Die anorganischen Bestandteile des Honigtaues vonMegoura viciae Buckt

Summary In the honeydew ofMegoura viciae Buckt., sucking on the sieve tube sap ofVicia faba, the following cations are present in measurable quantities: potassium (13.0–14.1 mg/ml), sodium (0.04–0.051 mg/ml), magnesium (1.8–2.3 mg/ml) and calcium (0.07–0.09 mg/ml). There are only traces of copper, iron, manganese, zinc, cobalt and molybdenum. Amongst the anions, phosphate was found at 1.9–2.5 and chloride at 0.02–0.05 mg/ml, whereas nitrate and sulphate could not be detected.     

Zur Frage der Natur der Ablagerungen in den Gichtknoten

Summary A gout-tophus, which we examined by X-rays and micro-crystallographic methods was definitely proved to be a deposit of monosodiumurate-monohydrate in the form of crystals which could just be detected under the microscope.     

Nachweis einer reflektorischen Natur der Jodazetat-Miosis

Summary Intravenous administration of iodoacetate (20 mg/kg) produces in cats a transient miosis. This is shown to be a reflex constriction elicited by an excitatory action of iodoacetate on the retina.     

Zur Frage der Natur der Ablagerungen in den Gichtknoten

Summary The spectrum of the aurora of April 17, 1947, exhibited again the forbidden line 5199 Å of the nitrogen atom and confirmed the long duration of this excitation calculated on the basis of theory at 5 hours.     

Histochemische Untersuchungen zur Natur der Cytoplasma-Einschlüsse des Lungentumors der Maus

Résumé Dans une étude histochimique on a montré que les inclusions cytoplasmiques des tumeurs pulmonaires de la souris (Klärner etGieseking) contenaient une polysaccharide neutre jointe à l'acide ribonucléique. Les résultats ont été discutés au sens d'une hypothèse virale.     

Die Algebra der Babylonier

Ohne Zusammenfassung Vorgelegt von B. L. van der Waerden     

Die Rouleau-Bildung der Rindererythrocyten

Summary Not a trace of rouleau formation could be observed with native beef erythrocytes under varying conditions. A typical rouleau formation and a markedly increased sedimentation rate could, however, be elicited when the surface layer of the beef erythrocytes was carefully removed with proteolytic enzymes. This is an additional evidence that the beef erythrocytes are enveloped in a surface sheet, which inhibits their hemagglutination and their rouleau formation. Papain is a proteolytic enzyme, which is inactive regarding rouleau formation. Lysolecithin disintegrates the rouleaus, albumin restores them.

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Diese Arbeit wurde von der H.-Buss-Stiftung (Basel) unterstützt.     

Die Konstitution der Salamander-Alkaloide

Summary Four alkaloids have been isolated from the skin gland of the Feuer- and Alpensalamander (Salamandra maculosa andatra Laur.). The structure, stereochemistry and absolute configuration of the principal alkaloid, samandarin, have been elucidated by chemical, optical, and X-ray-crystallographic methods. The basic structure of samandarin is derived from 5-androstan by the insertion between C-2 and C-3 of ring A of an NH group which, along with an oxygen bridge between C-1 and C-3, constitutes an oxazolidine ring; at C₁₆ there is a-hydroxyl group. By virtue of its origin and constitution samandarin occupies a unique position among alkaloids.

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Nach der am 15. Juni 1960 in der Aula der Universität Zürich gehaltenen zweitenPaul-Karrer-Vorlesung. Der Vortrag ist zum Teil gekürzt, Ergebnisse der letzten Zeit sind in die vorliegende Fassung eingearbeitet worden.     

Die Biochemie der Chinone

Ohne Zusammenfassung     

Die Welt der kleinen Planeten

Summary After a historical survey on the discovery of the small planets and the international organization of the calculation of orbits the importance of the divergences from the ordinary orbits between Mars and Jupiter is discussed. On the one side those small planets which approach Mars, Jupiter, even Earth and Saturn, in strongly excentric orbits offer new methods for the mass determination of the large planets; e.g. the perigee of Eros made possible a new determination of the parallax of the sun (8,79). On the other side the group of the Trojans e.g. gives new aspects for the problem of the three bodies. In the breaches of commensurability the statistical distribution of the orbits of the small planets hints to the problem of the stability of the planetary system.     

