全文获取类型
收费全文 | 1749篇 |
免费 | 202篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 41篇 |
妇产科学 | 13篇 |
基础医学 | 580篇 |
口腔科学 | 107篇 |
临床医学 | 172篇 |
内科学 | 388篇 |
皮肤病学 | 41篇 |
神经病学 | 34篇 |
特种医学 | 16篇 |
外科学 | 121篇 |
综合类 | 138篇 |
预防医学 | 26篇 |
眼科学 | 16篇 |
药学 | 195篇 |
1篇 | |
中国医学 | 29篇 |
肿瘤学 | 81篇 |
出版年
2023年 | 44篇 |
2022年 | 49篇 |
2021年 | 59篇 |
2020年 | 55篇 |
2019年 | 56篇 |
2018年 | 56篇 |
2017年 | 44篇 |
2016年 | 65篇 |
2015年 | 61篇 |
2014年 | 64篇 |
2013年 | 109篇 |
2012年 | 53篇 |
2011年 | 66篇 |
2010年 | 49篇 |
2009年 | 61篇 |
2008年 | 67篇 |
2007年 | 73篇 |
2006年 | 66篇 |
2005年 | 69篇 |
2004年 | 76篇 |
2003年 | 49篇 |
2002年 | 61篇 |
2001年 | 72篇 |
2000年 | 56篇 |
1999年 | 49篇 |
1998年 | 53篇 |
1997年 | 44篇 |
1996年 | 45篇 |
1995年 | 48篇 |
1994年 | 36篇 |
1993年 | 31篇 |
1992年 | 36篇 |
1991年 | 26篇 |
1990年 | 20篇 |
1989年 | 19篇 |
1988年 | 14篇 |
1987年 | 15篇 |
1986年 | 9篇 |
1985年 | 15篇 |
1984年 | 17篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1977年 | 10篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1972年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有2005条查询结果,搜索用时 15 毫秒
31.
Acute lung injury (ALI) or its more severe form, the acute respiratory distress syndrome (ARDS), is a common, devastating clinical syndrome that affects both medical and surgical patients. The most common cause of ALI is sepsis. There is now well-documented evidence that pulmonary inflammation contributes to the devel-opment of ALI. Despite significant advances in our un-derstanding of pathophysiology and technologies in the supportive management, mortality from ALI remains excessive. C… 相似文献
32.
目的:研究角膜碱烧伤后基质损伤修复病程中多形核中性白细胞(PMNs)的浸润和基质金属蛋白酶-9(MMP-9)的表达的关系。
方法:建立25只家兔角膜碱烧伤模型,分别于伤后3、7、14、21、28d随机处死5只兔,裂隙灯下观察角膜病理修复情况,摘除角膜做病理切片,测定PMNs的浸润量值。免疫组化法测定MMP-9的表达。
结果:PMNs和MMP-9在角膜碱烧伤后的3d开始升高,14d上升达到最大峰值,之后逐渐降低,碱烧伤后角膜基质在第14d溃疡面积及深度最为严重。
结论:角膜碱烧伤病灶中PMNs和MMP-9的量值呈正相关,且角膜的病理损伤与PMNs的浸润和MMP-9的表达密切相关。 相似文献
33.
血小板激活因子及其拮抗剂银杏内酯B对大鼠心肌缺血再灌注损伤的影响(英文) 总被引:5,自引:0,他引:5
目的 探讨外源性血小板激活因子 (PAF)激活的多核形中性粒细胞 (PMN)是否具有低浓度氧自由基模拟缺血预适应 (IP)对缺血再灌注 (IR)所致心肌损伤的保护作用。方法 结扎冠脉左前降支 30min ,再灌注 3h制备大鼠心脏IR模型。以缺血前给予 2次 5min缺血 ,10min再灌注作为IP。实验分为6组 ,IR组、IR +PAF组和IR +银杏内酯B(GB、PAF拮抗剂 )组 ,分别于缺血前 2 5和 10miniv生理盐水、PAF(3μg·kg- 1)和GB (5mg·kg- 1) ;IP +IR组、IP +IR +PAF组和IP +IR +GB组分别于IP 2次 10min再灌注开始时iv相应药物。观察分析心功能、梗死面积、PMN计数、心肌髓过氧化物酶活性、TUNEL阳性细胞计数等指标。结果 给予PAF明显加重IR引起的心脏损伤、PMN浸润及凋亡的程度 ;GB对IR引起的心功能下降没有明显影响 ,但明显减少梗死面积、PMN浸润及凋亡细胞 ;PAF明显削弱IP的保护作用 ;GB对IP作用未见明显影响。结论 IR后PMN浸润可能是引起心肌细胞凋亡的一个重要原因 ;PAF激活PMN可能不具有模拟IP对IR所致心肌损伤的保护作用 ,反而取消IP的保护作用。 相似文献
34.
