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   1539篇
  免费   77篇
  国内免费   12篇
耳鼻咽喉   1篇
儿科学   3篇
妇产科学   2篇
基础医学   336篇
口腔科学   3篇
临床医学   54篇
内科学   45篇
神经病学   819篇
特种医学   18篇
外科学   72篇
综合类   74篇
预防医学   20篇
眼科学   23篇
药学   118篇
  1篇
中国医学   27篇
肿瘤学   12篇
  2024年   1篇
  2023年   20篇
  2022年   51篇
  2021年   84篇
  2020年   87篇
  2019年   49篇
  2018年   27篇
  2017年   38篇
  2016年   89篇
  2015年   63篇
  2014年   82篇
  2013年   79篇
  2012年   81篇
  2011年   94篇
  2010年   71篇
  2009年   88篇
  2008年   83篇
  2007年   73篇
  2006年   59篇
  2005年   44篇
  2004年   26篇
  2003年   25篇
  2002年   17篇
  2001年   32篇
  2000年   34篇
  1999年   22篇
  1998年   24篇
  1997年   27篇
  1996年   15篇
  1995年   34篇
  1994年   22篇
  1993年   18篇
  1992年   21篇
  1991年   11篇
  1990年   13篇
  1989年   6篇
  1988年   2篇
  1987年   4篇
  1986年   1篇
  1985年   2篇
  1978年   1篇
  1974年   2篇
  1973年   4篇
  1972年   1篇
  1971年   1篇
排序方式: 共有1628条查询结果,搜索用时 15 毫秒
1.
目的 探讨小胶质细胞在癫痫中的激活特点及其在癫痫中的作用。方法 将12只Sprague-Dawley(SD)雄性大鼠随机分为对照组和癫痫组,每组各6只; 癫痫组采用氯化锂-匹鲁卡品腹腔注射的方法造模,对照组给予等量生理盐水; 癫痫发作4 d后取大鼠脑组织,采用蛋白质免疫印迹法(Western blot)和免疫组化的方法研究各组电离钙结合适配器分子-1(Ionized calcium binding adaptor molecule 1,Iba1)+小胶质细胞的表达情况。结果 与对照组大鼠模型相比,癫痫组大鼠丘脑皮层环路Iba1的表达增加,小胶质细胞的激活程度增加,且小胶质细胞特异性地在梨状皮质、丘脑室旁核、丘脑外侧背核,腹外侧部分以及腹内侧丘脑核增生。结论 癫痫发作后小胶质细胞的激活和增生存在着明显的脑区选择性,抑制丘脑皮层环路小胶质细胞的激活有望成为癫痫治疗的靶点。  相似文献   
2.
目的 银椴苷(Tiliroside,Tle)是一种天然产物,存在于结香花(Edgeworthia chrysantha Lindl.)、金英(Galphimia gracilis)、和Phlomoides spectabilis等生物体中。本文主要探讨Tle对脂多糖(lipopolysaccharide,LPS)激活的原代小胶质细胞的M1/M2极化的转化作用及其抑制神经炎症反应的影响。方法 MTT检测各浓度Tle对LPS激活的原代小胶质细胞活性的影响;Griess试剂检测LPS激活的原代小胶质细胞的一氧化氮(Nitric oxide,NO)产物生成量的影响;ELISA法检测Tle对LPS激活的原代小胶质细胞的肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、白细胞介素-6(Interleukin-6,IL-6)蛋白水平的影响;qRT-PCR检测Tle对LPS激活的原代小胶质细胞的精氨酸酶-1(Arginase-1,Arg-1)和胰岛素生长因子-1(Insulin growth factor-1,IGF-1)的mRNA表达水平。结果 Tle(0-80 μmol·L-1)对LPS激活的原代小胶质细胞活性没有明显影响;Tle显著降低LPS激活的原代小胶质细胞亚硝酸盐的含量,并对炎症因子IL-6、TNF-α蛋白水平有显著抑制作用,同时显著提高抗炎因子Arg-1和IGF-1的mRNA水平。结论 Tle能够通过促进LPS激活的原代小胶质细胞M1型向M2型转化从而抑制神经炎症反应,因此Tle具有一定的神经保护作用。  相似文献   
3.
4.
