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   218篇
  免费   16篇
  国内免费   1篇
  2023年   2篇
  2022年   2篇
  2021年   3篇
  2020年   2篇
  2019年   2篇
  2018年   11篇
  2017年   16篇
  2016年   13篇
  2015年   4篇
  2014年   14篇
  2013年   25篇
  2012年   21篇
  2011年   23篇
  2010年   8篇
  2009年   5篇
  2008年   17篇
  2007年   15篇
  2006年   11篇
  2005年   3篇
  2004年   6篇
  2003年   7篇
  2002年   5篇
  2001年   1篇
  2000年   1篇
  1997年   3篇
  1996年   5篇
  1995年   3篇
  1991年   1篇
  1988年   2篇
  1982年   1篇
  1977年   2篇
  1976年   1篇
排序方式: 共有235条查询结果,搜索用时 541 毫秒
231.
Aminoglycoside antibiotics such as gentamicin are used frequently to treat bacterial infections in humans. Excessive consumption of these antibiotics lead to renal dysfunction. One of the factors contributing to renal dysfunction is oxidative damage, which causes apoptosis. Hence, this study investigates the effect of the antioxidant compound deacetyl epoxyazadiradione (DEA) in reducing cell death induced by gentamicin treatment in kidney cells (Madin–Darby canine kidney cells). The antioxidant experiments showed that reactive oxygen species level is decreased up to 27.06 ± 0.18% in 150 µM of DEA treatment. At this concentration, the activity of antioxidant enzymes such as superoxide dismutase increased from 0.4 ± 0.04 to 1.46 ± 0.05 µmol/min/L and catalase increased from 7.48 ± 0.39 to 17.6 ± 0.74 U/mg. The relative folds of gene expression of mitochondrial enzymes such as GST, GPx and GR restored from 0.596 ± 0.019, 0.521 ± 0.013 and 0.775 ± 0.014 to 0.866 ± 0.013, 0.669 ± 0.015 and 0.8615 ± 0.028, respectively. Consequently, the percentage of cell viability increases upto 91.8 ± 2.01 from 61.93 ± 1.63 with much less fragmentation in genomic DNA. Additionally, molecular docking results showed that DEA could bind to Bax, Bcl- 2, Caspase- 3 and Caspase- 9 proteins. These results indicate that DEA could reduce cell apoptosis by reducing oxidative stress due to antibiotics and interrupting the apoptotic signal pathway in kidney cells.  相似文献   
232.
As the use of various anticancer drugs is associated with many undesirable side effects, there is an urgent need for the discovery of new, better, and specific anticancer compounds. Antioxidant and antiproliferative activities as well as effects on cell morphology were investigated for methanol (M), chloroform (C), ethyl acetate (E), and aqueous (A) extracts of Caulerpa peltata, Gelidiella acerosa, Padina gymnospora, and Sargassum wightii using 2,2-diphenyl-1-picrylhydrazyl radical-scavenging, ferrous ion chelation, and resazurin-based growth inhibition (in A549, HCT-15, MG-63, and PC-3 cell lines) assays. A general trend was the greater extraction of phenols and flavonoids by chloroform and ethyl acetate, which showed higher activity in many assays. These non-polar C and E extracts showed higher DPPH radical-scavenging and growth inhibitory activities in A549, HCT-15, and PC-3 cells. However, higher ferrous ion chelation (A extracts) and growth inhibition in MG-63 cells (M and A extracts) were seen for the polar extracts. Furthermore, P. gymnospora and C. peltata emerged as promising sources for antiproliferative agents that could be explored for their own activity and as leads for the development of other compounds.  相似文献   
233.
Two forms (here called short and long) of the tadpole shrimp Triops from the Baja California peninsula (Mexico) exhibit interesting features for aquacultural purposes; rapid growth, early maturation (six days) and uniparental reproduction via cysts (i.e. drought-resistant dormant eggs). The use of Triops for aquaculture depends on the standard production of viable cysts. Basic information on the reproductive potential of Triops is scarce. Using a recirculating system, we studied, through two culture tests, the cyst production, frequency of molting, and growth rate of the two Mexican forms. For each form, individual data were obtained from five specimens in Test 1 over 15 days, and from 10 specimens in Test 2 over 20 days. Hatching response of cysts produced in Test 1 was also studied. The short-form showed a high fecundity depositing groups of cysts from the ovisacs several times a day. The mean cyst production per day was 156–306 (Test 1 & 2), and the mean total cyst production was 2028 (range 728–3193) (Test 1), and 5821 (range 4136–7554) (Test 2). The maximum number of cysts deposited by one short-form individual in a day was 1231 (Test 2). The reproductive performance of the long-form was poor. The mean cyst production per day was only 4.2–7.9 (Test 1 & 2). The short-form molted every 2.5–2.8 days and the long-form molted every 2.8–3.7 days. The mean growth rate calculated from the standard length (mm d–1) of the short-form was 0.43–0.84 (Test 1 & 2), and in the long-form the values were 0.84–1.25 (Test 1 & 2). The poor cyst production of the long-form may be explained by inadequate food resources that did not fulfill the nutritional requirements for reproduction. Given its prolific uniparental reproduction (vs. biparental reproduction), the short-form Triops appears as a good potential candidate for aquaculture.  相似文献   
234.
Chitin was assayed in adults of nine anostracan species (Streptocephalus dichotomus, S. proboscideus, S. simplex, S. torvicornis, Thamnocephalus platyurus, Dendrocephalus brasiliensis, Chirocephalus diaphanus, Artemia salina and Branchipus schaefferi) using a highly specific enzymatic method. Cysts of A. salina, T. platyurus and larvae of A. salina and S. simplex were also analysed for their chitin content. The results demonstrated a weak interspecific variation in chitin content among the adults. On the whole, it ranged from 9 to 33 mg chitin (g dry mass)−1. In most species, the chitin level was not significantly different between males and females. In contrast, chitin levels varied significantly between cysts, larvae and adults within species. Comparison of the chitin content of anostracans revealed a comparable or lower chitin level than other crustaceans. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
235.
We identified and quantified the major inorganic ions present in a haemolymph of four species of fairy shrimp, to determine its ionic strength, using capillary electrophoresis, non-destructive micro-technique for the analysis of small amounts of body fluids. This is the first speciation and quantitative analysis of inorganic ions in the haemolymph of fairy shrimps.  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