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   2497篇
  免费   162篇
  国内免费   76篇
耳鼻咽喉   5篇
儿科学   182篇
妇产科学   37篇
基础医学   266篇
口腔科学   61篇
临床医学   315篇
内科学   591篇
皮肤病学   99篇
神经病学   102篇
特种医学   398篇
外科学   138篇
综合类   53篇
预防医学   220篇
眼科学   38篇
药学   105篇
  2篇
中国医学   1篇
肿瘤学   122篇
  2023年   10篇
  2022年   11篇
  2021年   15篇
  2020年   20篇
  2019年   27篇
  2018年   39篇
  2017年   33篇
  2016年   38篇
  2015年   46篇
  2014年   56篇
  2013年   77篇
  2012年   62篇
  2011年   77篇
  2010年   117篇
  2009年   103篇
  2008年   75篇
  2007年   113篇
  2006年   65篇
  2005年   77篇
  2004年   49篇
  2003年   35篇
  2002年   44篇
  2001年   53篇
  2000年   39篇
  1999年   36篇
  1998年   132篇
  1997年   165篇
  1996年   141篇
  1995年   112篇
  1994年   118篇
  1993年   101篇
  1992年   41篇
  1991年   51篇
  1990年   49篇
  1989年   61篇
  1988年   54篇
  1987年   52篇
  1986年   58篇
  1985年   51篇
  1984年   34篇
  1983年   21篇
  1982年   29篇
  1981年   35篇
  1980年   27篇
  1979年   4篇
  1978年   9篇
  1977年   19篇
  1976年   26篇
  1975年   14篇
  1968年   3篇
排序方式: 共有2735条查询结果,搜索用时 15 毫秒
31.
Hall  FM; Storella  JM; Silverstone  DZ; Wyshak  G 《Radiology》1988,167(2):353-358
Carcinoma was found in 30% (119 of 400) of biopsy specimens obtained for mammographically suspicious but nonpalpable findings. The authors reviewed the mammograms of these 400 cases without knowledge of the biopsy results and placed each examination into one of four groups based on their suspicion for carcinoma: minimal (n = 82), slight (n = 91), moderate (n = 174), and high (n = 53). In 127 cases, mammograms showed either minimally suspicious calcifications (n = 33) or minimally (n = 49) or slightly (n = 45) suspicious masses. A 4.7% (six of 127) rate of carcinoma was found in these groups; five of the six cancers were in situ. Had follow-up mammography been done rather than biopsy for these 127 less suspicious lesions, it is probable that the delay in diagnosis would not have altered overall prognosis. In the remaining 273 patients, the positive predictive value of mammography for carcinoma would have risen from 30% (119 of 400) to 41% (113 of 273). The authors conclude that in the management of suspicious nonpalpable mammographic findings, the rate of carcinoma for lesions at biopsy can approximate 40%. This is almost double the rate of most published series.  相似文献   
32.
High-dose (HD) cytosine arabinoside (ARA-C) is more effective treatment than conventional-dose ARA-C regimens for patients with relapsed acute nonlymphocytic leukemia (ANLL). We report here that HD ARA-C given during the first remission of ANLL has resulted in long remission durations and a high proportion of patients who survive more than three years free of disease. From August 1979 to September 1983, 36 adult patients with ANLL in first remission received one to three courses of HD ARA-C (3 g/m2 by one-hour infusion every 12 hours for 12 doses on days 1 through 6) alone or with daunorubicin (30 mg/m2 for two or three doses on days 7 through 9). Three patients died of sepsis or hemorrhage during consolidation, and 14 patients have relapsed from five to 48 months after diagnosis. The remaining 19 patients are in continued complete remission (CCR) from 11 to 62 months. Denoting all deaths in remission as relapse, the actuarial probability of CCR is 42% at 62 months, with an apparent plateau in the survival curve. Of the first 22 patients treated, ten remain in CCR from 37 to 62 months with no therapy for at least three years. Due to its heightened anti-leukemic activity, HD ARA-C allows brief but effective consolidation of ANLL in first remission, with long-term disease-free survival comparable to other approaches.  相似文献   
33.
In 22 patients with malignancies, treated with high-dose chemoradiotherapy and autologous bone marrow transplantation (BMT), peripheral blood T cell subsets and functions were studied. In ten cytomegalovirus (CMV)-negative patients, CD4+ and CD8+ T cells (representing T cells of the helper/inducer phenotype and T cells of the suppressor/cytotoxic phenotype, respectively), recovered slowly and simultaneously. In 12 CMV-positive patients, however, CD8+ T cells recovered more rapidly than CD4+ T cells and rose to increased counts. No T cells with an immature phenotype (CD1+, OKT6+) were observed. Lymphocyte stimulation by herpes simplex virus infected fibroblasts (and by CMV-infected fibroblasts in CMV-positive patients) in contrast remained high and even increased after BMT in both groups. These data indicate that T cell recovery after autologous BMT is mainly due to proliferation of mature T cells present in the BM graft and not to generation of new T cells from T cell precursors.  相似文献   
34.
35.
36.
37.
38.
39.
40.

Background  

The costs of arm, shoulder and neck symptoms are high. In order to decrease these costs employers implement interventions aimed at reducing these symptoms. One frequently used intervention is the RSI QuickScan intervention programme. It establishes a risk profile of the target population and subsequently advises interventions following a decision tree based on that risk profile. The purpose of this study was to perform an economic evaluation, from both the societal and companies' perspective, of the RSI QuickScan intervention programme for computer workers. In this study, effectiveness was defined at three levels: exposure to risk factors, prevalence of arm, shoulder and neck symptoms, and days of sick leave.  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