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   9196篇
  免费   463篇
  国内免费   254篇
耳鼻咽喉   71篇
儿科学   125篇
妇产科学   44篇
基础医学   2348篇
口腔科学   81篇
临床医学   1202篇
内科学   1228篇
皮肤病学   14篇
神经病学   1196篇
特种医学   538篇
外科学   1150篇
综合类   741篇
预防医学   349篇
眼科学   71篇
药学   394篇
  2篇
中国医学   297篇
肿瘤学   62篇
  2023年   87篇
  2022年   233篇
  2021年   351篇
  2020年   321篇
  2019年   263篇
  2018年   262篇
  2017年   216篇
  2016年   181篇
  2015年   208篇
  2014年   447篇
  2013年   458篇
  2012年   399篇
  2011年   407篇
  2010年   334篇
  2009年   398篇
  2008年   424篇
  2007年   399篇
  2006年   418篇
  2005年   343篇
  2004年   294篇
  2003年   321篇
  2002年   257篇
  2001年   229篇
  2000年   209篇
  1999年   164篇
  1998年   132篇
  1997年   130篇
  1996年   131篇
  1995年   139篇
  1994年   128篇
  1993年   118篇
  1992年   108篇
  1991年   101篇
  1990年   106篇
  1989年   77篇
  1988年   100篇
  1987年   86篇
  1986年   79篇
  1985年   91篇
  1984年   109篇
  1983年   45篇
  1982年   74篇
  1981年   53篇
  1980年   43篇
  1979年   56篇
  1978年   52篇
  1977年   48篇
  1976年   36篇
  1973年   54篇
  1972年   46篇
排序方式: 共有9913条查询结果,搜索用时 31 毫秒
1.
2.
BackgroundAdjunct therapies (ATs) may further improve outcomes after botulinum toxin injections in spastic patients, but evidence was unclear in previous systematic reviews.ObjectiveTo assess the efficacy of non-pharmacological ATs in spastic adults according to the International Classification of Functioning, Disability and Health and build an expert consensus-based on a Delphi process.MethodsFour electronic databases were searched up to May 2020 for reports of comparative trials of non-pharmacologic ATs after botulinum toxin injections in spastic adults. Then, 25 French experts participated in a two-round Delphi process to build recommendations on the use of ATs.ResultsWe included 32 studies (1202 participants, median 32/study) evaluating the effects of physical agents (n = 9), joint posture procedures (JPPs, n = 11), and active ATs (n = 14), mainly after stroke. The average quality of articles was good for randomised controlled trials (median [interquartile range] PEDro score = 7 [6–8]) but moderate (n = 2) or poor (n = 2) for non-randomised controlled trials (Downs & Black checklist). Meta-analysis was precluded owing to the heterogeneity of ATs, control groups and outcome measures. There is evidence for the use of JPPs except low-dose manual stretching and soft posture techniques. Continuous postures (by taping or casting) are recommended; discontinuous postures (by orthosis) may be preferred in patients with active function. Device-free or device-assisted active ATs may be beneficial in the mid-term (> 3 months after botulinum toxin injections), particularly when performed at a high-intensity (> 3 h/week) as in constraint-induced movement therapy. Self-rehabilitation remains understudied after a focal treatment, but its interest is highlighted by the experts. The use of physical agents is not recommended.ConclusionsJPPs and active ATs (device-assisted or device-free) may further improve impairments and activities after botulinum toxin injections. Further studies are needed to better define the best strategies for ATs as a function of the individual treatment goals, participation and quality of life.Review RegistrationPROSPERO (CRD42018105856).  相似文献   
3.
目的探讨维持性血液透析(MHD)患者血清维生素D水平对下肢肌力减退的预测作用。 方法横断面研究设计,选择2018年9月至10月于战略支援部队特色医学中心血液净化中心的95例MHD患者,检测其血清25-羟维生素D3[25(OH)D3]水平,采用5次站立-坐下实验(5-STS)评价其下肢肌力。根据5-STS完成时间将MHD患者分为下肢肌力正常组(n=85)与减退组(n=10),比较两组患者人口学特征、实验室指标。采用多因素Logistic回归分析下肢肌力减退的影响因素,绘制受试者工作特征(ROC)曲线分析上述因素预测MHD患者发生下肢肌力减退的特异度和敏感度。 结果95例MHD患者血清25(OH)D3水平为11.00~99.50 nmol/L,中位数31.23(19.90~43.30)nmol/L;5-STS完成时间为3.55 s~18.71 s,中位数9.81(7.12,12.43)s,下肢肌力减退者10例(10.53%)。多因素Logistic回归分析显示,血清25(OH)D3是MHD患者下肢肌力减退的保护性因素[OR=0.761,95%CI(0.592~0.978),P=0.033]。进一步ROC曲线分析显示,25(OH)D3对应的ROC曲线下面积为0.815,其预测MHD患者发生下肢肌力减退的敏感度为80.00%,特异度为80.00%。 结论MHD患者血清25(OH)D3水平普遍较低,下肢肌力减退者更为明显;血清维生素D水平对MHD患者是否存在下肢肌力减退具有较好的预测价值。  相似文献   
4.
PurposeTo prospectively determine the rate of radial artery occlusion (RAO) in patients undergoing transradial access for intra-arterial interventions.Materials and MethodsSeventy-seven patients undergoing transradial access from August 2019 to March 2021 for 120 intra-arterial procedures (yttrium-90 mapping [n = 39] and radioembolization [n = 38], uterine artery embolization [n = 19], transarterial chemoembolization [n = 10], active bleed embolization [n = 8], angiomyolipoma embolization [n = 4], and other [n = 2]) were enrolled. The average patient age was 59 years ± 13.1 (range, 30–90 years), and 43 (55.8%) of the 77 patients were men. The patients underwent radial artery (RA) palpation, ultrasound evaluation, the Barbeau test, and the reverse Barbeau test prior to and following the intervention. Verapamil, nitroglycerin, and heparin were administered in a total of 114 (95%) of the 120 procedures prior to starting the procedure. The incidence of RAO and radial artery spasm (RAS) was calculated, and univariate logistic regression was performed to analyze the predictors of RAS.ResultsThe preprocedural RA diameter (3.0 mm ± 0.67) was not significantly different from the postprocedural RA diameter (3.0 mm ± 0.65, P = .904). The RAO rate was determined to be 0.8% (1/120), and this artery recanalized within 1 week. Due to the small number of occlusions, statistical analysis of predictors of RAO was not performed. The rate of RAS was 22.7% (27/119). None of the variables tested—including age, sex, RA diameter, initial versus repeat access, operator experience, and artery puncture technique—showed significant prediction for RAS. Patients were seen for follow-up after 111 (92.5%) of the 120 procedures.ConclusionsTransradial access resulted in a <1% rate of RAO.  相似文献   
