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   1697767篇
  免费   123798篇
  国内免费   3788篇
耳鼻咽喉   21759篇
儿科学   55736篇
妇产科学   46282篇
基础医学   241515篇
口腔科学   48839篇
临床医学   151520篇
内科学   334008篇
皮肤病学   38687篇
神经病学   131280篇
特种医学   63954篇
外国民族医学   242篇
外科学   257598篇
综合类   38956篇
现状与发展   4篇
一般理论   533篇
预防医学   124358篇
眼科学   40225篇
药学   123742篇
  7篇
中国医学   4477篇
肿瘤学   101631篇
  2021年   12849篇
  2019年   13573篇
  2018年   20023篇
  2017年   15250篇
  2016年   16648篇
  2015年   18994篇
  2014年   26272篇
  2013年   38041篇
  2012年   52874篇
  2011年   55560篇
  2010年   32849篇
  2009年   30754篇
  2008年   51632篇
  2007年   54911篇
  2006年   55361篇
  2005年   52666篇
  2004年   50866篇
  2003年   48271篇
  2002年   46454篇
  2001年   91845篇
  2000年   93697篇
  1999年   77054篇
  1998年   19757篇
  1997年   17289篇
  1996年   17405篇
  1995年   16757篇
  1994年   15310篇
  1993年   14085篇
  1992年   57424篇
  1991年   55312篇
  1990年   53015篇
  1989年   50789篇
  1988年   46169篇
  1987年   44980篇
  1986年   42265篇
  1985年   40024篇
  1984年   29375篇
  1983年   24931篇
  1982年   13907篇
  1979年   25553篇
  1978年   17587篇
  1977年   14911篇
  1976年   13883篇
  1975年   14575篇
  1974年   17635篇
  1973年   16955篇
  1972年   15680篇
  1971年   14459篇
  1970年   13436篇
  1969年   12520篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
65.
Although surgical lung resection could improve prognosis in some patients with multidrug-resistant tuberculosis (MDR-TB), there are no reports on the optimal candidates for this surgery. The aim of the present study was to elucidate the prognostic factors for surgery in patients with MDR-TB. Patients who underwent lung resection for the treatment of MDR-TB between March 1993 and December 2004 were included in the present study. Treatment failure was defined as greater than or equal to two of the five cultures recorded in the final 12 months of treatment being positive, any one of the final three cultures being positive, or the patient having died during treatment. The variables that affected treatment outcomes were identified through univariate and multivariate logistic regression analysis. In total, 79 patients with MDR-TB were included in the present study. The treatment outcomes of 22 (27.8%) patients were classified as failure. A body mass index <18.5 kg x m(-2), primary resistance, resistance to ofloxacin and the presence of a cavitary lesion beyond the range of the surgical resection were associated with treatment failure. Low body mass index, primary resistance, resistance to ofloxacin and cavitary lesions beyond the range of resection are possible poor prognostic factors for surgical lung resection in multidrug-resistant tuberculosis patients.  相似文献   
66.
67.
68.
We previously reported poorer survival among non-Hispanic blacks and Hispanics with idiopathic pulmonary fibrosis (IPF) compared to non-Hispanic whites at our center. In the current study, we hypothesized that these disparities would exist in a nationwide cohort of wait-listed patients with IPF. We performed a retrospective cohort study of 2635 patients with IPF listed for lung transplantation between 1995 and 2003 at 94 transplant centers in the United States. The age-adjusted mortality rate was higher among non-Hispanic blacks [hazard ratio (HR) = 1.24, 95% confidence interval (CI) 1.06-1.45, p = 0.009] and Hispanics (HR = 1.29, 95% CI 1.06-1.56, p = 0.01) compared to non-Hispanic whites. These findings persisted after adjustment for transplantation, medical comorbidities and socioeconomic status. Worse lung function at the time of listing appeared to explain some of these differences (HR for non-Hispanic blacks after adjustment for forced vital capacity percent predicted = 1.16, 95% CI 0.98-1.36, p = 0.09; HR for Hispanics = 1.21, 95% CI 0.99-1.48, p = 0.056). In summary, black and Hispanic patients with IPF have worse survival than whites after listing for lung transplant.  相似文献   
69.
We describe the simple adaptation of a standard fluorescent microscope for illumination using a 'Royal Blue' Luxeon light emitting diode (LED) and demonstrate that this form of illumination is suitable for the detection of auramine O stained Mycobacterium spp. The low cost, low power consumption, safety and reliability of LEDs makes them attractive alternatives to mercury vapour lamps.  相似文献   
70.
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