爱资哈尔大学的中国留学生群体研究:以1931至1938年间为主

0引言近代以来,随着丝绸之路的开通,中、埃文化交流有了更多的形式,具体表现在有大量的中国学生以学术团体的方式前往埃及留学.埃及作为世界上最重要的文明古国之一,又是历史悠久的伊斯兰文化国家, 是许多中国留学生心仪的目的国, 而位于开罗的爱资哈尔大学更是最佳选择. 中国的回族青年自20世纪30年代起前往爱资哈尔大学留学....     

利用遥感和GIS对伊朗最大红树林群体的变化进行检测和模拟

正确理解红树林的变化趋势、数量并模拟其未来的发展趋势,对于有效地规划红树林保护措施至关重要.在这项研究中,研究对象是波斯湾最大的岛屿克什姆岛,是伊朗面积最大的红树林分布地区.通过使用遥感数据(Landsat和GIS),确定了2002年至2014年该地区的红树林变化情况.在研究的时间区间内,通过卫星图像数字化和基于最大似...     

印度河流域文明遗传层次的比较生物学分析

本文探索了约公元前2600年～公元1900年之间超过半个世纪印度古文明.由于气候、经济和社会的变化,使得其神秘消失,它被埋藏了将近4000年,直到英国和印度的考古学家在1920年偶然发现了它的废墟才被揭晓.印度河流域有超过1000个定居点,覆盖了至少100万平方公里,即目前的巴基斯坦和印度西北部.它是当时最大的城邦文明...     

Heat shock protein gene expression during Xenopus development

Stress-induced heat shock protein gene expression is developmentally regulated during early embryogen esis of the frog, Xenopus laevis. For example, a number of heat shock protein genes, such as hsp70, hsp90, and ubiquitin are not heat-inducible until after the midblastula stage of embryogenesis. Furthermore, the family of small heat shock protein genes, hsp30, are differentially expressed after the midblastula stage as well as being regulated at the level of mRNA stability. Many of these stress proteins are also synthesized constitutively during oogenesis and embryogenesis during which they may act as molecular chaperones as well as being involved in sequestering proteins in an inactive state until required by the developing embryo. Furthermore the induction of these stress protein genes has been correlated with enhanced thermoresistance. During stressful conditions heat shock proteins probably prevent aggregation or misfolding of damaged protei ns within the embryo.     

A centrosomal mechanism involving CDK5RAP2 and CENPJ controls brain size

Autosomal recessive primary microcephaly is a potential model in which to research genes involved in human brain growth. We show that two forms of the disorder result from homozygous mutations in the genes CDK5RAP2 and CENPJ. We found neuroepithelial expression of the genes during prenatal neurogenesis and protein localization to the spindle poles of mitotic cells, suggesting that a centrosomal mechanism controls neuron number in the developing mammalian brain.     

Degradation of phenylalanine in the presence of hydrogen peroxide

Summary UV-irradiation of phenylalanine by 253.7 nm light in the presence of hydrogen peroxide formed 5 ninhydrin reactive products and ammonia. Four of them were identified as aspartic acid, serine, alanine and lysine.Acknowledgments. This work was supported by the Council of Scientific and Industrial Research. Thanks are due to the Head of the Department for facilities and to. Mr.Rakesh C. Sharma for help.     

Mast cells enter a teleost's brain by Xth cranial nerve in response toDiplostomum phoxini (Trematoda)

Summary Experimental infection byDiplostomum phoxini of the brain of laboratory hatched and rearedPhoxinus phoxinus induces the migration along the Xth cranial nerve of periodic acid Schiff positive granular leucocytes (PAS-GLs). These differentiate and grow into cells that lie between the parasite and the neurones of the host. The transformed cells are associated with elevated levels of heparin and serotonin in the brain; little histamine was detected. The reactive cell is identified as a mast cell.This work was carried out with M.R.L. Johnston's guidance. Teresa Townshend is thanked for assistance with techniques to hatch and raiseP. phoxinus.     

两步法合成尼群地平的工艺改进

3 -硝基苯甲醛在酸催化剂作用下 ,与乙酰乙酸乙酯用生成纯 3-硝基苄叉基乙酰乙酸乙酯。该物质再与 β -氨基巴豆酸甲酯作用 ,在苄胺类复合催化剂作用下生成高纯度的尼群地平。杂质总含量小于 0 .5 % ;其中二甲酯对称物含量小于 0 .2 %。二乙酯对称物含量小于 0 .1%。