全文获取类型
收费全文 | 2150篇 |
免费 | 123篇 |
国内免费 | 3篇 |
专业分类
2276篇 |
出版年
2022年 | 11篇 |
2021年 | 21篇 |
2020年 | 16篇 |
2019年 | 18篇 |
2018年 | 29篇 |
2017年 | 25篇 |
2016年 | 51篇 |
2015年 | 68篇 |
2014年 | 62篇 |
2013年 | 131篇 |
2012年 | 128篇 |
2011年 | 115篇 |
2010年 | 99篇 |
2009年 | 81篇 |
2008年 | 129篇 |
2007年 | 126篇 |
2006年 | 109篇 |
2005年 | 116篇 |
2004年 | 131篇 |
2003年 | 119篇 |
2002年 | 114篇 |
2001年 | 49篇 |
2000年 | 48篇 |
1999年 | 46篇 |
1998年 | 19篇 |
1997年 | 22篇 |
1996年 | 10篇 |
1995年 | 11篇 |
1994年 | 13篇 |
1993年 | 9篇 |
1992年 | 30篇 |
1991年 | 34篇 |
1990年 | 23篇 |
1989年 | 24篇 |
1988年 | 27篇 |
1987年 | 16篇 |
1986年 | 26篇 |
1985年 | 12篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 14篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1976年 | 12篇 |
1974年 | 9篇 |
1971年 | 12篇 |
1969年 | 10篇 |
排序方式: 共有2276条查询结果,搜索用时 0 毫秒
11.
12.
13.
14.
Seko T Kato M Kohno H Ono S Hashimura K Takimizu H Nakai K Maegawa H Katsube N Toda M 《Bioorganic & medicinal chemistry letters》2001,11(16):2067-2070
The synthesis and structure-activity relationship (SAR) study of a novel series of N-type calcium channel blockers are described. L-Cysteine derivative 2a was found to be a potent and selective N-type calcium channel blocker with IC(50) 0.63 microM on IMR-32 assay. Compound 2a showed analgesic efficacy in the rat formalin-induced pain model by intrathecal and oral administration. 相似文献
15.
Purification, subunit structure, and partial amino acid sequence of metapyrocatechase 总被引:12,自引:0,他引:12
C Nakai K Hori H Kagamiyama T Nakazawa M Nozaki 《The Journal of biological chemistry》1983,258(5):2916-2922
16.
17.
Tsukamoto H Hishinuma T Suzuki N Tayama R Hiratsuka M Yoshihisa T Mizugaki M Goto J 《Prostaglandins & other lipid mediators》2004,73(3-4):191-213
Thiazolidinedione, peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, has been used as an anti-diabetic drug and as an useful tool to elucidate multiple PPARgamma functions by in vitro and in vivo studies. We investigated the effects of thiazolidinediones on prostanoid production in lipopolysaccharide-stimulated cells. The high concentrations (>10 microM) of rosiglitazone and pioglitazone significantly increased lipopolysaccharide-stimulated prostanoid production such as thromboxane A2 and prostaglandin E2. However, PPARgamma antagonist could not inhibit them. In PPARgamma-deficient cells, thiazolidinediones increased prostaglandin E2 production. Thiazolidinediones increased arachidonic acid (AA) release from the cell membrane by not stimulating AA releasing process involving several phospholipase A2s but inhibiting AA reuptaking process. The expression of cyclooxygenase-1 and cyclooxygenase-2 were not affected by thiazolidinediones. In this study, we demonstrated that high concentrations of TZDs increased AA release by the inhibition of AA reuptaking process, leading to subsequent increase in the prostanoid production in a PPARgamma-independent manner. This mechanism provides useful information for the elucidation of multiple PPARgamma functions and diabetic drug therapy. 相似文献
18.
Aldose reductase inhibitors: flavonoids, alkaloids, acetophenones, benzophenones, and spirohydantoins of chroman 总被引:3,自引:0,他引:3
The inhibitory activity of various compounds, including 12 flavonoids, 10 alkaloids, 15 benzophenones, 5 acetophenones, and 7 spirohydantoins of chroman, was tested on rabbit lens aldose reductase, an enzyme involved in complications of diabetes. Almost all compounds tested were found to inhibit the enzyme at low concentrations (10(-5) M). The most potent inhibitor was 2R,4S-6-chloro-2-methylspiro(chroman-4,4'-imidazo-lidine+ ++)-2',5'-dione with an I50 value of 4.7 x 10(-8) M; other spirohydantoins showed similar potency. Polyhydroxybenzophenones were also potent inhibitors with an I50 value of about 10(-7) M. The possible structure-inhibitory activity relationships of the compounds tested are discussed. 相似文献
19.
Ramachandran Prakasam Mitsuaki Fujimoto Ryosuke Takii Naoki Hayashida Eiichi Takaki Ke Tan Fangxu Wu Sachiye Inouye Akira Nakai 《FEBS letters》2013
The febrile response is elicited by pyrogenic cytokines including IL-6 in response to microorganism infections and diseases in vertebrates. Mammalian HSF1, which senses elevations in temperature, negatively regulates the response by suppressing pyrogenic cytokine expression. We here showed that HSF3, an avian ortholog of mammalian HSF1, directly binds to and activates IL-6 during heat shock in chicken cells. Other components of the febrile response mechanism, such as IL-1β and ATF3, were also differently regulated in mammalian and chicken cells. These results suggest that the febrile response is exacerbated by a feed-forward circuit composed of the HSF3-IL-6 pathway in birds. 相似文献
20.
Kazushi Yukiiri Naohisa Hosomi Takayuki Naya Tsutomu Takahashi Hiroyuki Ohkita Mao Mukai Hisashi Masugata Koji Murao Masaki Ueno Takehiro Nakamura Hiroaki Dobashi Takanori Miki Yasuhiro Kuroda Masakazu Kohno 《BMC neurology》2008,8(1):1-8