiques, mises en évidence antérieurement par le bleu de toluidine, sont également identifiées à l'aide de l'azur A, le bleu de méthylène et le bleu de crésyl. Les granules se colorent moins bien à la thionine, le rouge neutre, la safranine O, le bleu de toluylène et l'acridine orange. Dans les conditions utilisées, la matrice de la zone de réserve et la matrice de la zone hypertrophique inférieure (en voie de calcification) se colorent, alors que les matrices des zones prolifératives et hypertrophiques supérieures ne prennent pas les colorants. La gallocyanine, le violet cristal, la fuchsine basique, l'azocarmin B, le bleu de gallamine et la bleu alcian ne se colorent pas ou donnent des réactions colorées différentes de celles décrites ci-dessus. Il semble que le pK et le poids moléculaire des colorants jouent un rôle important, mais ils ne paraissent pas être les seuls facteurs intervenant dans la coloration des granules. Un changement, lié à la calcification, semble intervenir au niveau du matériel métachromatique (probablement des polysaccharides protéiques), aussi bien dans la matrice que les cellules cartilagineuses épiphysaires.
    Kurzfassung: Zusammenfassung Handpräparierte Schnitte von frischem Epiphysenknorpel junger Ratten wurden bei einem pH von 4,5 in 0,01% igen Lösungen verschiedener kationischer Farbstoffe folgender Klassen gefärbt: Thiazin, Oxazin, Azin, Triphenylmethan, Acridin und Phthalocyanin. Die intracellulären β-und γ-metachromatischen Granula, erstmals mit Toluidinblau im frischen Gewebe nachgewiesen, konnten auch gut mit Azur A, Methylenblau und Brillantkresylblau dargestellt werden. Die Granula konnten ebenfalls, aber weniger gut, mit Thionin, Neutralrot, Safranin D, Toluylenblau und Acridinorange gefärbt werden. Unter diesen Färbungsbedingungen werden die inaktive Matrixzone und die untere hypertrophische (verkalkende) Matrixzone angefärbt, während die proliferative und die obere hypertrophische Matrixzone sich nicht färben. Gallocyanin, Kristallviolett, basisches Fuchsin, Azokarmin B, Gallaminblau und Alzianblau färbten entweder gar nicht, oder gaben ein anderes als das obenbeschriebene Färbemuster. Es wird vorgeschlagen, daß das pK und das Molekulargewicht der Farbstoffe wichtig aber nicht unbedingt die einzigen Faktoren sind, die die Färbung der Granula bestimmen. Die Resultate zeigen, daß eine Veränderung im metachromatischen Material (vermutlich Proteinpolysaccharide) vorliegt, und zwar sowohl in der Matrix als in den Zellen des Epiphysenknorpels; diese Veränderung scheint im Zusammenhang mit der Verkalkung zu stehen.
    Notizen: Abstract Hand-cut sections of fresh epiphyseal cartilage from young rats were stained at pH 4.5 in 0.01% solutions of various cationic dyes of the thiazine, oxazine, azine, triphenylmethane, acridine, and phthallocyanin classes. The intracellular β-and γ-metachromatic granules, previously demonstrated in fresh tissues with toluidine blue, were also demonstrated well with azure A, methylene blue, and brilliant cresyl blue. The granules were also demonstrated, but not as well, by thionin, neutral red, safranin O, toluylene blue, and acridine orange. Under the conditions of staining, the reserve zone matrix and the lower hypertrophic (calcifying) zone matrix stained, whereas the proliferative and upper hypertrophic zone matrix did not stain. Gallocyanin, crystal violet, basic fuchsin, azocarmine B, gallamine blue, and alcian blue either did not stain, or gave a different pattern of staining from that described above. It is suggested that the pK and molecular weight of the dyes are important, but not necessarily the only factors in determining the staining of the granules. The results indicate that there is a change in the metachromatic material (presumably proteinpolysaccharide) in both the matrix and cells of epiphyseal cartilage, which appears to be related to calcification.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 4 (1969), S. 20-38 
    ISSN: 1432-0827
    Schlagwort(e): Calcification ; Epiphyseal Cartilage ; Bone ; Electrolytes ; Organic matrices
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Un procédé de dissection a été mis au point pour permettre l'analyse zonale du cartilage de l'épiphyse des os de la jambe d'un foetus bovin. Des échantillons de tissu complet et lavé venant des différentes zones ont été analysés pour déterminer leur contenu en électrolyte et en constituants organiques, ainsi que pour leur densité, cendres et humidité. Les résultats ont montré que lorsque la quantité de cendres et la densité augmentaient, l'eau contenu dans le tissu diminuait. Les quantités de cendres dans les zones de cartilage en voie de calcification étaient plus grandes qu'il avait été. Quand elles étaient exprimées comme un pourcentage du poids sec, elles étaient les plus importantes dans le cartilage lavé calcifié que dans le autre zones. Au début de la minéralisation du cartilage, la quantité de Na (m moles/l de tissu frais) diminuait tandis que celles du Ca et du P inorganique augmentaient. Les niveaux de Mg augmentaient pendant que la calcification se poursuivait, mais seulement à une faction du taux du Ca et du P. Les rapports Ca/P inorganique étaient les plus grands dans le cartilage au repos (Cartilage non-différentié hyalin), suggérant un lien initiale entre Ca et les chrondromucoprotéines. Cependant, au début de la calcification, pendant la prolifération du cartilage les rapports Ca/P étaient beaucoup plus petits (ca. 1.50) mais augmentaient graduellement avec l'advancement de la minéralisation. Des changements importants survenaient dans la composition de la phase organique, pendant la calcification endochondrale. Comme il a été déterminé par l'analyse de l'hydroxyproline la quantité de collagéne diminuait progressivement pendant la calcification du cartilage, mais augmentait rapidement pendant la formation d'os. Comme il a été déterminé par l'analyse de l'héxosamine et du sulfute les chrondromucoprotéines étaient aux niveaux les plus éléves pendant la prolifération du cartilage et diminuaient constamment au cours de la calcification. Cependant, bien que la calcification était déja très avancée dans le cartilage hypertrophique, de grandes quantites de mucopolysaccharides étaient encore présentes. Les rapports sulfure/hhéxosamine montraient un léger déclin pendant les premiéres étapes de la calcification, mais augmentaient beaucoup pendant le cours de la minéralisation. Les quantités d'acide sialique étaient plus grandes dans le cartilage de l'épiphyse que dans le cartilage au repos ou dans l'os. Les lipides augmentaient rapidement pendant la calcification du cartilage, mais étaient très réduites dans l'os complètement formé. La signification de ces résultats est discutée.
    Kurzfassung: Zusammenfassung Eine Seziermethode, die eine Schichten-Analyse der Beinepiphysenplatte von Rinderfeten erlaubt, wurde entwickelt. Proben vor und nach Waschen des Gewebes der verschiedenen Schichten werden untersucht in bezug auf Elektrolyte und organische Bestandteile, als auch in bezug auf Dichte, Aschengehalt und Feuchtigkeit. Die Resultate zeigten eine Zunahme des Aschengehaltes und der Dichte, während der Wassergehalt abnahm. Unerwartet hoch waren die Aschenwerte im in Verkalkung begriffenen Knorpel. Ausgedrückt in Prozent Trockengewicht, ergab gewaschener, verkalkter Knorpel den höchsten Wert aller Zonen. In den Frühstadien der Knorpelmineralisation nahm der Natriumgehalt (m Mol/l Frischgewebe) ab, während Ca und anorganischer P zunahmen. Mit fortschreitender Verkalkung erhöhte sich auch der Magnesium-Spiegel, allerdings nur zu einem Bruchteil des Ausmaßes, in welchem Ca und P zunahmen. Die höchsten Ca/P anorg. Verhältnisse wurden im Ruheknorpel (undifferenzierter hyaliner Knorpel) gefunden, was auf eine initiale Bindung von Ca durch Chondromucoproteine hinweist. Die Ca/P-Verhältnisse proliferierenden Knorpels waren jedoch bei Verkalkungsbeginn viel tiefer (ca. 1.50). Diese nahmen allerdings mit fortschreitender Mineralisierung stetig zu. In der endochondralen Verkalkungsphase fanden markante Veränderungen in der Zusammensetzung des organischen Anteils statt. Basierend auf der Hydroxyprolinanalyse nahm der Collagengehalt in der knorpeligen Verkalkungsperiode fortschreitend ab, während er jedoch bei der Knochenbildung rasch zunahm. Die an Hand von Hexosamin- und Schwefelanalysen bestimmten Chondromucoproteingehalte ergaben Höchstwerte im proliferierenden Knorpel und fielen stetig ab mit zunehmender Verkalkung. Trotz der im hypertrophischen Knorpel schon weit fortgeschrittenen Verkalkung waren immer noch große Mengen an Mucopolysacchariden vorhanden. Die Schwefel/Hexosamin-Verhältnisse zeigten eine minimale Abnahme in den frühen Verkalkungsphasen, nahmen jedoch markant zu bei fortschreitender Mineralisation. Der Sialinsäurespiegel war im Epiphysenknorpel, verglichen mit demjenigen des Ruheknorpels oder Knochens, erhöht. In der knorpeligen Verkalkungsphase nahmen die Lipide rasch zu, während jedoch die Werte des vollständig ausgebildeten Knochens stark vermindert waren. Die Bedeutung dieser Ergebnisse wird besprochen.
    Notizen: Abstract A dissection procedure has been devised to permit zonal analysis of the epiphyseal plate of fetal calf leg bones. Samples of whole and washed tissue from the various zones were analyzed for their content of electrolyte and organic constituents, as well as for density, ash and moisture. Results showed that as ash content and density increased, water content decreased. Ash levels in calcifying cartilage zones were unexpectedly high. When expressed as a percentage of dry weight, washed calcified cartilage had the highest content of any zone. In the early stages of the mineralization of cartilage, Na content (mmoles/l of fresh tissue) decreased as Ca and inorganic P increased. Magnesium levels increased as calcification proceeded, but only at a fraction of the rate of Ca and P. Ratios of Ca/inorganic P were highest in resting cartilage (non-differentiated hyaline cartilage), suggesting an initial binding of Ca to chondromucoproteins. However, at the onset of calcification in proliferating cartilage, Ca/P ratios were much lower (ca. 1.50), but gradually increased with advancing mineralization. Marked changes occurred in the composition of the organic phase during endochondral calcification. As determined by hydroxyproline analysis, collagen content progressively decreased during cartilaginous calcification, but increased rapidly during bone formation. As determined by hexosamine and sulfur analysis, chondromucoproteins were at highest levels in proliferating cartilage and decreased steadily as calcification increased. However, although calcification was already well advanced in hypertrophic cartilage, large amounts of mucopolysaccharide still were present. Sulfur/hexosamine ratios showed a slight decline during the early stages of calcification, but increased markedly with further mineralization. Sialic acid levels were elevated in epiphyseal cartilage over those in resting cartilage or bone. Lipids increased rapidly during cartilaginous calcification, but were greatly reduced in fully-formed bone. The significance of these findings is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Coral reefs 17 (1998), S. 37-47 
    ISSN: 1432-0975
    Schlagwort(e): Key words Coral ; Calcification ; Biomineralisation ; Autoradiography ; Freeze-substitution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract  The uptake of 45Ca and/or 14C by the skeleton of coral colonies has been commonly used to investigate the processes of calcification. This study reports the differential uptake of these tracers within different regions of the skeleton and tissues of individual corallites and polyps of the hermatypic coral Galaxea fascicularis. Incubation in 45Ca in the light resulted in 80 percent of the 45Ca taken up being deposited in the skeleton. Autoradiography of transverse and longitudinal slices of freeze-substituted polyps and corallites showed that in the light 45Ca was incorporated into the exsert septa, the outside of the thecal walls of the corallite and the inner edges of the septa. Incorporation did not occur in the costae. The radioactivity in the skeleton was considerably greater than in the tissues. In the dark, or in the presence of the photosynthetic inhibitor Diuron, 45Ca was taken up by the exsert septa and was patchily distributed in the corallite walls which suggests that it was not a result of isotopic exchange. The differential incorporation of 45Ca onto the exsert septa was confirmed by scintillation counting. Negligible radioactivity remained in the extrathecal coelenteron after a brief 5 min rinse in non-radioactive seawater. Only 0.1% of 14C taken up in the light was incorporated into the skeleton and this was confirmed by autoradiography. In the presence of Diuron or in the dark, very little 14C was incorporated into tissues or skeleton and in autoradiographs was either not evident in the skeleton or the distribution was similar to that seen in autoradiographs of 45Ca uptake. These results show that the deposition of 45Ca, and therefore calcium carbonate, occurs at specific loci on the skeleton of a corallite. In the dark, deposition occurs specifically at the growing points of the corallite. Differential deposition of calcium carbonate within individual corallites has not been previously reported.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    ISSN: 1573-0832
    Schlagwort(e): Africa ; Fusarium ; F. moniliforme ; grain ; Lesotho ; mating population ; Nigeria ; taxonomy ; Zimbabwe
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Several Fusarium species have been found associated with millet and sorghum in Nigeria, Lesotho and Zimbabwe. Amongst these, some isolates were originally identified as short- and long-chained types of F. nygamai. However, there was some question as to the correct identification of the long chained types. This study reclassified some of the isolates with long microconidial chains as F. moniliforme. Morphologically, these strains do not produce chlamydospores like F. nygamai, but produce swollen hyphal cells or resistant hyphae. The isolates in this study were crossed with the mating-type tester strains of Gibberella fujikuroi (F. moniliforme and G. nygamai (F. nygamai). Of the isolates with long chains of microconidia and other characteristics of F. moniliforme, 36% crossed with mating population ''A'' of G. fujikuroi. Of the isolates with characteristics of F. nygamai, 65% crossed with the testers used to produce the teleomorph of F. nygamai. Mating tests support the separation of the sample population into F. moniliforme and F. nygamai. The results of this study show that genetics can be an aid in resolving some problems in fungal taxonomy.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Antonie van Leeuwenhoek 71 (1997), S. 375-378 
    ISSN: 1572-9699
    Schlagwort(e): Candida novakii ; taxonomy ; yeasts
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two strains of an undescribed species of the genus Candida were isolated from decaying wood of Quercus sp. A description of the new species Candida novakii is given.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Antonie van Leeuwenhoek 72 (1997), S. 29-38 
    ISSN: 1572-9699
    Schlagwort(e): phylogeny ; prosthecobacter ; taxonomy ; Verrucomicrobia ; Verrucomicrobiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Four strains of nonmotile, prosthecate bacteria were isolated in the 1970s and assigned to the genus Prosthecobacter. These strains were compared genotypically by DNA/DNA reassociation and 16S rDNA based phylogenetic analyses. Genotypic comparisons were complemented with phenotypic characterizations. Together, these studies clearly indicate each Prosthecobacter strain represents a novel species of bacteria. We propose three new species of Prosthecobacter, P. dejongeii strain FC1, P. vanneervenii strain FC2, and P. debontii strain FC3; P. fusiformis is reserved for the type strain of the genus, strain FC4. Additionally, we propose the genera Prosthecobacter and Verrucomicrobium, currently members of the order Verrucomicrobiales, to comprise a novel higher order taxonomic group, the division Verrucomicrobia div. nov. and the class Verrumicrobiae class nov. Many novel members of the Verrucomicrobia, as revealed by molecular ecology studies, await isolation and description.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Antonie van Leeuwenhoek 72 (1997), S. 149-158 
    ISSN: 1572-9699
    Schlagwort(e): keratinophilic fungi ; Neoarachnotheca ; Neoarachnotheca keratinophila ; Nannizziopsis tropicalis ; Onygenales ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Neoarachnotheca is proposed as a new genus of Onygenales. The outstanding generic characteristics are white, spherical ascomata with a wall formed by a network of hyphae and spherical, subhyaline ascospores with an irregular sheath. Nt. keratinophila, the type species, characterized by wavy peridial hyphae has been isolated from marine and river sediments and Myriodontium keratinophilum is its anamorph. Nannizziopsis tropicalis is proposed as a new species based on a strain isolated from soil in Burundi. RFLPs analysis of ITS and 5.8S rDNA support these proposals. The differences with related genera are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Antonie van Leeuwenhoek 74 (1998), S. 229-235 
    ISSN: 1572-9699
