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   2891192篇
  免费   225925篇
  国内免费   5307篇
耳鼻咽喉   41279篇
儿科学   90330篇
妇产科学   75602篇
基础医学   416809篇
口腔科学   82618篇
临床医学   265164篇
内科学   558978篇
皮肤病学   59699篇
神经病学   235501篇
特种医学   113950篇
外国民族医学   1003篇
外科学   435125篇
综合类   67440篇
现状与发展   3篇
一般理论   1135篇
预防医学   231190篇
眼科学   68209篇
药学   217965篇
  7篇
中国医学   6194篇
肿瘤学   154223篇
  2018年   29856篇
  2017年   23068篇
  2016年   25491篇
  2015年   28668篇
  2014年   40903篇
  2013年   62239篇
  2012年   83687篇
  2011年   88389篇
  2010年   52111篇
  2009年   49561篇
  2008年   83565篇
  2007年   89249篇
  2006年   90231篇
  2005年   87271篇
  2004年   84360篇
  2003年   81087篇
  2002年   79954篇
  2001年   135364篇
  2000年   139646篇
  1999年   117659篇
  1998年   33551篇
  1997年   30168篇
  1996年   30122篇
  1995年   29001篇
  1994年   27169篇
  1993年   25307篇
  1992年   94701篇
  1991年   92060篇
  1990年   89196篇
  1989年   86287篇
  1988年   80015篇
  1987年   78548篇
  1986年   74497篇
  1985年   70846篇
  1984年   53458篇
  1983年   45465篇
  1982年   27179篇
  1981年   24260篇
  1979年   49987篇
  1978年   35217篇
  1977年   29620篇
  1976年   28066篇
  1975年   29754篇
  1974年   36403篇
  1973年   34550篇
  1972年   32438篇
  1971年   29924篇
  1970年   28294篇
  1969年   26291篇
  1968年   23991篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
23.
24.

Background

Nursing Home Compare (NHC) ratings, created and maintained by Medicare, are used by both hospitals and consumers to aid in the skilled nursing facility (SNF) selection process. To date, no studies have linked NHC ratings to actual episode-based outcomes. The purpose of this study was to evaluate whether NHC ratings are valid predictors of 90-day complications, readmission, and bundle costs for patients discharged to an SNF after primary total joint arthroplasty (TJA).

Methods

All SNF-discharged primary TJA cases in 2017 at a multihospital academic health system were queried. Demographic, psychosocial, and clinical variables were manually extracted from the health record. Medicare NHC ratings were then collected for each SNF. For patients in the Medicare bundle, postacute and total bundle cost was extracted from claims.

Results

Four hundred eighty-eight patients were discharged to a total of 105 unique SNFs. In multivariate analysis, overall NHC rating was not predictive of 90-day readmission/major complications, >75th percentile postacute cost, or 90-day bundle cost exceeding the target price. SNF health inspection and quality measure ratings were also not predictive of 90-day readmission/major complications or bundle performance. A higher SNF staffing rating was independently associated with a decreased odds for >75th percentile 90-day postacute spend (odds ratio, 0.58; P = .01) and a 90-day bundle cost exceeding the target price (odds ratio = 0.69; P = .02) but was similarly not predictive of 90-day readmission/complications.

Conclusion

Results of our study suggest that Medicare's NHC tool is not a useful predictor of 90-day costs, complications, or readmissions for SNFs within our health system.  相似文献   
25.
Introduction: Tamoxifen dominates the anti-estrogenic therapy in the early and metastatic breast cancer setting. Tamoxifen has a complex metabolism, being mainly metabolized by CYP2D6 into its 30–100 times more potent metabolite, endoxifen. Recently, a phase I study in which endoxifen as an orally z-endoxifen hydrochloride has been successfully evaluated.

Areas covered: the principal pharmacogenetic and non-genetic differences in the pharmacology of tamoxifen and endoxifen are evaluated. To this end, references from PubMed, Embase or Web of Science, among others, were reviewed As non-genetic factors, important differences and similarities such age, or adherence to tamoxifen therapy are comprehensively illustrated. Additionally, since CYP2D6 genotypes are considered the main limitation of tamoxifen, many studies have investigated the association between the worsened clinical outcomes in patients with non-functional CYP2D6 genotypes. In this review, an overview of the research on this field is presented. Also, a summary describing the literature about individualizing tamoxifen therapy with endoxifen concentrations and its limitations is listed.

Expert opinion: z-endoxifen hydrochloride is only investigated in the metastatic setting, still more research is required before its place in therapeutics is known. Similarly, monitoring tamoxifen efficacy based on endoxifen concentrations might not be overall recommended due to the limited evidence available.  相似文献   

26.
27.
28.
ABSTRACT

Forest workers, including loggers, foresters, and wildland firefighters, are regularly exposed to some of the most fatal occupational environments in the United States. These hazardous work environments may become even more complex and dynamic when subject to bark beetle outbreaks that have resulted in significant tree mortality. The impacts of tree death from bark beetles are significant, with the cumulative 17-year (2000–2016) footprint for bark beetle caused tree mortality estimated at 54 million acres. However, how workers think about and act in these environments is understudied. This study, therefore, approaches the issue of beetle kill and forest worker safety by examining the perspectives or workers themselves. Its contribution is to leverage ethnographic research to provide insights that can generate new research questions, better inform outreach, and ultimately improve worker safety outcomes. The resulting insights show that beetle kill was understood by workers as a hazard that increased the complexity and dynamism of the work environment, making situational awareness both more necessary and more difficult to maintain. While much research about situational awareness focuses on hazardous situations, it is suggested that building adequate situational awareness should also include broader considerations of organizational communication, as well as training and experience considered over the course of entire careers.  相似文献   
29.
30.
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