ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Calmodulin-like activity in a mineralising tissue: The rat molar tooth germ (1981)
    Springer
    Calcified tissue international 33 (1981), S. 545-548 
    Details
    ISSN: 1432-0827
    Keywords: calmodulin ; calcium ; mineralisation ; tooth germ
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Calmodulin, a calcium binding protein, has been implicated in the regulation of many calcium-dependent biological processes. Since calcium has an important role in hard tissue genesis, both at intra- and extracellular levels, we anticipate that calcium binding proteins may modulate this process. The present study investigated a mineralising tissue, the rat molar tooth germ, to determine the presence of calmodulin-like activity. A heat-treated cell-free extract of tooth germs provided enhancement of Ca2+-dependent Mg2+-ATPase and 3′:5′-nucleotide phosphodiesterase activity. No enhancement occurred in the absence of calcium or in the presence of trifluoperazine. SDS-polyacrylamide gel electrophoresis of this extract revealed a protein band of approximately 18,000 mol. wt. These findings indicate the presence of calmodulin-like activity in rat molar tooth germs and support the proposal that calcium and calcium binding proteins, in particular calmodulin, have a major regulatory role in the biology of mineralising tissues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02409487
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Reproduction and development of the South American freshwater stingrays,Potamotrygon circularis and P. motoro (1983)
    Springer
    Environmental biology of fishes 9 (1983), S. 3-24 
    Details
    ISSN: 1573-5133
    Keywords: Amazonia ; Batoidea ; Brazil ; Captive breeding ; Chondrichthyes ; Colombia ; Elasmobranchii ; Freshwater adaptation ; Growth rate ; Potamotrygonidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Observations of reproductive features and body measurements were made on wild-caught, freshwater stingrays, Potamotrygon circularis and P. motoro, from the Amazon drainage of western Brazil and southern Colombia. Further observations were made in Detroit's Belle Isle Aquarium on a captive pair of P. motoro and their descendants, which constitute the first known captive breeding colony of potamotrygonids. The gross structure and function of female and male reproductive systems are described. There is no obvious difference between those of the two species. They are aplacentally viviparous, the young being nourished in advanced stages by uterine milk secreted by trophonemata. Size at onset and completion of sexual maturation, breeding season and behavior, gestation period, litter size and sex ratios are discussed. Up to 21 proportional measurements were made on several fetal and postnatal stages of both species. Several proportional changes occur in very early fetal life, but most body proportions undergo only minor changes from advanced fetal through adult stages. A growth curve is proposed for P. motoro based on observations of the captive colony.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00001055
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Life history implications of a tagging study of the largetooth sawfish, Pristis perotteti, in the Lake Nicaragua-Río San Juan system (1982)
    Springer
    Environmental biology of fishes 7 (1982), S. 207-228 
    Details
    ISSN: 1573-5133
    Keywords: Batoids ; Chondrichthyes ; Costa Rica ; Elasmobranchs ; Euryhalinity ; Freshwater adaptation ; Growth rate ; Isolation of population ; Nicaragua
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Of a total of 377 Pristis perotteti tagged in the Lake Nicaragua-Río San Juan System, 214 (56.8% were recovered. Eighty were recovered at the original tagging site; four moved downstream the full length of the river; and 127 tagged at the source of the river were recovered in all parts of the lake. Only one was recovered in a different river system, 58 km down the coast from the main mouth of the Río San Juan. A life span of 30 years is suggested, with rapid growth (30–40 cm per year) in the first three years, slowing to about 4 or 5 cm per year in the later years of life. Maximum sizes collected were 384 cm for males, 429 cm for females, smaller than maximum lengths reported elsewhere. The lake sawfish are not physically landlocked, but individuals remain in fresh water for very long periods; parturition takes place in fresh water; all sizes are found in the lake; and it appears that this stock finds all of its ecological needs met in the lake. Individuals may spend all of their lives in fresh water, although, as a species, P. perotteti has not completely abandoned the sea, since some are known to occur in salt water. The Lake Nicaragua-Río San Juan sawfish are a discrete stock, with only limited gene flow with neighboring stocks. P. perotteti is farther along in its adaptation to fresh water, in being able both to osmoregulate and reproduce there, than other known euryhaline elasmobranchs, except for the African stingray, Dasyatis garouaensis, of the Niger-Benue System, and the completely adapted South American freshwater rays (family Potamotrygonidae).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002497
