全文获取类型
收费全文 | 64篇 |
免费 | 10篇 |
国内免费 | 5篇 |
专业分类
基础医学 | 4篇 |
口腔科学 | 10篇 |
临床医学 | 3篇 |
内科学 | 11篇 |
神经病学 | 3篇 |
特种医学 | 1篇 |
外科学 | 6篇 |
综合类 | 17篇 |
药学 | 18篇 |
中国医学 | 4篇 |
肿瘤学 | 2篇 |
出版年
2020年 | 2篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 5篇 |
2011年 | 1篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 8篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有79条查询结果,搜索用时 31 毫秒
31.
We recently found that erythroblast-like cells derived from human leukaemia K562 cells express C5a receptor (C5aR) and produce its antagonistic and agonistic ligand ribosomal protein S19 (RP S19) polymer, which is cross-linked between K122 and Q137 by tissue transglutaminases. RP S19 polymer binds to the reciprocal C5aRs on erythroblast-like cells and macrophage-like cells derived from human monocytic THP-1 cells and promotes differentiation into reticulocyte-like cells through enucleation in vitro. To examine the roles of RP S19 polymer in mouse erythropoiesis, we prepared Q137E mutant RP S19 gene knock-in C57BL/6J mice. In contrast to wild-type mice, erythroblast numbers at the preliminary stage (CD71high/TER119low) in spleen based on transferrin receptor (CD71) and glycophorin A (TER119) values and erythrocyte numbers in orbital artery bloods were not largely changed in knock-in mice. Conversely, erythroblast numbers at the early stage (CD71high/TER119high) were significantly decreased in spleen by knock-in mice. The reduction of early erythroblast numbers in spleen was enhanced by the phenylhydrazine-induced pernicious anemia model knock-in mice and was rescued by a functional analogue of RP S19 dimer S-tagged C5a/RP S19. These data indicated that RP S19 polymer plays the roles in the early erythroblast differentiation of C57BL/6J mouse spleen. 相似文献
32.
目的观察血红素对人肾小管上皮细胞HK-2的损伤作用。方法体外培养人肾小管上皮HK-2细胞,经50、100、150、200μmol/L血红素处理3、6、12 h后,MTT法检测细胞活性,光镜、电镜观察细胞病理形态改变。结果与对照组比较,50μmol/L血红素组细胞活性未见明显变化,100、150、200μmol/L血红素明显降低HK-2细胞活性;光镜下可见细胞皱缩、变圆;超微结构改变主要为微绒毛数量减少、内质网扩张和空化等。结论一定浓度的血红素降低HK-2细胞活性,引起其形态学改变。 相似文献
33.
血晶素促进缺氧大鼠肺组织诱导型血红素氧合酶基因的表达 总被引:6,自引:1,他引:6
目的 研究血晶素 (Hemin)对缺氧大鼠肺组织诱导型血红素氧合酶 (HO 1)表达的影响。方法 常压缺氧 15d复制缺氧性肺动脉高压大鼠模型 ,分为 3组 :正常对照组、单纯缺氧组和血晶素组。应用逆转录聚合酶链反应 (RT PCR)检测大鼠肺组织HO 1mRNA水平 ,双波长分光光度法检测动脉血中一氧化碳血红蛋白 (COHb)的含量 ,并用右心导管检测右心室收缩压。结果 缺氧 15d大鼠肺组织HO 1mR NA水平及血中COHb较正常大鼠升高 (P <0 0 1) ,同时右心室收缩压 (RVSP)升高 (P <0 0 1)。经血晶素干预后 ,使缺氧大鼠HO 1mRNA和COHb进一步增高 ,而RVSP降低(P <0 0 1或P <0 0 5 )。结论 血晶素能够上调HO 1基因在缺氧大鼠肺组织中的表达 ,促进内源性CO生成 ,抑制大鼠缺氧性肺动脉高压的形成 相似文献
34.
目的 研究血晶素对大鼠肺组织血小板源性生长因子B链 (PDGF B)基因表达的影响 ,探讨血晶素降低缺氧大鼠右心室收缩压 (RVSP)和改善缺氧性肺血管重构的机制。方法 用右心导管检测RVSP ;以双波长分光光度法测定动脉血中碳氧血红蛋白 (COHb)的含量 ;用免疫组织化学染色观察PDGF B、增殖细胞核抗原 (PCNA)蛋白的表达 ;用原位杂交检测PDGF BmRNA的定位并用图象分析检测其水平。结果 ①正常大鼠肺腺泡内动脉 (IAPA)管壁PDGF BmR NA原位杂交及PDGF B、PCNA免疫组织化学染色结果为阴性 ,而缺氧大鼠的上述实验结果均为阳性 ,同时缺氧大鼠动脉血中COHb的含量较正常对照组大鼠高 1 8倍 (P <0 0 1)。②血晶素可使动脉血中COHb含量较单纯缺氧组进一步增多 (P <0 0 5 ) ,抑制缺氧大鼠RVSP的升高 (P <0 0 1) ,肺组织IAPA管壁PDGFmRNA原位杂交及PDGF B、PCNA免疫组织化学染色虽为阳性 ,但弱于单纯缺氧组 ,经图像分析差异有显著性 (P <0 0 1或 0 0 5 )。结论 血晶素促进内源性CO的产生 ,使缺氧大鼠肺组织PDGF B基因表达下调 ,间接地抑制缺氧状态下血管壁平滑肌细胞过度增殖引起的肺血管重构 ,这可能是血晶素改善大鼠缺氧性肺动脉高压的原因之一 相似文献
35.
