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   3955篇
  免费   370篇
  国内免费   6篇
耳鼻咽喉   48篇
儿科学   124篇
妇产科学   95篇
基础医学   497篇
口腔科学   94篇
临床医学   434篇
内科学   697篇
皮肤病学   73篇
神经病学   407篇
特种医学   145篇
外科学   610篇
综合类   61篇
一般理论   5篇
预防医学   389篇
眼科学   91篇
药学   244篇
中国医学   1篇
肿瘤学   316篇
  2022年   30篇
  2021年   57篇
  2020年   30篇
  2019年   41篇
  2018年   57篇
  2017年   50篇
  2016年   65篇
  2015年   64篇
  2014年   85篇
  2013年   117篇
  2012年   155篇
  2011年   193篇
  2010年   108篇
  2009年   106篇
  2008年   150篇
  2007年   159篇
  2006年   166篇
  2005年   157篇
  2004年   164篇
  2003年   134篇
  2002年   150篇
  2001年   142篇
  2000年   144篇
  1999年   114篇
  1998年   49篇
  1997年   49篇
  1996年   52篇
  1995年   47篇
  1994年   40篇
  1993年   56篇
  1992年   95篇
  1991年   99篇
  1990年   96篇
  1989年   97篇
  1988年   87篇
  1987年   86篇
  1986年   64篇
  1985年   67篇
  1984年   42篇
  1983年   43篇
  1979年   36篇
  1978年   36篇
  1977年   39篇
  1976年   38篇
  1975年   32篇
  1974年   33篇
  1973年   38篇
  1972年   33篇
  1971年   29篇
  1970年   29篇
排序方式: 共有4331条查询结果,搜索用时 15 毫秒
71.
For women with breast cancer in whom multiple Oncotype DX® Recurrence Scores (RS) are obtained, RS concordance utilizing current NCCN recommendations has not been evaluated. Patients with two or more RS were identified. RS were stratified by NCCN guidelines and compared for concordance. Twenty-four patients were evaluated. RS concordance varied by tumor type: 100% in the same tumor, 91.7% in multiple ipsilateral tumors, 71.4% in contralateral tumors, and 66.7% in in-breast recurrent tumors. RS concordance for multiple assays in the same patient is not high enough to omit Oncotype DX® testing for each tumor.  相似文献   
72.
The Covid-19 pandemic lockdown regulations caused retirement homes to temporarily ban in-person visitation potentially increasing the mental health risks of older people. An opportunity arose for a multistakeholder community collaboration to design a mental health program for older people. To evaluate the process of delivering a 12-week psychosocial program aimed at preventing loneliness, countering boredom, and providing older people in restricted settings with education about Covid-19 during the lockdown, in Durban, South Africa. A qualitative retrospective design was used. Data from two focus groups and six semistructured individual interviews conducted with stakeholders (volunteers, social workers, and residents) postproject were analyzed using reflexive thematic analysis. Stakeholders had varied experiences of the project, in terms of content, processes of engagement, and implementation, resulting in five themes. The study concluded with recommendations. A strong need exists for multistakeholder community collaborations when implementing a program where the context restricts physical access.  相似文献   
73.
Dissemination of new information to caregivers in ways that enhance the care they deliver is central to quality improvement in health care. This article describes several strategies that have been employed in one long-term care setting and discusses evidence of their success.  相似文献   
74.
An important aspect of primary care physician availability is the retention of physicians once they have located. While retention has been under-researched compared to recruitment, it is especially important in rural areas where physician shortages already exist. This study reports the results of a retention survey completed by 132 primary care physicians in rural eastern Kentucky. The survey sets up an objective, hypothetical retention scenario and asks physicians to respond to structured questions and to an open-ended question about factors not appearing in the survey. In response to the structured portion of the survey, physicians indicate that relief coverage is the most important factor in rural physician retention. A content analysis of 75 open-ended responses reveals that besides the other factors in the survey, "sociocultural integration" is the pre-eminent retention issue for rural practitioners. This article concludes that the role of the local rural community may be more important in retention than in recruitment. Finally, it is suggested that additional in-depth qualitative research be conducted within the local contexts to enhance the understanding of rural physician retention processes.  相似文献   
75.