Kang-ni Feng Ping Meng Min Zhang Xiao-ling Zou Shuang Li Chu-qin Huang Ke-fang Lai Hong-tao Li Tian-tuo Zhang 《Allergy, asthma & immunology research》2022,14(5):505
PurposeNeutrophilic asthma is associated with asthma exacerbation, steroid insensitivity, and severe asthma. Interleukin (IL)-24 is overexpressed in asthma and is involved in the pathogenesis of several allergic inflammatory diseases. However, the role and specific mechanism of IL-24 in neutrophilic asthma are unclear. We aimed to elucidate the roles of IL-24 and IL-37 in neutrophilic asthma, the relationships with IL-17A and the mechanisms regulating neutrophilic asthma progression.MethodsPurified human neutrophils were isolated from healthy volunteers, and a cell coculture system was used to evaluate the function of IL-24 in epithelium-derived IL-17A-dependent neutrophil migration. IL-37 or a small interfering RNA (siRNA) targeting IL-24 was delivered intranasally to verify the effect in a murine model of house dust mite (HDM)/lipopolysaccharide (LPS)-induced neutrophilic asthma.ResultsIL-24 enhanced IL-17A production in bronchial epithelial cells via the STAT3 and ERK1/2 signaling pathways; this effect was reversed by exogenous IL-37. Anti-IL-17A monoclonal antibodies reduced neutrophil chemotaxis induced by IL-24-treated epithelial cells in vitro. Increased IL-24 and IL-17A expression in the airway epithelium was observed in HDM/LPS-induced neutrophilic asthma. IL-37 administration or IL-24 silencing attenuated neutrophilic asthma, reducing IL-17A levels and decreasing neutrophil airway infiltration, airway hyperresponsiveness, and goblet cell metaplasia. Silencing IL-24 inhibited T-helper 17 (Th17) immune responses, but not Th1 or Th2 immune responses, in the lungs of a neutrophilic asthma model.ConclusionsIL-24 aggravated neutrophilic airway inflammation by increasing epithelium-derived IL-17A production, which could be suppressed by IL-37. Targeting the IL-24/IL-17A signaling axis is a potential strategy, and IL-37 is a potential candidate agent for alleviating neutrophilic airway inflammation in asthma. 相似文献
35.
Anita Sapoznikov Yoav Gal Ron Alcalay Yentl Evgy Tamar Sabo Chanoch Kronman Reut Falach 《Toxins》2022,14(9)
Abrin is a highly toxic protein obtained from the seeds of the rosary pea plant Abrus precatorius, and it is closely related to ricin in terms of its structure and chemical properties. Both toxins inhibit ribosomal function, halt protein synthesis and lead to cellular death. The major clinical manifestations following pulmonary exposure to these toxins consist of severe lung inflammation and consequent respiratory insufficiency. Despite the high similarity between abrin and ricin in terms of disease progression, the ability to protect mice against these toxins by postexposure antibody-mediated treatment differs significantly, with a markedly higher level of protection achieved against abrin intoxication. In this study, we conducted an in-depth comparison between the kinetics of in vivo abrin and ricin intoxication in a murine model. The data demonstrated differential binding of abrin and ricin to the parenchymal cells of the lungs. Accordingly, toxin-mediated injury to the nonhematopoietic compartment was shown to be markedly lower in the case of abrin intoxication. Thus, profiling of alveolar epithelial cells demonstrated that although toxin-induced damage was restricted to alveolar epithelial type II cells following abrin intoxication, as previously reported for ricin, it was less pronounced. Furthermore, unlike following ricin intoxication, no direct damage was detected in the lung endothelial cell population following abrin exposure. Reduced impairment of intercellular junction molecules following abrin intoxication was detected as well. In contrast, similar damage to the endothelial surface glycocalyx layer was observed for the two toxins. We assume that the reduced damage to the lung stroma, which maintains a higher level of tissue integrity following pulmonary exposure to abrin compared to ricin, contributes to the high efficiency of the anti-abrin antibody treatment at late time points after exposure. 相似文献
36.
