首页 | 本学科首页   官方微博 | 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   5473篇
  免费   360篇
  国内免费   42篇
耳鼻咽喉   88篇
儿科学   208篇
妇产科学   65篇
基础医学   551篇
口腔科学   100篇
临床医学   453篇
内科学   1080篇
皮肤病学   147篇
神经病学   322篇
特种医学   258篇
外国民族医学   1篇
外科学   900篇
综合类   138篇
一般理论   6篇
预防医学   319篇
眼科学   148篇
药学   664篇
中国医学   40篇
肿瘤学   387篇
  2023年   44篇
  2022年   157篇
  2021年   203篇
  2020年   110篇
  2019年   144篇
  2018年   178篇
  2017年   105篇
  2016年   154篇
  2015年   148篇
  2014年   188篇
  2013年   261篇
  2012年   382篇
  2011年   352篇
  2010年   209篇
  2009年   186篇
  2008年   300篇
  2007年   301篇
  2006年   274篇
  2005年   252篇
  2004年   222篇
  2003年   209篇
  2002年   168篇
  2001年   131篇
  2000年   114篇
  1999年   108篇
  1998年   51篇
  1997年   46篇
  1996年   50篇
  1995年   51篇
  1994年   41篇
  1993年   53篇
  1992年   74篇
  1991年   73篇
  1990年   56篇
  1989年   53篇
  1988年   55篇
  1987年   37篇
  1986年   35篇
  1985年   53篇
  1984年   42篇
  1983年   25篇
  1982年   16篇
  1981年   14篇
  1979年   24篇
  1978年   12篇
  1976年   9篇
  1974年   9篇
  1972年   10篇
  1971年   12篇
  1968年   9篇
排序方式: 共有5875条查询结果,搜索用时 0 毫秒
91.
ObjectiveTo develop and evaluate a risk score to predict people at high risk of developing type 2 diabetes in Pakistan.MethodologyCross sectional data regarding primary prevention of diabetes in Pakistan. Diabetes risk score was developed by using simple parameters namely age, waist circumference, and family history of diabetes. Odds ratios of the model were used to assign a score value for each variable and the diabetes risk score was calculated as the sum of those scores.ResultsWe externally validated the score using two data from 1264 subjects and 856 subjects aged 25 years and above from two separate studies respectively. Validating this score using the first data from the second screening study gave an area under the receive operator characteristics curve [AROC] of 0.758. A cut point of 4 had a sensitivity of 47.0% and specificity of 88% and in the second data AROC is 0.7 with 44% sensitivity and 89% specificity.ConclusionsA simple diabetes risk score, based on a set of variables can be used for the identification of high risk individuals for early intervention to delay or prevent type 2 diabetes in Pakistani population.  相似文献   
92.
93.
94.
95.
96.
Prostate cancer (PCa) and benign prostatic hyperplasia (BPH) are androgen-dependent diseases commonly treated by inhibiting androgen action. However, androgen ablation or castration fail to target androgen-independent cells implicated in disease etiology and recurrence. Mechanistically different to castration, this study shows beneficial proapoptotic actions of estrogen receptor–β (ERβ) in BPH and PCa. ERβ agonist induces apoptosis in prostatic stromal, luminal and castrate-resistant basal epithelial cells of estrogen-deficient aromatase knock-out mice. This occurs via extrinsic (caspase-8) pathways, without reducing serum hormones, and perturbs the regenerative capacity of the epithelium. TNFα knock-out mice fail to respond to ERβ agonist, demonstrating the requirement for TNFα signaling. In human tissues, ERβ agonist induces apoptosis in stroma and epithelium of xenografted BPH specimens, including in the CD133+ enriched putative stem/progenitor cells isolated from BPH-1 cells in vitro. In PCa, ERβ causes apoptosis in Gleason Grade 7 xenografted tissues and androgen-independent cells lines (PC3 and DU145) via caspase-8. These data provide evidence of the beneficial effects of ERβ agonist on epithelium and stroma of BPH, as well as androgen-independent tumor cells implicated in recurrent disease. Our data are indicative of the therapeutic potential of ERβ agonist for treatment of PCa and/or BPH with or without androgen withdrawal.  相似文献   
97.
98.
The human immunodeficiency virus type 1 (HIV-1) rev exons 1 and 2 sequences were analyzed from six mother-infant pairs following perinatal transmission. The rev open reading frame was maintained with a frequency of 93.96% in six mother-infant pairs' sequences. There was a low degree of viral heterogeneity and estimates of genetic diversity in mother-infant pairs' rev sequences. However, the distances of rev sequences between epidemiologically unlinked individuals were greater than in epidemiologically linked mother-infant pairs. Furthermore, phylogenetic parameters revealed that the epidemiologically linked mother-infant pairs were closer evolutionarily to each other as compared with epidemiologically unlinked mother-infant pairs. Both mothers and infants were under positive selection pressure as determined by the ratios of nonsynonymous to synonymous substitutions. The functional domains required for Rev activity, including nuclear export of RNA, RNA binding domain, and nuclear import signals, were conserved in all mother-infant pairs' sequences. The conservation of functional domains of rev and a low degree of heterogeneity following vertical transmission are consistent with an indispensable role of rev in the HIV-1 life cycle.  相似文献   
99.
OBJECTIVE: To study the frequency of neutropenic febrile patients who present in shock, to evaluate the influence of this presenting feature on response to antibiotic therapy, morbidity, and mortality and to identify discriminating demographic features and clinical characteristics of these individuals. METHODS: Prospectively collected data on all episodes of fever and neutropenia observed in cancer patients who were hospitalized for parenteral antibiotic therapy. RESULTS: Five hundred and seventy-six patients were evaluated; 22 (3.8%) presented in shock. This group of individuals was compared with the remainder. Patients presenting in shock were more likely to be older (P< 0.01) and have progressive unresponsive cancer (P< 0.01). They were also more likely to present with septic appearance (P< 0.01), dehydration (P< 0.01), diarrhoea (P< 0.01), altered mental status (P< 0.01) clinical bleeding (P= 0.02) and dyspnoea (P< 0.01). They more often had anaemia (P< 0.01), thrombocytopenia (P= 0.02) and abnormal liver function tests (P< 0.01). Eight of the 22 patients presenting in shock had documented bacteraemia. Non-bacteraemic microbiological infections were observed in three patients. Five patients had clinical evidence of infection and another five were severely dehydrated and volume depleted. One patient had cardiogenic shock. Three patients were managed with monotherapy, 19 received combination antibiotics as initial empirical therapy. Overall outcome of these patients was extremely poor, particularly those with infectious aetiology. Eighteen (82%) patients expired. CONCLUSION: Neutropenic febrile patients who present in shock have extremely poor outcomes irrespective of type of initial antibiotic therapy. Intense efforts are required to improve their outcome.  相似文献   
100.
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