期刊文献+
共找到14篇文章
< 1 >
每页显示 20 50 100
Complete Genomic Sequence of a Chinese Isolate of Duck Hepatitis Virus 被引量:9
1
作者 Guang-qing LIU Fei WANG +4 位作者 Zheng NI Tao YUN Bin YU Jiong-gang HUANG Jian-Ping CHEN 《中国病毒学》 CSCD 2007年第5期353-359,共7页
The complete genomic sequence of Duck hepatitis virus 1(DHV-1) ZJ-V isolate was sequenced and determined to be 7 691 nucleotides(nt) in length with a 5'-terminal un-translated region(UTR) of 626 nt and a 3'-te... The complete genomic sequence of Duck hepatitis virus 1(DHV-1) ZJ-V isolate was sequenced and determined to be 7 691 nucleotides(nt) in length with a 5'-terminal un-translated region(UTR) of 626 nt and a 3'-terminal UTR of 315 nt(not including the poly(A) tail).One large open reading frame(ORF) was found within the genome(nt 627 to 7 373) coding for a polypeptide of 2 249 amino acids.Our data also showed that the poly(A) tail of DHV-1 has at least 22 A's.Sequence comparison revealed significant homology(from 91.9% to 95.7%) between the protein sequences of the ZJ-V isolate and those of 21 reference isolates.Although DHV-1 has been classified as an unassigned virus in the Picornaviridae family,its genome showed some unique characteristics.DHV-1 contains 3 copies of the 2A gene and only 1 copy of the 3B gene,and its 3'-NCR is longer than those of other picornaviruses.Phylogenetic analysis to do sequence homology based on the VP1 protein sequences showed that the ZJ-V isolate shares high sequence homology with the reported DHV-1 isolates(from 92.9% to 99.2%),indicating that DHV-1 is genetically stable. 展开更多
关键词 全基因序列 鸭肝炎病毒 中国 隔离
下载PDF
Replication of clinical hepatitis B virus isolate and its application for selecting antiviral agents for chronic hepatitis B patients 被引量:4
2
作者 Yin-Ping Lu Tao Guo +5 位作者 Bao-Ju Wang Ji-Hua Dong Jian-Fang Zhu Zhao Liu Meng-Ji Lu Dong-Liang Yang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第22期3490-3496,共7页
AIM: To establish a cell model harboring replicative clinical hepatitis B virus (HBV) isolates and evaluate its application in individualized selection of anti-HBV agents for chronic hepatitis B (CHB) patients. METHOD... AIM: To establish a cell model harboring replicative clinical hepatitis B virus (HBV) isolates and evaluate its application in individualized selection of anti-HBV agents for chronic hepatitis B (CHB) patients. METHODS: The full-length HBV genomic DNA from 8 CHB patients was amplified by polymerase chain reaction (PCR). All the patients were treated with lamivudine for at least seven months and finally became resistant to lamivudine. The amplified HBV DNA fragments were inserted into pHY106 vectors by Sap Ⅰ?digestion. The recombinant plasmids containing 1.1 copies of HBV genome were transiently transfected into Huh7 cell line, and the levels of HBsAg, HBeAg and intercellular HBV