Die biologische Bedeutung der Vitamine

Summary The vital importance of the vitamins resides in theircoferment function, which enables them to catalyse enzymatic processes in living tissues. The term coferment is used in this connection to designate organic compounds of relatively low molecular weight, which in conjunction with the specific proteinous apoferments bring about the transformation of definite substrates. The vitamins are, however, catabolized like ordinary substrates when they come into contact with enzymatic systems in which they have no coferment function. This explains why normal life cannot be sustained, if the living organisms do not receive asnutritional factors the vitamins which they cannot synthesize. From a biochemical point of view not only exogenous hypo- or avitaminoses but all pathological changes may be regarded as the sequelae of disturbances in one or several enzymatic systems. The vitamins may exert a regulating influence also in these enzymatic disturbances which are not directly caused by vitamin deficiency. In such cases they will act asrèmedies.     

Die radiofrequente Strahlung der Sonnenkorona

Summary From the theory of the free-free-transitions of the electrons in the solar corona the absorption coefficient and optical thickness of the corona are calculated. From these the intensity of the coronal radiation at radio-frequencies is deduced for different distances from the centre of the sun's disc (Fig. 1). In fig. 2 the spectral intensity-distribution is given for radiation coming from the sun's centre (=0), from the sun's limb (=1), and from a point one solar radius outside the sun's limb.     

Die Beeinflussung der Mitose durch Urethan

Summary 2% aqueous solution of urethan causes after 6–10 hours' action on root types ofVicia faba andAllium cepa a shortening of chromosomes, it stops also the metaphase and lowers the rate of mitosis. Probably there is a connection between the lipophile groups, the reduction in surface tension, and the diminution of chromosomes. Dioxan with similar physical properties has the same effect.     

Die Alkaloide im Stoffwechsel der Pflanze

Ohne Zusammenfassung10. Paul-Karrer-Vorlesung, gehalten am 19. Juni 1968 in der Aula der Universität Zürich.     

Die physikalische Kieme der Wasserinsekten

Summary The air stores carried by a number of aquatic insects have: a) a hydrostatic function (Brocher, Oortwijn-Botjes, Thorpe, andCrisp); b) the function of an oxygen store (Ege, de Ruiter et al.) and c) the function of a physical gill (Strauss-Durckheim, Ege, etc.). The fact that oxygen is taken up from water with the aid of an air bubble was demonstrated forNotonecta by comparing the life time of insects with and without physical gill (while replenishing the oxygen store from the air was prevented) byEge, and forCorixa byPopham, whileVlasblom determined the oxygen uptake from water with and without air bubble forNotonecta, Naucoris, Corixa, Sigara andNepa. Nepa andSigara can take up considerable quantities of oxygen by cutaneous respiration.During the summer, the gill function of the air store ofNotonecta andNaucoris is of importance only when a water current passes along the animal, caused by ventilation movements of the legs (de Ruiter et al.). At low temperatures, however, the metabolic rate is so low that in many instances the physical gill provides the oxygen required without ventilation movements.An apparatus for the simultaneous determination of oxygen uptake from air and water (Wolvekamp andVlasblom) gave results that provided a means of evaluating the importance of the physical gill function.In some cases, the air store, although in direct contact with the water, does not need to be replenished. InAphelocheirus andElmis, the negative pressure in the bubble, caused by oxygen consumption and the diffusing out of part of the nitrogen, is compensated for by the mechanical resistance of a feltwork of thin hairs and the surface tension of the boundary layer of the water (Thorpe andCrisp). In the African beetle,Potamodytes, the unprotected air bubble is permanent because the strong river currents produce a lowered pressure around the animal according toBernoulli's principle (Stride).     

Die Treffermethode in der Messung der Parathyreozyten-Aktivität nach der Epiphysektomie

Résumé Par l'application de la méthode d'intégration aux points sur les clichés électronomicroscopiques, on a constaté l'hypertrophie des organelles cellulaires (mitochondries, le réticulum endoplasmique et l'appareil de Golgi) dans les cellules parathyroïdiennes de rats sacrifiés trois semaines après l'épiphysectomie.     

Die Beeinflussung der Leukozytenphagozytose mit Phlorrhizin

Summary In the rat the intraperitoneally administered phlorrhizin significantly reduces the phagocytosis of bacteria by leucocytes, as determined by thePlatonow-Ludány-Vajda method, with the mean decrease being — 33.5%. The effect is reversible. The phenomenon appears to be due to an alteration of carbohydrate metabolism in the leucocytes. The experiments supply new evidence supporting the view that alongside biophysical factors (surface effects) also cellular metabolic processes may play important roles in the phagocytotic activity of leucocytes.