Regional distribution of thiamin pyrophosphokinase in rat brain

The highest specific activity of thiamin pyrophosphokinase was found in the cerebellum, and lower activity in cerebral cortex and midbrain. The regional difference in the enzyme activity was similar to that in thiamin content and the influx rate in rat brain, suggesting that the enzyme is involved in the thiamin transport.     

浅析加强英语听说能力的培养--从CET改革谈起

交际是学习语言的最终目的.大学英语四、六级考试改革突出了英语听说能力,其目的是促进学生重视英语交际能力.要提高学生英语交际能力,在英语教学中教师应正确处理好几对关系:听与说的关系;交际文化与语言文化的关系;教师与学生的关系;准确与流利的关系等,把握教学原则,从而加强学生的听说能力培养.     

论班级中差优生的管理

论述了学校班级中优、差生不同的管理方法,针对差等生的转化方法作出较为全面详细的说明.     

Induction of hemopoietic chimerism in the caprine fetus by intraperitoneal injection of fetal liver cells

Summary Intraperitoneal injection of allogeneic liver cells from 43-day-old male fetuses into normal 60-day female goat fetuses resulted in persistent hemopoietic chimerism in surviving recipients without clinical evidence of graft-versus-host disease. Transplantation of normal fetal liver cells into preimmunocompetent goat fetuses affected with -D-mannosidosis may provide an alternative strategy for evaluating hemopoietic stem cell transplantation in the treatment of human lysosomal storage diseases.     

Age distribution of circulatingα-interferon

Summary A sensitive radioimmunoassay showed that circulating -interferon in the plasma of healthy individuals was low in children and reached the highest level in the young adult, then declined gradually with age. Circulating -interferon was 0.201±0.059 ng/ml in males (n=19) and 0.184±0.076 ng/ml in females (n=14) at ages 30–39 years old. It was noted that circulating -interferon was maintained up to a certain level even in elderly individuals.     

Calcium release from frog sarcoplasmic reticulum by an imidazolyl reagent

Summary Calcium is released from the isolated heavy sarcoplasmic reticulum (SR) of frog skeletal muscle upon application of 0.1–1 mM diethylpyrocarbonate (DEP, an imidazolyl reagent). The Ca-ATPase activity of SR was suppressed by 20% in the presence of 1 mM DEP. More than 1 mM of free magnesium ion or 5 M ruthenium red eliminated the effect of DEP on calcium release but not on Ca-ATPase activity. A plausible site of DEP action is on the calcium channel.     

A new indolic antiauxin, α-(5,7-dichloroindole-3-)isobutyric acid: its chemical synthesis and biological activity

Summary A new potent antiauxin, -(5,7-dichloroindole-3-)isobutyric acid has been synthesized and shown to inhibit auxin-mediated elongation ofAvena coleoptiles and to stimulate root growth of rice seedlings. Its activity is stronger than -(p-chlorophenoxy)isobutyric acid and is comparable to that of 2,3,5-triiodobenzoic acid, which are typical antiauxins.     

The role of repair in radiobiology

Summary Apart from cancer and mutation induction, radiobiological effects on mammals are mostly attributable to cell death, defined as loss of proliferative capacity. Survival curves relate retention of that capacity to radiation dose, and often manifest a quasi-threshold (shoulder). The shoulder is attributable to an initial mechanism of repair (Q-repair) which is gradually depleted as dose increases. Another form of repair, which is not depleted (P-repair), increases the dose required to deliver an average of one lethal event per cell (dose D₀). Neither form of repair can unambiguously be linked with repair of defects in isolated DNA. An important initial lesion may well be disruption of the complex structural relationship between the DNA, nuclear membrane and associated proteins. One form of P-repair may be restoration of that structural relationship.     

关于E~(n+1)中全臍超曲面和极小超曲面的一个注记

本文利用改进了的一般极大值原理,给出了n+1维欧氏空间E~(n+1)中利齐曲率下方有界的完备连通超曲面为全脐超曲面或极小超曲面的一个充要条件。     

Lack of effect of dihydroergotamine on endothelial and smooth muscle cell proliferation and endothelial cell prostanoid production

Summary The most important effect of dihydroergotamine is venoconstriction, but certain metabolic effects and changes in vessel prostanoid activity have also been suggested. In this study endothelial cell production of 6-keto PGF₁ and TxB₂ was quantitated in vitro. No evidence of altered prostanoid production was noted after incubation with dihydroergotamine (exposure ranging from 5×10^–3 to 5×10^–7 g/l). Similarly, no effect of dihydroergotamine on the growth rates of endothelial cells or smooth muscle cells in vitro was documented.