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  • 1
    ISSN: 1432-1440
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary The measurements of pCO2 in human blood with the Astrup microequipment and with a quickly recording CO2-electrode were compared. The CO2-electrode has a very small space, filled with a solution of 0,001 mol NaHCO3, near the surface of a pH glas electrode. The sample of blood is separated from this space by a 12 µ Teflon-membrane, permitting a diffusion of CO2 into the buffer solution. There pH is altered proportional to log pCO2 according to the reaction CO2+H2O=H2CO3=H++HCO 3 − . Measurements were made using the same sample. The difference between the results (m=+1,44±0.6 mm Hg pCO2) was caused by a difference in temperature (measurement with the Astrup microequipment at 38° C, with the CO2-electrode at 37° C). Double measurements with each apparatus had the following results: standard error μ=±0.46 mm Hg pCO2 with the Astrup microequipment, μ=±0.06 mm Hg pCO2 with the CO2-electrode (range 12 to 60 mm Hg pCO2).
    Notizen: Zusammenfassung Es wird über vergleichende Untersuchungen mit einer schnellanzeigenden CO2-Elektrode und der Astrupschen Mikro-pH-Elektrode bei der Bestimmung des Kohlensäurepartialdruckes im menschlichen Blut berichtet. Das Charakteristicum der CO2-Elektrode ist ein an die pH-empfindliche Membran der Glaselektrode angrenzender, auf einen schmalen Flüssigkeitsraum beschränkter Reaktionsraum, der mit 0,001 mol. Natriumbicarbonatlösung gefüllt ist. In ihn hinein kann durch eine Teflon-Membran aus dem angrenzenden Blut CO2 diffundieren, das durch entsprechende Reaktion mit der Bicarbonatlösung nach der Gleichung CO2+H2O=H2CO3=H++HCO 3 − das pH als vom log pCO2 linear abhängige Größe ändert. Die mittlere Abweichung für die Bestimmung des Kohlensäurepartialdruckes aus jeweils denselben Blutproben wurde mitm=+1,44±0,6 mm Hg pCO2 bestimmt. Er ist auf die Temperaturdifferenz von 1° C in beiden Meßanordnungen zurückzuführen. Bei Doppelanalysen mit jeweils der gleichen Meßordnung betrug der mittlere Fehler des Mittelwertes bei der Methode nachAstrup ±0,46 mm Hg pCO2, bei der beschriebenen CO2-Elektrode ±0,06 mm Hg pCO2 für den geprüften Bereich von 12–60 mm Hg pCO2.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular medicine 51 (1973), S. 1033-1042 
    ISSN: 1432-1440
    Schlagwort(e): Hemodynamic abnormalities in cirrhosis ; venous admixture in cirrhosis ; circulatory changes in cirrhosis ; arterial unsaturation in cirrhosis ; pulmonary arteriovenous shunts in cirrhosis ; O2 dissociation curve in cirrhosis ; Hämodynamik bei Lebercirrhose ; venöse Beimischung ; intrapulmonale Shunts bei Lebercirrhose ; arterielle Untersättigung bei Lebercirrhose ; O2-Dissoziationskurve bei Lebercirrhose
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Lebercirrhose ist häufig mit zirkulatorischen sowie respiratorischen Veränderungen vergesellschaftet. Die auffälligsten Befunde dabei sind 1. Gefäßveränderungen der Haut 2. Zunahme der peripheren Durchblutung 3. Reduktion des peripheren Widerstandes 4. Verkürzung der Zirkulationszeit 5. erhöhtes Blutvolumen 6. Zunahme des Herzminutenvolumens 7. Hyperventilation 8. O2-Untersättigung des arteriellen Blutes. Für die arterielle Untersättigung wurde u.a. eine Zunahme der venösen Beimischung infolge von intrapulmonalen Shunts verantwortlich gemacht. Die Ursache für das Auftreten intrapulmonaler Kurzschlußverbindungen konnte bisher nicht eindeutig geklärt werden. Es wurden vaso-aktive Substanzen dafür verantwortlich gemacht, die jedoch bisher nicht näher identifiziert werden konnten. Eigene Untersuchungen zeigten, daß es bei Patienten mit Lebercirrhose durch intravenöse Applikation von Histamin zu einer statistisch signifikanten Zunahme der venösen Beimischung kam, während diese Zunahme bei einem Kontrollkollektiv nicht nachweisbar war. Auch andere bei Patienten mit Lebercirrhose vorhandene Abnormalitäten der Zirkulation konnten durch Histamin modellhaft nachgeahmt bzw. verstärkt werden.
