尿嘧啶对单胺氧化酶的抑制作用

给青年小鼠(1月龄)po尿嘧啶25—800mg/kg对脑和肝MAO-B活性抑制作用与剂量成明显量-效关系,而对MAO-A抑制较弱。多次po尿嘧啶300mg/kg对老年小鼠(18月龄)脑MAO活性抑制作用明显强于对青年小鼠,并能增加老年小鼠脑组织5-HT和DA含量。另外,随年龄增加,小鼠血、脑和肝组织MAO活性显著升高,而上述组织中尿嘧啶含量则明显降低。体外实经证明,尿嘧啶对MAO-B活性抑制程度明显强子对MAO-A,并且对MAO-B为竞争性抑制,对MAO-A为混合型抑制。     

The Effect Of Technological Innovation On Hutterite Culture

Abstract

The Hutterites of North America are often envied by their rural neighbors as being efficient and productive agriculturalists who combine twentieth century technology with a life stylereminiscent of an earlier age. A closer examination of Hutterice culture reveals that a tension exists between these two elements.     

自血光量子疗法对放射治疗鼠肿瘤增敏作用的研究

本文应用多功能图像分析仪,检测了鼠Ｗ２５６移植性肿瘤细胞ＤＮＡ含量,探讨自血池子量子疗法（ＵＢＩ）对放射治疗的增敏作用,结果表明,经ＵＢＩ后放疗与单纯放疗的肿瘤相比,肿瘤细胞ＤＮＡ含量显著降低,而且肿瘤体积减小,细胞变性坏死显著,间质淋巴细胞数量明显增多,表明ＵＢＩ对肿瘤放射治疗有明显的增敏作用。     

The Effect Of Temperature and Of Relative Humidity On Sectioning Of Tissues Embedded In Polyethylene Glycol Wax

Experiments carried out in a sealed room, where temperature and humidity could be controlled at will, showed that a high relative humidity in the atmosphere interferes with microtome cutting of tissues embedded in polyethylene glycol wax. The higher the atmospheric temperature the less became the degree of relative humidity which could be tolerated if successful sections were to be obtained.     

Effect Of Glutathione On The Redox Transitions Of Naphthohydroquinone Derivatives Formed During Dt-Diaphorase Catalysis

The oxidation of GSH coupled to the redox transitions of 1, Cnaphthoquinone derivatives during DT-diaphorase catalysis was examined. The quinones studied included 1,4-naphthoquinone and its dimethoxy-and hydroxy derivatives and were selected according to their different ability to undergo nucleophilic addition with GSH and the dual effect of superoxide dismutase on hydroquinone autoxidation

GSH was oxidized to GSSG during the redox transitions of the above quinones, regardless of their substitution pattern. This effect was accompanied by an increase of total O₂ consumption, indicating the ability of GSH to support quinone redox cycling. The values for the relationship [O₂]_consumed[GSSG]_formde were, with every quinone examined, above unity. thus pointing to the occurrence of autoxidation reactions other than those involved during GSSG formation

These results are discussed in terms of the functional group chemistry of the quinones and the ther-modynamic properties of the reactions involved in the reduction of the semi- to the hydro-quinone by GSH     

Effect Of Sodium Hexanitrocobaltate (III) Decomposition On Its Staining Of Intracellular Potassium Ions

The effect was examined of the chemical decomposition of the potassium stain, sodium hexanitrocobaltate (III) (SHC), on its ability to produce stain granules of consistent size that could be used to estimate the K⁺ contents of stomafal guard cells. Stomata in detached epidermis from leaves of Vicia faba (fava bean) were stimulated to accumulate K⁺ by treating them with fusicoccin. Stomatal apertures and the fraction of guard cell area covered by K⁺ precipitate granules (K⁺ score) were measured by digitizing photographic enlargements, and K* scores were correlated with the age of stain that had been stored either in open or closed containers. The ability of stain aged in open containers to produce consistent fractional cell coverage was compared to 1) the ability of identically treated stain to precipitate K⁺ from solutions of KCl, and to 2) the kinetics of decomposition of SHC. It was found that the fractional coverage of guard cells of stomata opened to the same apertures decreased with a first order rate constant of 2.3 × 10^-8/sec. The mass of precipitate formed by treatment of KCl solutions was unchanged for 2 hr after initial preparation of the SHC, and decreased thereafter with a first order rate constant of 1.0 × 10^-5/sec. When stored in tightly sealed containers, nearly 100 hr were required for an occasionally opened bottle of SHC to decay to the same efficacy as a solution left open to the air for 8 hr.     

土壤中氨基酸的检测及组成

我们采集了江苏省及其他省（区）不同生物、气候条件下的土壤样品,采用同一测试方法研究了表土中的有机氮的变异特征及其影响因素。本文介绍实验土样的酸水介液通过乙酰丙酮──氯仿溶液并调节ｐＨ值的方法处理,以除去用色谱法测试土壤中氨基酸的最大干扰物－铁、铝。叙述了土壤中氨基酸检测技术及其组成。     

The Effect Of Commercial Bovine Serum Albumin And Other Proteins On The Activity Of Bovine Milk Galactosyltransferase

Abstract

The widespread use of bovine serum albumin preparations for the stabilization of purified glycosyltransferases has prompted us to study the effects of different preparations of albumins on the galactosyltransferase activity of bovine milk. For comparison, several other proteins were tested as well. The albumins caused a large stimulation of transferase activity (400–700%) which varied depending on the source of the albumin and the treatment to which it had been subjected. Several other unrelated proteins were tested for their effects on transferase activity. Some proteins stimulated, while others had little effect. Lysozyme stimulated the activity by 178% and poly-L-lysine had Vittle effect. Other proteins stimulated to variable extents. The stimulations obtained with albumin and myelin basic protein were noteworthy. The stimulation was considerably less marked when the enzyme was incorporated into lipid vesicles.     

同龄纯林密度效应新模型的研究

根据植物种群生物量增长模式和最终产量恒定理论,提出一种新的同龄纯林密度效应模型：V^-β=AN^β B。这里N和V分别为林分密度和平均单株材积;A、B、β分别是随生长阶段而变化的参数。采用杉木人工林密度试验材料进行验证,表明该模型能很好地拟合实际的观测资料,明显优于目前常用的密度效应倒数模型和二次效应模型,显示了较大的优越性和较高的准确性。在新的密度效应模型中,取β=1可得密度效应倒数模型,即密度效应倒数模型仅为本文新模型的一个特例。