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   619篇
  免费   53篇
  2023年   3篇
  2022年   7篇
  2021年   9篇
  2020年   12篇
  2019年   9篇
  2018年   11篇
  2017年   15篇
  2016年   27篇
  2015年   34篇
  2014年   33篇
  2013年   41篇
  2012年   53篇
  2011年   51篇
  2010年   27篇
  2009年   15篇
  2008年   43篇
  2007年   41篇
  2006年   25篇
  2005年   27篇
  2004年   35篇
  2003年   24篇
  2002年   33篇
  2001年   2篇
  2000年   3篇
  1999年   9篇
  1998年   11篇
  1997年   7篇
  1995年   3篇
  1994年   5篇
  1993年   5篇
  1992年   1篇
  1991年   4篇
  1990年   5篇
  1989年   3篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1985年   4篇
  1983年   2篇
  1980年   1篇
  1979年   3篇
  1978年   3篇
  1977年   5篇
  1976年   2篇
  1975年   2篇
  1974年   1篇
  1973年   4篇
  1970年   1篇
  1968年   1篇
  1961年   1篇
排序方式: 共有672条查询结果,搜索用时 15 毫秒
1.
This study investigated whether the same cytochrome P-450 (P-450) isoenzymes were inducible in cultures of chick-embryo hepatocytes as in the liver of chicken embryos. We purified two isoenzymes of cytochrome P-450 from the livers of 17-day-old-chick embryos: one of molecular mass approx. 50 kDa induced in vivo by the phenobarbital-like inducer glutethimide, and the second of approx. 57 kDa induced by 3-methylcholanthrene. Rabbit antiserum against the 50 kDa protein inhibited benzphetamine demethylase activity in hepatic microsomes (microsomal fractions) from glutethimide-treated chick embryo. Antiserum to the 57 kDa protein inhibited ethoxyresorufin de-ethylase activity in hepatic microsomes from methylcholanthrene-treated chick embryo. Cultured chick hepatocytes were treated with chemicals known to induce isoenzymes of P-450 in rodent liver. The induced P-450s were quantified spectrophotometrically and characterized by immunoblotting and enzyme assays. From these studies, chemical inducers were classified into three groups: (i) chemicals that induced a P-450 isoenzyme of 50 kDa and increased benzphetamine demethylase activity: glutethimide, phenobarbital, metyrapone, mephenytoin, ethanol, isopentanol, isobutanol, lindane, lysodren; (ii) chemicals that induced a P-450 isoenzyme of 57 kDa and increased ethoxyresorufin de-ethylase activity: 3-methylcholanthrene and 3,3',4,4'-tetrachlorobiphenyl; and (iii) the mono-alpha-substituted 2,3',4,4',5-pentabromobiphenyl, which induced both proteins and both activities. The immunochemical data showed that chick-embryo hepatocytes in culture retain the inducibility of glutethimide- and methylcholanthrene-induced isoenzymes of P-450 that are inducible in the liver of the chicken embryo.  相似文献   
2.
3.
Summary Dehydrocholic acid (3,7,12-trioxo-5-cholanic acid) (0.5% concentration) was completely and selectively reduced to 12-ketoursodeoxycholic acid (3, 7-dihydroxy-12-oxo- 5-cholanic acid) in a membrane reactor by means of 3-hydroxysteroid dehydrogenase and 7-hydroxysteroid dehydrogenase. Coenzyme regeneration was carried out with the glucose-glucose dehydrogenase system.  相似文献   
4.
5.
6.
Wen  Yongdiao  Liu  Shaobin  Zhang  Haifeng  Xu  Yan  Yu  Qiming  Wang  Lingling  Frezza  Fabrizio 《Plasmonics (Norwell, Mass.)》2020,15(4):1141-1149
Plasmonics - Herein, an integrated multifunctional design for simultaneous perfect absorption and polarization conversion is proposed that worked in the Ku band: the proposed structure consisted of...  相似文献   
7.
Molecular Biology Reports - Serine hydrolases play crucial roles in many physiological and pathophysiological processes and a panel of these enzymes are targets of approved drugs. Despite this,...  相似文献   
8.
The aim of this review article is to present, for the first time, an appraisal of the phytochemical, ethnobotanical and pharmacological data on Bunium species. The literature search was conducted using the Scopus, Google Scholar and PubMed databases. The genus Bunium has been found to produce both essential oil (EO), mainly comprising monoterpenes and sesquiterpenes, and non-volatile components mainly coumarins and flavonoids. There are several pharmacological activities associated with the Bunium species, especially antioxidant, antibacterial and antifungal properties. The chemotaxonomic appraisal of the phytochemical pattern of the genus is in sink with the current classification of the family. Moreover, this review confirms the significant ethnobotanical and pharmacological potential of different Bunium species.  相似文献   
9.
The effect of omeprazole on the mitochondrial carnitine/acylcarnitine transporter has been studied in proteoliposomes. Externally added omeprazole inhibited the carnitine/carnitine antiport catalysed by the transporter. The inhibition was partially reversed by DTE indicating that it was caused by the covalent reaction of omeprazole with Cys residue(s). Inhibition of the C-less mutant transporter indicated also the occurrence of an alternative non-covalent mechanism. The IC50 of the inhibition of the WT and the C-less CACT by omeprazole were 5.4 µM and 29 µM, respectively. Inhibition kinetics showed non competitive inhibition of the WT and competitive inhibition of the C-less. The presence of carnitine or acylcarnitines during the incubation of the proteoliposomes with omeprazole increased the inhibition. Using site-directed Cys mutants it was demonstrated that C283 and C136 were essential for covalent inhibition. Molecular docking of omeprazole with CACT indicated the formation of both covalent interactions with C136 and C283 and non-covalent interactions in agreement with the experimental data.  相似文献   
10.
Oxidative stress is considered the common effector of the cascade of degenerative events in many neurological conditions. Thus, in this paper we tested different nutraceuticals in H2O2 in vitro model to understand if could represent an adjuvant treatment for neurological diseases. In this study, nutraceuticals bacopa, lycopene, astaxanthin, and vitamin B12 were used alone or in combination in human neuronal differentiated SH-SY5Y cells upon hydrogen peroxide-induced injury and neuroprotective, neuronal death pathways were analyzed. The nutraceuticals analyzed were able to protect H2O2 cytotoxic effects, through increasing cell viability and proteins involved in neuroprotection pathways and restoring proteins involved in cell death pathways. On this basis, it is possible to propose the use of these compounds as dietary supplement for the prevention or as adjuvant to the only symptomatic treatments so far available for neurodegenerative diseases.  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