Neuformulierung der Kristallographie

Summary A consideration of symmetry in any object or process entails essentially a correlation between parts of a unit or between unit and unit. Enquiry must be made as to what is geometrically distinguishable or indistinguishable and an attempt undertaken to discover the pattern underlying apparent disorder.Crystallography has been the science in which the principles of symmetry have been most extensively applied and received their fullest development. Naturally enough, the system evolved for formulating the symmetry inherent in crystals has been adapted to the specific problems the crystallographer sets out to solve.Such researches, however, go far beyond the bounds of ordinary geometric crystallography and are, in particular, an essential requisite for mastering the problems of stereochemistry. It is, therefore, obviously desirable to find a method of formulation which can be applied to any or all the problems in which the question of symmetry arises, such as the systematic ambiguities or the possible deformations of objects or processes endowed with symmetry. To this end the Element of Symmetry, traditional starting point of investigations into symmetry, must be replaced by the covering operations as such.Symmetry formulæ can be deduced, which beyond merely describing the features involved, permit the detailed numerical calculation of their development and variation. In this respect they must prove of value not only to the chemist in his investigation of isomers etc., but can usefully be adopted also by the crystallographer.A short introduction into this new method of formulation is given in the preceding pages.     

Proliferationen der Fischepidermis nach der Einwirkung von inhibitoren des glykolytischen Energiestoffwechsels

Summary When fluoride-ions or monoiodoacetate is added to the ambient medium, there occur in fish larvae after 12 h, and in eels after 24 h, in some places, solid epidermal proliferations. The effect of glycolysis inhibitors on epidermal mitotic activity might be due to an impairment of energy metabolism as it is nullified by a simultaneous application of inorganic diphosphate or by doubled O₂ partial pressure of 320 mm Hg.     

Verlust der Proliferationsfähigkeit der Hepatozyten nach subtotaler Hepatektomie

Summary After resection of 90% of liver tissue, no significant increase of thymidine-³H labelling or mitotic index of hepatocytes can be observed in rats. The minimum residual liver mass critical for inducibility of proliferation and, in consequence, essential for survival of rats is more than 10% and less than 18% of the total liver parenchyma.     

Zur Kenntnis der Formazylverbindungen

Summary 1-benzal-2-4-diphenyltetrazene is obtained in highest yields by reaction of benzalphenylhydrazone with benzene diaziniumchloride at pH 4–8. This reaction is reversed by treatment with hydrochloric acid. In pyridine or alcohol solution the tetrazene suffers an intramolecular transposition to triphenylformazane.     

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.     

Aus der Chemie der Naturstoffe

Summary This lecture was held in Zürich to commemorate the 70^th birthday of Prof.Paul Karrer; it briefly outlines his life-work as a scientist and then reviews, in greater detail, some of his important work in various fields: vegetable dyestuffs (carotenoids), vitamins (particularly vitamins A, E and K) and curare alkaloids.As is the purpose of this lecture, a review is also given of the author's own work: ergot alkaloids and their derivatives; cardiac glycosides of squill, digitalis etc.; and finally, the most recent results of research on chlorophyll — the crystallization of natural chlorophylla andb after many years of endeavour.

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ErstePaul-Karrer-Vorlesung, gehalten im Rahmen der öffentlichen Feier zum 70. Geburtstag von Prof.Paul Karrer, am 25. April 1959 in der Aula der Universität Zürich.     

Zum Problem der Nahrungspflanzenwahl der Aphiden

Summary OnAllium schoenoprasum L. andPoa pratensis L., two species that do not belong to the host plants ofMegoura viciae Buckt., this aphid pierces the sievetubes as in its natural host,Vicia faba L. In none of these plants do the aphids take up³²P from the parenchyma. Presumably phloem-sucking aphids probe, before finally settling in the sieve-tubes of the plant, to recognize the quality of the plant.     

