Glutaminase I activity in guinea pig and rabbit liver and kidney tissues

Zusammenfassung Aktive Glutaminase I wurde in Meerschweinchen- und Kaninchenleber, in Nierengewebsextrakten und in Mitochondrienpräparaten der erwähnten Organe bei pH 7,2 nachgewiesen.dl-Glutaminsäure bewirkte eine ausgesprochene Hemmung des Enzyms nach Zusatz von Phosphat. In hypertonischer Sukrosenährlösung lässt sich eine Aktivierung durch Phosphatzusatz gewöhnlich nicht nachweisen, selbst nicht beim pH-Optimum 7,2, es sei denn bei sehr hohen Phosphatkonzentrationen.     

Effect of daily parenteral injection of betamethasone on histamine concentration of gastric tissue in albino rats

Summary Gastric tissue histamine concentration was determined in albino rats following daily parenteral injection of betamethasone over a period of 12 days. The result shows a highly significant fall in gastric tissue histamine concentration in comparison with that in saline-treated albino rats over a similar period.This investigation was carried out as a part of a project supported by a research grant from Medical Research Centre, Bombay Hospital Trust, Bombay, India.     

Mite parasitism of moths: Examples of paleosymbiosis in Dominican amber

Summary Two adult moths (families Gracillariidae and Tineidae) in Dominican amber each contained a pair of larval parasitic mites attached to their bodies. The larval mites were identified as belonging to the family Erythraeidae and represent the first fossil evidence of moths parasitized by mites. Phylogenic and evolutionary implications of this find are discussed in light of similar extant associations.     

A technique for establishing parabiosis between houseflies (Musca domestica L.)

Zusammenfassung Es wird eine neue, sehr einfache Methode zur Erzeugung parabiotischer, 12–24 h lang lebensfähiger Fliegenpaare (Musca domestica L.) beschrieben.

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The author wishes to thank Prof.K. N. Saxena for encouragement.     

Ni2MnGa铁磁形状记忆材料

铁磁形状记忆合金 (FSMA)是在一定温度范围马氏体相稳定同时又具铁磁性的一类特殊的形状记忆合金。Ni2MnGa铁磁形状记忆合金近年来成为呈现磁场驱动大应变的新型驱动材料 ,这些应变来自磁场诱发马氏体孪晶的重排 ,而不是磁场对奥氏体至马氏体相变的作用。孪晶变体的重排在宏观上呈现为正或切应变 ,一非化学计量比Ni2 MnGa单晶于室温加 0 .4T磁场能产生6 %的应变 ,Ni Mn Ga单晶在高至 15 0Hz的交变磁场仍可得到 2 .5 %的应变。本文阐述了与这种磁控形状记忆效应相关的孪晶界迁动的磁学和晶体学理论。马氏体相的大磁晶各向异性能使磁化沿c轴方向有利 ,穿过孪晶界c轴刚好转动 90度 ,同时 ,这个孪晶界也构成了约 90度的畴界。在各向异性的情况下 ,孪晶界的迁动仅有相邻孪晶变体的Zeeman能差驱动 ,μ0 ΔMis·Hi。磁场和外应力对应变的影响通过对一简单的自由能表达式取极小值来表示 ,自由能表达式包括Zeeman能、磁晶各向异性能和外应力以及在某些情况下需考虑的内部弹性能 ,模型的所有参数可通过应力 应变曲线和磁化曲线测量得到。铁磁形状记忆合金的磁场诱发应变可类比传统热弹性形状记忆效应 ,与更为人们所熟知的磁致伸缩现象不同。     

Survival and endogenous spleen colonies of irradiated mice after skin wounding and hydroxyurea treatment

Summary Wound trauma-induced survival from radiation may be related to increased mitosis in hematopoietic cells. This is supported by the cell cycle-dependent drug hydroxyurea, which 1. blocked survival of wounded mice injected 2 or 3 days after 900 rad and 2. reduced the number of endogenous CFU-s in wounded mice injected shortly before 700 rad.Supported by the Armed Forces Radiobiology Research Institute, Defense Nuclear Agency, under Research Work Unit MJ00018. Views presented in this paper are those of the authors; no endorsement by the Defense Nuclear Agency has been given or should be inferred.Research was conducted according to the principles enunciated in the Guide for the Care and Use of Laboratory Animals prepared by the Institute of Laboratory Research, National Research Council.     

A modified RNA polymerase transcribes a cloned gene under sporulation control in Bacillus subtilis.

A modified form of RNA polymerase from Bacillus subtilis selectively transcribes a cloned gene under early sporulation control. This RNA polymerase lacks sigma factor but contains a newly identified subunit of molecular weight 37,000, termed P37. P37 could be a regulatory protein that controls, at least in part, an early stage of spore development.