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   41984篇
  免费   5383篇
  国内免费   196篇
耳鼻咽喉   679篇
儿科学   941篇
妇产科学   844篇
基础医学   4342篇
口腔科学   1120篇
临床医学   6474篇
内科学   9111篇
皮肤病学   557篇
神经病学   3849篇
特种医学   1381篇
外科学   7267篇
综合类   714篇
一般理论   24篇
预防医学   3874篇
眼科学   1269篇
药学   2311篇
中国医学   80篇
肿瘤学   2726篇
  2023年   598篇
  2022年   276篇
  2021年   777篇
  2020年   684篇
  2019年   716篇
  2018年   1290篇
  2017年   1245篇
  2016年   1170篇
  2015年   1261篇
  2014年   1773篇
  2013年   2220篇
  2012年   2430篇
  2011年   2466篇
  2010年   1699篇
  2009年   1788篇
  2008年   2275篇
  2007年   2354篇
  2006年   2519篇
  2005年   2471篇
  2004年   2268篇
  2003年   2284篇
  2002年   2147篇
  2001年   577篇
  2000年   462篇
  1999年   620篇
  1998年   756篇
  1997年   632篇
  1996年   662篇
  1995年   508篇
  1994年   485篇
  1993年   399篇
  1992年   429篇
  1991年   385篇
  1990年   323篇
  1989年   313篇
  1988年   287篇
  1987年   262篇
  1986年   263篇
  1985年   232篇
  1984年   266篇
  1983年   217篇
  1982年   248篇
  1981年   222篇
  1980年   178篇
  1979年   161篇
  1978年   165篇
  1977年   148篇
  1976年   111篇
  1974年   128篇
  1973年   121篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.

Aims

Drug treatments for obesity have proven efficacy from randomized trials, but their effectiveness in routine clinical practice is unknown. We assessed the effects on weight and body mass index (BMI) of orlistat and sibutramine when delivered in routine primary care.

Methods

We used United Kingdom data from the Clinical Practice Research Datalink to estimate the effects of orlistat or sibutramine on weight and BMI over 3 years following treatment initiation. For comparison, we matched each patient with up to five obese patients receiving neither drug. Mixed effects linear regression with splines was used to model change in weight and BMI. Mean change with 95% confidence intervals (CI) was estimated.

Results

We identified 100 701 patients receiving orlistat, 15 355 receiving sibutramine and 508 140 non-intervention patients, with body mass index of 37.2, 36.6 and 33.2 kg m−2, respectively. Patients receiving orlistat lost, on average, 0.94 kg month−1 (0.93 to 0.95) over the first 4 months. Weight gain then occurred, although weight remained slightly below baseline at 3 years. Patients receiving sibutramine lost, 1.28 kg month−1 (1.26 to 1.30) over the first 4 months, but by 3 years had exceeded baseline weight. Non-intervention patients had slight increases in weight throughout the 3 year period, with gains ranging between 0.01 and 0.06 kg month−1.

Conclusions

Orlistat and sibutramine had early effects on weight loss, not sustained over 3 years. As new treatments for obesity are approved, their effectiveness should be measured in routine clinical practice, as effectiveness may be considerably less than seen in randomized trials.  相似文献   
993.
According to the justification hypothesis, non‐employed individuals may over‐report their level of work limitation, leading to biased census/survey estimates of the prevalence of severe disabilities and the associated labor force participation rate. For researchers studying policies which impact the disabled or elderly (e.g., Supplemental Security Income, Disability Insurance, and Early Retirement), this could lead to significant bias in key parameters of interest. Using the American Community Survey, we examine the potential for both inflated and deflated reported disability status and generate a general index of disability, which can be used to reduce the bias of these self‐reports in other studies. We find that at least 4.8 million individuals have left the labor force because of a work‐limiting disability, at least four times greater than the impact implied by our replication of previous models. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
994.
995.

Background

Genetic carrier screening is increasingly possible for many conditions, but it is important to ensure decisions are informed. The multidimensional measure of informed choice (MMIC) is a quantitative instrument developed to evaluate informed choice in prenatal screening for Down syndrome, measuring knowledge, attitudes and uptake. To apply the MMIC in other screening settings, the knowledge scale must be modified.

Objective

To develop and validate a modified MMIC knowledge scale for use with women undergoing carrier screening for fragile X syndrome (FXS).

Setting and participants

Responses to MMIC items were collected through questionnaires as part of a FXS carrier screening pilot study in a preconception setting in Melbourne, Australia.

Design

Ten knowledge scale items were developed using a modified Delphi technique. Cronbach''s alpha and factor analysis were used to validate the new FXS knowledge scale. We summarized the knowledge, attitudes and informed choice status based on the modified MMIC.

Results

Two hundred and eighty‐five women were recruited, 241 eligible questionnaires were complete for analysis. The FXS knowledge scale items measured one salient construct and were internally consistent (alpha = 0.70). 71% (172/241) of participants were classified as having good knowledge, 70% (169/241) had positive attitudes and 27% (65/241) made an informed choice to accept or decline screening.

Discussion and conclusions

We present the development of a knowledge scale as part of a MMIC to evaluate informed choice in population carrier screening for FXS. This can be used as a template by other researchers to develop knowledge scales for other conditions for use in the MMIC.  相似文献   
996.
997.
998.

Background

The quality of shared decision making for children with serious illness may depend on whether parents and physicians share similar perceptions of problems and hopes for the child.

Objective

(i) Describe the problems and hopes reported by mothers, fathers and physicians of children receiving palliative care; (ii) examine the observed concordance between participants; (iii) examine parental perceived agreement; and (iv) examine whether parents who identified specific problems also specified corresponding hopes, or whether the problems were left ‘hopeless’.

Method

Seventy‐one parents and 43 physicians were asked to report problems and hopes and perceived agreement for 50 children receiving palliative care. Problems and hopes were classified into eight domains. Observed concordance was calculated between parents and between each parent and the physicians.

Results

The most common problem domains were physical body (88%), quality of life (74%) and medical knowledge (48%). The most common hope domains were quality of life (88%), suffering (76%) and physical body (39%). Overall parental dyads demonstrated a high percentage of concordance (82%) regarding reported problem domains and a lower percentage of concordance on hopes (65%). Concordance between parents and physicians regarding specific children was lower on problem (65–66%) and hope domains (59–63%). Respondents who identified problems regarding a child's quality of life or suffering were likely to also report corresponding hopes in these domains (93 and 82%, respectively).

Conclusion

Asking parents and physicians to talk about problems and hopes may provide a straightforward means to improve the quality of shared decision making for critically ill children.  相似文献   
999.
1000.
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