Zur Thermodynamik der Trombenbildung

Summary Koschmieder's new thermodynamical theory of tornado formation (1940) makes it probable that a tornado (or a waterspout) develops when a warm air packet rises quickly within the convective mother cloud. In the present paper the three principle cases of conditions are indicated under which supplementary amounts of potential energy necessary to start a daughter convection in the cumulo-nimbus cloud can become available in the latter. Supply of moister air from below seems to be at least as important as that one of warmer air. However, the suddenness of the release of the said supplementary energy cannot be explained by the abrupt annihilation of an intercepting layer within the main body of the cumulo-nimbus, for the pre-existence of such a layer is incompatible with the general character of this type of cloud.     

Zur Methodik der Artefaktausschaltung bei Anwendung von Diazoniumsalzen in der Histochemie (Phosphatasen,Esterasen usw.)

Summary A post-incubation with 1% sulfanilic acid solution in 10% CH₃COOH (approx. 2–10 min) or 5–10% potash alum or 0.5 mol AlCl₃ in 0, 1n HCl-after the histochemical reaction with diazonium salt-prevents N₂ formation. This gas originates from decomposition of tissue adsorbed diazonium salt which occurs after mounting in glycerin jelly. The inhibition of diazo-group disintegration depends, in the case of sulfanilic acid, on the formation of a diazoamino compound or double salt production with aluminium ions in the case of AlCl₃.     

Zur Frage der Alternsforschung

Summary Starting from the social problem of increasing average age, the aims and methods of modern research on ageing are discussed. They are based on experiment and observation of the ageing processes over the whole span of life from birth to death, corresponding to the shifting of the steady state characterising the living. Here, the energy economy of the organism, the maintenance of the biopotentials and the biotone are of special importance. The energy requirement is measured by means of the basal metabolism, this depending on the size of the organism. In this connection, the hypothesis ofRubner concerning the constancy of the amount of energy convertible per individual is discussed. Further considerations are given to the course of the ageing processes, whether of single organs or of a population of organisms. The survival statistics of the latter may be interpreted according toPütter as the result of the combat between damage and resistance. The connection between the change of adaptive and regenerative capacity and the diseases of old age is mentioned. Finally, the psychological and mental aspects are emphasised. In addition to statistical studies on senescence, prolonged observation on single individuals is afforded and suitable tests to follow the ageing processes have to be elaborated.

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Einführendes Referat anlässlich des Symposiums der Schweizerischen Gesellschaft für Gerontologie vom 11. Dezember 1954 in Basel (Vorsitz Prof.Verzár). Referate der Vorträge siehe Schweiz. med. Wschr.85, 686 (1955).     

Zytologische Untersuchungen an der Reblaus-Blattgalle

Summary Up to 9 types of cell nuclei, distinguished by their size, were found in the tissue of galls, which are produced by the vine louse. The growth of the cell nuclei probably proceeds in a series of prophase-like intermediate stages from one type of nuclei size to the next largest by means of endomitotic or endomitosis-like processes.     

Partielle Sprengung der Erythrocyten

Summary Highly polymerized hyaluronic acid coagulates the hemoglobin of several erythrocytes. The erythrocytes with coagulated hemoglobin do not hemolyze at pH 2 to 3.6, but very soon explode and set free within 1 or 2 sec hundreds of hemoglobin granules. The remaining membranes retain some of the hemoglobin and reveal several splits after the termination of the explosion. Judging from the splits, three layers of erythrocyte-membrane could be surmised. 0,5% tannic acid elicits a similar but less clear-cut phenomenon without a typical explosion.

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

Benzyn-Zwischenprodukte in der nukleophilen aromatischen Substitution

Summary Many substitution reactions of aromatic halides, such as amination with metallic amides in ammonia or amine solutions, high-temperature alkaline hydrolyses and arylation with phenyllithium, lead to the formation of rearrangement products as the result of a common reaction path involving unstable benzyne intermediates. The chemical evidence in favor of this reaction mechanism is discussed as are correlations of observed product compositions and applications to practical synthetic procedures.

