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   2692188篇
  免费   205339篇
  国内免费   8488篇
耳鼻咽喉   34933篇
儿科学   88245篇
妇产科学   72971篇
基础医学   375482篇
口腔科学   76291篇
临床医学   243676篇
内科学   535948篇
皮肤病学   62585篇
神经病学   214563篇
特种医学   105021篇
外国民族医学   504篇
外科学   412963篇
综合类   63787篇
现状与发展   6篇
一般理论   902篇
预防医学   208086篇
眼科学   61526篇
药学   193809篇
  58篇
中国医学   5925篇
肿瘤学   148734篇
  2018年   29342篇
  2017年   22505篇
  2016年   25637篇
  2015年   29039篇
  2014年   40488篇
  2013年   60136篇
  2012年   78937篇
  2011年   83986篇
  2010年   50943篇
  2009年   48354篇
  2008年   78034篇
  2007年   83142篇
  2006年   84441篇
  2005年   81115篇
  2004年   77999篇
  2003年   74852篇
  2002年   71720篇
  2001年   134576篇
  2000年   138173篇
  1999年   114634篇
  1998年   32197篇
  1997年   28375篇
  1996年   29123篇
  1995年   28634篇
  1994年   26502篇
  1993年   24677篇
  1992年   90635篇
  1991年   87874篇
  1990年   84748篇
  1989年   81233篇
  1988年   74629篇
  1987年   73241篇
  1986年   69019篇
  1985年   65958篇
  1984年   49466篇
  1983年   41780篇
  1982年   24748篇
  1981年   22205篇
  1980年   20562篇
  1979年   44014篇
  1978年   31157篇
  1977年   26537篇
  1976年   24571篇
  1975年   25747篇
  1974年   30671篇
  1973年   29548篇
  1972年   27447篇
  1971年   25264篇
  1970年   23321篇
  1969年   21884篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Abstract

Objective

Demands for out-of-hours primary care (OOH-PC) services are increasing. Many citizens call because of non-urgent health problems. Nevertheless, the patients’ motives for requesting medical help outside office hours remains an understudied area. This study aimed to examine motives for calling OOH-PC services in various age groups.  相似文献   
62.
63.
IntroductionShared decision-making incorporates patients’ values and preferences to achieve high-quality decisions. The objective of this study was to develop an acceptable patient decision aid to facilitate shared decision-making for the management of small renal masses (SRMs).MethodsThe International Patient Decision Aids Standards were used to guide an evidence-based development process. Management options included active surveillance, thermal ablation, partial nephrectomy, and radical nephrectomy. A literature review was performed to provide incidence rates for outcomes of each option. Once a prototype was complete, alpha-testing was performed using a 10-question survey to assess acceptability with patients, patient advocates, urologists, and methodological experts. The primary outcome was acceptability of the decision aid.ResultsA novel patient decision aid was created to facilitate shared decision-making for the management of SRMs. Acceptability testing was performed with 20 patients, 10 urologists, two patient advocates, and one methodological expert. Responders indicated the decision aid was appropriate in length (82%, 27/33), well-balanced (82%, 27/33), and had language that was easy to follow (94%, 31/33). All patient responders felt the decision aid would have been helpful during their consultation and would recommend the decision aid for future patients (100%, 20/20). Most urologists reported they intend to use the decision aid (90%, 9/10).ConclusionsA novel patient decision aid was created to facilitate shared decision-making for management of SRMs. This clinical tool was acceptable with patients, patient advocates, and urologists and is freely available at: https://decisionaid.ohri.ca/decaids.html.  相似文献   
64.
Abstract

