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   11892篇
  免费   1057篇
  国内免费   23篇
耳鼻咽喉   244篇
儿科学   300篇
妇产科学   462篇
基础医学   1301篇
口腔科学   423篇
临床医学   1072篇
内科学   2571篇
皮肤病学   339篇
神经病学   1042篇
特种医学   532篇
外国民族医学   2篇
外科学   1801篇
综合类   135篇
一般理论   6篇
预防医学   913篇
眼科学   360篇
药学   525篇
中国医学   7篇
肿瘤学   937篇
  2021年   170篇
  2020年   131篇
  2019年   183篇
  2018年   186篇
  2017年   157篇
  2016年   198篇
  2015年   209篇
  2014年   274篇
  2013年   379篇
  2012年   559篇
  2011年   604篇
  2010年   354篇
  2009年   287篇
  2008年   504篇
  2007年   579篇
  2006年   593篇
  2005年   571篇
  2004年   517篇
  2003年   499篇
  2002年   457篇
  2001年   297篇
  2000年   336篇
  1999年   301篇
  1998年   132篇
  1997年   128篇
  1996年   97篇
  1995年   88篇
  1994年   108篇
  1993年   93篇
  1992年   221篇
  1991年   235篇
  1990年   237篇
  1989年   214篇
  1988年   200篇
  1987年   188篇
  1986年   207篇
  1985年   209篇
  1984年   155篇
  1983年   142篇
  1982年   104篇
  1981年   97篇
  1980年   84篇
  1979年   157篇
  1978年   117篇
  1977年   118篇
  1976年   99篇
  1975年   105篇
  1974年   133篇
  1973年   112篇
  1972年   97篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Introduction Patients with cystic fibrosis (CF) are known to be at risk for early osteoporosis, and the mechanisms that mediate bone loss are still being delineated. The aim of the present investigation was to investigate if a correlation exists in these patients between skeletal measurements by dual-energy x-ray absorptiometry (DXA) and two anabolic factors, dehydroepiandrosterone (DHEA) and insulin-like growth factor I (IGF-I), and proresorptive factors such as the cytokines interleukin-1β, tumor necrosis factor α, and interleukin-6. Methods We studied 32 outpatients (18 females; mean age: 26.2 ± 7.9 years) at a tertiary care medical center. The subjects had venous samples obtained, underwent anthropometric and bone mineral density (BMD) measurements, and completed a health survey. Serum IGF-I concentrations were below the age-adjusted mean in 78% of the participants, and DHEA sulfate (DHEAS) concentrations were low in 72%. Serum concentrations of all cytokines were on the low side of normal; nonetheless, there was a modest inverse correlation between IL-1β and BMD at all sites. Results In univariate analyses, IGF-I and DHEAS were significant correlates of BMD or bone mineral content. In final multivariate models controlling for anthropometric and other variables of relevance to bone density, only IGF-I was identified as a significant independent skeletal predictor. While alterations in DHEAS, IGF-I, and specific cytokines may contribute to skeletal deficits in patients with CF, of these factors a low IGF-I concentration appears to be most strongly correlated with BMD. Conclusions These findings may have therapeutic implications for enhancing bone density in these patients.  相似文献   
7.
8.
We retrospectively reviewed our experience with immediate breast reconstruction in 103 consecutive patients with stage 0 or I breast carcinoma between May 1983 and April 1988. Two reconstructive techniques were used, that is, either tissue expansion with secondary prosthesis implantation (60%) or transverse rectus abdominis musculocutaneous (TRAM) flap (40%). Chemotherapy was administered in 22% of patients without delay or compromise. The mean length of follow-up is 30 months. The complication rate was equal for both groups (24%) with infection being most common in the group of patients with tissue expansion and partial flap necrosis being most common in the group of patients with TRAM flaps. Aesthetic results were superior with use of the TRAM flap. Our experience concurs with previous reports that documented satisfactory results with immediate breast reconstruction without compromising further therapy. We conclude that although the tissue expansion technique yields acceptable results, the TRAM flap yields superior aesthetic results in terms of both appearance and consistency.  相似文献   
9.
10.
PURPOSE: Chart notes are used to support billing codes under the evaluation and management guidelines of the Health Care Financing Administration (HCFA), in addition to serving as a record of the visit. To better understand the effect of the HCFA documentation guidelines, the authors collected data on how the guidelines affect participation by university- and community-based faculty in clinical education programs. METHOD: In 2000, the authors sent six copies of their questionnaire to the associate deans of the 125 U.S. medical schools and requested they distribute them to all core clerkship directors. The questionnaire consisted of multiple-choice and short-answer questions regarding documentation of medical visits, participation of community-based faculty, understanding of HCFA documentation guidelines, and effects on education programs. RESULTS: The response rate was about 50%. Most of the 379 clerkship directors who responded (77%) stated they were aware the HCFA documentation guidelines include specifications regarding the role medical students can play and documentation of medical visits, and 64% indicated they were concerned the guidelines would affect their educational programs. Concerns included the loss of student independence and active participation in the patient care environment (37), time constraints and the changing balance between education and service (16), loss of faculty and decreased morale (11), and decreased quality of care for patients (7). CONCLUSION: Leaders of medical education must work to modify these guidelines to protect the quality of patients' care, while maximizing students' educational opportunity and participation.  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