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Contribution No. 2390.     

Ein Sensibilisator der therapeutischen Digitaliswirkung

Summary Complexes of bivalent tin with polyoxybenzene-polysulfonic acids have a diuretic effect, when injected subcutaneously in dogs or rabbits. The same compounds also sensibilize the cardiotonic effect of digitalis-substances on the isolated heart or on fragments of the isolated heart as usually employed for testing digitalis-substances.In a small number of patients suffering from heart disease, a rapid increase of their till then lowered diuresis was induced through subcutaneous injections of a solution of the above mentioned tin complex.     

Desazetylierung von Cardenoliden mit der Zinkazetatmethode

Summary Some examples of transesterifications of cardenolidacetates to acetyl-free glycosides with zincacetate are reported. The method is advantageous for the deacetylation of acetates with base-resistant acetyl groups or with special base sensitivity.

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56. Mitteilung über Herzglykoside. 55. Mitt. s. Helv. chim. Acta51, 1317 (1968).     

Die lokale Leukozytenreaktion bei der intraperitonealen Infektion der Maus mitE. coli

Summary Intraperitoneal aggregation of leucocytes is produced in an identical manner by intraperitoneal application of different amounts of living and dead bacteria and bacterial products. The maximum accumulation occurs with medium dosages of bacteria or their products, with high dosages no leucocytic accumulation is produced. Pretreatment with selected LPS of bacteria enhances the intraperitoneal accumulation of leucocytes also with the high amounts of bacteria, whereas the reaction in not pretreated with LPS is suppressed. Parallel to the increase of the intraperitoneal leucocytic accumulation the animals are protected against the infection with high amounts of bacteria, to which they succumb if not pretreated with LPS.     

Elektrophysiologische Untersuchungen an der Seitenlinie vonXenopus laevis

Summary Electrophysiological recording of the spontaneous activity from a single group of lateral sense organs on the abdomen ofXenopus laevis results in a more or less regular series of large spikes, either all of the same height or of two different sizes (each group is innervated by two large lateralis fibres). Mechanical stimulation of such a group may cause a rise or a fall of spontaneous impulse frequency. There is evidence for a two-directional sensitivity of the same unit (nerve fibre) from a single group, out of the middle as well as out of the dorsal lateral line.     

Beitrag zur Frage der Eisenresorption

Summary In rabbits whose intestinal tract has been sterilised by means of penicilline and terramycine, there is no detectable iron resorption, even when the animals are made anaemic.Iron resorption can be restored by means of addition of terramycine-resistentE. coli or Enterococci to the diet.     

Nachweis der Selbst-Erregung der circadianen Periodizität bei Carabiden (Coleoptera Ins.)

Summary Most of the active individuals ofCarabus cancellatus (Coleoptera) investigated were synchronized by zeitgeber-lengths of 8/8 10/10 or 16/16 h. On the other hand, a smaller number of beetles lost the periodicities of these Zeitgebers and showed a circadian activity rhythm. According to these experiments, the existence of a self-sustained circadian oscillation in carabid beetles is demonstrated. As we believe, a special numerical method of computing the length of activity periodicities was used for the first time.     

Der elektrophysiologische Nachweis der propriozeptiven Muskelafferenz und des monosynaptischen Reflexbogens der inneren Kehlkopfmuskeln

Summary On excitation of the superior laryngeal nerve and the recurrent nerve with single square wave shocks in patients undergoing total exstirpation of the larynx for cancer, a reflex potential can be recorded from the vocal muscle. This potential shows the criteria characteristic of the reflex potential arising on excitation of muscle spindles or the afferents of muscle spindles (la-fibres) in limb muscles. The pathway of afferent fibres is for the main part via the sup. lar. nerve but there seems to be an indication of a small part of afferents in the recurrent nerve also.