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Root elongation in saline solution related to calcium binding to root cell plasma membranes (1997)
    Springer
    Plant and soil 191 (1997), S. 67-76 
    Details
    ISSN: 1573-5036
    Keywords: calcium ; plasma membrane ; root elongation ; salinity ; sodium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract To gain a better understanding of the relations between root elongation and the amount of Ca2+ bound to the plasma membrane (PM), melon plants were grown in aerated solutions containing different concentrations of CaCl2 with various concentrations of NaCl or mannitol. With increasing external concentrations of NaCl or mannitol, root elongation was suppressed. Addition of CaCl2 to the external medium alleviated the inhibition of root elongation by high concentrations of Na+, but not of mannitol. Root elongation in media containing high concentrations of NaCl was correlated with the computed amount of Ca2+ bound to the PM. A model describing relative root elongation (RRL) under salt stress was developed. This model takes into account the osmotic potential in the growing solution (based on the mannitol experiments) and the computed amount of Ca2+ bound to the PM. Calcium binding was calculated by applying a Gouy-Chapman-Stern sorption model using the same parameters deduced from studies on PM vesicles. This model combines electrostatic theory with competitive binding at the PM surface. The model for RRL allowed the computation of a critical value for the fraction of negative sites binding Ca2+ on the PM needed for nearly optimal (95%) root elongation. Any decrease below this critical value decreased the RRL. Root elongation of Honey Dew (salt-resistant cv.) was greater than that of Eshkolit Ha'Amaqim (salt-sensitive cv.) under NaCl stress. Nearly optimal root growth for Honey Dew and Eshkolit Ha'Amaqim occurred when 40% and 51% of total membrane charged sites were bound by Ca2+, respectively. The effect of osmotic potential on the suppression of root elongation was the same for the two cultivars. To our knowledge, this report provides the first fully quantitative estimates of PM-bound Ca2+ relative to salt toxicity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004241506347
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    N-Methyl-N-Diäthoxyphosphorylamideo-Dervite des Hexachlorocyclotriphosphazatriens. II. Die Ammonolyse der N-Methyl-N-deäthoxyphosphorylamido-chlorcocyclotriphosphazatriene (1975)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 416 (1975), S. 169-173 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N-Methyl-N-Diethoxyphosphorylamido Derivatives of Hexachlorocyclotriphosphazatriene. II. Ammonoloyses of N-Methyl-N-Diethoxyphosphorylamido-ChlorocyclotriphosphazatrienesMonokis-[N-methyl-N-diethroxyphosphorylamido]-pentachloro-cyclotriphospha-zatriene and 2, 4-bis-[N-methyl-N-diethoxyphosphorylamido]-2, 4, 6, 6-tetrachloro-cyclotriphosphazatriene react with gaseous ammonia at room temperature to the corresponding diamino compounds, N3P3CL4-n[NCH3P(O)(OC2H5)2]n(NH2)2, (n = 1, 2). Total Exchange of the chlorine in the N-Methyl-Ndiethoxyphosphorylamido-derivatives, N3P3CL6-n[NCH3P(O)(OC2H5)2]n, (n = a, 2, 3), takes place during the reaction with liquid ammonia. Aminophosphazenes of the type N3P3[NCH3P(O)(OC2H5)2]n(NH2)6-n, (n = 1, 2, 3), are formed. The described aminocyclotriphosphazatrienes are characterized by their melting points, elementary analyses, molecular weights and the TLC-Rf-values.
    Notes: Monokis-[N-methyl-N-diäthoxyphorylamido]-pentachloro-cyclotriphosphazatrien und 2, 4-Bis-[N-methyl-N-diäthoxyphosphorylamido]-2,4,6,6-tetrachlorocyclotriphosphazatrien reagieren mit gasförmigem Ammoniak bei Raumtemperatur zu den entsprechenden diaminoverbindungen, N3P3CL4-n[NCH3P(O)(OC2H5)2]n(NH2)2, (n = 1, 2). Vollständiger Austausch des Chlors in den N-Methyl-N-diäthoxyphosphorylamido-Derivaten, S3P3CL6-n[NCH3P(O). (OC2H5)2]n, (n = 1, 2, 3). findet bei der Umsetzung mit flüssigem ammonial Statt. Es werden dabei Aminocyclophosphazene des Typs N3P[NCH33P(O)(OC2H5)2]n(NH2)6-n, (n = 1. 2. 3) gebildet, Die beschriebenen Aminocyclophosphazatriene werden durch ihre Schmelzpunkte, Elementaranalysen, Molmassen und die dünnschichtchromatographischen Rf-Werte charakterisiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19754160208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    N-Methyl-N-diäthoxyphosphorylamido-Derivate des Hexachlorocyclotriphosphazatriens. III. NMR-spektroskopische Untersuchungen zur Konstitution der N-Methyl-N-diäthoxyphosphorylamido-chloro-cyclotriphosphazatriene (1975)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 418 (1975), S. 171-178 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N.M.R. Spectroscopic Investigations of N-Methyl-N-diethoxyphosphorylamido-chloro-cyclotriphosphazatrienesThe high resolution 31P-n.m.r. spectroscopy provides essential informations about the molecular structure of N-methyl-N-diethoxyphosphorylamido derivatives of the hexachlorocyclotriphosphazatriene. Whereas the compound N3P3Cl4[NCH3P(O)(OC2H5)2]2 possesses nongeminal structure, are the substituents in the compound N3P3Cl3[NCH3P(O)(OC2H5)2]3 geminally arranged. The calculated 31P spectra agrees closely with the observed.The interpretation of the 1H-n.m.r. spectra corresponds with that of the 31P-n.m.r. spectra.
