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
    Chrom (1923)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 63 (1923), S. 413-416 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01470137
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    facet.materialart.
    Unknown
    Chrom (1923)
    Springer
    Details
    Publication Date: 1923-10-01
    Print ISSN: 1618-2642
    Electronic ISSN: 1618-2650
    Topics: Chemistry and Pharmacology
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    Electronic Resource
    Electronic Resource
    Beeinflussung des Stoffwechsels der Schilddrüsenhormone bei defizitärer bis subtoxischer Selenversorgung (1995)
    Springer
    European journal of nutrition 34 (1995), S. 277-283 
    Details
    ISSN: 1436-6215
    Keywords: Selen ; Glutathion-Peroxidase ; Schilddrüsenhormone ; Thyroxin ; Triiodthyronin ; Typ-I-Deiodase ; Selenium ; glutathione peroxidase ; thyroid hormones ; thyroxine ; triiodothyronine ; type-I-deiodinase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary In an experiment with 72 male weanling Sprague Dawley rats the effect of varying selenium intake on parameters of thyroid hormone metabolism was investigated. The animals were divided into 6 groups. One of the groups was fed a semi-synthetic diet based on casein which was poor in selenium (38 µg/kg). The other groups were fed the same diet supplemented with Na2SO3·5H2O to achieve a selenium concentration of 50, 100, 300, 600 and 3 000 µg/kg. The experiment lasted 40 days. Different selenium intake had no effect on food intake, weight gain, hematological and selected clinical-chemical parameters. Determination of glutathione peroxidase activity and selenium concentration of serum showed a selenium deficiency in animals fed the diet not supplemented with selenium. Serum T3 concentration and hepatic type-I-deiodinase activity were decreased in the group without selenium supplementation in contrast to the groups fed diets adequate in selenium (100, 300 µg/kg). A diet supplementation of 50 µg/kg already increased hepatic type-I-deiodinase activity to levels of the groups fed diets adequate in selenium. In groups supplemented with 600 and 3 000 µg/kg diet, serum T3 concentration was reduced by half of groups fed diets adequate in selenium. Supplementation with 3 000 µg Se/kg lowered the type-I-deiodinase activity in contrast to groups fed diets adequate in selenium, but not significantly. Serum concentrations of T4 and fT4 were not changed by various selenium intake. The results of this investigation show an alteration in thyroid hormone metabolism at low selenium intake as well as at high selenium intake.
    Notes: Zusammenfassung Die Auswirkungen einer unterschiedlichen Selenversorgung auf Parameter des Stoffwechsels der Schilddrüsenhormone sollten in einem Versuch mit 72 männlichen wachsenden Sprague Dawley Ratten untersucht werden. Die Tiere wurden in 6 Gruppen eingeteilt, wovon eine Gruppe eine selenarme halbsynthetische Diät auf Caseinbasis mit einem Se-Gehalt von 38 µg/kg erhielt. Die übrigen Gruppen erhielten die selbe Diät, die durch Zulage von Na2SO3·5H2O auf Selengehalte von 50, 100, 300, 600 und 3 000 µg/kg gebracht wurde. Die Versuchsdauer betrug 40 Tage. Die unterschiedliche Zufuhr von Selen hatte keinen Einfluß auf Futteraufnahme, Entwicklung der Lebendmasse, hämatologische und ausgewählte klinisch-chemische Parameter. Ein Selenmangel bei der Gruppe, die die nicht supplementierte Basisdiät erhalten hatte, konnte anhand der Aktivität der Glutathion-Peroxidase und der Selenkonzentration im Serum diagnostiziert werden. Beide Parameter stiegen ab einer Se-Zulage von 300 µg/kg noch an, allerdings geringfügig. Die Konzentration von T3 im Serum und die Aktivität der Typ-I-Deiodase in der Leber der Gruppe ohne Selenzulage war im Vergleich zu den