Mechanisms of hepatotoxicity. 总被引:22,自引:0,他引:22
Hartmut Jaeschke Gregory J Gores Arthur I Cederbaum Jack A Hinson Dominique Pessayre John J Lemasters 《Toxicological sciences》2002,65(2):166-176
This review addresses recent advances in specific mechanisms of hepatotoxicity. Because of its unique metabolism and relationship to the gastrointestinal tract, the liver is an important target of the toxicity of drugs, xenobiotics, and oxidative stress. In cholestatic disease, endogenously generated bile acids produce hepatocellular apoptosis by stimulating Fas translocation from the cytoplasm to the plasma membrane where self-aggregation occurs to trigger apoptosis. Kupffer cell activation and neutrophil infiltration extend toxic injury. Kupffer cells release reactive oxygen species (ROS), cytokines, and chemokines, which induce neutrophil extravasation and activation. The liver expresses many cytochrome P450 isoforms, including ethanol-induced CYP2E1. CYP2E1 generates ROS, activates many toxicologically important substrates, and may be the central pathway by which ethanol causes oxidative stress. In acetaminophen toxicity, nitric oxide (NO) scavenges superoxide to produce peroxynitrite, which then causes protein nitration and tissue injury. In inducible nitric oxide synthase (iNOS) knockout mice, nitration is prevented, but unscavenged superoxide production then causes toxic lipid peroxidation to occur instead. Microvesicular steatosis, nonalcoholic steatohepatitis (NASH), and cytolytic hepatitis involve mitochondrial dysfunction, including impairment of mitochondrial fatty acid beta-oxidation, inhibition of mitochondrial respiration, and damage to mitochondrial DNA. Induction of the mitochondrial permeability transition (MPT) is another mechanism causing mitochondrial failure, which can lead to necrosis from ATP depletion or caspase-dependent apoptosis if ATP depletion does not occur fully. Because of such diverse mechanisms, hepatotoxicity remains a major reason for drug withdrawal from pharmaceutical development and clinical use. 相似文献
37.
血必净对大鼠肝缺血-再灌注后急性肺损伤的保护作用 总被引:1,自引:0,他引:1
目的观察肝脏缺血-再灌注后急性肺损伤的发病机制及血必净对其的干预作用。方法将健康雄性Wistar大鼠90只随机分3组:假手术组(SOG组)30只,缺血再灌注组(I/R组)30只,血必净组(XBJ组)组30只。XBJ组术前3d经尾静脉注射血必净注射液5ml·kg-1·d-1。于再灌注6h、12h、24h各组分别随机选取10只大鼠进行标本检测:观察大鼠肺脏组织病理切片;取新鲜肺组织测定湿/干重比(W/D)、肺组织髓过氧化物酶(MPO)含量,取动脉血检测血气分析(PaO2)。结果XBJ组较I/R组在相同时相点的肺脏病理改变较轻,MPO含量显著降低(P<0.01);W/D显著降低(P<0.01);PaO2升高(P<0.05)。结论血必净注射液对肝脏缺血-再灌注后急性肺损伤具有保护作用,该作用与抑制中性粒细胞在肺内集聚、减少氧自由基的产生有关。 相似文献
38.
Lung cancer is the most common malignancy and the leading cause of cancer mortality worldwide; therefore, it is very important to understand the mechanism of its occurrence and progression. It has reported that inflammation is linked to the incidence of various malignancies. Neutrophils not only participate in the inflammatory response, but are also involved in the composition of the tumor microenvironment. Tumor-associated neutrophils (TANs) are infiltrating neutrophils in tumors that directly promote tumor development and progression. Moreover, they regulate the immune microenvironment and affect the therapeutic efficacy and prognosis of lung cancer. In the present review, the role of TANs in lung cancer development/progression and the underlying molecular signaling are evaluated, as well as the possibility of TANs as a potential therapeutic target for lung cancer intervention. 相似文献
39.
Rui Zhang Jin Chen Yanqin Xiong Lihong Wang Xinmei Huang Tiange Sun Bingbing Zha Yueyue Wu Cuili Yan Shufei Zang Qin Zhou Zhe Huang Jun Liu 《Journal of Diabetes》2022,14(7):442
BackgroundThis study aims to investigate the potential association of peripheral inflammatory blood cell parameters with the incidence and progression of chronic kidney disease (CKD) in patients with diabetes.MethodsThe cross‐sectional study included 1192 subjects with diabetes derived from one center. The cohort study included 2060 subjects with diabetes derived from another two centers followed up for 4 years. Logistic regression and Cox proportional hazards models were used to evaluate the association of peripheral inflammatory blood cell with CKD.ResultsIn the cross‐sectional study, neutrophil count performed best as an independent risk factor for CKD (odds ratio 2.556 [95% confidence interval 1.111, 5.879]) even after 1:1 case–control matching for age, gender, history of high blood pressure and duration of diabetes. Spline regression revealed a significant linear association of CKD incidence with continuous neutrophil count in excess of 3.6 × 109/L. In the cohort study, subjects were grouped based on tertile of neutrophil count and neutrophil‐to‐lymphocyte ratio. Cox regression analysis results showed that only neutrophil count was independently associated with CKD progression (the highest group vs. the lowest group, hazard ratio 2.293 [95% confidence interval 1.260, 4.171]) after fully adjusting for potential confounders. The cumulative incidence of CKD progression in patients with diabetes gradually increased with increasing neutrophil count (53 (7.7%) subjects in the lowest group vs. 60 (8.2%) in the middle group vs. 78 (12.2%) in the highest group).ConclusionsThis study suggested that neutrophil count is an independent risk factor for progression of CKD in patients with diabetes. 相似文献
40.