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   2578篇
  免费   153篇
  国内免费   8篇
耳鼻咽喉   18篇
儿科学   153篇
妇产科学   43篇
基础医学   283篇
口腔科学   55篇
临床医学   144篇
内科学   604篇
皮肤病学   81篇
神经病学   83篇
特种医学   100篇
外科学   551篇
综合类   39篇
预防医学   96篇
眼科学   124篇
药学   195篇
中国医学   12篇
肿瘤学   158篇
  2023年   36篇
  2022年   53篇
  2021年   119篇
  2020年   71篇
  2019年   92篇
  2018年   125篇
  2017年   67篇
  2016年   50篇
  2015年   85篇
  2014年   128篇
  2013年   107篇
  2012年   175篇
  2011年   175篇
  2010年   124篇
  2009年   95篇
  2008年   143篇
  2007年   186篇
  2006年   136篇
  2005年   117篇
  2004年   76篇
  2003年   94篇
  2002年   74篇
  2001年   38篇
  2000年   41篇
  1999年   45篇
  1998年   24篇
  1997年   13篇
  1996年   12篇
  1994年   11篇
  1993年   5篇
  1992年   17篇
  1991年   13篇
  1990年   8篇
  1989年   14篇
  1988年   10篇
  1987年   5篇
  1986年   6篇
  1985年   6篇
  1984年   10篇
  1979年   13篇
  1978年   11篇
  1977年   5篇
  1976年   11篇
  1975年   5篇
  1973年   10篇
  1972年   5篇
  1971年   7篇
  1970年   11篇
  1969年   13篇
  1963年   5篇
排序方式: 共有2739条查询结果,搜索用时 15 毫秒
121.
122.
European Radiology - To have a global picture of the recurrent use of CT imaging to a level where cumulative effective dose (CED) to individual patients may be exceeding 100 mSv at which organ...  相似文献   
123.
Background

The most common abnormal spirometric pattern reported in WTC worker and volunteer cohorts has consistently been that of a nonobstructive reduced forced vital capacity (low FVC). Low FVC is associated with obesity, which is highly prevalent in these cohorts. We used quantitative CT (QCT) to investigate proximal and distal airway inflammation and emphysema in participants with stable low FVC pattern.

Methods

We selected study participants with at least two available longitudinal surveillance spirometries, and a chest CT with QCT measurements of proximal airway inflammation (wall area percent, WAP), end-expiratory air trapping, suggestive of distal airway obstruction (expiratory to inspiratory mean lung attenuation ratio, MLAEI), and emphysema (percentage of lung volume with attenuation below − 950 HU, LAV%). The comparison groups in multinomial logistic regression models were participants with consistently normal spirometries, and participants with stable fixed obstruction (COPD).

Results

Compared to normal spirometry participants, and after adjusting for age, sex, race/ethnicity, BMI, smoking, and early arrival at the WTC disaster site, low FVC participants had higher WAP (ORadj 1.24, 95% CI 1.06, 1.45, per 5% unit), suggestive of proximal airway inflammation, but did not differ in MLAEI, or LAV%. COPD participants did not differ in WAP with the low FVC ones and were more likely to have higher MLAEI or LAV% than the other two subgroups.

Discussion

WTC workers with spirometric low FVC have higher QCT-measured WAP compared to those with normal spirometries, but did not differ in distal airway and emphysema measurements, independently of obesity, smoking, and other covariates.

  相似文献   
124.
Madan  Manu  Kunal  Shekhar 《Clinical rheumatology》2020,39(11):3189-3189
Clinical Rheumatology -  相似文献   
125.

Background

Slipped capital femoral epiphysis (SCFE) is commonly treated with in situ pinning. However, a severe slip may not be suitable for in situ pinning because the required screw trajectory is such that it risks perforating the posterior cortex and damaging the remaining blood supply to the capital epiphysis. In such cases, an anteriorly placed screw may also cause impingement. It is also possible to underestimate the severity of the slip using conventional radiographs. The aim of this study was to describe and evaluate a novel method for calculating the true deformity in SCFE and to assess the interobserver and intraobserver reliability of this technique.

Methods

We selected 20 patients with varying severity of SCFE who presented to our institution. Cross-sectional imaging [either axial computed tomography (CT) scans or magnetic resonance imaging (MRI) scans] and anteroposterior (AP) pelvis radiographs were assessed by four reviewers with varying levels of experience on two occasions. The degree of slip on the axial image and on the AP pelvis radiographs were measured and, from this, the oblique plane deformity was calculated using the method as popularised by Paley. The intraclass correlation coefficient (ICC) was calculated to determine the interobserver and intraobserver reliabilities between and amongst the raters.