bedarfsgerecht (100, 300 µg/kg) versorgten Gruppen vermindert. Bereits eine Selenzulage von 50 µg/kg Diät konnte die Aktivität der Typ-I-Deiodase auf die Werte der bedarfsgerecht versorgten Gruppen mit 100 und 300 µg Selenzulage anheben. Bei den Gruppen mit 600 und 3 000 µg/kg Diät Selenzulage war die Konzentration von T3 im Serum im Vergleich zu den bedarfsgerecht versorgten Gruppen auf etwa die Hälfte reduziert. Durch die Selenzulage von 3 000 µg/kg Diät war die Aktivität der Typ-I-Deiodase gegenüber den bedarfsgerecht versorgten Gruppen vermindert, die Verminderung war jedoch nicht statistisch signifikant. Die Konzentrationen von T4 und fT4 waren durch die unterschiedliche Selenzufuhr kaum verändert. Die Untersuchung zeigt insgesamt, daß sowohl unzureichende als auch über den Bedarf hinausgehende Selenzufuhr zu Veränderungen im Stoffwechsel der Schilddrüsenhormone führt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01625339
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Zum Einfluß des isoenergetischen Austausches von Stärke durch Olivenöl und Fischöl auf die Konzentrationen der Lipide in Plasma und Lipoproteinfraktionen beim Schwein (1994)
    Springer
    European journal of nutrition 33 (1994), S. 286-298 
    Details
    ISSN: 1436-6215
    Keywords: Plasmalipide ; Lipoproteine ; Fischöl ; Olivenöl ; Schwein ; Plasma lipids ; lipoproteins ; fish oil ; olive oil ; pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Two experiments with sows were performed to investigate the effect of isoenergetic replacement of starch by fish oil or olive oil on concentrations of lipids in plasma and lipoproteins. The first experiment was based on a cross-over design with three periods, each lasting 16 days. Each sow was fed during one of the periods a basal ration with isoenergetic addition of (1) starch (495 g/d), (2) olive oil (221 g/d), or (3) fish oil (223 g/d) based on energetic requirement for maintainance. The second experiment was based on a cross-over design with eight periods, each lasting 16 days. In the first and in the last periods, each sow was fed the basal ration. In the other six periods, each sow was fed the basal ration with addition of two different amounts of (1) starch (284/568 g/d), (2) olive oil (140/281 g/d), or (3) fish oil (141/282 g/d). The two different amounts of addition were selected to exceed the energetic requirement for maintainance by 25 % or 50 %. In both experiments blood samples were taken before each change of the ration. In both experiments olive oil elevated the concentration of cholesterol in plasma in comparison with starch. This elevation was due to a large elevation in high-density lipoproteins (HDL), and a slight elevation in low-density lipoproteins (LDL) and very-low density lipoproteins (VLDL). The ratio between HDL and LDL cholesterol was increased by feeding olive oil. The effect of olive oil on concentrations of cholesterol in plasma and lipoproteins was dose-dependent. In both experiments none of the two dietary oils significantly changed concentrations of triglycerides in plasma and lipoproteins. Concentrations of phospholipids in plasma, HDL, and LDL were elevated by olive oil. In both experiments addition of fish oil elevated concentration of cholesterol in plasma due to elevated cholesterol concentration in LDL. Concentration of HDL cholesterol was not changed by fish oil. Thus, the ratio between HDL cholesterol and LDL cholesterol was lowered by fish oil. The effect of fish oil on concentration of cholesterol in plasma and lipoproteins was also dose-dependent. Fish oil had no significant effect on phospholipid concentrations in plasma and lipoproteins. In conclusion, in the present experiment olive oil caused antiatherogenic changes of the lipoprotein profile, whereas fish oil caused proatherogenic changes of the lipoprotein profile.
