全文获取类型
收费全文 | 455篇 |
免费 | 28篇 |
国内免费 | 17篇 |
专业分类
妇产科学 | 8篇 |
基础医学 | 85篇 |
口腔科学 | 6篇 |
临床医学 | 17篇 |
内科学 | 58篇 |
皮肤病学 | 3篇 |
神经病学 | 19篇 |
特种医学 | 4篇 |
外科学 | 22篇 |
综合类 | 52篇 |
预防医学 | 13篇 |
眼科学 | 6篇 |
药学 | 105篇 |
中国医学 | 64篇 |
肿瘤学 | 38篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 11篇 |
2016年 | 12篇 |
2015年 | 13篇 |
2014年 | 34篇 |
2013年 | 33篇 |
2012年 | 25篇 |
2011年 | 54篇 |
2010年 | 48篇 |
2009年 | 43篇 |
2008年 | 40篇 |
2007年 | 24篇 |
2006年 | 23篇 |
2005年 | 15篇 |
2004年 | 30篇 |
2003年 | 15篇 |
2002年 | 14篇 |
2001年 | 9篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
排序方式: 共有500条查询结果,搜索用时 46 毫秒
1.
Interleukin-8 (IL-8), C5a and N-formyl-methionyl-leucyl-phenylalanine (fMLP) are chemotactic peptides with predominant effects on leukocytes during inflammation. With emphasis on C5a we studied the regulation of the production of IL-8 by human umbilical vein endothelial cells (HUVEC) in vitro. Primary HUVEC cultures were incubated with IL-1, TNF, C5a and fMLP for 24 h and 48 h prior to measurement of IL-8 in supernatants of the cells by an enzyme immunoassay. Whereas IL-1 and TNF significantly increased the levels of IL-8, C5a decreased the IL-8 production after 48 h. In addition, the ability of IL-1, TNF, C5a, fMLP and IL-8 to induce cell proliferation was compared by means of a 3H-thymidine incorporation assay. In contrast with IL-1 and TNF, both C5a and fMLP increased cell proliferation of HUVEC. This increase occurred with increasing concentrations of C5a contrary to IL-8, which showed increased cell proliferation at low, but not high IL-8 concentrations. 相似文献
2.
小陷胸汤加味含药血清对人脐静脉内皮细胞分泌NO/ET-1的调节作用 总被引:3,自引:1,他引:3
目的:探讨小陷胸汤加味中药方对血管内皮细胞的保护作用。方港:建立ox-LDL损伤人脐静脉内皮细胞株(ECV-304)模型,用小陷胸汤加味含药血清处理模型,并用放免和硝酸酶还原法在药物干预6h和24h后检测细胞上清液中ET-1和NO含量。结果:100 μg/ml的ox-LDL可损伤血管内皮细胞并导致其分泌NO和ET-1功能失调,小陷胸汤加味含药血清通过影响NO/ET-1的分泌而明显改善此失调状态。结论:小陷胸汤加味中药通过调节NO/ET-1水平显著拮抗ox-LDL对血管内皮细胞损害,具有防治AS的作用。 相似文献
3.
Müller AM Hermanns MI Skrzynski C Nesslinger M Müller KM Kirkpatrick CJ 《Experimental and molecular pathology》2002,72(3):221-229
EC culture models are essential to study pathological alterations of endothelial cells (ECs) in pulmonary vascular diseases under standardized conditions. Nevertheless, little is known about the spectrum of alterations of vessel-specific endothelial phenotypes in monolayer cultures. For the comparative study of endothelial markers in vivo and in vitro we investigated immunohistochemically the expression of PECAM-1, vWf, and CD34 by pulmonary ECs in vivo and in stimulated/unstimulated human umbilical vein endothelial cells (HU-VEC) and human pulmonary microvascular endothelial cells (HPMEC). In vivo, vessel type-specific expression patterns were found for vWf and CD34, while PECAM-1 was homogeneously and strongly expressed. While all HUVEC showed a marked vWf staining, about two-thirds of HPMEC exhibited a strong and the rest a moderate vWf staining. In both in vitro models all ECs were clearly PECAM-1-positive. However, only about 20% of the HUVEC and HPMEC were CD34-positive. Our results demonstrate the reduced expression of vessel type-specific endothelial phenotypes by endothelial monolayer cultures, stressing the need to improve culture conditions as well as develop cocultures and three-dimensional culture models. Moreover, the need for endothelial markers specific for single microvascular type ECs becomes obvious in order to establish cultures consisting of only one microvascular ECs subpopulation. 相似文献
4.