    Schlagwort(e): Dipodascus capitatus ; D.spicifer ; Geotrichum clavatum ; yeast ; taxonomy ; DNA heterogeneity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The G+C contents of 25 strains of Dipodascus capitatus, Dipodascus spicifer and Geotrichum clavatum were found to be heterogeneous on basis of derivative graphs of the melting profiles. Strains showing similar derivative graphs of the melting curve exhibited high levels of DNA homology (80-100%); strains showing dissimilar derivative graphs exhibited low levels of DNA homology (5 to 45%). Being considered separate taxa on basis of these parameters, D. capitatus, D. spicifer and G. clavatum could be identified by a combination of the key characteristics growth on xylose, cellobiose, salicin and arbutin.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Plant molecular biology reporter 16 (1998), S. 147-155 
    ISSN: 1572-9818
    Schlagwort(e): allele-specific PCR ; Beta ; ITS1 ; plant identification ; rDNA ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sequence variation in the ITS1 locus of the nuclear ribosomal DNA in beets has previously been used to reconstruct phylogeny of the species in the genus Beta. We have developed protocols that allow the identification of Beta taxa by use of taxon-specific primers. Beta sections, species and subspecies can be identified. Differences within the ITS1 region of a single base can be exploited for species identification. The results from this study not only provide effective methods for wild beet identification, but also indicate the potential use of the techniques in other crops.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Journal of insect conservation 2 (1998), S. 151-159 
    ISSN: 1572-9753
    Schlagwort(e): Orthoptera ; biodiversity ; taxonomy ; conservation.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Wissenschaftskunde und Wissenschaftsorganisation, Hochschul- und Universitätswesen, Museumswissenschaft
    Notizen: Abstract It is estimated that only 10–15% of the world's insect fauna has been described and named. Efforts to inventory insect biodiversity are hampered by this taxonomic impediment, which is compounded by the logistical problems of an insufficient taxonomic workforce and their remote location in museums thousands of miles from the areas of highest biodiversity. Compared to most other invertebrate groups however, the taxonomic impediment is relatively benign in the order Orthoptera. This is a small to medium-sized order (approximately 20 000 described species) which is well known taxonomically, owing to the group's agricultural importance worldwide. Furthermore, orthopteran taxonomists are now fortunate to have a published up-to-date catalogue of all known species, which has just become accessible as a regularly updated database on the World Wide Web. Whilst new information technology, in the form of e-mail networks, World Wide Web sites and CD-ROM information archives, is already enhancing communication between specialists and helping to reduce the logistical problems of documenting orthopteran biodiversity, a major reinvestment in basic taxonomic research is needed if we are to reduce the existing taxonomic impediment significantly. There is general agreement that an internationally coordinated approach will be necessary and priorities must be set to tackle the biodiversity/systematics crisis. In the future, the Orthoptera can make an important contribution to invertebrate faunal surveys and have potential as an indicator taxon. Furthermore, the Orthoptera Species File establishes a taxonomic framework which could be readily enlarged to include geographic data and phenology of species from existing museum specimens.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 14
    ISSN: 1572-9745
    Schlagwort(e): Biological control ; insects ; pathogens ; germination ; taxonomy ; genetic variability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Pigweeds (Amaranthus spp.) are of economic importance worldwide. In Europe, Amaranthus retroflexus is one of the ten weed species of greatest economic importance. It is a serious problem weed in several field crops (e.g. maize), as well as in vegetables, orchards and grape vines. It is an annual spreading by seeds which have a long viabilityand are dispersed principally by wind and water, but also by machinery. There is great variability in seed germination which renders control with post-emergence herbicides difficult. In addition, triazine herbicide-resistant populations occur in ten European countries. The aim of this subproject of COST action 816 is to investigate the possibilities of classical and inundative biological control of Amaranthus spp., to characterize potentialbiological control agents and to develop methods for their integration with current phytosanitary measures in the target crops. The project was initiated with an extended literaturesurvey followed by field surveys for insects and pathogens associated with Amaranthus spp. in several European countries. Promising isolates of fungal pathogens have been tested ondetached leaves and whole plants, and initial studies on the application of pathogens causing damping off in seedlings have been made. Further, the variability of different provenances ofAmaranthus spp. in response to fungal attack has been investigated
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 15
    Digitale Medien
    Digitale Medien
    Springer
    Journal of the history of biology 32 (1999), S. 509-555 
    ISSN: 1573-0387
    Schlagwort(e): Louis Agassiz ; Spencer Baird ; Charles Girard ; reputation ; taxonomy ; ichthyology ; Museum of Comparative Zoology ; Smithsonian Institution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geschichte
    Notizen: Abstract The reputations of scientists among their contemporaries depend not only on accomplishment, but also on interactions affected by influence and personality. The historical lore of most fields of scientific endeavor preserve these reputations, often through the identification of founders, innovators, and prolific workers whose contributions are considered fundamental to progress in the field. Historians frequently rely on the historical lore of scientists to guide their studies of the development of ideas, exhibiting justifiable caution in reassessing reputations in the light of current knowledge. However, the transmission of historical lore can obscure the relative importance of accomplishment, influence and personality in shaping contemporary reputations, leaving the historian to either accept reputations at face value or attempt to reconstruct the context in which they were created. The science of taxonomy, because of its rules of priority, leaves a relatively accurate record of historical accomplishment through the persistence of taxa in catalogues and faunal guides. These records allow the modern historian an unbiased means to assess the relative accomplishments of historical figures and therefore a means to critically reassess reputations independent of personality and influence. In the historical lore of North American ichthyology, Louis Agassiz at Harvard and Spencer Baird at the Smithsonian emerge as central figures in the early development of the field during the mid-1800s, contributing not only through the quality and quantity of their science, but also through their roles as institutional leaders and mentors to workers who followed. Charles Girard, originally a student of Agassiz's and later a coworker with Baird, receives little notice in the history of ichthyology, and his reputation is that of a minor player in the initial description of the North American fish fauna, and one whose work appears to have been flawed or even careless when compared to his contemporaries. However, a review of both contemporary and modern taxonomic works reveals that Girard's productivity far exceeded that of either Agassiz or Baird. Furthermore, an examination of the tendency of Girard and his contemporaries to introduce synonymous names into the literature, which might reflect careless or uncritical work, suggests that Girard was among the more accomplished workers of hisera, including Agassiz and Baird. Girard's low ranking in the folklore of North American ichthyology, therefore, can not be attributed to discernible shortcomings in his scientific work, but rather to a public and private campaign of criticism waged by Agassiz after Girard's departure from Harvard. While Agassiz's dispute with Girard stemmed from their personal interactions, he expressed them as criticisms of Girard's work, and thus helped shape Girard's scientific reputation as it has been transmitted through the lore of ichthyology. This case study reveals how scientific reputation may not always rest on accomplishment, but can be influenced by personal interactions obscured by time but nonetheless important to history.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 3 (1969), S. 151-162 
    ISSN: 1432-0827
    Schlagwort(e): Calcification ; Physiologic ; Phosphonic Acids ; Phosphates ; Crystallization ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé On a étudié la formation de l'hydroxyapatite de calcium cristallin à partir de solutions d'ions de calcium et de phosphate et l'inhibition de la croissance de cristaux de l'hydroxyapatite de calcium au moyen de polyphosphonates et de polyphosphates. Les polyphosphonates, éthane hydroxy-1-diphosphonate-1,1 de disodium et dichlorométhanediphosphonate de disodium, sont inhibiteurs efficaces contre la croissance de cristaux de l'hydroxyapatite de calcium. Les polyphosphates sont aussi inhibiteurs efficaces contre la croissance de cristaux de l'hydroxyapatite de calcium tant que le niveau exigé de polyphosphate intact est présent dans le système. Cependant, à cause de leur instabilité hydrolytique, qui est soulignée par une température élevée, valeur de pH basse, et certaines enzymes, la concentration du polyphosphate diminue avec le tempsin vitro, et son activité comme inhibiteur est perdue. Au contraire aux polyphosphates, les polyphosphonates sont hydrolytiquement stables. Les polyphosphonates sont chimiosorbés sur la surface des microcristallites de l'hydroxyapatite de calcium, ainsi empêchant l'occurrence d'autre croissance de cristaux semblable à l'action d'autres poisons connus de croissance de cristaux. On propose l'extension de cette action sur la formation de l'apatite et cette stabilité des polyphosphonates aux applications médicales et dentaires concernant le metabolisme pathologique de calcium et de phosphate.
    Kurzfassung: Zusammenfassung Die Bildung des kristallinen Calciumhydroxyapatit aus Lösungen, welche Calcium- und Phosphationen enthalten, und die Hemmung der Bildung von kristallinen Calciumhydroxyapatit durch Polyphosphonate und Polyphosphate wurden untersucht. Polyphosphonate, Dinatriumäthan-1-hydroxyl-1,1-diphosphonat und Dinatriumdichloromethandiphosphonate verhindern das Kristallwachstum des Calciumhydroxyapatits. Die Polyphosphate verhindern ebenfalls das Kristallwachstum des Calciumhydroxyapatits, solange die notwendige Konzentration des nicht hydrolysierten Polyphosphats vorhanden ist. Wegen ihrer hydrolytischen Unbeständigkeit, die durch hohe Temperatur, niedrige pH und bestimmte Enzyme erhöht wird, vermindert sich jedoch die Konzentration des Polyphosphats allmählichin vitro, und ihre Hemmungsaktivität geht verloren. Im Gegensatz zu den Polyphosphaten sind die Polyphosphonate hydrolytisch beständig. Die Polyphosphonate werden an der Oberfläche der Mikrokristallite des Calciumhydroxyapatits chemisorbiert und verhindern, wie andere bekannte Kristallwachstumsgifte, auf diese Weise weiteres Kristallwachstum. Die Beständigkeit der Polyphosphonate und ihre Chemisorption an dem Apatit empfehlen ihren Gebrauch in der ärztlichen und zahnärztlichen Praxis, soweit sie den pathologischen Calcium- und Phosphatstoffwechsel betreffen.
    Notizen: Abstract The formation of crystalline calcium hydroxyapatite from solutions of calcium and phosphate ions and the inhibition of calcium hydroxyapatite crystal growth by polyphosphonates and polyphosphates have been studied. The polyphosphonates, disodium ethane-1-hydroxy-1,1-diphosphonate and disodium dichloromethane diphosphonate, are effective inhibitors of calcium hydroxyapatite crystal growth. The polyphosphates are also effective inhibitors of calcium hydroxyapatite crystal growth as long as the required level of intact polyphosphate is present in the system. However, because of their hydrolytic instability, which is enhanced by high temperature, low pH, and certain enzymes, the concentration of the polyphosphate decreases with timein vitro, and its activity as an inhibitor is lost. In contrast to the polyphosphates, the polyphosphonates are hydrolytically stable. The polyphosphonates are chemisorbed on the surface of the microcrystallites of calcium hydroxyapatite and, in the manner of other known crystal growth poisons, thus prevent further crystal growth. The stability of the polyphosphonates and their chemisorption on apatite suggest their use in medical and dental applications involving pathological calcium and phosphate metabolism.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 3 (1969), S. 184-193 
    ISSN: 1432-0827
    Schlagwort(e): Mitochondria ; Calcification ; Calcium ; Chondrocytes ; Growth plate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Des cultures d'épiphyse prélevées sur des rats et des souris ont été étudiées sous le microscope électronique. Un profile de granules mitochondriques de densité électronique a été trouvé. Les chondrocytes dans la zone proliférative avaint peu de granules, alors que ceux des zones successives ont montré une augmentation progressive de leur nombre et densité jusqu'à ce que la zone de calcification provisoire ait été atteinte. Cette zone a montré une distribution périphérique de mitochondries et une réduction du nombre et de la densité des granules mitochondriques. Du calcium isotopique 47 a été utilisé autoradiographiquement pour déterminer la location de calcium dans ces cellules. Des grains ont été trouvés sur les membranes R.E. et sur la plupart des mitochondries. La preuve d'un profile de ces granules et de leur rapport spatial avec la face de minéralisation indique une action éventuelle de mitochondries dès le début de la calcification de la matrice.
    Kurzfassung: Zusammenfassung Epiphysekulturen von Ratten und Mäusen wurden unter dem Elektronenmikroskop untersucht. Ein Profil von mitochondrischen Körnchen mit elektronischer Dichte wurde gefunden. Chondrozyten in der Proliferationszone wiesen wenig Körnchen auf, während die der nachfolgenden Zonen allmählich an Zahl und Dichte zunahmen, bis die Zone der provisorischen Verkalkung erreicht wurde. Diese Zone zeigte eine periphere Verteilung der Mitochondrien und eine Abnahme in Zahl und Dichte der mitochondrischen Körnchen. Isotopes Kalzium 47 wurde autoradiographisch verwendet, um die Lage des Kalziums in diesen Zellen zu bestimmen. Körnchen wurden auf den E.R.-Membranen und auf einem Großteil der Mitochondrien gefunden. Der Nachweis eines Profils dieser Körnchen und ihres räumlichen Verhältnisses zur Mineralisierungsfläche weist auf einen möglich Einfluß der Mitochondrien mit Beginn der Matrixverkalkung hin.
    Notizen: Abstract Rat and mice epiphyseal growth plates were studied with the electron microscope. A gradient of mitochondrial electron-dense granules was found. Chondrocytes in the proliferative zone had few granules, while those of the succeeding zones showed a gradual increase in number and density until the zone of provisional calcification was reached. This zone showed a peripheral distribution of mitochondria and a decrease in the number and density of mitochondrial granules. Isotopic47calcium was used autoradiographically to determine the location of calcium in these cells. Grains were found over the endoplasmic reticulum membranes and over most mitochondria. The demonstration of a gradient of these granules and their spatial relation to the mineralization front suggests a possible involvement of mitochondria in the onset of matrix calcification.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 4 (1969), S. 78-83 
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Calcification ; Osteomalacia ; Phosphorus ; Vitamin D
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Les effects d'une dose de 1 mg de vitamine D3 (40 000 Unités,) administrée par voie intra-veineuse, ont été étudiés sur l'histologie osseuse et le métabolisme du phosphore chez 19 sujets contrôles dont l'histologie était normale et 28 malades présentant les caractères histologiques de l'ostéomalacie par carence vitaminique D. L'administration de la vitamine D n'a entraîné aucune modification histologique ou biologique significative chez les sujets contrôles. Mais chez les ostéomalaciques, il est apparu en moins de sept jours une augmentation très significative du front de calcification à l'interface tissue-ostéoïde-tissue-calcifié. Cette modification s'accompagnait d'une ascension progressive de la phosphatémie et de la réabsorption tubulaire du phosphore atteignant dans le même délai des valeurs normales.
    Kurzfassung: Zusammenfassung Bei 19 Patienten mit normaler Knochenhistologie und bei 28 Patienten mit histologisch gesicherter Osteomalacie wurde die Wirkung von 1 mg Vitamin D3 (40000 Iv) i.v. auf die Knochenhistologie und den Phosphatmetabolismus untersucht. Bei den Kontrollpatienten konnten keine signifikanten Änderungen nach Vitamin D festgestellt werden, wogegen die Osteomalacie-patienten innerhalb von 7 Tagen eine deutliche Zunahme der Verkalkungszone an der Grenze zwischen Osteoid- und Knochengewebe zeigten. Diese Änderung war von einer fortschreitenden Zunahme des Serum-Phosphates, verbunden mit einer gesteigerten renalen tubulären Rückabsorption des Phosphates begleitet; beide kehrten anschließend gleichzeitig wieder zur Norm zurück.
