Splenic enzyme systems as affected by hypothyroidism during pregnancy

Summary Influence of thyroid hormones on splenic activities and the role of the spleen during pregnancy were not known. The present study revealed that increased enzyme activities of spleen are associated with pregnancy, and hypothyroidism during gestation led to decreased activities, indicating that the thyroid gland influences them.The authors gladly acknowledge the encouragement given by Dr M. M. Razanasir and all other scientists of the division of physiology and climatology, IVRI, Izatnagar to complete this work.     

Effect of fluoride on in vivo nitrate reduction in rice leaves (Oryza sativa L.)

Summary Fluoride had no effect on in vitro nitrate reductase activity in rice leaves, but in vivo activity was strongly inhibited. It is suggested that fluoride brings about this inhibition by adversely affecting the physiological NADH generating system required for in vivo nitrate reduction.Acknowledgments. We thank Dr M.S. Naik for useful suggestions and discussion. C.S.R. is grateful to Indian Council of Agricultural Research for a Senior Research Fellowship.     

DNA synthesis in exocrine and endocrine pancreas after partial hepatectomy in Syrian golden hamsters

3H-thymidine autoradiography showed an enhanced DNA synthesis in acinar and islet cells of pancreas after partial hepatectomy in syrian golden hamsters. A significant nuclear labeling index of acinar cells was observed between 48 and 84 h and reached control levels by 120 h. An increased labeling index of islet cells was also observed, however, this increase was not statistically significant. These results indicate growth factor(s) produced after partial hepatectomy is capable of inducing DNA synthesis in pancreas.     

Toxic effects of methylmercury on spermatozoa in vitro

Summary In an in vitro investigation, methylmercury (MeHg) reduced the motility of rat spermatozoa probably by the inhibition of succinate dehydrogenase and ATPase activities. Concomitant morphological changes observed in the spermatozoa were coiled tails and kinks in midpiece and tail regions.     

Weitzenbock不等式的推广

本文将关于平面上三角形的经典的Ｗｅｉｔｚｅｎｂｏｃｋ不等式推广到球面三角形，平面上的ｎ边形和ｎ维欧氏空间中的ｎ－１维棱锥的三种情形。主要结论为（定理１）：假设（Ｓｎ－１）是ｎ维欧氏空间中的（ｎ－１）维棱锥，Ｓｎ－１是（Ｓｎ－１）的面积；ａ１，……，ａｍ，ｍ＝Ｃ２ｎ分别是它的棱长，我们有等式成立当且仅当（Ｓｎ－１）是一个正棱锥。     

Information revelation in sequential auctions with uncertainties about future objects

In many auctions, buyers know beforehand little about objects to be sold in the future. Whether and how to reveal information about future objects is an important decision problem for sellers. In this paper, two objects are sold sequentially and each buyer’s valuation for the second object is k times that for the first one, and the true value of k is sellers’ private information. The authors identify three factors which affect sellers’ revelation strategies: The market’s competition intensity which is characterized by the number of buyers, buyers’ prior information about the second object, and the difference degree between two objects which is characterized by k. The authors give not only conditions under which revealing information about the second object in advance benefits the seller, but also the optimal releasing amount of information in the market with two sellers and one seller, respectively.     

PLT15薄膜热释电红外传感器的研制

用射频磁控溅射法在Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ（１００）结构衬底上沉积了高度Ｃ轴取向Ｌａ改性的ＰｂＴｉＯ３（ＰＬＴ１５）薄膜．研究了ＰＬＴ１５薄膜的电晕极化方法,用此方法同时对多个热释电敏感单元进行了极化．利用ＰＬＴ１５薄膜制备了热释电红外传感器,薄膜厚度是２μｍ,真空蒸发的Ｎｉ－Ｃｒ电极面积为１．２ｍｍ×１．０ｍｍ,敏感元下的Ｓｉ（１００）基片用热ＫＯＨ和ＥＰＷ进行刻蚀．用所设计的热释电系数测试系统对ＰＬＴ１５薄膜样品进行了测试,研究了其热释电特性．测试结果表明,ＰＬＴ１５薄膜样品的热释电电流ｉｐ平均为２．１×１０－１１Ａ,而对应的热释电系数ｐ为２．５２×１０－８Ｃ·（ｃｍ２·Ｋ）－１．这类薄膜很适合制备红外传感器     

热加工降低板蓝根对狗肾上皮细胞的毒性

调查不同热加工阶段板蓝根样品对狗肾上皮细胞的毒性.选用常用于流感病毒检测和抗流感药物的狗肾上皮细胞作实验模型,采用MTT比色法研究菘蓝新鲜根、板蓝根、板蓝根煎剂三种样品对MDCK细胞的细胞毒性情况.结果显示:菘蓝新鲜根、板蓝根和板蓝根煎剂三种样品的细胞半数致死浓度分别为3.74、39.55和61.95 mg·mL-1.该结果表明,热加工可降低板蓝根对狗肾上皮细胞的细胞毒性,这可能与热加工过程中发生的美拉德反应相关.