    Notes: Zusammenfassung Es wurden zwei Versuche mit Sauen durchgeführt, um die Wirkung des isoenergetischen Austausches von Stärke durch Fischöl und Olivenöl auf die Konzentration der Lipide im Plasma und in den Lipoproteinen zu untersuchen. Im ersten Versuch erhielten 9 nichtgravide Sauen in einem Cross-over Design mit 3 Versuchsperioden jeweils 16 Tage lang eine Grundration plus isoenergetischer Zulage an (I) Stärke (495 g/Tag), (II) Olivenöl (221 g/Tag) und (III) Fischöl (223 g/Tag) auf energetischem Erhaltungsniveau. Im zweiten Versuch erhielten 8 nichtgravide Sauen in einem Cross-over Design mit 8 Versuchsperioden jeweils 16 Tage lang eine Grundration auf energetischem Erhaltungsniveau plus zwei Zulagestufen an (I) Stärke (284 bzw. 568 g/Tag), (II) Olivenöl (140 bzw. 281 g/Tag) und (III) Fischöl (141 bzw. 282 g/Tag). Die beiden Zulagestufen waren so gewählt, daß der energetische Erhaltungsbedarf um 25 % bzw. 50 % überschritten wurde. In der ersten und der letzten Versuchsperiode wurde jeweils nur die Grundration gefüttert. In beiden Versuchen wurden unmittelbar vor jeder Umstellung der Versuchsration Blutproben entnommen. Olivenöl erhöhte in beiden Versuchen im Vergleich zur isoenergetischen Stärkeration die Konzentration des Cholesterins im Plasma, basierend auf einem starken Anstieg in den high-density Lipoproteinen (HDL) und einem mäßigen Anstieg in den low-density Lipoproteinen (LDL) und den very low-density Lipoproteinen (VLDL). Der Quotient aus HDL- und LDL-Cholesterin wurde durch Olivenölzulage erhöht. Die Konzentration der Triglyceride wurde in beiden Versuchen durch die beiden Öle nicht signifikant beeinflußt. Die Konzentration der Phospholipide wurde durch Olivenöl im Plasma sowie in den HDL und den LDL erhöht. Die Wirkung des Olivenöls auf die Konzentrationen von Cholesterin und Phospholipiden in Plasma und Lipoproteinen war dosisabhängig. Fischölzulage erhöhte im Vergleich zur isoenergetischen Stärkeration die Cholesterinkonzentration im Plasma, basierend auf einem Anstieg in den LDL. Die Konzentration des Cholesterins in der HDL-Fraktion änderte sich nicht, so daß unter Fischölzulage ein vermindertes Verhältnis zwischen HDL- und LDL-Cholesterin auftrat. Die Wirkung des Fischöls auf die Konzentrationen von Cholesterin in Plasma und Lipoproteinen war ebenfalls dosisabhängig. Fischölzulage hatte keinen signifikanten Einfluß auf die Konzentrationen der Phospholipide im Plasma und in den Lipoproteinen. Insgesamt führte unter den gewählten Versuchsbedingungen der Ersatz der Stärke durch Olivenöl zu einer antiatherogen Verschiebung des Lipoproteinprofils, Fischöl hingegen zu einer proatherogenen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01614434
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Concentrations of thyroid hormones in serum and activity of hepatic 5′ monodeiodinase in copper-deficient rats (1996)
    Springer
    European journal of nutrition 35 (1996), S. 288-291 
    Details
    ISSN: 1436-6215
    Keywords: Copper deficiency ; rat ; thyroxine ; triiodothyronine ; 5′Monodeiodinase ; Kupfermangel ; Ratte ; Thyroxin ; Triiodthyronin ; 5′Monodeiodase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Ziel der vorliegenden Arbeit war es, den Einfluß von Kupfermangel auf den Stoffwechsel der Schilddrüsenhormone bei der Ratte zu untersuchen. Dazu wurde ein Versuch mit männlichen wachsenden Sprague-Dawley-Ratten durchgeführt. Der Versuch beinhaltete zwei Gruppen, die entweder eine Kupfermangeldiät (0,06 mg Cu/kg) oder eine Kontrolldiät (16 mg Cu/kg) erhielten. Die Ratten beider Gruppen erhielten dabei durch ein Pair-feeding Regime identische Futtermengen. Die Tiere der Kupfermangelgruppe waren zu Versuchsende um 5 % leichter als die der Kontrollgruppe. Die Kupfermangeltiere hatten darüber hinaus eine stark verminderte Aktivität des Ceruloplasmins im Serum (um 97 %) sowie veränderte hämatologische Parameter, was einen starken Kupfermangel bei diesen Tieren belegte. Zur Abschätzung des Stoffwechsels der Schilddrüsenhormone wurden die Konzentrationen des gesamten und des freien Thyroxins (T4) und des Triiodthyronins (T3) im Serum sowie die Aktivität der 5′ Monodeiodase (5′D) in der Leber bestimmt. Die Kupfermangeltiere hatten eine erhöhte Konzentration an T3 im Serum, während sowohl die Konzentration an freiem und am gesamten T4 als auch die Aktivität der 5′D in der Leber nicht verändert waren. Insgesamt zeigt die vorliegende Untersuchung, daß auch sehr starker Kupfermangel nur geringfügige Änderungen des Stoffwechsels der Schilddrüsenhormone bei wachsenden Ratten verursacht.
