首页 | 官方网站   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   30682篇
  免费   3978篇
  国内免费   1125篇
医药卫生   35785篇
  2024年   279篇
  2023年   1093篇
  2022年   1982篇
  2021年   2545篇
  2020年   2012篇
  2019年   1678篇
  2018年   1433篇
  2017年   1430篇
  2016年   1415篇
  2015年   1561篇
  2014年   1934篇
  2013年   3025篇
  2012年   1561篇
  2011年   1673篇
  2010年   1431篇
  2009年   1324篇
  2008年   1400篇
  2007年   1305篇
  2006年   1130篇
  2005年   918篇
  2004年   801篇
  2003年   626篇
  2002年   522篇
  2001年   386篇
  2000年   316篇
  1999年   315篇
  1998年   275篇
  1997年   224篇
  1996年   198篇
  1995年   175篇
  1994年   126篇
  1993年   126篇
  1992年   84篇
  1991年   68篇
  1990年   45篇
  1989年   47篇
  1988年   46篇
  1987年   28篇
  1986年   34篇
  1985年   38篇
  1984年   35篇
  1983年   26篇
  1982年   20篇
  1981年   24篇
  1980年   20篇
  1979年   13篇
  1978年   14篇
  1977年   9篇
  1976年   8篇
  1975年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
香菇多糖抗炎作用的实验研究   总被引:5,自引:0,他引:5  
目的:研究香菇多糖的抗炎作用。方法:用二甲苯所致小鼠耳肿胀、鸡蛋清所致小鼠足跖肿胀等急性炎症以及滤纸片诱发小鼠肉芽组织增生所致小鼠慢性炎症模型进行试验。结果:香菇多糖能抑制二甲苯所致的小鼠耳肿、鸡蛋清所致小鼠足跖肿胀;与此同时对滤纸片诱发小鼠肉芽组织增生形成有抑制作用。结论:香菇多糖具有一定抑制急慢性炎症反应作用。其抗炎作用的机制,值得进一步研究。  相似文献   
4.
BACKGROUND: Levels of an immunoregulatory and anti-inflammatory cytokine IL-10 are reduced in asthmatic airways, potentially contributing to more intense inflammation. Triamcinolone has anti-inflammatory properties and the anti-inflammatory effects of montelukast and formoterol have been discussed. OBJECTIVE: The purpose of this study was to define the effect of treatment with triamcinolone, montelukast and formoterol on the serum level of IL-10, eosinophil blood counts, eosinophil cationic response (ECP) and clinical parameters (symptom score, FEV1 and PC20H) in children with moderate asthma. METHODS: An 8-week, placebo-controlled and randomized, double-blind trial was carried out. The subjects were 91 children with moderate atopic asthma who were allergic to dust mite. Patients were randomly allocated to receive 400 microg triamcinolone (n = 19), 5 or 10 mg (according to age) montelukast (n = 18), 24 microg formoterol (n = 18) or placebo (n = 36). RESULTS: Seventy-nine children completed the study. After treatment with triamcinolone and montelukast the level of IL-10 in blood serum significantly increased, eosinophil blood counts and ECP levels significantly decreased and all clinical parameters improved; treatment with formoterol had no effect on IL-10 level, eosinophil blood counts in serum and bronchial hyper-reactivity; ECP level significantly decreased after treatment and asthma symptoms and FEV1 improved significantly. Mean IL-10 levels in serum before and after treatment with triamcinolone were 7.23 pg/mL with 95% CI, 6.74 -7.72% and 14.24 pg/mL with 95% CI, 11.6-16.88%, respectively (P < 0.001); with montelukast they were 6.59 pg/mL with 95% CI, 6.26-7.23% and 10.94 pg/mL with 95% CI, 8.24-12.65%, respectively (P < 0.002); with formoterol they were 7.06 pg/mL with 95% CI, 6.61-7.52% and 7.04 pg/mL with 95% CI, 6.15-7.93%. We found statistically significant correlations between serum level of IL-10 and serum level of ECP after treatment with triamcinolone and montelukast. CONCLUSION: This study demonstrates that one possible way by which triamcinolone and montelukast contribute to inhibition of inflammation is by increasing IL-10 levels.  相似文献   
5.
6.
