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   21035篇
  免费   1295篇
  国内免费   31篇
耳鼻咽喉   219篇
儿科学   730篇
妇产科学   609篇
基础医学   2487篇
口腔科学   179篇
临床医学   4003篇
内科学   3605篇
皮肤病学   343篇
神经病学   1803篇
特种医学   534篇
外科学   1803篇
综合类   167篇
一般理论   34篇
预防医学   2769篇
眼科学   206篇
药学   1334篇
  2篇
中国医学   7篇
肿瘤学   1527篇
  2023年   128篇
  2022年   179篇
  2021年   430篇
  2020年   286篇
  2019年   438篇
  2018年   525篇
  2017年   439篇
  2016年   456篇
  2015年   505篇
  2014年   673篇
  2013年   1042篇
  2012年   1518篇
  2011年   1525篇
  2010年   852篇
  2009年   775篇
  2008年   1413篇
  2007年   1537篇
  2006年   1507篇
  2005年   1408篇
  2004年   1378篇
  2003年   1269篇
  2002年   1184篇
  2001年   176篇
  2000年   109篇
  1999年   174篇
  1998年   244篇
  1997年   199篇
  1996年   199篇
  1995年   176篇
  1994年   171篇
  1993年   129篇
  1992年   114篇
  1991年   104篇
  1990年   105篇
  1989年   77篇
  1988年   85篇
  1987年   72篇
  1986年   72篇
  1985年   73篇
  1984年   64篇
  1983年   44篇
  1982年   71篇
  1981年   78篇
  1980年   63篇
  1979年   31篇
  1978年   39篇
  1977年   31篇
  1976年   23篇
  1974年   20篇
  1973年   18篇
排序方式: 共有10000条查询结果,搜索用时 23 毫秒
51.
Book Reviews : RESPIRATORY DISORDERS Susan F. Wilson & June M. Thompson Book Reviews : PROCEEDINGS FROM THE FIRST COLLOQUIUM ON PREVENTING SECONDARY DISABILITIES AMONG PEOPLE WITH SPINAL CORD INJURY Philip L. Graitcer & Frederick M. Maynard (Eds.) Book Reviews : KRUSEN'S HANDBOOK OF PHYSICAL MEDICINE AND REHABILITATION (4th ed.) Frederick J. Kottke & Justus F. Lehmann (Eds.) Book Reviews : PSYCHOLOGICAL MANAGEMENT OF TRAUMATIC BRAIN INJURIES IN CHILDREN AND ADOLESCENTS Ellen Lehr Book Reviews : TRAUMA, TRANSFORMATION, AND HEALING John P. Wilson, Brunner/Mazel Book Reviews : REHABILITATION AND DISABILITY: PSYCHOSOCIAL CASE STUDIES E. Davis Martin, Jr., & Gerald L. Gandy, Charles C. Thomas  相似文献   
52.
Survival of patients with surgically treated malignancy may be adversely affected by blood transfusion. Immune suppression due to transfusion has been implicated but remains unproven. We conducted a study of 240 patients with squamous cell carcinoma of the larynx undergoing laryngectomy to assess the effect of per-operative blood transfusion on survival.  相似文献   
53.
The mapping of 5-HT2 receptors in the brain using functional imaging techniques has been limited by a relative lack of selective radioligands. Iodine-123 labelled 4-amino-N-[1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl]-5-iodo-2-methoxybenzamide (123I-5-I-R91150 or123I-R93274) is a new ligand for single-photon emission tomography (SPET), with high affinity and selectivity for 5-HT2A receptors. This study reports on preliminary123I-5-I-R91150 SPET, wholebody and blood distribution findings in five healthy human volunteers. Maximal brain uptake was approximately 2% of total body counts at 180 min post injection (p.i.). Dynamic SPET sequences were acquired with the brain-dedicated, single-slice multi-detector system SEM-810 over 200 min p.i. Early peak uptake (at 5 min p.i.) was seen in the cerebellum, a region free from 5HT2A receptors. In contrast, radioligand binding in the frontal cortex increased steadily over time, up to a peak at approximately 100–120 min p.i. Frontal cortex-cerebellum activity ratios reached values of 1.4, and remained stable from approximately 100 min p.i. onwards. Multi-slice SPET sequences showed a pattern of regional variation of binding compatible with the autoradiographic data on the distribution of 5-HT2A receptors in (cerebral cortex>striatum>cerebellum). These findings suggest that123I-5-I-R91150 may be used for the imaging of 5-HT2A receptors in the living human brain with SPET.  相似文献   
54.
