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   32721篇
  免费   2240篇
  国内免费   110篇
耳鼻咽喉   258篇
儿科学   1324篇
妇产科学   975篇
基础医学   4434篇
口腔科学   405篇
临床医学   4212篇
内科学   6283篇
皮肤病学   630篇
神经病学   3486篇
特种医学   730篇
外科学   3156篇
综合类   341篇
一般理论   32篇
预防医学   3849篇
眼科学   558篇
药学   1910篇
中国医学   56篇
肿瘤学   2432篇
  2024年   39篇
  2023年   254篇
  2022年   464篇
  2021年   921篇
  2020年   578篇
  2019年   953篇
  2018年   1024篇
  2017年   717篇
  2016年   827篇
  2015年   862篇
  2014年   1216篇
  2013年   1790篇
  2012年   2653篇
  2011年   2709篇
  2010年   1505篇
  2009年   1245篇
  2008年   2172篇
  2007年   2342篇
  2006年   2266篇
  2005年   2142篇
  2004年   1907篇
  2003年   1763篇
  2002年   1694篇
  2001年   228篇
  2000年   172篇
  1999年   220篇
  1998年   319篇
  1997年   284篇
  1996年   216篇
  1995年   188篇
  1994年   152篇
  1993年   186篇
  1992年   109篇
  1991年   91篇
  1990年   68篇
  1989年   65篇
  1988年   78篇
  1987年   40篇
  1986年   45篇
  1985年   40篇
  1984年   54篇
  1983年   54篇
  1982年   54篇
  1981年   45篇
  1980年   51篇
  1979年   33篇
  1978年   36篇
  1977年   24篇
  1974年   18篇
  1973年   17篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Besides distal symmetrical sensory polyneuropathy (DSSP), middle-aged diabetic patients may present with focal or multifocal neuropathies, including proximal neuropathy of the lower limbs, the pathophysiological features of which are uncertain. We studied 10 non–insulin-dependent diabetic patients, 45 to 72 years of age, who developed a painful proximal neuropathy of the lower limbs for which other causes of neuropathy were carefully excluded. The proximal neuropathy was asymmetrical in all patients, sensory in 4, motor and sensory in the others. Signs of DSSP were present in all. A sample of the intermediate cutaneous nerve of the thigh, a sensory branch of the femoral nerve, was taken by biopsy and examined by light and electron microscopy. Examination of the nerve specimens revealed ischemic nerve lesions in 3 patients. Nerve ischemia was associated with vasculitis and inflammatory infiltration in 2 of them. In the other patients the lesions of the cutaneous nerve of the thigh included a varying incidence of axonal and demyelinative lesions similar to those observed in DSSP, with mild inflammatory infiltration in 4 of them. The density of myelinated and of unmyelinated was variably decreased. This study shows that axonal and demyelinative lesions similar to those found in diabetic DSSP are present in proximal nerves in mild forms of proximal diabetic neuropathy; while nerve ischemia, inflammatory infiltration, and vasculitis are encountered in the most severe forms of proximal diabetic neuropathy.  相似文献   
62.
BACKGROUND: Many studies have shown differences in cardiac care by racial/ethnic groups without accounting for institutional factors at the location of care. OBJECTIVE: Exploratory analysis of the effect of hospital funding status (public vs private) on emergency department (ED) triage decision making for patients with symptoms suggestive of acute coronary syndromes (ACSs) and on the likelihood of ED discharge for patients with confirmed ACS. STUDY DESIGN AND SETTING: Secondary analysis of data from a randomized controlled trial of 10,659 ED patients with possible ACS in five urban academic public and five private hospitals. The main outcome measures were the sensitivity and specificity of hospital admission for the presence of ACS at public and private hospitals and the adjusted odds of a patient with ACS not being hospitalized at public versus private hospitals. RESULTS: Of 10,659 ED patients, 1,856 had confirmed ACS. For patients with suspected ACS, triage decisions at private hospitals were considerably more sensitive (99 vs 96%; p<.001) but less specific (30 vs 48%; p<.001) than at public hospitals. The difference between hospital types persisted after adjustment for multiple patient-level and hospital-level characteristics. CONCLUSION: Significant differences in triage for patients with suspected ACS exist between public and private hospital EDs, even after adjustment for multiple patient demographic, clinical, and institutional factors. Further studies are needed to clarify the causes of the differences.  相似文献   
63.
64.
65.
66.
67.
Despite continued improvement in incidence of acute immune injury and short-term graft survival, late allograft dysfunction remains a significant problem in the renal transplant population. Recent reports suggest that rates of renal function decline are quite varied in the overall recipient population, and that individual rates for many recipients may not change substantially over time. Moreover, analyses also reveal distinct predictive factors for both early and late functional decline. Long-term outcome studies for renal transplantation, however, might be significantly limited by incomplete data sets for assessing clinical endpoints. In view of the heterogeneous factors that may cause progressive allograft injury, more routine biopsy sampling would allow a more complete characterization of induced injuries. Elucidating mechanisms of renal fibrosis in response to injury, in experimental systems and humans, is also an important goal in better understanding chronic allograft damage. Regulation of cell senescence genes and epithelial to mesenchymal transition, studied in other models of renal fibrosis, are likely relevant to studies of renal allograft dysfunction. Recent technical advances in analyzing biological samples may play a pivotal role in identifying and validating surrogate markers of allograft function for future interventional trials in transplantation.  相似文献   
68.
69.
ONE OF THE RISK FACTORS FOR HUMAN PAPILLOMAVIRUS (HPV) INFECTION and subsequent lower genital tract neoplasias and cancers is impaired cell-mediated immunity. HIV-positive women with severe immunosuppression are 5 times more likely than HIV-negative women to have lower genital tract neoplasias. A corresponding increase in the risk of invasive vulvar and anal cancers, but not of cervical cancer, has also been observed among HIV-positive women. Treatment failure and recurrence of neoplasia occur much more frequently among HIV-positive than among HIV-negative women. In this review, we discuss recent advances in the understanding of the relation between HIV and HPV coinfection and the development of lower genital tract neoplasias and cancers in women. In addition, we present strategies for monitoring and treating noninvasive and invasive neoplasias of the lower genital tract in HIV-positive women.  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