全文获取类型
收费全文 | 324987篇 |
免费 | 29322篇 |
国内免费 | 283篇 |
出版年
2018年 | 3605篇 |
2017年 | 3450篇 |
2016年 | 4659篇 |
2015年 | 5161篇 |
2014年 | 6320篇 |
2013年 | 9025篇 |
2012年 | 9885篇 |
2011年 | 10559篇 |
2010年 | 7324篇 |
2009年 | 6482篇 |
2008年 | 9284篇 |
2007年 | 9482篇 |
2006年 | 8978篇 |
2005年 | 8524篇 |
2004年 | 8380篇 |
2003年 | 8170篇 |
2002年 | 7881篇 |
2001年 | 15476篇 |
2000年 | 15312篇 |
1999年 | 11750篇 |
1998年 | 3566篇 |
1997年 | 3666篇 |
1996年 | 3514篇 |
1995年 | 3226篇 |
1994年 | 3145篇 |
1993年 | 3044篇 |
1992年 | 9199篇 |
1991年 | 8974篇 |
1990年 | 9061篇 |
1989年 | 8642篇 |
1988年 | 8065篇 |
1987年 | 7645篇 |
1986年 | 6883篇 |
1985年 | 7193篇 |
1984年 | 5713篇 |
1983年 | 4968篇 |
1982年 | 3485篇 |
1981年 | 3258篇 |
1980年 | 3004篇 |
1979年 | 5380篇 |
1978年 | 4131篇 |
1977年 | 3776篇 |
1976年 | 3678篇 |
1975年 | 4274篇 |
1974年 | 4591篇 |
1973年 | 4716篇 |
1972年 | 4098篇 |
1971年 | 3764篇 |
1970年 | 3367篇 |
1969年 | 3149篇 |
排序方式: 共有10000条查询结果,搜索用时 819 毫秒
951.
952.
953.
954.
955.
956.
Bacterial oxidation of polythionates: determination of tetrathionate with an ion-selective electrode.
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A commercially available ion-selective electrode for nitrate was used to continuously monitor tetrathionate oxidation by Thiobacillus dentrificans. The electrode was much more sensitive to tetrathionate than to nitrate. The same electrode could also be used for the determination of trithionate. 相似文献
957.
958.
959.
Saphenous vein ligation and stripping was performed on 27 patients in the immediate postpartum period without complications. Doing the operation at this time saves time and money. Technically it is easier to do postpartum than during pregnancy, and the patients have less postoperative discomfort than is usual with phlebectomy at other times. 相似文献
960.
William P. Sullivan David F. Smith Thomas G. Beito Christopher J. Krco David O. Toft 《Journal of cellular biochemistry》1988,36(2):103-119
Avian progesterone receptor exists as two forms, A and B, with molecular weights of 79,000 and 110,000 daltons, respectively. The origin and significance of these two forms is an area of active investigation and debate. Monoclonal antibodies produced against these two forms were used to examine receptor stability in cytosol and changes in the receptor forms induced by hormone binding. The lability of hormone binding at elevated temperatures is well documented. Analysis by Western blotting showed the receptor was stable in freshly prepared oviduct cytosol for 2 hr at 37°C, while hormone binding was lost within 30 min. However, loss of receptor through degradation was seen when cytosol was prepared from frozen tissue or when homogenization was excessive. Progesterone was injected into diethylstilbestrol-stimulated chicks to examine, in vivo, effects of hormone treatment on receptor forms in the cytosol and nuclear fractions. Progesterone treatment caused a time- and dose-dependent conversion of the A receptor to a form (A′) with a slower electrophoretic mobility. The cytosolic progesterone receptor was divided equally between the B and A forms, while the nuclear receptor was predominantly A′. The amount of nuclear receptor was consistently less than cytosolic receptor. Receptor phosphorylation was analyzed by incubating tissue minces with [32P]orthophosphate with or without progesterone followed by immune isolation of receptor forms. Progesterone treatment caused a time-dependent increase in cytosol receptor phosphorylation which was evident after 5 min of treatment. This phosphorylation was observed with both the A and B receptor forms. The results indicate that receptor phosphorylation is a very early event during progesterone action. 相似文献