In this review, we critically evaluate the evidence for local IgE production in allergic rhinitis mucosa and the concept of local allergy in non-atopic idiopathic rhinitis. Significantly, fewer studies have focused on the disease pathways associated with non-allergic rhinitis compared with their allergic counterparts. Recently, there's been a revival of the hypothesis concerning the existence of local tissue-specific allergic disease confined to the nasal mucosa of some systemically non-atopic rhinitis subjects. Providing the evidence for local mucosal IgE production in allergic rhinitis is a pre-requisite to reviewing its existence in non-allergic rhinitis. In addition, practical and theoretical approaches useful in the detection of allergy in non-allergic rhinitis will be discussed. Furthermore, successful therapeutic regimens used in the treatment of non-allergic rhinitis will be examined as these could provide an insight into the underlying pathophysiology of this common but poorly understood disease.  相似文献   
7.
BACKGROUND: Stress can aggravate the allergic inflammation, but determinants of disturbed immune regulation are largely unknown. OBJECTIVE: To determine systemic immunological, local inflammatory and functional airway responses to stress in healthy and atopic individuals. METHODS: Forty-one undergraduate students, 22 with allergy of whom 16 had asthma, and 19 healthy controls, were studied in a low-stress period and in association with a large exam. Subjects completed questionnaires on stress and health behaviours, underwent lung function tests, bronchial methacholine challenge, measurements of exhaled nitric oxide and urine cortisol. Blood cells were phenotyped, and cytokines from mononuclear blood cells were analysed. RESULTS: Perceived stress and anxiety increased in both groups during the exam period while cortisol increased only in the atopy group. Cytokine production decreased broadly in response to stress in both groups, which was paralleled by an increase in the proportion of regulatory T cells (CD4(+)CD45RO(+)CD25(bright)). Interestingly, atopic individuals, but not controls, reacted with a decreased T-helper type 1/T-helper type 2 (Th1/Th2) ratio and a decrease in natural killer (NK) cell numbers in response to stress. In control subjects only, exhaled nitric oxide decreased and forced expiratory volume in one second increased during stress. CONCLUSION: Atopic and non-atopic subjects shared some immune changes in response to stress, such as a dramatic decline in cytokines and an increase in the number of regulatory T cells in peripheral blood. However, other stress-induced immune changes were unique to atopic individuals, such as a skewed Th1/Th2 ratio and reduced NK cell numbers, indicating that some pathogenic mechanisms in atopics may be more strongly affected by stress than others.  相似文献   
8.
Summary During pacemaker implantation in a patient with permanent atrial fibrillation, it remained impossible to advance a passive fixation lead with fins through the right atrium. However, a lead with a retractable screw easily passed the right atrium and was positioned in the right ventricle. Transesophageal echocardiography revealed an extensive net–like perforated Eustachian valve within the right atrium that had caused entrapment of the anchor fins during lead implantation. Remnants of embryonal structures within the right atrium should be considered a rare possible barrier during pacemaker implantation.  相似文献   
9.
无线网络技术在医学仪器中的应用   总被引:1,自引:0,他引:1  
简要介绍无线网络技术的原理、特点及其在医学仪器中的应用.  相似文献   
10.
李艳芳  邱龄 《当代医学》2010,16(3):9-11
目的探讨单独应用阿托伐他汀与联合应用阿托伐他汀和匹格列酮对高危心血管人群颈动脉内膜中层厚度(CIMT)、高敏C反应蛋白(hs-CRP)、基质金属蛋白酶-9(MMP-9)、脂联素及脂质状况的影响。方法90名有心血管危险因素的患者被随机分为两组:单独应用阿托伐他汀治疗组、联合应用阿托伐他汀和匹格列酮治疗组,分别检测两组患者治疗前及治疗六个月后的CIMT、hs-CRP、脂联素、MMP-9的血浆水平及检测血脂水平。结果单独应用阿托伐他汀及联合应用阿托伐他汀和匹格列酮均显示CIMT的显著降低(P〈0.001),无组间差异(P〉0.05)。两组的MMP-9在治疗后均较治疗前降低,有统计学意义(P〈0.05),但组间无统计学差异(P〉0.05)。两组对h-CRP、脂联素及血脂水平均有有意义的影响,组间有统计学差异,联合用药组提示影响更显著(P〈0.05)。联合用药组血浆脂联素水平明显升高而单独应用阿托伐他汀组未被观察到。结论阿托伐他汀明显改善CIMT,联合应用阿托伐他汀和匹格列酮对脂质状况和炎症因子有额外的影响。  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-23

京公网安备 11010802026262号