全文获取类型
收费全文 | 2657篇 |
免费 | 327篇 |
出版年
2023年 | 12篇 |
2022年 | 11篇 |
2021年 | 42篇 |
2020年 | 37篇 |
2019年 | 43篇 |
2018年 | 47篇 |
2017年 | 53篇 |
2016年 | 72篇 |
2015年 | 119篇 |
2014年 | 120篇 |
2013年 | 143篇 |
2012年 | 219篇 |
2011年 | 172篇 |
2010年 | 104篇 |
2009年 | 89篇 |
2008年 | 160篇 |
2007年 | 147篇 |
2006年 | 124篇 |
2005年 | 129篇 |
2004年 | 132篇 |
2003年 | 129篇 |
2002年 | 132篇 |
2001年 | 47篇 |
2000年 | 24篇 |
1999年 | 36篇 |
1998年 | 40篇 |
1997年 | 34篇 |
1996年 | 17篇 |
1995年 | 26篇 |
1994年 | 20篇 |
1993年 | 26篇 |
1992年 | 29篇 |
1991年 | 28篇 |
1990年 | 26篇 |
1989年 | 30篇 |
1988年 | 19篇 |
1987年 | 26篇 |
1986年 | 21篇 |
1985年 | 19篇 |
1984年 | 22篇 |
1983年 | 20篇 |
1981年 | 15篇 |
1980年 | 16篇 |
1979年 | 14篇 |
1978年 | 11篇 |
1974年 | 17篇 |
1973年 | 19篇 |
1971年 | 14篇 |
1969年 | 11篇 |
1967年 | 10篇 |
排序方式: 共有2984条查询结果,搜索用时 78 毫秒
1.
A patient with chronic anemia is presented who radiologically showed prominent rugae of the stomach. Angiography demonstrated an arteriovenous malformation with a large feeding artery and prominent draining veins. 相似文献
2.
Infections of one and two Hymenolepis diminuta established in newly weaned rats continued to grow for the duration of the experiment (238 days), whereas infections of 5 worms per rat became asymptotic around Day 55 postinfection and remained at or below this level thereafter as shown by biomass and mean weight per worm measurements. Infections of 50 worms established in newly weaned rats became asymptotic around Day 28 postinfection and thereafter worms were lost from the rats. Initially the biomass fell with the loss of worms, but by Day 56 a new lower biomass persisted for the remainder of the infection period. This level was maintained, despite diminishing numbers of worms, due to the growth of surviving individuals to a weight exceeding the original weight at maturity by a factor of more than 2. Experiments using rats that were mature at the time of infection demonstrated that the same response occurred, but approximately 3 weeks earlier. 相似文献
3.
4.
Sally P Wheatley 《Cell cycle (Georgetown, Tex.)》2015,14(2):261-268
Survivin is a multitasking protein that can inhibit cell death and that is essential for mitosis. Due to these prosurvival activities and the correlation of its expression with tumor resistance to conventional cancer treatments, survivin has received much attention as a potential oncotherapeutic target. Nevertheless, many questions regarding its exact role at the molecular level remain to be elucidated. In this study we ask whether the extreme C- and NH2 termini of survivin are required for it to carry out its cytoprotective and mitotic duties. When assayed for their ability to act as a cytoprotectant, both survivin1–120 and survivin11–142 were able to protect cells against TRAIL-mediated apoptosis, but when challenged with irradiation cells expressing survivin11–142 had no survival advantage. During mitosis, however, removing the NH2 terminal 10 amino acids (survivin11–142) had no apparent effect but truncating 22 amino acids from the C-terminus (survivin1–120) prevented survivin from transferring to the midzone microtubules during anaphase. Collectively the data herein presented suggest that the C-terminus is required for cell division, and that the NH2 terminus is dispensable for apoptosis and mitosis but required for protection from irradiation. 相似文献
5.
6.
7.
Lela Jovanovich Sally Levin M. A. Q. Khan 《Journal of biochemical and molecular toxicology》1987,2(3):203-213
Treatment of rats with mirex (40 ppm in diet) caused hypoglycemia, liver enlargement, and inhibition of adrenal corticosteroid-synthesizing enzyme activity. At toxic dosages (20,000 ppm mirex in diet, which has a lethal toxicity-50 [LT-50] of ten days) poisoned female rats showed severe hypoglycemia, fatty liver, adrenal hyperplasia, hypophagia, lipid mobilization, and body weight (bw) loss. A 50 μg/kg intraperitoneal (IP) dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in male rats caused similar effects two days posttreatment. Hypoglycemia could be overcome by prednisone (which also inhibited adrenocorticoid-synthesizing enzyme activities) but not by streptozotocin treatment, indicating that hypoglycemia may be related to glucocorticoid deficiency resulting from inhibition of their synthesis and not by direct effects on pancreatic β-cells. Glucocorticoid deficiency could also cause increased release of adrenocorticoid hormone (ACTH), which may enhance fat mobilization caused by hypophagia. 相似文献
8.
9.
10.