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   14781篇
  免费   995篇
  国内免费   25篇
耳鼻咽喉   148篇
儿科学   576篇
妇产科学   387篇
基础医学   1773篇
口腔科学   131篇
临床医学   2202篇
内科学   2679篇
皮肤病学   164篇
神经病学   1553篇
特种医学   278篇
外科学   1328篇
综合类   158篇
一般理论   15篇
预防医学   2125篇
眼科学   318篇
药学   839篇
中国医学   11篇
肿瘤学   1116篇
  2024年   21篇
  2023年   135篇
  2022年   226篇
  2021年   533篇
  2020年   325篇
  2019年   493篇
  2018年   515篇
  2017年   382篇
  2016年   403篇
  2015年   414篇
  2014年   571篇
  2013年   864篇
  2012年   1188篇
  2011年   1316篇
  2010年   668篇
  2009年   580篇
  2008年   998篇
  2007年   1032篇
  2006年   988篇
  2005年   876篇
  2004年   772篇
  2003年   755篇
  2002年   644篇
  2001年   69篇
  2000年   48篇
  1999年   77篇
  1998年   121篇
  1997年   88篇
  1996年   64篇
  1995年   66篇
  1994年   63篇
  1993年   50篇
  1992年   39篇
  1991年   36篇
  1990年   29篇
  1989年   25篇
  1988年   27篇
  1987年   16篇
  1986年   24篇
  1985年   29篇
  1984年   25篇
  1983年   19篇
  1982年   26篇
  1981年   31篇
  1980年   28篇
  1979年   10篇
  1978年   11篇
  1977年   9篇
  1976年   9篇
  1974年   8篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
Red cell exchange (RCE) is a common procedure in adults with sickle cell disease (SCD). Implantable dual lumen Vortex (DLV) ports can be used for RCE in patients with poor peripheral venous access. We performed a retrospective cohort study of RCE procedures performed in adults with SCD. The main objective of the study was to compare the inlet speed, duration of procedures and rate of complications performed through DLV ports to those performed through temporary central venous and peripheral catheters. Twenty‐nine adults with SCD underwent a total of 318 RCE procedures. Twenty adults had DLV ports placed and 218 procedures were performed using DLV ports. Mean length of follow‐up after DLV port placement was 397 ± 263 days. Six DLV ports were removed due to infection and 1 for malfunction after a mean of 171 ± 120 days. Compared to temporary central venous and peripheral catheters, DLV port procedures had a greater rate of procedural complications, a longer duration, and a lower inlet speed (all P < 0.01). When accounting for the maximum allowable inlet speed to avoid citrate toxicity, 40% of DLV port procedures were greater than 10% below maximum speed, compared to 7 and 14% of procedures performed through temporary central venous and peripheral catheters (P < 0.0001). In conclusion, DLV ports can be used for RCE in adults with SCD, albeit with more procedural complications and longer duration. The smaller internal diameter and longer catheter of DLV ports compared to temporary central venous catheters likely accounts for the differences noted. J. Clin. Apheresis 30:353–358, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   
4.
5.
6.
7.
8.
BACKGROUND: Physical activity is a healthful behavior that has promise for combating feelings of low energy and fatigue. Despite evidence suggesting that fatigue is a prodromal symptom of major cardiac events, improvements in feelings of energy and fatigue have largely been ignored by reviewers of cardiac rehabilitation literature who have focused on anxiety, depression and general measures of quality of life. DESIGN: A meta-analytical review. METHODS AND RESULTS: Computer databases were searched from January 1945 to May 2005 to identify relevant literature. A total of 36 studies consisting of 4765 subjects were included. Cardiac rehabilitation exercise programs were consistently associated with increases in energy and decreases in fatigue. The magnitude of the effect was moderately large (mean delta 0.51; 95% confidence interval 0.42-0.61) but was heterogeneous and modified by features of the research design. Comparison of effect sizes in cardiac rehabilitation studies concurrently measuring energy/fatigue, anxiety and depression suggest that exercise-based cardiac rehabilitation programs have larger effects on feelings of energy and fatigue compared with anxiety and depression. CONCLUSION: This review quantifies the potential benefit of cardiac rehabilitation exercise programs on feelings of energy and fatigue, and suggests that cardiac rehabilitation researchers and practitioners may benefit from examining, and perhaps even focusing on, feelings of energy and fatigue as an important outcome variable. A greater understanding of the effect of cardiac rehabilitation exercise programs on feelings of energy and fatigue will be reached when more true experiments are conducted thereby avoiding the primary limitation of the literature reviewed; that is, the frequent use of non-experimental research designs.  相似文献   
9.
Fibromyalgia is a syndrome of widespread pain, nonrestorative sleep, disturbed mood, and fatigue. Optimal treatment involves a multidisciplinary approach with a team of health care providers using pharmacologic and nonpharmacologic treatment. Because of the heterogeneity of the illness, management should be individualized for the patient. Pharmacologic treatment should address issues of pain control, sleep disturbance, fatigue, and any underlying coexisting mood disorder. Nonpharmacologic treatment should include patient education, a regular exercise and stretching program, and cognitive behavioral therapy. All of these are essential to improving functional capacity and quality of life. This review provides general guidelines in initiating a successful pharmacologic treatment program for patients with fibromyalgia.  相似文献   
10.
BACKGROUND: Until there is a definitive demonstration that early diagnosis and treatment of prostate cancer reduces disease-related mortality, it is imperative to promote informed screening decisions by providing balanced information about the potential benefits and risks of prostate cancer screening. Within a community/academic collaboration, we conducted a randomized trial of a printed booklet and a videotape that were designed for African American (AA) men. The purpose of the trial was to determine the effect of the interventions on knowledge, decisional conflict, satisfaction with the screening decision, and self-reported screening. METHODS: Participants were 238 AA men, ages 40 to 70 years, who were members of the Prince Hall Masons in Washington, DC. Men were randomly assigned to the (a) video-based information study arm, (b) print-based information study arm, or (c) wait list control study arm. Intervention materials were mailed to men at home. Assessments were conducted at baseline, 1 month, and 12 months postintervention. Multivariate analyses, including ANCOVA and logistic regression, were used to analyze group differences. RESULTS: The booklet and video resulted in a significant improvement in knowledge and a reduction in decisional conflict about prostate cancer screening, relative to the wait list control. Satisfaction with the screening decision was not affected by the interventions. Self-reported screening rates increased between the baseline and the 1-year assessment, although screening was not differentially associated with either of the interventions. In exploratory analyses, prostate-specific antigen testing at 1 year was more likely among previously screened men and was associated with having low baseline decisional conflict. CONCLUSIONS: This study represents one of the first randomized intervention trials specifically designed to address AA men's informed decision making about prostate cancer screening. We have developed and evaluated culturally sensitive, balanced, and disseminable materials that improved knowledge and reduced decisional conflict about prostate cancer screening among AA men. Due to the high incidence and mortality rates among AA men, there is a need for targeted educational materials, particularly materials that are balanced in terms of the benefits and risks of screening.  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