全文获取类型
收费全文 | 159篇 |
免费 | 22篇 |
国内免费 | 15篇 |
专业分类
196篇 |
出版年
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 8篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 9篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 11篇 |
2013年 | 13篇 |
2012年 | 12篇 |
2011年 | 11篇 |
2010年 | 9篇 |
2009年 | 11篇 |
2008年 | 10篇 |
2007年 | 10篇 |
2006年 | 10篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2002年 | 3篇 |
2001年 | 3篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1993年 | 5篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 4篇 |
1984年 | 6篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有196条查询结果,搜索用时 15 毫秒
71.
Emad F. Eskander Ahmed A. Abd-Rabou Mervat S. Mohamed Shaymaa M.M. Yahya Ashraf El Sherbini Olfat G. Shaker 《Gene》2014
The hepatitis C virus (HCV), the main cause of morbidity and mortality, is endemic worldwide. HCV causes cirrhosis and other complications that often lead to death. HCV is most common in underdeveloped nations, with the highest prevalence rates in Egypt. Tumor suppressor gene (P53) induces the expression of apoptotic antigen-1 gene (APO-1) by binding to its promoter for mediating apoptosis; an important mechanism for limiting viral replication. This study aims at investigating the impact of P53 72 Arg/Pro and APO-1 − 670 A/G polymorphisms on HCV genotype 4a susceptibility. Two hundred and forty volunteers were enrolled in this study and divided into two major groups; 160 HCV infected patient group and 80 healthy control group. HCV patients were classified according to Metavir scoring system into two subgroups; 72 patients in F0/1-HCV subgroup (patients with no or mild fibrotic stages) and 38 patients in F3/4-HCV subgroup (patients with advanced fibrotic stages). Quantification of HCV-RNA by qRT-PCR and fibrotic scores as well as genotyping of HCV-RNA, P53 at 72 Arg/Pro, and APO-1 at − 670 A/G were performed for all subjects. It was resulted that F0/1-HCV patients have significant differences of P53 at 72 (Pro/Pro and Arg/Arg) genotypes and dominant/recessive genetic models as well as APO-1 − 670 A/A genotype and dominant genetic model as compared to F3/4-HCV patients. Moreover, HCV patients have significant differences of P53 at 72 (Pro/Pro) genotype and recessive genetic model as well as APO-1 − 670 A/A genotype and dominant genetic model as compared to those of healthy individuals. Finally, it was concluded that P53 rs 1042522 (Pro/Pro and Arg/Arg) genotypes and APO-1 rs 1800682 A/A genotype may be potentially used as sensitive genetic markers for HCV genotype 4a susceptibility. 相似文献
72.
对景德镇市2004-2005年报告急性弛缓性麻痹(AFP)病例进行的流行病学分析,按AFP监测系统主要指标进行了评价。期间,全市监测系统共报告AFP病例16例,其中外地6例,本地实际报告10例,15岁以下儿童AFP平均报告率1.25/10万。监测系统主要指标除14天内双份合格大便标本采集率未达标准外,其余均达标准。 相似文献
73.
74.
A new electrochemical immunoassay of alpha-fetoprotein (AFP) was developed on an organic–inorganic hybrid nanostructure-functionalized carbon electrode by coupling with magnetic bionanolabels. Multi-walled carbon nanotubes (CNTs), single-stranded DNA, thionine and AFP were utilized for the construction of the immunosensor, while the core–shell Fe3O4-silver nanocomposites were employed for the label of horseradish peroxidase-anti-AFP conjugates (HRP-anti-AFP-AgFe). Electrochemical measurement toward AFP was carried out by using magnetic bionanolabels as traces and H2O2 as enzyme substrate with a competitive-type immunoassay mode. Experimental results indicated that the immunosensors with carbon nanotubes and DNA exhibited better electrochemical responses than those of without carbon nanotubes or DNA. Under optimal conditions, the electrochemical immunosensor by using HRP-anti-AFP-AgFe as signal antibodies exhibited a linear range of 0.001–200 ng mL−1 AFP with a low detection limit of 0.5 pg mL−1 at 3sB. Both intra- and inter-assay coefficients of variation were 7.3%, 9.4%, 8.7% and 10.2%, 7.8%, 9.4% toward 0.01, 30, 120 ng mL−1 AFP, respectively. The specificity and stability of the electrochemical immunoassay were acceptable. In addition, the methodology was validated for 12 clinical serum specimens including 9 positive specimens and 3 normal specimens, receiving a good correlation with the results obtained from the referenced electrochemiluminescence assay. 相似文献
75.
肝癌是全球最常见的恶性肿瘤之一,多数患者确诊时已属中晚期。5年以上长期生存率仅为10%左右。肝癌的早期诊断成为提高患者长期生存率的最佳有效途径。近年来,血清肿瘤分子标志物已经成为肝癌早期诊断研究领域的研究热点之一血清甲胎蛋白(AFP)检测是当前诊断肝癌常用而又重要的方法。对肝癌的确诊、预后推测、疗效判断及复发转移的监测具有良好的临床价值。甲胎蛋白异质体(AFP-L3)和脱α-羧基凝血酶原(DCP)在预测肝癌预后方面可能优于AFP。磷脂酰基醇蛋白聚糖3(GPC-3)和α-L岩藻糖苷酶(AFU)作为AFP的补充,能够大幅提高肝癌诊断的正确率。血管内皮生长因子(VEGF)、胰岛素样生长因子Ⅱ(IGF-Ⅱ)和高尔基Ⅱ型跨膜蛋白(GP-73)过表达发生在肝癌早期,有可能成为肝癌早期诊断指标。凋亡早期蛋白(M30)可以作为监测癌细胞凋亡的重要生物标记。细胞质胸苷激酶(TK1)、肝细胞生长因子(HGF)和CD147抗原分子在多种癌组织包括肝癌中显著高表达。本文对国外近几十年来肝癌血清标志物研究的一些成果进行了总结和评价,以期为国内学者进行此类研究提供一定的借鉴。 相似文献
76.
