全文获取类型
收费全文 | 2085篇 |
免费 | 115篇 |
国内免费 | 1篇 |
专业分类
2201篇 |
出版年
2022年 | 13篇 |
2021年 | 29篇 |
2020年 | 17篇 |
2019年 | 10篇 |
2018年 | 30篇 |
2017年 | 33篇 |
2016年 | 39篇 |
2015年 | 66篇 |
2014年 | 76篇 |
2013年 | 102篇 |
2012年 | 122篇 |
2011年 | 134篇 |
2010年 | 77篇 |
2009年 | 88篇 |
2008年 | 117篇 |
2007年 | 143篇 |
2006年 | 134篇 |
2005年 | 130篇 |
2004年 | 124篇 |
2003年 | 130篇 |
2002年 | 111篇 |
2001年 | 28篇 |
2000年 | 38篇 |
1999年 | 30篇 |
1998年 | 37篇 |
1997年 | 37篇 |
1996年 | 19篇 |
1995年 | 22篇 |
1994年 | 15篇 |
1993年 | 16篇 |
1992年 | 26篇 |
1991年 | 22篇 |
1990年 | 17篇 |
1989年 | 17篇 |
1988年 | 14篇 |
1987年 | 15篇 |
1986年 | 24篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1969年 | 2篇 |
排序方式: 共有2201条查询结果,搜索用时 10 毫秒
181.
Participation of hup gene product in ori2-dependent replication of fertility plasmid F 总被引:3,自引:0,他引:3
The fertility plasmid F'gal was not stably maintained in a hupA-hupB double mutant of Escherichia coli. Moreover, mini-F plasmids pFZY1, pFTC1 and pFTC2 were unable to transform the double mutant, though these plasmids efficiently transformed cells harboring a hupA or hupB single mutation. The composite plasmid pFHS1, which consists of the f5 DNA fragment of F plasmid and the whole DNA of a pSC101 derivative that carries a temperature-sensitive mutation for DNA replication, was not stably maintained in the hup double mutant at 42°C. These findings strongly suggest that HU protein is required for ori2-dependent replication of the F plasmid. 相似文献
182.
ATF4-mediated induction of 4E-BP1 contributes to pancreatic beta cell survival under endoplasmic reticulum stress 总被引:1,自引:0,他引:1
183.
184.
Dong Y Nakagawa-Goto K Lai CY Morris-Natschke SL Bastow KF Lee KH 《Bioorganic & medicinal chemistry letters》2011,21(8):2341-2344
4-Amino-2H-benzo[h]chromen-2-one (ABO) and 4-amino-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (ATBO) analogs were found to be significant in vitro anticancer agents in our previous research. Our continuing study has now discovered a new simplified (monocyclic rather than tricyclic) class of cytotoxic agents, 4-amino-2H-pyran-2-one (APO) analogs. By incorporating various substituents on the pyranone ring, we have established preliminary structure-activity relationships (SAR). Analogs 19, 20, 23, and 26-30 displayed significant tumor cell growth inhibitory activity in vitro. The most active compound 27 exhibited ED50 values of 0.059-0.090 μM. 相似文献
185.
186.
F Furuyama Y Ishida M Furuyama T Hashitani Y Isobe H Sato K Ohara H Nishino 《Comp. Biochem. Physiol. C, Comp. Pharmacol. Toxicol.》1989,94(1):133-138
1. The relationship between thermal salivation (TS) and thermoregulation was studied in anesthetized rats. 2. Of the 6 anesthetics used, ketamine-anesthetized rats secreted the largest amount of saliva. Salivation, however, was thermal and not induced by ketamine itself. 3. Ketamine-anesthetized rats readily secreted saliva at core temperatures less than 40 degrees C but TS was remarkably enhanced by hyperthermia of 40-42.5 degrees C. 4. The equilibrium phase in the triphasic heat response of core temperature was a consequence of equilibrium between heat gain and heat loss by salivation. 相似文献
187.
188.
Kyoko Saio Masahiro Kajikawa Tokuji Watanabe 《Bioscience, biotechnology, and biochemistry》2013,77(6):890-898
Relation between sulfhydryl groups in soybean proteins and the physical properties of tofu was studied. Changes in the amount of sulfhydryl groups by heating or treatment with urea were more rapid in 11S protein as compared with 7S protein. Moreover, by changing the amount of sulfhydryl groups in proteins by N-ethylmaleimide, 2-mercapto-ethanol and dithiothreitol, the physical properties of tofu from 11S protein were more significantly effected than that from 7S protein. Namely, tofu-gel from 11S. protein got harder and stronger as the amount of sulfhydryl groups increased.The results may suggest that tofu prepared from IIS protein has more disulfide bonds in its gel than that from 7S protein. 相似文献
189.
190.