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   4609篇
  免费   320篇
  国内免费   53篇
耳鼻咽喉   18篇
儿科学   85篇
妇产科学   99篇
基础医学   460篇
口腔科学   89篇
临床医学   850篇
内科学   599篇
皮肤病学   36篇
神经病学   267篇
特种医学   82篇
外科学   231篇
综合类   367篇
现状与发展   1篇
预防医学   1195篇
眼科学   28篇
药学   301篇
  1篇
中国医学   69篇
肿瘤学   204篇
  2024年   5篇
  2023年   73篇
  2022年   94篇
  2021年   166篇
  2020年   180篇
  2019年   160篇
  2018年   161篇
  2017年   161篇
  2016年   156篇
  2015年   136篇
  2014年   230篇
  2013年   491篇
  2012年   243篇
  2011年   242篇
  2010年   200篇
  2009年   225篇
  2008年   245篇
  2007年   245篇
  2006年   197篇
  2005年   162篇
  2004年   158篇
  2003年   126篇
  2002年   115篇
  2001年   81篇
  2000年   74篇
  1999年   61篇
  1998年   53篇
  1997年   47篇
  1996年   39篇
  1995年   36篇
  1994年   41篇
  1993年   34篇
  1992年   24篇
  1991年   29篇
  1990年   19篇
  1989年   21篇
  1988年   22篇
  1987年   14篇
  1986年   28篇
  1985年   26篇
  1984年   28篇
  1983年   11篇
  1982年   25篇
  1981年   15篇
  1980年   21篇
  1979年   11篇
  1978年   12篇
  1977年   7篇
  1976年   7篇
  1970年   5篇
排序方式: 共有4982条查询结果,搜索用时 15 毫秒
81.
Protection of the thiolate function of dimercaptosuccinic acid (DMSA) and ethylenedi‐l ‐cysteine diethyl ester (ECD) by S‐thiomethylation allowed automatic deprotection during technetium‐99m (99mTc) radiolabelling by direct reduction with stannous chloride dihydrate. Protection of the free thiolate group increased the stability of the ligands as well as deprotection during complexation, which resulted in the desired radiopharmaceuticals. The complexes obtained from the protected ligands were chromatographically (HPLC) and biologically compared with the corresponding 99mTc complexes of the unprotected ligands. The results suggest that the aforementioned method of protection by S‐thiomethylation could be utilized for the development of single‐vial DMSA and ECD kit. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
82.
《Global public health》2013,8(3):285-298
More than a decade of fighting in the Democratic Republic of the Congo (DRC) has resulted in extensive human rights abuses, of which sexual and gender-based violence (SGBV) is one of the most salient and disturbing features. This paper uses qualitative data, based on 10 focus groups with 86 women and men to better understand gendered community perspectives on SGBV and its consequences in South Kivu. We conclude that for many survivors, rape has consequences far beyond the physiological and psychological trauma associated with the attack. Respondents say sexual violence has become a societal phenomenon, in which the community isolation and shame experienced as a result of the attack become as important as concerns about the attack itself. Male focus group participants explain their own feelings of shame and anger associated with knowing their female relatives were raped. These findings highlight the complexity of community reintegration for survivors and identify a number of programmatic and policy implications, such as the need for counselling for survivors of sexual violence with their families as well as individually; the importance of income-generating training; and the need for improved justice mechanisms to bring perpetrators to justice.  相似文献   
83.
84.
Summary

Irradiation causes atheromatotic changes in the coronary arteries, leading to occlusion of these vessels. In two out of ten animals, E.C.G. changes were found, which were characteristic for a myocardial infarct. This was confirmed at necropsy. One example is given of a young patient in whom radiotherapy was the cause of fatal pulmonary and myocardial fibrosis.  相似文献   
85.
86.
Culturally appropriate health materials for consumers can be difficult to identify. Many federal resources exist to help support minority health initiatives. In addition, national nonprofit organizations and state agencies provide materials to address the health needs of African Americans, Hispanics/Latinos, Asian Americans, American Indians/Alaska Natives, and Native Hawaiians/Pacific Islanders. This listing offers an initial list of primary resources that librarians can use to address consumer health inquiries from the public.  相似文献   
87.
88.
Children and young people are seen as fundamental to the design and delivery of clinical research as active and reflective participants. In Europe, involvement of children and young people in clinical research is promoted extensively in order to engage young people in research as partners and to give them a voice to raise their own issues or opinions and for their involvement in planning and decision making in addition to learning research skills. Children and young people can be trained in clinical research through participation in young person advisory groups (YPAGs). Members of YPAGs assist other children and young people to learn about clinical research and share their experience and point of view with researchers, thereby possibly influencing all phases of research including the development and prioritization of research questions, design and methods, recruitment plans, and strategies for results dissemination. In the long term, the expansion of YPAGs in Europe will serve as a driving force for refining pediatric clinical research. It will help in a better definition of research projects according to the patients’ needs. Furthermore, direct engagement of children and young people in research will be favorable to both researchers and young people.  相似文献   
89.
数字化曲面体层标记位点放大率的实验研究   总被引:1,自引:1,他引:0  
目的:探讨数字化曲面体层(PTG)的标记位点放大率。方法:以曲面体层机颏托上的U型标记杆及以干燥下颌骨的正常摆放位置为参照,将种植用钢珠按牙弓形态进行唇舌向网点式排布,进行位点设置,按1-8区牙位排列放置钢珠,类似同心圆状辐射排列,位点间距10mm,逐点拍摄,进行投照后在PACS上高清晰显示屏进行测量所得图像的水平向及垂直向数值,对图像进行分析,得出放大率,再进行部位分析,构建体层域。结果:水平向放大率较垂直向为显著,U型标记杆覆盖范围为前牙及双尖牙区,其唇侧水平向放大率均小于1,舌侧水平向放大率均大于1,后磨牙区图像垂直向与水平向均为放大。结论:不同位置的钢珠图像放大率不同,坐标相交点即为同等放大率位置,即位于体层域中心,体层域为显示图像较为真实的扫描区域,体层域唇侧图像水平向缩窄舌侧图像水平向放大,而垂直向均显示放大,变化倍率以水平向为显著(P<0.01),以此来指导临床上对曲面体层片的判读。  相似文献   
90.
Food marketing to children is a powerful factor in the health of young people. In Canada, one proposed measure to protect young people is to ban all food and beverage marketing to children under age 13. Since policy initiatives should consider the voices of those directly impacted, we conducted focus groups with teenagers aged 12–14 – precisely those individuals who would be directly impacted by, or just over, the age threshold proposed. The majority of teenagers consulted were opposed to a ban on food marketing, framing food marketing as a way to meet their consumer needs. Such perspectives mirror the arguments made by the food industry, and suggest that teenagers’ self-identification as consumers trump questions of ethics or public health. Even though teenagers argue that marketing is often misleading, they do not view regulation as a solution – a view troubled by the fact that many of the teenagers underestimated their own vulnerability to marketing. The research points to the need for a more complex understanding of how food marketing messages are understood by teenagers, for a more robust media literacy education, and for the need to engage – not ignore – young people when it comes to issues of public health.  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