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   5086篇
  免费   391篇
  国内免费   26篇
耳鼻咽喉   92篇
儿科学   194篇
妇产科学   143篇
基础医学   681篇
口腔科学   118篇
临床医学   657篇
内科学   902篇
皮肤病学   128篇
神经病学   629篇
特种医学   129篇
外科学   533篇
综合类   42篇
一般理论   2篇
预防医学   466篇
眼科学   37篇
药学   323篇
中国医学   8篇
肿瘤学   419篇
  2024年   7篇
  2023年   76篇
  2022年   112篇
  2021年   157篇
  2020年   128篇
  2019年   167篇
  2018年   184篇
  2017年   158篇
  2016年   179篇
  2015年   186篇
  2014年   211篇
  2013年   305篇
  2012年   395篇
  2011年   394篇
  2010年   192篇
  2009年   193篇
  2008年   337篇
  2007年   308篇
  2006年   258篇
  2005年   257篇
  2004年   238篇
  2003年   213篇
  2002年   203篇
  2001年   41篇
  2000年   29篇
  1999年   46篇
  1998年   48篇
  1997年   40篇
  1996年   19篇
  1995年   22篇
  1994年   33篇
  1993年   22篇
  1992年   19篇
  1991年   25篇
  1990年   27篇
  1989年   18篇
  1988年   21篇
  1987年   14篇
  1986年   21篇
  1985年   12篇
  1984年   24篇
  1983年   13篇
  1982年   21篇
  1981年   13篇
  1980年   17篇
  1979年   11篇
  1978年   14篇
  1976年   7篇
  1975年   6篇
  1973年   10篇
排序方式: 共有5503条查询结果,搜索用时 15 毫秒
91.
Coronary artery aneurysms are uncommon, usually associated with atherosclerosis and rarely involve all 3 main coronary arteries. Sudden death from documented thrombosis within large coronary aneurysms has been rarely reported. The authors report a case of a previously healthy 36-year-old male who presented with myocardial infarction complicated by sudden cardiac death. The patient was successfully resuscitated, and coronary angiography revealed diffuse, severe aneurysmal disease without evidence of atherosclerosis. A thrombus was visualized in a large aneurysm of the proximal left anterior descending artery, and there was total occlusion of a second diagonal branch, presumably due to thrombus embolization. The patient had no history of Kawasaki disease, and evaluation revealed no inflammatory or autoimmune condition. Optimal treatment and prognosis for patients with nonatherosclerotic coronary aneurysms remains unclear. Our patient was treated medically with chronic warfarin and low-dose aspirin therapy and recovered without complication.  相似文献   
92.
Decreased pituitary-gonadal secretion in men with obstructive sleep apnea   总被引:6,自引:0,他引:6  
Decreased libido is frequently reported in male patients with obstructive sleep apnea (OSA). The decline in morning serum testosterone levels previously reported in these patients was within the normal adult male range and does not explain the frequent association of OSA and sexual dysfunction. We determined serum LH and testosterone levels every 20 min between 2200-0700 h with simultaneous sleep recordings in 10 men with sleep apnea and in 5 normal men free of any breathing disorder in sleep. The mean levels and area under the curve of LH and testosterone were significantly lower in OSA patients compared with controls [LH, 24.9 +/- 10.2 IU/liter.h vs. 43.4 +/- 9.5 (P < 0.005); testosterone, 67.2 +/- 11.5 nmol/liter.h vs. 113.3 +/- 26.8 (P < 0.003)]. Four of 10 patients had hypogonadal morning (0700 h) serum testosterone levels. Analysis of covariance (ANCOVA) revealed that the 2 groups differed significantly in the amount of LH and testosterone secreted at night independent of age or degree of obesity. After partialing out body mass index, there was a significant negative correlation between the amounts of LH and testosterone secreted at night and the respiratory distress index, but not with degree of hypoxia. Our findings suggest that OSA in men is associated with dysfunction of the pituitary-gonadal axis. The relation between LH-testosterone profiles and the severity of OSA suggests that sleep fragmentation and, to a lesser extent, hypoxia in addition to the degree of obesity and aging may be responsible for the central suppression of testosterone in these patients.  相似文献   
93.
94.
