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   23601篇
  免费   1272篇
  国内免费   172篇
耳鼻咽喉   326篇
儿科学   458篇
妇产科学   550篇
基础医学   2830篇
口腔科学   754篇
临床医学   1925篇
内科学   6390篇
皮肤病学   408篇
神经病学   2309篇
特种医学   743篇
外科学   3455篇
综合类   84篇
一般理论   9篇
预防医学   1095篇
眼科学   317篇
药学   1551篇
  1篇
中国医学   42篇
肿瘤学   1798篇
  2024年   19篇
  2023年   159篇
  2022年   345篇
  2021年   667篇
  2020年   384篇
  2019年   554篇
  2018年   640篇
  2017年   478篇
  2016年   569篇
  2015年   606篇
  2014年   924篇
  2013年   1172篇
  2012年   1821篇
  2011年   1805篇
  2010年   1067篇
  2009年   948篇
  2008年   1641篇
  2007年   1571篇
  2006年   1483篇
  2005年   1485篇
  2004年   1385篇
  2003年   1266篇
  2002年   1159篇
  2001年   177篇
  2000年   178篇
  1999年   204篇
  1998年   196篇
  1997年   187篇
  1996年   185篇
  1995年   170篇
  1994年   137篇
  1993年   126篇
  1992年   116篇
  1991年   76篇
  1990年   92篇
  1989年   82篇
  1988年   79篇
  1987年   85篇
  1986年   68篇
  1985年   72篇
  1984年   78篇
  1983年   76篇
  1982年   67篇
  1981年   60篇
  1980年   55篇
  1979年   31篇
  1978年   40篇
  1977年   27篇
  1976年   21篇
  1975年   17篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Long head biceps (LHB) tendon pathologies are becoming increasingly recognized causes of shoulder pain in the published literature. Instability of LHB presenting as dislocation or subluxation has been recently recognized as a possible cause of disabling pain or discomfort of the shoulder. A clinical diagnosis of LHB instability is very difficult and often confounding because of association with other shoulder pathologies. However, an early diagnosis of LHB instability is important in order to prevent the evolution of lesions of the biceps pulley until an internal anterosuperior impingement of the shoulder (ASI) and subscapular tear occur. The advent of arthroscopy contributed to enhance understandings. The goal of this article is to describe an arthroscopic sign, the chondral print on the humeral head, associated with a LHB instability, that when present can be very useful to help the surgeon to make the diagnosis of unstable LHB tendon.  相似文献   
982.
To assess the accuracy and efficacy of intravascular ultrasound guidance obtained by an intracardiac ultrasound probe during complex aortic endografting. Between November 1999 and July 2002, 19 patients (5 female, 14 male; mean age 73.5 ± 2.1 years) underwent endovascular repair of thoracic (n = 10), complex abdominal (n = 6) and concomitant thoraco-abdominal (n = 3) aortic aneurysm. The most suitable size and configuration of the stent-graft were chosen on the basis of preoperative computed tomographic angiography (CTA) or magnetic resonance angiography (MRA). Intraoperative intravascular ultrasound imaging was obtained using a 9 Fr, 9 MHz intracardiac echocardiography (ICE) probe, 110 cm in length, inserted through a 10 Fr precurved long sheath. The endografts were deployed as planned by CTA or MRA. Before stent-graft deployment, the ICE probe allowed us to view the posterior aortic arch and descending thoraco-abdominal aorta without position-related artifacts, and to identify both sites of stent-graft positioning. After stent-graft deployment, the ICE probe allowed us to detect the need for additional modular components to internally reline the aorta in 11 patients, and to discover 2 incomplete graft expansions subsequently treated with adjunctive balloon angioplasty. In 1 patient, the ICE probe supported the decision that the patient was ineligible for the endovascular exclusion procedure. The ICE probe provides accurate information on the anatomy of the posterior aortic arch and thoracic and abdominal aortic aneurysms and a rapid identification of attachment sites and stent-graft pathology, allowing refinement and improvement of the endovascular strategy.  相似文献   
983.
Ohne Zusammenfassung Rechtsreferendar Mario Kaufmann, Wiss. Hilfskraft am Lehrstuhl für V?lkerrecht, Europarecht, Europ?isches und Internationales Wirtschaftsrecht (Prof. Dr. Stephan Hobe) an der Universit?t zu K?ln, Neusser Stra?e 285, D-50733 K?ln  相似文献   
984.
985.

Introduction

Floating knee is a flail knee joint resulting from fractures of the shafts or adjacent metaphyses of the femur and the ipsilateral tibia. It is usually associated with several complications and mortality. This study was designed to present our experience with the treatment of this injury.

Material and method

This study was performed between January 2004 and December 2014. 224 cases of floating knee injuries gathered from the 34,480 lower extremities trauma files were studied, and the target information recorded. The injuries most frequently occurred in subjects between 16 and 35 years of age (60.71%), and in male subjects (85.71%). The most frequent mechanism of injury was traffic accident (92.85%). External fixation was the common type of treatment (82.14%) in emergency or as a definitive treatment. The treatment was performed within 24?h of the trauma. We performed a 36-month follow up with clinical examination, radiographs, assessing the complications, and using the Modified Cincinnati Rating System Questionnaire (MCRSQ) and the Karlström/Olerud Score (KOS) to evaluate the progression of the outcomes.

