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   87824篇
  免费   8282篇
  国内免费   2457篇
耳鼻咽喉   666篇
儿科学   2254篇
妇产科学   659篇
基础医学   4988篇
口腔科学   542篇
临床医学   14655篇
内科学   22042篇
皮肤病学   520篇
神经病学   4748篇
特种医学   3095篇
外国民族医学   2篇
外科学   8811篇
综合类   15199篇
现状与发展   4篇
一般理论   1篇
预防医学   5260篇
眼科学   968篇
药学   7745篇
  111篇
中国医学   4844篇
肿瘤学   1449篇
  2024年   327篇
  2023年   1557篇
  2022年   2999篇
  2021年   4359篇
  2020年   4247篇
  2019年   3606篇
  2018年   3321篇
  2017年   3386篇
  2016年   3288篇
  2015年   3079篇
  2014年   6022篇
  2013年   5814篇
  2012年   4653篇
  2011年   4982篇
  2010年   4167篇
  2009年   3849篇
  2008年   4058篇
  2007年   4268篇
  2006年   3748篇
  2005年   3293篇
  2004年   2654篇
  2003年   2353篇
  2002年   2027篇
  2001年   1937篇
  2000年   1576篇
  1999年   1435篇
  1998年   1218篇
  1997年   1180篇
  1996年   993篇
  1995年   981篇
  1994年   894篇
  1993年   712篇
  1992年   754篇
  1991年   630篇
  1990年   540篇
  1989年   448篇
  1988年   435篇
  1987年   411篇
  1986年   349篇
  1985年   351篇
  1984年   351篇
  1983年   228篇
  1982年   249篇
  1981年   167篇
  1980年   135篇
  1979年   136篇
  1978年   127篇
  1977年   59篇
  1976年   68篇
  1975年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.

Objective

Hypertonic saline (HTS) has potent immune and vascular effects. We assessed recipient pretreatment with HTS on allograft function in a porcine model of heart transplantation and hypothesized that HTS infusion would limit endothelial and left ventricular (LV) dysfunction following transplantation.

Methods

Heart transplants were performed after 6 hours of cold ischemic storage. Recipient pigs were randomized to treatment with or without HTS (7.5% NaCl) before cardiopulmonary bypass (CPB). Using a myograft apparatus, coronary artery endothelial-dependent (Edep) and -independent (Eind) relaxation was assessed. LV performance was determined using pressure-volume loop analysis. Pulmonary interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α expression was measured.

Results

Weaning from CPB and LV performance after transplantation were improved in HTS-treated animals. Successful weaning from CPB was greater in the HTS-treated hearts (8 of 8 vs 2 of 8; P < .05). Mean LV functional recovery was improved in the HTS-treated animals, as assessed by preload recruitable stroke work (65 ± 10% vs 27 ± 10%; P < .001) and end-systolic elastance (55 ± 7% vs 37 ± 4%; P < .001). Treatment with HTS resulted in improved Edep (mean maximum elastance [Emax], 56 ± 5% vs 37 ± 7%; P < .001) and Eind (mean Emax%, 77 ± 6% vs 52 ± 4%; P < .001) vasorelaxation compared with control. Pulmonary expression of IL-2, IL-6, and TNF-α increased following transplantation, whereas HTS therapy attenuated IL production (P < .001). Transplantation increased plasma TNF-α levels and LV TNF-α expression, whereas HTS prevented this up-regulation (P < .001).

Conclusions

Recipient HTS pretreatment preserves allograft vasomotor and LV function, and HTS therapy limits CPB-induced injury. HTS may be a novel recipient intervention to prevent graft dysfunction.  相似文献   
73.
74.

Objectives

The current study investigated the effects of two exercise interventions on cognitive function amongst breast cancer survivors.

Design

Pilot randomised-controlled trial.

Methods

Seventeen female cancer survivors (mean: 62.9 ± 7.8 years) were randomised into three groups: high-intensity interval training (HIIT, n = 6); moderate-intensity continuous training (MOD, n = 5); or wait-list control (CON, n = 6). The HIIT and MOD groups exercised on a cycle ergometer 3 days/week for 12-weeks. Primary outcomes were cognitive function assessments utilising CogState. Secondary outcomes were resting middle cerebral artery blood flow velocity, cerebrovascular reactivity and aerobic fitness (VO2peak). Data were analysed with General Linear Mixed Models and Cohen’s d effect sizes were calculated.

Results

All 17 participants who were randomised were available for follow-up analysis and adherence was similar for HIIT and MOD (78.7 ± 13.2% vs 79.4 ± 12.0%; p = 0.93). Although there were no significant differences in the cognitive and cerebrovascular outcomes, HIIT produced moderate to large positive effects in comparison to MOD and CON for outcomes including episodic memory, working memory, executive function, cerebral blood flow and cerebrovascular reactivity. HIIT significantly increased VO2peak by 19.3% (d = 1.28) and MOD had a non-significant 5.6% (d = 0.72) increase, compared to CON which had a 2.6% decrease.

