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   20702篇
  免费   6513篇
  国内免费   94篇
耳鼻咽喉   411篇
儿科学   501篇
妇产科学   556篇
基础医学   660篇
口腔科学   1465篇
临床医学   6420篇
内科学   5040篇
皮肤病学   662篇
神经病学   2463篇
特种医学   652篇
外科学   2986篇
综合类   138篇
现状与发展   2篇
一般理论   1篇
预防医学   2744篇
眼科学   446篇
药学   471篇
中国医学   56篇
肿瘤学   1635篇
  2024年   225篇
  2023年   1364篇
  2022年   492篇
  2021年   965篇
  2020年   1315篇
  2019年   693篇
  2018年   1748篇
  2017年   1806篇
  2016年   1765篇
  2015年   1789篇
  2014年   2077篇
  2013年   2070篇
  2012年   994篇
  2011年   958篇
  2010年   1252篇
  2009年   1558篇
  2008年   725篇
  2007年   535篇
  2006年   638篇
  2005年   408篇
  2004年   338篇
  2003年   292篇
  2002年   257篇
  2001年   299篇
  2000年   154篇
  1999年   249篇
  1998年   290篇
  1997年   304篇
  1996年   295篇
  1995年   261篇
  1994年   165篇
  1993年   156篇
  1992年   117篇
  1991年   93篇
  1990年   80篇
  1989年   100篇
  1988年   79篇
  1987年   59篇
  1986年   49篇
  1985年   56篇
  1984年   43篇
  1983年   26篇
  1982年   25篇
  1981年   24篇
  1980年   15篇
  1978年   17篇
  1977年   15篇
  1976年   10篇
  1975年   10篇
  1971年   9篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
121.
The 5-HT1 receptor agonist, sumatriptan, is highly effective in the treatment of migraine. Some patients, however, do not respond or experience recurrence of the headache. In addition, some patients report chest symptoms after sumatriptan. We investigated whether these different responses could be attributed to genetic diversity of the 5-HT1B receptor, which most likely mediates the therapeutic action and the coronary side effects of sumatriptan. Allele frequencies of two polymorphisms in the 5-HT1B receptor gene ( G861C and T-261G ) were investigated in migraine patients with consistently good response to sumatriptan (n=14), with no response (n=12), with recurrence of the headache (n=12), with chest symptoms (n=13), and in patients without chest symptoms (n=27). Allele frequencies (G:0.74; C:0.26 at nt 861 and T:0.39; G:0.61 at nt -261) did not differ between patient groups, indicating that genetic diversity of the 5-HT1B receptor does not seem to be involved in the different clinical responses to sumatriptan.  相似文献   
122.
To learn and teach about HIV/AIDS is to enter complex and senstitive territory that at times may be personally challenging. 5 In the vast literature on HIV infection and nursing two main themes recur: nurses' lack of understanding, negative attitudes and anxieties related to HIV/AIDS and the need for education to change such attitudes and enhance nurses' knowledge and skills.  相似文献   
123.
The health-related behaviours of a random sample (n=92) of Hong Kong nurses were assessed by a questionnaire written either in English or in English and Chinese. Hong Kong nurse reported negligible smoking or a alcohol use, low levels of breast self-examination, cervical screening behaviour and regular exercising, seat belt use and driving within the speed limit. The sample reported high levels of making efforts to avoid foods high in cholesterol, eating foods high in fibre and eating fruit daily. Dental hygiene was reported to be high. Just over half the sample reported sleeping 7–8 hours each night and eating breakfast daily. Most nurse reported maintaining their body weight at a healthy level and eating snacks between meals. The English language version of the questionnaire produced a slightly better response rate than the bilingual questionnaires. The results are discussed with reference to previous studies of females' health-related behaviours in Hong Kong and elsewhere. The implications for Hong Kong nurses' role in health promotion is discussed.  相似文献   
124.
