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   1348808篇
  免费   97223篇
  国内免费   2691篇
耳鼻咽喉   19063篇
儿科学   44362篇
妇产科学   39531篇
基础医学   196770篇
口腔科学   37096篇
临床医学   114210篇
内科学   266973篇
皮肤病学   28010篇
神经病学   106023篇
特种医学   52838篇
外国民族医学   386篇
外科学   207434篇
综合类   28049篇
现状与发展   1篇
一般理论   341篇
预防医学   96936篇
眼科学   30254篇
药学   103549篇
  4篇
中国医学   2963篇
肿瘤学   73929篇
  2018年   13425篇
  2016年   11392篇
  2015年   13189篇
  2014年   18077篇
  2013年   27356篇
  2012年   37497篇
  2011年   40066篇
  2010年   23949篇
  2009年   22390篇
  2008年   38525篇
  2007年   41665篇
  2006年   42029篇
  2005年   41181篇
  2004年   40025篇
  2003年   38878篇
  2002年   38452篇
  2001年   60516篇
  2000年   61856篇
  1999年   52499篇
  1998年   15057篇
  1997年   13488篇
  1996年   13677篇
  1995年   12877篇
  1994年   12280篇
  1993年   11332篇
  1992年   42083篇
  1991年   41437篇
  1990年   40804篇
  1989年   39613篇
  1988年   36902篇
  1987年   36077篇
  1986年   34448篇
  1985年   32793篇
  1984年   24426篇
  1983年   21259篇
  1982年   12686篇
  1981年   11203篇
  1979年   23027篇
  1978年   16139篇
  1977年   13988篇
  1976年   13189篇
  1975年   14495篇
  1974年   17038篇
  1973年   16416篇
  1972年   15622篇
  1971年   14513篇
  1970年   13470篇
  1969年   12976篇
  1968年   12217篇
  1967年   10707篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Eighty-eight patients with blunt renal trauma were examined sonographically. Rupture of the kidney was diagnosed in 41 patients and contusion of the kidney in 45. The correlation between operative findings, sonography and urography showed positive sonographic findings to be correct in all patients with rupture of the kidney. In 4 patients with normal sonograms, the diagnosis of a contusion was based on the urographic results. Three patients underwent angiography. An intimal lesion was seen in 2 and a tear of the renal artery in 1. The results of our investigation suggest that sonography should be applied in the first place in the evaluation of blunt renal trauma. It is the investigation of choice during follow-up after surgical as well as conservative therapy.  相似文献   
92.
93.
Multiple trauma is often associated with blunt thoracic injuries. Especially lung contusion can result in respiratory insufficiency and therefore a higher mortality rate. In our prospective study comparing 8 multiple trauma patients with and without associated lung contusion, we found that respiratory function was already significantly disturbed (decrease of paO2/FiO2 and increase of AaDO2, a rise in extravascular lung water (EVLW) both early after trauma and also with a second peak following the 4th day. This group (LK) developed significantly more cases of respiratory distress (ARDS). The disturbance of respiratory function seen initially was interpreted as a consequence of the direct mechanical impact, leading to the formation of interstitial fluid and hematoma. The frequent development of ARDS in the LK-group probably results from a pronounced activation of cellular and humoral mechanisms and therefore an enforced injury of the pulmonary capillary bed. A significant increase of pulmonary infections or the development of sepsis was not seen in the LK-group and is probably not responsible for the higher ARDS-rate in this group.  相似文献   
94.
95.
96.
Concanavalin A-induced lymphocyte proliferation was studied in 25 patients with alcoholic hepatitis or compensated alcoholic cirrhosis. Nine alcoholics without evidence of liver disease were also evaluated. A nonlinear correlation equation, which was natural logarithmic, was applied to individual dose-response proliferation curves and permitted comparisons between patient groups and controls. The proliferative response in all patient groups was significantly lower when compared to healthy controls and was independent of the presence or absence of liver disease. This suggests that some changes in immune function observed in alcoholics may be linked to the direct effects of alcohol on the immune system rather than to the associated liver disease.  相似文献   
97.
131 patients with resectable, node-positive breast cancer were treated at the National Institute for Cancer Research of Genoa, Italy with a systemic adjuvant regimen based on 14 cycles of chemotherapy, immunostimulation with levamisole, and--for postmenopausal patients--hormone therapy with tamoxifen. The present evaluation is performed eleven years after the admission of the first patient: so far, 75 patients (57.3%) have relapsed and 52 (39.7%) have died. An analysis of prognostic factors for relapse and death shows that the number of positive axillary lymph nodes and the dimension of the primary tumor are significantly associated with survival and relapse-free survival, while age and menopausal status are not.  相似文献   
98.
99.
从土藿香根中得到两个二萜化合物,藿香酚(2)及异藿香酚(3)。经光谱解析(IR,UV,HRMS及NMR谱),确定它们的结构分别为11,14dihydroxy12methoxy19(4→3)abeoabieta4,(18),8,11,13tetraen7one(2)和11,14dihydroxy12methoxy19(4→3)abeoabieta3,8,11,13tetraen7one(3)藿香酚(2)为一新的化合物,而异藿香酚(3)系首次从天然界分离得到,二者为一对异构体。  相似文献   
100.
Macrophage NRAMP1 and its role in resistance to microbial infections   总被引:12,自引:0,他引:12  
  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