Public health crises, including pandemics, are associated with significant health risk and concomitant stress, fear, decreased sense of control, and uncertainty. Deleterious impact on both physical and mental health can result, including for healthcare professionals and health professions trainees. Changes in governmental policies and hospital protocols for healthcare professionals as well as disruption of educational formats and requirements for trainees can ensue. Difficult anxiety-provoking realities of public health crises including pandemics which involve caring for many seriously ill patients, moral distress including difficult care decisions, personal health risk, and/or potential risk to one’s family can take a dire toll on the mental health of healthcare professionals at all stages of the professional lifecycle. Educational disruptions can create significant anxiety for trainees about completing requirements and achieving competencies. Within this, coping skills may be challenged and strengths may be elucidated as well. Such crises create an imperative for medical educators to support trainees’ wellbeing through adaptive flexibility for curriculum innovation and culturally sensitive resilience and wellbeing interventions. Strategies (‘tips’) to optimize resilience and wellbeing with an integrative resilience approach of individual, learning environment, and organization/systems factors are presented.  相似文献   
65.
Objective: Shoulder pain after spinal cord injury (SCI) is attributed to increased mobility demands on the arms and negatively impacts independence and quality of life. Repetitive superior and posterior shoulder joint forces produced during traditional wheelchair (WC) locomotion can result in subacromial impingement if unopposed, as with muscular fatigue or weakness. ROWHEELS® (RW), geared rear wheels that produce forward WC movement with backward rim pulling, could alter these forces.

Design: Cross sectional.

Setting: Research laboratory at a rehabilitation hospital.

Participants: Ten manual WC users with paraplegia.

Outcome measures: Propulsion characteristics and right upper extremity/trunk kinematics and shoulder muscle activity were collected during ergometer propulsion: (1) self-selected free speed reverse propulsion with RW, (2) matched-speed reverse (rSW), and (3) forward propulsion (fSW) with instrumented Smartwheels (SW). Inverse dynamics using right-side SW rim kinetics and kinematics compared shoulder kinetics during rSW and fSW.

Results: Free propulsion velocity, cycle distance and cadence were similar during RW, rSW and fSW. Overall shoulder motion was similar except that peak shoulder extension was significantly reduced in both RW and rSW versus fSW. Anteriorly and inferiorly directed SW rim forces were decreased during rSW versus fSW propulsion, but posteriorly and superiorly directed rim forces were significantly greater. Superior and posterior shoulder joint forces and flexor, adductor, and external rotation moments were significantly less during rSW, without a significant difference in net shoulder forces and moments. Traditional propulsive-phase muscle activity was significantly reduced and recovery-phase muscle activity was increased during reverse propulsion.

Conclusion: These results suggest that reverse propulsion may redirect shoulder demands and prevent subacromial impingement, thereby preventing injury and preserving independent mobility for individuals with paraplegia.  相似文献   
66.
67.
During the ongoing public health crisis, many agencies are reporting COVID-19 health outcome information based on the overall population. This practice can lead to misleading results and underestimation of high risk areas. To gain a better understanding of spatial and temporal distribution of COVID-19 deaths; the long term care facility (LTCF) and household population (HP) deaths must be used. This approach allows us to better discern high risk areas and provides policy makers with reliable information for community engagement and mitigation strategies. By focusing on high-risk LTCFs and residential areas, protective measures can be implemented to minimize COVID-19 spread and subsequent mortality.  These areas should be a high priority target when COVID-19 vaccines become available

During the current public health crisis, many agencies and media outlets are reporting COVID-19 health outcome information based on the overall population of Cook County. As we have demonstrated, overall COVID-19 case counts and mortality can be misleading (details in >Story Map 1). Moreover, they offer little guidance for delivering public health interventions to high risk populations, a critical need during this second and potentially more devastating wave of the pandemic. The University of Illinois Chicago School of Public Health’s Public Health Geographic Information System Program (UIC-SPH-PHGIS) and Purdue research team has been examining spatial and temporal patterns of COVID-19 mortality with a focus on the significant loss of life from COVID-19 among Long-Term Care Facility (LTCF) residents in contrast to mortality in the community among residents of private households (non-LTCF; referred to as household population, HP). The goals of the study are:
  • Improve the accuracy of commonly quoted COVID-19 mortality indicators;
  • Gain a better understanding of spatial and temporal distribution of COVID-19 deaths;
  • Examine the role of race, ethnicity, and socioeconomic status in COVID-19 mortality;
  • Identify population and organizational parameters that can inform strategies for public health interventions.
Prioritizing the allocation of resources based on reliable information is a prerequisite of a successful mitigation strategy and immunization plan. Findings from our research have significant practical implications. The state and federal government face a series of policy decisions both due to the recent surge in positive cases and, when the time comes, the need to rationalize distribution of vaccines to high priority groups beyond healthcare workers and nursing home residents in critical areas. The research team seeks to modify prevailing practices in order to derive reliable information that guides policy decisions. At this stage of the study, we identified high-risk LTCFs and residential areas (HP) of Cook County from readily available, real-time mortality data.  相似文献   
68.
ABSTRACT

