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   28340篇
  免费   2283篇
  国内免费   1084篇
耳鼻咽喉   286篇
儿科学   251篇
妇产科学   197篇
基础医学   5973篇
口腔科学   667篇
临床医学   2833篇
内科学   3708篇
皮肤病学   151篇
神经病学   3630篇
特种医学   1425篇
外国民族医学   1篇
外科学   3726篇
综合类   3183篇
预防医学   875篇
眼科学   585篇
药学   2917篇
  3篇
中国医学   984篇
肿瘤学   312篇
  2023年   380篇
  2022年   504篇
  2021年   880篇
  2020年   945篇
  2019年   853篇
  2018年   868篇
  2017年   825篇
  2016年   737篇
  2015年   815篇
  2014年   1404篇
  2013年   1646篇
  2012年   1323篇
  2011年   1494篇
  2010年   1272篇
  2009年   1236篇
  2008年   1280篇
  2007年   1350篇
  2006年   1238篇
  2005年   1096篇
  2004年   1041篇
  2003年   1015篇
  2002年   845篇
  2001年   728篇
  2000年   614篇
  1999年   558篇
  1998年   541篇
  1997年   561篇
  1996年   480篇
  1995年   492篇
  1994年   447篇
  1993年   408篇
  1992年   392篇
  1991年   388篇
  1990年   325篇
  1989年   296篇
  1988年   265篇
  1987年   233篇
  1986年   185篇
  1985年   254篇
  1984年   223篇
  1983年   126篇
  1982年   203篇
  1981年   181篇
  1980年   144篇
  1979年   129篇
  1978年   123篇
  1977年   103篇
  1976年   101篇
  1975年   41篇
  1974年   39篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
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   
2.
3.
4.
Ochratoxin A (OTA) is a mycotoxin that mainly causes nephrotoxicity. The single nephrotoxicity of OTA exposure on glomeruli or renal tubule had been well documented, however, the comparison toxicity between it is still unclear. Here, C57BL/6 mice and two types of nephrocyte were treated with concentration-gradient OTA to explore its differentiation nephrotoxicity. Results showed that OTA induced nephrotoxicity in vivo and in vitro, manifested as the deteriorative kidney function in mice and the cut-down cell viability in nephrocyte. Besides, results of murine kidney pathological section and IC50 of two types nephrocyte indicated that OTA-induced toxicity in renal tubule was higher than its in glomeruli. In addition, OTA exposure induced autophagy signaling differentiation expression. It revealed that autophagy was implicated in OTA-induced differential nephrotoxicity in glomeruli and renal tubule. Altogether, we proved that OTA induces a differentiation nephrotoxicity in glomeruli and renal tubule, and it is related to autophagy differential regulation.  相似文献   
5.
背景 孕产妇尿失禁(UI)发病率高,严重影响了女性生活质量。研究表明,盆底肌训练是UI有效的防治手段,本研究前期进行了一项随机对照试验(RCT),结果发现相比于常规宣教,基于移动医疗APP的盆底肌训练并未显现出预防优势,其原因需要进一步深入探讨。 目的 本研究拟对一项基于APP的妊娠期盆底肌训练的干预研究的阴性结果进行探索性分析,旨在探讨产后UI预防效果的影响因素以及获益的亚组人群。 方法 本研究数据来源于前期开展的一项RCT,采用方便抽样法,于2020年6—10月在南方医科大学深圳医院产科门诊招募了126例研究对象,采用随机数字表法分为干预组与对照组,每组各63例。对照组采用常规护理,干预组在此基础上使用"有爱屋"APP进行尿失禁自我管理,干预周期为2个月。产后42 d随访时收集两组产后相关资料,包括产后42 d UI发生情况。以产后是否发生UI为结局指标,将研究对象分为病例组和对照组,采用Logistic回归分析探讨混杂因素及其与干预方式之间的交互作用对产后UI发生的影响。针对Logistic回归分析的结果进行分层分析,探讨是否存在能从APP干预中获益的亚组人群。 结果 病例组和对照组阴道分娩史、入组时存在UI、Broome盆底肌自我效能量表(BPMSES)得分比较,差异均有统计学意义(P<0.05)。Logistic回归分析结果显示,入组时存在UI是产后发生UI的危险因素〔OR=15.897,95%CI(4.724,53.495),P<0.001〕;BPMSES得分与干预方式的交互作用可影响产后UI的发生〔OR=1.034,95%CI(1.017,1.051),P<0.001〕。分层分析结果显示,入组时存在UI症状的孕妇,干预组产后UI发生率低于对照组(χ2=4.18,P=0.041);入组时不存在UI症状的孕妇,两组产后UI发生率比较,差异无统计学意义(χ2=1.89,P=0.284)。 结论 推荐有UI症状的孕妇使用"有爱屋"APP或许可预防产后UI的发生。而对于妊娠期没有UI症状的人群使用"有爱屋"APP预防产后UI发生的证据尚不充分。另外,不管有无UI症状,盆底肌训练自我效能高的孕妇有望从APP干预中获益。  相似文献   
6.
