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  • 1
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The problem whether the molecular size of horseradish peroxidase is significantly altered when the enzyme is injected into the blood stream in tracer studies, has been studied by molecular sieve chromatography (gel filtration). The results obtained rule out the possibility that the horseradish peroxidase molecule (containing about 20% carbohydrates) is significantly degraded by carbohydrate-splitting enzymes or by proteases in the circulation into a smaller active unit. Furthermore, significant binding of peroxidase to plasma proteins or polymerization of the enzyme, has not been detected. It is concluded, therefore, that conclusions about the size of functional pores based on the known molecular weight (40000 daltons) are permitted, when the enzyme is used in permeability studies.
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  • 2
    ISSN: 1432-2242
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Naturally occurring parthenogenesis in unfertilized turkey eggs was encountered at this station in 1952. Since its discovery, selective breeding on a family basis has been practiced yearly in an attempt to further intensify this trait in certain lines of turkeys and chickens. Cytological studies likewise have been conducted and various experimental procedures employed in an attempt to develop a clearer picture of just where and the manner by which diploidy is restored. Available Cytological data and indirect evidence secured in related studies indicate that restoration of diploidy in unfertilized turkey ova is due to suppression of the second polar body. It would appear that in the absence of sperm, meiosis II is not completed. Chromosomes of the second polar body and those of the egg pronucleus probably never completely separate and subsequently the unfertilized ovum resumes development with a diploid complement of chromosomes. Four potential uses of unfertilized turkey eggs and parthenogenetic poults in biological research are given.
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  • 3
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The calculations of the electronic structure and conformational analysis of the acetanilide were carried out using the CNDO/2 method. The results show that the endo form is 1.2 Kcal/mole more stable than the exo form. The most stable conformation of the exo isomer corresponds to the dihedral angle of 90 ° between the phenyl and acetamide plane, whereas the minimum energy conformation of the endo isomer corresponds to the dihedral angle 50 °–60 °. A comparison of the calculated and experimental dipole moments suggests also the dihedral angle of 50 °–60 °. A comparison with experiment indicates that this molecular orbital method is good for conformational analysis and gives electronic structure which is compatible with spectroscopic measurement. The calculated conformational analysis and electronic structure of the acetanilide are in excellent agreement with experiments.
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  • 4
    ISSN: 1434-4726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die verschiedenen Prinzipien, die bisher bei der Messung der Ciliar-Aktivität angewendet wurden, kann man ungefähr unterteilen in indirekte Methoden, bei denen die Geschwindigkeit des Schleimflusses bestimmt wird, und in direkte Methoden, bei denen die Anzahl der aktiven Cilien-Schläge pro Zeiteinheit gemessen wird. Die 3 verschiedenen Prinzipien der direkten Methode sind: 1. Stroboskopie, 2. Mikrokinematographie und 3. Mikrophotooscillographie. Letztere Methode, welche wir für die Bestimmung der Ciliar-Aktivität im menschlichen Respirationstrakt benutzten, besitzt den großen Vorteil, die Aktivität einer einzigen Cilie zu differenzieren und zu messen, während die anderen beiden Methoden häufig die Aktivität eines ganzen Büschels von Cilien messen. Man erhält das Resultat in Form einer Kurve, die direkt die Frequenz der Cilienschläge zeigt. Die Excisate von Cilien-Epithel wurden vom. hinteren Teil der Nasenhöhle, vom Larynx und aus der Carina gewonnen. Die mikrophotooscillographische Methode ist relativ leicht als klinische Routinepraxis anwendbar und gestattet die Beobachtung sowohl des Effektes verschiedener Drogen auf die Cilien-Funktion als auch die der Cilien-Aktivität in verschiedenen Stadien von Erkrankungen.