    Notizen: Abstract The effect of a 1 mg dose of intravenous Vitamin D3 (40,000 i.u.) on bone histology and phosphate metabolism was investigated in 19 patients with normal bone histology and 28 patients with histological evidence of osteomalacia. No significant changes occurred in the control patients after Vitamin D but the patients with osteomalacia showed a marked increase, within seven days, in the proportion of osteoid having a calcification front. This was accompanied by a progressive rise in the serum phosphate, which was associated with an increase in the renal tubular reabsorption of phosphate to normal.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 19
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 4 (1969), S. 231-244 
    ISSN: 1432-0827
    Schlagwort(e): Calcification ; Pyrophosphate ; Inhibitors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Les propriétés d'induction de calcification des liquides biologiques peuvent être mesurées, in vitro et in vivo, par leur possibilité de redurcir des blocs d'émail décalcifié. Cette propriété est exprimée par les concentrations de calcium (et de phosphate) de solutions synthétiques inductrices de calcification, de concentrations et d'activité connues. Un plasma humain typique a une activité inductrice correspondant à celle d'une solution contenant du calcium, 0,70 mM, Ca/P, 1,67 et fluorure, 0,05 mM. L'activité relativement peu élevée des sérums et des plasmas s'explique par la présence d'inhibiteurs ioniques. L'ion phosphate est l'un d'eux, mais ne peut rendre compte de l'inhibition totale. Des anions et des cations sont responsables de l'inhibition, avec un rôle majeur pour les cations. Les ions suivants, en concentration physiologique, jouent un rôle inhibiteur: P7O 7 4− , HCO 3 − , SiO 4 2− , CrO 4 2− , Mg2+, Zn2+. Un mélange de ces ions provoque une inhibition totale identique à celle du plasma.
    Kurzfassung: Zusammenfassung Der Einfluß biologischer Flüssigkeiten auf den Verkalkungsvorgang kann in vitro und in vivo anhand ihrer Fähigkeit, enthärtete Blöcke von Zahnschmelz wieder zu härten, gemessen werden. Diese Aktivität wird ausgedrückt als Konzentration des Calciums (und Phosphates) synthetischer calcifizierender Lösungen mit bekannter Konzentration und Aktivität. Die Aktivität eines charakteristischen menschlichen Plasmas entsprach derjenigen einer Lösung folgender Zusammensetzung: Calcium 0,70 mM; Ca/P=1,67 und Fluorid 0,05 mM. Die relativ niedrige Aktivität von Serum und Plasma ist bedingt durch das Vorhandensein einer Anzahl ionischer Inhibitoren. Das Pyrophosphation ist ein solcher; er kann aber nicht für die gesamte Inhibition verantwortlich gemacht werden. Sowohl anionische als auch kationische Inhibitoren sind vorhanden, wobei die Kationen den Hauptanteil ausmachen. Folgende Ionen erwiesen sich in einer physiologischen Konzentration als Inhibitoren synthetischer Systeme: P7O 7 3− , HCO 3 − , SiO 4 1− , CrO 4 2− , Mg2+, Zn2+. Zusammengenommen verursachten diese Ionen eine Gesamtinhibition ähnlich derjenigen des Plasmas.
    Notizen: Abstract The calcifying activities of biological fluids can be measured,in vitro andin vivo, by their ability to reharden softened blocks of tooth enamel. The activity is expressed in terms of the calcium (and phosphate) concentrations of synthetic calcifying solutions of known concentration and activity. A typical human plasma had an activity corresponding to that of a solution of the following concentration: calcium, 0.70 mM; Ca/P, 1.67 and fluoride, 0.05 mM. The relatively low activity of serums and plasmas was shown to arise from the presence of a number of ionic inhibitors. Pyrophosphate ion is one such inhibitor but cannot account for the major inhibition. Both anionic and cationic inhibitors were shown to be present, with the cations respresenting the major portion. The following ions at their reported physiological concentration were shown to be inhibitors in synthetic systems: P7O 7 4− , HCO 3 − , SiO 4 2− , CrO 4 2− , Mg2+, Zn2+. In combination, these ions caused a total inhibition similar to those for plasmas.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 3 (1969), S. 266-273 
    ISSN: 1432-0827
    Schlagwort(e): Calcification ; Arteries ; Membranes ; Elastic tissue
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Avec la modification d'une méthode de von Kossa nous avons macroscopiquement representé les dessins de calcification de la membrane élastique intérieure, ainsi que les grosses artères du bassin, des artères des extrémités inferieures, des artères du bras, de la rate et des reins. Dans les artères du type élastique, dans les A.a. ilicae communes et internae, se présentaient les dégénérations calcaires de la membrane élastique intérieure sous forme d'incrustations noires arrondies ou polygonales qui ont été formes en groupes. Elles étaient toujours présentes chez des enfants agés de plus de trois mois et chez des aux adultes. Dans les artères musculaires, se montraient les parties calcifiées de la membrane élastique intérieure en forme de «bandes de calcaire» noires et groupes en paires le long des bordures des fissures de la membrane. Dans le cas où existait une calcinose forcée, on pouvait montrer avec cette méthode tout le système de fissures de la mambrane élastique intérieure. Chez tous les morts âgés de 10 à 20 ans, nous avons trouvé des bandes de calcaire dans les artères musculaires des extrémités inferieures. Ces bandes de calcaire ont été constatées aussi dans des personnes plus âgées. Au point de la fusion des bandes de calcaire et des incrustations calcaire polygonales des dépôts calcaires en forme de feuille («feuilles de calcaire») se forment dans la membrane elastique. Les bandes de calcaire et les feuilles de calcaire représentent des points de cristallisation pour des dépôts calcaire granuleux. Ils se forment dans la plupart des cas sur le la côté externe tourné vers la media.
    Kurzfassung: Zusammenfassung Mit einer modifizierten von Kossa-Methode wurden die Verkalkungsmuster der inneren elastischen Membran der großen Beckenarterien, der Arterien der unteren Extremität, der Oberarm-, Milz-und Nierenarterien makroskopisch dargestellt. In den Arterien vom elastischen Typ, i.e. in den Aa. ilicae communes et internae, erschienen die Verkalkungen der inneren elastischen Membran als schwarze rundliche oder polygonale Inkrustationen, die zu Gruppen angeordnet waren. Sie wurden häufig bereits bei Neugeborenen festgestellt. Bei Kindern, die älter waren als 3 Monate und bei Erwachsenen lagen sie stets vor. — In den muskulären Arterien traten die verkalkten Anteile der inneren elastischen Membran makroskopisch als schwarze paarweise angeordnete „Kalkbänder” entlang den Rändern vorgebildeter Membranspalten auf. Bei ausgeprägter Calcinose konnte mit der angewandten Methode das gesamte Spaltensystem der inneren elastischen Membran dargestellt werden. Kalkbänder wurden in den muskulären Arterien der unteren Extremität bei allen 10–20 Jahre alten Verstorbenen vorgefunden und waren auch in den nachfolgenden Altersstufen stets vorhanden. Beim Zusammenfluß von Kalkbändern und polygonalen Kalkinkrustationen entstehen in der inneren elastischen Membran folienartige Kalkablagerungen („Kalkfolien”). Die Kalkbänder und Kalkfolien stellen Kristallisationspunkte für körnige Kalkablagerungen dar, die zumeist an ihrer äußeren, der Media zugekehrten Seite entstehen.
    Notizen: Abstract Calcification patterns of the internal elastic membrane of the main pelvic arteries, lower limb arteries, brachial, splenic and renal arteries were demonstrated grossly by a modified von Kossa technique. In the elastic segment in the common and internal iliac arteries, the membrane calcification appeared as groups of roundish or polygonal incrustations. They were found frequently in newborns, and were always present in infants of more than three months, as well as in adults. In the muscular arteries, the calcified parts of the internal elastic membrane appeared grossly as pairs of bands (“calcific bands”) along the edges of the pre-existing gaps in this membrane. When calcification was pronounced, the whole pattern of the membrane gaps could be demonstrated by the method used in this study. Calcific bands were found in the muscular arteries of the lower limbs in all 10–20 year-old subjects, and were always present in the older age groups. The confluence of calcific bands or polygonal membrane incrustations found in the iliac arteries lead to sheet-like membrane calcification. The calcific bands and sheets represent crystallizing points for grain-like calcific deposits, which appear later on the medial surface.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 3 (1969), S. 363-365 
    ISSN: 1432-0827
    Schlagwort(e): Calcification ; Mitochondria ; Protozoa
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 3 (1969), S. 38-54 
    ISSN: 1432-0827
    Schlagwort(e): Epiphyseal cartilage ; Calcification ; Apatite crystals ; Organic/Inorganic relationships
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Les rapports entre composants organiques et inorganiques du cartilage ont été étudiés au niveau des épiphyses tibiales chez des rats de 5 jours et au niveau des jonctions costo-chondrales chez des cobayes d'un mois. Voici les principaux résultats auxquels on est parvenu: (a) Dans les zones où la calcification s'amorce les cristallites d'apatite sont susceptibles d'être facilement éliminés des coupes en araldite et en glycol methacrylate (GMA) après traitement pendant une heure par une solution d'acide formique au 2%. (b) Les zones décalcifiées sont douées d'une faible densité aux électrons et vont exemptes d'une structure quelconque. Seulement la fixation à l'osmium peut révéler du matériel amorphe. (c) Indépendemment du fixateur et du moyen d'inclusion, les coupes décalcifiées, traitées par l'acétate d'uranyl et/ou par le citrate de plomb, montrent de fines structures allongées dont l'aspect est semblable à celui des cristallites. (d) Ces structures ainsi qu'un fond dense interposé prennent l'acide phosphotungstique (PTA) dans les coupes en GMA, une méthode celle-ci qui met en évidence les polysaccharides. (e) Le fond dense ne prend plus le PTA après traitement par la hyaluronidase et en même temps les structures semblables au cristallites apparaissent plus faibles. Après traitement par l'acétate d'uranyl et le citrate de plomb, l'attaque par la hyaluronidase ne produit aucune modification appréciable. Au contraire l'aspect des structures semblables aux cristallites apparait modifié par la digestion à la papaïne. (f) Quand la décalcification à l'EDTA précéde l'enrobage, des amas de matériel fibrillaire se mettent en évidence dans les zones où la calcification s'était amorcée. L'ensemble de ces résultats permet d'établir la nature organique des structures semblables au cristallites et porte aussi à admettre que celles-ci soient formées par de fins filaments cylindriques (digérés par la papaïne) entourés, et probablement engainés par del polysaccharides (digérés par la hyaluronidase et prennant le PTA dans les coupes en GMA).
    Kurzfassung: Zusammenfassung Die Wechselbeziehungen zwischen den organischen und inorganischen Substanzen des verkalkenden Knorpels wurden in der tibialen und femuralen Epiphyse 5 Tage alter Ratten und in den Rippen 1 Monat alter Meerschweinchen untersucht. Die Hauptergebnisse waren: a) Die Hydroxyapatitkristalle der Frühverkalkungszonen können in Araldit- wie auch in Glycolmethylacrilatschnitten (GMA) mit einer lstündigen Behandlung durch 1% ige Ameisensäure leicht entfernt werden. b) Die entkalkten Zonen haben eine sehr niedrige Elektronendichte und enthalten keine sichtbaren Festkörper. Nach Fixierung mit Osmiumsäure kann man darin ein formloses Material erkennen. c) Eine Färbung der Schnitte mit Uranacetat und Bleicitrat, welche von den Fixier- und Einbettungsmitteln nicht beeinträchtigt wird, zeigt feine, längliche Körper (“Kristallgeister”) an, welche morphologisch den Kristallen von Hydroxyapatit gleichen. d) Die Färbung der GMA-Schnitte mit Phosphowolframsäure (PWS), eine Methode welche Polysaccharide anzeigt, hob diese “Kristallgeister” besonders hervor und demonstrierte auch eine dichte dazwischenliegende Grundsubstanz. e) Diese Substanz ist nach Behandlung mit Hyaluronidase nicht mehr färbbar mit PWS; die Färbbarkeit der “Kristallgeister” wird dabei jedoch nur verringert. Die Hyaluronidasebehandlung verändert die Uranacetat- und Bleicitratfärbung nicht. Die Feinstruktur der “Kristallgeister” wird durch Papainbehandlung sehr angegriffen. f) Falls die Schnitte vor dem Einbetten mit EDTA entkalkt werden, können Faserbündel in den Frühzonen der Verkalkung nachgewiesen werden. Diese Ergebnisse bestätigen die organische Natur der “Kristallgeister”. Sie beweisen auch, daß dieselben aus feinen Proteinstäbchen bestehen (verdaulich in Papain) und von Polysacchariden umgeben und vielleicht auch überzogen sind (verdaulich in Hyaluronidase und anfärbbar mit PWS).
    Notizen: Abstract The organic/inorganic relationships in calcifying cartilage have been studied in tibialfemoral epiphyses of 5-day-old rats and in costochondral junctions of 1-month-old guinea pigs. The main results are: (a) Apatite crystallites in areas of early cartilage calcification are easily removed from araldite and glycol methacrylate (GMA) sections by 1-hour treatment with 2% formic acid. (b) The decalcified areas have a very low electron density and do not contain recognizable structures. Only after osmium fixation can an amorphous material be found in them. (c) Independently from the fixative and the embedding medium, staining decalcified areas with uranyl acetate and/or lead citrate reveals thin, elongated structures (crystallite ghosts) similar in shape to apatite crystallites. (d) These crystallite ghosts and a dense background are stained by phosphotungstic acid (PTA) in GMA sections, a method which reveals polysaccharides. (e) The dense background is no longer stained by PTA after hyaluronidase digestion and the stainability of the crystallite ghosts is reduced. After uranyl acetate/lead citrate staining there are no recognizable changes due to hyaluronidase. But, on the other hand, the fine structure of the crystallite ghosts is modified by papain digestion. (f) Clusters of fibrillar material are present in the areas of early calcification when EDTA decalcification is carried out before embedding the specimens. These results confirm the organic nature of the crystallite ghosts and suggest that they are formed by thin, rod-like protein/like structures (digested by papain) surrounded, and probably sheathed, by acid polysaccharides (digested by hyaluronidase and stained by PTA in GMA sections).
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 4 (1969), S. 136-146 
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Calcification ; Osteoblasts ; Osteoclasts ; Poultry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé L'activité des cellules osseuses et la composition du fémur de pondeuses furent examinées pendant sept jours de déficience calcique (diète contenant 0,13% de calcium) et sept jours de réplétion (diète contenant 3,2% de calcium). Du point de vue histologique, seul l'os cortical donnait des signes nets de résorption et d'activité ostéoclastique. Le nombre d'ostéoclastes dans l'os médullaire différait peu des valuers témoin pendant les périodes de déficience et de réplétion subséquente, sauf pour une augmentation significative au premier jour de déplétion. L'effect histologique le plus important dans l'os médullaire était une augmentation marquée en nombre d'ostéoblastes aux troisième, cinquième, et un peu moins au septième jours de déplétion. Le nombre d'ostéoblastes était en corrélation positive avec la teneur de l'os médullaire en ostéoide et négative avec son degré de calcification. L'activité de l'os médullaire en phosphatase alcaline augmentait avec la longueur de la déficience calcique. Un jour après le retour des pondeuses à une diète contenant 3,2% de calcium, la calcification de l'os médullaire avait augmenté de façon significative, le nombre d'ostéoblastes avait diminué au niveau ou au-dessous du niveau de contrôle et l'activité de la phosphatase alcaline avait baissé considérablement. L'importance de ces résultats est discutée par rapport au controle des populations des cellules dan l'os et au rôle de l'os médullaire.