    Notes: Summary The aim of the present study was to investigate the effect of copper deficiency on thyroid hormone metabolism in rats. Therefore, an experiment with growing male Sprague-Dawley rats was carried out, consisting of two groups of rats fed either a copper-deficient (0.06 mg Cu/kg) or a copper-adequate diet (16 mg Cu/kg). Both groups of rats were fed identical quantities of diet by pair-feeding. Copper deficiency decreased the final body weight of the rats by 5 % compared to copper-adequate control rats. A severe copper-deficient state in the rats fed the copper-deficient diet was proved by a large decrease of ceruloplasmin activity in serum (by 97 %) and hematological changes. For estimation of thyroid hormone metabolism, the concentrations of total and free thyroxine (T4) and triiodothyronine (T3) in serum and the activity of hepatic 5′ monodeiodinase (5′D) were determined. Copper-deficient rats had an increased concentration of T3 in serum, whereas the concentrations of total and free T4 as well as the activity of hepatic 5′D were not different compared with copper-adequate control rats. Therefore, the study shows that copper deficiency has only slight effects on thyroid hormone metabolism in growing rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01625694
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Chronic vitamin E inadequacy and thermally treated oils affect the synthesis of hepatic metallothionein isoforms (2000)
    Springer
    European journal of nutrition 39 (2000), S. 112-120 
    Details
    ISSN: 1436-6215
    Keywords: Key words Vitamin E inadequacy – thermally treated soybean oil – metallothionein isoforms – liver – rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Notes: Summary Background: Metallothionein (MT)# synthesis can be stimulated in many organs not only by various metals such as cadmium, zinc, and copper, but also by many nonmetalic compounds or experimental conditions such as oxidative stress. The latter lead to the hypothesis that MT is induced in response to free radicals formed in tissues and lipid peroxidation. Aims of the study: Whether the relationship between lipid peroxidation amd MT synthesis is a common phenomenon also valid for lipid peroxidation induced by dietary factors such as chronic vitamin E inadequacy and autoxidation products of polyenoic fatty acids derived from thermally oxidized oil was investigated in the presence study. Methods: The relationship between the induction of metallothionein isoforms I and II (MT-I and MT-II) in response to diet-induced lipid peroxidation using a rat model system in which lipid peroxidation was examined in vivo by chronic vitamin E inadequacy or by administration of lipid peroxidation products from a thermally treated polyenoicrich oil with either basal (dietary zinc concentration: 48 mg/kd; experiment 1) or Zn-stimulated MT levels (dietary zinc concentration: 305 mg/kd; experiment 2) was studied. In both experiments, growing male rats were fed diet containing either a fresh or a thermally treated soybean oil with deficient of sufficient amounts of vitamin E (14 and 11 vs. 648 and 560 mg α-tocopherol equivalents per kg diet) over 40 days according to a bifactorial experimental design. Plasma and liver concentrations of tocopherols and hepatic levels of thiobarbituric acid-reacitve substances (TBARS) were measured by high performance liquid chromatography. MT isoform concentrations in rat liver were isolated and quantified by ion-exchange high performance liquid chromatography and atomic absorption spectrometry. Results: Irrespective of the zinc supply, rats receiving inadequate amounts of vitamin E with the diet had markedly lower plasma and liver concentrations of α-tocopherol and total tocopherols than vitamin E-sufficient rats. ANOVA also revealed an interaction between the diet factors vitamin E and oil on tocopherols in plasma and liver of rats from both experiments. In experiment 1, where rats received normal amounts of dietary zinc, ingestion of the thermally treated oil impaired the tocopherol status compared to the treatment with the fresh oil, although this effect was only obvious in the vitamin E-deficient groups. In experiment 2, where rats received