Differential scanning calorimetry of chromaffin granule membranes.

Differential scanning calorimetry thermograms of native chromaffin granule membranes exhibit several peaks in the 15-35 degrees C region. Extraction of cholesterol increases the size of the melting peaks. Addition of Ca2+ ions does not seem to influence the lipid transitions.     

RNA synthesis in the sex chromosomes of the opossum,Didelphis virginiana. I. Female

Résumé Pour une étude quantitative de la synthèse du RNA, nous avons utilisé des chromosomes sexuels d'Opossum, morphologiquement faciles à distinguer en prophase et possédant des caractères cytogénétiques inusuels. Les résultats suggèrent que les deux chromosomesX des lymphocytes femelles sont actifs génétiquement (quoique l'un d'eux le soit moins que l'autre) pendant une courte période du cycle de la cellule.     

Cytostatischer Wirkungsmechanismus der Methylhydrazine

Summary Cytostatic active methylhydrazine derivatives split off formaldehyde after mild dehydrogenation with potassium hexacyanoferrate (III). It is suggested that the primary formedazomethines andN-hydroxymethylderivatives participate in cytostatic efficacy by their alkylating ability (aminomethylation). Formaldehyde alone and its condensation products with hydrogen peroxide especially bis-hydroxymethylperoxide may exert cytostatic effects too.     

Der Mathematiker Abraham de Moivre (1667–1754)

Summary Before examining de Moivre's contributions to the science of mathematics, this article reviews the source materials, consisting of the printed works and the correspondence of de Moivre, and constructs his biography from them.The analytical part examines de Moivre's contributions and achievements in the study of equations, series, and the calculus of probability. De Moivre contributed to the continuing development from Viète to Abel and Galois of the theory of solving equations by means of constructing particular equations, the roots of which can be written in the form . He also discovered the reciprocal equations. In the course of this work de Moivre discovered an expression equivalent to (cos +i sin ) ⁿ =cos n +i sin n and, following Cotes, he succeeded in expressing the nth roots of unity in trigonometric form.In the theory of series, de Moivre developed a polynomial theorem encom-passing Newton's binomial theorem and, in particular, a theorem of recurrent series useful in the calculus of probability.The demands of the calculus of probability led de Moivre to an approximation for the binomial coefficients for large values of n. The interaction between de Moivre and James Stirling, particularly in regard to the asymptotic series for log (n!), is treated at length. This work supplied the foundation for de Moivre's limit theorem for the binomial distribution.The calculus of probability, which occupied him from 1708 onward, became in time ever more the center of de Moivre's inquiries. Proceeding from contemporary collections of gambling exercises, de Moivre, by introducing an explicit measure of probability for the so-called Laplace experiments, found the beginnings of a theory of probability. De Moivre expanded the classic application of probability calculus to games of chance by addressing himself to the problem of annuities and by adopting Halley's work with its conception of Probability of life. De Moivre was the first to publish a mathematically formulated law for the decrements of life derived from mortality tables.

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Abkürzungen a.a.O. am angegebenen Ort = Verweis auf das nach Verfassern alphabetisch geordnete Literaturverzeichnis. Eine vor a.a.O. in runden Klammern angegebene Zahl kennzeichnet die entsprechende Nummer der im Literaturverzeichnis aufgeführten Arbeiten eines Autors. - AC Ars conjectandi = Jakob Bernoulli (4) a.a.O. - AE Acta Eruditorum - a.S. alter Stil⁴⁷ - BM Bibliotheca Mathematica - DMV Deutsche Mathematiker-Vereinigung - JL Journal Literaire - MA Miscellanea Analytica, London 1730 - n.S. neuer Stil⁴⁷ - PT Philosophical Transactions of the Royal Society of London - r.F. rekurrente Folge - r.R. rekurrente Reihe - SMA Miscellaneis Analyticis Supplementum, London 1730 - v. veröffentlicht (nur im Briefverzeichnis verwendet) Prof. Dr. Kurt Vogel zum 80. Geburtstag Vorgelegt von J. E. Hofmann     

Purin- und Pyrimidinbasen der Desoxyribonukleinsäure des Ehrlichschen Mäuse-Ascites-Karzinomas

Summary The proportion of purines and pyrimidines in the DNA of the Ehrlich mouse ascites carcinoma is examined and compared with the base proportion of the DNA from liver and kidney of the normal mouse. The following findings were obtained: The DNA of the ascites tumor contains more guanine and less cytosine and thymine than the DNA of the normal mouse. For guanine this difference is statistically significant. The changed base compound is discussed with regard to the changed growing rate in tumors and the altered chromosome structure in the Ehrlich ascites carcinoma.

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Durchgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Experimental brain tumours in dogs

Zusammenfassung Durch wiederholte i.v. Injektionen von gelöstem Methylnitrosoharnstoff werden bei 4 Hunden intrazerebrale Geschwülste induziert. Damit ist der Beweis erbracht, dass dieser Stoff nicht nur bei Nagetieren, sondern auch bei grösseren Säugetieren Geschwülste des Zentralnervensystems verursachen kann.     

Effect of calcium and temperature on histamine release from pig lung by compound 48/80

Zusammenfassung Es zeigt sich, dass die anaphylaktische Histaminausschüttung Calcium benötigt und bei neidriger Temperatur vollkommen gehemmt wird. Bei Zugabe der Substanz 48/80 erweist sich die dadurch hervorgerufene Histaminausschüttung als dosisabhängig und benötigt kein extrazelluläres Calcium. Die Reaktion wird bei niedriger Temperatur (4°C) nur teilweise gehemmt. Sie kann daher nicht als zweckmässiges Modell für das Studium der anaphylaktischen Histaminausschüttung der Lunge angesehen werden.

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This investigation was supported by United States Public Health Service Grants Nos. OH-00304 and HE-14179.