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   2103篇
  免费   150篇
  国内免费   28篇
耳鼻咽喉   12篇
儿科学   32篇
妇产科学   27篇
基础医学   272篇
口腔科学   105篇
临床医学   196篇
内科学   317篇
皮肤病学   3篇
神经病学   133篇
特种医学   80篇
外科学   209篇
综合类   233篇
预防医学   222篇
眼科学   161篇
药学   157篇
  3篇
中国医学   57篇
肿瘤学   62篇
  2024年   5篇
  2023年   58篇
  2022年   92篇
  2021年   141篇
  2020年   129篇
  2019年   101篇
  2018年   97篇
  2017年   74篇
  2016年   79篇
  2015年   63篇
  2014年   125篇
  2013年   173篇
  2012年   103篇
  2011年   121篇
  2010年   74篇
  2009年   107篇
  2008年   93篇
  2007年   93篇
  2006年   78篇
  2005年   68篇
  2004年   58篇
  2003年   38篇
  2002年   32篇
  2001年   27篇
  2000年   29篇
  1999年   17篇
  1998年   24篇
  1997年   20篇
  1996年   20篇
  1995年   19篇
  1994年   8篇
  1993年   9篇
  1992年   11篇
  1991年   9篇
  1990年   9篇
  1989年   11篇
  1988年   5篇
  1987年   7篇
  1986年   5篇
  1985年   8篇
  1984年   5篇
  1983年   4篇
  1982年   7篇
  1981年   9篇
  1980年   6篇
  1979年   2篇
  1978年   4篇
  1977年   2篇
  1976年   1篇
  1974年   1篇
排序方式: 共有2281条查询结果,搜索用时 15 毫秒
41.
42.
《The Knee》2020,27(6):1801-1810
BackgroundGenu varum is one of the most common anatomical variations of knee alignment which is considered a risk factor for anterior knee pain and anterior cruciate ligament injury among football players. Considering that millions of children participate in high-level football training, the purpose of this study was to determine the genu varum development in adolescent football players and non-athlete peers. The hypothesis of this study was that genu varum incidence was higher in adolescent football players compared with non-athletic peers.MethodsThe design was a cross-sectional study. Two-hundred and thirty-seven male football players (FG) and aged-matched and anthropometrically similar non-athletes (CG) were recruited into the study. The quadriceps angle and intercondylar–intermalleolar distance were measured to evaluate the leg alignment. The distance between the medial edges of the condyles and malleoli was measured in millimeters using a digital caliper while angle measurements were performed using a photographic technique in a standing position. To analyze the variables, comparison, correlation and regression statistical tests were performed.ResultsThe intercondylar–intermalleolar distance and quadriceps angle values were significantly higher in FG than CG in all ages. In FG, a very strong correlation was found between number of training years and the intercondylar–intermalleolar distance. The prevalence of genu varum was markedly higher in FG than CG (~37% vs. 2%, respectively) based on intercondylar–intermalleolar distance.ConclusionThis study determined that the prevalence of genu varum and abnormal quadriceps angles in adolescent football players is significantly higher compared with their non-athletic peers.  相似文献   
43.
44.
45.
We evaluated the efficacy of rehabilitation therapy with Hybrid Assistive Limb® (HAL; hereafter HAL therapy) in three patients diagnosed with sporadic inclusion body myositis (sIBM) who were hospitalized to undergo HAL therapy. Among them, one patient participated in eight courses and the other two in two courses of HAL therapy between 2017 and 2020. We determined the mean rate of improvement in two-minute walking distance and 6 m walking speed at the time of hospital discharge. After HAL therapy, we confirmed the patients’ desire to continue the use of HAL. In one patient, we observed improvements of 146.0% and 120.0% in two-minute walk and 6 m walking speed, respectively, after the first course of HAL therapy; these values are 133.7% and 130% after the eighth course of HAL therapy. These values exceeded 90% in the other two patients after the second course of HAL therapy. HAL therapy maintained both quantity and quality of ambulation and showed positive psychological effects on patient conditions because it reduces exercise load and facilitates safety. While HAL therapy might be effective in maintaining and improving ambulation in patients with sIBM, we should consider to discontinue HAL therapy as it increased risk of falling.  相似文献   
46.
The purpose of this study was to examine satisfaction with and outcomes of a real-time Internet-based group exercise program for older adults. Men and women age 50 and older (mean = 66.5) were recruited to participate in a 10-week distance group exercise program. Paired sample t-tests revealed that Sit-To-Stand (STS) repetitions increased significantly (p = .009), while Timed Up-and-Go(TUG) time decreased significantly (p = .000). Connectivity, visibility, and communication emerged as themes related to the use of technology; but overall, real-time Internet-based technology was shown to be an effective way to present group exercise programs for older adults in this rural setting.  相似文献   
47.
Nutritional studies in patients with chronic obstructive pulmonary disease (COPD) are often based on oral nutritional supplementation and are of short duration. Our aim was to study the changes in body weight and physical performance in COPD patients after receiving the dietary advice for 1 year. Thirty-six patients with COPD as a primary diagnosis (mean age: 68.5 ± 7.8 years), referred to a pulmonary rehabilitation program were studied. Each patient received dietary advice individually. Body weight had increased significantly by 1.3 kg (p = 0.02) and walking distance by 83.2 m (p = 0.007) after 1 year. There was an increase in mean handgrip strength after 1 year (1.6 kg, p = 0.07). The mean intake of energy and protein expressed as percent of energy and protein requirement had increased after 1 year (15%, p < 0.001, and 5.6%, p = 0.09, respectively). Handgrip strength correlated significantly with energy (r = 0.53, p = 0.002), fat (r = 0.50, p = 0.02) and protein intake (r = 0.41, p = 0.002) after 1 year. In conclusion, positive effects on body weight, handgrip strength and walking distance in patients with COPD were seen after receiving dietary advice with a 1-year follow-up.  相似文献   
48.
《Injury》2016,47(6):1302-1308
BackgroundAs a predictor of the risk of lag screw cutout, it was recommended that keeping tip-apex distance (TAD) < 25 mm and placing the screw centrally or inferiorly, but positioning the lag screw too inferiorly in the head would produce TAD > 25 mm. We aim to simulate various positions of the lag screw in the femoral head and identify whether 25 mm is a suitable cut-off value that favours all sizes of femoral heads with intertrochanteric fractures of the hip.MethodsUsing a general mathematical software, the positions of the screw tip points were simulated. The virtual anterior–posterior and lateral views were then visualised, and the locus of the screw tips was projected into a Cartesian coordinate system according to the TAD and calcar-referenced tip-apex distance (CalTAD) formulas. Each original virtual anterior–posterior and lateral image was zoomed and compiled to match a calculated average image. The screw tip points were recorded, traced and compiled into volumes which could be used to visualise the screw's movements and positioning within the femoral head. The extracted volumes were calculated when 10 mm < TAD < 25 mm and 10 mm < CalTAD < 25 mm, and the region where these two volumes overlapped was also calculated. Suitable positions for the screw tip were then assessed.ResultsFor the TAD calculation, the shape of the traced screw tip points had a pancake-like appearance, while the CalTAD plot produced a teardrop-shaped region. The volume ratios of TAD, CalTAD and overlapping region relative to the femoral head volume were respectively 3.51 ± 1.30%, 5.19 ± 1.62% and 2.64 ± 1.32%. The volumes of the traced TAD, CalTAD and overlapping regions increased slower than the volume of an idealised sphere.ConclusionPositioning the lag screw should address geometrical effects of both tip-apex distance and femoral head size, with an emphasis on measuring the position of the screw tip for the suitable zone by volume ratio. The previous 25 mm TAD cut-off value should be adjusted according to the individual femoral head size.  相似文献   
49.
The percutaneous placement of lateral distal humeral pins risks injury to the radial nerve. We aimed to provide a reliable and safe parameter for the insertion of lateral distal humeral pins. A secondary aim of this study was to investigate the effect of pin/screw placement in the intended zone of fixation at the lateral distal humerus. We dissected 70 fresh cadaveric upper limbs and the radial nerve was identified and its course followed into the anterior compartment. The point where the radial nerve crosses humerus in mid lateral plane was identified and the distance between this point and lateral epicondyle was measured, as was the maximum trans‐epicondylar distance, along with the olecranon fossa height. Statistical analysis was performed using the Pearson correlation coefficient. The average trans‐epicondylar distance was measured at 62 ± 6 mm (range 52–78 mm), and the average lateral radial nerve height was 102 ± 10 mm (range 75–129 mm). The ratio of the lateral nerve height to the trans‐epicondylar distance was an average of 1.7 ± 0.2 (range 1.4–2.0). The Pearson correlation coefficient between the lateral nerve height and the trans‐epicondylar distance was r = 0.95. A relative dimension, the trans‐epicondylar distance is both reliable and easily accessible to the operating surgeon. The absolute safe zone for pin entry into the lateral distal humerus is that area lying within the caudad 70% of a line, equivalent in length to the patient's own trans‐epicondylar distance, when projected proximally from the lateral epicondyle. Clin. Anat. 22:684–688, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   
50.