excessive amounts of zinc, the thermally treated oil did not contribute to a reduction of the tocopherol status in plasma and liver. In both experiments a significant increase in TBARS level, indicative of lipid peroxidation, was observed in the liver at chronic vitamin E inadequacy, but no effect of the oil was observed. Here, we show that the dietary treatment had some effects on the synthesis of liver metallothionein isoforms. In groups, receiving normal amounts of zinc, there was a significant interaction between the dietary treatments on the levels of MT-I and MT-II in liver. Chronic vitamin E inadequacy which was accompanied by diminisched tocopherol levels in liver induced the synthesis of MT-I and MT-II. When vitamin E inadequacy was combined with the ingestion of a thermally treated polyenoic acid-rich oil hepatic levels of MT-I and MT-II remained low. In experiment 2, where rats were fed the high zinc diet, vitamin E inadequacy caused an increase of hepatic MT-I level just as in experiment 1, although this MT stimulating effect was irrespective of the oil. For MT-II there was a 43% increase in the vitamin E-deficient group fed the fresh oil compared to all the other groups, although this effect was not statistically significant. The liver MT isoform response to stress was similar in rats with basal MT levels and Zn-induced liver MT levels. The failing effect of the thermally treated oil on MT levels which were stimulated by vitamin E deficiency in experiment 2 was possibly due to the low oxidation grade of the thermally treated oil. Conclusion: The present results are strongly indicative of an apparent induction of MT isoform synthesis in response to an impaired antioxidant defence system in the lipid regions of liver cells induced by vitamin E inadequacy. In contrast, thermally treated polyenoic-rich oils with a certain oxidation grade seem to restrain the induction of MT isoform synthesis under the present experimental conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003940070027
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Zum Einfluß von Zinkdepletion auf Fettgehalt und Fettsäurezusammensetzung von Leber und Gehirn bei zwangsernährten Ratten (1993)
    Springer
    European journal of nutrition 32 (1993), S. 187-197 
    Details
    ISSN: 1436-6215
    Keywords: Zinkdepletion ; Zwangsernährung ; Fettgehalt ; Fettsäurezusammensetzung ; Leber ; Gehirn ; Zinc deficiency ; force-feeding technique ; fat content ; fatty acid composition ; liver ; brain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary In the present work the influence of zinc deficiency on fat content and fatty acid composition of liver and fatty acid composition of brain of rats with a high food intake was investigated. Using the force-feeding technique the rats were fed 14.5 g food daily at days 1 to 4, and then 11.6 g food for later days. After 7 days the zinc-deficient animals had a fatty liver which was characterized by an increase in fat content (68%) and dry matter (23%). The amounts of lauric acid, myristic acid, myristoleic acid, palmitic acid, palmitoleic acid, and oleic acid were also increased by 100 to 200% in the liver of zinc-deficient animals, whereas the amount of arachidonic acid was decreased by 29%. The amounts of phosphatidylcholine and phosphatidylethanolamine in the liver were not changed by zinc deficiency, but the fatty acid composition of these phospholipids was changed. The liver phospholipids of zinc-deficient animals had a decreased proportion of arachidonic acid, but an increased proportion of docosahexaenoic acid. In the zinc-deficient animals there also existed a positive correlation between the fat content in the liver and the ratio between linoleic and arachidonic acid in the liver and a negative correlation between the fat content in the liver and the amount of arachidonic acid in the liver. These correlations as well as the changes in liver fatty acid composition of zinc-deficient animals suggest that the fatty liver might be the result of a disturbed metabolism of linoleic acid. In contrast, zinc deficiency did not influence the fatty acid composition of brain. This means that brain is protected against the effects of short-term zinc deficiency.
