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   139802篇
  免费   7707篇
  国内免费   2679篇
耳鼻咽喉   579篇
儿科学   2578篇
妇产科学   1511篇
基础医学   14272篇
口腔科学   3933篇
临床医学   16059篇
内科学   24318篇
皮肤病学   1739篇
神经病学   8997篇
特种医学   4642篇
外国民族医学   5篇
外科学   18081篇
综合类   17324篇
现状与发展   7篇
一般理论   5篇
预防医学   9570篇
眼科学   1902篇
药学   11199篇
  95篇
中国医学   9819篇
肿瘤学   3553篇
  2023年   1518篇
  2022年   2087篇
  2021年   4706篇
  2020年   3793篇
  2019年   7183篇
  2018年   7406篇
  2017年   5651篇
  2016年   3338篇
  2015年   3309篇
  2014年   6230篇
  2013年   6700篇
  2012年   5427篇
  2011年   5911篇
  2010年   4824篇
  2009年   4174篇
  2008年   4314篇
  2007年   4462篇
  2006年   4039篇
  2005年   3617篇
  2004年   3161篇
  2003年   2981篇
  2002年   2541篇
  2001年   2512篇
  2000年   2053篇
  1999年   1824篇
  1998年   1523篇
  1997年   1630篇
  1996年   1317篇
  1995年   1336篇
  1994年   1226篇
  1993年   936篇
  1992年   926篇
  1991年   828篇
  1990年   656篇
  1989年   629篇
  1988年   610篇
  1987年   521篇
  1985年   3412篇
  1984年   3861篇
  1983年   3166篇
  1982年   3761篇
  1981年   3347篇
  1980年   2803篇
  1979年   2718篇
  1978年   2247篇
  1977年   1696篇
  1976年   2143篇
  1975年   1588篇
  1974年   1381篇
  1973年   1320篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
11.
12.
目的:观察血府逐瘀汤合温胆汤加减联合西药治疗高血压颈动脉硬化的效果。方法:选取2017年6月至2018年6月聊城市中医院收治的高血压颈动脉硬化患者92例作为研究对象,按照随机数字表法随机分为对照组与观察组,每组46例。对照组患者给予左旋氨氯地平+阿托伐他汀口服,观察组在对照组基础上加用血府逐瘀汤合温胆汤加减口服。观察患者血压、血脂控制情况,测定颈动脉内膜中层厚度(IMT)、斑块面积、血管皮内皮功能、血清蛋白酶分子水平。结果:与对照组比较,观察组治疗后的血压SBP、DBP及血脂TG、TC、LDL-C等指标更低(P<0.05);颈动脉粥样硬化斑块IMT厚度、斑块面积明显缩小(P<0.05),血管内皮功能指标ET-1、AngⅡ、TXB2水平明显降低,NO水平明显升高(P<0.05);血清CatK、MMP-9水平明显降低(P<0.05);观察组不良反应发生率8.70%明显低于对照组不良反应发生率21.74%(P<0.05)。结论:血府逐瘀汤合温胆汤加减联合西药更利于控制高血压颈动脉硬化患者的血压,调节脂质代谢,改善血管内皮功能,降低血清蛋白酶分子的含量,用药安全。  相似文献   
13.
随着社会的发展,人类生活方式的改变,高血压病越来越高发,具有低龄化趋势,代谢综合征常伴随发生,此种情况下的高血压往往是以舒张压升高为主,临床表现常与“亚健康”状态混淆,未能引起患者甚至部分医生的重视,然而事实上越来越多的科学研究证实舒张压高之危害十分明显,不容忽视。尽管现代医学对舒张压高的病因及病理机制有明确的阐述,但是暂时没有特效的药物。李延教授在治疗高血压病方面有着丰富的临床经验,临床中运用泽泻汤合温胆汤加减治疗舒张压高之眩晕,切中病机,加减灵活,屡有良效。文中从中医角度阐述舒张压高的病因病机,介绍李师辨病辨证思路,组方用药特点,附三则典型验案,另加个人心得体会,以期为舒张压高的有效治疗提供思路。  相似文献   
14.
目的观察脑电仿生电刺激小脑顶核对脑梗死后认知功能障碍的影响,并探讨其可能的机制。方法选取脑梗死后并发认知功能障碍患者50例,随机分成治疗组与对照组各25例。2组患者均接受康复治疗及认知功能训练,治疗组同时加用脑电仿生电刺激进行干预。2组患者分别于治疗前后应用蒙特利尔认知评估量表(MoCA)、简易精神状态量表(MMSE)评定认知功能变化,采用经颅多普勒超声(TCD)评估颅内动脉血流动力学改变。结果治疗后2组患者MoCA评分、MMSE评分均较组内治疗前提高(P<0.05),且治疗组评分明显较对照组高,差异有统计学意义(P<0.05)。治疗后2组患者颅内动脉血流动力学较组内治疗前改善(P<0.05),且治疗组较对照组改善更显著,差异有统计学意义(P<0.05)。治疗组与对照组总有效率分别为92%和64%,差异有统计学意义(P<0.05)。结论脑电仿生电刺激小脑顶核可有效改善脑梗死患者的认知功能,其可能机制是通过改善患者的脑循环进一步改善认知功能。  相似文献   
15.
16.