脑红蛋白对大鼠局灶性脑缺血组织的保护作用 总被引:1,自引:0,他引:1
目的探讨增加脑红蛋白(neuroglobin,Ngb)表达对大鼠在体局灶性脑缺血组织保护作用的影响。方法采用Hemin诱导脑红蛋白表达的方法,将SD大鼠随机分为5组,分别为假手术对照组、手术组、术后1h Hemin干预组、术后2h Hemin干预组、术后6h Hemin干预组。5组大鼠于术后24h检测脑梗死体积比,通过免疫组织化学及Western blot分析脑红蛋白表达情况。结果术后各时相点Hemin干预组脑梗死体积比较手术组有显著性差异(P〈0.05);各干预组间比较,术后1h Hemin干预组脑梗死体积比较术后2h、术后6h Hemin干预组显著缩小(P〈0.05)。免疫组化分析,各时相点Hemin干预组Ngb阳性神经元数量较手术组增多,以术后1h Hemin干预组最明显。Western blot分析提示手术组、各时相点Hemin干预组Ngb表达均有非常显著升高(P〈0.01)。与手术组比较,术后1h Hemin干预组升高非常显著(P〈0.01),术后2h Hemin干预组升高显著(P〈0.05),术后6h组无明显差异(P〉0.05)。Ngb表达与脑梗死体积比呈负相关。结论大鼠急性局灶性脑缺血后增加脑红蛋白表达可以减轻缺血脑组织损伤。 相似文献
36.
Hemin, a heme oxygenase-1 inducer, improves aortic 总被引:6,自引:1,他引:6
Background Under an insulin resistance (IR) state, overproduction of reactive oxygen species (ROS) may be playing a major role in the pathogenesis of endothelial dysfunction, hypertension and atherosclerosis. Recently, increasing attention has been drawn to the beneficial effects of heme oxygenase-1 (HO-1) in the cardiovascular system. This study aimed to investigate the effects of HO-1 on vascular function of thoracic aorta in IR rats and demonstrate the probable mechanisms of HO-1 against endothelial dysfunction in IR states.
Methods Sprague-Dawley (SD) rats fed with high-fat diet for 6 weeks and the IR models were validated with hyperinsulinemic-euglycemic clamp test. Then the IR rat models (n=-44) were further randomized into 3 subgroups, namely, the IR control group (n=26, in which 12 were sacrificed immediately and evaluated for all study measures), a hemin treated IR group (n=-10) and a zinc protoporphyrin-Ⅸ (ZnPP-Ⅸ) treated IR group (n=-8) that were fed with a high-fat diet. Rats with standardized chow diet were used as the normal control group (n=-12). The rats in IR control group, hemin treated IR group and ZnPP-Ⅸ treated IR group were subsequently treated every other day with an intraperitoneal injection of normal saline, hemin (inducer of HO-1, 30 μmol/kg) or ZnPP-Ⅸ (inhibitor of HO-1, 10 μmol/kg) for 4 weeks. Rats in the normal control group remained on a standardized chow diet and were treated with intraperitoneal injections of normal saline every other day for 4 weeks. Systolic arterial blood pressure (SABP) was measured by tail-cuffed microphotoelectric plethysmography. The blood carbon monoxide (CO) was measured by blood gas analysis. The levels of nitdc oxide (NO), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), blood glucose (BG), insulin, total cholesterol (TC) and triglyceride (TG) in serum, and the levels of total antioxidant capacity (TAOC), malondialdehyde (MD 相似文献
Methods Sprague-Dawley (SD) rats fed with high-fat diet for 6 weeks and the IR models were validated with hyperinsulinemic-euglycemic clamp test. Then the IR rat models (n=-44) were further randomized into 3 subgroups, namely, the IR control group (n=26, in which 12 were sacrificed immediately and evaluated for all study measures), a hemin treated IR group (n=-10) and a zinc protoporphyrin-Ⅸ (ZnPP-Ⅸ) treated IR group (n=-8) that were fed with a high-fat diet. Rats with standardized chow diet were used as the normal control group (n=-12). The rats in IR control group, hemin treated IR group and ZnPP-Ⅸ treated IR group were subsequently treated every other day with an intraperitoneal injection of normal saline, hemin (inducer of HO-1, 30 μmol/kg) or ZnPP-Ⅸ (inhibitor of HO-1, 10 μmol/kg) for 4 weeks. Rats in the normal control group remained on a standardized chow diet and were treated with intraperitoneal injections of normal saline every other day for 4 weeks. Systolic arterial blood pressure (SABP) was measured by tail-cuffed microphotoelectric plethysmography. The blood carbon monoxide (CO) was measured by blood gas analysis. The levels of nitdc oxide (NO), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), blood glucose (BG), insulin, total cholesterol (TC) and triglyceride (TG) in serum, and the levels of total antioxidant capacity (TAOC), malondialdehyde (MD 相似文献
37.
