全文获取类型
收费全文 | 5923篇 |
免费 | 353篇 |
国内免费 | 188篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 116篇 |
妇产科学 | 186篇 |
基础医学 | 1530篇 |
口腔科学 | 130篇 |
临床医学 | 420篇 |
内科学 | 1156篇 |
皮肤病学 | 170篇 |
神经病学 | 576篇 |
特种医学 | 50篇 |
外科学 | 554篇 |
综合类 | 469篇 |
预防医学 | 281篇 |
眼科学 | 57篇 |
药学 | 408篇 |
1篇 | |
中国医学 | 124篇 |
肿瘤学 | 187篇 |
出版年
2024年 | 2篇 |
2023年 | 33篇 |
2022年 | 80篇 |
2021年 | 144篇 |
2020年 | 153篇 |
2019年 | 121篇 |
2018年 | 142篇 |
2017年 | 165篇 |
2016年 | 243篇 |
2015年 | 225篇 |
2014年 | 383篇 |
2013年 | 488篇 |
2012年 | 303篇 |
2011年 | 445篇 |
2010年 | 325篇 |
2009年 | 384篇 |
2008年 | 425篇 |
2007年 | 357篇 |
2006年 | 334篇 |
2005年 | 291篇 |
2004年 | 268篇 |
2003年 | 195篇 |
2002年 | 153篇 |
2001年 | 130篇 |
2000年 | 111篇 |
1999年 | 77篇 |
1998年 | 90篇 |
1997年 | 76篇 |
1996年 | 83篇 |
1995年 | 77篇 |
1994年 | 58篇 |
1993年 | 47篇 |
1992年 | 30篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 1篇 |
排序方式: 共有6464条查询结果,搜索用时 156 毫秒
41.
连续肾替代治疗对严重烧伤脓毒症患者血浆内毒素和细胞因子水平的影响 总被引:25,自引:3,他引:22
目的 分析连续肾替代治疗 (continuousrenalreplacementtherapy,CRRT)对严重烧伤脓毒症患者血浆内毒素和细胞因子水平的影响。 方法 对 10例应用CRRT及 10例应用常规疗法治疗的严重烧伤脓毒症患者血浆内毒素和细胞因子 (TNFα、IL 1β、IL 6、IL 8)浓度变化进行比较分析。 结果 严重烧伤脓毒症患者应用CRRT后血浆内毒素、细胞因子浓度较治疗前明显下降 ,其下降速度与常规治疗组比较差异有非常显著性意义 (P <0 .0 1)。 结论 严重烧伤脓毒症患者应用CRRT能有效降低血浆内毒素和细胞因子浓度 相似文献
42.
Astrocytes contribute to the immunocompetence of the central nervous system (CNS) via their expression of class II major histocompatibility complex (MHC) antigens and the production of inflammatory cytokines such as interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). Of these cytokines, IL-6 is of particular interest because one of its many immune and inflammatory actions is the promotion of immunoglobulin synthesis, and it is thought that IL-6 expression within the brain exacerbates autoimmune diseases of the CNS, which are marked by local immunoglobulin production. Several stimuli induce astrocyte IL-6 expression, including such inducible endogenous factors as IL-1β and TNF-α. We have investigated the possibility that a constitutively present endogenous factor, the neurotransmitter norepinephrine (NE), can induce astrocyte IL-6 production. We report that NE induces both IL-6 mRNA and protein in primary neonatal rat astrocytes, with optimal induction at 10 μM. IL-6 protein induction by NE is comparable to that seen with IL-1β or TNF-α, and NE synergizes with these cytokines for a ten-fold enhanced effect. In contrast to astrocytes, microglia are relatively unresponsive to NE, IL-1β and TNF-α for IL-6 production. Experiments with the β-adrenergic receptor agonist isoproterenol, and α and β-adrenergic receptor antagonists (propranolol, phentolamine, atenolol, and yohimbine) indicate that β2 and α1-adrenergic receptors are involved in NE induction of astrocyte IL-6 expression. These results help to further the understanding of neuron-glial interactions, and the role of astrocytes and adrenergic activity in immune responses within the CNS. 相似文献
43.
背景 调节性B淋巴细胞(Breg)是一类具有负向免疫调节作用的细胞,在多种自身免疫性疾病中表达异常,视神经脊髓炎谱系疾病(NMOSD)系自身免疫性疾病,目前关于Breg在NMOSD患者外周血中的表达和意义的研究较少。目的 研究Breg在NMOSD患者外周血中的表达和意义。方法 选取2019年6月—2021年12月新疆医科大学第一附属医院神经内科收治的NMOSD患者55例作为NMOSD组,选取同期本院体检正常的健康志愿者50例作为对照组。运用流式细胞仪检测两组研究对象外周血中CD19+CD24hiCD38hi Breg、CD19+CD24hiCD27+Breg的表达。采用酶联免疫吸附测定(ELISA)法检测和比较两组研究对象血清中白介素10(IL-10)、白介素35(IL-35)和转化生长因子β1(TGF-β1)的水平。结果 NMOSD组患者CD19+CD24hiCD38hi Breg、CD1... 相似文献
44.