Background

It has been reported that particulate matter (PM) is associated with cardiovascular diseases (CVD) while metabolic syndrome is also an important risk factor for CVD. However, few studies have investigated the epidemiological association between PM and metabolic syndrome.

Objective

To investigate the association between one-year exposure to PM with an aerodynamic diameter <2.5?μm (PM2.5) and the risk of metabolic syndrome in Korean adults without CVD.

Methods

Exposure to PM2.5 was assessed using a Community Multiscale Air Quality (CMAQ) model. Metabolic syndrome was defined by National Cholesterol Education Program Adult Treatment Panel III. Andersen and Gill model with time-varying covariates, considering recurrent events, was used to investigate the association between one-year average PM2.5 and the risk of incident metabolic syndrome in 119,998 adults from the national health screening cohort provided by Korea National Health Insurance from 2009 to 2013.

Results

Higher risk of metabolic syndrome, waist-based obesity, hypertension, hypertriglyceridemia, low HDL cholesterol, and hyperglycemia were significantly associated with a 10-μg/m3 increase in PM2.5 [adjusted hazard ratio (HR): 1.070, 1.510, 1.499, 1.468, 1.627 and 1.380, respectively]. In addition, the risk of metabolic syndrome associated with PM2.5 exposure was significant in the consistently obese group (obese at baseline and endpoint).

Conclusion

Exposure to one-year average PM2.5 is associated with an increased risk of metabolic syndrome and its components in adults without CVD. These associations are particularly prominent in the consistently obese group (obese at baseline and endpoint). Our findings indicate that PM2.5 affects the onset of MS and its components which may lead to increase the risk of CVD.  相似文献   
17.
(+/?)3,4‐methylenedioxymethamphetamine (MDMA, “ecstasy”) is an abused psychostimulant that produces strong monoaminergic stimulation and whole‐body hyperthermia. MDMA‐induced thermogenesis involves activation of uncoupling proteins (UCPs), primarily a type specific to skeletal muscle (UCP‐3) and absent from the brain, although other UCP types are expressed in the brain (e.g. thalamus) and might contribute to thermogenesis. Since neuroimaging of brain temperature could provide insights into MDMA action, we measured spatial distributions of systemically administered MDMA‐induced temperature changes and dynamics in rat cortex and subcortex using a novel magnetic resonance method, Biosensor Imaging of Redundant Deviation in Shifts (BIRDS), with an exogenous temperature‐sensitive probe (thulium ion and macrocyclic chelate 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetramethyl‐1,4,7,10‐tetraacetate (DOTMA4?)). The MDMA‐induced temperature rise was greater in the cortex than in the subcortex (1.6 ± 0.4 °C versus 1.3 ± 0.4 °C) and occurred more rapidly (2.0 ± 0.2 °C/h versus 1.5 ± 0.2 °C/h). MDMA‐induced temperature changes and dynamics in the cortex and body were correlated, although the body temperature exceeded the cortex temperature before and after MDMA. Temperature, neuronal activity, and blood flow (CBF) were measured simultaneously in the cortex and subcortex (i.e. thalamus) to investigate possible differences of MDMA‐induced warming across brain regions. MDMA‐induced warming correlated with increases in neuronal activity and blood flow in the cortex, suggesting that the normal neurovascular response to increased neural activity was maintained. In contrast to the cortex, a biphasic relationship was seen in the subcortex (i.e. thalamus), with a decline in CBF as temperature and neural activity rose, transitioning to a rise in CBF for temperature above 37 °C, suggesting that MDMA affected CBF and neurovascular coupling differently in subcortical regions. Considering that MDMA effects on CBF and heat dissipation (as well as potential heat generation) may vary regionally, neuroprotection may require different cooling strategies. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
18.
Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.

Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.

Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.

Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion.  相似文献   
19.
《Neuro-Chirurgie》2022,68(4):414-425
Intraoperative monitoring of cerebral blood flow (CBF) has become an invaluable adjunct to vascular and oncological neurosurgery, reducing the risk of postoperative morbidity and mortality. Several technologies have been developed during the last two decades, including laser-based techniques, videomicroscopy, intraoperative MRI, indocyanine green angiography, and thermography. Although these technologies have been thoroughly studied and clinically applied outside the operative room, current practice lacks an optimal technology that perfectly fits the workflow within the neurosurgical operative room. The different available technologies have specific strengths but suffer several drawbacks, mainly including limited spatial and/or temporal resolution. An optimal CBF monitoring technology should meet particular criteria for intraoperative use: excellent spatial and temporal resolution, integration in the operative workflow, real-time quantitative monitoring, ease of use, and non-contact technique. We here review the main contemporary technologies for intraoperative CBF monitoring and their current and potential future applications in neurosurgery.  相似文献   
20.
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