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   38070篇
  免费   1371篇
  国内免费   242篇
耳鼻咽喉   575篇
儿科学   1337篇
妇产科学   1165篇
基础医学   2914篇
口腔科学   986篇
临床医学   4322篇
内科学   5787篇
皮肤病学   534篇
神经病学   2524篇
特种医学   2447篇
外科学   8566篇
综合类   1177篇
一般理论   1篇
预防医学   1625篇
眼科学   959篇
药学   1317篇
  5篇
中国医学   202篇
肿瘤学   3240篇
  2024年   36篇
  2023年   1459篇
  2022年   2051篇
  2021年   2222篇
  2020年   2549篇
  2019年   1839篇
  2018年   1588篇
  2017年   1598篇
  2016年   1622篇
  2015年   1749篇
  2014年   2961篇
  2013年   2168篇
  2012年   1620篇
  2011年   1474篇
  2010年   1867篇
  2009年   1657篇
  2008年   1031篇
  2007年   1046篇
  2006年   862篇
  2005年   744篇
  2004年   697篇
  2003年   653篇
  2002年   567篇
  2001年   584篇
  2000年   476篇
  1999年   471篇
  1998年   375篇
  1997年   277篇
  1996年   336篇
  1995年   314篇
  1994年   238篇
  1993年   181篇
  1992年   232篇
  1991年   224篇
  1990年   229篇
  1989年   213篇
  1988年   227篇
  1987年   149篇
  1986年   74篇
  1985年   88篇
  1984年   95篇
  1983年   73篇
  1982年   96篇
  1981年   64篇
  1980年   54篇
  1979年   58篇
  1978年   50篇
  1977年   68篇
  1976年   54篇
  1974年   45篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Background and purposeMimics comprise a third of patients presenting with an acute stroke. There is limited information on their natural history.MethodsWe evaluate long term major cardiovascular events (MACE) in stroke mimics in a prospective database from Qatar.ResultsBetween Feb 2014 and Jan 2019, 481 patients (male: 238; female: 243) mean age 57.5 years (±18.0), with 399 (83%) medical mimics and 82 (17%) functional mimics were evaluated. Imaging revealed previous old stroke in 26.6% and small vessel disease in 5%. MACE occurred in 57 (11.9%) and there were 31 deaths (6.4%) with majority of deaths (5.6%) from cardiovascular causes. MACE was significantly higher in patients with previous stroke, p < 0.0001), coronary artery disease, p = 0.002), diabetic, p = 0.01), and hypertensive on admission, p < 0.0001. MACE were also significantly higher in patients where imaging showed a previous stroke, p = 0.006).ConclusionThe occurrence of MACE during follow-up suggests that patients with existing vascular disease require aggressive management of vascular risk factors.  相似文献   
992.
AimHealthcare providers demonstrate limited retention of knowledge and skills in the months following completion of a resuscitation course. Resuscitation courses are typically taught in a massed format (over 1–2 days) however studies in education psychology have suggested that spacing training may result in improved learning and retention. Our study explored the impact of spaced instruction compared to traditional massed instruction on learner knowledge and pediatric resuscitation skills.MethodsMedical students completed a pediatric resuscitation course in either a spaced or massed format. Four weeks following course completion students completed a knowledge exam and blinded observers used expert-developed checklists to assess student performance of three skills (bag-valve mask ventilation (BVMV), intra-osseous insertion (IOI) and chest compressions (CC)).ResultsForty-five out of 48 students completed the study protocol. Students in both groups had similar scores on the knowledge exam spaced: (37.8 ± 6.1) vs. massed (34.3 ± 7.6)(p < 0.09) and overall global rating scale scores for IOI, BVMV and CC; however students in the spaced group also performed critical procedural elements more frequently than those in the massed training groupConclusionLearner knowledge and performance of procedural skills in pediatric resuscitation taught in a spaced format is at least as good as learning in a massed format. Procedures learned in a spaced format may result in better retention of skills when compared to massed training.  相似文献   
993.
994.
The clinical examination of ruptures of the flexor hallucis longus can be difficult, especially spontaneous defects that arise without a definitive history of trauma. Advanced imaging, in particular, magnetic resonance imaging, can be a useful adjunct to the clinical examination. However, we believe that a simple clinical maneuver can be used to reliably ascertain the presence of a rupture of the flexor hallucis longus.  相似文献   
995.