    Notizen: Summary Cirrhosis of the liver is frequently accompanied by circulatory and respiratory changes. Among the main pathological modifications one finds: (1) vascular changes of the skin, (2) increased peripheral blood flow, (3) reduced vascular resistance, (4) shortened circulation time, (5) increased blood volume, (6) increased cardiac output, (7) hyperventilation, (8) arterial unsaturation. Some investigations make it probable that the arterial unsaturation is caused by intrapulmonary shunts. The cause of decreased vascular resistance, vaso-dilatation and arterial-venous shunts has not been sufficiently clarified. Theoretically, the most probable explanation is that a unidentified vasoactive material is responsible. This could be histamine, bradykinin or any other substance with might be less metabolized in the diseased liver or in the lung. In own investigations the intrapulmonary shunt volume of venous admixture during histamine infusion was measured in patients with cirrhosis and in controls. In normals the venous admixture was 4.5% of the cardiac output before and 5.1% during histamine administration and in cirrhotics 12.4% before and 17.2% with histamine administration. Besides, a considerable increase in cardiac output and the lowering of peripheral resistance during histamine administration show that an already existing tendency to increased blood flow may very easily be intensified in cirrhotic patients. Thus the available evidence from this model indicates that a vasodilator substance probably affects the vascular system of these patients at various sites.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1432-1793
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  The structure of a benthic microbial food web and its seasonal changes were studied in the shallow brackish waters of the island of Hiddensee, northeastern Germany, at two sites in close proximity by monthly or bimonthly sampling from July 1995 to June 1996. Abundance and biomass of phototrophic and non-phototrophic bacteria, heterotrophic flagellates (HF) and ciliates as well as the biomass of microphytobenthos were determined in the upper 0.3 cm sediment layer. Abundance of organisms showed strong positive correlation with water temperature, with the exception of the bacteria. Non-phototrophic bacterial numbers ranged from 7 × 108 to 6.7 × 109 cells cm−3 and phototrophic bacterial abundance from 4 × 107 to 2.7 × 108. Heterotrophic protist abundance ranged from 8 × 103 to 104 × 103 ind cm−3 for HF and from 39 to 747 ind cm−3 for ciliates. The biomass partitioning demonstrated the primary importance of non-phototrophic bacteria (min. 0.83, max. 84.87 μg C cm−3), followed by the microphytobenthos (min. 1.32, max. 50.93 μg C cm−3). The heterotrophic protists contributed roughly the same fraction to the total microbial biomass, with the biomass of the HF being slightly higher (HF 0.23 to 1.76 μg C cm−3, ciliates 0.04 to 1.17 μg C cm−3). Taxonomic classification of the benthic HF revealed the euglenids to be the most important group in terms of abundance and biomass, followed by thaumatomastigids and kinetoplastids. Other important groups were apusomonads, cercomonads, pedinellids and cryptomonads. The structure of the HF assemblage showed strong seasonal changes with euglenids being the most abundant taxa in summer, while apusomonads and thaumatomastigids were predominant in winter. Similar to the pelagic microbial food web, benthic picophototrophic bacteria were occasionally abundant, and the feeding modes of heterotrophic protists exhibited a great variety (predominantly omnivores, bacterivores, herbivores or predators). Filter-feeding HF were of little importance. Contrary to the pelagic environment, a top-down control on total benthic bacterial numbers by HF seemed unlikely at the studied stations which were characterised by muddy sand.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Microbial ecology 27 (1994), S. 27-42 
    ISSN: 1432-184X
