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   3270569篇
  免费   260975篇
  国内免费   6741篇
耳鼻咽喉   46497篇
儿科学   103276篇
妇产科学   89956篇
基础医学   457935篇
口腔科学   93311篇
临床医学   301056篇
内科学   637879篇
皮肤病学   69523篇
神经病学   275024篇
特种医学   128134篇
外国民族医学   1191篇
外科学   489723篇
综合类   79232篇
现状与发展   4篇
一般理论   1381篇
预防医学   267678篇
眼科学   77400篇
药学   239633篇
  6篇
中国医学   6583篇
肿瘤学   172863篇
  2018年   35326篇
  2017年   27078篇
  2016年   30077篇
  2015年   33939篇
  2014年   48809篇
  2013年   74047篇
  2012年   99801篇
  2011年   105534篇
  2010年   62201篇
  2009年   59506篇
  2008年   98998篇
  2007年   105269篇
  2006年   106169篇
  2005年   103348篇
  2004年   99110篇
  2003年   95341篇
  2002年   93243篇
  2001年   151690篇
  2000年   156451篇
  1999年   131830篇
  1998年   38948篇
  1997年   35185篇
  1996年   34859篇
  1995年   33374篇
  1994年   31100篇
  1993年   29108篇
  1992年   104193篇
  1991年   100200篇
  1990年   96509篇
  1989年   92809篇
  1988年   86043篇
  1987年   84672篇
  1986年   79813篇
  1985年   76343篇
  1984年   58310篇
  1983年   49717篇
  1982年   30507篇
  1981年   27133篇
  1979年   53941篇
  1978年   38096篇
  1977年   31969篇
  1976年   30089篇
  1975年   31302篇
  1974年   38490篇
  1973年   36738篇
  1972年   34534篇
  1971年   31710篇
  1970年   29992篇
  1969年   27925篇
  1968年   25850篇
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
991.
992.
993.
In order to determine if serial, noninvasive evaluation of polytetrafluoroethylene (PTFE) vascular access grafts could identify a subgroup of patients at risk for thrombosis, the authors studied flow characteristics, using duplex ultrasonic scanning, in 18 hemodialysis patients with forearm loop grafts. On average, five examinations were performed per patient over the 10-month study period. Seven episodes of thrombosis occurred in six patients. The mean Doppler flow in grafts that subsequently thrombosed was significantly lower than in those that did not (544 +/- 218 ml/min versus 843 +/- 391 ml/min, p less than 0.001). The interval from last examination to thrombosis ranged from 13 to 58 days. At a defined cut-off flow of 450 ml/min, this test yielded a sensitivity of 83% and a specificity of 75% for episodes of thrombosis occurring within 2 to 6 weeks. The authors conclude that episodes of thrombosis in PTFE arm loop grafts are usually preceded by significantly lower Doppler-measured flow than grafts that do not thrombose and that it may be possible, by this means, to identify grafts at risk.  相似文献   
994.
The records of 29 consecutive patients treated by a pure, open, anterior acromioplasty were reviewed retrospectively. Excluded from consideration were patients with the following pathologic diagnoses or histories: (1) previously attempted acromioplasty on the same shoulder; (2) intraoperatively confirmed rotator cuff tear; (3) any surgically treatable biceps tendon or acromioclavicular abnormality; (4) lost to follow-up study. Three different techniques were employed to perform the acromioplasties. The first technique required partial deltoid origin detachment with an osteotome. The second technique spared the deltoid origin, while again using an osteotome to perform the acromioplasty. The third technique also spared the deltoid origin but used a high-speed burr to perform the acromioplasty. Evaluated in terms of patient satisfaction, residual pain, length of convalescence, suboptimal results, and complications, the first technique proved to be the least effective. The second technique produced early, excellent results. The third technique, in which a burr was employed through an intact deltoid origin, was most effective; technically, the method was also relatively simple and reliable.  相似文献   
995.
Several reports in the literature suggest a relationship between lead intoxication and thermoregulatory capacity. To investigate the effects of lead on the control of body temperature, mice of the BALB/c strain were injected intraperitoneally with lead acetate (0 to 100 mg/kg) while colonic temperature was measured 30, 60, and 90 min post-injection at ambient temperatures (Ta) of 20 and 30 degrees C. Lead acetate caused a transient hypothermia, an effect which was augmented at cooler Ta's. In a second experiment, mice were injected with 100 mg/kg lead acetate and placed in a longitudinal temperature gradient to measure their preferred Ta. Lead acetate significantly reduced the preferred Ta during the first 30 min post-injection which augmented the lead-induced hypothermia. In a third experiment it was found that lead acetate-induced lethality was potentiated with increasing Ta. Hence, the hypothermic response to acute lead acetate treatment may be beneficial to survival.  相似文献   
996.
A case of Goldenhar’s Syndrome in a 10 year old girl is reported. The unusual features are the absence of epibulbar dermoid which is one of the major hallmarks of the Syndrome and the presence of an associated Cyanotic Heart disease.  相似文献   
997.
The Alaska mental health program is endowed with a 1-million-acre trust fund. A coalition of groups that make up the mental health constituency of the state united in a lawsuit to establish the trust. The history of this legacy, the struggle to realize its benefits, its current status, and some of its psychopolitical significance are discussed.  相似文献   
998.
999.
1000.
Outcomes were compared between consecutive patients who had received either total lymphoid irradiation (TLI) or immunosuppressant treatment for intractable rheumatoid arthritis (RA). There were 33 TLI and 32 immunosuppressive recipients; all patients had failed standard therapy. Average followup from the start of therapy was 2.7 years for TLI and 5.9 years for immunosuppressive recipients. Final disability levels were the same in both groups; mortality was equal in both groups as well. There were more hospitalizations for infections in the TLI group and the infecting organisms tended to be staphylococcus or gram negative organisms. Apart from infections, there were more adverse effects reported in the immunosuppressive therapy group.  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