    Kurzfassung: Zusammenfassung Die Zahl der Knochenzellen und die Zusammensetzung des Femurs von Legehennen wurden während einer siebentägigen Calciumentzugsperiode (Calciumgehalt des Futters 0,13%) und einer siebentägigen Ersatzperiode (Calciumgehalt des Futters 3,2%) untersucht. Histologisch zeigte nur die Cortex eindeutige Knochenresorption und osteoklastische Aktivität. Abgesehen von einer signifikanten Zunahme am 1. Tag des Calciumentzuges, variierte die Zahl der Osteoklasten im Markknochen sowohl während der Entzugs- als auch während der nachfolgenden Ersatzperiode wenig. Die wichtigste histologische Änderung im Markknochen bestand in einer starken Zunahme in der Zahl der Osteoblasten am 3., 5. und etwas weniger am 7. Tag der Entzugsperiode. Die Zahl der Osteoblasten zeigte eine positive Korrelation mit dem Osteoidgehalt des Markknochens und eine negative mit dem Grade seiner Verkalkung. Die Aktivität der alkalischen Phosphatase im Markknochen war desto größer je länger den Hennen die calciumarme Ration verfüttert worden war. Die Wiederverabreichung der Ration, welche 3,2% Calcium enthielt, verursachte innerhalb eines Tages eine signifikante Zunahme in der Verkalkung des Markknochens, ein Absinken der Osteoblastzahl auf die Kontrollwerte oder unter sie und eine drastische Verringerung der alkalischen Phosphataseaktivität. Die Bedeutung dieser Ergebnisse in bezug auf die Kontrolle des Knochenzellenbestandes und auf die Funktion des Markknochens wird diskutiert.
    Notizen: Abstract Bone cell activity and the composition of the femur of laying hens were studied during 7 days of calcium depletion on a 0.13% calcium diet and 7 days of calcium repletion on a 3.2% calcium diet. Histologically, only cortical bone showed clear signs of bone resorption and osteoclastic activity during the depletion period. The number of osteoclasts in medullary bone varied little from control values throughout both calcium depletion and repletion, except for a significant increase on the first day of depletion. The major histologicalchange in medullary bone was a marked increase in the number of osteoblasts on the third, fifth and, to a lesser extent, seventh, day of depletion. The number of osteoblasts in medullary bone was positively correlated with its osteoid content and negatively correlated with its degree of calcification. Alkaline phosphatase activity of medullary bone increased with the time the hens had been on the calcium-deficient diet. Returning the hens to the 3.2% calcium ration caused, within one day, a significant increase in medullary bone calcification, a decrease of osteoblast numbers to, or below, control levels, and a drastic reduction in alkaline phosphatase activity of medullary bone. The significance of these findings in relation to the control of bone cell populations and the functions of medullary bone is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 24
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 4 (1969), S. 101-112 
    ISSN: 1432-0827
    Schlagwort(e): Calcification ; Ligament ; Mollusc ; Aragonite
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Une étude de microscopie électronique est réalisée sur la formation et la structure du ligament interne deMytilus edulis etPinctada radiata. Cette partie du ligament est dérivée des cellules isthmiques qui sont de forme cylindrique irrégulière. Elles présentent un ergastoplasme bien développé et un appareil de Golgi, engagé dans l'élaboration de vésicules et granules qui s'incorporent au niveau de la conchioline. Les cristaux se forment au niveau du front de calcification, à la surface interne du ligament. Ils sont entourés par une enveloppe. Ils se présentent comme des monocristaux d'aragonite, allongés et en forme d'aiguilles, dispersés dans le ligament. Bien que les constituants de la carapace et du ligament soient identiques, il existe des différences concernant l'augmentation quantitative de conchioline et une diminution en nombre, forme diverse, groupement et croissance des cristaux. Ces différences sont probablement liées à la fonction spécialisée du ligament.
    Kurzfassung: Zusammenfassung Die Bildung und Struktur des inneren Ligamentes vonMytilus edulis undPinctada radiata wurden am Elektronenmikroskop untersucht. Dieser Teil des Ligamentes stammt von den Isthmuszellen ab, deren Form unregelmäßig säulenartig ist. Sie zeigen ein vorspringendes, rauhes endoplasmatisches Reticulum und einen Golgiapparat, welche sich mit der Bildung von Bläschen und Granula befassen, die schließlich in einem integralen Teil des Conchiolins eingebaut werden. Die Kristalle entstehen an der Calcifikationsgrenze an der inneren Oberfläche des Ligamentes und sind in Hüllen eingeschlossen. Sie bestehen aus langen, nadelförmigen, einzelnen Aragonit-Kristallen, die über das ganze Ligament verteilt sind. Obschon die Bestandteile der Muschel und des Ligamentes gleichartig sind, unterscheiden sich die beiden durch eine erhöhte conchiolinmenge, wie auch durch eine Abnahme der Anzahl der Kristalle, welche verschieden in der Form, in der Anordnung und im Wachstum sind. Dies alles ist vermutlich auf die spezielle Funktion des Ligamentes zurückzuführen.
    Notizen: Abstract An electron microscope study was made of the formation and structure of the inner ligament ofMytilus edulis andPinctada radiata. This part of the ligament is derived from the isthmus cells which are irregular columnar in shape. They exhibit a prominent rough endoplasmic reticulum and a Golgi apparatus, which are concerned with the elaboration of vesicles and granules eventually incorporated into an integral part of the conchiolin. The crystals arise at the calcification front at the inner surface of the ligament and are enclosed in envelopes. They consist of long, needle-shaped, single aragonite crystals widely dispersed in the ligament. Although the components of the shell and ligament are similar, differences between them consist of an increased amount of conchiolin, as well as a decrease in the amount, diversity of form, arrangement and growth of the crystals; all probably related to the specialized function of the ligament.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 25
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 4 (1969), S. 359-365 
    ISSN: 1432-0827
    Schlagwort(e): Metals ; Ions ; Buffers ; Calcification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé L'action de divers ions métalliques polyvalents sur les propriétés métastables d'un tampon calcifiable a été étudiée. A des concentrations de 1 μM ou moins, les ions Pb2+, F2+, Fe3+, Cr3+, Bi3+ et Al3+ déstabilisent le tampon. Il semble que les phosphates insolubles formés par ces ions déclanchent la précipitation de l'apatite. L'importance de ces résultats dans l'étiologie des calcifications pathologiques et la calciphylaxie est décrite.
    Kurzfassung: Zusammenfassung Die Wirkung von verschiedenen polyvalenten Metallionen auf die Metastabilität eines Calcifikationspuffers wurde untersucht. Bei Konzentrationen von 1 μM oder weniger wird der Puffer durch Pb2+, Fe2+, Fe2+, Cr3+, Bi3+ und Al3+ entstabilisiert. Die Resultate lassen vermuten, daß unlösliche Phosphate, die mit diesen Ionen entstehen, eine Fällung von Apatit veranlassen. Die Bedeutung dieser Befunde bei pathologischen Verkalkungen und Calciphylaxis werden besprochen.
    Notizen: Abstract The effect was studied of various polyvalent metal ions on the metastability of a calcification buffer. At concentration of 1 μM or less, Pb2+, Fe2+, Fe3+, Cr3+, Bi3+ and Al3+ ions were found to destabilize the buffer. The results suggest that insoluble phosphates formed by these ions initiate the precipitation of calcium apatite. The implications of these findings to pathological calcification and calciphylaxis are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 26
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 4 (1969), S. 39-47 
    ISSN: 1432-0827
    Schlagwort(e): Dehydroepiandrosterone ; Calcification ; Embryo ; Tissue Culture ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Les modes d'utilisation de glucose, le contenu de calcium et d'hydroxyproline et la densité cellulaire du perioste de les os frontaux d'embryons de poulet de 12 et 13 jours de developpement, cultivés sur coagulum de plasma, se presentant différenment à chaque âge. Cultivés avec sulfate de déhydroèpiandrostérone en concentration 1 mM, les frontaux de 12 jours montrent un synthese augmentée du matrice osseuse, celle de 13 jours se calcifient à une vélocité significativement plus grande que celle des os contôles. Le degré de calcification au quatrième jour de culture measuré par la relation calcium/hydroxyproline, suit un fonction lineáire avec le logarithme des doses de sulfate de dehydroepiandrostérone employées (0.5, 1,0 et 2,0 mM). Les renseignements obtenus indiquent que les frontaux de 13 jours, cultivés “in vitro” constituent modeles experimentaux appropriés pour étudier l'effet des androgénes sur le tissue osseux.
    Kurzfassung: Zusammenfassung Stirnbeine von Hühnerembryonen an ihrem 12. und 13. Entwicklungstag entnommen und in vitro kultiviert zeigen verschiedene Arten der Glucoseverwertung der Periostzellendichte, des Calcium- und Hydroxyprolingehaltes. Wird Dehydroepiandrosteronsulfat dem Medium in einer 1 mM-Konzentration zugegeben, so beteiligen sich die 12tägigen Stirnbeine vorwiegend an der Knochengewebesynthese, während die 13tägigen signifikant stärker verkalken als die Kontrollen. Gemessen an der Calcium/hydroxyprolin Ratio bildet die Verkalkung der 13tägigen Stirnbeine eine lineare Funktion mit den Logarithmen der verwendeten Dosen von Dehydroepiandrosteronsulfat (0,5, 1,0 und 2,0 mM). Das in vitro kultivierte 13tägige Stirnbein schein ein geeignetes Experimentiermodell zur Studie der Dehydroepiandrosteronsulfatwirkung auf das Knochengewebe zu sein, weil es das grundlegende Phänomen (erhöhte Verkalkung) wiedergibt, welches man auch bei mit Androgenen behandelten Menschen und Tieren beobachtet.
    Notizen: Abstract Chick embryo frontal bones at 12 and 13 days of development cultivatedin vitro exhibit different patterns of glucose utilization, periosteal cellular density and calcium and hydroxyproline content. When dehydroepiandrosterone sulfate is added to the medium at a concentration 1 mM, 12-day frontals engage primarily in osteoid tissue synthesis while 13-day frontals calcify at a significantly greater rate than controls. Measured with the ratio calcium/hydroxyproline, the calcification of 13-day frontals follows a linear function with the logarithm of the doses of dehydroepiandrosterone sulfate employed (0.5, 1.0 and 2.0 mM). The 13-day frontal bone cultivatedin vitro seems to be an adequate experimental model for the study of the effects of dehydroepiandrosterone sulfate on bone tissue because it reproduces the basic phenomenon (increased calcification) observed in man and animals treated with androgens.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 56 (1995), S. 140-144 
    ISSN: 1432-0827
    Schlagwort(e): Bone sialoprotein ; Collagen ; Hole zone ; Calcification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract Bone sialoprotein (BSP) has an affinity to collagen fibrils [25]. A role of carbohydrate chains in the affinity was examined by removing sialic acids of BSP. Neuraminidase treatment of the BSP increased the binding to collagen. Binding sites of BSP on collagen were examined by biochemical and electron-microscopic methods. Purified bovine BSP was labeled with biotin. Collagen α chains or CNBr peptides were separated by electrophoresis and transfered to nitrocellulose membranes. The membranes were incubated with the biotin-labeled BSP, and the bound BSP was visualized with avidin conjugated with alkaline phosphatase. The labeled BSP was preferentially bound to the α 2 chain, and peptides derived from α 2 chain. In another experiment, the labeled BSP was incubated with reconstituted native collagen fibrils. The mixture was put on a copper grid, reacted with avidin conjugated with gold particles, and observed with an electron microscope. The gold particles were seen mainly within hole zones of the fibrils. BSP bound to the α 2 chain within the hole zones may regulate the onset of calcification at hole zones and the cell binding to collagen fibrils.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 2 (1968), S. 1-19 
    ISSN: 1432-0827
    Schlagwort(e): Collagen ; Hydroxyapatite ; Keratin ; Enamel ; Calcification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 2 (1968), S. 60-66 
    ISSN: 1432-0827
    Schlagwort(e): Fluorides ; Topical/Pharmacodynamics ; Penicillin/Pharmacodynamics ; Calcification ; Physiologic/Drug Effects ; Rats
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé L'objet de ce travail était de comparer le phénomène de la maturation postéruptive dans les molaires des rats ordinaires et sans germes à qui on a donné à manger un régime «non-cariogène». On a étudié les effets de l'application topique du fluorure et de la nourriture de la penicilline sur la maturation. Les molaires des rats ordinaires (nourris d'un régime «chow» — aliment mixte pour les animaux préparé d'habitude sous la forme d'une farine ou en boulettes) traités topiquement avec une solution à 1% de NaF et les molaires des rats ordinaires nourris d'un régime «chow» complété avec la penicilline à 1% ont montré un degré de maturation significativement plus grand que les molaires des rats de la même portée nourris de «chow» et traités avec de l'eau. De l'autre côté, les molaires des rats sans germes traités topiquement avec une solution à 1% de NaF n'ont montré aucune différence significative dans le degré de maturation des molaires de rats de contrôle semblables traités topiqument avec l'eau. Ces résultats sont en accord avec l'hypothèse que dans un milieu normal le procédé de minéralisation (maturation) est opposé par un procédé de déminéralisation. Le procédé de déminéralisation est un résultat de la production d'acide par des bactéries qui métabolisent les aliments encastrés dans les «sulci» des molaires. On propose que dans les animaux ordinaires le fluorure et la penicilline peuvent influencer la maturation en empêchant le procédé de déminéralisation. Dans les animaux sans germes le procédé de déminéralisation est absent parce que la microflore orale est absente.
    Kurzfassung: Zusammenfassung Der Zweck dieser Arbeit war ein Vergleich des nach dem Durchbruch auftretenden Reifungsphänomens der Backenzähne von gewöhnlich und von keimfrei gehaltenen Ratten, die mit einer nicht-cariogenen Diät ernährt wurden. Es wurden die Auswirkungen von topisch angewendetem Fluorid, verbunden mit Penicillin-Fütterung auf die Reifung untersucht. Die Backenzähne der gewöhnlich gehaltenen Ratten (mit “Chow”-Diät ernährt), die mit einer 1%igen Na-Fluoridlösung topisch behandelt wurden, und solchen deren “Chow”-Diät zu 1% mit Penicillin versetzt wurde, zeigten einen erheblich größeren Reifungsgrad als die Backenzähne von Tieren des gleichen Wurfes, die nur mit der “Chow”-Diät und Wasser ernährt wurden. Diese Resultate stimmen mit der Hypothese überein, daß in einer normalen Umgebung dem Mineralisationsprozeß (Reifung) ein Demineralisationsprozeß entgegenwirkt. Der Demineralisationsprozeß ist durch eine Säureproduktion von Bakterien bedingt, welche die in die Zahnfurchen eingepreßten Nahrungsbestandteile metabolisieren. Es wird die Annahme vorgeschlagen, daß Fluoride und Penicillin bei den gewöhnlich gehaltenen Tieren die Reifung durch eine Inhibition des Demineralisationsprozesses beeinflussen. Bei keimfrei gehaltenen Tieren findet dagegen kein Demineralisationsprozeß statt, da die orale Mikroflora fehlt.
    Notizen: Abstract The purpose of this work was to compare the phenomenon of post-eruptive maturation in molars of conventional and germfree rats fed non-cariogenic diets. The effects of topical application of fluoride and feeding penicillin on maturation were studied. The molars of conventional rats (fed a chow diet) treated topically with a 1% NaF solution and the molars of conventional rats fed a chow diet supplemented with 1% penicillin showed a significantly greater degree of maturation than did the molars of littermate rats fed chow and treated with water. On the other hand, the molars of germfree rats treated topically with a 1% NaF solution showed no significant difference in degree of maturation from the molars of similar control rats topically treated with water. These data are consistent with an hypothesis that in a normal environment the mineralization (maturation) process is opposed by a demineralization process. The demineralization process is a result of production of acid by bacteria metabolizing the diet impacted in the sulci of molars. It is proposed that in conventional animals fluoride and penicillin may influence maturation by inhibiting the demineralization process. In the germfree animals the demineralization process is absent because the oral microflora is absent.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 2 (1968), S. 361-369 
    ISSN: 1432-0827
    Schlagwort(e): Calcification ; Hydroxyapatite ; Keratin ; Hair ; Electron diffraction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Certaines régions du cortex des fibres de kératine contiennent une proportion relativement élevée de matériel non kératinisé. L'orientation microfibrillaire dans ces régions est biaxiale et on y trouve, en outre, des zones de matériel amorphe. Les sels calciques, et en particulier l'hydroxyleapatite, sont étudiés par diffraction électronique qui permet de les localiser et de les identifier. En outre, cette technique permet de déterminer la fréquence de cellules nonkératinisées dans la partie interne du cortex et de les comparer avec les propriétés histochimiques de cette région. Une comparison est effectuée entre la calcification de la kératine et celle intéressant le collagène et l'élastine.