Conclusions

This study provides preliminary evidence that HIIT may be an effective exercise intervention to improve cognitive performance, cerebrovascular function and aerobic fitness in breast cancer survivors. Considering the sample size is small, these results should be confirmed through larger clinical trials.  相似文献   
75.
目的 采用网络药理学阐明济脉通片多成分-多靶点-多途径的作用理念,为进一步研究济脉通片降压药效物质基础和机制提供一定理论参考。方法 通过TCMSP数据库,结合口服利用度(≥ 30%)和类药性分析(≥ 0.18)参数,筛选济脉通片的活性成分;通过Drugbank和TCMSP数据库进行靶点预测分析;通过GENCARD数据库筛选出高血压疾病相关基因;结合DAVID和KEGG数据库进行GO分析和通路分析;使用Cystoscope软件构建"化合物-靶点-作用通路"网络图。结果 经筛选后得到济脉通片的33个化合物,148个潜在靶基因并映射到了223条信号通路,其中31条信号通路与高血压的发生发展密切相关,其中AGE-RAGE signaling pathway in diabetic complications、PI3K-Akt signaling pathway、TNFsignaling pathway、Adrenergic signaling in cardiomyocytes和Focal adhesion为重要的通路枢纽。结论 济脉通片主要通过多成分、多靶点、多通路调节血管内皮功能、炎症反应、钙钠离子转运、糖脂代谢等参与血管舒张、改善炎症、调节机体代谢、调节离子转运等而产生降压作用。  相似文献   
76.
Renal Denervation for Treatment of Cardiac Arrhythmias . It has now been more than a quarter of a century since modulation of the sympathetic nervous system was proposed for the treatment of cardiac arrhythmias of different origins. But it has also been some time since some of the early surgical attempts have been abandoned. With the development of ablation techniques, however, new approaches and targets have been recently introduced that have revolutionized our way of thinking about sympathetic modulation. Renal nerve ablation technology is now being successfully used for the treatment of resistant hypertension, but the indication spectrum might broaden and new therapeutic options might arise in the near future. This review focuses on the possible impact of renal sympathetic system modulation on cardiac arrhythmias, the current evidence supporting this approach, and the ongoing trials of this method in electrophysiological laboratories. We will discuss the potential roles that sympathetic modulation may play in the future.  相似文献   
77.
78.
79.
《中国现代医生》2020,58(2):135-138+封三
目的探讨实时剪切波弹性成像在评估拉米夫定治疗乙肝纤维化临床疗效中的作用。方法选取2017年1月~2018年1月我院收治的80例乙肝纤维化患者,根据随机数字法分为对照组和观察组,每组40例。对照组采用常规治疗,观察组在对照组的基础上给予拉米夫定进行治疗,治疗6个月。比较两组治疗前后肝功能、肝纤维化指标,利用实时剪切波弹性成像评估两组治疗前后肝脏弹性模量值及肝穿刺活检情况,并进行比较。结果两组治疗后AST、ALT、TBIL水平均明显低于治疗前,差异有统计学意义(P0.05);观察组治疗后AST、ALT、TBIL水平均明显低于对照组,差异有统计学意义(P0.05);两组治疗后HA、LN、PⅢPN-P、CL-Ⅳ水平及杨氏弹性模量值均显著低于治疗前,差异有统计学意义(P0.05);观察组治疗后HA、LN、PⅢPN-P、CL-Ⅳ水平及杨氏弹性模量值均显著低于对照组,差异有统计学意义(P0.05);与治疗前相比,两组治疗后肝穿刺活检结果均有好转,尤其是汇管区、肝小叶内炎症及肝纤维化改善明显。结论实时剪切波弹性成像作为肝脏硬度定量检测的无创性技术,可用于拉米夫定治疗乙肝纤维化临床疗效评估的重要方法。  相似文献   
80.
《Journal of hand therapy》2020,33(4):528-539
Study DesignProspective longitudinal cohort study.IntroductionTraumatic brachial plexus injuries (BPIs) can be devastating and negatively impact daily function and quality of life. Occupational therapists play an important role in rehabilitation; however, studies identifying outcomes are lacking.PurposeThis study aims to describe outcomes including motor recovery, upper limb function, participation, pain, and quality of life for people receiving occupational therapy intervention.MethodsA convenience sample of English-speaking adults (n = 30) with a traumatic BPI, attending the clinic between December 1, 2014, to November 30, 2016, participated. Participants received occupational therapy focusing on sensorimotor retraining and activity-based rehabilitation. Data on active range of motion (goniometry), strength (Medical Research Council (MRC)), upper-limb function (UEFI15, QuickDASH), participation (PSFS), pain (Brief Pain Inventory), and quality of life (EQ-5D-3L) were collected at baseline, 3, 6, 9, and 12 months.ResultsElbow flexion strength showed significant improvement at all time-points, average increase 2.17 (MRC) (95% confidence interval: 1.29-3.04; P < .001) and mean final MRC grading 3.86 (standard error: 0.44). Significant improvements at 12 months were seen in: shoulder abduction strength and range, flexion strength and range, external rotation range; elbow extension strength and flexion range; thumb flexion and extension strength. Upper limb function (QuickDASH) showed significant improvement (mean change = 18.85; 95% confidence interval: 4.12-33.59; P = .02). Forearm protonation range and finger flexion strength were significantly worse. Remaining outcomes did not show significant improvement.ConclusionsOccupational therapy with surgical intervention can improve strength, range, and upper limb function with people following traumatic BPI. Further investigations into impact on participation, pain, and quality of life are required.  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