Communications among staff and patients on a stroke rehabilitation ward form the focus of this article, which reports on some aspects of a larger study using a grounded theory approach. Tape-recorded interviews were transcribed and analysed concurrently according to recommendations for the approach. A main theme entitled building a relationship was identified, and this process was found to occur in a context varying from participative at one end of a continuum to hierarchical at the other. Building a relationship was found to be influenced by role, personal qualities and organizational context. Appropriate relationships between role-holders were subject to negotiation, leading to a resulting congruence or incongruence between participants' expectations of each other and their roles. Personal qualities were brought into play in the process, with patients' views of staff and staff views of patients both being influential. Some of these views seemed to parallel what has been described in earlier literature as ‘the sick role’ and the labelling of patients as ‘good’ or ‘bad’. Responses to personal qualities led to nurses ascribing meaning to patients' behaviour in terms of adjustment to their stroke, giving time to them to help them to adjust, and withdrawal and handing over to other staff if this strategy failed. Organizational context also had an influence on building a relationship, with time constraints being identified particularly by nurses, and the need to fit in the most essential aspects of care. Place was also important, in that nurses were confined to the ward as a work location, whereas other therapists and doctors worked in other places and sometimes had the facility to take patients off the ward to concentrate on therapy. The findings are discussed against the background of related literature and the conclusion is drawn that the crucial role of nurses in rehabilitation is not recognized and valued, and that shortages of resources - especially suitably qualified and trained nursing staff- are a negative influence on building the relationships which are vital to successful rehabilitation.  相似文献   
125.
A national study was conducted between 1991 and 1994 to explore and describe the changing role of the nurse teacher following the introduction of Project 2000 pre-registration nursing courses. Multiple methods were used to collect data from a wide variety of respondents (nurse teachers, midwife teachers, clinical nurses, health service managers and higher education lecturers). This paper presents the findings relating to the impact of Project 2000 and the move into higher education on the continuing educational needs of nurse teachers. Views on college strategies for staff development, the changing nature of teachers'academic and professional development needs and the problems of the conflicting demands experienced are reported. The research highlights the need for clinical credibility to be clearly defined in relation to nurse teachers and for educational institutions to place more emphasis on teachers'clinical development if the rhetoric of policy is to become a reality.  相似文献   
126.
127.
BACKGROUND: A cascade of inflammatory reactions characterize acute vascular rejection after heart transplantation. This study was undertaken to test the hypothesis that acute vascular rejection is associated with up-regulation of vitronectin receptor (alphavbeta3), increased expression of tissue factor, and activation of the extracellular matrix metalloproteinase induction system. METHODS: Acute vascular rejection developed in 14 heart transplant recipients within 2 weeks of transplantation, confirmed by immunofluorescence (AVR group). We compared these patients with 10 transplant recipients who had no evidence of acute vascular rejection or peritransplant ischemic injury (control group). We evaluated endomyocardial biopsy specimens for alphavbeta3, tissue factor, and extracellular matrix metalloproteinase inducer (EMMPRIN). RESULTS: Compared with the control group, the AVR group demonstrated evidence of significantly increased expression of alphavbeta3 (1.9-fold, p < 0.001), tissue factor (1.8-fold, p < 0.001), and EMMPRIN (1.5-fold, p < 0.001). All patients in the AVR group received plasmapheresis; 11 of 14 patients had evidence of ischemic necrosis on biopsy specimens, and 3 of 14 patients experienced hemodynamic compromise and graft dysfunction and died within 3 weeks of transplant. Another patient died at 10 months after transplant. CONCLUSIONS: Acute vascular rejection is associated with up-regulation of alphavbeta3, tissue factor, and activation of the matrix metalloproteinase induction system, which may contribute to the lethal morbidity associated with this disease.  相似文献   
128.
129.
INTRODUCTION: Reconstructive septorhinoplasty in complex nasal deformities often requires harvesting a large amount of tissue for grafting. Autogenous septal cartilage has generally been considered the gold standard grafting material. The aim of this paper was to report our experience with the use of costal cartilage grafts in cases with significant structural deformities and insufficient septal cartilage. DESIGN: Retrospective chart review. PATIENTS: Between 1998 and 2006, 37 patients underwent septorhinoplasty using costal cartilage as the primary source for grafting. Twenty-two men and 14 women with a median age of 42 were enrolled in the study. Patient demographics, indications for surgery, and immediate and late complications were reviewed. The follow-up range was 3 to 72 months. CONCLUSIONS: Autogenous costal cartilage graft is a viable option in reconstructive septorhinoplasty. We advocate the use of this graft in septorhinoplasty cases requiring a large volume of tissue and insufficient septal cartilage.  相似文献   
130.
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