‘Wandering’ is one of the most troublesome of behavioural problems in dementia. The term ‘wandering’ covers many different types of behaviour. We examined the hypothesis that the different types of wandering behaviour seen in dementia from a scale using data collected on 83 elderly subjects suffering from either Alzheimer's disease or multiinfarct dementia. We reject the scaling hypothesis. Our data suggest that there are three main categories of wandering behaviour, and that one of these categories is usefully divided into four subcategories.  相似文献   
55.
For 3 months in 1969 a family in the United States that included a pregnant mother consumed pork containing methylmercury. Children, aged 20, 13, and 8 years and a neonate, developed severe neurological signs. Twenty-two years later, the 2 oldest had cortical blindness or constricted visual fields, diminished hand proprioception, choreoathetosis, and atentional deficits. Magnetic resonance images showed tissue loss in the calcarine and parietal cortices and cerebellar folia. The youngest had quadriplegia, blindness, and severe mental retradation until their deaths. The brain of the 8-year-old who died at age 30 showed cortical atrophy, neuronal loss, and gliosis, most pronounced in the paracentral and parietooccipital regions. The total mercury level in formalin-fixed, left occipital cortex was 1,974 ng/gm as measured by atomic absorption. Regional brain mercury levels correlated with extent of brain damage. A control patient had 38.5 ng of mercury/gm in the occipital cortex. Systemic organs in the patient and a control subject had comparable mercury levels. In mercury-intoxicated rats, we found that only 5 to 10% of total brain mercury was lost by formalin fixation. Brain inorganic mercury in the patient ranged from 82 to 100%. Since inorganic mercury crosses the blood-brain barrier poorly, biotransformation of methyl to inorganic mercury may have occurred after methylmercury crossed the blood-brain barrier, accounting for its persistence in brain and causing part of the brain damage.  相似文献   
56.
On inpatient psychiatric units, nurses control the tone, pace, and activity level of the environment. But under the influence of factors such as high patient acuity and negative group contagion, a milieu can become unacceptably loud and chaotic. A volatile milieu is a potentially dangerous environment because patients' anxiety and agitation can quickly lead to acting out and aggression. This article focuses on how nurses can regain control of a milieu spiralling into chaos by tightening the structure of the routine, anticipating potential problems, and maintaining a confident calm manner. The charge nurse orchestrates the staff group's response to escalation through detailed planning, decisive interventions, and strategic use of every available resource.  相似文献   
57.
58.
59.
The present study sought to investigate the moderating function that social problem-solving effectiveness serves in relation to negative stressful life events and depressive symptomatology. It was also hypothesized that knowledge of problem solving would improve upon the prediction of level of depressive symptoms beyond the assessment of stressful events. Results involving 462 undergraduate students provide support for both predictions. Specifically, findings from a multiple regression analysis indicated that (1) differences in reported depressive mood between subjects under high and low stress levels were minimal for individuals characterized as effective problem-solvers, relative to those persons with problem-solving scores reflective of ineffective problem solving; and (2) assessment of problem-solving scores and their interaction with stress level provided for an additional three times the amount of explained variance in predicting depression scores beyond life stress scores. Additionally, a cross-validation of the regression analysis was conducted and found to result in a minimal amount of shrinkage that could be due to samplespecific characteristics.We would like to extend our appreciation to two anonymous reviewers for their helpful comments on an earlier draft of this article. The study was supported in part by a grant funded by Fairleigh Dickinson University to the first author.  相似文献   
60.
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