Jinjin Guo Xiaowei HanJunchun Wang Junqing ZhaoZilin Guo Yuzhong Zhang 《Analytical biochemistry》2015
In this study, a novel tracer, horseradish peroxidase (HRP) functionalized gold nanorods (Au NRs) nanocomposites (HRP–Au NRs), was designed to label the signal antibodies for sensitive electrochemical measurement of alpha-fetoprotein (AFP). The preparation of HRP–Au NRs nanocomposites and the labeling of secondary antibody (Ab2) were performed by one-pot assembly of HRP and Ab2 on the surface of Au NRs. The immunosensor was fabricated by assembling carbon nanotubes (CNTs), Au NRs, and capture antibodies (Ab1) on the glassy carbon electrode. In the presence of AFP antigen, the labels were captured on the surface of the Au NRs/CNTs via specific recognition of antigen–antibody, resulting in the signal intensity being clearly increased. Differential pulse voltammetry (DPV) was employed to record the response signal of the immunosensor in phosphate-buffered saline (PBS) containing hydrogen peroxide (H2O2) and 3,3′,5,5′-tetramethylbenzidine (TMB). Under optimal conditions, the signal intensity was linearly related to the concentration of AFP in the range of 0.1–100 ng ml−1, and the limit of detection was 30 pg ml−1 (at signal/noise [S/N] = 3). Furthermore, the immunoassay method was evaluated using human serum samples, and the recovery obtained was within 99.0 and 102.7%, indicating that the immunosensor has potential clinical applications. 相似文献
77.
Thecurrenttreatmentsofhepatocellularcarcinoma(HCC)aredisappointingandarelimitedtotumorresectionortransplantation.GenetherapyisanalternativestrategythathasbeenwidelyinvestigatedforthetreatmentofsolidtumorslikeHCC.Highconcentrationofαfetoprotein(AFP)iscur… 相似文献
78.
移植细胞的增殖和分化需要微环境支持。作为最重要的微环境成分,肌成纤维细胞在肿瘤的生长过程中发挥着重要作用。该实验Hepa1-6肿瘤细胞上清液在体外激活成纤维细胞分化为肌成纤维细胞,探讨肌成纤维细胞上清对小鼠胚胎肝干细胞(embryonic hepatic stem cells,EHSCs)HP14.5增殖和分化的影响。实验将EHSCs HP14.5分为三组:DMEM培养液处理组(DMEM组)、成纤维细胞上清液处理组(CMFb组)及肌成纤维细胞上清液处理组(CMAFb组)。MTT法绘制三组HP14.5细胞生长曲线图,免疫荧光法及Real-time PCR法检分别测白蛋白(albumin,ALB)、甲胎蛋白(alpha fetoprotein,AFP)、细胞角蛋白18(cytokeratin 18,CK18)的蛋白及mRNA表达情况,PAS染色法检测糖原合成状况。MTT法检测显示,CMAFb组胚胎肝干细胞增殖明显速度较其他两组快。免疫荧光染色及Real-time PCR结果显示,HP14.5培养5 d后,CMAFb组ALB和CK18的蛋白及mRNA表达水平以及糖原合成水平显著高于CMFb组及DMEM组,而AFP蛋白和mRNA表达水平明显降低。该实验表明,Hepa1-6激活的成纤维细胞能促进胚胎干肝细胞的增殖以及分化为有功能的成熟肝细胞。 相似文献
79.
目的:分析miR-200a及AFP在肝癌、肝硬化患者血清中的表达水平并进行比较,探索其成为肝癌早期诊断血清标志物的可能性。方法:临床收集肝正常、肝硬化、肝癌患者血液标本。运用实时定量PCR技术检测血清miR-200a的相对表达情况,血清AFP水平从临床资料中提取。结果:临床标本分析结果显示,miR-200a在肝硬化及肝癌患者中均显著下调(P<0.05),AFP仅在肝癌患者中出现异常表达。结论:血清miR-200a极大程度地参与了肝癌发生,对肝硬化及肝癌具有一定的诊断价值。 相似文献
80.
甲胎蛋白对HeLa细胞N-ras、p53和p21~(ras)表达的促进作用 总被引:3,自引:0,他引:3
大量研究已证明甲胎蛋白 (alpha fetoprotein ,AFP)对肿瘤细胞的增殖具有调节作用 .为探讨AFP对细胞生长促进作用的分子机理 ,采用从人脐带血中提取的AFP作用于体外培养的HeLa细胞 ,用Northern印迹分析法分析不同作用时间时细胞N rasmRNA的表达以及用Western印迹分析法分析p5 3、p2 1ras的表达 .结果发现 ,在AFP(2 0mg L)作用后 ,HeLa细胞的N rasmRNA、p5 3蛋白质和p2 1ras蛋白质的表达量与对照组比较在 12h和 2 4h时都有明显增加 .AFP的作用均可被抗AFP单克隆抗体所拮抗 .实验结果提示 ,AFP对细胞生长的调节作用可能通过促进这些原癌基因的表达来实现 . 相似文献