Autoimmune hepatitis type 1 and primary biliary cirrhosis have distinct bone marrow cytokine production 总被引:3,自引:0,他引:3
Zachou K Rigopoulou EI Tsikrikoni A Alexandrakis MG Passam F Kyriakou DS Stathakis NE Dalekos GN 《Journal of autoimmunity》2005,25(4):389-288
We have recently reported differences in the hematopoiesis between autoimmune hepatitis type 1 (AIH-1) and primary biliary cirrhosis (PBC). In view of the notion that cytokines are regulators of hematopoiesis, we investigated in our tertiary center the cytokine production in the bone marrow (BM) of the same consecutive cohort of patients (13 AIH-1, 13 PBC, 10 healthy and 7 patients with cirrhosis due to chronic hepatitis B). Interferon-gamma (IFN-gamma), interleukin-4 (IL-4), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta) were determined in the supernatants of long-term BM cultures by ELISAs. IL-4, TNF-alpha and TGF-beta were found significantly increased in the BM of PBC patients compared to AIH-1 and both control groups. AIH-1 patients had significantly higher BM IL-10 compared to PBC patients and higher IL-10, IL-4 and TNF-alpha compared to controls. BM IFN-gamma was significantly higher in PBC and AIH-1 patients compared to controls. In AIH-1 patients, IL-10 was positively correlated with CD34+, CD34+/CD38- and CD34+/CD38+ cell proportions. In conclusion, the BM cytokine microenvironment of PBC and AIH-1 patients differs significantly compared to that of healthy individuals and cirrhotic patients of non-autoimmune etiology. Differences were also found between patients with PBC and AH-1. The implication of BM in the pathogenesis of autoimmune liver diseases is possible and needs further investigation. 相似文献
45.
46.
Rojas OL González AM González R Pérez-Schael I Greenberg HB Franco MA Angel J 《Virology》2003,314(2):671-679
Using an intracellular cytokine assay, we recently showed that the frequencies of rotavirus (RV)-specific CD4(+) and CD8(+) T cells secreting INFgamma, circulating in RV infected and healthy adults, are very low compared to the frequencies of circulating cytomegalovirus (CMV) reactive T cells in comparable individuals. In children with acute RV infection, these T cells were barely or not detectable. In the present study, an ELISPOT assay enabled detection of circulating RV-specific INFgamma-secreting cells in children with RV diarrhea but not in children with non-RV diarrhea without evidence of a previous RV infection. Using microbead-enriched CD4(+) and CD8(+) T cell subsets, IFNgamma-secreting RV-specific CD8(+) but not CD4(+) T cells were detected in recently infected children. Using the same approach, both CD4(+) and CD8(+) RV-specific T cells were detected in healthy adults. Furthermore, stimulation of purified subsets of PBMC that express lymphocyte homing receptors demonstrated that RV-specific INFgamma-secreting CD4(+) T cells from adult volunteers preferentially express the intestinal homing receptor alpha4beta7, but not the peripheral lymph node homing receptor L-selectin. In contrast, CMV-specific INFgamma-secreting CD4(+) T cells preferentially express L-selectin but not alpha4beta7. These results suggest that the expression of homing receptors on virus-specific T cells depends on the organ where these cells were originally stimulated and that their capacity to secrete INFgamma is independent of the expression of these homing receptors. 相似文献
47.
目的 探讨肾上腺素(Epi)对内毒素(脂多糖,LPS)致大鼠炎症性肝损害的保护作用及其作用机制。方法 50只SD大鼠随机分为5组(每组各10只):对照组:静脉滴注生理盐水2.4mL·kg^-1·h^-1;LPS组:静脉注射LPS6mg·kg^-1后,静脉滴注生理盐水2.4mL·kg^-1·h^-1;低、中和高剂量Epi组:静脉注射LPS6mg·kg^-1后,分别静脉滴注Epi0.12、0.3和0.6μg·kg^-1·min^-1。在LPS注射前、注射后2和6h3个时点取血,检测血清ALT、AST、TNF-α、IL-1β和IL-10水平,并在6h时点观察肝脏的组织病理学改变。结果 LPS组注射LPS后2、6h血清AST和ALT水平较对照组显著升高。同时血清TNF-α、IL-1β和IL-10水平亦较对照组显著升高(P〈0.05)。病理检查结果示:LPS组肝窦扩张、充血,局灶性肝细胞坏死。高剂量Epi可显著降低血清AST和ALT水平,减轻肝脏病理损伤,并显著可降低TNF-α水平和升高IL-10水平(1)8LPS组,P均〈0.05),但对IL-1β水平无影响。中、低剂量Epi对LPS致炎症性肝损害无明显保护作用。结论 Epi可通过抗炎作用减轻LPS诱导的炎症性肝损害。 相似文献
48.
