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   57582篇
  免费   4041篇
  国内免费   223篇
耳鼻咽喉   683篇
儿科学   1471篇
妇产科学   1079篇
基础医学   7230篇
口腔科学   948篇
临床医学   5576篇
内科学   11809篇
皮肤病学   710篇
神经病学   5541篇
特种医学   1940篇
外国民族医学   4篇
外科学   9767篇
综合类   812篇
现状与发展   1篇
一般理论   69篇
预防医学   5077篇
眼科学   1177篇
药学   3545篇
中国医学   62篇
肿瘤学   4345篇
  2023年   203篇
  2022年   356篇
  2021年   994篇
  2020年   557篇
  2019年   947篇
  2018年   1155篇
  2017年   796篇
  2016年   890篇
  2015年   992篇
  2014年   1642篇
  2013年   2435篇
  2012年   3576篇
  2011年   3881篇
  2010年   2188篇
  2009年   2016篇
  2008年   3504篇
  2007年   3683篇
  2006年   3656篇
  2005年   3749篇
  2004年   3676篇
  2003年   3358篇
  2002年   3290篇
  2001年   473篇
  2000年   357篇
  1999年   565篇
  1998年   748篇
  1997年   635篇
  1996年   571篇
  1995年   538篇
  1994年   482篇
  1993年   439篇
  1992年   358篇
  1991年   364篇
  1990年   297篇
  1989年   302篇
  1988年   285篇
  1987年   272篇
  1986年   253篇
  1985年   302篇
  1984年   468篇
  1983年   398篇
  1982年   522篇
  1981年   508篇
  1980年   495篇
  1979年   250篇
  1978年   291篇
  1977年   284篇
  1976年   221篇
  1975年   218篇
  1974年   235篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
41.
42.
43.
Objective To assess the availability of resources that support the provision of basic neonatal care in eight first‐referral level (district) hospitals in Kenya. Methods We selected two hospitals each from four of Kenya’s eight provinces with the aim of representing the diversity of this part of the health system in Kenya. We created a checklist of 53 indicator items necessary for providing essential basic care to newborns and assessed their availability at each of the eight hospitals by direct observation, and then compared our observations with the opinions of health workers providing care to newborns on recent availability for some items, using a self‐administered structured questionnaire. Results The hospitals surveyed were often unable to maintain a safe hygienic environment for patients and health care workers; staffing was insufficient and sometimes poorly organised to support the provision of care; some key equipment, laboratory tests, drugs and consumables were not available while patient management guidelines were missing in all sites. Conclusion Hospitals appear relatively poorly prepared to fill their proposed role in ensuring newborn survival. More effective interventions are needed to improve them to meet the special needs of this at‐risk group.  相似文献   
44.
45.
46.
This commentary discusses the need for, and the advantages of, a more concise, revised definition of the field of health services research. It argues for a definition that includes not only the topics on which health services research focuses but also the goals of health services research. A number of condensed definitions are provided for consideration.  相似文献   
47.
OBJECTIVE: The authors examined the accuracy of certain neuropsychological tests in the prediction of harm resulting from self-neglect in cognitively impaired seniors who lived alone. METHODS: The study included 130 participants, aged 65 and older, who scored less than 131 on the Dementia Rating Scale. Neuropsychological tests were administered at baseline, resulting in eight predictive scores. Informants and primary care physicians provided information about harm that occurred to the participants during the 18-month prospective follow up. An incident was defined as harmful if it occurred as the result of self-neglect or disorientation and resulted in physical injury or property loss or damage and required emergency interventions. Proportional hazard regression analysis was conducted to examine the predictive relationship between the eight neuropsychological tests and time to incident harm with age, sex, education, the Charlson Comorbidity Index, and the Mini-Mental State Examination included in the model as covariates. RESULTS: Twenty-seven participants experienced harm during the 18-month follow-up period. A proportional hazards model indicated that three neuropsychological tests, which measured recognition memory, executive functioning, and conceptualization, were independent risk factors for harm. CONCLUSIONS: These findings provide insight into why harm occurred in these cognitively impaired elders who lived alone. They also support the ecologic validity of these tests and suggest directions for the development of intervention strategies for harm prevention.  相似文献   
48.
Despite evidence from previous unit recording, microstimulation, lesioning and anatomical studies, the functions of the midbrain periaqueductal gray (PAG) remain unclear. We attempted to clarify the function of the PAG by recording activity of PAG units along with laryngeal and respiratory electromyograms (EMG) during vocalization in awake monkeys. PAG units were classified with respect to vocalization on the basis of their discharge patterns as 'early burst', 'late burst', 'tonic-increase' and 'tonic-off', with the vast majority being of the early- and late-burst type. Early-burst cells were correlated most frequently with inspiratory muscles of the respiratory system and laryngeal abductor muscles. Late-burst cells were most clearly correlated with laryngeal adductor and expiratory respiratory muscles. Data from spike-triggered averaging and parametric correlations indicate that most cells are related to single muscles, but a significant number were related to functionally related groups of two or more muscles. The results suggest that the PAG determines qualitative aspects of vocalization by the multisynaptic action its cells have on laryngeal and respiratory motoneurons.  相似文献   
49.
50.
Limbic kindling was examined in genetically epilepsy-prone (GEPR) and non-epileptic control rats. The early stage of kindling development was accelerated in both groups of GEPR rats compared to controls. Later stages of kindling were accelerated in GEPR-9 but not GEPR-3 rats. These results indicate that GEPR rats have an enhanced susceptibility to limbic kindling and suggest that limbic brain alterations may contribute to acceleration of the early stage kindling development in GEPR rats.  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