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   970篇
  免费   105篇
  国内免费   5篇
耳鼻咽喉   34篇
儿科学   29篇
妇产科学   33篇
基础医学   118篇
口腔科学   9篇
临床医学   149篇
内科学   162篇
皮肤病学   24篇
神经病学   89篇
特种医学   20篇
外科学   105篇
综合类   8篇
现状与发展   1篇
一般理论   1篇
预防医学   158篇
眼科学   17篇
药学   58篇
肿瘤学   65篇
  2024年   3篇
  2023年   17篇
  2022年   17篇
  2021年   36篇
  2020年   34篇
  2019年   49篇
  2018年   45篇
  2017年   48篇
  2016年   29篇
  2015年   35篇
  2014年   46篇
  2013年   80篇
  2012年   93篇
  2011年   88篇
  2010年   36篇
  2009年   31篇
  2008年   57篇
  2007年   61篇
  2006年   41篇
  2005年   48篇
  2004年   48篇
  2003年   32篇
  2002年   39篇
  2001年   2篇
  2000年   6篇
  1999年   3篇
  1998年   7篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   5篇
  1993年   1篇
  1992年   5篇
  1991年   3篇
  1990年   3篇
  1988年   2篇
  1987年   1篇
  1985年   2篇
  1984年   4篇
  1983年   2篇
  1982年   4篇
  1981年   2篇
  1973年   3篇
  1972年   5篇
  1971年   1篇
  1968年   1篇
  1963年   1篇
  1962年   1篇
排序方式: 共有1080条查询结果,搜索用时 15 毫秒
81.
The growth in the provision of counselling services in British primary care offers an opportunity for general practitioners (GPs) to refer patients to counsellors following bereavement. This study explores the factors that influence GPs referral decisions. Qualitative interviews were conducted with 50 GPs from two cities in southern UK. The study found that GPs draw on notions of abnormal bereavement in making referral decisions. Indicators of bereavement problems related to: the nature of the death; level of social support; and reaction to the death. GPs views about the types of patients likely to benefit from counselling were further criteria employed in referral decisions. The study indicated that consideration of these factors may discriminate against certain types of patients being referred. Further education in the range of psychological theories of bereavement may assist GPs in understanding their bereaved patients' experiences and in developing their skills in recognising abnormal reactions and making appropriate referrals.  相似文献   
82.
Elevated expression of Eph receptors has long been correlated with the growth of solid tumors. However, the functional role of this family of receptor tyrosine kinases in carcinogenesis and tumor angiogenesis has not been well characterized. Here we report that soluble EphA receptors inhibit tumor angiogenesis and tumor progression in vivo in the RIP-Tag transgenic model of vascular endothelial growth factor (VEGF)-dependent multistage pancreatic islet cell carcinoma. Soluble EphA receptors delivered either by a transgene or an osmotic minipump inhibited the formation of angiogenic islet, a premalignant lesion, and reduced tumor volume of solid islet cell carcinoma. EphA2-Fc or EphA3-Fc treatment resulted in decreased tumor volume but increased tumor and endothelial cell apoptosis in vivo. In addition, soluble EphA receptors inhibited VEGF and betaTC tumor cell-conditioned medium-induced endothelial cell migration in vitro and VEGF-induced cornea angiogenesis in vivo. A dominant negative EphA2 mutant inhibited--whereas a gain-of-function EphA2 mutant enhanced--tumor cell-induced endothelial cell migration, suggesting that EphA2 receptor activation is required for tumor cell-endothelial cell interaction. These data provide functional evidence for EphA class receptor regulation of VEGF-dependent tumor angiogenesis, suggesting that the EphA signaling pathway may represent an attractive novel target for antiangiogenic therapy in cancer.  相似文献   
83.
We have investigated synaptic function in the hippocampus in mice of different ages carrying a null mutation in the PrP gene. Experiments carried out in vivo and in vitro in two laboratories revealed no differences in the ability of juvenile and young adult control and PrP-null mice to express long-term potentiation, paired-pulse facilitation, or posttetanic potentiation in either the dentate gyrus or in the CA1 region. However, we found a significant reduction in the level of posttetanic potentiation and long-term potentiation in the CA1 region of aged PrP-null mice. These results are discussed in relationship to reported increased levels of oxidative stress in older PrP-null mice.  相似文献   
84.
85.
ObjectivesThe aim of this study was to evaluate the psychometric performance of the patient- and parent-reported measures in the International Consortium for Health Outcomes Measurement (ICHOM) Standard Set for Cleft Care, and to identify ways of improving concept coverage.MethodsData from 714 patients with cleft lip and/or palate, aged 8 to 9, 10 to 12.5, and 22 years were collected between November 2015 and April 2019 at Erasmus University Medical Center, Boston Children’s Hospital, Duke Children’s Hospital, and from participating sites in the CLEFT-Q Phase 3 study. The Standard Set includes 9 CLEFT-Q scales, the Nasal Obstruction Symptom Evaluation (NOSE) questionnaire, the Child Oral Health Impact Profile–Oral Symptoms Scale (COHIP-OSS), and the Intelligibility in Context Scale (ICS). Targeting, item-fit statistics, thresholds for item responses, and measurement precision (PSI) were analyzed using Rasch measurement theory.ResultsThe proportion of the sample to score within each instruments range of measurement varied from 69% (ICS) to 92% (CLEFT-Q teeth and COHIP-OSS). Specific problems with individual items within the NOSE and COHIP-OSS questionnaires were noted, such as poor item fit to the Rasch model and disordered thresholds (6 of 10). Reliability measured with PSI was above 0.82 for the ICS and all but one CLEFT-Q scale (speech distress). PSIs were lowest for the COHIP-OSS (0.43) and NOSE questionnaire (0.35).ConclusionThe patient- and parent-reported components within the facial appearance, psychosocial function, and speech domains are valid measures; however, the facial function and oral health domains are not sufficiently covered by the CLEFT-Q eating and drinking, NOSE, and COHIP-OSS, and these questionnaires may not be accurate enough to stratify cleft-related outcomes.  相似文献   
86.
European American (EA) women report greater body dissatisfaction and less dietary control than do African American (AA) women. This study investigated whether ethnic differences in dieting history contributed to differences in body dissatisfaction and dietary control, or to differential changes that may occur during weight loss and regain. Eighty-nine EA and AA women underwent dual-energy X-ray absorptiometry to measure body composition and completed questionnaires to assess body dissatisfaction and dietary control before, after, and one year following, a controlled weight-loss intervention. While EA women reported a more extensive dieting history than AA women, this difference did not contribute to ethnic differences in body dissatisfaction and perceived dietary control. During weight loss, body satisfaction improved more for AA women, and during weight regain, dietary self-efficacy worsened to a greater degree for EA women. Ethnic differences in dieting history did not contribute significantly to these differential changes. Although ethnic differences in body image and dietary control are evident prior to weight loss, and some change differentially by ethnic group during weight loss and regain, differences in dieting history do not contribute significantly to ethnic differences in body image and dietary control.  相似文献   
87.
88.
89.
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