    Notes: Die hochauflösende 31P-NMR-Spektroskopie liefert wesentliche Informationen über die Molekülstruktur von N-Methyl-N-diäthoxyphosphorylamido-Derivaten des Hexachlorocyclotriphosphazatriens. Während die Verbindung N3P3Cl4[NCH3P(O)(OC2H5)2]2 nichtgeminale Struktur besitzt, erweist sich die Verbindung N3P3Cl3[NCH3P(O)(OC2H5)2]3 als geminales Substitutionsprodukt. Die berechneten 31P-Spektren stimmen gut mit den experimentellen überein.Die Aussagen aus den 1H-NMR-Spektren stehen mit denen aus den 31P-NMR-Spektren in Einklang.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19754180213
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    NMR-spektroskopische Untersuchungen an Mercaptophosphazenen. I. Verlauf der Reaktion von Natriumethylmercaptid mit Hexachlorocyclotriphosphazatrien bzw. Octachlorocyclotetraphosphazatetraen (1979)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 448 (1979), S. 100-106 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N.M.R. Spectroscopic Investigations of Thiophosphazenes. I. Reactions of Sodium Ethylthiolate with Hexachlorocyclotriphosphazatriene and OctachlorocyclotetraphosphazatetraeneBy reactions of hexachlorocyclotriphosphazatriene with an excess of sodium ethylthiolate as a suspension in ether all of the possible geminal derivatives N3P3Cl6-n(SEt)n; n = 1-6, are formed in different quantities. Products from reactions of octachlorocyclotetraphosphazatetraene with sodium ethylthiolate, N4P4Cl8-n(SEt)n, likewise contain all of the geminally substituted derivatives up to n = 8 with the exception of the derivatives with n = 1 and n = 7. Compounds with n = 3, 4, or 5 exist in two geminal isomers respectively. Nongeminal ethylthiochlorophosphazenes were not found by any reaction. The formed compounds were isolated by chromatographic methods and studied by 31P n.m.r. spectroscopy.
    Notes: Bei Umsetzungen von Hexachlorocyclotriphosphazatrien mit einem Überschuß an Natriumethylmercaptid in etherischer Suspension entstehen in unterschiedlichen Mengen alle denkbaren geminalen Substitutionsprodukte N3P3Cl6-n(SEt)n; n = 1-6. Im Reaktionsprodukt des Octachlorocyclotetraphosphazatetraens mit Natriumethylmercaptid, N4P4Cl8-n(SEt)n, lassen sich außer den Verbindungen mit n = 1 und n = 7 ebenfalls alle geminalen Substitutionsprodukte biz zu n = 8 nachweisen, wobei sich für die Verbindungen mit n = 3, 4, 5 jeweils beide geminalen Isomeren bilden. Nichtgeminale Mercaptochlorophosphazene waren bei keiner Umsetzung nachweisbar. Die entstandenen Verbindungen wurden säulenchromatographisch isoliert und 31P-NMR-spektroskopisch untersucht.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19794480111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    NMR-spektroskopische Untersuchungen an Mercaptophosphazenen. II. NMR-spektroskopische Untersuchungen an 15N-markierten Mercaptophosphazenen (1979)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 448 (1979), S. 107-114 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N.M.R. Spectroscopic Investigations of Thiophosphazenes. II. N.M.R. Spectroscopic Investigations of 15N Labelled ThiophosphazenesCompletely 15N labelled compounds of the type 15N3P3Cl6-n(SR)n, R = Et or Ph; n = 0, 2, 4, or 6, and of the type 15N4P4Cl8-n(SR)n, R = Et; n = 0, 4, or 8, were prepared and investigated by means of both 31P n.m.r. spectroscopy and 15N n.m.r. spectroscopy respectively. The coupling constants 2JPP, in some cases only found by simulating the spectra, and the coupling constants 1JPN are given. The values of these coupling constants and their relation are discussed. The general tendency is visible, that with increasing coupling constant 1JPN the coupling constant 2JPP decreases. With increasing grade of substitution n the 15N chemical shifts are changed to higher fields.
