β－C_2S固溶体稳定的热力学研究

从热力学理论出发，利用Ｘ射线衍射定性和定量的方法，对β－Ｃ＿２Ｓ固溶体的稳定性进行了分析和研究。经热力学理论推导得出β－Ｃ＿２Ｓ稳定的热力学条件，即掺入的微量元素的化学位μ＿ｉ须小于β－Ｃ＿２Ｓ的反应自由焓△Ｇ＿β，μ＿ｉ＜△Ｇ＿β．并定量地计算出一种微量元素稳定β－Ｃ＿２Ｓ的临界掺加量为；多种微量元素对β－Ｃ＿２Ｓ的稳定性判断条件为：     

Intrauterine transfusions influence fetal leukocyte counts and subsets

Histamine is an important mediator in allergic reactions, gastric acid secretions, and neurotransmission in the central nervous system. Basophils and mast cells are the main sources of histamine, which is formed from L-histidine by histidine decarboxylase (HDC). However, the regulatory mechanism of HDC in these cells remains unclear. We examined the regulation of HDC activity and gene expression using a unique human mast cell line, HMC-1, after stimulation with phorbol 12-myristate 13-acetate (PMA) or ionomycin. HDC activity was increased from 52.1+/-0.4 (mean+/-standard deviation) to 154+/-6.9, or 105.6+/-6.2 pmol/min/mg protein (n = 3), 4 hours after stimulation with PMA (10 ng/mL) or ionomycin (10[-6] M). Although actinomycin D had no effect on this increase, cycloheximide completely inhibited the increase caused by these stimuli. The population of HMC-1 cells containing HDC protein was increased after stimulation with either PMA or ionomycin as evaluated by immunocytochemical analysis with anti-HDC antibody as a marker. HMC-1 constitutively expressed HDC mRNA, and its level was not increased with these stimuli. These results suggest that the increase of HDC activity in HMC-1 induced by PMA or ionomycin is regulated at the translational level.     

Experimental studies of mechanically-induced articular cartilage defects following implantation of allogeneic embryonal chondrocytes in a collagen-fibrin gel in chickens

Full thickness defects (diameter 1,7 mm; depth 2,5 mm) were created mechanically in articular cartilage and subchondral bone of the condyles of tibiotarsal joints of 9-month old chickens. This full-thickness defects were repaired with cultured allogenic embryonic chick epiphyseal chondrocytes from the tibiae and femura of 10-days-old chicken embryos. The cells were embedded in a collagen-fibrinogen-matrix. Controls were similarly operated, but received either no treatment or implants the delivery substance only. Healing of the defects was observed macroscopically, histologically, histochemically and histomorphometrically after 3, 12 and 24 weeks. This graft was successfully transplanted in mechanically induced defects in 80%. The resulting hyaline cartilage was structurally reorganized according to the host pattern and under the influence of environmental conditions. The articular zone preserved it's cartilaginous phenotype, whereas the subchondral regions were transformed into bone. 12 weeks after the operation the defects in the experimental group were completely filled. In all instances in this group, there was an initial extreme increase of mitotic rate and cell number. After 24 weeks normal and subnormal values were founded. The defects in the control groups healed with fibrocartilage. Our results showed, that only the defects in the experimental group were completely filled with reparative hyaline cartilage tissue. In the present study the mixture of cultured allogenic embryonic chondrocytes and a collagen-fibrinogen-matrix was used successfully as a transplant for repairing defects in articular cartilage of chickens. Thus allogenic transplantation of cultured embryonal chondrocytes appears to be one of the most promising methods for the restoration of articular cartilage.     

HIV arthritis

Whether reexposure of varicella-immune persons to varicella-zoster virus would protect against or predispose to development of zoster was analyzed. The rate of zoster in 511 leukemic recipients of varicella vaccine who had 1 or > 1 dose of varicella vaccine and in those who did or did not have a household exposure to varicella was determined. A Kaplan-Meier life-table analysis revealed that the incidence of zoster was lower in those given > 1 dose of vaccine (P < .05). A Cox proportional hazards analysis showed that both household exposure to varicella and receipt of > 1 dose of vaccine were highly protective (P < .01) against zoster. Thus, the risk of zoster is decreased by reexposure to varicella-zoster virus, either by vaccination or by close exposure to varicella.     

吏用Authorware开发CAI多媒体课件的几个关键技术

本文以CAI课件的开发制作过程遇到的一些关键的技术问题加以探讨．并结合实际制作介绍了一些技艺方法、     

波尔多液与石硫合剂的配制

波尔多液的配制。波尔多液是应用范围很广的杀菌剂,它是由硫酸铜、石灰和水混配而成的药液.配制原料：硫酸铜为蓝色的块状结晶,石灰以块状的生石灰为好.如果没有生石灰,使用粉状的消石灰也可,但用量要加大到30%.     

精彩展品

环保铁皮船 这艘铁皮船的动力由一支短短的普通蜡烛提供，不但前进、转弯等自如，而且支持时间可长达数小时，令不少买家非常感兴趣。专做德国生意的熊猫贸易老板陈祥龙认为，它既造价低廉又符合环保概念，在国外应该很有市场。凭他经验估计，以8元批发价拿到的产品，售价大约可以卖到12元，利润可观。     

日本年轻建筑师的现状——1960年代的这一群

一人脉对照 1 日本现代建筑师溯流 引领日本现代建筑进人成熟时期的领袖人物非丹下健三莫属。由师从丹下的模文彦（1928年-）、黑川纪章（1934年-）以及大高正人（1923年-）、菊竹清训（1928年-）等4人在1960年代创导的新陈代谢运动，使主流的欧美建筑界开始认真关注一个亚洲的小国——日本的建筑活动。可以说新陈代谢运动是日本现代建筑发展的基石也是随后其建筑发展的原动力。