首页 | 官方网站   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   28276篇
  免费   1867篇
  国内免费   277篇
医药卫生   30420篇
  2023年   211篇
  2022年   735篇
  2021年   1091篇
  2020年   589篇
  2019年   808篇
  2018年   951篇
  2017年   750篇
  2016年   1109篇
  2015年   1504篇
  2014年   1579篇
  2013年   1882篇
  2012年   2708篇
  2011年   2508篇
  2010年   1522篇
  2009年   1200篇
  2008年   1656篇
  2007年   1459篇
  2006年   1252篇
  2005年   1179篇
  2004年   939篇
  2003年   830篇
  2002年   679篇
  2001年   406篇
  2000年   390篇
  1999年   311篇
  1998年   143篇
  1997年   125篇
  1996年   85篇
  1995年   68篇
  1994年   71篇
  1993年   64篇
  1992年   112篇
  1991年   130篇
  1990年   111篇
  1989年   97篇
  1988年   90篇
  1987年   76篇
  1986年   78篇
  1985年   62篇
  1984年   42篇
  1983年   38篇
  1979年   53篇
  1978年   37篇
  1975年   52篇
  1974年   29篇
  1972年   39篇
  1971年   49篇
  1970年   34篇
  1969年   27篇
  1968年   31篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.

Background

To investigate the prognostic significance of altered breast cancer susceptibility gene 1 (BRCA1) and p53 expression in triple-negative breast cancer (TNBC).

Methods

Immunohistochemical expression of BRCA1 and p53 was examined in the tumor tissues of 465 TNBC cases and relations were sought with clinicopathological features and patient survival.

Results

Loss of BRCA1 expression was found in 29.5% (137/465) of TNBCs. Positive expression of p53 was observed in 49.9% (232/465). Patients with loss of BRCA1 expression had a tendency to have higher rate of lymph node metastasis (p = 0.075). An association between p53 expression and high histological grade was observed (p = 0.039). TNBC patients with loss of BRCA1 expression had a tendency to have poorer overall survival (OS) than those positive for BRCA1 (p = 0.09). TNBC patients with positive p53 expression showed better OS than those with p53 negativity (p = 0.001). In terms of combined expression patterns, significantly poorer overall survival (OS) was observed for BRCA1-negative/p53-negative TNBCs and best OS for BRCA1-positive/p53-positive TNBCs (p = 0.005).

Conclusions

Combined expression patterns of BRCA1 and p53 could serve as useful prognostic markers in TNBC.
  相似文献   
992.

Background

Despite reported effectiveness, weight loss surgery (WLS) still remains one of the least preferred options for outpatient providers, especially in Germany. The aim of this study was to examine the effect of stigma and knowledge on recommendation of WLS and referral to a surgeon by general practitioners (GPs) and internists.

Method

The sample consists of 201 GPs and internists from Germany. The questionnaire included questions on the perceived effectiveness of WLS, the frequency of recommendations of WLS, and the frequency of referral to WLS. Stigma, as well as knowledge was also assessed in this context. Linear and logistic regression models were conducted. A mediation analysis was carried out within post hoc analysis.

Results

Knowledge (b?=?0.258, p?<?0.001) and stigma towards surgery (b?=??0.129, p?=?0.013) were related to the frequency of recommendation of WLS. Additionally, respondents, who were more likely to express negative attitudes towards WLS, were less likely to recommend WLS and thus refer patients to WLS (b?=??0.107, p?<?0.05). Furthermore, respondents with more expertise on WLS were more likely to recommend and thus refer patients to WLS (b?=?0.026, p?<?0.05).

Conclusion

This study showed that stigma plays a role when it comes to defining treatment pathways for patients with obesity. The question remains how this might influence the patients and their decision regarding their treatment selection. Interventions are required to make treatment decisions by physicians or patients independent of social pressure due to stigma.
  相似文献   
993.
994.
995.
996.
997.
998.
Vinay DS  Choi JH  Kim JD  Choi BK  Kwon BS 《Immunology》2007,122(3):394-400
Systemic lupus erythematosus (SLE) is characterized by the production of autoantibodies directed against nuclear antigens including nucleosomes and DNA. To determine the role of T-cell costimulatory molecule 4-1BB in the regulation of SLE, MRL-Fas(lpr) (lpr) mice deficient in 4-1BB (lpr/4-1BB(-/-)) were generated and their disease phenotype was compared to that of control lpr mice. The main finding of this study is that the lpr/4-1BB(-/-) mice had more pronounced skin lesions which appeared earlier, increased lymphadenopathy, increased renal damage, and higher mortality than 4-1BB-intact control lpr mice. The increased severity of lesions in lpr/4-1BB(-/-) mice was closely associated with increases in CD4(+) T, CD3(+) B220(+) double-negative T cells, serum immunoglobulin, anti-dsDNA autoantibodies, and tissue immunoglobulin deposits. These data suggest that the 4-1BB-4-1BB ligand signalling pathway plays an important role in SLE and that deletion of 4-1BB confers susceptibility to lpr mice, leading to accelerated induction of disease and early mortality.  相似文献   
999.
1000.
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-23

京公网安备 11010802026262号