首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   36篇
  免费   1篇
教育   21篇
科学研究   14篇
综合类   1篇
信息传播   1篇
  2022年   1篇
  2017年   1篇
  2016年   1篇
  2014年   2篇
  2013年   4篇
  2012年   3篇
  2011年   3篇
  2009年   4篇
  2008年   2篇
  2007年   4篇
  2006年   2篇
  2005年   2篇
  2004年   1篇
  2003年   2篇
  2000年   3篇
  1994年   1篇
  1989年   1篇
排序方式: 共有37条查询结果,搜索用时 97 毫秒
1.
Infertility is well-established harmful effect in chronic alcoholism and so far, there is no effective treatment for this condition. The study was conducted to determine the effects of alpha tocopherol on ethanol induced testicular injuries in male albino rats of Wistar strain. Five groups (n=6) of animals were used. Group I served as control. Group II received daily 1.6g ethanol/kg body weight/day for 4 weeks orally. Group III received 1.6g ethanol+80mg alpha tocopherol/kg body weight/day for four weeks orally. Group IV received 1.6g ethanol/kg body weight for/day 4 weeks and followed by 80mg alpha tocopherol/kg body weight/day for four weeks orally. Group V received 1.6g ethanol/kg body weight/day orally for 4 weeks, followed by 4 weeks abstinence. Twently-four hours after the last treatment the rats were sacrificed using anesthetic ether. Testes were removed and used for the estimation of extent of lipid peroxidation and tissue levels of antioxidants and steroidogenic enzymes. Alpha tocopherol treatment increased the activities of testicularΔ 5, 3β-HSD. Moreover, the treatment was also associated with significant decrease in testicular oxidative stress. Ethanol-induced oxidative stress and decreased steroidogenesis can be reversed by treatment with alpha tocopherol.  相似文献   
2.
拥有大客户资源既可能表征企业的高质量发展,也可能传递企业的高经营风险信息。本文以2007—2018年A股上市公司为样本,从审计师发表持续经营审计意见(GCO)的视角,研究了企业大客户资源效应的信号传递价值。结果发现,较高的客户集中度会降低企业持续经营能力,审计师将其评估为高风险审计事项,提高了发表GCO的概率。进一步分析发现当企业失去大客户风险较低、大客户财务困境风险较小或者企业自身议价能力较强时,大客户集中度对审计师发表GCO概率的正向影响有所减弱。此外本文还发现大客户集中度引致的风险价值信息并非由于其监督动机不足所致。本文研究丰富了审计意见影响因素和客户集中度经济后果方面的相关文献。  相似文献   
3.
In paper conservation ethanol is used as an antifungal agent. However, information on the antifungal efficacy of this alcohol is scarce and often inconsistent. In this study, we clarify if ethanol is effective and safe to use in paper conservation in the short as well as in the long term. None of the tested ethanol concentrations (5–100%) promoted conidia germination, but rather delayed or entirely inhibited it, depending on alcohol concentration and contact time. In a simulation of an interventive treatment of samples colonized by fungi, all the tested ethanolic solutions (30, 70, and 100%) revealed antifungal activity. The best results were obtained with 70% ethanol, showing fungicidal properties on four of the five-tested fungal species (Aspergillus niger, Cladosporium cladosporioides, Penicillium chrysogenum, and Penicillium corylophilum). No deleterious effects of 70% ethanol on the tested paper were observed either in the short or in the long term.  相似文献   
4.
Several models of experimental ulcerative colitis have been reported previously. However, none of these models showed the optimum characteristics. Although dextran sulfate sodium-induced colitis results in inflammation resembling ulcera-tive colitis, an obvious obstacle is that dextran sulfate sodium is very expensive. The aim of this study was to develop an inex-pensive model of colitis in rats. Sprague-Dawley rats were treated with 2% dextran sulfate sodium in drinking water for 3 d fol-lowed by an intracolonic administration of 30% ethanol. The administration of 2% dextran sulfate sodium followed by 30% ethanol induced significant weight loss, diarrhea and hematochezia in rats. Severe ulceration and inflammation of the distal part of rat colon were developed rapidly. Histological examination showed increased infiltration of polymorphonuclear leukocytes, lymphocytes and existence of cryptic abscesses and dysplasia. The model induced by dextran sulfate sodium at lower concentra-tion followed by 30% ethanol is characterized by a clinical course, localization of the lesions and histopathological features similar to human ulcerative colitis and fulfills the criteria set out at the beginning of this study.  相似文献   
5.