    Kurzfassung: Zusammenfassung Es wird gezeigt, daß Bereiche im Cortex von gewissen Keratinfasern einen relativ hohen Anteil an nichtkeratinösem Material enthalten. Ferner konnte nachgewiesen werden, daß die Orientierung der Mikrofibrillen in diesen Bereichen biaxialer Art ist, und daß Bezirke von amorphem Material vorhanden sind. Die Calciumsalze und insbesondere das Hydroxyapatit konnten mit Hilfe der Elektronendiffraktion lokalisiert und identifiziert werden. Diese Methode hat sich auch als wertvoll erwiesen, um die Wechselbeziehung zwischen dem Vorkommen von einigen nichtkeratinisierten Zellen im Cortexinnern und den histochemischen Eigenschaften dieser Regionen zu zeigen. Ein Vergleich wird gemacht zwischen der Umgebung der Verkalkungsstellen im Keratin mit derjenigen im Kollagen und im Elastin.
    Notizen: Abstract Regions in the cortex of some keratin fibres are shown to contain a relatively high proportion of non-keratinous material. The microfibrillar orientation in these regions is shown to be biaxial in nature and, in addition, areas of amorphous material are reported. Calcium salts, in particular hydroxyapatite, have been located and identified using electron diffraction, which has also proved valuable in correlating the incidence of some non-keratinised cells in the inner part of the cortex with the histochemical properties of this region. A comparison is made between the environment of the sites of calcification in keratin with those in collagen and elastin.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 2 (1968), S. 214-228 
    ISSN: 1432-0827
    Schlagwort(e): Calcinosis ; Calcification ; Cartilage ; Collagen ; Mineral metabolism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Les facteurs, influençant la vitesse et l'intensité du phénomène d'association des ions calcium et phosphates avec des fibres contenant du collagène, et préparés à partir du tendon de boeuf par deux méthodes d'extraction différentes, ont été étudiés. Les fibres, obtenues par ces deux méthodes, nécessitent spécifiquement du phosphate pour absorber du calcium et vice versa. L'absorption ionique des deux préparations est inhibée par du Mg++, du pyrophosphate et un peptide acidique, isolé du sérum humain. Alors que les fibres contenant du collagène, préparées selon les deux méthodes, présentent une absorption ionique à des vitesses sensiblement identiques, seule une des méthodes donne une matrice réagissant positivement à la technique de coloration au nitrate d'argent de von Kossa. Etant donné que les deux critères de calcification sont intéressés de façon identique par des conditions de réaction et par des inhibiteurs, il apparait que les deux facteurs sont des manifestations de différents stades de calcification et que des études d'absorption ionique fournissent une base quantitative d'appréciation de la calcification, pouvant être d'importance pour l'étude du mécanisme et de contrôle de la minéralisation tissulaire.
    Kurzfassung: Zusammenfassung Überprüft wurden die Faktoren, welche Geschwindigkeit und Ausmaß der Erscheinung beeinflussen, wobei Calcium- und Phosphationen sich mit den kollagenhaltigen, durch zwei verschiedene Extraktionsmethoden aus Rindersehnen gewonnenen Fasern eng zusammenbinden. Die mit beiden Methoden zubereiteten Fasern benötigen spezifisch Phosphat für die Calciumaufnahme und Calcium für die Phosphataufnahme. Die Ionenaufnahme beider Arten wird durch Mg++, Pyrophosphat und saure, aus dem menschlichen Serum isolierte Peptide gehemmt. Während die nach beiden Methoden präparierten kollagenhaltigen Fasern eine Ionenaufnahme von beinahe gleicher Geschwindigkeit verursachen, ergibt nur eine dieser Methoden eine Matrix, die mit der Silbernitratfärbung nach vonKossa positiv reagiert. Da beide Calcifikationskriterien gleicherweise durch Reaktionsbedingungen und Inhibitoren beeinflußt werden, wird daraus geschlossen, daß beide Erscheinungen verschiedener Stadien des Gesamtcalcifikationsprozesses sind. Untersuchungen über die Ionenaufnahme ergeben eine quantitative Angabe der Verkalkung, welche für die Erforschung des Mechanismus und der Kontrolle der Mineralisation der Gewebe wichtig sein könnte.
    Notizen: Abstract Factors that influence the rate and extent of the phenomenon in which calcium and phosphate ions become firmly associated with collagen-containing fibers prepared from beef tendon by two different extraction methods have been investigated. The fibers produced by both methods specifically require phosphate for calcium uptake and calcium is required for phosphate uptake. Ion uptake by both types is inhibited by Mg++, pyrophosphate, and an acidic peptide isolated from human serum. Whereas the collagen-containing fibers prepared by both methods induce ion uptake at nearly identical rates, only one of the methods produced a matrix that gives a positive response to the silver nitrate staining technique of von Kossa. Since both criteria of calcification are similarly influenced by reaction conditions and inhibitors, it is concluded that both are manifestations of different stages of the overall calcification process and that studies of ion uptake provide a quantitative assessment of calcification which could be of importance for investigating the mechanism and control of tissue mineralization.
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  • 32
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 56 (1995), S. 403-407 
    ISSN: 1432-0827
    Schlagwort(e): Bone sialoprotein ; Fibronectin ; Type I colfagen ; MC3T3-E1 cells ; Calcification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract Bone sialoprotein (BSP) containing an Arg-Gly-Asp cell-binding sequence was purified from bovine bone 4 M guanidine-HCl extract after HCl demineralization by a series of chromatographic procedures. When this protein was coated on culture dishes in the presence of type I collagen, it increased both DNA content and alkaline phosphatase (ALP) activity in osteoblast-like MC3T3-E1 cells, and stimulated calcification in the cells, whereas fibronectin, another cell-binding protein, showed a marked increase in the DNA content but had little effect on the ALP activity. These findings suggest that BSP is mitogenic for preosteoblasts and differentiating the cells into osteoblasts, thereby stimulating bone calcification
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Journal of industrial microbiology and biotechnology 17 (1996), S. 328-345 
    ISSN: 1476-5535
    Schlagwort(e): hyphomycetes ; ascomycetes ; taxonomy ; ecology ; stream biology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract There are more than 600 species of freshwater fungi with more known from temperate, as compared to tropical regions. These includeca 340 ascomycetes, 300 deuteromycetes, and a number of lower fungi which are not discussed here.Aniptodera, Annulatascus, Massarina, Ophioceras andPseudohalonectria are common freshwater ascomycetes, which appear to be well adapted for this lifestyle either in their ascospore types or their competitive-degradative characters. The most common genera of wood-inhabiting deuteromycetes includeCancellidium, Dactylaria, Dictyosporium andHelicomyces. They are categorized into four groups depending on their form and life style: the ingoldian hyphomycetes; the aero-aquatic hyphomycetes; the terrestrial-aquatic hyphomycetes; and the submerged-aquatic hyphomycetes. The adaptations of aquatic fungi for their dispersal and subsequent attachment to new substrates are discussed.
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  • 34
    ISSN: 1573-3017
    Schlagwort(e): contamination risks ; fish ; Mississippi River ; ecological factors ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik
    Notizen: Abstract We compared contamination levels in fish from contaminated and uncontaminated floodplain swamps of the lower Mississippi River to assess differences in contamination risks between swamps, across different taxonomic and ecological groupings of fishes within and between swamps, and with seasonality in river stage. Fish tissue levels of inorganic contaminants were substantially lower than environmental levels in both swamps, suggesting either that fish were not uptaking these contaminants, or they were effectively eliminating the contaminants from their bodies. Tissue levels of organic contaminants were high relative to environmental levels, suggesting that these contaminants were bioaccumulating. Organic contaminants were significantly higher in fish from the contaminated swamp (Devil's Swamp) than in fish from a reference swamp up river (Tunica Swamp). Because the organic contaminants were largely confined to sediments, we expected bottom-oriented fishes to have higher concentrations than pelagic fishes. Assuming that uptake was primarily through the food chain, we expected top predators to exhibit higher concentrations than low-level consumers. We also expected year- round swamp residents to exhibit higher accumulations than more transitory users of backswamp habitat. However, organic contaminant levels did not differ in the directions expected for any of these groupings. We did observe differences in organic contaminant levels within and between swamps for different taxonomic groupings of fishes (species and genera). Some taxa occupying low to middle positions in the food web (e.g., gizzard shad, Lepomis spp.) exhibited higher concentrations than taxa near the top of the food web. Within Devil's Swamp, organic contaminant levels were significantly higher at low river stage, when fish were confined to the swamp, than at high river stage, when fish were free to move between the river and the swamp. We caught more species and more fish per unit effort in Devil's Swamp than in Tunica Swamp, contrary to expectations if contaminants in the former were negatively impacting population and community structure. Species richness differences between swamps were a consequence of catch differences, with higher catch corresponding to inclusion of more rare species. The lower catch in Tunica Swamp may have resulted from physical modifications of its waterways to support agriculture and hunting. The results of this study underscore the importance in factoring information on the taxonomy and ecology of organisms, and seasonal changes in environmental conditions, into assessments of contamination risks.
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  • 35
    ISSN: 1871-4528
    Schlagwort(e): subspecies ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary A joint Mexico/United States expedition collected wild potato (Solanum sect.Petota) germplasm in Mexico between August 1–31, 1993. The purpose of the expedition was to expand germplasm and herbarium collections ofS. bulbocastanum andS. cardiophyllum. Collections were made from west-central to southern Mexico, and comprised 19 true seed and 37 tuber collections (45 collections in total) of 9 species and two putative natural hybrids.
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  • 36
    ISSN: 1618-2545
    Schlagwort(e): Bruguiera gymnorrhiza ; ecology ; Lanceispora amphibia ; mangrove ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Lanceispora amphibia gen. et sp. nov. in the Amphisphaeriaceae is described from senescent and fallen leaves ofBruguiera gymnorrhiza in mangrove forests in the Southwest Islands, Japan. The fungus produces immersed ascomata in leaf tissue, cylindrical asci with an apical ring staining blue with iodine, and oblanceolate ascospores with a septum above the middle. Studies on the fungal succession on the mangrove leaves revealed thatL. amphibia infects senescent leaves on the tree and inhabits intertidal fallen leaves, showing the highest frequency of occurrence at the late stage of decomposition. In culture the optimal conditions for hyphal growth were 20 ppt salinity and 30°C, and those for sexual reproduction were 10 ppt salinity and 25°C. Growth at 0 ppt (fresh water) was depressed. The fungus has amphibious habits, growing on the tree and in intertidal water; and it is adapted to the high osmotic conditions in leaf tissues of the mangrove tree and to the subtropical, brackish water environment of mangrove forests.
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 38 (1997), S. 323-328 
    ISSN: 1618-2545
    Schlagwort(e): Bauhinus ; Microbotryum ; taxonomy ; Ustilago ; ustomycetes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A study of the type specimen ofUstilago jehudana resulted in the correction of the diagnosis. The sori are localized in the host gynoecium but not in the anthers. Morphological characters of the sori and ustospores of the later describedU. moenchiae-manticae are identical with these ofU. jehudana. Ustilago moenchiae-manticae is reduced here to a synonym ofU. jehudana. The smut is reported as new to Bulgaria on a new host, viz.,Moenchia erecta. A new combination,Bauhinus jehudanus, is proposed.
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  • 38
    ISSN: 1618-2545
    Schlagwort(e): Aphyllophorales ; ribosomalDNA ; synnematous hyphomycete ; taxonomy ; Tretopileus sphaerophorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Tretopileus sphaerophorus, a synnematous hyphomycete with basidiomycetous affinities was newly isolated from the decaying petiole and peduncle ofCocos nucifera collected in Depok, Indonesia. The species produced first a bulbil as a propagule on the top of a synnema. After the bulbil had fallen, the synnema proliferated about seven times to produce new bulbils, each time making conspicuous nodes at the upper part. By careful morphological observation, clamp connections were confirmed on the hyphae in the specimens and culture. In culture, each hyphal cell with or without a clamp was found to be dikaryotic by DAPI nuclear staining. Germination of the bulbils occurred first from projecting hyphal tips on their upper surface, which have been treated as germ pores. The inner structure of the bulbils, the hyaline mucus of the bulbils, and conidium-like hyphal fragments were also examined. Phylogenetically,T. sphaerophorus was inferred to be related to the Aphyllophorales based on the nuclear encoded small subunit (18S) rDNA using the homology search system (FASTA) and the neighbour-joining method.
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  • 39
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 39 (1998), S. 97-104 
    ISSN: 1618-2545
    Schlagwort(e): Loculoascomycetes ; phyllachoraceae ; phyllachorales ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The order Phyllachorales contains ascomycetous fungi of considerable economic importance. The group is represented mostly by foliar parasites which produce perithecia under a clypeus, inside a stroma, or do not produce any stromatic tissue. A major taxonomic problem with this order is the lack of reliable morphological characters that clearly delimit the entire group. The main purpose of this review is to provide a clear picture of the taxonomic relationships of the order Phyllachorales, along with a key to the most important genera in the family Phyllachoraceae.
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 40 (1999), S. 73-80 
    ISSN: 1618-2545
    Schlagwort(e): Mycena auricoma ; Mycena sect.Radiatae ; Mycena spinosissima ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two lignicolous species ofMycena (Agaricales, Basidiomycetes) are described and illustrated from eastern, Japan:Mycena auricoma sp. nov., forming ephemeral coprinoid basidiomata and belonging to sectionRadiatae, was found on a dead fallen twig ofQuercus serrata. It appears to close to a Malaysian species,“Trogia” crinipelliformis. Mycena spinosissima in sectionSacchariferae, new to Japan, was collected from dead bark ofAphananthe aspera, a dead fallen inflorescence ofCryptomeria japonica, and a dead fallen twig ofQuercus serrata.
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  • 41
    ISSN: 1618-2545
    Schlagwort(e): cellular slime molds ; dictyostelids ; macrocyst ; mating system ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Macrocyst formation in the sexual cycle was found in three dictyostelid species:Dictyostelium monochasioides, Polysphondylium candidum, andP. pseudo-candidum. Mating tests suggested thatD. monochasioides andP. pseudocandidum were heterothallic andP. candidum was homothallic. The primary walls of macrocysts had partially or fully degenerated, while the inner walls, believed to be tertiary walls, showed an undulate structure.
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 36 (1995), S. 431-438 
    ISSN: 1618-2545
    Schlagwort(e): Atkinsiella dubia ; Halocrusticida ; Japan ; marine fungus ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Atkinsiella dubia, isolated from the mantle of abalone (Haliotis sieboldii), is described and illustrated as a new record from Japan. The fungus was also obtained from the gills of swimming crab (Portunus trituberculatus). Six other species of the genusAtkinsiella have hitherto been reported from various aquatic animals. The fungus is distinguished from the other six species by the morphology of its mycelia and the process of zoospore production. The most distinctive feature is that zoospores in the first motile stage ofA. dubia encyst in zoosporangia, unlike the other species. We therefore proposeHalocrusticida gen. nov. (Lagenidiales, Haliphthoraceae) for the other six species ofAtkinsiella. A key to species of the genusHalocrusticida is provided.
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  • 43
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 37 (1996), S. 173-185 
    ISSN: 1618-2545
    Schlagwort(e): Geminago ; Geminago nonveilleri ; Mycosyrinx ; taxonomy ; Ustilaginales
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The revision of the genusMycosyrinx resulted in the recognition of three species, all on Vitaceae:M. cissi (type onCissus sicyoides), M. arabica (type onCissus quadrangularis), andM. microspora (type onCissus afzelii), and in the description of a new genus. After a short historical review, the genusMycosyrinx is characterized and descriptions, synonyms, ilustrations, and a key are given for the three recognizedMycosyrinx species.Mycosyrinx globosa (nomen nudum, onCissus sp.) is considered to be immatureM. microspora. Lectotype is selected forSchizonella colemani (=M. arabica). A short characterization is given for the generaSchizonella andUstacystis and they are compared withMycosyrinx andSchroeteria. ForM. nonveilleri (type onTriplochiton scleroxylon, Sterculiaceae) a new genus,Geminago, is proposed. A key to the pair-spored genera of Ustilaginales is given.Mycosyrinx osmundae (type onOsmunda regalis, Pteridophyta, Osmundaceae) and its var.cinnamomae are excluded fromMycosyrinx.