5.
BackgroundFalls in older persons are associated with muscle mass and strength alterations, which may also affect balance parameters. However, the most appropriate combined approach to assess muscle and balance components that predict falls in older persons is still lacking.Research questionWe hypothesized that appendicular lean and/or mid-thigh mass and muscle strength and performance are positively associated with balance indices and fall risk in older persons.MethodsCross-sectional analyses of retrospective data from 260 participants with risk and/or history of falls examined at a Falls and Fracture Clinic. Assessments included a comprehensive clinical exam, bone densitometry and body composition by DXA, grip strength, gait speed, posturography, timed up and go (TUG) and four-square step (FSST) tests. Retrospective falls and fracture history was collected. Associations between appendicular and mid-thigh lean mass and muscle strength/performance vs balance indicators were determined before and after adjusting for age and gender.ResultsMean age of participants was 78 ± 6.7 (65−96) years. Both appendicular and mid-thigh lean masses corrected for BMI (but not for height2), and muscle strength and performance measures are associated with better dynamic balance. Conversely, static balance indicators showed less consistent associations with lean mass. Only TUG and sit to stand time consistently showed significant associations with most static balance indicators.SignificanceCombined with strength and performance parameters, ALM and mid-thigh estimates adjusted by BMI strongly correlate with dynamic balance parameters and could become practical elements of falls risk assessment as well as markers of therapeutic response to falls prevention interventions.  相似文献   
6.
《Indian heart journal》2022,74(3):182-186
BackgroundIt has been reported that significant endothelial dysfunction or clinically evident vasospasm can be associated with drug-eluting stents (DESs). However, the impact of DES associated coronary artery spasm (CAS) on long-term clinical outcomes has not been fully elucidated as compared with those of patients with vasospastic angina.MethodsA total of 2797 consecutive patients without significant coronary artery lesion (<70%), who underwent the Acetylcholine (Ach) provocation test, were enrolled between Nov 2004 and Oct 2010. DES-associated spasm was defined as significant CAS in proximal or distal to previously implanted DES site at follow-up angiography with Ach test. Patients were divided into two groups (DES-CAS; n = 108, CAS; n = 1878). For adjustment, propensity score matching (PSM) was done (C-statistics = 0.766, DES-CAS; n = 102, CAS; n = 102). SPSS 20 (Inc., Chicago, Illinois) was used to analyze this data.ResultsBaseline characteristics were worse in the DES-CAS group. After PSM, both baseline characteristics and the Ach test results were balanced except higher incidence of diffuse CAS and ECG change in the DES-CAS group. During Ach test, the incidence of diffuse spasm (93.1% vs. 81.3%, p = 0.012) and ST-T change (10.7% vs. 1.9%, p = 0.010) were higher in the DES-CAS group. At 3-year, before and after adjustment, the DES-CAS group showed a higher incidence of coronary revascularization (9.8% vs. 0.0%, p = 0.001), recurrent chest pain requiring follow up coronary angiography (CAG, 24.5% vs. 7.8%, p = 0.001) and major adverse cardiac events (MACEs, 9.8% vs. 0.9%, p < 0.005).ConclusionIn this study, DES associated CAS was associated with higher incidence of diffuse spasm, ST-T change and adverse 3-year clinical outcomes. Special caution should be exercised in this particular subset of patients.  相似文献   
7.
钟凯华 《安徽医药》2022,26(11):2265-2269
目的分析长臂单轴椎弓根螺钉经 Wiltse入路在单纯性胸腰椎压缩性骨折中的应用效果及对肌肉损伤的影响。方法选取自 2018年 1月至 2020年 8月周口市中心医院收治的单纯性胸腰椎压缩性骨折病人 87例,根据复位固定术式不同,分为观察组 38例、对照组 49例,其中观察组采取长臂单轴椎弓根螺钉经 Wiltse入路,对照组采取 AF系统经传统后正中入路。记录两组病人围术期指标、手术前后血清肌肉损伤指标[肌酸激酶( CK)、肌红蛋白( Mb)]变化;采用疼痛视觉模拟评分( VAS)评价病人不同时间节点疼痛水平;经胸腰椎正侧位片检查获取伤椎原始高度( H0)、术前及术后 1周伤椎椎体前缘高度( H1H2),计算术前、术后 1周伤椎相对高度( H1/H0、H2/H0)及伤椎复位率,并测量矢状位 Cobb角变化;随访 3个月,采用 Oswestry功能障、碍指数( ODI)评价功能障碍情况,并统计手术相关并发症。结果观察组手术时长、术中失血量、术后引流量及首次下床活动时间均明显短于或低于对照组( P<0.05)。术后 3d,两组血清 CK、Mb水平均较术前升高( P<0.05),且观察组血清 CK、Mb水平  相似文献   
8.
9.