996.
BackgroundSocial relations can be measured through: a) objective indicators, i.e. the number of social contacts in a given time interval or b) subjective indicators, i.e. feelings of loneliness. Comparing subjective and objective indicators in patients with psychotic and mood disorders may help to understand whether diagnosis-specific interventions should be designed for increasing their social relations. In this study we assessed social contacts outside home, work environments and mental health services, which may be increased by these interventions. We also explored feelings of loneliness which could influence readiness of patients to participate in interventions.Methods100 patients in outpatient mental health care were asked to: a) list their social contacts; b) report their feelings of loneliness on a validated five point Likert scale. Multiple logistic regression models were used to test associations of diagnostic categories with: a) having more than one social contact in the previous week; b) reporting at least moderate feelings of loneliness.ResultsPatients had on average 1.7 (SD = 1.7) social contacts in the previous week (median = 1.0); 77 patients reported at least moderate feelings of loneliness. Patients with psychotic disorders (n = 30) showed a statistical trend towards having just one or no contacts in the week before the assessment (Odds ratio, OR = 2.246, p = .087). Patients with mood disorders were more likely to report at least moderate feelings of loneliness (OR = 2.798; p < .05).ConclusionsPatients with psychotic disorders, compared to those with mood disorders, may be less likely to report feeling lonely although they tend to have less social contacts. Strategies to enhance social relations of people with psychotic disorders may include approaches to increase patients' drive to establish new social contacts and to emotionally support them in this process.  相似文献   
997.
ObjectiveLoneliness is an established risk factor for numerous negative health outcomes. The aims of the present study were to compare the levels of loneliness between patients with psychotic disorders and members of the general population and to identify factors independently associated with loneliness in psychosis.MethodsA total of 207 patients with psychotic disorders recruited between February 2013 and February 2015 from inpatient and day wards and an outpatient clinic of the Institute of Psychiatry and Neurology (IPN) in Warsaw (Poland) were included in this cross-sectional study. They were administered the De Jong Gierveld Loneliness Scale (DJGLS) and a set of instruments assessing three types of explanatory variables: socio-demographic, psychosocial and psychiatric (clinical). The comparison group was a random sample of 20,000 inhabitants of Poland who took part in the Generations and Gender Survey (GGS-PL) conducted in 2011. The two groups were matched for socio-demographic characteristics.ResultsThe patient sample proved to be significantly lonelier than the general population sample. The higher level of loneliness in people with psychotic disorders was most strongly related to psychosocial factors, particularly more severe internalized stigma and lesser social support, followed by worse interpersonal competence and smaller social network. After adjusting for socio-demographic and psychosocial variables, the only clinical variable significantly associated with more intense feelings of loneliness turned out to be the greater number of psychiatric inpatient admissions. The findings did not lend support to the view that socio-demographics play a major role in explaining variation in loneliness in psychosis.ConclusionsPeople with psychotic disorders are predisposed to experiencing elevated levels of loneliness. To counteract the pernicious effects of this on their health and well-being, there is a need for comprehensive therapeutic programs targeting self-stigma, enhancing social support networks and improving social skills.  相似文献   
998.
ObjectivesIt is unclear how physical activity estimates differ when assessed using hip- vs wrist-worn accelerometers. The objective of this study was to compare physical activity assessed by hip- and wrist-worn accelerometers in free-living older women.DesignA cross-sectional study collecting data in free-living environment.MethodsParticipants were from the Women's Health Study, in which an ancillary study is objectively measuring physical activity using accelerometers (ActiGraph GT3X+). We analyzed data from 94 women (mean (SD) age = 71.9 (6.0) years) who wore a hip-worn and wrist-worn accelerometers simultaneously for 7 days.ResultsUsing triaxial data (vector magnitude, VM), total activity volume (counts per day) between the two locations was moderately correlated (Spearman's r = 0.73). Hip and wrist monitors wear locations identically classified 71% individuals who were at the highest 40% or lowest 40% of their respective distributions. Similar patterns and slightly stronger agreements were observed when examining steps instead of VM counts.ConclusionsAccelerometer-assessed physical activity using hip- vs wrist-worn devices was moderately correlated in older, free-living women. However, further research needs to be conducted to examine comparisons of specific activities or physical activity intensity levels.  相似文献   
999.
1000.
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