Inhibition of phosphodiesterase-4 (PDE4) produces robust anti-inflammatory and antidepressant-like effects in multiple animal models. However, the detailed mechanisms have not been well studied. Receptor for advanced glycation endproducts (RAGE) and inflammasome activation are implicated in the etiology of depression. Here, we aimed to investigate the involvement of RAGE and nucleotide-binding domain (NOD)–like receptor protein 3 (NLRP3) inflammasome in the antidepressant-like effects of PDE4 inhibition in mice. We found that inhibition of PDE4 by roflupram (ROF, 0.5, and 1.0 mg/kg, i.g.) exerted antidepressant-like effects in mice subjected to chronic unpredictable mild stress (CUMS). Simultaneously, ROF inhibited CUMS-induced microglial activation and restored the morphology of microglial cells in the hippocampus, as evidenced by reduced total process length, area, volume, number of branching points, number of terminal points and total sholl intersections of microglia. ROF also decreased the expression of ionized calcium-binding adapter molecule-1 and the level of interleukin-1β. Western blot analysis showed that PDE4 inhibition suppressed the high-mobility group box 1 protein (HMGB1)/RAGE signaling pathway, as the levels of HMGB1, RAGE, toll-like receptor 4, phosphorylated p38 mitogen-activated protein kinase, and nuclear factor κ-B were decreased in both hippocampus and cortex in mice after treatment with ROF. Moreover, ROF also attenuated the protein levels of NLRP3, the apoptosis-associated speck-like protein containing (ASC), and cysteine-requiring aspartate protease-1 (Caspase-1), which are key proteins in the NLRP3-mediated inflammasome signaling pathway. In summary, these results demonstrate that the down-regulation of HMGB1/RAGE signaling pathway and inflammasome suppression possibly contribute to the antidepressant-like effects of PDE4 inhibitors. And, ROF has potential as a candidate drug in the treatment of depression.  相似文献   
5.
Due to overexposure, manganese (Mn) accumulation in the brain can trigger the inhibition of glutathione synthesis and lead to increased generation of reactive oxygen species (ROS) and oxidative stress. D-Ribose-L-Cysteine (RibCys) has been demonstrated to effectively support glutathione synthesis to scavenge ROS and protect cells from oxidative damage. In the present study, we examined the effects of RibCys on weight changes, cognitive and motor associated activities, oxidative stress markers, striatal and cortical histology, and microglia activation following Mn exposure. Rats were exposed to either saline, Mn or/and RibCys for two weeks. The Mn exposed rats received RibCys either as pre-, co-, or post-treatments. Mn caused a significant decrease in weight, memory and motor activities, increased lactate dehydrogenase level, overexpression of IBA1 reflecting microglia activation, and distortion of the neuronal cytoarchitecture of the striatum and motor cortex, respectively. Interventions with RibCys mitigated Mn-induced neurotoxic events. Our novel study demonstrates that RibCys effectively ameliorates the neurotoxicity following Mn treatment and maybe a therapeutic strategy against the neurological consequences of Mn overexposurec  相似文献   
6.
慢性牙周炎属于慢性感染性疾病,与多种全身疾病存在双向关系。帕金森病是一种常见的神经退行性变性疾病,炎症反应在其进展中起到一定作用。近年来,大量研究提示慢性牙周炎与帕金森病等神经退行性变性疾病之间存在潜在联系,帕金森病患者牙周状况较差,其口腔菌群组成与健康人群存在差异;与此同时,慢性牙周炎患者罹患帕金森病的风险更高,定期牙周治疗可能在一定程度上降低该风险。慢性牙周炎与帕金森病的相互作用机制尚未明确,部分研究认为帕金森病患者可能由于运动及非运动症状,无法有效维护口腔卫生,增加牙周炎患病风险;小胶质细胞介导的神经炎症则可能是慢性牙周炎影响帕金森病的关键,牙周致病菌及炎症介质或可通过多种途径进入大脑并激活小胶质细胞,最终影响帕金森病的发生发展。本文就慢性牙周炎与帕金森病相关性及可能的交互作用机制的最新研究进展作一综述,以期为进一步探讨两者相互影响的研究提供思路。  相似文献   
7.
目的研究阿司匹林对Poly-IC诱导小胶质细胞激活的影响及其机制。方法通过体外培养小鼠小胶质细胞BV2细胞株,建立Poly-IC刺激诱导小胶质细胞免疫激活模型。本研究分为对照组(不做处理)、模型组(Poly-IC 10μg/ml)、高剂量阿司匹林组(1 mmol/L阿司匹林)、低剂量阿司匹林组(0.1 mmol/L阿司匹林)、高剂量阿司匹林预处理组(Poly-IC 10μg/ml+1 mmol/L阿司匹林)、低剂量阿司匹林预处理组(Poly-IC 10μg/ml+0.1 mmol/L阿司匹林)。应用细胞免疫荧光法检测小胶质细胞吞噬能力﹑活性氧﹑Iba1蛋白表达,RT-qPCR法检测各组小胶质细胞炎症因子IL-1β﹑IL-6﹑IL-10﹑TNF-α﹑COX-2的mRNA表达。结果与对照组相比较,模型组中小胶质细胞形态发生改变,吞噬能力增强,活性氧产生增加,Iba1蛋白表达下降。且模型组中IL-1β(20.55±1.92)﹑IL-6(63.98±7.83)﹑TNF-α(16.84±3.19)﹑COX-2(6.78±0.42)的mRNA表达较对照组IL-1β(1.01±0.14)﹑IL-6(0.95±0.17)﹑TNF-α(1.22±0.38)﹑COX-2(0.87±0.11)显著增加(t=26.14,10.22,17.06,37.07;均P<0.01)。经阿司匹林预处理的小胶质细胞吞噬能力较模型组减弱,活性氧产生较模型组降低,且Iba1蛋白表达较模型组有一定恢复。高剂量阿司匹林预处理组促炎因子IL-1β(9.95±0.52)﹑IL-6(39.64±6.89)﹑TNF-α(1.57±0.42)﹑COX-2(2.47±0.14)的mRNA表达较模型组明显降低(t=14.18,3.69,16.68,27.03;均P<0.01)。结论阿司匹林对Poly-IC诱导小胶质细胞激活有抑制作用,其机制可能与阿司匹林抑制胶质细胞炎性因子的表达有关。  相似文献   
8.
