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   46468篇
  免费   3316篇
  国内免费   166篇
耳鼻咽喉   699篇
儿科学   1070篇
妇产科学   699篇
基础医学   5685篇
口腔科学   756篇
临床医学   5219篇
内科学   8934篇
皮肤病学   606篇
神经病学   4123篇
特种医学   1802篇
外国民族医学   2篇
外科学   8078篇
综合类   760篇
现状与发展   1篇
一般理论   32篇
预防医学   3708篇
眼科学   993篇
药学   3504篇
  1篇
中国医学   75篇
肿瘤学   3203篇
  2023年   309篇
  2022年   466篇
  2021年   1218篇
  2020年   641篇
  2019年   1196篇
  2018年   1411篇
  2017年   1015篇
  2016年   1033篇
  2015年   1261篇
  2014年   1853篇
  2013年   2358篇
  2012年   3599篇
  2011年   3846篇
  2010年   2105篇
  2009年   1775篇
  2008年   3097篇
  2007年   3414篇
  2006年   3233篇
  2005年   3089篇
  2004年   2706篇
  2003年   2695篇
  2002年   2397篇
  2001年   340篇
  2000年   219篇
  1999年   342篇
  1998年   484篇
  1997年   332篇
  1996年   288篇
  1995年   290篇
  1994年   242篇
  1993年   202篇
  1992年   155篇
  1991年   136篇
  1990年   137篇
  1989年   146篇
  1988年   135篇
  1987年   122篇
  1986年   102篇
  1985年   129篇
  1984年   146篇
  1983年   128篇
  1982年   162篇
  1981年   138篇
  1980年   155篇
  1979年   75篇
  1978年   87篇
  1977年   60篇
  1976年   51篇
  1975年   52篇
  1974年   40篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
One hundred and sixty-four patients admitted to a psychogeriatric unit were given a combination of four different cognitive tests: the Mini Mental State Examination (MMSE), the Abbreviated Mental Test Score, The Felix Post Unit Score and the compilation of tests recommended by the MRC Alzheimer's Disease Workshop. The tests were compared with respect to their ability to sort accurately cases of dementia and depression, and the effects of age and education on test score and misclassification rate with diagnosis controlled for. The MMSE had a very high misclassification rate for the poorly educated and depressed group. The logistical discriminant functional analysis selected only eight items as the best discriminators between organic/ functional or dementia/depression groups. Only one of these eight was not either a memory or orientation test. The value of simply adding up tests of different aspects of cognitive function in dementia assessment or screening is questioned.  相似文献   
162.
OBJECTIVE: Between 1985 and 1989, the surgical management of neonates with complete transposition (TGA) underwent a transition from atrial to arterial repair. We sought to examine the intermediate outcomes and their associated risk factors in neonates repaired during the era of transition. PATIENTS AND METHODS: Twenty-four institutions entered 829 neonates age less than 15 days in a prospective study. Diagnosis was simple TGA (n=631), TGA with ventricular septal defect (VSD) (n=167), TGA with VSD and pulmonary stenosis (TGA/VSD/PS) (n=30), or TGA with PS (n=1). Repair was by arterial switch (n=516), atrial repair (Senning=175, Mustard=110) or Rastelli (n=28). Time-related events were analysed by parametric hazard function modeling and incremental risk factors for mortality, re-intervention, and late functional assessment were sought. RESULTS: Survival estimates at 6 months, 5, 10, and 15 years are 85, 83, 83, and 81%, respectively. The hazard function for death after repair has two phases: an early rapidly declining phase and an ongoing constant one. Constant phase mortality is less likely after the arterial switch operation and in children with simple TGA. During follow up, at least one re-intervention was required in 167 children (pacemaker, n=35; percutaneous intervention, n=32; baffle re-intervention, n=27; re-operation, n=125). Freedom from re-intervention at 6 months, 5, 10 and 15 years is 93, 82, 77, and 76%, respectively. Of survivors, 87% have been followed up to the last 3 years, including an assessment of functional ability of 562 children (83%). Functional class 15 years after repair is class I in 76%, II in 22%, III in 2%. The proportion in functional class I decreased over time. Psychosocial deficits, especially learning disorders are prevalent. CONCLUSIONS: Survival 15 years after TGA repair is good with most children functioning well, and results are best after an arterial switch operation. There is an ongoing risk of death that is less after the arterial switch operation. With the exception of Rastelli patients, the likelihood of survivors needing re-intervention after 5 years is low. There is need for improved neurodevelopmental outcomes.  相似文献   
163.
164.
Abstract:   Intraspinal clonidine is an effective adjunct to intrathecal/epidural opioid administration. We report a case of neuropathic pain treated with intraspinal analgesics in which depression, insomnia, and night terrors developed in association with intraspinal clonidine.  相似文献   
165.
166.
Regional cerebral blood flow (CBF) was studied with O(15)-water positron emission tomography and anatomic region-of-interest analysis on co-registered magnetic resonance in patients with idiopathic (n = 12) and secondary (n = 5) normal pressure hydrocephalus (NPH). Mean CBF was compared with values obtained from healthy volunteers (n = 12) and with clinical parameters. Mean CBF was significantly decreased in the cerebrum and cerebellum of patients with NPH. The regional analysis demonstrated that CBF was reduced in the basal ganglia and the thalamus but not in white matter regions. The results suggest that the role of the basal ganglia and thalamus in NPH may be more prominent than currently appreciated. The implications for theories regarding the pathogenesis of NPH are discussed.  相似文献   
167.
Stress arising from academic performance affects many college students. Moreover, students account for the majority of participants in cardiovascular reactivity research. The current research comprised three brief experiments investigating different aspects of student samples. In Experiment 1, students' (n = 30) academic fear of failure was found to be negatively correlated with systolic blood pressure reactivity. In Experiment 2, students' (n= 13) blood pressure was found to be significantly elevated 2 weeks before college examinations, compared with postexamination levels. Finally, in Experiment 3, students' (n = 19) examination performance was positively correlated with preexamination cardiovascular reactivity. These findings suggest specific college‐related factors that influence the cardiovascular stress response in students and, therefore, should aid the interpretation of much research conducted in cardiovascular health psychology.  相似文献   
168.
PURPOSE: Although the angle of deviation in patients with congenital esotropia has been shown to increase during the early preoperative period, few data exist regarding this change in other forms of childhood esotropia. The primary objective of this study was to investigate whether the angle of deviation increases with time in patients with acquired nonaccommodative esotropia (ANAET). METHODS: The medical records of all children whose ANAET was diagnosed at East Tennessee State University College of Medicine from August 1, 1995, through October 1, 2001, were retrospectively reviewed. All patients were assessed for any change in the amount of their strabismic angle and associated risk factors. RESULTS: Eighty-two patients with ANAET were identified, and all except 3 underwent more than one examination. Of the 79 children who underwent more than one examination, 26 (32.9%) displayed an angle increase of > or =10 prism diopters (PD) during a median follow-up period of 2.9 months. The ANAET of those patients whose angle increased by > or =10 PD was diagnosed (28.4 months of age vs 45.5 months of age, P =.003), and they underwent surgery (35.9 months of age vs 53.3 months of age, P =.003) at a significantly younger median age than those whose angle increased <10 PD. CONCLUSIONS: The angle of deviation of approximately one third of patients with ANAET in this study increased at least 10 PD in the early preoperative period. This increase occurs more often in younger patients and underscores the importance of performing serial measurements of the deviating angle before surgical intervention is undertaken.  相似文献   
169.
170.
HIPAA Deadline     
Vastag  Brian 《JAMA》2002,288(14):1709
  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