    Notes: Zusammenfassung In der vorliegenden Arbeit wurde der Einfluß von Zinkdepletion auf den Gesamtfettgehalt und die Fettsäurezusammensetzung der Leber sowie die Fettsäurezusammensetzung des Gehirns bei Ratten mit sehr hoher Futteraufnahme untersucht. Mit Hilfe der Zwangsernährung erhielten die Tiere in den ersten vier Versuchstagen täglich 14,5 g Futter und in den folgenden Tagen 11.6 g Futter. Es zeigte sich, daß die Depletionstiere bereits nach 7 Versuchstagen eine Fettleber entwickelt hatten, die durch einen um 68% erhöhten Gesamtfettgehalt und einen um 23% erhöhten Trockensubstanzgehalt gekennzeichnet war. Zugleich waren in der Leber der Depletionstiere die Gehalte der Laurinsäure, Myristinsäure, Myristoleinsäure, Palmitinsäure, Palmitoleinsäure und Ölsäure um 100 bis 200% erhöht, während der Gehalt der Arachidonsäure um 29% erniedrigt war. Die Gehalte der Phospholipide Phosphatidylcholin und Phosphatidylethanolamin waren bei den Depletionstieren im Vergleich zu den Kontrolltieren unverändert, jedoch zeigten sich Änderungen der Fettsäurezusammensetzung dieser Phospholipide, gekennzeichnet vor allem durch einen verminderten Anteil an Arachidonsäure (20:4) und einen erhöhten Anteil an Docosahexaensäure (22:6). Neben diesen Effekten bestand zwischen dem Gesamtfettgehalt der Leber und dem Quotienten aus Linolsäure und Arachidonsäure in der Leber bei den Depletionstieren eine positive Korrelation, zwischen dem Gesamtfettgehalt der Leber und dem Arachidonsäuregehalt der Leber eine negative Korrelation. Diese Korrelationen sowie die geänderte Fettsäurezusammensetzung in der Leber deuten darauf hin, daß die Fettleber Folge des im Zinkmangel gestörten Linolsäurestoffwechsels sein könnte. Im Gegensatz zur Leber traten im Gehirn keine Veränderungen der Fettsäurezusammensetzung sowie der Fettsäuregehalte auf. Dies deutet darauf hin, daß das Gehirn zumindest kurzfristig gegen Auswirkungen des Zinkmangels geschützt ist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01610729
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Temperature Feedback and Collagen Cross-Linking in Argon Laser Vascular Welding (1998)
    Springer
    Lasers in medical science 13 (1998), S. 98-105 
    Details
    ISSN: 1435-604X
    Keywords: Keywords: Collagen; Infrared thermometry; Radiometry; Temperature; Tissue fusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract. A preliminary single-animal study of in vivo argon laser vascular welding was conducted using a canine model. The effects of temperature feedback control and saline drip cooling on patency and collagen cross-linking were investigated. The surface temperature at the centre of the laser spot was monitored using a two-colour infrared thermometer. The surface temperature was limited by either a saline drip or feedback control of the laser. Acute patency was evaluated and collagen cross-link assays were performed. Though both protocols yielded successful tissue fusion, welds maintained at a surface temperature of 50°C using feedback control had an elevated cross-link count compared to controls, whereas tissues irradiated without feedback control experienced a cross-link decrease. Simulations using the LATIS (LAser-TISsue) computer code suggest that drip-cooled procedures achieve significantly higher temperatures beneath the tissue surface than temperature feedback-controlled procedures. Differences between the volumetric heating associated with drip-cooled and feedback-controlled protocols may account for the different effects on collagen cross-links. Covalent mechanisms may play a role in argon laser vascular fusion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101030050061
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Morphogenesis of potato plants in vitro. II. Endogenous levels, distribution, and metabolism of IAA and cytokinins (1994)
    Springer
    Journal of plant growth regulation 13 (1994), S. 147-152 
    Details
    ISSN: 1435-8107