Results

Early complications included 8 cases of compartment syndrome, 60 open fractures and 24 partially amputated limbs. A total amputation was performed in 3 patients. The most common late complication was heterotopic calcifications of the knee (n?=?68, 30.6%). Good scores for MCRSQ and KOS were obtained only after patients were sent to a reference center for knee surgery.

Conclusions

Our experience revealed that the complication rate associated with floatingknee injuries remains high, regardless of the performed treatment. Surgeons should focus on reducing complications while treating these severe injuries.  相似文献   
986.

Background

It is still unclear why many individuals with a cam morphology of the hip do not experience pain. It was recently reported that a decreased femoral neck-shaft angle may also be associated with hip symptoms. However, the effects that different femoral neck-shaft angles have on hip stresses in symptomatic and asymptomatic individuals with cam morphology remain unclear.

Questions/purposes

We examined the effects of the cam morphology and femoral neck-shaft angle on hip stresses during walking by asking: (1) Are there differences in hip stress characteristics among symptomatic patients with cam morphology, asymptomatic individuals with cam morphology, and individuals without cam morphology? (2) What are the effects of high and low femoral neck-shaft angles on hip stresses?

Methods

Six participants were selected, from a larger cohort, and their cam morphology and femoral neck-shaft angle parameters were measured from CT data. Two participants were included in one of three groups: (1) symptomatic with cam morphology; (2) asymptomatic with a cam morphology; and (3) asymptomatic control with no cam morphology with one participant having the highest femoral neck-shaft angle and the other participant having the lowest in each subgroup. Subject-specific finite element models were reconstructed and simulated during the stance phase, near pushoff, to examine maximum shear stresses on the acetabular cartilage and labrum.

Results

The symptomatic group with cam morphology indicated high peak stresses (6.3–9.5 MPa) compared with the asymptomatic (5.9–7.0 MPa) and control groups (3.8–4.0 MPa). Differences in femoral neck-shaft angle influenced both symptomatic and asymptomatic groups; participants with the lowest femoral neck-shaft angles had higher peak stresses in their respective subgroups. There were no differences among control models.

Conclusions

Our study suggests that the hips of individuals with a cam morphology and varus femoral neck angle may be subjected to higher mechanical stresses than those with a normal femoral neck angle.

Clinical Relevance

Individuals with a cam morphology and decreased femoral neck-shaft angle are likely to experience severe hip stresses. Although asymptomatic participants with cam morphology had elevated stresses, a higher femoral neck-shaft angle was associated with lower stresses. Future research should examine larger amplitudes of motion to assess adverse subchondral bone stresses.
  相似文献   
987.
988.
The genus Pestivirus comprises globally distributed members of the family Flaviviridae, which cause severe losses in livestock. The most common species of the genus are bovine viral diarrhoea virus type 1 (BVDV‐1) and type 2 (BVDV‐2), classical swine fever virus (CSFV) and border disease virus (BDV). Recently, a novel ovine pestivirus was repeatedly detected in aborted lamb foetuses on a farm located in the Brescia Province (Italy). Complete genome characterization of this isolate showed that it was highly divergent from known pestivirus species and that it was genetically closely related to CSFV. The aim of this study was to determine the serological relatedness between the identified novel pestivirus and BVDV, BDV and CSFV selected strains for which homologous serum was available, by antigenic characterization performed using cross‐neutralization assays. The serological relatedness was expressed as the coefficient of antigenic similarity (R). Both field and specific antisera raised against the ovine pestivirus neutralized the CSFV reference strain Diepholz with titres significantly higher than those specific for the BDV and BVDV strains. Furthermore, the calculated R values clearly indicated that the novel ovine pestivirus is antigenically more related to CSFV than to ruminant pestiviruses, in agreement with the results of the genomic analysis. This would have severe consequences on CSFV serology in the event of a switch to porcine hosts with implications for CSFV surveillance and porcine health management.  相似文献   
989.
990.
Background

Chronic Kidney Disease (CKD) and its clinical evolution are an emerging issue, due to an increasingly aging population. Consequently, the evaluation of integrative strategies to manage the decline in renal function is warranted. The previous evidence indicates that a biophysical integrated approach can significantly improve renal function. Nevertheless, controlled trials assessing the clinical efficacy of this strategy are still needed.

Methods

A 12-month controlled study was designed to assess the clinical outcome of a group of elderly patients affected by stage II/IIIa CKD randomly assigned to either control or biophysical treatment. In addition to the standard treatment with renin–angiotensin–aldosterone system inhibitors, the biophysical group underwent electromagnetic information transfer through aqueous system procedure every 3 months. Estimated glomerular filtration rate (eGFR), according to CKD–epidemiology collaboration formula, was calculated at baseline and every 3 months.

Results

A total of 238 patients were included in the study, 118 (73.9?±?3.8 years) in the biophysical therapy group and 120 (74.6?±?4.2 years) in the control group. At baseline, mean eGFR was 69?±?11.8 ml/min in the biophysical group and 70.7?±?11.5 ml/min in the control group. After 1 year, eGFR was 74.1?±?12.3 ml/min in the biophysical group, compared to 66.3?±?11.9 ml/min in the control group, with a statistically significant difference between groups (p?<?0.0001). The observed improvement in eGFR in the biophysical group was independent of age, gender, and antihypertensive treatment.

Conclusion

This study shows a potential contribution of a biophysical integrated strategy to support renal function against its natural decline in the elderly, warranting further clinical evaluation.

  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