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   2375272篇
  免费   194632篇
  国内免费   4209篇
耳鼻咽喉   34264篇
儿科学   72762篇
妇产科学   62953篇
基础医学   334905篇
口腔科学   67524篇
临床医学   215535篇
内科学   468623篇
皮肤病学   47934篇
神经病学   200785篇
特种医学   95964篇
外国民族医学   886篇
外科学   360411篇
综合类   56221篇
现状与发展   1篇
一般理论   977篇
预防医学   190614篇
眼科学   55477篇
药学   177531篇
  4篇
中国医学   4365篇
肿瘤学   126377篇
  2018年   24209篇
  2016年   20577篇
  2015年   23284篇
  2014年   33537篇
  2013年   50836篇
  2012年   68749篇
  2011年   72285篇
  2010年   42473篇
  2009年   40871篇
  2008年   68768篇
  2007年   73113篇
  2006年   74005篇
  2005年   72049篇
  2004年   69347篇
  2003年   67029篇
  2002年   66269篇
  2001年   112453篇
  2000年   116528篇
  1999年   98338篇
  1998年   27861篇
  1997年   25526篇
  1996年   25448篇
  1995年   24612篇
  1994年   23163篇
  1993年   21553篇
  1992年   79390篇
  1991年   76397篇
  1990年   73575篇
  1989年   70842篇
  1988年   65846篇
  1987年   64802篇
  1986年   61337篇
  1985年   58401篇
  1984年   44224篇
  1983年   37657篇
  1982年   22886篇
  1981年   20333篇
  1980年   19034篇
  1979年   41299篇
  1978年   28988篇
  1977年   24346篇
  1976年   22833篇
  1975年   23964篇
  1974年   29640篇
  1973年   28042篇
  1972年   26228篇
  1971年   24152篇
  1970年   22752篇
  1969年   21089篇
  1968年   19135篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
4260 conjunctival specimens of 2850 outpatients with keratoconjunctivitis of presumed infectious etiology were studied. Two thousand six hundred sixty-eight specimens (63%) revealed growth of bacteria, and 80 (2%) growth of fungi. One hundred ninety-nine specimens (5%) were McCoy cell culture or direct stain (monoclonal antibody or Giemsa) positive for Chlamydia trachomatis. two patients had a C. psittaci infection (ELISA techniques). In patients with keratoconjunctivitis of bacterial etiology, overall incidence of McCoy cell culture-proven chlamydial infections was 7%; in the 20 to 30-year age group it was 12.5%. Simultaneous infections of chlamydiae and other bacteria were seen in 34 patients. Since sensitive and specific tests to diagnose chlamydial infections are available, ophthalmologists may be able to prevent these infections by agent-specific antibiotic therapy.  相似文献   
972.
The Brief Symptom Inventory (BSI), a 53-item psychiatric symptom checklist, was administered to 57 alcoholic inpatients on days 2, 10, 18 and 26 of their 28-day stay in an alcoholism rehabilitation unit at a Veterans Administration hospital. The results of the test show a steady decline in the patients' psychiatric symptomatology from week 1 to week 4 with the most dramatic improvement evidenced between weeks 1 and 2.  相似文献   
973.
974.
The in vitro activities of beta-lactam antibiotics against Bacteroides fragilis and B. fragilis group isolates are presented. Clinical isolates from 1986 were compared with strains from 1979 to 1982. Imipenem, ticarcillin-clavulanic acid, and ceftizoxime were the most active agents. Cefotetan was equivalent to cefoxitin against B. fragilis but less active against B. fragilis group isolates. Enhancement of cefotaxime by its desacetyl metabolite was minimal.  相似文献   
975.
976.
977.
Malignant mixed müllerian tumor of the fallopian tube is an extremely rare neoplasm, with less than 30 cases reported. Clinical signs and symptoms are usually nonspecific and include lower abdominal pain, fever, and vaginal bleeding. The age at diagnosis varies from 14 to 76 years, with a mean of 55 years. Prognosis is poor, with only one woman surviving more than five years. Surgery is the treatment of choice, although chemotherapy may be of some benefit.  相似文献   
978.
979.

Background  

A standardised suction technique has been used to sample plasma proteins in dermal interstitial fluid (IF) serially for 5 to 6 days from a suction-induced skin mini-erosion. Increased protein concentrations ascribed to inflammation have been shown from day 1 onward. In this study, we assessed the effect of two different extraction pressures on IF sample composition.  相似文献   
980.
Increased peripheral NK cells in aborting women are considered as a predictor of immunological miscarriages. Here, we investigated the diagnostic value of the NK count at the time of abortion. Peripheral NK cells were counted by flow cytometry in 44 women undergoing therapeutic termination of first trimester missed pregnancy (A = 24) or elective abortion (B = 20). Histology of the extracted material was performed and immunological lesions (villitis, intervillositis, vascular thrombosis, increased fibrinoid necrosis) were recorded. Twenty first trimester pregnant women (C1) and 20 nonpregnant women (C2) served as controls. In 20 women of groups A and B (A1 = 10, B2 = 10) count was repeated after 5 days. At abortion time, the NK percentage and number did not differ between groups A and B (18.18%, 360 versus 15.61%, 374), but there was a statistically significant difference between A and C1 (18.18% versus 13.6%, P < 0.03). When histology negative (11) and positive (8) cases were excluded from groups A and B, respectively, NKs were slightly higher in group A (18.18–19.76%) and significantly lower in B (15.61–13.07%, P < 0.05). At the time of second count, aborters' NKs decreased (A1 = 16.64 versus 13.6 and 10.6 in groups C1 and C2 –P = 0.01, respectively). In group B, NK percentage was equal to that of nonpregnant women (10.94 versus 10.6). At the time of abortions, NKs increase only in cases of immune‐mediated miscarriages. Their – in time – count may contribute to the diagnosis of immmunological abortions.  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