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The levels of endogenous IAA and cytokinins (zeatin, zeatin riboside, isopentenyladenine, and isopentenyladenosine) were determined in potato plants cultured in vitro under red light (R) and blue light (B) on medium with or without hormones. On medium without hormones in B, plants contained much higher cytokinin levels, particularly in leaves and roots, and also slightly elevated IAA levels. Kinetin in the medium in B changed the distribution of cytokinins and significantly increased IAA level in roots. In R, the presence of kinetin led to an increased cytokinin level in the whole plant, while the IAA level was slightly lower. IAA in the medium in B decreased cytokinin level in all plant parts, while the IAA level did not change significantly. In R, the presence of IAA in the medium led to a moderate increase of CK level and to a significant increase in IAA level, especially in roots. Uptake of 1-14C-IAA and of 3H-zeatin was generally higher in B than in R. Higher percentage of IAA taken up in B was converted to conjugates in the roots. Metabolism of 3H-zeatin was similar in R and B with only slight differences in metabolite amounts. Thus, in all experimental situations in which tuber formation was stimulated, IAA level in roots and stolons rose significantly, stressing the importance of an IAA gradient for tuber formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00196379
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Über das Schicksal von Randpopulationen der Großtrappe(Otis tarda L.) in Niederösterreich (1977)
    Springer
    Journal of ornithology 118 (1977), S. 93-105 
    Details
    ISSN: 1439-0361
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary 1. General tendencies in the Middle European status ofOtis tarda are discussed. Bustards tend to form small isolated populations near the border to main distribution areas. 2. It is suggested to divide populations into those of 1., 2. and 3. order from the center of distribution to the peripheral areas (P1, P2, P3). 3. The development of five P3 groups of Lower Austrian bustards show the destructive impact of economical projects (e.g. highways, powerlines, pipelines) upon the peripheral populations which cause their final extinction. 4. Out of five peripheral populations known in 1968, four have disappeared until 1975. Total numbers of bustards living in P3 groups declined from about 42–59 in 1968 to 27 in early 1975. That means a loss of about 36,7 to 55,2%. 5. The still existing peripheral P3 (Sitzendorf/Goggendorf) shows in general a good development but is recently endangered by a road project which will divide the traditional area into two parts. This may lead to the same development as in the other P3. 6. The development of the P2 Marchfeld is discussed. The slight increase from 1973/74 is considered to be the result of bustard invasions out of threatened peripheral P3 in Lower Austria. The further existence of the Marchfeld population is therefore highly endangered. Since 1942 up to early 1975 this group declined about 79%.
    Notes: Zusammenfassung 1. Die allgemeine Bestandsentwicklung vonOtis tarda im mitteleuropäischen Verbreitungsgebiet wird diskutiert mit dem Ergebnis, daß augenblicklich eine Tendenz zu inselartiger Abtrennung kleinerer Populationen von den Hauptverbreitungsgebieten besteht. 2. Zur besseren Kennzeichnung der Populationen wird vorgeschlagen, bei Trappenpopulationen von Hauptverbreitungsarealen ausgehend Populationen 1., 2. und 3. Ordnung zu unterscheiden (P1, P2, P3). 3. Am Beispiel von fünf niederösterreichischen Randpopulationen wird aufgezeigt, in welcher Weise technische Einrichtungen die Randpopulationen gefährden und schließlich deren Verschwinden bewirken. 4. Von fünf Randpopulationen (P3), die 1968 bekannt waren, gab es im Frühjahr 1975 noch eine. Zwei weitere sind am Erlöschen. Die derzeit noch intakte P3 Stizendorf/Goggendorf wird durch ein Straßenprojekt bedroht. 5. In der P2 Marchfeld geht der jüngst ausgewiesene Bestandszuwachs zulasten der verlöschenden Randpopulationen. Für die weitere Existenz der Marchfeld-Population sind die Zukunftsaussichten ungünstig. Der Rückgang in dieser P2 beträgt seit 1942 ca. 79%. Die Zahl der in P3-Gruppen lebenden Trappen verminderte sich seit 1968 bis heute von 42–59 auf 27 Exemplare.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01647361
    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...