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Enclosure experiments in the mesotrophic Schöhsee in northern Germany were designed to study the impact of metazooplankton on components of the microbial food web (bacteria, flagellates, ciliates). Zooplankton was manipulated in 500-liter epilimnetic mesocosms so that either Daphnia or copepods were dominating, or metazooplankton was virtually absent. The bacterial community responded immediately to changes in zooplankton composition. Biomass, productivity, and especially the morphology of the bacteria changed drastically in the different treatments. Cascading predation effects on the bacterioplankton were transmitted mainly by phagotrophic protozoans which had changed in species composition and biomass. When Daphnia dominated, protozoans were largely suppressed and the original morphological structure of the bacteria (mainly small rods and cocci) remained throughout the experiment. Dominance of copepods or the absence of metazoan predators resulted in a mass appearance of bacterivorous protists (flagellates and ciliates). They promoted a fast decline of bacterial abundance and a shift to the predominance of morphologically inedible forms, mainly long filaments. After 3 days they formed 80–90% of the bacterial biomass. The results indicate that metazooplankton predation on phagotrophic protozoans is a key mechanism for the regulation of bacterioplankton density and community structure.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Journal of Pragmatics 15 (1991), S. 521-549 
    ISSN: 0378-2166
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Allgemeine und vergleichende Sprach- und Literaturwissenschaft. Indogermanistik. Außereuropäische Sprachen und Literaturen
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    ISSN: 0378-2166
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Allgemeine und vergleichende Sprach- und Literaturwissenschaft. Indogermanistik. Außereuropäische Sprachen und Literaturen
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    350 Main Street , Malden , MA 02148 , USA. , and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Science Inc
    Journal of cardiac surgery 18 (2003), S. 0 
    ISSN: 1540-8191
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract Background: Less invasive operation procedures without support of extracorporeal circulation are becoming increasingly important. A basic requirement for good long-term results in such cases is, however, the complete revascularization of the affected coronary vessels. The unsatisfactorily high conversion rate from bypass operations originally planned as off-pump to conventional operations with heart-lung machines, because of the failure to reach the target vessels on the rear wall of the heart through hemodynamic instability led to investigation of the efficiency of a microaxial pump (Impella elect) placed in the left ventricle. Methods: In a prospective project 15 of 38 consecutive patients selected for coronary revascularization with beating heart had a micro pump transaortically implanted in the left ventricle to support the heart during the operation with a flow rate of 2.5 to 3.9 l/min. Results: With 8 of 23 patients operated on without pump support, the operation had to be converted to conventional methods with a heart-lung machine. Only one patient out of the left-ventricle-supported group had to be further operated on conventionally because of a deep intramyocardial positioned left anterior descending coronary artery (LAD) (p 〈 0.05). The investigated laboratory parameters, especially creatine kinase (CK), CK-MB isoenzyme, and clotting showed no significant difference. There tended to be a higher blood loss recorded with the pump-supported patients. Conclusion: In summary, it appeared that the application of a left ventricular coaxial pump with comparable results seemed to make possible complete revascularization in nearly all patients.(J Card Surg 2003;18:240-244)
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Cambridge : Cambridge University Press
    Philosophy 19 (1944), S. 188-189 
    ISSN: 0031-8191
    Quelle: Cambridge Journals Digital Archives
    Thema: Philosophie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Molecular and Cellular Endocrinology 53 (1987), S. 33-44 
    ISSN: 0303-7207
    Schlagwort(e): Heteromeric receptor structure ; Receptor activation ; Receptor dissociation ; Sodium molybdate
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    FEBS Letters 179 (1985), S. 138-142 
    ISSN: 0014-5793
    Schlagwort(e): Glucocorticoid receptor ; Steroid-binding polypeptide ; Subunit structure
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Biologie , Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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