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  • 44
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 37 (1996), S. 255-259 
    ISSN: 1618-2545
    Schlagwort(e): cleistothecial ascomycete ; Lasiobolidium gracile ; soil fungus ; taxonomy ; USA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Lasiobolidium gracile isolated from a soil sample collected from California, USA is described as a new species. This species is characterized by yellowish brown to reddish brown, nonostiolate ascomata with numerous, long straight appendages and a translucent peridium, subglobose to broadly clavate asci, hyaline to pale yellowish brown, ellipsoidal ascospores. It differs from the other species ofLasiobolidium in the straight and narrow appendages and the large ascospores. A key is presented separating the seven known species.
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  • 45
    ISSN: 1618-2545
    Schlagwort(e): Chaetomidium ; Chaetomidium heterotrichum ; cladistic analysis ; systematics ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A species of the genusChaetomidium was isolated from fallen leaves of an unknown tree during a mycofloral survey of materials from the ‘Gran Sabana’ region in Southeastern Venezuela. The species was identified asC. heterotrichum. Identification was based on the perithecium lacking a neck and ostiole, the peridium being composed of textura angularis cells, the perithecium being covered with hairs and setae at the apex, and by 4-spored asci containing uniporate ascospores. The anamorph was intermediate betweenChalara andAcremonium sect.Chaetomioides. This is the first report of this species in Venezuela and only the second timeC. heterotrichum has been found. An illustrated description ofC. heterotrichum and a key to eight recognized species ofChaetomidium, based on morphological characters in the literature, are provided. The results of a cladistic analysis of 12 available morphological characters of the genus revealed two main groups, each based on the two characters ‘ascospore shape’ and ‘peridial wall type’. The ascomatal hairs had little influence on the species grouping. With the exception ofC. heterotrichum, the remaining species ofChaetomidium were monophyletically supported in 73% of the bootstrap replicates.Chaetomidium heterotrichum was the basal ingroup taxon and formed a sister group to the other species in the genus.
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 38 (1997), S. 55-69 
    ISSN: 1618-2545
    Schlagwort(e): discomycetes ; ITS rDNA phylogeny ; morphology ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The systematics ofScleromitrula andVerpatinia of the family Sclerotiniaceae is reevaluated on the basis of morphological, cultural and molecular criteria.Scleromitrula shiraiana, Verpatinia species andCiborinia candolleana share gross morphological, microanatomical and cultural features which clearly distinguish them from the closely relatedCiborinia andRutstroemia species. Phylogenetic analyses of sequences from the internal transcribed spacer region (ITS1, ITS2, and the 5.8S gene) of nuclear ribosomal DNA demonstrate that the stipitate-capitate specimens ofScleromitrula andVerpatinia species plus the stipitate-cupulateCiborinia candolleana constitute a monophyletic clade separate from a clade including the type species ofCiborinia. Scleromitrula is emended to includeS. shiraiana, the new speciesS. rubicola, C. candolleana, and specimens formerly assigned toVerpatinia. A key to the accepted species ofScleromitrula is provided.
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  • 47
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 38 (1997), S. 71-73 
    ISSN: 1618-2545
    Schlagwort(e): Ceratobasidiaceae ; Japan ; taxonomy ; Ypsilonidium bananisporum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Ypsilonidium bananisporum sp. nov. belonging to Ceratobasidiales is described and illustrated. This fungus has all the characteristics of the genusYpsilonidium including reticulate-hypochnoid basidiomes, broad hyphae branching at right angles, broadly clavate basidia with two sterigmata, and basidiospores germinating by repetition. It differs from all hitherto known species in the genus by producing suballantoid to banana-shaped basidiospores, measuring 19.5–22×5.5–6 μm.
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  • 48
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 38 (1997), S. 87-89 
    ISSN: 1618-2545
    Schlagwort(e): Israel ; Mycomycetes ; Physarales ; Stemonitales ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Ten taxa of myxomycetes growing mainly withEucalyptus, oak and pine are described. They were found in Upper Galilee, Mt. Carmel and Central parts of the country and all are new to Israel.
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  • 49
    ISSN: 1618-2545
    Schlagwort(e): hyphomycetes ; identification ; taxonomy ; Tuberculariaceae ; Tuberculariales
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Mycoleptodiscus terrestris from black pepper roots in the Dominican Republic is described together with some notes and photomicrographs.
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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 38 (1997), S. 429-431 
    ISSN: 1618-2545
    Schlagwort(e): coelomycete ; Japan ; Microsphaeropsis rugospora ; soil fungus ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Abstract In an exploratory survey of soil-borne mitosporic fungi as producers of secondary metabolites useful to the pharmaceutical industry, a pale yellow pycnidial coelomycete was encountered and isolated on potato-dextrose agar. The fungus was characterized as follows: rapid growth on common media, conidiomata which are non-pulvinate, semi-immersed to immersed, nearly globose, glabrous, with a slightly papillate ostiole; pale yellowish brown, translucent, membranaceous peridium; discrete, ampulliform, monophialidic conidiogenous cells; and onecelled, dark brown, globose, thick-walled, rugose conidia which germinate very easily. In accordance with this profile, our isolate is included in the genusMicrosphaeropsis Höhnel. (Morgan-Jones, 1974a, b; Sutton, 1977, 1980; Morgan-Jones and White, 1987; Heiny et al., 1992; Katumoto, 1992). However, it proved to be sufficiently different from all described species ofMicrosphaeropsis to warrant its description as a new species.
    Notizen: Abstract A new species ofMicrosphaeropsis (Sphaeropsidales, Coelomycetes),M. rugospora, is described and illustrated. This fungus is characterized by its rapid growth on common media such as oatmeal and potato-carrot agars; semi-immersed to immersed, nearly globose, papillate pycnidias; pale yellowish brown, translucent, membranaceous peridium; monophialidic, ampulliform conidiogenous cells; and one-celled, dark brown, globose conidia ornamented with distinct tubercles. The holotype was isolated from the cultivated soil in Tanegashima Island, southern Japan.
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  • 51
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 39 (1998), S. 31-36 
    ISSN: 1618-2545
    Schlagwort(e): Mycogloea ; Platygloea ; Platygloeaceae ; Platygloeales ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Three new species ofMycogloea are described and illustrated; they are:M. amethystina from Canada,M. nipponica, from Japan, andM. bullata from Thailand.Mycogloea tahitiensis is reported from Japan and additional undescribed taxa in the genus are briefly noted. Some characteristics of the genus are discussed, and a key is provided for six species recognized at this time.
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  • 52
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 40 (1999), S. 189-191 
    ISSN: 1618-2545
    Schlagwort(e): bamboo fungus ; hyperparasitism ; hyphomycetes ; mycoparasites ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Cryptophiale sphaerospora sp. nov. is described and illustrated based on a single collection attached to a synnematous fungus,Janetia synnematosa, from a dead bamboo culm. It differs from other species ofCryptophiala in having spherical to subspherical conidia and a cerebroid layer of phialides. The overall morohology of this species is smaller than that of previously described species.
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  • 53
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 198 (1995), S. 179-194 
    ISSN: 1615-6110
    Schlagwort(e): Fabaceae ; Vicia sect.Faba ; Electrophoresis ; seed albumins ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Electrophoretic analysis of seed albumins (PAGE) covered 173 accessions representing nine species ofVicia sect.Faba. The number of albumin bands recorded in particular species varied from three inV. eristaloides to 23 inV. faba; in total, 38 bands were distinguished in the investigated material. The examined species, exceptV. eristalioides, showed intraspecific variation with respect to the number and relative staining intensity of albumin bands; individual variation was especially marked inV. faba and inV. narbonensis. Hierarchical clustering of the investigated taxa was based onBhattacharyya distances calculated from the electrophoretic data. The taxa grouped in three main clusters.Vicia faba and the rather remotely relatedV. kalakhensis formed one cluster. The second cluster was composed ofV. narbonensis distantly related toV. hyaeniscyamus. The third cluster comprised three subgroups: 1.V. johannis, V. galilaea andV. serratifolia, 2.V. eristalioides, and 3.V. bithynica. The obtained results are discussed with reference to taxonomic relationships inVicia sect.Faba.
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  • 54
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 199 (1996), S. 109-120 
    ISSN: 1615-6110
    Schlagwort(e): Lamiaceae ; Scutellaria sect.Resinosa ; SEM ; nutlet sculpturing ; micromorphology ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Nutlet sculpturing of 22 taxa ofScutellaria sect.Resinosa, representing 18 of its 19 species, and the monotypic genusSalazaria was studied by scanning electron microscopy (SEM). The nutlets of sect.Resinosa, while remarkably variable among themselves, differed from hypothetically closely related sections in lacking circumferential banding and sessile glands. Species could be grouped by surface sculpturing into seemingly meaningful phenetic clusters.Scutellaria potosina var.platyphylla was sufficiently distinct micromorphically so as to be elevated to specific status asScutellaria platyphylla comb. and stat. nov. The significance of nutlet microcharacters within sect.Resinosa is discussed, especially as compared to closely related sections. The genusSalazaria had nutlet sculpturing quite different from all taxa belonging to sect.Resinosa.
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  • 55
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 199 (1996), S. 243-258 
    ISSN: 1615-6110
    Schlagwort(e): Eriocaulaceae ; Leiothrix crassifolia (L. nubigena, L. obtusifolia) ; Morphological and anatomical variation ; geographical differentiation ; taxonomy ; Flora of ‘campos rupestres’ ; Brazil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The morphological and anatomical leaf and scape differentiation ofLeiothrix crassifolia is analysed and classified into seven types (I, II, III, IV, V, VI, VII). The species has a relatively wide distribution in the campo rupestre of Minas Gerais in Brazil. Variation in the isolated populations on different mountain ranges is complex, does not follow a clear geographical pattern, and defies taxonomic classification.L. nubigena andL. obtusifolia are included inL. crassifolia.
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  • 56
    ISSN: 1615-6110
    Schlagwort(e): Rosaceae ; Rosa sect.Caninae ; Systematics ; taxonomy ; genetic variation ; hemisexual ; apomixis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Difficulties in delimiting well-defined entities in the dogroses (Rosa sect.Caninae) has resulted in very variable taxonomic treatments. The present study was undertaken to provide a background for taxonomy as well as plant breeding. Morphometric diversity was analysed on seedlings obtained from field collections in South Sweden of three species,Rosa dumalis, R. rubiginosa andR. villosa. A canonical variates analysis showed that the three species are relatively distinct whereas two subspecies ofR. dumalis were less well discriminated. Analyses of variance demonstrated that intraspecific variation is pronounced inR. dumalis and, to a lesser extent, inR. villosa.
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  • 57
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 205 (1997), S. 241-264 
    ISSN: 1615-6110
    Schlagwort(e): Boraginaceae ; Boragineae ; Anchusella ; A. variegata ; A. cretica ; Lycopsis ; Anchusa ; Mediterranean flora ; macromorphology ; micromorphology ; karyology ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The two closely related speciesLycopsis variegata andAnchusa cretica, formerly placed inAnchusa subg.Rivinia, were compared with the type species ofLycopsis andAnchusa, on the basis of a set of macro and microcharacters. The presence of only two fertile stamens as well as other peculiar characters in flower structure, androecium, gynoecium, pollen and fruit, supports the institution of the new genusAnchusella, consisting ofA. variegata andA. cretica. Karyological and eco-chorological aspects are consistent with morphological data in pointing to the autonomy of this genus, which appears characterized by autapomorphic, advanced traits.
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  • 58
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 208 (1997), S. 1-9 
    ISSN: 1615-6110
    Schlagwort(e): Fabaceae ; Vicia faba ; V. kalakhensis ; Seed albumins ; HPLC ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Previously reported electrophoretic seed albumin data have shown an unexpected association ofVicia faba withV. kalakhensis. In the present work, seed albumins ofV. faba (subsp.paucijuga and subsp.faba) were compared with those ofV. kalakhensis using ionexchange (IE) and reversed-phase (RP) high-performance liquid chromatography (HPLC). Two subspecies ofV. faba displayed similar seed albumin profiles. On the other hand, seed albumin profiles ofV. faba andV. kalakhensis showed no major protein peak in common either in IE-HPLC or RP-HPLC chromatograms. The reported differences in seed albumin composition ofV. faba andV. kalakhensis are consistent with other taxonomical data showingV. faba to be genetically distant from the wild relatives.
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  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 208 (1997), S. 239-248 
    ISSN: 1615-6110
    Schlagwort(e): Fabaceae ; Vicia ; sect.Hypechusa ; sect.Peregrinae ; Electrophoresis ; seed albumins ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract This work is a continuation of electrophoretic investigations aimed at revealing a wild relative ofVicia faba. Electrophoretic analysis (PAGE) of seed albumins covered 52 accessions representing eightVicia species of sect.Hypechusa and two species of sect.Peregrinae. Most of the examined species showed an intraspecific variation due to differences between accessions and/or individual variation within accessions. In spite of the intraspecific variation, marked interspecific differences were recorded. However, none of the investigated species displayed electrophoretic seed albumin patterns similar to those reported earlier forV. faba. Contribution of the obtained results to characterization of the examined taxa is discussed.
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  • 60
    ISSN: 1615-6110
    Schlagwort(e): Fabaceae ; Vicia faba ; trnL intron ; PCR-sequencing ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The chloroplasttrnL intron from 46 differentVicia accessions, representing five of the nine sections of the genusVicia subg.Vicia sensuMaxted (1991a) were amplified by the Polymerase Chain Reaction (PCR) using oligonucleotide primers homologous to conserved regions intrnL. The products fell into two distinct groups; those of approximately 250 nt and those of around 450 nt in length. Of these, products from 17 differentVicia species were cloned and their nucleotide sequences determined. Multiple alignments were assembled and phylogenetic trees constructed by the weighted least-squares distance method. ALathyrus latifolius trnL intron sequence was used as an outgroup. The resulting trees clearly group and separate the sectt.Narbonensis, Bithynica andFaba species but were less able to distinguish species from sectt.Hypechusa andPeregrinae. Based on these sequence data,V. faba appears to be more distant from sect.Narbonensis than sectt.Hypechusa andPeregrinae. The results are in general agreement with a recent treatment ofVicia subg.Vicia (Maxted 1993) and lend further support to placingV. faba in the monospecific sect.Faba.
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  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 213 (1998), S. 173-186 
    ISSN: 1615-6110
    Schlagwort(e): Fabaceae ; Vicia ; sect.Bithynicae ; sect.Narbonensis ; Allozymes ; genetic diversity ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Electrophoretic analysis of five enzyme systems, LAP, PGI, SKDH, SOD and 6-PGDH, among 102Vicia accessions representingV. bithynica and seven species of theV. narbonensis complex, namelyV. eristalioides, V. kalakhensis, V. johannis, V. galilaea, V. serratifolia, V. narbonensis andV. hyaeniscyamus, has been performed. The recorded variation was tentatively assigned to 41 allelic genes at eight loci; intraspecific variation was observed in all species except forV. eristalioides. The results obtained were compared with the corresponding data reported earlier forV. faba. Hierarchical grouping of the investigated taxa, includingV. faba, was based onNei's genetic identities calculated from the allozyme frequency data.Vicia faba andV. bithynica were shown to be most distantly related to one another and to the remaining species investigated.Vicia serratifolia appeared to be a peripheral member of theV. narbonensis complex. The results are discussed with reference to genetic diversity and taxonomic relationships of the species under study.