replicative intermediates were determined by ELISA and Southern blot analysis, respectively, with or without lamivudine and adefovir treatment. The antiviral treatment with adefovir was administered to the patients and analyzed in parallel. RESULTS: A total of 25 independent HBV isolateswere obtained from the sera of 8 patients, each patient had at least two isolates. One isolate from each individual was selected and subcloned into pHY106 vector, including 5 isolates with YVDD mutation and 3 isolates with YIDD mutation. All recombinant plasmids harboring HBV isolates were transfected into Huh7 cells. The results indicated that HBV genome carried in HBV replicons of clinical HBV isolates could effectively replicate and express in Huh7 cells. Adefovir, but not lamivudine, inhibited HBV replication both in vitro and in vivo, and in vitro inhibition was dose-dependent. CONCLUSION: The novel method described herein enables individualized selection of anti-HBV agents in clinic and is useful in future studies of antiviral therapy for CHB. 展开更多
关键词 Hepatitis B virus Chronic hepatitis B Hepatitis B virus isolate Antiviral agents
下载PDF
必须大力提高人口质量
3
作者 张纯元 《人口与经济》 1982年第6期11-13,共3页
人是在由群体组成的社会中生活的高级动物,具有双重性质,他既是生物的人,又是社会的人,既有自然属性,又有社会属性,人就是这二者的辩证统一体。人的自然属性反映在人口质量上,就是人的身体素质;人的社会属性反映在人口质量上,就是人的... 人是在由群体组成的社会中生活的高级动物,具有双重性质,他既是生物的人,又是社会的人,既有自然属性,又有社会属性,人就是这二者的辩证统一体。人的自然属性反映在人口质量上,就是人的身体素质;人的社会属性反映在人口质量上,就是人的思想素质和文化科学素质。人口质量尽管是个多含义的复合概念,但是,就其主要点来说,不外就是人的身体素质、思想素质和文化科学素质的辩证统一,也就是我们常说的德智体三个方面的统一。 提高人口质量极端重要,它既关系着我们中华民族的前途和命运,能否很快繁荣昌盛起来的问题,又关系到建设社会主义精神文明,巩固和完善社会主义制度的大业,更与我国的经济发展和四化进程有着直接的内在联系。众所周知。 展开更多
关键词 人口质量 业余教育 优生学 同基因 遗传性疾病 脑重 文化科学素质 近亲结婚 幼儿早期教育 隔离
下载PDF
不同国家近亲结婚水平比较及其变化趋势
4
作者 王修海 《青海医药杂志》 1989年第3期48-52,共5页
近亲结婚是人类遗传学和优生学的重要课题之一。不同人群近亲结婚率和平均近婚系数是人类遗传学的一项重要参数,比较不同国家和我国各民族的近亲结婚状况及其变化趋势,对于丰富我国人类遗传学研究资料,搞好优生优育工作有一定意义。国... 近亲结婚是人类遗传学和优生学的重要课题之一。不同人群近亲结婚率和平均近婚系数是人类遗传学的一项重要参数,比较不同国家和我国各民族的近亲结婚状况及其变化趋势,对于丰富我国人类遗传学研究资料,搞好优生优育工作有一定意义。国外对近亲结婚的研究较早。 展开更多
关键词 人类遗传学 近婚系数 近亲结婚 隔离 新婚姻法 宜昌地区 人类 合江地区 青海医药杂志 人口流动性
下载PDF
医学遗传学及遗传咨询的进展
5
作者 F.Vogel 施惠平 《中国生育健康杂志》 1993年第3期131-133,共3页
一、医学遗传学作为一门科学的发展 近几个世纪可看到人类及医学遗传学的一次革命,它对医学有深远的影响。 1.它解释了许多疾病及畸形的病因。 2.它有助于分析这些疾病的发病机理,也就是正常功能的障碍。 3.这些分析有助于我们发现治疗... 一、医学遗传学作为一门科学的发展 近几个世纪可看到人类及医学遗传学的一次革命,它对医学有深远的影响。 1.它解释了许多疾病及畸形的病因。 2.它有助于分析这些疾病的发病机理,也就是正常功能的障碍。 3.这些分析有助于我们发现治疗方法,在更多的情况下,是预防这些疾病。 医学遗传学的发展分以下几个阶段: 展开更多
关键词 医学遗传学 遗传咨询 产前诊断 家系图 再现风险 发病机理 遗传学方法 羊膜腔穿刺术 神经管缺陷 隔离
下载PDF
个体间的社会亲疏关系及提示方法对鸡采食行为的影响
6
作者 包跃先 《内蒙古农业大学学报(自然科学版)》 CAS 北大核心 2020年第5期1-4,共4页
将42日龄20只的名古屋鸡随机分成4群进行饲养,在6种刺激条件下,进行了采食行为社会促进效果的实验。6种刺激是指亲疏关系的同居、视觉的接触、视觉的隔离以及3种隔离材料在物理条件下的相互提示。在同居、视觉接触,玻璃和金属网的提示... 将42日龄20只的名古屋鸡随机分成4群进行饲养,在6种刺激条件下,进行了采食行为社会促进效果的实验。6种刺激是指亲疏关系的同居、视觉的接触、视觉的隔离以及3种隔离材料在物理条件下的相互提示。在同居、视觉接触,玻璃和金属网的提示条件下,采食量、采食次数比视觉隔离时显著增加(P<0.01),单独采食次数在视觉隔离的提示条件下比同居及视觉接触时明显增加(P<0.05)。以上鸡的采食行为的社会促进,是由于亲密个体之间的采食行为,在视觉和听觉刺激下被强烈的唤起。疏远个体之间,因为可能发生攻击行为,采食行为多选择在身体无法接触的场所进行。 展开更多