目的:体外观察血红素氧合酶-1(heme oxygenase-1,HO-1)对人胃癌细胞SGC7901 5-氟尿嘧啶(5-FU)化疗敏感性的影响及其可能的机制?方法:应用不同浓度锌原卟啉(ZnPP)?氯化血红素(Hemin)单独或联合5-FU作用于人胃癌SGC7901细胞不同时间,四甲基偶氮唑盐(MTT)法观察药物对细胞生长抑制作用;Western blot分析细胞HO-1蛋白表达变化;流式细胞术检测细胞凋亡率;活性氧(ROS)检测试剂盒分析其凋亡机制?结果:ZnPP和5-FU均可明显抑制人胃癌SGC7901细胞生长,呈剂量依赖性;5-FU联用ZnPP(10 μmol/L)与单用药相比,明显提高了细胞生长抑制率和凋亡率(P < 0.05),联用Hemin(10 μmol/L)则明显降低细胞生长抑制率和凋亡率(P < 0.05);人胃癌SGC7901细胞中可见HO-1表达,单用5-FU或Hemin后均能使其表达增强,联用ZnPP可逆转此现象;单用5-FU与对照组比较,细胞内ROS活性明显增高,联用后ZnPP可进一步提高细胞内ROS活性(P < 0.05),而联用Hemin明显降低细胞内ROS活性水平(P < 0.05)?结论:ZnPP抑制HO-1表达,能够增强人胃癌SGC7901细胞对5-FU化疗敏感性,这一作用可能与增加细胞内ROS活性有关? 相似文献
38.
目的研究氯化高铁血红素(Hm)对红系细胞(K562细胞)血红蛋白合成及红细胞生成素(EPO)受体表达的诱导作用。方法采用不同剂量Hm对体外培养K562细胞进行诱导,用联苯胺染色对诱导细胞血红蛋白进行定性测定,通过放射性标记配基结合实验测定Hm诱导后K562细胞膜EPO受体的变化。结果诱导组血红蛋白阳性细胞比例由对照组的3.5%增加到34.3%(P<0.05)。K562细胞对EPO的诱导作用不敏感,而经Hm体外诱导48h后,其对EPO的敏感性明显增加。诱导后K562细胞膜EPO受体的数量由对照组的3~8个/细胞,诱导组为6~25个/细胞(P<0.01)。结论Hm能增加K562细胞血红蛋白合成及细胞膜EPO受体的表达 相似文献
39.
目的 研究胚胎肝发育相关基因 1(EDAG 1)在红系肿瘤分化中的表达及意义。方法 用细胞生物学、RT PCR及Northern杂交法。结果 含 4 0× 10 -5mol·L-1氯高铁血红素 (Hemin)的RPMI 16 40培养K5 6 2细胞 5天 ,可使70 %~ 80 %细胞呈现正常红系特征 ;EDAG 1、c fos表达降低。结论 Hemin可诱导红白血病细胞分化 ;EDAG 1、c fos表达下调可能与其有关。 相似文献
40.
血红素加氧酶-1诱导对鼠肝缺血再灌注损伤的保护作用 总被引:1,自引:0,他引:1
目的研究血红素加氧酶-1(heme oxygenase-1,HO-1)在鼠肝缺血再灌注损伤肝组织中的表达及其作用。方法建立小鼠部分肝脏热缺血再灌注损伤模型,36只清洁级Balb/C小鼠随机分为3组: 假手术组(S组)、缺血/再灌注损伤组(I/R组)、HO-1诱导剂氯化高铁血红素(hemin)预处理组(HM组)。免疫组化半定量分析肝组织HO-1蛋白的表达,检测血清AST和ALT,肝组织丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性,并观察肝组织的病理变化。结果与S组比较,I/R组HO-1蛋白表达显著增强,hemin预处理后,HO-1蛋白表达较I/R组增高(P<0.01)。I/R组AST,ALT活性和MDA的含量显著高于S组,而HM组均显著低于I/R组(P<0.01);I/R组SOD活性下降,而HM组显著高于I/R组(P<0.01)。HM组病理损伤程度明显轻于I/R组。结论 HO-1在鼠肝缺血再灌注损伤肝组织中表达上调,对肝脏具有保护效应。 相似文献