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  • 62
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 218 (1999), S. 179-192 
    ISSN: 1615-6110
    Schlagwort(e): Bryophyta ; Mitochondria ; nad5 gene ; group I intron ; molecular phylogeny ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In contrast to animals, the slowly evolving mitochondrial nucleotide sequences of plants appear well suited to investigate phylogenetic relations between old taxonomic groups. Analysis ofnad5 gene sequences in 47 bryophytes, the living representatives of very early land plants, confirm this assessment. Statistically reliable phylogenetic trees are obtained with different mathematical approaches. A group I intron sequence conserved in thenad5 gene of all 30 mosses and 15 liverworts investigated supports a sister group relationship of the two classes. The intron sequence adds phylogenetic information for fine resolution on top of the conserved exon sequences down to the level of classically defined orders or families, respectively. This intron is not present in the hornwortsAnthoceros husnotii andA. punctatus. The results allow statements on diverging taxonomic interpretations and support the monophyly of the liverworts, mosses, Jungermanniidae, Marchantiidae and Bryidae, and allow recognition of subclasses like Hypnanae and Dicrananae. Among the mosses, the derived orders (subclass Bryidae) are confidently set apart from the Sphagnales, Andreaeales, Polytrichales and Tetraphidales with Buxbaumiales occupying a mediating position. Among the liverworts, full support is found for the classic separation of simple (jungermanniid) and complex thalloid (marchantiid) species with a strikingly low mitochondrial sequence divergence among the latter.
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 40 (1995), S. 99-101 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; High temperature open-tubular columns ; Solvent make-up ; Acetophenone oxidation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Acetophnone, a substance stable at room temperature, is readily oxidizes in a high temperature open tubular liquid chromatographic system by the residual oxygen in the mobile phase. The oxidation product is less UV absorptive and detection sensitivity decreases greatly. To prevent the oxidation, through degassing of the mobile phase is necessary.
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  • 64
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Endotoxins ; Lipopolysaccharide ; Aminated poly(γ-methyl L-glutamate) ; Bovine serum albumin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A method is described for the selective removal of endotoxins from various protein solutions using columns packed with aminated poly (γ-methyl L-glutamate) (PMLG-NH2) spheres. The PMLG-NH2 adsorbents showed a high adsorbing activity for endotoxins which had an ionic strength of μ=0.05–1.0 and pH 5.0–9.0. The endotoxin-adsorbing capacity per millitre of the wet adsorbent increased from 0.40 to 1.35 mg (E. coli O111: B4 LPS) at μ=0.2 and pH 7.0 while the aminogroup content of the adsorbent increased from 0.8 to 3.5 meq g−1. The PMLG-NH2-3.5 has an amino-group content of 3.5 meq g−1. This column packing selectively adsorbed endotoxins, without loss of the protein, from a γ-globulin or cytochromec solution which contained endotoxins at μ=0.05 and pH 7.0. On the other hand, when bovine serum albumin (BSA) was present in solution with endotoxins, both the endotoxins and the BSA were adsorbed by the column. The BSA-adsorbing activity increased with increasing amino-group content of the adsorbent. However, this undesirable adsorption was suppressed with increasing ionic strength of the buffer. As a result, when the packing which had an amino-group content of 1.5 meg g−1 was used in conditions of μ=0.2 and pH 7.0, the endotoxins were removed from a BSA-containing solution without affecting the recovery of the BSA.
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  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 40 (1995), S. 51-57 
    ISSN: 1612-1112
    Schlagwort(e): Column electrophoresis ; Column liquid chromatography ; Phenolic lignin degradation compounds ; Sugar degradation products ; Quantitative analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A method for the quantitative analysis of phenolic lignin degradation products by capillary electrophoresis (CE) with on-column UV detection has been developed. The liquid biomass solutions contain low molecular hemicellulosic sugars and phenolic lignin degradation products with various degrees of polymerization. Special attention has been paid to the monomeric phenolic components of lignin degradation fragments, e.g. derivatives of phenolic acids, aldehydes, and alcohols. Uncoated fused silica capillaries and borate-phosphate buffer systems at moderate pH conditions were used in order to separate the compounds of interest. To provide validation of the method, the same samples were analyzed independently by HPLC using gradient elution on a RP-C18 column. As sugar degradation fragment, furan-2-carboxylic acid was detected.
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 40 (1995), S. 85-90 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Phenolic compounds ; Ion-pair solid phase extraction ; On-line trace enrichment
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Two packing materials, C18 and PLRP-S, are studied for on-line trace enrichment of phenolic compounds in water. Various precolumns of different internal diameter are also tested and the addition of an ion-pair reagent to increase retention and thus, breakthrough volumes of phenolic compounds, is studied. Best results are obtained when a PLRP-S precolumn is coupled on-line with a C18 analytical column and DAD detector. Addition of TBA considerably increases breakthrough volumes. In contrast, when a C18 precolumn is used, breakthrough volumes are lower and it is impossible to determine TCP and PCP, under the experimental conditions used, because of interference of other nonpolar compounds in the samples. The performance of the system is evaluated with river and tap water and the preconcentration of 10 ml of sample in a PLRP-S precolumn involves a linear range between 1 μg 1−1 and 20 μl−1 and limits of determination between 0.5 μg l−1 and 1 μg l−1 are obtained.
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  • 67
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 40 (1995), S. 631-637 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Trace analysis ; Pesticides in tap water ; Aromatic sulphonates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Methodology and instrumentation are described which allow chromatographic screening of water samples under substantially simplified conditions and at reduced cost. A single column is used to accomplish sample extraction, trace enrichment, and separation. The performance of such a system is demonstrated, and the results compared with conventionally used concepts.
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 40 (1995), S. 669-673 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Transchelation ; Zinc pyrithione and related compounds ; Antidandruff formulations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary An analytical procedure has been developed for the determination of zinc pyrithione in antidandruff formulations. Zinc pyrithione was converted into a stable copper complex and then analysed by reversed-phase HPLC. The proposed method allows the separation of the analyte from related pyrithiones and therefore is able to verify the compliance of cosmetic preparations with current legislation.
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  • 69
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Benzodiazepines ; Solvent effects ; ACN clusters
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Two different methods were used to determine the separation factor α at different temperatures and the Gibbs-Helmholtz parameters (Δ(ΔH), Δ(ΔS)) of two adjacent benzodiazepines on a chromatogram were obtained from plots of lnα versus 1/T. We first studied each factor (fraction of water ϕ in the ACN/water mixture and column temperatureT), which controls the retention mechanism, and then we examined the simultaneous variation of all these factors. The changes in Δ(ΔH) and Δ(ΔS) in relation to a volume fraction of water ϕ in an ACN/water mixture were examined. In the ACN/water system, Δ(ΔH) was fairly constant in the acetonitrile region of ϕ≤0.52 and appears to be a roughly linear function of ϕ for ϕ≥0.52. In this system Δ(ΔS) is approximately a parabolic function of ϕ with an optimum at ϕ≅0.52. The retention mechanism of ten benzodiazepines was found to be significantly different in the methanol/water and ACN/water mixtures. The separation optimization of these ten benzodiazepines was then considered. A fraction of water of 0.43 in the ACN/water mixture and a column temperature of 44°C gave the most efficient separation conditions in the ACN/water mixture.
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  • 70
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Polyurethane degradation products ; 2,4- and 2,6-toluendiamine ; Urine analysis ; Breast implants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A reversed-phase HPLC method has been developed for the urinary determination of mutagenic 2,4- and 2,6-toluendiamines. These amines are degradation products of polyurethane, a material used to cover textured silicone breast implants. FMOC-Cl was used as fluorescent derivatising agent in order to obtain a limit of detection of 15 ng/ml in urine. Pre-treatment of urine samples was by liquid/liquid extraction and urine specimens of patients after surgury were analysed.
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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 41 (1995), S. 657-660 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Polyphenols ; Flavonoids ; Phenolic acids and aldehydes ; Eucalyptus spp.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Standards of the polyphenols occurring in wood, bark and leaf extracts ofEucalyptus spp. (i.e. flavonoids and phenolic acids and aldehydes) have been analyzed by HPLC using reversed phase columns, gradient elution and diode-array detection. The conditions used are reported.
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  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 40 (1995), S. 657-661 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Reversed phases ; Polyencapsulated silica ; Polyacrylates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary By copolymerization of silica modified with vinyl groups and acrylic acid esters in suspension highly efficient, polymeric-encapsulated stationary-phases can be prepared. The suspending liquid has to be selected such that the monomers are at least partially adsorbed on the surface and the polymer formed does not precipitate. Under these conditions stationary phases capable of speedy mass transfer can be prepared, where the reduced plate heights are between 2 and 3. The silica surface shielding is optimized so that basic and acidic solutes elute with symmetrical peak.
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  • 73
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Chiral resolution of amino acids ; Pre-column derivatization ; Fluorescent chiral tagging reagents ; Stereochemical purity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Derivatization of amino acid enantiomers with fluorescent chiral Edman-type reagents, 4-(3-isothiocyanatopyrrolidin-1-yl)-7-nitro-2,1,3-benzoxadiazole [R(−)- and S(+)-NBD-PyNCS] and 4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole [R(−)-and S(+)-DBD-PyNCS], yields corresponding diastereomers separable by reversed-phase HPLC on normal achiral columns. The resolved diastereomers were detected fluorometrically at 530 nm with excitation at 490 nm for the NBD-PyNCS derivatives and at 560 nm with excitation at 450 nm for those derived from DBD-PyNCS reagents. This HPLC-derivatization method was used for evaluation of stereochemical purity for some synthetic commercial peptides. The enantioanalysis was reliable down to 0.05% racemization of the amino acid residues and a quantity of 100 μg peptide sample was usually enough for the analysis. Two acid hydrolysis methods, i.e. the standard procedure with constant-boiling hydrochloric acid (HCl) and a rapid vapor-phase procedure with HCl-trifluoroacetic acid (TFA) mixture, were compared. The later was found to be unsuitable owing to increased racemization of the amino acid residues during the hydrolysis. Judging from the results obtained for proline and leucine residues, most of the tested peptides including biologically active peptides, such as neurotensin, [d-Ala2,d-Leu5]-enkepharin and morphine tolerance peptide, possessed stereochemical purities higher than 98%. Influence of structural features of the peptides on the racemization of the amino acid residues was found to be significant.
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  • 74
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Mass spectrometric detection ; Fast atom bombardment ionization ; Serum bile acid ; Rat bile
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary In order to analyse bile acids in biological matrices, e.g. rat bile and human serum, high performance liquid chromatography (HPLC) was coupled to continuous-flow fast atom bombardment mass spectrometry (CFFAB-MS). A gradient elution system which had already proved to be well suited for the quantitative determination of conjugated bile acids in bile was modified to allow HPLC-CFFAB-MS-coupling. Due to the sensitivity of this coupling method it is possible to obtain more information about the biliary bile acid pattern and species-specific secondary bile acids. Furthermore, we were able to identify obviously unknown bile acid species in rat bile which most likely classify as mono-oxo and di-oxo-taurocholates (MW 513 Da, 511 Da) and mono-oxo-glycocholates (MW 463 Da). In the present study we show that using this system it is possible to determine both conjugated and unconjugated as well as sulfated bile acids, without time consuming group separation and derivatization, from rat bile and human serum. In addition, it is suggested that the method presented here should be considered for use in routine analysis.
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  • 75
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Fluorescence enhancement ; Bovine serum albumin ; Dansylamino acids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The effects of acetonitrile and bovine serum albumin (BSA) concentrations on the signal intensity and retention behavior of dansylamino acids have been examined by using γ-cyclodextrin-bonded silica gel as the stationary phase in microcolumn liquid chromatography. Fluorescence intensities of dansylamino acids were enhanced by BSA as a mobile phase additive, e.g., detection limits of dansyl derivatives of L-Ala and L-Phe were improved by a factor of 12–18.
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  • 76
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Micellar liquid phases ; Octanol-water partition coefficient ; Benzene and naphthalene derivatives
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary It is shown that the logarithm of the capacity factor (log k′) for fifteen benzene and naphthalene derivatives in micellar liquid chromatography with forty nine different mobile phases generally correlates better with the logarithm of the octanol-water partition coefficient (log Pow) than the capacity factor (k′). Optimum conditions are established to obtain the best linear correlations of log k′-log Pow.
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  • 77
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 40 (1995), S. 247-252 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Photolysis ; Electrochemical detection ; Drugs with chlorinated aromatic rings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Pharmaceuticals containing a thiazide ring or chlorinated aromatic ring were investigated with respect to enhanced selectivity in determination. Oxidative electrochemical detection coupled with HPLC was used to study the influence of the pH of the mobile phase under conditions of photolysis. To cover a pH range 3.9–12, the employment of a polymer column stable in alkaline media was necessary. The method offers the great advantage of derivatization without chemicals at low operating potentials, thereby providing high selectivity.
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  • 78
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 40 (1995), S. 296-302 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Structural isomer separation ; Cyclodextrin ; Polymers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Several β-cyclodextrin (CD)-bonded stationary phases for high performance liquid chromatography (HPLC) were prepared, based on silica beads coated with a poly(alkylamine), [poly(ethyleneimine)(PEI)]. In order to obtain stationary phases with a high content of CD and maximum accessibility of the CD cavity, the functionalization was carried out after the coating, using the mono-tosyl derivative of CD as the intermediate. The ability of these supports to separate ortho, meta and para isomers of some disubstituted benzene derivatives was examined. The contribution of the amino groups of the polymer and of the CD cavity to the separation process is discussed. The resolution is mainly based on the difference in the stability of the complexes of the various isomers with CD. The influence of the amount of CD on the height of the theoretical plate is also studied.
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  • 79
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Reversed phase ; Polystyrene ; Pellicular ; Ultra high molecular mass
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Ultra high molecular mass (〉 7 million dalton) polystyrenes are prone to degradation in size exclusion chromatography. In gradient elution reversed phase HPLC they do not elute visibly on small particle size porous supports. However, large diameter C18 pellicular particles were successfully employed for reversed phase study of ultra high molecular mass (15 million dalton) polystyrenes without polymer degradation during elution. Although retention for the lower molecular mass polystyrenes was lower than on small diameter porous particles, the medium high molecular mass polystyrenes (0.5–1 million dalton) showed similar retention. The addition of small diameter porous particles in small quantities, to the large diameter pellicular particles, increased the amount of retention of the low molecular mass polystyrenes without affecting the higher molecular mass polystyrenes.
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  • 80
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Methyl ethyl ketone in urine ; Derivatization ; 3-Methyl-2-benzothiazolinone hydrazone ; Comparison with GC-MS
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A HPLC method for the determination of methyl ethyl ketone (MEK) in urine after derivatization with 3-methyl-2-benzothiazolinone hydrazone is proposed. The calibration curve for the ketone was linear, ranging between 0.23–10 mg/L, with a detection limit of 0.025 mg/L. The results were compared to those obtained by GC-MS, coupled to the headspace technique. MEK derivatization and the derivative purification processes were verified with respect to the main variables such as reaction temperature, reagent concentration, probable interferences and enrichment phase. The method is simple and reliable and shows a good sensitivity.
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  • 81
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 40 (1995), S. 382-386 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Sulfonamides in foodstuffs ; Honey ; Milk ; Eggs
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A procedure for the simultaneous determination of several sulfonamides in different foods, such as honey, milk and eggs is proposed. The analysis is carried out using reversed phase liquid chromatography with spectrophotometric detection. Optimization of the mobile phase led to good separation and a short analysis time when an initial isocratic step with a 3∶97 acetonitrile: water mixture was used for 5 minutes, followed by a linear gradient up to a 40∶60 mixture over 15 min. The proposed method is suitable for routine quality control analysis to ensure the absence of sulfonamides in foods. Recovery studies yielded good results for all food samples because there were no interferences from the matrices.
