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   9232篇
  免费   2459篇
  国内免费   128篇
耳鼻咽喉   370篇
儿科学   193篇
妇产科学   253篇
基础医学   180篇
口腔科学   152篇
临床医学   2909篇
内科学   1731篇
皮肤病学   307篇
神经病学   741篇
特种医学   333篇
外科学   1326篇
综合类   362篇
现状与发展   2篇
预防医学   1748篇
眼科学   100篇
药学   199篇
  1篇
中国医学   100篇
肿瘤学   812篇
  2024年   80篇
  2023年   411篇
  2022年   116篇
  2021年   259篇
  2020年   487篇
  2019年   171篇
  2018年   561篇
  2017年   603篇
  2016年   624篇
  2015年   712篇
  2014年   711篇
  2013年   1048篇
  2012年   387篇
  2011年   338篇
  2010年   515篇
  2009年   629篇
  2008年   305篇
  2007年   244篇
  2006年   277篇
  2005年   192篇
  2004年   149篇
  2003年   114篇
  2002年   105篇
  2001年   191篇
  2000年   121篇
  1999年   154篇
  1998年   270篇
  1997年   289篇
  1996年   309篇
  1995年   244篇
  1994年   174篇
  1993年   121篇
  1992年   98篇
  1991年   94篇
  1990年   78篇
  1989年   97篇
  1988年   75篇
  1987年   60篇
  1986年   52篇
  1985年   59篇
  1984年   52篇
  1983年   45篇
  1982年   32篇
  1981年   44篇
  1980年   19篇
  1979年   12篇
  1978年   14篇
  1977年   15篇
  1976年   14篇
  1975年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Repair and regeneration are mutually exclusive responses to injury. Previous studies have shown that wound fluids promote proliferation, but not differentiation, of myoblasts in vitro. This study explored the ability of the repair environment within polyvinyl alcohol sponges to support cellular events of skeletal muscle regeneration in vivo. Neonatal rat L8 myoblasts were modified to express beta-galactosidase then inoculated into plain sponges or sponges containing minced muscle. Labeled myoblasts were found in myotubes within minced muscle. In contrast, myoblasts inoculated into sponges lacking muscle remained mononucleate. Occurrence of labeled myoblasts within myotubes, which required fusion, represents differentiation of inoculated myoblasts to participate in regeneration. Failure of myoblasts to form myotubes in sponges lacking muscle suggests that this wound repair environment cannot support morphologic differentiation of myoblasts. Although this repair environment can support the survival of myoblasts, it did not support myogenesis, an event necessary to complete skeletal muscle regeneration. Data from this study reinforce earlier studies in vitro and suggest that the properties attributed to wound fluids are inherent in the wound environment. Whether the inability of this environment to support myogenesis is the consequence of the absence of essential factors or the presence of inhibitors remains to be determined.  相似文献   
32.
This article summarizes what is known about the effects of cocaine, opiates, marijuana, and alcohol on neonatal and postnatal growth and development. The development of a child affected by prenatal exposure to drugs and alcohol is best understood through a multifactorial model consisting of interrelated prenatal and postnatal factors. The article also describes the prenatal effects of drugs and alcohol on the newborn, especially on central nervous system functioning, which is seen as creating a biologic vulnerability that renders a child more vulnerable to the effects of poor caretaking.  相似文献   
33.
This paper presents the results of a qualitative study conducted by midwife researchers into women's experience of new motherhood. Data were collected using focus groups involving 55 first-time mothers and analysed using grounded theory method. The analysis produced six categories: 'realizing', 'unready', 'drained', 'aloneness', 'loss' and 'working it out'. The core category, 'becoming a mother', integrates all other categories and encapsulates the process of change experienced by women. Also explained are factors mediating the often distressing experience of becoming a mother. The analysis provides a conceptualization of early motherhood enabling the development of strategies for midwives, nurses and others helping women negotiate this challenge.  相似文献   
34.
The history of antenatal education throws light on why contemporary class attenders represent only a particular section of the childbearing population. Since Victorian times, the non-availability of the women's network to middle class women has forced them to seek knowledge of their own bodies, confidence in their childbearing capacities and the support of other women through formal educational opportunities. Research suggests that antenatal classes often fail to provide women with a realistic account of birth and parenting to replace the lived experience of earlier decades and may not be facilitated in such a way as to create the support groups which class attenders critically need. Teaching approaches often promote dependency amongst clients rather than nurturing the decision-making skills required by a consumer-driven maternity service.  相似文献   
35.