Postbariatric loss of muscle tissue could negatively affect long-term health due to its role in various bodily processes, such as metabolism and functional capacity. This meta-analysis aimed to unravel time-dependent changes in the magnitude and progress of lean body mass (LBM), fat-free mass (FFM), and skeletal muscle mass (SMM) loss following bariatric surgery. A systematic literature search was conducted in Pubmed, Embase, and Web of Science. Fifty-nine studies assessed LBM (n = 37), FFM (n = 20), or SMM (n = 3) preoperatively and ≥1 time points postsurgery. Random-effects meta-analyses were performed to determine pooled loss per outcome parameter and follow-up time point. At 12-month postsurgery, pooled LBM loss was ?8.13 kg [95%CI ?9.01; ?7.26]. FFM loss and SMM loss were ?8.23 kg [95%CI ?10.74; ?5.73] and ?3.18 kg [95%CI ?5.64; ?0.71], respectively. About 55% of 12-month LBM loss occurred within 3-month postsurgery, followed by a more gradual decrease up to 12 months. Similar patterns were seen for FFM and SMM. In conclusion, >8 kg of LBM and FFM loss was observed within 1-year postsurgery. LBM, FFM, and SMM were predominantly lost within 3-month postsurgery, highlighting that interventions to mitigate such losses should be implemented perioperatively.  相似文献   
7.
目的:探讨萆苓祛痛方对糖尿病痛风大鼠骨骼肌组织去乙酰化酶3(SIRT3)蛋白表达及尿酸盐转运体1(URAT1) mRNA的影响。方法:选择健康雄性大鼠40只,除正常组外,其余组予高脂饲料喂养并联合小剂量链脲佐菌素(STZ)溶液40 mg·kg-1腹腔注射1次,以血糖≥16. 7 mmol·L-1,为糖尿病模型。4 d后关节腔注射5%尿酸钠溶液1次,诱导痛风模型,模型成功后,分为萆苓祛痛方组(萆苓组,10 g·kg-1),吲哚美辛组(5 mg·kg-1),吡格列酮组(10 mg·kg-1),均连续给药21 d,正常组、模型组予等量生理盐水;采用蛋白免疫印迹法(Western blot)测定骨骼肌组织SIRT3蛋白表达;实时荧光定量聚合酶链式反应(Real-time PCR)检测骨骼肌组织URAT1 mRNA表达,并进行病理检查,取血测定血糖(GLU),血尿酸(UA)及C反应蛋白(CRP)含量。结果:与正常组比较,模型组GLU,UA及CRP明显升高(P 0. 01);与模型组比较,萆苓组、吡格列酮组血糖下降(P 0. 05);各药物组UA及CRP明显下降(P 0. 01)。与正常组比较,模型组骨骼肌SIRT3蛋白表达量显著降低(P 0. 01);与模型组比较,萆苓组骨骼肌SIRT3蛋白表达量显著提高(P 0. 01),与西药组比较无明显差异;条带图的结果同样显示,与正常组比较,模型组表达亮度明显减弱,药物组表达亮度明显增强;与正常组比较,模型组关节组织URAT1 mRNA相对表达量明显升高(P 0. 01);与模型组比较,各药物组URAT1 mRNA相对表达量显著下调(P 0. 01)。电泳图同样提示,正常组表达亮度减弱,模型组表达亮度显著增强,萆苓组、西药组表达亮度明显减弱。关节病理提示,与正常组比较,模型组大鼠关节病理损伤严重,可见大量炎细胞浸润及纤维增生,滑膜细胞变性、坏死。与模型组比较,萆苓祛痛方关节病变程度明显减低,见少量炎细胞浸润,滑膜上皮轻度增生。结论:具有泻浊解毒通络作用的萆苓祛痛方可显著提高糖尿病痛风大鼠骨骼肌组织SIRT3的蛋白表达量,下调URAT1 mRNA的表达量,减轻骨骼肌组织病理损伤,减低血清炎症因子CRP的含量,降低模型大鼠的血糖、血尿酸水平,有保护关节功能的作用。  相似文献   
8.

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   
9.
10.
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