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   2910387篇
  免费   221081篇
  国内免费   5461篇
耳鼻咽喉   39177篇
儿科学   95834篇
妇产科学   80617篇
基础医学   413021篇
口腔科学   86361篇
临床医学   262731篇
内科学   562438篇
皮肤病学   63951篇
神经病学   230955篇
特种医学   112773篇
外国民族医学   699篇
外科学   440256篇
综合类   70574篇
现状与发展   6篇
一般理论   1028篇
预防医学   223075篇
眼科学   68636篇
药学   216823篇
  67篇
中国医学   6401篇
肿瘤学   161506篇
  2018年   30781篇
  2017年   23659篇
  2016年   26157篇
  2015年   29914篇
  2014年   41535篇
  2013年   61982篇
  2012年   84968篇
  2011年   89577篇
  2010年   53030篇
  2009年   49817篇
  2008年   84180篇
  2007年   89239篇
  2006年   90090篇
  2005年   86842篇
  2004年   84666篇
  2003年   80868篇
  2002年   78561篇
  2001年   141380篇
  2000年   145439篇
  1999年   121801篇
  1998年   33155篇
  1997年   29491篇
  1996年   29384篇
  1995年   28364篇
  1994年   26417篇
  1993年   24586篇
  1992年   96487篇
  1991年   93751篇
  1990年   90867篇
  1989年   87651篇
  1988年   80745篇
  1987年   79176篇
  1986年   75254篇
  1985年   72253篇
  1984年   53563篇
  1983年   46024篇
  1982年   26542篇
  1981年   23759篇
  1979年   49623篇
  1978年   34265篇
  1977年   29117篇
  1976年   27345篇
  1975年   28902篇
  1974年   35270篇
  1973年   33877篇
  1972年   31309篇
  1971年   29375篇
  1970年   27146篇
  1969年   25437篇
  1968年   23443篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
ABSTRACT

Language and executive functioning are major impairments in many neurodevelopmental disorders, but little is known about the relations between these constructs, particularly using parent-report. Thus, the current research sought to examine relations between executive function and language in two groups – Down syndrome (DS; n=41; Mage = 11.2) and autism spectrum disorder (ASD; n=91; Mage = 7.7). Results were as follows: in DS, executive function predicted pragmatic, but not structural language after covarying for age, sex, and social functioning; in ASD, executive function predicted both. Findings highlight the interrelatedness of language and executive functioning and may have implications for intervention development.  相似文献   
72.

Background

Various trajectories for lung function and bronchial hyper-reactivity (BHR) from early childhood to adulthood are described, including puberty as a period with excessive lung growth. Bronchiolitis in infancy may be associated with increased risk of developing chronic obstructive pulmonary disease, but the development of respiratory patterns during puberty is poorly characterized for these children. We aimed to study the development and trajectories of lung function and BHR from 11 to 18 years of age in children hospitalized for bronchiolitis in infancy.

Methods

Infants hospitalized for bronchiolitis at the University Hospitals in Stavanger and Bergen, Norway, during 1997-1998, and an age-matched control group, were included in a longitudinal follow-up study and examined at 11 and 18 years of age with spirometry and methacholine provocation test (MPT). The MPT data were managed as dose-response slope (DRS) in the statistical analyses. Changes in lung function and DRS from 11 to 18 years of age were analyzed by generalized estimating equations, including interaction terms.

Results

z-scores for forced vital capacity (FVC), forced expiratory volume in first second (FEV1), FEV1/FVC ratio, and DRS were not different from 11 to 18 years of age in both the post-bronchiolitis and the control group. The trajectories from 11 to 18 years did not differ between the two groups. BHR at age 11 was independently associated with asthma at age 18.

Conclusion

Children hospitalized for bronchiolitis had stable predicted lung function and BHR from 11 to 18 years of age. The lung function trajectories were not different from controls.
  相似文献   
73.
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   
74.
75.
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   
76.
ABSTRACT

Background

Post-stroke dysphagia is characterized by reduced corticolingual excitability and lingual pressure; however, it remains unknown if transcranial magnetic stimulation (TMS) directly facilitates lingual pressure generation.  相似文献   
77.
ABSTRACT