The results of a survey of children attending an Accident and Emergency (A & E) Department following ingestion of alcohol are reported. Data were analysed to indicate age and sex of children, date and time of attendance, method of transport to hospital, whether accompanied to hospital and if so by whom, and whether admitted or discharged. Trends in children's consumption of alcohol, as observed by the author, are discussed.  相似文献   
36.
This paper reports the psychometric testing of the Worthing Chemotherapy Questionnaire(WCQ). The WCQ is a patient self-report instrument to document side-effects of chemotherapy. Literature review of relevant studies shows that psychometric testing of similar instruments is rarely rigorous. Content validity for the WCQ was established in five ways: literature review, Delphi review among oncology staff, pre-pilot unstructured interviews, pilot study and amendment of the instrument and items for spontaneous reporting of problems on the questionnaire. A three-stage approach to construct validity was used. The hypothesis adopted was that as certain cytotoxic agents cause stomatitis, incidence and severity of stomatitis will decrease following cessation of treatment. Stage 1: factor analysis confirmed the presence of a sole factor, with an eigenvalue of 5.3, for mouth problems which explained 65.5% of the variance. Stage 2: the hypothesis was confirmed using research findings. Stage 3: the Wilcoxon test showed highly significant results for during and post chemotherapy stomatitis scores. Reliability of the questionnaire was assessed using the test-retest method. Weighted Kappa was chosen as the test statistic. A median value of wK=0.87 was obtained. The results indicate that the WCQ is a reliable and valid instrument.  相似文献   
37.
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   
38.
The objective of our study was to examine (1) whether isometric muscle strength contributes to the explanation of the physical functional disability of a rheumatoid arthritis (RA) patient population after accounting for other disease parameters and demographic variables and (2) whether change in isometric muscle strength is an indicator of change in physical functional disability. Sixty-five consecutive patients fulfilling the American Rheumatism Association 1987 revised criteria for RA were included in the study. Isometric muscle strength was measured with a validated Muscle Strength Index (MSI) calculated as the mean score of standardized isometric extension and flexion strength of the knee and elbow joints. Physical functional disability was measured with the physical dimension of the Health Assessment Questionnaire (HAQ). For 56 patients, we could obtain 1 yr follow-up data. Cross-sectionally, there was a significant correlation (r = - 0.51, P < 0.01) between the MSI and the HAQ. Muscle strength remained a significant determinant of the HAQ in multivariate analysis accounting for disease and demographic variables. Longitudinally, change in MSI explained additional variance of change in HAQ after accounting for change in pain, the most important correlate of change in HAQ.   相似文献   
39.
Postoperative radiotherapy for locally advanced colon cancer   总被引:1,自引:0,他引:1  
Background: The role of adjuvant postoperative radiotherapy for locally advanced colon cancer is not well documented. Methods: Seventy-eight patients who underwent a complete resection of B2-C colon cancer received postoperative radiotherapy. Twenty-eight patients received ⩽45 Gy; 50 patients received 50–55 Gy. Twenty-seven patients received adjuvant fluorouracil-based chemotherapy. All patients were followed for a minimum of 3 years; no patients were lost to follow-up. Results: The overall local control rate was 88%. The 5-year actuarial rate of local control was 96% after 50–55 Gy postoperative radiotherapy compared with 76% after <50 Gy (p=0.0095). Multivariate analysis of local control showed that only radiotherapy dose significantly influenced this end point. Cause-specific survival rates at 5 years were B2, 67%; B3, 90%; C1, 100%; C2, 61%; C3, 36%; and overall, 63%. Multivariate analysis of cause-specific survival showed that only stage significantly influenced this end point. Bowel obstruction caused by adhesions developed in three patients and required a laparotomy; radiation-induced sarcoma developed in one additional patient. Conclusions: Postoperative radiotherapy appears to reduce the risk of local recurrence in patients with locally advanced colon cancer. The optimal dose is probably 50–55 Gy at 1.8 Gy per fraction. Postoperative radiotherapy may improve cause-specific survival for patients with stages B3 and C2 cancers.  相似文献   
40.
The widespread use and misuse of alcohol, drug and other psychoactive substances are major health and social concerns that affect the lives of many The social and health sequelae of psychoactive drugs and alcohol are preventable and manageable with minimal interventions Nurses and other health workers can effectively respond to substance misuse problems and their existing generic skills can be easily adapted in working with substance misusers This paper considers some of the issues such as the extent of the problem, attitudinal considerations, response to substance misusers and a brief outline of the role of the nurse The urgent need for education and training in substance misuse and addictive behaviour for nurse practitioners is also addressed  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