A high salt diet (HSD) is among the most important risk factors for many diseases. One mechanism by which HSD aggravates cerebral ischemic injury is independent of blood pressure changes. The direct role of HSD in inflammation after cerebral ischemia is unclear. In this research, after twenty-one days of being fed a high salt diet, permanent focal ischemia was induced in mice via operation. At 12 h and 1, 3 and 5 days postischemia, the effects of HSD on the lesion volume, microglia polarization, aldose reductase (AR) expression, and inflammatory processes were analyzed. We report that in mice, surplus dietary salt promotes inflammation and increases the activation of classical lipopolysaccharide (LPS)-induced microglia/macrophages (M1). This effect depends on the expression of the AR protein in activated microglia after permanent middle cerebral artery ligation (pMCAL) in HSD mice. The administration of either the AR inhibitor Epalrestat or a p38-neutralizing antibody blocked the polarization of microglia and alleviated stroke injury.In conclusion, HSD promotes polarization in pro-inflammatory M1 microglia by upregulating the expression of the AR protein via p38/MAPK, thereby exacerbating the development of ischemia stroke.  相似文献   
9.
目的: 研究黄芪甲苷对大鼠脑缺血后小胶质细胞/巨噬细胞M1/M2极化及炎症反应的影响。方法: 将48只大鼠随机分为手术对照组、模型对照组和黄芪甲苷组。采用线栓法建立大鼠大脑中动脉阻塞模型。黄芪甲苷组造模后即刻腹腔注射黄芪甲苷(40 mg/kg),随后1次/d,连续给药3 d。各组术后第1、3天采用改良的神经损伤严重程度评分(mNSS)和角试验进行神经功能评价;术后第3天采用2,3,5-氯化三苯基四氮唑染料(TTC)染色检测脑梗死体积;实时逆转录PCR检测M1型小胶质细胞/巨噬细胞表面标志物CD86、诱导型一氧化氮合酶(iNOS)和促炎因子TNF-α、IL-1β、IL-6的mRNA表达,以及M2型小胶质细胞/巨噬细胞表面标志物CD206、精氨酸酶1(Arg-1)、类几丁质酶3样分子1/2(YM1/2)及抗炎因子IL-10、TGF-β的mRNA表达;免疫荧光双标记法检测脑缺血周边区CD16/32/Iba1和CD206/Iba1的表达。结果: 与模型对照组比较,黄芪甲苷组mNSS分值降低、右转次数减少(P < 0.05或P < 0.01),脑梗死体积减小(P < 0.01),M1型小胶质细胞/巨噬细胞标志物CD86、iNOS、TNF-α、IL-1β和IL-6的mRNA表达下调(均P < 0.01),M2型小胶质细胞/巨噬细胞标志物CD206、Arg-1、YM1/2、IL-10和TGF-β的mRNA表达上调(均P < 0.01),脑缺血区CD16/32+/Iba1+细胞数量减少(P < 0.05),CD206+/Iba1+细胞数量增加(P < 0.01)。结论: 黄芪甲苷对大鼠脑缺血损伤有保护作用,可能与促进小胶质细胞/巨噬细胞从M1型向M2型转化、抑制炎症反应有关。  相似文献   
10.
Major depressive disorder is a debilitating disorder affecting millions of people each year. Brain-derived neurotrophic factor (BDNF) and inflammation are two prominent biologic risk factors in the pathogenesis of depression that have received considerable attention. Many clinical and animal studies have highlighted associations between low levels of BDNF or high levels of inflammatory markers and the development of behavioral symptoms of depression. However, less is known about potential interaction between BDNF and inflammation, particularly within the central nervous system. Emerging evidence suggests that there is bidirectional regulation between these factors with important implications for the development of depressive symptoms and anti-depressant response. Elevated levels of inflammatory mediators have been shown to reduce expression of BDNF, and BDNF may play an important negative regulatory role on inflammation within the brain. Understanding this interaction more fully within the context of neuropsychiatric disease is important for both developing a fuller understanding of biological pathogenesis of depression and for identifying novel therapeutic opportunities. Here we review these two prominent risk factors for depression with a particular focus on pathogenic implications of their interaction.  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