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   2682篇
  免费   140篇
  国内免费   6篇
耳鼻咽喉   18篇
儿科学   69篇
妇产科学   145篇
基础医学   405篇
口腔科学   77篇
临床医学   259篇
内科学   606篇
皮肤病学   19篇
神经病学   211篇
特种医学   53篇
外科学   402篇
综合类   18篇
预防医学   160篇
眼科学   45篇
药学   139篇
中国医学   1篇
肿瘤学   201篇
  2023年   6篇
  2022年   12篇
  2021年   45篇
  2020年   29篇
  2019年   33篇
  2018年   53篇
  2017年   44篇
  2016年   63篇
  2015年   63篇
  2014年   114篇
  2013年   97篇
  2012年   145篇
  2011年   163篇
  2010年   110篇
  2009年   95篇
  2008年   197篇
  2007年   204篇
  2006年   184篇
  2005年   199篇
  2004年   151篇
  2003年   168篇
  2002年   144篇
  2001年   42篇
  2000年   27篇
  1999年   33篇
  1998年   24篇
  1997年   32篇
  1996年   39篇
  1995年   25篇
  1994年   20篇
  1993年   19篇
  1992年   17篇
  1991年   11篇
  1990年   16篇
  1989年   15篇
  1988年   13篇
  1987年   12篇
  1986年   16篇
  1985年   14篇
  1984年   12篇
  1983年   10篇
  1982年   15篇
  1981年   13篇
  1980年   9篇
  1979年   8篇
  1978年   12篇
  1977年   9篇
  1973年   7篇
  1971年   7篇
  1969年   8篇
排序方式: 共有2828条查询结果,搜索用时 15 毫秒
61.
Background: Currently, in the field of rheumatology, there is much attention given towards the possible causality between periodontitis and rheumatoid arthritis (RA), specifically regarding the role of Porphyromonas gingivalis (Pg). This bacterium is unique, having a citrullinating enzyme. Antibodies against citrullinated proteins are rather specific for RA. Methods: Because causality is ultimately tested in longitudinal cohort studies which currently do not exist for periodontitis and RA, this commentary applied Bradford Hill criteria on the existing literature to assess causality as the most likely interpretation of this association. Conclusions: From an epidemiologic point of view, patients with RA have a higher incidence of periodontal disease than individuals without RA. In addition, there is a dose‐response pattern in the association between the severity of periodontitis and RA disease activity. There are indications that periodontitis precedes RA, but there is no evidence yet available to show that Pg plays a direct role in this temporal relationship. The role of the unique characteristic of citrullination by Pg remains unexplained. However, in animal models, citrullination by Pg plays a distinct role in the development and aggravation of experimental arthritis. Although the role of Pg in RA remains speculative, a causative role for periodontitis as a chronic inflammatory disease caused by infectious agents in RA seems biologically plausible.  相似文献   
62.
63.
Idiopathic pulmonary fibrosis (IPF) is an age-related fatal disease with unknown etiology and no effective treatment. In this study, we show that primary cultures of fibroblasts derived from lung biopsies of IPF patients exhibited (i) accelerated replicative cellular senescence (CS); (ii) high resistance to oxidative-stress-induced cytotoxicity or CS; (iii) a CS-like morphology (even at the proliferative phase); and (iv) rapid accumulation of senescent cells expressing the myofibroblast marker α-SMA. Our findings suggest that CS could serve as a bridge connecting lung aging and its quite frequent outcome -- pulmonary fibrosis, and be an important player in the disease progression. Consequently, targeting senescent cells offers the potential of being a promising therapeutic approach.  相似文献   
64.
The experts concluded that current data show that the average nurse staffing levels (for RNs, LVN/LPNs, and NAs) in nursing homes are too low in some facilities to provide high quality of care. Caregiving, the central feature of a nursing home, needs to be improved to ensure high quality of care to residents. Because detailed time studies have not been conducted on the amount of time that is required to provide high quality of care to residents, expert opinion is currently the best approach to addressing the problem of inadequate staffing. Increases in the education level and training of nursing staff are also strongly recommended as a step to improving quality of care and reducing turnover rates in nursing homes. These recommendations are designed for consideration by Congress, HCFA regulators, policymakers, nursing home administrators, and nurses. Ideally, Congress would pass legislation establishing these recommendations as minimum standards for all nursing homes or direct HCFA to establish detailed minimum nurse staffing standards to ensure that staffing levels take into account the number and the case-mix of the residents. Alternatively, HCFA could introduce minimum staffing standards through the regulatory process. In 1999 there were a number of efforts at the state level to increase minimum staffing levels. Mohler (1999) surveyed selected states and found that 21 states had either proposed new legislation or were considering proposals for new legislation or new regulations. In California, for example, in 1999 the state budget approved $31 million in new state funds (to be matched with $31 million in federal Medicaid dollars) to increase nursing home staffing minimum requirements from 2.8 to 3.2 hr per resident day and to increase wage rates. Overall, nursing facilities need to be held accountable by HCFA for providing adequate levels and types of staffing to meet the needs of their residents, especially because government is paying for 61% of the expenditures. Adopting these minimum standards will have an important impact on improving the quality of the nation's nursing home care. Additional research is needed to determine appropriate levels and types of staff to provide high quality of care to residents. These studies could test the proposed staffing standards against existing staffing levels to examine the impacts on quality. As new data become available on staffing levels, revisions of staffing standards should be made if necessary to ensure that high standards are maintained.  相似文献   
65.
66.
67.
68.
Type 2 diabetes mellitus is very prevalent among persons aged 60–80 years old. This population is expected to increase in number and is characterized by the presence of comorbidities, long standing diabetes, frailty, high rate of cognitive impairment and limited life expectancy. These characteristics have a significant impact on diabetes and treatment among the elderly, much as diabetes predisposes to these conditions. In this article we will describe mechanisms that may lead to insulin resistance and diabetes among the elderly and also how these conditions contribute to the development of frailty and cognitive impairment. Hypoglycemia and it's consequences are important considerations when planning the treatment of diabetes. Treatment options in light of new goals and the danger of hypoglycemia will be detailed. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
69.
70.
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