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   36191篇
  免费   2030篇
  国内免费   108篇
耳鼻咽喉   439篇
儿科学   2153篇
妇产科学   704篇
基础医学   4622篇
口腔科学   819篇
临床医学   2525篇
内科学   7371篇
皮肤病学   842篇
神经病学   1901篇
特种医学   880篇
外科学   4990篇
综合类   1439篇
一般理论   15篇
预防医学   2112篇
眼科学   1512篇
药学   3502篇
中国医学   274篇
肿瘤学   2229篇
  2023年   211篇
  2022年   612篇
  2021年   1181篇
  2020年   636篇
  2019年   860篇
  2018年   1050篇
  2017年   722篇
  2016年   956篇
  2015年   999篇
  2014年   1352篇
  2013年   1752篇
  2012年   2414篇
  2011年   2432篇
  2010年   1392篇
  2009年   1252篇
  2008年   1784篇
  2007年   1749篇
  2006年   1775篇
  2005年   1391篇
  2004年   1397篇
  2003年   1186篇
  2002年   1009篇
  2001年   830篇
  2000年   873篇
  1999年   742篇
  1998年   340篇
  1997年   237篇
  1996年   250篇
  1995年   233篇
  1994年   207篇
  1993年   160篇
  1992年   503篇
  1991年   405篇
  1990年   437篇
  1989年   407篇
  1988年   371篇
  1987年   372篇
  1986年   362篇
  1985年   336篇
  1984年   271篇
  1983年   227篇
  1982年   145篇
  1979年   233篇
  1978年   151篇
  1977年   184篇
  1975年   175篇
  1974年   182篇
  1973年   182篇
  1972年   174篇
  1971年   161篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Search is under way to develop reliable tests for the prediction of stone risk. Several indices and ratios on the basis of urinary excretions have been suggested. In the present study the applicability of some risk indices and ratios in slum dwellers of Dharavi area of Bombay was examined. No significant difference was observed in IAP (ionic activity product) and CORI (calcium oxalate risk index) between stone formers (SF) and normal subjects (NS). We have suggested two more adjuncts, PIR (promoter/inhibitor ratio) and COQ (calcium oxalate quotient), and found them to be quite useful in the detection of risk. Pre-existence of risk factor(s) in the majority of the normal population suggests that triggering of stone formation should be a transient phenomenon in this population. No consistent pattern of relationship between various urinary parameters was observed.  相似文献   
72.
73.
74.
A vast majority of the transplant recipients are cytomegalovirus (CMV)-seropositive (R+). We sought to assess variables predictive of CMV infection, specifically in R+ liver transplant recipients. Study patients comprised 182 consecutive liver transplant recipients who survived at least 14 days after transplantation. Surveillance testing was used to detect CMV infection. Pre-emptive therapy was employed for the prevention of CMV disease, however, no antiviral prophylaxis was used for CMV infection. CMV infection developed in 32.5% (38 of 117) of R+ patients, 84.6% (33 of 39) of R-/D+, and 3.8% (1 of 26) of R-/D- patients. In R+ patients, Hispanic race (21.6% vs. 7.8%, P = 0.06), donor CMV seropositivity (73.7% vs. 45.6%, P = 0.005), and hepatocellular carcinoma (23.7% vs. 6.3%, P = 0.05) correlated with a higher risk of CMV infection. In a multivariate model, Hispanic race (OR: 3.5, 95% CI: 1.03-11.6, P = 0.045), donor CMV serostatus (OR: 4.0, 95% CI: 1.6-10.2, P = 0.003) and hepatocellular carcinoma (OR: 5.8, 95% CI: 1.6-20.5, P = 0.006) were all significant independent predictors of CMV infection. The aforementioned variables did not portend a higher risk of CMV infection in R-/D+ patients; donor CMV seropositivity overwhelmed all other risk factors in R- patients (P < 0.00001). In conclusion, CMV-seropositive liver transplant recipients at risk for CMV infection can be identified based on readily assessable variables. Preventive strategies may be selectively targeted toward these patients.  相似文献   
75.
76.
Background: Tibialis posterior is a frequent cause of an acquired flatfoot deformity and the prevalence is not known. If tibialis posterior dysfunction was found to occur frequently, a greater awareness may result leading to earlier patient diagnosis, referral and treatment.Objectives: To validate a screening questionnaire for tibialis posterior dysfunction, and to investigate the prevalence of tibialis posterior dysfunction in a high-risk patient population.Methods: The screening questionnaire was given prospectively to 65 patients (44 females, 21 males; mean age 79.6 years) attending an unrelated care of the elderly appointment. A foot and ankle surgery fellow separately examined all feet for tibialis posterior dysfunction.Results: The survey was 100% sensitive and 98.3 % specific at detecting tibialis posterior dysfunction. Six of the 65 patients (5 females, 1 male) had tibialis posterior dysfunction, and two had bilateral involvement. All six of the patients had longstanding symptoms, all had consulted their doctor and three had seen an orthopaedic surgeon; only one of the six patients had been correctly diagnosed.Conclusions: This study suggests that tibialis posterior dysfunction occurs frequently, but is seldom diagnosed in elderly women. Further epidemiologic studies are needed to determine the true prevalence.  相似文献   
77.
78.
79.
80.
Thyroid function tests were performed on 16 clinically euthyroid patients with end-stage renal failure undergoing regular haemodialysis or continuous ambulatory peritoneal dialysis and compared with 8 healthy subjects. The patient groups were carefully matched, especially regarding relative duration of dialysis (mean of 24 months). Total serum thyroxine, total triiodothyronine, free thyroxine, free triiodothyronine and reverse triiodothyronine were significantly lower in both patient groups than control. The thyrothrophin response to the standard thyrotrophin-releasing hormone test was delayed and blunted. Using a novel concentration technique we measured loss of T4 in peritoneal dialysate effluent and found it to be approximately 10% of daily thyroidal T4 release.  相似文献   
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