Using triple colour fluorescent in-situ hybridization (FISH) we have evaluated, on a blind basis, the disomy level for chromosome 21 and the sex chromosomes in flow cytometric sorted sperm samples. There were no statistically significant differences in the disomy rates when comparing the sorted samples (either for X- or Y-bearing spermatozoa) with non-sorted samples. There were no diploid spermatozoa observed in any sample group after MicroSort processing.  相似文献   
76.
77.
There has been only one previous report of an intracardiac gastrinoma causing Zollinger-Ellison syndrome. In this communication we describe the successful surgical resection of a gastrinoma located in the interventricular septum using cardiopulmonary bypass, blood cardioplegia, and mild hypothermia. Preoperative evaluation and histologic examination of the resected tumor strongly suggest that this was a primary intracardiac gastrinoma.  相似文献   
78.
OBJECTIVES: To identify risk factors for injuries and other health problems occurring during or immediately after participation in a marathon. METHODS: A prospective cohort study was undertaken of participants in the 1993 Auckland Citibank marathon. Demographic data, information on running experience, training and injuries, and information on other lifestyle factors were obtained from participants before the race using an interviewer-administered questionnaire. Information on injuries and other health problems sustained during or immediately after the marathon were obtained by a self administered questionnaire. Logistic regression analyses were undertaken to identify significant risk factors for health problems. RESULTS: This study, one of only a few controlled epidemiological studies that have been undertaken of running injuries, has identified a number of risk factors for injuries and other health problems sustained in a marathon. Men were at increased risk of hamstring and calf problems, whereas women were at increased risk of hip problems. Participation in a marathon for the first time, participation in other sports, illness in the two weeks before the marathon, current use of medication, and drinking alcohol once a month or more, were associated with increased self reported risks of problems. While increased training seemed to increase the risk of front thigh and hamstring problems, it may decrease the risk of knee problems. There are significant but complex relations between age and risk of injury or health problem. CONCLUSIONS: This study has identified certain high risk subjects and risk factors for injuries and other health problems sustained in a marathon. In particular, subjects who have recently been unwell or are taking medication should weigh up carefully the pros and cons of participating.  相似文献   
79.
Background: The anticancer role of tumor necrosis factor-alpha (TNF-) has been limited by toxicity. These experiments evaluate blocking endogenous interferon-gamma (IFN-) activity to abrogate TNF- toxicity. Methods: C57Bl/6 mice bearing MCA 105 tumor were treated with TNF- and anti-IFN- antibody (Ab) to evaluate the effect on the acute lethality of TNF- and their efficacy as evaluated by tumor growth rate, tumor histology, and survival. Results: Anti-IFN- Ab decreased TNF- lethality. Anti-IFN- Ab alone increased tumor growth significantly more than did nonimmune IgG (p2<0.0001). Tumor-bearing mice that received nonimmune IgG and TNF- had slower tumor growth (p2<0.02) and a trend toward improved survival (p=0.07) compared with saline-treated controls. Anti-IFN- Ab abrogated the antitumor effect of TNF-, prevented acute tumor necrosis histologically, and resulted in tumor growth rate and host survival similar to that of controls. The findings in mice that received anti-IFN- Ab and high-dose TNF- were comparable with those in mice that received a lower, equitoxic dose of TNF- alone. Conclusions: Blocking endogenous IFN- accelerates tumor growth in this model and partially abrogates the toxic and antitumor activity of exogenous TNF- equally. This suggests that blocking endogenous IFN- activity is not a useful strategy for limiting TNF- treatment toxicity.Presented in part at the 45th Annual Cancer Symposium of The Society of Surgical Oncology, New York, New York, March 15–18, 1992.  相似文献   
80.
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