    Notes: Summary The various principles which have been applied in measuring the ciliary activity may be divided, roughly, into indirect methods in which the rate of the mucous flow is determined and the direct methods in which the number of active ciliary beats per time unit is measured. The three different principles of the direct method are: (1) Stroboscopic, (2) microcinematography, and (3) microphotooscillographic. The latter method, which we have used in studies on ciliary activity in the human respiratory tract, possesses the great advantage of being able to differentiate and measure the activity of the individual cilium, whereas the other two methods often measure the activity of a cluster of cilia. The result is obtainable in the form of a curve showing directly the frequency of the ciliary beats. The biopsies of ciliated epithelium were removed from the posterior part of the nasal cavity, from the larynx, and from the caring. The microphotooscillographic method is relatively easy to employ as a routine in clinical practice and is applicable for investigating the effect of various drugs upon ciliary function as well as the activity in various disease states.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 257 (1972), S. 288-291 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A sample of sodium was bombarded by proton, helium, and oxygen beams and the subsequentK X-ray spectra measured. The spectra exhibit a preponderance of structure which is speculated upon in light of HFS calculations. The strongest lines are ascertained to be the normalKα satellite spectra produced by multiple electron vacancies in single ion-atom collisions.
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  • 6
    ISSN: 1434-4726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Aktivität der Cilien der Atmungswege wurde an einer Gruppe normaler Personen und einer mit schweren Kehlkopferkrankungen mittels der Mikrophoto-Oseillographie untersucht. Bei dem Versuch, die Cilienaktivität starker Raucher gegenüber mäßigen und Nichtrauchern zu vergleichen, fanden wir wie vorangehende Autoren die Aktivitat bei gemäßigten und schweren Rauchern vermindert oder völlig aufgehoben. Die Möglichkeit eines carcinogenen Effektes des Zigarettenrauchers wird in bezug auf die verminderte Cilientdtigkeit diskutiert. Schwerlösbare Carcinogene, die auf die Bronchialschleimhaut gelangen, können so lange Zeit mit der Schleimhaut in Kontakt bleiben und ihre Wirkung ausüben.
    Notes: Summary Using the microphoto-oscillographic method for recording ciliary activity in the respiratory tract we studied ciliary function in a group of normal persons and in patients having various laryngeal diseases. We tried to assess ciliary activity in heavy smokers versus moderate smokers/non-smokers. Like previous authors we found ciliary activity to be reduced or totally abolished in moderate and in heavy smokers. The possibility of the carcinogenic effect of cigarette smoking is discussed in the light of the reduced ciliary activity. Heavily soluble carcinogens trapped in the bronchial mucosa will thus be able to remain in contact with this mucosa for a long time and exert their action.
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  • 7
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Bombardment of cobalt with 42 MeV oxygen ions is seen to produce multiple inner shell electron excitation.Kα andKβ X-rays are measured and compared to Hartree-Fock-Slater calculated energies. This study of cobalt is the highestZ element where the satellite X-ray spectrum has been studied with good resolution.
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  • 8
    ISSN: 1573-9686
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract A large number of calves maintained up to two weeks with the Kwan-Gett artificial heart have had elevated central venous pressure with associated ascites, edema, oliguria responding to diuretics, and increased body weight and weight of organs at autopsy. This has been described as right heart failure syndrome and has been a problem limiting survival with the artificial heart. The high venous pressure has been attributed to inadequate pumping characteristics of the heart as well as imperfect fit which obstructs venous return. A new design of an artificial heart was tested on the mock circulation and in one calf with encouraging results. Venous return remained unimpaired during the artificial heart test in the calf. The heart is designed with the following main characteristics. (1) Highly flexible ventricular diaphragm. (2) Low resistance to inflow. (3) Parallel disposition of artificial ventricles and artificial atria for a better anatomical relation to the natural ostia. (4) Artificial atria with air chambers vented to the atmosphere. The increased compliance of the atrial walls prevented reduction of venous return caused by vacuum applied to the ventricles during the filling period. Although the heart compromised lung space, it demonstrated the need for still another new design which will not obstruct venous return and will maintain normal venous pressures without compromising lung space.
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  • 9
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Analytical chemistry 44 (1972), S. 284-289 
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
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  • 10
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 35 (1970), S. 1912-1915 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
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