In the current study, we report perturbations in hepatic, renal and splenic heme synthesis at the level of the rate limiting enzyme, δ-amino levulinic acid synthase (ALA-S) on ethanol administration independently and in conjunction with iron-protoporphyrin (FePP) in male Wistar rats. Excessive ethanol administration (5 ml/kg bw) resulted in a significant induction of hepatic, splenic and renal ALA-S activity. Simultaneous administration of FePP (50 μmol/kg bw) reverted the observed induction response to a sharp decline. The features of the action of ethanol and FePP togetherin vivo, i.e. a substantial inhibition of ALA-S is suggestive of the beneficial effects of this formulation in acute attacks of porphyria.  相似文献   
6.
为评估降雨路面径流汞(Hg)污染状况,对南京绕城高速公路马群段11场降雨路面径流进行了监测,分析了汞(Hg)的事件平均浓度(EMC)以及降雨特性对径流中Hg污染的影响.结果表明,不同赋存状态的Hg的污染程度均较为严重,总Hg(THg)、溶解态汞(HgD)和颗粒态汞(HgP)含量分别为0.173~3.347,0.069~0.862和0.104~2.485μg/L.THg的EMC超过了中国《地表水环境质量标准(GB 3838—2002)》中5类水的限值.雨水径流中Hg主要以颗粒态存在,络合态Hg(Hgre,0.250~2.821μg/L)的含量远大于挥发性Hg(Hg0,0.023~0.215μg/L)和活性Hg(Hg2+,0.026~0.359μg/L).各种降雨特性对径流中Hg污染的影响顺序为前期晴天数径流时间降雨历时降雨强度降雨量.  相似文献   
7.
针刺对运动性疲劳大鼠性激素水平和性腺结构的影响   总被引:4,自引:0,他引:4  
运动性疲劳可引起下丘脑-垂体-性腺(HPG)轴功能失调,采用针刺穴位刺激方法,观察对疲劳状态下大鼠性激素水平和性腺结构的影响,实验结果表明,疲劳针刺组血浆T浓度明显高于疲劳组(P<0.01),血浆LH比较, 疲劳针刺组明显高于疲劳组和正常组(P<0.05);睾丸超微结构疲劳针刺组与正常组基本相似,但疲劳组出现间质细胞数量少,线粒体及内质网有溶解现象;腺垂体LH细胞结构在各组中大体相同.  相似文献   
8.
Aluminum and alcohol, both are well-accepted neurotoxin. The plausible mechanisms for their neurotoxicity are also common. Therefore, the effect of ethanol on aluminum induced biochemical changes in rat brain is being studied. In the present study, ethanol exposure significantly affected the aluminum and protein content of brain. The activities of acid phosphatase and alkaline phosphatase were also changed. Aluminum exposure, on the other hand, contributed significantly in the alterations of aluminum content, acid phosphatase acivity and aspartate aminotransferase activity. Though ethanol co-exposure significantly influenced the aluminum load of brain, the interactions of these two neurotoxins were found to be significant only in case of acid phosphatase activity of brain. Therefore, it can be suggested that general neurotoxicity produced by aluminum is not modified by ethanol. However, the aluminum load caused by aluminum exposure, may be influenced by ethanol co-exposure.  相似文献   
9.
Damaging effects of reactive oxygen species on living systems are well documented. They include oxidative attack on vital cell constituents. Chronic ethanol administration is able to induce an oxidative stress in the central nervous system. In the present study, 16–18 week-old male albino rats of Wistar strain were exposed to different concentration of ethanol for 4 weeks. This exposure showed profound effect on body weight. Ascorbic acid level; and activities of alkaline phosphatase and aspartate transaminase in the brain are dependent on the concentration of ethanol exposure. Chronic ethanol ingestion elicits statistically significant increase in thiobarbituric acid reactive substances level and decrease in gluatathione level in the brain. It reduces superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities in a dose dependent manner. However, histological examination could not reveal any pathophysiological changes. Therefore, we conclude that biochemical alterations and oxidative stress related parameters respond early in alcoholism than the histopathological changes in brain.  相似文献   
10.
本文采用电解技术对高浓度氨氮废水进行处理研究,考察电化学方法对废水中高浓度氨氮的去除效果,并优化其工艺参数。结果表明,电流密度、Cl^-1浓度、极板对数等均对高浓度氨氮的电解处理效率有直接影响;综合考虑电耗、投加Cl^-1量等经济因素和处理效果,其优化工艺参数为8A电流、NH4^+与Cl^-1的摩尔比为1:4、2对极板;此条件下氨氮的90m in去除率为81.5%,电耗为63.6度。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号