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   945012篇
  免费   64749篇
  国内免费   2679篇
耳鼻咽喉   12969篇
儿科学   29795篇
妇产科学   27296篇
基础医学   132407篇
口腔科学   27260篇
临床医学   78284篇
内科学   193703篇
皮肤病学   19898篇
神经病学   75507篇
特种医学   37792篇
外国民族医学   336篇
外科学   148078篇
综合类   19401篇
一般理论   258篇
预防医学   68235篇
眼科学   20677篇
药学   66715篇
中国医学   2057篇
肿瘤学   51772篇
  2019年   7674篇
  2018年   10614篇
  2017年   8339篇
  2016年   8976篇
  2015年   10203篇
  2014年   14283篇
  2013年   21500篇
  2012年   29194篇
  2011年   31009篇
  2010年   18608篇
  2009年   17521篇
  2008年   29011篇
  2007年   30520篇
  2006年   30469篇
  2005年   29717篇
  2004年   28414篇
  2003年   27387篇
  2002年   26770篇
  2001年   41884篇
  2000年   43090篇
  1999年   36760篇
  1998年   10278篇
  1997年   9406篇
  1996年   9342篇
  1995年   8650篇
  1994年   8236篇
  1993年   7738篇
  1992年   28449篇
  1991年   27190篇
  1990年   26613篇
  1989年   25565篇
  1988年   23725篇
  1987年   23331篇
  1986年   22388篇
  1985年   21282篇
  1984年   15931篇
  1983年   13584篇
  1982年   8147篇
  1979年   14665篇
  1978年   10283篇
  1977年   8681篇
  1976年   8190篇
  1975年   9006篇
  1974年   10759篇
  1973年   10238篇
  1972年   9690篇
  1971年   8958篇
  1970年   8637篇
  1969年   8072篇
  1968年   7713篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
During a 3-year period Branhamella catarrhalis was isolated in significant numbers from 239 (1.3%) of 19,488 specimens of sputum sent for routine microbiological examination at a 700-bed general hospital. The majority of patients (83%) were over 60 years of age and 65% were male. There was a distinct seasonal variation in isolations with a peak incidence during the winter and early spring, a pattern not found with other pathogens. Susceptibility to amoxycillin decreased by approximately 50% over the 3 years, corresponding to an increased incidence of beta-lactamase-producing strains. There were minimal changes in susceptibility to other antimicrobial agents. Underlying pulmonary disease was the major factor predisposing to B. catarrhalis infection, and 71% of patients were smokers or ex-smokers.  相似文献   
993.
ABSTRACT— One hundred and fifty-four patients with histologically verified nonalcoholic chronic liver disease were randomized to azathioprine or prednisone treatment. After a median of 91 months observation time, the cause of death was assessed retrospectively. Autopsy was performed in 82% of 71 deaths. In the azathioprine group 33% (13/39) died from malignant neoplasia, and in the prednisone group (13%) (4/32) (p = 0.08). Considering a possible fatal outcome as a consequence of treatment, this finding urges caution in the long-term application of azathioprine at the usual dose level.  相似文献   
994.
To determine the relationship between severity of illness and mortality, therapeutic intervention score (TISS) and acute physiology score (APS) were determined on admission to the Surgical Intensive Care Unit (SICU). Patients were divided into survivors and nonsurvivors and differences were compared by chi-square analysis. The 1524 patients admitted to the SICU during a 12-month period had a mean TISS of 3.03 and a mean APS of 13. The average length of stay (LOS) was 3.75 days. Of the 1524 patients, 97 (6.4%) died. The number of nonsurvivors increased with higher TISS and APS scores (P less than 0.001). There were no deaths in the TISS Category 1 patients or in the APS 0-5 group. Mortality rates dramatically increased with APS greater than 20 (P less than 0.001). There were 1286 patients with APS less than 20, and 24 (2%) of these patients died, whereas 73 (31%) of 238 patients with APS greater than 20 died. Nonsurvivors had a mean TISS of 3.6, mean APS of 27, and LOS of 4.88 days, all of which totals were higher than the survivors' totals. In this study population, risk of death was one in three if the APS was greater than 20. These data indicate that TISS and APS scores are effective means of assessing mortality risk in SICU patients.  相似文献   
995.
996.
997.
998.
The physically disabled physician   总被引:1,自引:0,他引:1  
S F Wainapel 《JAMA》1987,257(21):2935-2938
This article reviews the available literature on physically disabled physicians and discusses the attitudinal, environmental, and political barriers they may encounter. Information on 215 physicians and 92 medical students with a wide range of disabilities was analyzed. Currently available personal and technological resources are outlined and special issues pertaining to medical education are highlighted. Greater awareness and acceptance by medical peers are essential for professional success.  相似文献   
999.
Sixteen patients underwent surgical treatment for severe renovascular hypertension with rapidly progressive renal failure. These patients were assessed preoperatively with the measurement of serum creatinine and blood-urea levels (means 271 +/- 204 mumol/l and 15.6 +/- 10.3 mmol/l respectively), and renal clearances. 5 patients underwent aorto-renal bypass (bilateral in one case) and 11 patients were treated by autotransplantation of the kidney. Operative mortality was 6.2%. Early results were assessed at 1 and 6 months postoperatively. Renal function was normal in 8 patients, improved in 5 (p less than 0.05), unchanged in 1 and worse in 1 by aorto-renal bypass thrombosis. At long-term with a minimum follow-up of 12 months (mean 31 +/- 12 months), the initial improvement in renal function remained steady in 12 patients whilst 1 patient has gone on to hemodialysis. At middle and long-term, 81% of the patients were normotensive without medication or had improved blood pressure (p less than 0.001). These good results confirm the reversibility of renal ischemic lesions and support an aggressive attitude towards the use of revascularization in the surgical treatment of such patients with renovascular hypertension and renal failure.  相似文献   
1000.
Monoclonal antibodies against human and bovine 2′:3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) were generated by fusing FOX-NY myeloma cells with spleen cells from RBF/Dn mice previously immunized with the purified brain antigens. The enzyme isolated from bovine brain was quite basic, with an isoelectric point of 9.71 and both the bovine and human enzymes consisted of a closely spaced doublet at approximately 44 and 46 kDa on SDS-PAGE. Six monoclonals were identified as strongly recognizing the enzyme on both ELISA plates and on immunoblots of whole brain protein. Four monoclonals very weakly cross-reacted with guinea pig myelin basic protein. In contrast with two previous reports, some of our monoclonal antibodies did immunostain 2 or 3 protein bands in peripheral nerve, two bands closely corresponding to those immunostained in central nervous system (CNS) myelin, the Wolfgram protein fraction and in acetone powders of whole brain. Each of the 6 monoclonals reacting strongly on immunoblots recognized the enzyme in from 2 to 5 of the species examined (human, bovine, rat, mouse and rabbit). In addition, all 6 monoclonals that immunostained the enzyme in whole brain, myelin and Wolfgram protein immunoblots recognized both CNP1 (44 kDa) and CNP2 (46 kDa). The two closely spaced protein bands observed on SDS-PAGE and previously stained on immunoblots of CNS CNPase using polyvalent rabbit anti-bovine CNPase antisera, and now different monoclonal antibodies, appear to be immunologically related and to contain highly conserved sequences.  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