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   15981篇
  免费   1045篇
  国内免费   54篇
耳鼻咽喉   341篇
儿科学   518篇
妇产科学   436篇
基础医学   2244篇
口腔科学   329篇
临床医学   1401篇
内科学   2690篇
皮肤病学   611篇
神经病学   1516篇
特种医学   951篇
外科学   2746篇
综合类   171篇
一般理论   19篇
预防医学   888篇
眼科学   431篇
药学   772篇
中国医学   6篇
肿瘤学   1010篇
  2021年   189篇
  2020年   107篇
  2019年   190篇
  2018年   278篇
  2017年   224篇
  2016年   287篇
  2015年   302篇
  2014年   446篇
  2013年   564篇
  2012年   681篇
  2011年   715篇
  2010年   498篇
  2009年   484篇
  2008年   646篇
  2007年   748篇
  2006年   691篇
  2005年   672篇
  2004年   608篇
  2003年   572篇
  2002年   595篇
  2001年   520篇
  2000年   519篇
  1999年   483篇
  1998年   294篇
  1997年   275篇
  1996年   259篇
  1995年   208篇
  1994年   211篇
  1993年   153篇
  1992年   343篇
  1991年   341篇
  1990年   283篇
  1989年   318篇
  1988年   267篇
  1987年   251篇
  1986年   278篇
  1985年   249篇
  1984年   179篇
  1983年   144篇
  1982年   105篇
  1981年   106篇
  1979年   130篇
  1978年   104篇
  1977年   92篇
  1976年   94篇
  1975年   93篇
  1974年   101篇
  1973年   109篇
  1971年   95篇
  1970年   84篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
6.
We report the case of a patient with a 13-year history of pemphigus vulgaris (PV) treated with immunosuppressive agents, prednisone and mycophenolate mofetil who had developed lesions of Kaposi's sarcoma (KS) on a sole plaque of PV that had been previously treated with intralesional injections of steroids. The lesions were surgically removed and polymerase chain reaction (PCR) demonstrated human herpesvirus-8 (HHV-8) DNA. There were neither recurrences nor later dissemination of KS following gradual decrease of the immunosuppressive therapy. We suggest that the treatment with intralesional steroids may have influenced the local reactivation of a latent infection of the virus, determining the appearance of this localized KS.  相似文献   
7.
Objective: Descending and ascending aortomyoplasty are two surgical procedures intended to induce hemodynamic benefits similar to those of the intra-aortic-balloon-pump (IABP). To date, there have been no studies comparing the two surgical techniques. The objective of this study was to compare coronary blood flow augmentation and afterload reduction as produced by descending and ascending aortomyoplasty counterpulsation Methods: Twenty-two mongrel dogs (18–35 kg) underwent IABP application (n=7), descending (n=8), or ascending (n=7) aortomyoplasty. Left anterior descending (LAD) coronary artery blood flow was measured using a Transonic Doppler flow probe. Left ventricular pressure as well as aortic pressures proximal and distal to either the aortomyoplasty site or the IABP position were monitored continuously. Results: Descending aortomyoplasty induced higher elevation in the LAD blood flow during assisted beats (27% from 10.8±4 to 13.8±6 ml/min, P<0.001) than that induced by either ascending aortomyoplasty (19% from 11.7±5 to 14±5 ml/min, P<0.001) or IABP counterpulsation (18% from 8.6±3 to 10.2±4 ml/min, P<0.001). Conversely, while ascending aortomyoplasty reduced the left ventricular end-diastolic pressure by 16% (from 60±18 to 50±22 mmHg, P<0.001), similar to the 16% after load reduction achieved by the IABP counterpulsation, descending aortomyoplasty failed to induce afterload reduction. Conclusions: Descending aortomyoplasty produces higher coronary blood flow augmentation than either ascending aortomyoplasty or IABP. However, afterload reduction comparable to that achieved by IABP was observed only with ascending aortomyoplasty and not with descending aortomyoplasty.  相似文献   
8.
We report on 9 patients with pilomatricomas that showed unusual histopathologic features. Our patients were mainly elderly individuals (age range 42 to 88 years; mean age 70.1 years) who presented solitary cutaneous nodules situated on the head and neck (7 neoplasms), upper arm (1 neoplasm), and back (1 neoplasm). All the lesions were treated by simple excision. Follow-up data available in 7 of the 9 patients (mean follow-up, 17 months) revealed local recurrences in 1 patient whose lesion recurred 3 times. No lymph node involvement or distant metastases were recorded in any of our cases. Histopathologically, most neoplasms were characterized by a relatively large lesion in the clermis that in some cases showed extension to the subcutis. Each lesion was predominantly composed of a lobular proliferation of basaloid cells in association with adjacent focal areas containing eosinophilic, cornified material with shadow cells. In some cases, relatively large areas of shadow cells were present, whereas, in others only small foci of shadows cells were observed. Cytomorphologically, the basaloid cells showed features of matrical and supramatrical cells of a normal hair follicle and exhibited variable nuclear atypia and mitotic figures. The overall architectural pattern of the neoplasms was different from that of large fully developed stereotypical pilomatricomas that maintain a cystic character with basaloid cells predominantly aligned at the periphery. Based on the histopathologic findings, namely the presence of a large, lobular proliferation of basaloid cells in association with small to large foci of shadow cells, we interpreted these neoplasms to be a distinctive proliferative variant of pilomatricoma and propose the designation "proliferating pilomatricoma." Proliferating pilomatricomas should be differentiated from the recently described matricoma, basal-cell carcinoma with matrical differentiation, and matrical carcinoma (pilomatrical carcinoma).  相似文献   
9.
10.
The relationship between stroke and physical disability was examined in a cohort of adult, Framingham, Massachusetts, residents who, between 1948 and 1951, were assembled for a longitudinal examination of cardiovascular disease. Multivariate analyses examined the amount of residual disability attributable to stroke among 2540 community-dwelling survivors, 27 years after their initial examination, after controlling for age, cardiovascular risk factors, other cardiovascular diseases, and eight general health conditions related to physical disability. Among men living in the community, a history of stroke explained 12% of the variance in physical disability. Suffering a stroke, however, was not as strongly related to physical disability among women living in the community, accounting for only 3% of the variance. Results suggest that although older men and women die from the same major causes, they may not be disabled by the same conditions.  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