Numerous algorithms for the identification and genetic mapping of quantitative trait loci (QTL) have been developed. Methods for confirming QTL maps involve either examination of independent segregating populations or the construction of congenic lines differing only in the QTL of interest. Because these projects require a minimum of several years or thousands of marker assessments in laboratory mice, an alternative, faster congenic method has been pro: posed. In a preliminary study, we tested this method for confirming QTLs identified in crosses between the ILS and ISS selected lines of mice for differential sensitivity to the hypnotic effects of ethanol. Herein, we report the construction of "segregating congenic" strains in which each QTL is made homozygous in a single generation, whereas the remainder of the genetic background is allowed to segregate. Sensitivity to ethanol among the progeny of such mice is consistent with predictions. Phenotypic variation is high, as expected, due to the background segregation, and statistical significance was attained in only 2 of 7 comparisons. Such segregating congenic populations may be a valuable research tool for confirming QTL map positions and for subsequent assessment of individual pathways and mechanisms of action of individual QTLs.  相似文献   
95.
96.
Multislice computed tomography (MSCT) has emerged as the mainstay in patients planned for transcatheter aortic valve implantation (TAVI). Incidental findings (IF) in MSCT are common. However, the exact incidence, clinical relevance and further consequences of IF are unclear and it is controversial whether IF adversely affect patients’ outcome. We analyzed MSCT data of 1050 patients screened for TAVI between January 2011 and December 2014. Median follow-up of patients was 20 months. In total, 3194 IF were identified, which were classified into clinically non-relevant IF (2872, 90%) and clinically relevant IF (322, 10%). In 25% of patients (258/1050) at least one clinically relevant IF was present. Age (80?±?7 vs. 80?±?7 years; p?=?0.198) and EuroSCORE II (3.6% [2.1–5.7] vs. 3.6% [2.1–5.9]; p?=?0.874) was similar between patients with and without a clinically relevant IF. TAVI was performed less frequently in patients with a clinically relevant IF (76% vs. 85%; p?<?0.001), with more patients receiving surgical aortic valve replacement in that group (14% vs. 11%; p?=?0.042), possibly due to the high rate of incidental aneurysms of the ascending aorta (n?=?48). If TAVI was performed mortality did not differ (30-days: 4% vs. 3%; p?=?0.339, 1-year: 11% vs. 14%; p?=?0.226) between patients with and without a clinically relevant IF. Our study is the largest study to analyze prevalence, clinical relevance and therapeutic consequences of IF during screening for TAVI. IF in pre-procedural MSCT are common and clinically relevant in one-quarter of patients. However, these findings had no impact on overall mortality.  相似文献   
97.
The present study aimed to elucidate the profile of coping in patients with obsessive–compulsive disorder (OCD) in order to discern whether the disorder is characterized by an excess of maladaptive coping skills and/or a lack of adaptive coping skills. Sixty individuals with OCD were compared with 110 individuals with depression and 1050 nonclinical controls on the Maladaptive and Adaptive Coping Styles Questionnaire (MAX). Psychopathology was assessed with the Obsessive–Compulsive Inventory-Revised (OCI-R), the Yale-Brown Obsessive–Compulsive Scale (Y-BOCS), and the Patient Health Questionnaire-9 for depression (PHQ-9). Individuals with OCD and depression displayed more maladaptive coping and avoidance as well as less adaptive coping than nonclinical controls. Importantly, adaptive coping was significantly lower in individuals with OCD than in those with depression at a medium effect size, whereas the clinical groups were indistinguishable on maladaptive coping and avoidance. Lack of adaptive coping was strongly correlated with resistance to symptoms and poor insight in OCD (Y-BOCS), even after controlling for depression. Lack of adaptive coping skills may represent a specific pathogenetic factor in OCD. Longitudinal studies need to clarify whether strengthening adaptive skills during childhood and adolescence may help to prevent the progression from subclinical to manifest OCD.  相似文献   
98.

