Die Verstärkung der pressorischen Vasopressin-Reaktion durch 2-Mercaptoäthylguanidin bei der Ratte

Summary 2-mercaptoethylguanidin enhances the blood pressure responses to small doses of vasopressine in the rat. This potentiation is statistically significant. The increase of the vasopressine reaction after 2-mercaptoethylguanidin is not due to an indirect effect of vasopressine on the cardiovascular system.

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Herrn Professor Z. M.Bacq danken wir für seine wertvollen Hinweise.     

Age-dependent changes of acid mucopolysaccharide excretion patterns in human urine

Zusammenfassung Die sauren Mucopolysaccharide im Harn von 37 Normalpersonen verschiedenen Alters (Säuglinge bis Erwachsene) wurden säulenchromatographisch fraktioniert und einzeln bestimmt.

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This study was supported by a grant from the Deutsche Forschungsgemeinschaft, Bad Godesberg.     

Über das Glucosid von 1,2-Diphenyl-3,5-dioxo-4-n-butyl-pyrazolidin (Phenylbutazon)

Summary The synthesis and properties of the acetylated glucoside of phenylbutazon are described. The deacetylation of this enol-glucoside, even under neutral conditions, failed because of the lability of this compound.     

Die Zucht vonLytta vesicatoria im Laboratorium und Nachweis der Cantharidinsynthese in Larven

Summary Adult males ofLytta vesicatoria (Coleopt., Meloidae) synthesize cantharidin, but females do not, although the substance is present in the females too. We developed a method for rearing larvae of this parasitic beetle in the laboratory. It is shown that there exist 7 larval stages and 4 hypermetamorphic forms (triungulinus, second larva,pseudochrysalis and fourth larva). Larvae from the second to the fifth stage (second larva) synthesize cantharidin. Therefore, we conclude that the substance present in the adult female is at least in part synthesized in the larval period. Nothing is known about the biological significance of this biochemical sexual dimorphism.

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Coleoptera, Meloidae.     

Disparolone,a novel tumor inhibitor derived from the gypsy mothPortheria dispar (L.)

Zusammenfassung Disparolon, als neue tumorhemmende Verbindung von Weibchen des Schwammspinners,Porthetria dispar L., wurde isoliert und als 7-Oxohexadec-cis-10-enol-(1) identifiziert und synthetisch dargestellt. Die Verbindung ist gegen Walker Karzinosarkom 256 in Ratten aktiv.     

Parthenogenetic reptiles: New subjects for laboratory research

Summary Problems preventing establishment of laboratory colonies of parthenogenetic lizards have been solved. Now, productive colonies of these lizards, which have remarkably little genetic variation, can be readily established and used not only for research on parthenogenesis but also for many kinds of experiments for which reptile systems are desirable. Research colonies can provide valuable specimens while reducing the exploitation of natural populations.We thank José P. O. Rosado and George W. Foley for technical assistance and Richard G. Zweifel for specimens, ideas and support.     

Attosecond control of electronic processes by intense light fields

The amplitude and frequency of laser light can be routinely measured and controlled on a femtosecond (10(-15) s) timescale. However, in pulses comprising just a few wave cycles, the amplitude envelope and carrier frequency are not sufficient to characterize and control laser radiation, because evolution of the light field is also influenced by a shift of the carrier wave with respect to the pulse peak. This so-called carrier-envelope phase has been predicted and observed to affect strong-field phenomena, but random shot-to-shot shifts have prevented the reproducible guiding of atomic processes using the electric field of light. Here we report the generation of intense, few-cycle laser pulses with a stable carrier envelope phase that permit the triggering and steering of microscopic motion with an ultimate precision limited only by quantum mechanical uncertainty. Using these reproducible light waveforms, we create light-induced atomic currents in ionized matter; the motion of the electronic wave packets can be controlled on timescales shorter than 250 attoseconds (250 x 10(-18) s). This enables us to control the attosecond temporal structure of coherent soft X-ray emission produced by the atomic currents--these X-ray photons provide a sensitive and intuitive tool for determining the carrier-envelope phase.     

磁处理对粘土在水和药剂水溶液中膨胀的影响

本文用Ensulin法和Tl法研究了磁处理对粘土膨胀的影响,证实了磁处理对粘土膨胀的抑制作用,其中包括磁处理对粘土在水中和阴离子、非离子活性剂水溶液中膨胀的抑制作用和对无机盐、阳离子活性剂、无机和有机阳离子聚合物等防膨剂的增效作用。研究表明,不同的磁感应强度对粘土防膨效果有不同的影响,不同体系有不同的最佳磁感应强度,但一般在60～200mT的范围。