Results

The interobserver reliability for the calculated oblique plane deformity in SCFE ICC was 0.947 [95 % confidence interval (CI) 0.90–0.98] and the intraobserver reliability for the calculated oblique plane deformity of individual raters ranged from 0.81 to 0.94. The deformity in the oblique plane was always greater than the deformity measured in the axial or the coronal plane alone.

Conclusion

This method for calculating the true deformity in SCFE has excellent interobserver and intraobserver reliability and can be used to guide treatment options. This technique is a reliable and reproducible method for assessing the degree of deformity in SCFE. It may help orthopaedic surgeons with varying degrees of experience to identify which hips are suitable for in situ pinning and those which require surgical dislocation and anatomical reduction, given that plain radiographs in a single plane will underestimate the true deformity in the oblique plane.

Level of evidence

Level II diagnostic study.  相似文献   
126.
Injury of the ulnar collateral ligament (UCL) of thumb can be incapacitating if untreated or not treated properly. This injury is notorious for frequently being missed by inexperienced health care personnel in emergency departments. It has frequently been described in skiers, but also occurs in other sports such as rugby, soccer, handball, basketball, volleyball and even after a handshake. The UCL of the thumb acts as a primary restraint to valgus stress and is injured if hyperabduction and hyperextension forces are applied to the first metacarpophalangeal joint. The diagnosis is best established clinically, though MRI is the imaging modality of choice. Many treatment options exist, surgical treatment being offered depending on various factors, including timing of presentation (acute or chronic), grade (severity of injury), displacement (Stener lesion), location of tear (mid‐substance or peripheral), associated or concomitant surrounding tissue injury (bone, volar plate, etc.), and patient‐related factors (occupational demands, etc.). This review aims to identify the optimal diagnostic techniques and management options for UCL injury available thus far.  相似文献   
127.
128.
To analyze the clinical profile and outcome of pediatric patients who had undergone a liver and/or RT at our center over a five yr period, case records of all the patients who had undergone a liver or RT were analyzed retrospectively. One hundred solid organ transplants were performed at our center between January 2007 and January 2012. These included 50 liver, 44 renal, one sequential liver and renal, and two CLKT. BA was the most common indication for an LT (38%). At a median follow‐up of two yr three months, the patient survival was 88%. The most common indication for an RT was chronic glomerulonephritis (54.5%). At a median follow‐up of three yr, the survival was 91%. The CLKT were performed for hyperoxaluria. Two yr post LT, a sequential RT was performed for ESRD resulting from transplant associated microangiopathy. All patients received a living related graft. The common post‐operative complications were infections, vascular complications, and graft dysfunction. Survival rates for liver and RT at our center are comparable to those in the established centers in the West.  相似文献   
129.
The study was undertaken to evaluate the reliability of different facial measurements for determination of vertical dimension of occlusion in edentulous subjects using accepted facial dimensions recorded from dentulous subjects. The hypothesis was that facial measurements can be used to obtain the vertical dimension of occlusion for edentulous patients where no pre-extraction records exist. A total of 180 subjects were selected in the age groups of 50–60 years, consisting of 75 dentate male and 75 dentate female subjects for whom different facial measurements were recorded including vertical dimension of occlusion and rest, and 15 edentulous male and 15 edentulous female subjects for whom all the facial measurements were recorded including the vertical dimension of rest and occlusion following construction of upper and lower complete dentures. The left outer canthus of eye to angle of mouth distance and the right Ear–Eye distance were found to be as valuable adjuncts in the determination of occlusal vertical dimension. The Glabella–Subnasion distance, the Pupil–Stomion distance, the Pupil–Rima Oris distance and the distance between the two Angles of the Mouth did not have a significant role in the determination of the occlusal vertical dimension. The vertical dimension can be determined with reasonable accuracy by utilizing other facial measurements for patients for whom no pre-extraction records exist.  相似文献   
130.
We report a 59‐year‐old man who presented with progressive dyspnea of 30 years. His pulmonary function tests showed reduced forced expiratory volume in the first second and forced vital capacity and computed tomography of the chest showed eventration of the left hemi‐diaphragm. He underwent successful laparoscopic stapled resection / plication of the lax hemi‐diaphragm. He was discharged on the fourth postoperative day with the intercostal drain in situ and this was removed 5 days later at follow up. Postoperatively the pulmonary function showed significant improvement and he remains well 2 years after surgery.  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