Objective

To identify predictors for employment status after 10 years in a cohort of people with multiple sclerosis (MS), with the aim to increase knowledge concerning factors present at an early stage that are important for working life and work-life balance.

Design

A 10-year longitudinal observational cohort study.

Setting

University hospital.

Participants

A consecutive sample of people with MS (N=154) of working age were included at baseline, of which a total of 116 people participated in the 10-year follow-up; 27 people declined participation and 11 were deceased.

Interventions

Not applicable.

Main Outcome Measures

Baseline data on personal factors and functioning were used as independent variables. Employment status 10 years after baseline, categorized as full-time work, part-time work, and no work, was used as the dependent variable. A generalized ordinal logistic regression was used to analyze the predictive value of the independent variables.

Results

Predictors for full- or part-time work after 10 years were young age (P=.002), low perceived physical impact of MS (P=.02), fatigue (P=.03), full-time work (P=.001), and high frequency of social/lifestyle activities (P=.001) at baseline. Low perceived physical impact of MS (P=.02) at baseline also predicted full-time work after 10 years.

Conclusions

This study underlines the complexity of working life for people with MS, and indicates that it may be valuable to give more attention to the balance between working and private life, both in clinical practice and future research, to achieve a sustainable working life over time.  相似文献   
99.

Context

End-stage kidney disease (ESKD) is characterized by high physical and psychological burden, and therefore, more knowledge about the palliative care provided close to death is needed.

Objectives

To describe symptom prevalence, relief, and management during the last week of life, as well as end-of-life communication, in patients with ESKD.

Methods

This study was based on data from the Swedish Register of Palliative Care. Patients aged 18 or older who died from a chronic kidney disease, with or without dialysis treatment (International Classification of Diseases, Tenth Revision, Sweden; N18.5 or N18.9), during 2011 and 2012 were selected.

Results

About 472 patients were included. Of six predefined symptoms, pain was the most prevalent (69%), followed by respiratory secretion (46%), anxiety (41%), confusion (30%), shortness of breath (22%), and nausea (17%). Of patients with pain and/or anxiety, 32% and 44%, respectively, were only partly relieved or not relieved at all. Of patients with the other symptoms, a majority (55%–84%) were partly relieved or not relieved at all. End-of-life discussions were reported in 41% of patients and 71% of families. A minority died in specialized palliative care: 8% in hospice/inpatient palliative care and 5% in palliative home care. Of all patients, 19% died alone. Bereavement support was offered to 38% of families.

Conclusion

Even if death is expected, most patients dying with ESKD had unmet palliative care needs regarding symptom management, advance care planning, and bereavement support.  相似文献   
100.
Purpose: Problem-based learning (PBL) is an educational method that fosters self-directed study in small groups. The purpose of this study was to describe the Tel Aviv University’s occupational therapy (OT) program and the challenges implementing such program. In addition, the study compared the PBL grades obtained by students who are native Hebrew speakers with those students who are native Arabic speakers; and, assessed the correlation between the grades in the PBL course and the grades in the clinical fieldwork studies.

Method: 166-second year OT undergraduate students participated. All completed three PBL courses and seven weeks of clinical fieldwork studies. Data collection included students’ grades in PBL course (based on PBL evaluation forms) and in clinical fieldwork studies (based on preceptor’s evaluation and a written assignment).

Results: Pearson correlations revealed significant correlations between PBL grades and clinical fieldwork studies grades. T-test analysis between students who are native Hebrew speakers and those who are native Arabic speakers revealed significant differences in PBL grades.

Conclusions: Findings imply partial congruence between students’ grades in the PBL course and their achievements in the fieldwork studies. Findings might suggest that adjustments should be made in order to assist students from minorities (challenged by language requirements) in gaining higher grades in the PBL program.

  • Implications for Rehabilitation
  • Problem-Based Learning (PBL) is an educational method, which fosters independent, self-directed study in small groups.

  • PBL studies have the potential to prepare students for their clinical experience during studies.

  • The PBL program should be adjusted for students from minorities (challenged by language requirements and different cultural backgrounds) in order to assist them in gaining more benefits from the program.

  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