霉酚酸对趋化性细胞因子I-TAC的表达及其功能的影响 总被引:2,自引:0,他引:2
研究探讨霉酚酸(MPA)对趋化性细胞因子I-TAC的表达及其功能的影响。分别在IFN-γ加入之前、同时、之后加MPA于培养的ECV-304细胞中,以RT-PCR检测其I-TAC mRNA的表达水平。PBMC经不同浓度MPA(10、100、1 000ng/ml)处理12 h后,采用微迁移板技术观察MPA对I-TAC趋化作用的影响。MTT法测定不同浓度MPA(10、100、1 000ng/ml)对I-TAC促PBMC增殖效应的影响。结果显示,在不同时间加入MPA处理的各组,其I-TAC/GAPDH比值均显著地小于对照组(P<0.01),而MPA处理组之间无显著性差异(P>0.05)。MPA处理组PBMC的迁移指数和MTT试验的A值与相应对照组相比均显著下降(P<0.05)。这些结果提示,MPA对I-TAC在内皮细胞上表达及其趋化、促增殖功能具有抑制作用。MPA的这些新发现的功能可能是霉酚酸酯(MMF)抗移植排斥的重要机制之一。 相似文献
5.
Katrin Trummal Külli T?nism?gi Ene Siigur Anu Aasp?llu Annika Lopp Tarvo Sillat Riste Saat Lagle Kasak Indrek Tammiste Priit Kogerman Nisse Kalkkinen Jüri Siigur 《Toxicon》2005,46(1):46-61
A novel endothelial cell apoptosis inducing metalloprotease (VLAIP) was found in the snake venom of Vipera lebetina. This metalloprotease is a heterodimeric glycoprotein with molecular mass of about 106 kDa. The protease hydrolyzes azocasein, fibrinogen and oxidized insulin B-chain. The enzyme readily hydrolyzes the Aalpha-chain and more slowly Bbeta-chain of fibrinogen. VLAIP does not cleave fibrin. The complete amino acid sequences of the two different monomers of VLAIP are deduced from the nucleotide sequences of cDNAs encoding these proteins. The full-length cDNA sequences of the VLAIP-A and VLAIP-B encode open reading frames of 616 and 614 amino acids that include signal peptide, propeptide and mature metalloproteinase with disintegrin-like and cysteine-rich domains. VLAIP belongs to the metalloprotease/disintegrin family of reprolysins and has high identity with the proteins that induce apoptosis of endothelial cells. Treatment of HUVEC cells with VLAIP induces changes in the attachment of cells to the substrate and causes cell death. We demonstrated that VLAIP inhibits endothelial cell adhesion to extracellular matrix proteins: fibrinogen, fibronectin, vitronectin, collagen I, and collagen IV. The induction of apoptosis by VLAIP was shown by means of a typical DNA fragmentation pattern of apoptotic cells as well as by monitoring phosphatidylserine externalization using annexin V-FITC staining and flow cytometric analysis. 相似文献
6.