While research on sport-related concussion has increased dramatically over the past decade, research investigating concussion reporting is in its early stages. The purpose of this project was to assess concussion reporting and work with stakeholders to develop and assess strategies to improve reporting. We used a multi-site, repeated measures design with three NCAA Division I football programs, including 223 athlete participants. A modified community-based participatory research (CBPR) approach was used to develop intervention strategies (Fall 2017 season) with stakeholders designed to increase concussion reporting intentions. Preseason and postseason surveys were administered to determine effectiveness. Main outcome measures included concussion knowledge, intervention effectiveness, and reporting intention measures. For all three programs, concussion knowledge was unrelated to reporting intentions. Two of the three programs implemented the intervention strategies and for these programs there was evidence that the interventions were effective. Specifically, athletes from these two programs perceived more support from coaches about reporting (P< 0.05; t= 2.83), received education more frequently (P< 0.05; t= 2.67), and reported being more likely to report concussion symptoms (P< 0.05; t= 2.14). Our study demonstrates that working with stakeholders to develop site-specific strategies to improve concussion reporting is an effective approach to help improve reporting behaviours.  相似文献   
78.
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   
79.

Objectives

Triazole resistance in Aspergillus spp. is emerging and complicates prophylaxis and treatment of invasive aspergillosis (IA) worldwide. New polymerase chain reaction (PCR) tests on broncho-alveolar lavage (BAL) fluid allow for detection of triazole resistance at a genetic level, which has opened up new possibilities for targeted therapy. In the absence of clinical trials, a modelling study delivers estimates of the added value of resistance detection with PCR, and which empiric therapy would be optimal when local resistance rates are known.

Design

A decision-analytic modelling study was performed based on epidemiological data of IA, extended with estimated dynamics of resistance rates and treatment effectiveness. Six clinical strategies were compared that differ in use of PCR diagnostics (used vs not used) and in empiric therapeutic choice in case of unknown triazole susceptibility: voriconazole, liposomal amphotericin B (LAmB) or both. Outcome measures were proportion of correct treatment, survival and serious adverse events.

Results

Implementing aspergillus PCR tests was projected to result in residual treatment-susceptibility mismatches of <5% for a triazole resistance rate up to 20% (using voriconazole). Empiric LAmB outperformed voriconazole at resistance rates >5–20%, depending on PCR use and estimated survival benefits of voriconazole over LAmB. Combination therapy of voriconazole and LAmB performed best at all resistance rates, but the advantage over the other strategies should be weighed against the expected increased number of drug-related serious adverse events. The advantage of combination therapy over LAmB monotherapy became smaller at higher triazole resistance rates.

Conclusions

Introduction of current aspergillus PCR tests on BAL fluid is an effective way to increase the proportion of patients that receive targeted therapy for IA. The results indicate that close monitoring of background resistance rates and adverse drug events are important to attain the potential benefits of LAmB. The choice of strategy ultimately depends on the probability of triazole resistance, the availability of PCR and individual patient characteristics.  相似文献   
80.
Purpose: The purpose of the study is to report the prognostic factors and outcomes of vitrectomy (PPV) with silicone oil tamponade in rhegmatogenous retinal detachment (RRD) secondary to acute retinal necrosis (ARN).

Methods: This retrospective, non-randomized, interventional comparative study included 38 eyes of 38 patients. All cases underwent PPV with silicone oil tamponade. The main outcome measure was improvement of final visual acuity relative to the presenting visual acuity and factors affecting the same Group A included eyes with favorable vision of 20/400 or better and Group B included the others.

Results: Group A included 16 eyes (42.10%), group B included 22 eyes (57.89%). In Group A 2 eyes out of 16 (12.5%) and in Group B 12 eyes out of 22 (54.54%) had RRD at presentation (p = 0.02, 95% CI for the difference 7.88–65.78%). The time interval between first presentation and development of RRD in Group A was 30.94 ± 38.8 days (median 30 days) whereas that in Group B was 10.81 ± 11.73 days (median 8 days) (p = 0.02). The odds of visual improvement post-vitrectomy when RRD occurred later was 8.4 (p = 0.01, 95% CI 1.53–46.1). The usage of systemic steroids (odds 5.2, p = 0.03, 95% CI 1.14–23.54) and oral valacyclovir (odds 4.33, p = 0.04, 95% CI 1.05–17.84) were associated with odds favoring a good visual outcome. Recurrent RRD was noted in 3/16 eyes (18.75%) in Group A and 13/22 eyes (59.09%) in Group B (p = 0.03).

Conclusion: Delayed occurrence of RRD after ARN is a good prognostic factor. Usage of systemic steroids and oral valacylocvir are associated with a favorable visual outcome when started before the onset of RRD.  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