    Notes: Vollständig 15N-markierte Verbindungen des Typs 15N3P3Cl6-n(SR)n, R = Et, Ph; n = 0, 2, 4, 6, und des Typs 15N4P4Cl8-n(SR)n, R = Et; n = 0, 4, 8, wurden synthetisiert und mit Hilfe der 31P-NMR-Spektroskopie und der 15N-NMR-Spektroskopie untersucht. Die Kopplungskonstanten 2Jpp, die in einigen Fällen nur auf dem Wege der Spektrensimulation gefunden werden, sowie die Kopplungskonstanten 1JPN werden angegeben und ihre jeweilige Änderung und ihr Verhältnis zueinander diskutiert. Es wird die allgemeine Tendenz sichtbar, daß bei zunehmender Kopplungskonstante 1JPN die Kopplungskonstante 2JPP abnimmt. Mit zunehmendem Substitutions-grad n ändern sich die 15N-chemischen Verschiebungen nach höherem Feld.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19794480112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Untersuchungen zur Temperaturabhängigkeit der 31P-chemischen Verschiebung in Trialkoxyphosphazen-N-phosphoryldialkylesternProfessor Hans-Albert Lehmann zum 60. Geburtstage am 1. Mai 1979 gewidmet (1979)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 451 (1979), S. 5-11 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Temperature Dependence Investigations of 31P Chemical Shifts of Trialkoxyphosphazene N-phosphoryldialkylestersThe 31P NMR spectra of a series of trialkoxyphosphazene-N-phosphoryldialkylesters, (RO)3P=N—P(O)(OR′)2, where R = R′ = Et; R = Et, R′ = Bu; R = Bu, R′ = Et; R = R′ = Bu; and R = R = R′ = Hex respectively, and of trichlorophosphazene-N-phosphoryldichloride were investigated at various temperatures. The temperature dependence of chemical shift of phosphorus belonging to the phosphazene group is multiplicately larger than that of phosphorus belonging to the phosphoryl group. This fact also could be confirmed for other simple phosphazene and phosphoryl compounds. As discussed this different temperature dependence of 31P chemical shift is not a consequence of the medium but of the molecular structure.
    Notes: Für eine Reihe von Trialkoxyphosphazen-N-phosphoryldialkylestern, (PO)3P=N—P(O)(OR′)2, wobei R = R′ = Et; R = Et, R′ = Bu; R = Bu, R′ = Et; R = R′ = Bu bzw. R = R′ = Hex waren, sowie für Trichlorphosphazen-N-phosphoryldichlorid wurden jeweils 31P-NMR-Spektren bei verschiedenen Temperaturen aufgenommen. Es zeigte sich, daß die Temperaturabhängigkeit der chemischen Verschiebung für den Phosphor der Phosphazen-Gruppierung um ein mehrfaches größer ist als die für den Phosphor der Phosphoryl-Gruppierung. Dies konnte auch allgemein für andere einfache Phosphazen- und Phosphoryl-Verbindungen bestätigt werden. Es wird diskutiert. daß diese unterschiedliche Temperaturabhängigkeit der 31P-chemischen Verschiebung nicht auf Medieneinflüsse, sondern auf die molekulare Struktur zurückzuführen ist.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19794510102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    NMR-spektroskopische Untersuchungen an 15N-markierten N-Phosphorylphosphazenen und Imidodiphosphorsäure-DerivatenProfessor Hans-Albert Lehmann zum 65. Geburtstage am 1. Mai 1984 gewidmet (1984)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 511 (1984), S. 7-18 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N.M.R. Spectroscopic Studies of 15N Labelled N-Phosphorylphosphazenes and Imidodiphosphoric Acid Derivatives15N labelled compounds were prepared and investigated by means of 31P- and 15N-NMR spectroscopy. The chemical shift values δP and δN, and the coupling constants 1JPN and 2JPP are discussed and interpreted qualitatively by semiempirical quantumchemical calculations (CNDO/2) using POPLE'S ΔE-model.
    Notes: 15N-markierte Verbindungen der Substitutionsreihen wurden synthetisiert und mit Hilfe der 31P- und 15N-NMR-Spektroskopie untersucht. Die chemischen Verschiebungen δP und δN sowie die Kopplungskonstanten 1JPN und 2JPP werden diskutiert und qualitativ mit Hilfe halbempirischer quantenchemischer Rechnungen (CNDO/2) im Rahmen des POPLE-schen ΔE-Modells interpretiert.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19845110402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...