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   2751篇
  免费   251篇
  国内免费   2篇
耳鼻咽喉   33篇
儿科学   87篇
妇产科学   106篇
基础医学   314篇
口腔科学   102篇
临床医学   393篇
内科学   404篇
皮肤病学   59篇
神经病学   236篇
特种医学   74篇
外科学   441篇
综合类   138篇
一般理论   4篇
预防医学   323篇
眼科学   21篇
药学   169篇
中国医学   1篇
肿瘤学   99篇
  2021年   47篇
  2019年   58篇
  2018年   62篇
  2017年   49篇
  2016年   46篇
  2015年   45篇
  2014年   70篇
  2013年   65篇
  2012年   132篇
  2011年   127篇
  2010年   96篇
  2009年   73篇
  2008年   104篇
  2007年   91篇
  2006年   125篇
  2005年   134篇
  2004年   118篇
  2003年   120篇
  2002年   92篇
  2001年   74篇
  2000年   73篇
  1999年   68篇
  1998年   23篇
  1997年   33篇
  1996年   30篇
  1995年   21篇
  1994年   25篇
  1992年   44篇
  1991年   48篇
  1990年   49篇
  1989年   32篇
  1988年   45篇
  1987年   45篇
  1986年   45篇
  1985年   47篇
  1984年   30篇
  1983年   27篇
  1982年   23篇
  1979年   28篇
  1978年   27篇
  1977年   19篇
  1976年   22篇
  1974年   26篇
  1973年   20篇
  1972年   20篇
  1971年   19篇
  1970年   19篇
  1969年   26篇
  1968年   24篇
  1966年   30篇
排序方式: 共有3004条查询结果,搜索用时 140 毫秒
1.
2.

Introduction/Hypothesis

Recruitment of participants into phase 1 vaccine clinical trials can be challenging since these vaccines have not been used in humans and there is no perceived benefit to the participant. Occasionally, as was the case with a phase 1 clinical trial of an Ebola vaccine in Halifax, Canada, during the 2014–2016 West African Ebola virus outbreak, recruitment is less difficult. In this study, we explored the motivations of participants in two phase 1 vaccine trials that were concurrently enrolling at the same centre and compared the motivations of participants in a high-profile phase 1 Ebola vaccine trial to those in a less high-profile phase 1 adjuvanted seasonal influenza vaccine study.

Methods

An online survey which included participants’ prior experience with clinical trials, motivations to participate (including financial incentives), and demographic information was developed to examine the motivations of healthy participants in two phase 1 clinical vaccine trials conducted at the Canadian Center for Vaccinology in Halifax, Nova Scotia. Participants were invited via email to complete the online survey. Readability and clarity were assessed through pilot testing.

Results

A total of 49 (55.7%) of 88 participants of the two studies completed the survey (22 [55%] of 40 participants from the Ebola vaccine study and 27 [56.3%] of 48 from the adjuvanted influenza vaccine study). Motivations that were most frequently ranked among participants' top three in both trials were (1) wanting to contribute to the health of others, (2) wanting to participate in something important, (3) wanting to contribute to the advancement of science, and (4) wanting to receive an incentive such as money or a tablet.

Conclusions/Recommendations

Although media attention and financial compensation were more often cited by Ebola vaccine trial participants as a reason to participate, both altruistic and self-interested factors were important motivations for participants in their decision to participate in a phase 1 vaccine clinical trial.  相似文献   
3.
This is the third and final part of a series of articles that report the findings of a study that investigated the effects of a summer externship program on the transition into a professional role among nurses who participated in a summer nurse externship program at an acute care pediatric hospital. Specifically, this article reports the retention and recruitment benefits of a summer nurse externship program for the institution from 1998 through 2003. A total of 153 externs out of the 193 (79.0%) assumed a registered nurse position at the institution, and 77% remained in that role for 12 months. Overall, the nurse extern program for this institution appeared to be an effective recruitment and retention strategy that is on par with the institution and national data for retention and turnover data.  相似文献   
4.
OBJECTIVES: To pilot the acceptability and feasibility of clinical audit in free and pedicled flap reconstruction. To establish a baseline flap failure rate in participating units, so that a sample size calculation could be performed for future national audit. METHODS: A proforma was piloted over a 3-month period in four participating units, during which time data on 93 reconstructive procedures involving free and pedicled flaps was collected. The patients included those where large transfers of tissue were required such as for coverage of grade IIIb compound tibial fractures and breast reconstruction after mastectomy, and also smaller flap transfers such as after skin cancer excision. RESULTS: The proforma was found to be acceptable to clinicians and the feasibility of the data collection process was established. Overall there was a total flap survival of 89% and secondary operations to the donor or recipient sites were required in 11% of patients. CONCLUSIONS: This study demonstrates the feasibility of comparative audit for free and pedicled flap procedures using the methods proposed. Based on the incidence of flap failure observed in this pilot study, at least 18 months of prospective data collection on consecutive patients is required to fulfil the statistical requirements of comparative audit. The establishment of a routinely collected minimum dataset is proposed as one means of meeting these requirements.  相似文献   
5.
6.
7.
8.
N Weinzweig  E Z Browne 《Orthopedics》1988,11(7):1077-1078
The most common site of median nerve compression is in the carpal tunnel, the most common of all entrapment neuropathies. Less frequent entrapment neuropathies of the median nerve include the anterior interosseous and pronator syndromes in the proximal forearm. Even less commonly seen is entrapment at the infraclavicular segment of the brachial plexus. Median nerve compression at the level of the axilla has been reported as being caused by anomalous axillary arch muscles, anomalous vascular perforations of the nerve or its roots, the pectoralis minor muscle, and a thickening of the deltopectoral fascia. To the authors' knowledge, this is the first report of compression at that level by a benign tumor.  相似文献   
9.
10.
INTRODUCTION: Concern about the potential detrimental side-effects of beta-blockade on pulmonary function often dissuades against their perioperative use in patients undergoing major arterial surgery (especially in those with chronic obstructive pulmonary disease (COPD)). In this study we aimed to establish prospectively the clinical relevance of these concerns. METHODS: After ethics committee approval and individual informed consent, the pulmonary function of twenty patients (mean age 68.7 years (range 43-82), 11 males) scheduled to undergo non-emergency major vascular surgery was studied by recording symptoms and spirometry before and after institution of effective beta-blockade. Fifteen patients (75%) had significant smoking histories (mean pack years/patient=50), while 12 (60%) had COPD. RESULTS: All patients tolerated effective beta-blockade satisfactorily without developing either subjective deterioration in symptoms or significant change on spirometry. The mean change in FEV1 following adequate beta-blockade was 0.05+/-0.24 liters (95% CI -0.06 to +1.61), p=0.35, giving a mean percentage change of 3.18%+/-11.66 (95% CI -2.26 to 8.62). CONCLUSIONS: Previously held concerns about worsening pulmonary function through the short-term use of beta-blockers should not dissuade their perioperative usage in patients with peripheral vascular disease. Furthermore, the accuracy of pulmonary function tests in preoperative assessment and risk stratification also appears unaffected by this therapy.  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