气液色谱法测定有机溶质在碳酸丙烯酯-NaI溶液中的活度系数

<正> 本文报导了298.15、303.15、308.15、313.15K时,正已烷、苯、四氯化碳、氯仿、二氯甲烷在碳酸丙烯酯(PC)-NaI溶液中的无限稀释活度系数γ_1~∞和盐效应常数的气液色谱(GLC)法测定结果。并考察了温度的影响。     

Induction of the synthesis of thymidine kinase by aldosterone in the kidney of the immature male rat

Summary Thymidine kinase activity was studied in kidneys from immature male rats after administration of aldosterone. Kinetic studies showed that the enzyme activity reached its maximum level 24 h after aldosterone injection. That increase was specific for aldosterone and could be related to the synthesis of new molecules of enzyme.     

Strain differences in the pattern and intensity of wheel running activity in laboratory rats

Summary Wheel running activity rhythms of three inbred rat strains, ACI/Ztm, BH/Ztm, and LEW/Ztm, were compared in order to evaluate the effect of genetic differences on circadian rhythm parameters. Significant strain differences were found in the general pattern of the activity rhythms and their characteristic periodicities as well as in the amount and duration of wheel running activity and the timing of activity onsets and offsets. The results suggest that genetic differences exist in the coupling of the multiple circadian oscillators that generate the overall pattern of wheel running activity.     

Malignant hyperthermia: Molecular defects in membrane permeability

Summary Malignant hyperthermia (MH), a genetically inherited disorder of skeletal muscle, is due to molecular defect in membrane permeability. The alteration in membrane permeability is suggested to be due to enhanced phospholipase A₂ activity which is responsible for the increased level in sarcoplasmic Ca²⁺. The excess Ca²⁺ is responsible for muscle hyper-rigidity and enhanced rate of glycolysis, resulting in a rapid rate of lactic acid production and a low pH in MH muscle.     

Effect of intercalating mutagens on crossing-over inDrosophila melanogaster females

Summary In order to evaluate the effect of several intercalating compounds on crossing-over inDrosophila melanogaster females, acridine orange, acriflavine, chloroquine, ethidium bromide and quinacrine were fed separately to larvae ofy ct f/+++ genotype. Our results show that acridine orange, acriflavine and ethidium bromide increase significantly the recombination frequency at thect-f region and support the view that, for intercalating agents, there is a relationship between clastogenic activity and female recombination induction.     

对企业开展合理化建议活动的总结思考

坚持开展开门纳谏活动，可以促进企业的快速发展。介绍了企业开展合理化建议活动的形式与措施。并以实例分析总结了活动所取得的效应。     

几种抗肿瘤药物对ODC的抑制作用

本文报道用酸滴定法定量测定鼠伤寒沙门氏菌鸟氨酸脱羧酶活性的方法。测定了丝裂霉素、“776”香菇多糖、博来霉素、米托葸醌、顺氨氯铂、安瘤乳口服液、环磷酰胺等抗肿瘤药物对鸟氨酸脱羧酶活性的抑制作用。此外,还测定了丝裂霉素,“776”香菇多糖、博来霉素三种抗肿瘤药物对鸟氨酸脱羧酶活性抑制作用的动力学类型。     

Isometachromin,a new cytotoxic sesquiterpenoid from a deep water sponge of the family Spongiidae

Isometachromin (1), a new sesquiterpene-quinone that is related structurally to metachromin C (2), and the known compounds ilimaquinone (3) and and 5-epi-ilimaquinone (4), were isolated from a deep water sponge in the family Spongiidae; the structure of isometachromin was elucidated by spectral methods. Isometachromin exhibits in vitro cytotoxicity against the human lung cancer cell line A 549 (IC₅₀=2.6 g/ml), but not against P 388 murine leukemia (IC₅₀10 g/ml) and also exhibits antimicrobial activity.This research is Harbor Branch Oceanographic Institution (HBOI) contribution number 911. We thank Drs S. A. Pomponi and M. Kelly-Borges (HBOI) for sponge taxonomy, and Dr P. McCarthy and T. Peterson (HBOI) for antimicrobial data.     

1,4—二取代氨基脲的合成及抗菌活性

通过芳基脲与苯肼、苯甲酰肼的亲核取代反应和芳肼与尿素的亲核取代反应，合成了１５种新的１，４—二取代氨基脲化合物，其结构已经元素分析、ＩＲ、ＨＮＭＲ、ＭＳ等确证．初步生物活性试验表明对短小杆菌、沙门氏杆菌、绿脓杆菌、变形杆菌、金黄色葡萄球菌及根霉有不同程度的抗菌作用