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In order for China to play a bigger, more positive role in the world, it is important for China to have a healthy capital market. This perception motivates us to examine the health of China''s capital market, especially the severity of the overall loss of the listed companies in China and the effects of accounting irregularities on the losses. We show the overall loss of the listed companies was very severe, in particular, crisis-like behavior emerged in the fourth quarter of 2002, 2004, 2005, and 2008. We further observe that loss in the fourth quarter was much greater than the average loss of the first three quarters in the same year. The most straightforward interpretation of this loss pattern is that companies underreported losses in the first three quarters, to boost their stock values in most time of the year. However, in the fourth quarter, accounting balance of the whole year dictated that the reported loss in the fourth quarter had to be much greater than the actual loss. Fortunately, such irregularity has been greatly reduced, thanks to the accounting reforms in China in 2007. 相似文献
95.
Role of receptor internalization in the agonist-induced desensitization of cannabinoid type 1 receptors 总被引:2,自引:0,他引:2
Wu DF Yang LQ Goschke A Stumm R Brandenburg LO Liang YJ Höllt V Koch T 《Journal of neurochemistry》2008,104(4):1132-1143
Agonist-induced internalization of G protein-coupled receptors (GPCRs) is an important mechanism for regulating signaling transduction of functional receptors at the plasma membrane. We demonstrate here that both caveolae/lipid-rafts- and clathrin-coated-pits-mediated pathways were involved in agonist-induced endocytosis of the cannabinoid type 1 receptor (CB1R) in stably transfected human embryonic kidney (HEK) 293 cells and that the internalized receptors were predominantly sorted into recycling pathway for reactivation. The treatment of CB1 receptors with the low endocytotic agonist Δ9 -THC induced a faster receptor desensitization and slower resensitization than the high endocytotic agonist WIN 55,212-2. In addition, the blockade of receptor endocytosis or recycling pathway markedly enhanced agonist-induced CB1 receptor desensitization. Furthermore, co-expression of phospholipase D2, an enhancer of receptor endocytosis, reduced CB1 receptor desensitization, whereas co-expression of a phospholipase D2 negative mutant significantly increased the desensitization after WIN 55,212-2 treatment. These findings provide evidences for the importance of receptor endocytosis in counteracting CB1 receptor desensitization by facilitating receptor reactivation. Moreover, in primary cultured neurons, the low endocytotic agonist Δ9 -THC or anandamide exhibited a greater desensitization of endogenous CB1 receptors than the high endocytotic agonist WIN 55,212-2, CP 55940 or 2-arachidonoyl glycerol, indicating that cannabinoids with high endocytotic efficacy might cause reduced development of cannabinoid tolerance to some kind cannabinoid-mediated effects. 相似文献
96.
关于几种避孕植物药的药理初筛及成份预试 总被引:4,自引:0,他引:4
本文对云南滇西地区民间用于避孕和绝育秘方中的槌果藤,野花椒寄生、花椒寄生、螃蟹树寄生、鸡矢藤及野花椒的醇提取物进行了小鼠最大耐受量测定及小鼠抗生育实验,结果表明,花椒寄生、螃蟹树寄生的醇提取物具有明显抗生育活性,槌果藤也具有一定的抗生育作用。此外,还对槌果藤、野花椒寄生进行了化学成份预试。 相似文献
97.
‘Green tides’ are overwhelming the coastline of our blue planet: taking the world’s largest example 总被引:8,自引:0,他引:8
Nai-hao Ye Xiao-wen Zhang Yu-ze Mao Cheng-wei Liang Dong Xu Jian Zou Zhi-meng Zhuang Qing-yin Wang 《Ecological Research》2011,26(3):477-485
A broad spectrum of events that come under the category of green tide are recognized world-wide as a response to elevated
levels of seawater nutrients in coastal areas. Green tides involve a wide diversity of sites, macroalgal species, consequences,
and possible causes. Here we review the effect of natural and man-induced environmental fluctuations on the frequency and
apparent spread of green tides. This article highlights the need for interdisciplinary research aimed at shedding light on
the basic mechanisms governing the occurrence and succession of green algae in coastal seas. This will result in more effective
management and mitigation of the effects of green tides, thus safeguarding the intrinsic and commercial value of coastal marine
ecosystems. 相似文献
98.
双尾蚜属Diuraphis Aizenberg全世界记录13种,主要分布在古北界和新北界。根据种类丰富度和特有种成分,欧亚大陆的欧洲和中亚为该属蚜虫的现代第一分布中心,北美为第二分布中心。本文提供了该属所有13个种的分种检索表。双尾蚜属蚜虫在中国共有7种,主要分布在蒙新区。它们是:麦双尾蚜Diuraphis noxia (Mordvilko), 害冰麦双尾蚜D. nociva Zhang et Liang,冰草麦蚜D. (Holcaphis) agropyronophaga Zhang, 披碱草蚜D. (Holcaphis) elymophila Zhang, 西方麦蚜D. (Holcaphis) frequens (Walker), 雀麦蚜D. (Holcaphis) bromicola Hille Ris Lambers和绒毛草蚜D. (Holcaphis) holci (Hille Ris Lambers)。对中国种类进行了简要描述。 相似文献
99.
Liang Ma Meixiang Xu Julia R. Forman Jane Clarke Andres F. Oberhauser 《The Journal of biological chemistry》2009,284(47):32942-32949
Mutations in polycystin-1 (PC1) can cause autosomal dominant polycystic kidney disease, which is a leading cause of renal failure. The available evidence suggests that PC1 acts as a mechanosensor, receiving signals from the primary cilia, neighboring cells, and extracellular matrix. PC1 is a large membrane protein that has a long N-terminal extracellular region (about 3000 amino acids) with a multimodular structure including 16 Ig-like polycystic kidney disease (PKD) domains, which are targeted by many naturally occurring missense mutations. Nothing is known about the effects of these mutations on the biophysical properties of PKD domains. Here we investigate the effects of several naturally occurring mutations on the mechanical stability of the first PKD domain of human PC1 (HuPKDd1). We found that several missense mutations alter the mechanical unfolding pathways of HuPKDd1, resulting in distinct mechanical phenotypes. Moreover, we found that these mutations also alter the thermodynamic stability of a structurally homologous archaeal PKD domain. Based on these findings, we hypothesize that missense mutations may cause autosomal dominant polycystic kidney disease by altering the stability of the PC1 ectodomain, thereby perturbing its ability to sense mechanical signals. 相似文献
100.
采用扫描电镜观察了长鳍篮子鱼(Siganus canaliculatus)消化道黏膜上皮表面细微的结构特征。结果显示,长鳍篮子鱼食道黏膜为纵行黏膜褶皱,在褶皱上形成"V"字型次级褶皱,黏膜上皮表面具有许多分泌孔及较多腺体导管的开口,上皮细胞扁平,似鳞片状,连接紧密。胃黏膜褶皱呈绳状纵向排列,黏膜上皮表面有许多沟回,细胞之间有较多的胃小凹,在上皮表面可见有乳头状突起,未见有微绒毛;上皮细胞为五边形或六边形,无细胞间隙。肠黏膜分布着密集排列的肠绒毛,绒毛呈拇指状或扁平状,黏膜上皮表面呈脑回状,分布有许多分泌颗粒,细胞游离面分布着丰富的微绒毛,细胞为多边形、圆形、不规则形,有细胞间隙。幽门盲囊黏膜上皮的结构与肠道相似。本文探讨了黏膜上皮结构与功能的关系。 相似文献