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   7695篇
  免费   560篇
  国内免费   11篇
耳鼻咽喉   77篇
儿科学   295篇
妇产科学   204篇
基础医学   1049篇
口腔科学   89篇
临床医学   1002篇
内科学   1297篇
皮肤病学   123篇
神经病学   876篇
特种医学   143篇
外科学   792篇
综合类   42篇
一般理论   9篇
预防医学   1031篇
眼科学   107篇
药学   490篇
中国医学   4篇
肿瘤学   636篇
  2024年   18篇
  2023年   97篇
  2022年   139篇
  2021年   310篇
  2020年   193篇
  2019年   301篇
  2018年   356篇
  2017年   214篇
  2016年   238篇
  2015年   277篇
  2014年   371篇
  2013年   481篇
  2012年   720篇
  2011年   687篇
  2010年   373篇
  2009年   305篇
  2008年   509篇
  2007年   531篇
  2006年   462篇
  2005年   444篇
  2004年   348篇
  2003年   288篇
  2002年   257篇
  2001年   40篇
  2000年   27篇
  1999年   32篇
  1998年   57篇
  1997年   40篇
  1996年   25篇
  1995年   23篇
  1994年   13篇
  1993年   22篇
  1992年   14篇
  1991年   8篇
  1990年   5篇
  1989年   5篇
  1988年   3篇
  1987年   3篇
  1986年   4篇
  1984年   5篇
  1983年   1篇
  1982年   4篇
  1981年   4篇
  1979年   1篇
  1978年   4篇
  1976年   1篇
  1975年   2篇
  1972年   1篇
  1970年   1篇
  1968年   1篇
排序方式: 共有8266条查询结果,搜索用时 15 毫秒
31.
32.
33.
Studies have been made on attitudes to and experiences of women and men who have undergone pre-implantation genetic diagnosis (PGD), or who are regarded as potential users of this diagnostic method. Few studies have been conducted regarding the attitudes to and experiences of medical professionals as regards PGD. This paper reports on findings from such a qualitative study in which 18 semi-structured interviews were performed with geneticists and gynaecologists in Italy, Sweden and the UK. Interviewees emphasized, among other things, the importance of choice provision. Interviewees also told stories that indicated the many ways through which choice was feared to be hampered - or was hampered. A similar emphasis on the importance of PGD as one more alternative to choose between, for 'high-risk' couples, is not found in studies on the experiences, attitudes and views of potential, or actual, users of PGD.  相似文献   
34.
High-NA light sheet illumination can improve the resolution of single-molecule localization microscopy (SMLM) by reducing the background fluorescence. These approaches currently require custom-made sample holders or additional specialized objectives, which makes the sample mounting or the optical system complex and therefore reduces the usability of these approaches. Here, we developed a single-objective lens-inclined light sheet microscope (SOLEIL) that is capable of 2D and 3D SMLM in thick samples. SOLEIL combines oblique illumination with point spread function PSF engineering to enable dSTORM imaging in a wide variety of samples. SOLEIL is compatible with standard sample holders and off-the-shelve optics and standard high NA objectives. To accomplish optimal optical sectioning we show that there is an ideal oblique angle and sheet thickness. Furthermore, to show what optical sectioning delivers for SMLM we benchmark SOLEIL against widefield and HILO microscopy with several biological samples. SOLEIL delivers in 15 μm thick Caco2-BBE cells a 374% higher intensity to background ratio and a 54% improvement in the estimated CRLB compared to widefield illumination, and a 184% higher intensity to background ratio and a 20% improvement in the estimated CRLB compared to HILO illumination.  相似文献   
35.
Bacteria possess the ability to evolve varied and ingenious strategies to outwit the host immune system, instigating an evolutionary arms race. Proteases are amongst the many weapons employed by bacteria, which specifically cleave and neutralize key signalling molecules required for a coordinated immune response. In this article, we focus on a family of S8 subtilisin-like serine proteases expressed as cell-envelope proteases (CEPs) by group A and group B streptococci. Two of these proteases known as Streptococcus pyogenes CEP (SpyCEP) and C5a peptidase cleave the chemokine CXCL8 and the complement fragment C5a, respectively. Both CXCL8 and C5a are potent neutrophil-recruiting chemokines, and by neutralizing their activity, streptococci evade a key defence mechanism of innate immunity. We review the mechanisms by which CXCL8 and C5a recruit neutrophils and the characterization of SpyCEP and C5a peptidase, including both in vitro and in vivo studies. Recently described structural insights into the function of this CEP family are also discussed. We conclude by examining the progress of prototypic vaccines incorporating SpyCEP and C5a peptidase in their preparation. Since streptococci-producing SpyCEP and C5a peptidase are responsible for a considerable global disease burden, targeting these proteases by vaccination strategies or by small-molecule antagonists should provide protection from and promote the resolution of streptococcal infections.  相似文献   
36.
Arsenic is measurable in tobacco and cigarette mainstream smoke (MSS). Whether arsenic has an independent role in diseases associated with tobacco consumption is not known. Epidemiology and biomonitoring data and probabilistic risk assessment (PRA) methods were used to investigate this potential association. Analysis of data from the National Health and Nutrition Examination Survey (NHANES) showed that urine arsenic concentrations in tobacco consumers were not different or were lower than levels in non-consumers of tobacco. Additionally, urine arsenic levels from NHANES tobacco consumers were five-times or more lower than levels reported in epidemiology studies to be associated with adverse health effects. Results of PRA indicated that mean non-cancer hazard estimates and mean incremental lifetime cancer risk estimates were within accepted ranges. Taken together, these results suggest that arsenic may not be independently associated with tobacco consumption or diseases related to tobacco consumption.  相似文献   
37.
Objective. To develop a definition of professional engagement, a list of professionally engaging and disengaging activities, and characteristics of those activities.Methods. A 2-round modified Delphi process was conducted using student pharmacists. The first round captured input while the second assessed agreement using a 5-point Likert scale.Results. A definition was created using the 3 items that reached consensus. All engaging characteristics reached consensus, and 25% (3/12) of the disengaging characteristics reached consensus. Lower rates of consensus were observed for activities, with 78% (7/9) of the professionally engaging and none of the disengaging activities reaching consensus.Conclusion. The findings of this study have implications for creating professionally engaging learning experiences for student pharmacists and suggest that ensuring activities contain certain professionally engaging characteristics may be more important than the activities themselves.  相似文献   
38.
39.
40.
Conflicting findings regarding the relations between thought-action fusion (TAF), religiosity, and obsessive compulsive disorder (OCD) may be due to a lack of clarity regarding the intent associated with the negative thoughts under consideration. In Study 1, we examined the perceptions of the immorality of intentional and unwanted morally-relevant thoughts (Moral TAF) and their relations with OCD symptoms, religiosity, and obsessive beliefs in a non-clinical sample. In Study 2, we randomly assigned participants to complete one of two versions of a previously used sentence neutralization task that was varied in terms of intent. Perception of the immorality of intentional negative thoughts but not unwanted negative thoughts was associated with Protestant/Catholic affiliation and greater prayer frequency, and perception of the immorality of unwanted thoughts was consistently associated with obsessive beliefs. Neither form of Moral TAF was associated with OCD symptoms. Further, reaction to the modified non-intentional neutralization task was associated with OCD symptoms, thought-action fusion, and scrupulosity, while reaction to the original intentional task was only associated with Moral TAF. Overall, the findings suggest that individuals differ in their perceptions of intentional versus unintentional thoughts. Perceptions of intentional morally-relevant thoughts appear related to religiosity, while perceptions of unintentional thoughts are likely to be of greater relevance to our understanding of OCD.  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