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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 40 (1995), S. 411-416 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Particle beam LC/MS interface ; Capillary columns for LC ; Mycotoxins ; Peanut meal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A new method for the analysis of aflatoxins in food extracts, based on liquid chromatography/mass spectrometry interfacing, is presented. The chromatographic separation was performed with a reversed phase packed capillary column coupled with a modified particle beam interface capable of handling microliter per minute flow rates. This system allows higher overall sensitivity and easier operation procedures. The method has proved to be particularly suitable for the analysis of the toxins in very complex matrices. The specificity of electron impact ionization allowed positive identification of the aflatoxins with an excellent response linearity for accurate quantitation.
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  • 83
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Thin-layer chromatography ; Reversed phase ; 2-benzoylbenzoic acids ; Anionic and cationic counter ions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The 2-benzoylbenzoic acid series was investigated by reversed-phase, high-performance, thin-layer and column chromatography using various alkylammonium salts and di(2-ethylhexyl)orthophosphoric acid as polar associating reagents. The effects of the individual substituents on retention were quantified by Δlog k′ and ΔRM values. The compounds investigated differing in molecular structure (hydrophilic and hydrophobic substituents) commonly occurring groups in drugs and biologically active substances provide information on molecular interaction in these ion-pair systems. The combined effects on retention of organic modifier and ion-pair reagent concentration were investigated.
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  • 84
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Two-dimensional separation ; D- and L-amino acids ; Enantioseperation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A two-dimensional, column liquid chromatographic system is used for the determination of the D- and L-enantiomers of amino acids in biological samples. Separation of the amino acids is first on ion-exchange column by gradient elution with a sodium citratesodium chloride buffer. Enantioseparation is by subsequent injection of 3 μl heart-cuts of the individual amino acids onto a second column with a chiral crown ether stationary phase. Finally, fluorescence detection is after post-column labelling of the amino acids using ano-phthalaldehyde-2-mercaptoethanol reagent solution. The high separation power and selectivity of the system allow processing of complex samples with hardly any additional treatment and the determination of small quantities of D-amino acids in the presence of excess L-form. Applicability of the system is illustrated by the determination of D- and L-aspartate, serine, glutamate and alanine in various complex biological samples, such as protein hydrolysates, urine and biotechnological and food samples. Data are given on detectability, repeatability and linearity.
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 41 (1995), S. 43-50 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Ion pair LC ; Sweeteners, preservatives and antioxidants ; Food additive analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A paired-ion, reversed-phase high-performance liquid chromatographic method was developed for the simultaneous determination of sweeteners (dulcin, saccharin-Na and acesulfame-K), preservatives (sodium dehydroacetate, sorbic acid, salicyclic acid, benzoic acid, succinic acid, methyl-para-hydroxybenzoic acid, ethylpara-hydroxybenzoic acid, n-propyl-para-hydroxybenzoic acid, isopropyl-para-hydroxybenzoic acid, n-butyl-para-hydroxybenzoic acid, and isobutyl-para-hydroxybenzoic acid), and antioxidants (3-tertiary-butyl-4-hydroxyanisole and tertiary-butyl-hydroquinone). A mobile phase of acetonitrile-50 mM aqueous α-hydroxy-isobutyric acid solution (pH 4.5) (2.2 ∶ 3.4 or 2.4 ∶ 3.6, v/v) containing 2.5 mM hexadecyltrimethylammonium bromide and a C18 column with a flow rate at 1.0 mL/min and detection at 233 nm were used. This method was found to be very reproducible with detection limits ranged from 0.15 to 3.00 μg. The retention factor (k) of each additive could be affected by concentrations of hexadecyltrimethylammonium bromide and α-hydroxyisobutyric acid, and pH and ratio of mobile phase. The presence of additives in some food samples was determined.
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  • 86
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Limit of detection ; Precision ; Uncertainty prediction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The precision of integration over noisy instrumental output for quantitative analysis is studied. A probability theory is developed to predict the relative standard deviation (RSD) of integration results over an integration domain from one-point integation (peak height measurement) to entire area integration in HPLC. Common integration modes of horizontal zero line and oblique zero line are taken into account, but no peak overlap is assumed. The question of the analytical superiority of peak height measurement or integration for quantitation is answered. In the HPLC apparatus used, the minimum RSD of measurements is found in the integration domain of ca. ±0.5 σ for analytes [peaks are approximated by the Gaussian signal of width, σ (standard deviation)]. The RSD of integration measurements is also shown to depend on the stochastic properties of back-ground noise (uncorrelated noise and correlated 1/f type noise). The theoretical conclusion is verified by Monte Carlo simulation and HPLC experiments for some aromatic compounds.
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  • 87
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Ion-pair and GPC separations ; Amoxicillin oligomers ; β-Lactam ring polymers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Polymeric substances formed from concentrated sodium amoxicillin in an aqueous solution have been separated using two high-performance liquid chromatographic methods. We used a C18 reversed-phase column with tetrabutylammonium chloride as an ion-pairing agent with an acetonitrile gradient and a TSKgel G2500PWxl column with water as the solvent for gel permeation chromatography. The separated materials, ranging in size from the monomer to the tetramer, have been characterized by functional-group chemical analysis, while the identification of the piperazine-2,5-dione was done using a pure standard. A greater number of peaks which were also better defined were obtained using the ion-pair reversed-phase method, and open and closed beta-lactam ring polymer forms could be distinguished. Using the gel permeation method, only a few monomer, piperazine-2,5-dione, dimer, trimer and combined amoxicillin trimer and tetramer peaks were obtained with water, although those obtained were quite well defined. The data on the time-course of formation of the oligomers and the amoxicillin degradation product were virtually identical by both methods.
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  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Chromatographia 41 (1995), S. 148-152 
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; On-column fluorimetric detection ; Gradient elution ; Dansyl amino acids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Fluorimetric detection in the presence of a stationary phase has been applied to gradient elution of dansyl amino acids in liquid chromatography. A 1.5 mm ID quartz tube packed with the same materials as the separation column was employed for the flow cell. Conventional-size columns were employed. The peak height of analytes increased with increasing retention owing to focusing and environmental effects of the stationary phase, leading to improvements in sensitivity, which was pronounced for analytes eluting late. The lower the gradient, the larger the improvement in sensitivity achieved. Detection limits were improved by a factor of up to 5.1 by fluorimetric detection using the packed flow cell, compared with those achieved using a common empty flow cell.
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  • 89
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; LC-MS ; Cinchona alkaloids ; New column packing materials
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A major problem in the HPLC analysis of alkaloids is the poor peak shape and consequently low resolution, due to the interactions of the basic alkaloids with the residual acidic silanol groups of most reversed phase materials. The performance of new packing materials specially designed for the separation of basic compounds has been studied using mobile phases without the special additives commonly applied in the analysis of alkaloids. Strongly basic Cinchona alkaloids were used as test compounds. Retention characteristics and selectivities of each material were studied, after mobile phase optimisation for the column. The influence of the major factors (nature and content of the organic modifier, pH value, salt concentration) affecting resolution was studied. The mobile phases were chosen so that they could be used in thermospray LC-MS. The addition of salts to the mobile phase improves separation but in general the modification of the mobile phase gave little change in selectivity. The performance of silicabased C18 material proved superior to the polymer materials tested.
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  • 90
    Digitale Medien
    Digitale Medien
    Springer
    Journal of applied phycology 11 (1999), S. 411-419 
    ISSN: 1573-5176
    Schlagwort(e): Bangiales ; Porphyra life history ; culture ; conchocelis ; conchosporangia ; spores ; neutral conchospores morphology ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Since 1992, as part of a study to circumscribe the genus Porphyra in New Zealand, an extensive culture programme has been developed at the Museum of New Zealand Te Papa Tongarewa. This collection currently houses more than 800 cultures and 150strains. We currently recognise at least 20 species in New Zealand, most of which are undescribed. Close observation of reproduction and the development of conchocelis-phase filaments grown in the laboratory, under controlled conditions of temperature, irradiance and photoperiod, has enabled the recognition of characters that can assist in species separation. The comparative taxonomic value of a range of such characters is discussed, including reporting a novel reproductive mode.
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  • 91
    Digitale Medien
    Digitale Medien
    Springer
    Journal of applied phycology 11 (1999), S. 429-436 
    ISSN: 1573-5176
    Schlagwort(e): distribution ; harvesting ; Porphyra ; recruitment ; seasonality ; South Africa ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Although Porphyra is commercially farmed in many countries, in South Africa only small harvests of wild populations for sale as nori have been carried out. The discovery that Porphyra improves growth of South African abalone (Haliotis midae) farmed inland-based tanks has led to increased pressure to harvest wild populations. This paper reports on a survey of the distribution and seasonality of Porphyra in the southern Western Cape. Porphyrawas present at all sites surveyed, and showed considerable temporal variation. A significant amount of the Porphyra present is in reserves and therefore protected from harvesting. Close rexamination of one site revealed seasonal populations of Porphyra that occupied different niches dependent on season. Recruitment peaked in spring and autumn, leading to dense summer and winter populations. Summer populations generally grew lower in the eulittoral than winter populations. No pattern in the mortality of larger thalli wasde tected, though sporeling mortality was high following recruitment peaks. Although it seems that most sites in the southern Western Cape are suitable for harvesting, the taxonomy of the genus in the region urgently needs revision if populations are to be appropriately managed.
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  • 92
    Digitale Medien
    Digitale Medien
    Springer
    Journal of applied phycology 10 (1998), S. 573-580 
    ISSN: 1573-5176
    Schlagwort(e): Dunaliella ; ITS ; PCR ; RFLP ; strains ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genus Dunaliella comprises 28 species defined primarily by morphological and physiological criteria, which vary considerably depending on growth conditions. Concomitantly, the taxonomic status of various species is uncertain. To confirm the taxonomic identity and to better understand the relationship within Dunaliella, seven taxa ( D. salina, D. bardawil, D. tertiolecta, D. parva, D. viridis, D. lateralis, D. peircei) were compared using RFLP analysis of the nuclear rDNA repeats, specifically the internal transcribed spacer regions, including the 5.8S rRNA gene. Volvox aureus was used as an outgroup. A single ITS PCR amplification product was obtained for each taxon. An ITS fragment of ca. 640 bp was present in all the taxa within the subgenus Dunaliella, except for D. salina CCMP 1303 (ca. 540 bp) and D. lateralis (subgenus Pascheria) (ca. 600 bp). A cluster analysis based on the presence or absence of bands generated by digestion of the PCR product with 8 restriction endonucleases (DpnI, HhaI, EcoRI, PvuII, TaqI, HaeIII, MspI, StyI) revealed no correlation between the genetic relationship inferred from the ITS-RFLP data and the morpho-physiological attributes used for taxonomy. In addition, differences in morphology, physiology and in the length and restriction fragment patterns of the ITS region of D. salina CCMP 1303 suggest that this strain does not belong to Dunaliella.
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  • 93
    Digitale Medien
    Digitale Medien
    Springer
    Biodiversity and conservation 4 (1995), S. 183-205 
    ISSN: 1572-9710
    Schlagwort(e): biological collections ; conservation ; biodiversity information ; phylogenetic systematics ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Systematics and taxonomy are essential: they respectively elucidate life's history, and organize and verify biological knowledge. This knowledge is built of interrelated concepts which are ultimately accounted for by biological specimens. Such knowledge is essential to decide how much and what biodiversity survives human onslaughts. The preservation of specimens in natural history collections is the essential part of the process which builds and maintains biological knowledge. These collections and the human expertise essential to interpret specimens are the taxonomic resources which maintain accurate and verifiable concepts of biological entities. Present and future knowledge of the complexities and diversity of the biosphere depends on the integrity of taxonomic resources, vet widespread ignorance and disregard for their fundamental value has created a global crisis. Preservation of specimens in natural history collections is chronically neglected and support to study and manage collections is very insufficient. The knowledge held by experienced taxonomists is not being passed on to younger recruits. Neglect of collections has destroyed countless specimens and threatens millions more. These threats to taxonomic resources not only impinge on systematics but all biology: this tragedy jeopardizes the integrity of biological knowledge. The consequences for environmental conservation and therefore humanity are also of dire severity and the biodiversity crisis adds unprecedented weight to the barely recognized crisis in taxonomy and systematics.
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 37 (1996), S. 367-369 
    ISSN: 1618-2545
    Schlagwort(e): Dematiaceae ; Deuteromycotina ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sporidesmium filiferum isolated from a leaflet ofPhellodendron amurense lying on the soil surface at Tsukuba, Japan is described together with photomicrographs.
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  • 95
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 39 (1998), S. 333-335 
    ISSN: 1618-2545
    Schlagwort(e): Cortinarius prunicola ; Cortinarius Sect.Sericeocybe ; new species ; Rosaceae ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Cortinarius prunicola sp. nov., found in orchards and plantations ofPrunus mume, is described and illustrated. It is characterized by its dry and violet-white carpophores, unpleasant odor, and its close association withP. mume in spring and early summer. The differences betweenC. prunicola and similar species are briefly discussed.
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  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 40 (1999), S. 165-183 
    ISSN: 1618-2545
    Schlagwort(e): freshwater fungi ; Halosphaeriaceae ; taxonomy ; tropics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The generic concepts inAniptodera, Halosarpheia, Nais andPhaeonectriella are discussed and those species occurring in freshwater are described, some with illustrations. Five new species:Aniptodera lignicola, A. mauritaniensis, A. megalospora, A. palmicola, Phaeonectriella appendiculata are also described. A key to the freshwater species in the above genera and a synoptic diagram of their ascospores are provided.
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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 40 (1999), S. 317-320 
    ISSN: 1618-2545
    Schlagwort(e): Ascomycota ; marine fungi ; new species ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new speciesDactylospora mangrovei is described and illustrated and compared withD. haliotrepha andD. canariensis, all marine inhabiting species.Dactylospora haliotrepha andD. mangrovei are tropical/sub-tropical mangrove species collected in Hong Kong, Malaysia, Taiwan and Thailand, whileD. canariensis was described from temperate waters. A map of the geographical distribution of the three marineDactylospora species is presented.
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Mycoscience 40 (1999), S. 185-188 
    ISSN: 1618-2545
    Schlagwort(e): Amphisphaeria ; ascomycetes ; bamboo fungi ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new species ofArecophila and a species previously known asAmphisphaeria coronata are described and illustrated from dead culms of bamboo.Arecophila bambusae sp. nov. is distinct in the genus in having ellipsoidal ascospores with slightly round ends, and asci with a narrow subapical ring.Arecophila coronata comb. nov. has asci with a wedgeshaped apical ring and weakly striated ascospores enclosed in wide mucilaginous sheath.
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  • 99
    Digitale Medien
    Digitale Medien
    Springer
    Biology and philosophy 10 (1995), S. 223-228 
    ISSN: 1572-8404
    Schlagwort(e): Clade ; class ; definition ; defining property ; individual ; intension ; name ; organism ; ostensive definition ; species ; taxon ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Materialart: Digitale Medien
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  • 100
    Digitale Medien
    Digitale Medien
    Springer
    Biodiversity and conservation 5 (1996), S. 1295-1305 
    ISSN: 1572-9710
    Schlagwort(e): Archaea ; Bacteria ; Antarctica ; biodiversity ; 16S rRNA ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Prokaryotes perform key functions in Antarctic ecosystems, and knowledge of the taxonomy of Antarctic prokaryotes is a prerequisite for the transfer of information between fields of scientific inquiry. The taxonomy of prokaryotes has been greatly revised and improved due to the refinements afforded by molecular techniques such as 16S rRNA sequencing. Past inventories of Antarctic microbial diversity are difficult to reconcile with the developing, phylogenetically-based taxonomy. Antarctic prokaryotes are considerably diverse and most evolutionary groups are represented, including representatives of both Archaea and Bacteria. The diversity appears unique due to the ease with which new species can be isolated; however, that may be a result of our vastly incomplete knowledge of both Antarctic and non-Antarctic prokaryotic diversity. Use of the 16S rRNA gene as a molecular clock would suggest that the majority of Antarctic prokaryotes diverged from their nearest known non-Antarctic relatives long before a stable ice-sheet developed in Antarctica. The time of colonization (or recolonization) of Antarctic environments by individual species may have been very recent in evolutionary time scales.
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