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   31698篇
  免费   3006篇
  国内免费   53篇
耳鼻咽喉   368篇
儿科学   1084篇
妇产科学   681篇
基础医学   4544篇
口腔科学   536篇
临床医学   3318篇
内科学   6054篇
皮肤病学   427篇
神经病学   3128篇
特种医学   1097篇
外国民族医学   3篇
外科学   4030篇
综合类   784篇
一般理论   43篇
预防医学   3193篇
眼科学   945篇
药学   2397篇
中国医学   26篇
肿瘤学   2099篇
  2021年   411篇
  2020年   330篇
  2019年   485篇
  2018年   510篇
  2017年   420篇
  2016年   451篇
  2015年   540篇
  2014年   771篇
  2013年   1133篇
  2012年   1618篇
  2011年   1701篇
  2010年   870篇
  2009年   868篇
  2008年   1489篇
  2007年   1661篇
  2006年   1596篇
  2005年   1603篇
  2004年   1584篇
  2003年   1390篇
  2002年   1425篇
  2001年   841篇
  2000年   862篇
  1999年   820篇
  1998年   436篇
  1997年   330篇
  1996年   374篇
  1995年   310篇
  1994年   283篇
  1993年   282篇
  1992年   601篇
  1991年   609篇
  1990年   582篇
  1989年   575篇
  1988年   506篇
  1987年   509篇
  1986年   518篇
  1985年   454篇
  1984年   390篇
  1983年   355篇
  1982年   270篇
  1981年   220篇
  1980年   202篇
  1979年   373篇
  1978年   265篇
  1977年   199篇
  1976年   203篇
  1975年   180篇
  1974年   207篇
  1973年   218篇
  1972年   189篇
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
1.
2.
3.
4.
5.

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   
6.
7.
8.
9.
ABSTRACT

Forensic DNA analysis is dependent on comparing the known and the unknown. Expand the number of known profiles, and the likelihood of a successful match increases. Forensic use of DNA is moving towards comparing samples of unknown origin with publicly available genetic data, such as the records held by genetic genealogy providers. Use of forensic genetic genealogy has yielded a number of recent high-profile successes but has raised ethical and privacy concerns. Navigating family trees is complex, even more so when combined with a comparison of genetic relationships. This intelligence-gathering process has led to occasional false leads, and its use also risks a public backlash, similar to concerns over Cambridge Analytica. A cautious approach to use of this technique is therefore warranted.  相似文献   
10.
To evaluate morbidity associated with surgical lengthening of the gastrocnemius, medical records were reviewed retrospectively for 126 patients (mean age, 49.7 years; range, 8-78 years) who had undergone open gastrocnemius recession. Ten patients had isolated recession; 116 had gastrocnemius recession with an additional foot or ankle procedure on the ipsilateral limb. During a mean follow-up period of 19 months (range, 6-50 months), all patients were examined for any postoperative complications associated with the recession. Complications were defined as the presence of postoperative infection, wound dehiscence, nerve problems, decreased muscle strength, scar problems, or calcaneus gait (overlengthening). Uncomplicated outcome was defined as absence of all these complications and return to regular activity, both occurring during a follow-up of at least 6 months. Postsurgical complications developed in 9 (6%) of the 126 patients: 6 (4%) had scar problems, 2 (1.33%) had wound dehiscence, 2 (1.33%) had infection, 3 (2%) had nerve problems, and 1 (0.67%) developed complex regional pain syndrome. No patient complained of either a limp or gait disturbance. Neither persistent decrease in muscle strength nor calcaneus gait was seen. These data suggest that the open gastrocnemius recession procedure has low associated morbidity.  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