Objectives

Short successive periods of skeletal muscle disuse have been suggested to substantially contribute to the observed loss of skeletal muscle mass over the life span. Hospitalization of older individuals due to acute illness, injury, or major surgery generally results in a mean hospital stay of 5 to 7 days, during which the level of physical activity is strongly reduced. We hypothesized that hospitalization following elective total hip arthroplasty is accompanied by substantial leg muscle atrophy in older men and women.

Design and participants

Twenty-six older patients (75 ± 1 years) undergoing elective total hip arthroplasty participated in this observational study.

Measurements

On hospital admission and on the day of discharge, computed tomographic (CT) scans were performed to assess muscle cross-sectional area (CSA) of both legs. During surgery and on the day of hospital discharge, a skeletal muscle biopsy was taken from the m. vastus lateralis of the operated leg to assess muscle fiber type–specific CSA.

Results

An average of 5.6 ± 0.3 days of hospitalization resulted in a significant decline in quadriceps (?3.4% ± 1.0%) and thigh muscle CSA (?4.2% ± 1.1%) in the nonoperated leg (P < .05). Edema resulted in a 10.3% ± 1.7% increase in leg CSA in the operated leg (P < .05). At hospital admission, muscle fiber CSA was smaller in the type II vs type I fibers (3326 ± 253 μm2 vs 4075 ± 279 μm2, respectively; P < .05). During hospitalization, type I and II muscle fiber CSA tended to increase, likely due to edema in the operated leg (P = .10).

Conclusions

Six days of hospitalization following elective total hip arthroplasty leads to substantial leg muscle atrophy in older patients. Effective intervention strategies are warranted to prevent the loss of muscle mass induced by short periods of muscle disuse during hospitalization.  相似文献   
10.
Immunity-related GTPase family M1 protein (lRGM1) plays an important role in host resistance to infection, immune inflammation, and tumors, and it is expressed in various tissues and cells, including the central nervous system, cardiovascular system, bone marrow-derived cells, glioma, and melanoma. However, the effect of IRGM1 in the muscles has not been reported to date. In this study, Irgm1−/− mice were used to evaluate the effect of lrgm1 on regeneration after skeletal muscle injury. The tibialis anterior muscle in Irgm1−/− mice was poorly repaired after BaCl2-induced injury, whereas lrgm1 knockout itself had no significant effect on the differentiation of myoblasts. However, the microenvironment of Irgm1−/− mice with a high interferon-gamma level inhibited the differentiation of myoblasts in vivo. These results suggest that lrgm1 knockout indirectly inhibits skeletal muscle regeneration after injury, providing new insights into the biological function of IRGM1.  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