Purpose: To evaluate immunoblot (IB) and polymerase chain reaction (PCR) to diagnose ocular- and neurosyphilis.

Methods: Prospective cross-sectional study. Aqueous humor (AH) and cerebrospinal fluid (CSF) samples were tested for treponemal DNA or antibodies to treponemal antigens.

Results: Thirteen of 106 cases had positive syphilis serology of which 69.2% were HIV+ (median CD4+ = 181 cells/µL). Four cases met CDC criteria for neurosyphilis (3 confirmed, 1 probable) and 2 additional cases required neurosyphilis treatment according to UpToDate algorithms. All AH and CSF samples tested PCR negative. Five cases were CSF IB+ and 3 cases AH IB+. Using our classification, eight patients had confirmed neurosyphilis, one had probable neurosyphilis, three had confirmed ocular syphilis and nine had probable ocular syphilis.

Conclusion: Our findings suggest that IB of AH and CSF provides additional evidence to diagnose ocular and neurosyphilis and allows us to classify them as probable or confirmed.  相似文献   
69.
Abstract

Objectives: Overlapping decreases in extrastriatal dopamine D2/D3-receptor availability and glucose metabolism have been reported in subjects with schizophrenia. It remains unknown whether these findings are physiologically related or coincidental.

Methods: To ascertain this, we used two consecutive 18F-fluorodeoxyglucose and 18F-fallypride positron emission tomography scans in 19 healthy and 25 unmedicated schizophrenia subjects. Matrices of correlations between 18F-fluorodeoxyglucose uptake and 18F-fallypride binding in voxels at the same xyz location and AFNI-generated regions of interest were evaluated in both diagnostic groups.

Results: 18F-fluorodeoxyglucose uptake and 18F-fallypride binding potential were predominantly positively correlated across the striatal and extrastriatal grey matter in both healthy and schizophrenia subjects. In comparison to healthy subjects, significantly weaker correlations in subjects with schizophrenia were confirmed in the right cingulate gyrus and thalamus, including the mediodorsal, lateral dorsal, anterior, and midline nuclei. Schizophrenia subjects showed decreased D2/D3-receptor availability in the hypothalamus, mamillary bodies, thalamus and several thalamic nuclei, and increased glucose uptake in three lobules of the cerebellar vermis.

Conclusions: Dopaminergic system may be involved in modulation of grey matter metabolism and neurometabolic coupling in both healthy human brain and psychopathology. Hyperdopaminergic state in untreated schizophrenia may at least partly account for the corresponding decreases in grey matter metabolism.  相似文献   
70.
Abstract

In light of a growing body of evidence demonstrating pervasive health disparities, medical schools are increasingly incorporating educational programs on social medicine in undergraduate and graduate medical curricula. In 2015, we significantly restructured the cultural competency instruction for medical students at our institution, focusing on achieving greater health equity through caring for vulnerable populations and acknowledging and addressing bias and stereotyping. In order to facilitate educational sustainability while students were immersed in clinical care, a key element of our approach included extending teaching into the clerkship year. The resulting longitudinal thread, Health Equity and Social Justice, empowers future physicians with the knowledge and skills to work towards greater health equity. This article discusses the lessons learned in the implementation of this novel educational program. Our approach can serve as a model for other institutions considering similar instructional reform.  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