Objective

To evaluate the effect of pulmonary rehabilitation (PR) on exercise performance and quality of life in patients with chronic obstructive pulmonary disease (COPD) with different degrees of static lung hyperinflation (LH).

Design

Retrospective cohort study.

Setting

PR network.

Participants

A cohort of 1981 patients with COPD (55% men; age: 66.8±9.3y; forced expiratory volume in the first second%: 50.7±19.5; residual volume [RV]%: 163.0±49.7).

Intervention

An interdisciplinary PR program for patients with COPD consisting of 40 sessions.

Main Outcome Measures

Participants were stratified into 5 quintiles according to baseline RV and were evaluated on the basis of pre- and post-PR 6-minute walk distance (6MWD), constant work rate test (CWRT), and Saint George’s Respiratory Questionnaire (SGRQ), among other clinical parameters.

Results

With increasing RV quintile, patients were younger, more frequently women, had lower forced expiratory volume in the first second%, lower body mass index and fat-free mass index, shorter 6MWD, shorter CWRT, and worse SGRQ scores (P<.01). All RV strata improved after PR in all 3 outcomes (P<.001). Nevertheless, higher, compared to lower RV categories, had lower ΔCWRT (P<.01) but similar Δ6MWD (P=.948) and ΔSGRQ (P=.086) after PR.

Conclusions

LH in COPD is related to younger age, female sex, lower body weight, worse exercise capacity and health status, but did not prevent patients from benefitting from PR. LH, however, influences walking and cycling response after PR differently.  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