Litjens NH Rademaker M Ravensbergen B Rea D van der Plas MJ Thio B Walding A van Dissel JT Nibbering PH 《European journal of immunology》2004,34(2):565-575
Psoriasis vulgaris, a type-1 cytokine-mediated chronic skin disease, can be treated successfully with fumaric acid esters (FAE). Beneficial effects of this medication coincided with decreased production of IFN-gamma. Since dendritic cells (DC) regulate the differentiation of T helper (Th) cells, this study focussed on effects of monomethylfumarate (MMF, bioactive metabolite of FAE) on polarization of monocyte-derived DC. MMF-incubated, lipo-polysaccharide-stimulated DC (MMF-DC) produced dramatically (p<0.05) reduced levels of IL-12p70 and IL-10 (8+/-4% and 20+/-4%, respectively) compared to control DC. MMF-DC were mature. MMF affected polarization of DC irrespective of polarization factor(s) and ligands for the various Toll-like receptors used. Coculture of MMF-DC with naive and primed allogenous Th cells resulted in lymphocytes producing less IFN-gamma, i.e. 59% and 54% of that by the respective Th cells cocultured with control DC. IL-4 production by primed, but not naive Th cells cocultured with MMF-DC was decreased as compared to cocultures with control DC. IL-10 production by naive and primed Th cells cocultured with MMF-DC and control DC did not differ. In addition, MMF inhibited LPS-induced NF-kappaB activation in DC. Together, beneficial effects of FAE in psoriasis involve modulation of DC polarization by MMF such that these cells down-regulate IFN-gamma production by Th cells. 相似文献
49.
目的: 探讨肾癌(RCC)抗原致敏树突状细胞(DC)与同源细胞因子诱导杀伤细胞(CIK)共培养后的DC-CIK细胞对RCC的杀伤活性。 方法: 将健康成人外周血单个核细胞(PBMC)来源的DC经RCC(786-0细胞株)抗原致敏后与同源CIK细胞共培养,实验分3组:RCC抗原致敏DC与CIK共培养组(A组),未致敏DC与CIK共培养组(B组),单纯CIK组(C组)。流式细胞仪检测DC及CIK免疫表型。MTT法检测3组效应细胞对786-0细胞杀伤活性。 结果: 效靶比 20∶1 时,A、B、C组对786-0细胞杀伤活性分别为(70.64±8.26)%、(53.40±7.33)%、(46.64±6.01)%,各组比较差异显著(P<0.05);以前列腺癌PC3细胞作靶细胞对照,A组对786-0及PC3细胞的杀伤活性有显著差异(P<0.05)。 结论: RCC抗原致敏DC与CIK共培养后的DC-CIK细胞可明显提高CIK细胞对RCC的杀伤特异性和杀伤活性。 相似文献
50.
Ethinyl estradiol treats collagen-induced arthritis in DBA/1LacJ mice by inhibiting the production of TNF-alpha and IL-1beta 总被引:3,自引:0,他引:3
Subramanian S Tovey M Afentoulis M Krogstad A Vandenbark AA Offner H 《Clinical immunology (Orlando, Fla.)》2005,115(2):162-172
We previously demonstrated the therapeutic effects of ethinyl estradiol (EE), an orally active estrogen and a component of birth control pills, in encephalitogenic autoimmune encephalomyelitis (EAE). In this study, we report the effectiveness of EE in treating collagen-induced arthritis (CIA) induced with bovine type II collagen (bCII) in DBA/1LacJ mice, a CIA susceptible strain. Both low and high doses of EE notably suppressed clinical and histological signs of CIA in a dose-dependent manner compared to vehicle-treated controls. Oral treatment with EE decreased proliferation and secretion of pro-inflammatory factors, TNF-alpha IFN-gamma, MCP-1 and IL-6 by bCII peptide-specific T cells, production of bCII-specific IgG2a antibodies, and mRNA for cytokines, chemokines and chemokine receptors in joint tissue. This is the first report demonstrating effective treatment of joint inflammation and clinical signs of CIA with orally administered ethinyl estradiol, thus supporting its possible clinical use for treating rheumatoid arthritis in humans. 相似文献