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   1934篇
  免费   172篇
  国内免费   4篇
耳鼻咽喉   18篇
儿科学   78篇
妇产科学   19篇
基础医学   294篇
口腔科学   91篇
临床医学   148篇
内科学   457篇
皮肤病学   23篇
神经病学   205篇
特种医学   111篇
外科学   230篇
综合类   23篇
一般理论   5篇
预防医学   154篇
眼科学   37篇
药学   98篇
中国医学   6篇
肿瘤学   113篇
  2023年   20篇
  2022年   45篇
  2021年   66篇
  2020年   48篇
  2019年   67篇
  2018年   67篇
  2017年   45篇
  2016年   54篇
  2015年   49篇
  2014年   66篇
  2013年   91篇
  2012年   134篇
  2011年   128篇
  2010年   73篇
  2009年   59篇
  2008年   86篇
  2007年   84篇
  2006年   70篇
  2005年   88篇
  2004年   70篇
  2003年   70篇
  2002年   59篇
  2001年   22篇
  2000年   24篇
  1999年   27篇
  1998年   15篇
  1997年   17篇
  1995年   9篇
  1994年   9篇
  1993年   11篇
  1992年   17篇
  1991年   32篇
  1990年   28篇
  1989年   29篇
  1988年   31篇
  1987年   27篇
  1986年   17篇
  1985年   25篇
  1984年   22篇
  1982年   9篇
  1980年   10篇
  1979年   16篇
  1978年   14篇
  1976年   12篇
  1975年   13篇
  1974年   19篇
  1973年   16篇
  1971年   10篇
  1970年   8篇
  1969年   8篇
排序方式: 共有2110条查询结果,搜索用时 0 毫秒
81.
In many countries worldwide, health worker shortages are one of the main constraints in achieving population health goals. Financial-incentive programmes for return of service, whereby participants receive payments in return for a commitment to practise for a period of time in a medically underserved area, can alleviate local and regional health worker shortages through a number of mechanisms. First, they can redirect the flow of those health workers who would have been educated without financial incentives from well-served to underserved areas. Second, they can add health workers to the pool of workers who would have been educated without financial incentives and place them in underserved areas. Third, financial-incentive programmes may improve the retention in underserved areas of those health workers who participate in a programme, but who would have worked in an underserved area without any financial incentives. Fourth, the programmes may increase the retention of all health workers in underserved areas by reducing the strength of some of the reasons why health workers leave such areas, including social isolation, lack of contact with colleagues, lack of support from medical specialists and heavy workload.  相似文献   
82.
We previously observed a positive association between a history of trichomonosis, a sexually transmitted infection caused by the protozoan, Trichomonas vaginalis, and prostate cancer risk in the Health Professionals Follow‐up Study. To determine the reproducibility of this finding, we conducted a second, prospective investigation of trichomonosis and prostate cancer in the Prostate Cancer Prevention Trial. Participants were men (≥55 years of age) with no evidence of prostate cancer at enrollment (n = 18,882). Men were screened annually for prostate cancer, and if not diagnosed during the trial, were offered an end‐of‐study prostate biopsy. Cases were a sample of men diagnosed with prostate cancer on any biopsy after visit 2 or on their end‐of‐study biopsy (n = 616). Controls were men not diagnosed with prostate cancer during the trial or on their end‐of‐study biopsy (n = 616). Controls were frequency‐matched to cases by age, treatment arm, and family history of prostate cancer. Serum from visit 2 was tested for anti‐T. vaginalis IgG antibodies. No association was observed between T. vaginalis serostatus and prostate cancer. 21.5% of cases and 24.8% of controls had low seropositivity, and 15.2% and 15.0% had high seropositivity. Compared to seronegative men, the odds ratio of prostate cancer for men with low seropositivity was 0.83 [95% confidence interval (CI): 0.63–1.09), and that for men with high seropositivity was 0.97 (95% CI: 0.70–1.34). Given the original strong biologic rationale and potential for prevention, additional studies are warranted to help resolve discrepancies between study findings and to further investigate this hypothesis from a variety of different approaches. © 2008 Wiley‐Liss, Inc.  相似文献   
83.
84.
85.
86.
    
Sensitization to one or more non-specific lipid transfer proteins (nsLTPs), initially thought to exist mainly in southern Europe, is becoming accepted as a cause of allergic reactions to plant foods across Europe and beyond. The peach nsLTP allergen Pru p 3 is a dominant sensitizing allergen and peaches a common food trigger, although multiple foods can be involved. A frequent feature of reactions is the requirement for a cofactor (exercise, alcohol, non-steroidal anti-inflammatory drugs, Cannabis sativa) to be present for a food to elicit a reaction. The variability in the food and cofactor triggers makes it essential to include an allergy-focused diet and clinical history in the diagnostic workup. Testing on suspected food triggers should also establish whether sensitization to nsLTP is present, using purified or recombinant nsLTP allergens such as Pru p 3. The avoidance of known trigger foods and advice on cofactors is currently the main management for this condition. Studies on immunotherapy are promising, but it is unknown whether such treatments will be useful in populations where Pru p 3 is not the primary sensitizing allergen. Future research should focus on the mechanisms of cofactors, improving diagnostic accuracy and establishing the efficacy of immunotherapy.  相似文献   
87.
88.
    
Attentional processes are generally assumed to be involved in multiple object tracking (MOT). The attentional capture paradigm is regularly used to study conditions of attentional control. It has up to now not been used to assess influences of sudden onset distractor stimuli in MOT. We investigated whether attentional capture does occur in MOT: Are onset distractors processed at all in dynamic attentional tasks? We found that sudden onset distractors were effective in lowering probe detection, thus demonstrating attentional capture. Tracking performance as dependent measure was not affected. The attentional capture effect persisted in conditions of higher tracking load (Experiment 2) and was dramatically increased in lower presentation frequency of the onset distractor (Experiment 3). Tracking performance was shown to suffer only when onset distractors were presented serially with very short time gaps in between, thus effectively disturbing re-engaging attention on the tracking set (Experiment 4). We discuss that rapid dis- and re-engagement of the attention process on target objects and an additional more basic process that continuously provides location information allow managing strong disruptions of attention during tracking.  相似文献   
89.
    
A novel pestivirus species, termed Lateral-shaking Inducing Neuro-Degenerative Agent virus (LindaV), was discovered in a piglet-producing farm in Austria in 2015 related to severe congenital tremor cases. Since the initial outbreak LindaV has not been found anywhere else. In this study, we determined the seroprevalence of LindaV infections in the domestic pig population of Austria. A fluorophore labeled infectious cDNA clone of LindaV (mCherry-LindaV) was generated and used in serum virus neutralization (SVN) assays for the detection of LindaV specific neutralizing antibodies in porcine serum samples. In total, 637 sera from sows and gilts from five federal states of Austria, collected between the years 2015 and 2020, were analyzed. We identified a single serum showing a high neutralizing antibody titer, that originated from a farm (Farm S2) in the proximity of the initially affected farm. The analysis of 57 additional sera from Farm S2 revealed a wider spread of LindaV in this pig herd. Furthermore, a second LindaV strain originating from this farm could be isolated in cell culture and was further characterized at the genetic level. Possible transmission routes and virus reservoir hosts of this emerging porcine virus need to be addressed in future studies.  相似文献   
90.
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