槲皮素抑制血管生成作用的实验研究 总被引:21,自引:1,他引:21
目的 研究槲皮素 (Quercetin)对血管生成和培养的人脐静脉内皮细胞 (HUVEC)的影响。方法 采用生长因子 (血管内皮细胞生长因子VEGF、碱性成纤维细胞生长因子bFGF)诱导的鸡胚绒毛尿囊膜 (CAM)血管增生模型观察槲皮素对血管生成的影响 ;利用培养的HUVEC ,用MTT法观察槲皮素抑制内皮细胞增殖的作用 ;流式细胞仪观察槲皮素对HUVEC细胞周期的影响。结果 槲皮素 (0 1、0 0 5和 0 0 2 5mmol·L-1)能明显抑制VEGF诱导的CAM小血管生成 ;槲皮素 (0 1和 0 0 5mmol·L-1)能明显抑制bFGF诱导的CAM小血管生成 ;槲皮素 (2 4 0、12 0 μmol·L-1和 6 0 μmol·L-1)对内皮细胞增殖有抑制作用 ,抑制率分别为 6 7 0 %、5 8 1%和39 7% ;槲皮素 (2 4 0、12 0 μmol·L-1)能显著导致HUVEC的S、G2 期阻滞。结论 槲皮素能抑制VEGF和bFGF诱导的血管生成 ,且对内皮细胞增殖具有抑制作用。 相似文献
7.
Sachiro Kakinoki Ji-Hun Seo Yuuki Inoue Kazuhiko Ishihara Nobuhiko Yui 《Journal of biomaterials science. Polymer edition》2013,24(11):1320-1332
Adhesion behaviors of human umbilical vein endothelial cells (HUVECs) are interestingly affected by the mobility of hydrophilic chains on the material surfaces. Surfaces with different molecular mobilities were prepared using ABA-type block copolymers consisting polyrotaxane (PRX) or poly(ethylene glycol) (PEG) central block (A block), and amphiphilic anchoring B blocks of poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB). Two different molecular mobilities of the PRX chains were designed by using normal α-cyclodextrin (α-CD) or α-CD whose hydroxyl groups were converted to methoxy groups in a given ratio to improve its molecular mobility (PRX–PMB and OMe-PRX–PMB). The surface mobility of these materials was assessed as the mobility factor (Mf), which is measured by quartz crystal microbalance with dissipation monitoring system. HUVECs adhered on OMe-PRX–PMB surface much more than PRX–PMB and PMB-block–PEG–block-PMB (PEG–PMB) surfaces. These different HUVEC adhesions were correlated with the density of cell-binding site of adsorbed fibronectin. In addition, the alignment of the actin cytoskeleton of adhered HUVECs was strongly suppressed on the PEG–PMB, PRX–PMB, and OMe-PRX–PMB in response to the increased Mf value. Remarkably, the HUVECs adhered on the OMe-PRX–PMB surface with much less actin organization. We concluded that not only the cell adhesion but also the cellular function are regulated by the molecular mobility of the outmost material surfaces. 相似文献
8.
Julia Carracedo Paula Buendía Ana Merino Sagrario Soriano Elvira Esquivias Alejandro Martín-Malo Pedro Aljama Rafael Ramírez 《Experimental gerontology》2013
Renal dysfunction is closely associated with endothelial damage leading to cardiovascular disease. However, the extent to which endothelial damage induced by uremia is modulated by aging is poorly known. Aging can render endothelial cells more susceptible to apoptosis through an oxidative stress-dependent pathway. We examined whether senescence-associated to oxidative stress determines the injury induced by the uremia in endothelial cells. 相似文献
9.
目的:通过建立H2O2 导致人脐静脉内皮细胞损伤的模型来研究狭鳕鱼皮胶原蛋白肽作用。方法:用人脐静脉内皮细胞作为体外研究对象,采用不同的浓度(40M、200M、400M)胶原蛋白和维生素E预处理12h,然后在加入50uM H2O2继续培养12h造成损伤模型。模型成功后用CCK-8检测吸光度,根据试剂盒操作检测细胞内及培养上清液谷胱甘肽过氧化物酶(GXH-PX),一氧化氮(NO)、过氧化氢酶(CAT),丙二醛(MDA)等指标的含量和活性变化。结果:经胶原蛋白预保护后细胞增值率升高,GXH-PX、CAT等活性增强,NO含量升高,丙二醛含量降低。 相似文献
10.