关键词 雌鸡 采食行为 同居个体 视觉接触 视觉隔离
原文传递
丙型肝炎病毒经抗体阴性供体向器官和组织受体传播
7
作者 Tugwell B.D Patel P.R. +1 位作者 Williams I.T. 李宏宇 《世界核心医学期刊文摘(胃肠病学分册)》 2006年第3期1-1,共1页
Background: Although hepatitis C virus (HCV) transmission through tissue transplantation has been rarely reported, a donor with undetected viremia may infect several recipients. A patient developed acute hepatitis C s... Background: Although hepatitis C virus (HCV) transmission through tissue transplantation has been rarely reported, a donor with undetected viremia may infect several recipients. A patient developed acute hepatitis C shortly after tissue transplantation. Ninety-one tissues or organs had been recovered from the donor. Objective: To determine whether the donor was the source of infection and the extent of transmission to other organ and tissue recipients. Design: Descriptive epidemiologic study; serum testing for HCV infection. Setting: Recipients were located in 16 states and 2 other countries. Participants: Donor and graft recipients. Measurements: Hepatitis C virus infection was defined as the presence of anti-HCV or HCV RNA. The authors determined the genetic relatedness of viral isolates from the donor and recipients by genotype comparison and quasi-species analysis. Results: The donor was anti-HCV-negative but was HCV RNA-positive (genotype 1a). Forty persons received transplants during 22 months. Five persons were HCV-infected before transplantation or had a genotype other than 1a, and 5 persons had no post-transplantation serum specimens available. Of the remaining 30 recipients, HCV infection occurred in 8 recipients: 3 of 3 organ recipients, 1 of 2 saphenous vein recipients, 1 of 3 tendon recipients, and 3 of 3 tendon with bone recipients. These 8 recipients had viral isolates genetically related to those of the donor. No cases occurred in recipients of skin (n = 2), cornea (n = 1), or irradiated bone (n = 16). Limitations: Post-transplantation serum specimens were unavailable for 5 recipients. Conclusions: An anti-HCV-negative donor was the source of HCV infection for 8 recipients of organs or tissues. Although HCV transmission from anti-HCV-negative donors is probably uncommon, changes in donor screening to include routine testing for HCV RNA merit further consideration to improve the safety of transplantation. 展开更多
关键词 丙型肝炎病毒 抗体阴性 组织移植 准种 描述性流行病学 隔离 血清检测 移植物 遗传相关性 隐静脉
下载PDF
甘肃兴隆山林区马麝(Moschus chrysogaster)隔离种群的生态特征 被引量:22
8
作者 刘志霄 李强 +1 位作者 康发攻 盛和林 《生态学报》 CAS CSCD 北大核心 2001年第6期964-968,共5页
兴隆山林区大约在 3 0 0 a前就已完全隔离。现有马麝种群的密度高而相对稳定 ,约为 3 0~ 50头 /km2 ,在目前密度与系统压力下 ,种群数量基本稳定在 50 0 0头左右 ,但却面临着疾病、营养不良与偷猎的威胁。因此应努力建立一个“以开发... 兴隆山林区大约在 3 0 0 a前就已完全隔离。现有马麝种群的密度高而相对稳定 ,约为 3 0~ 50头 /km2 ,在目前密度与系统压力下 ,种群数量基本稳定在 50 0 0头左右 ,但却面临着疾病、营养不良与偷猎的威胁。因此应努力建立一个“以开发养保护 ,以保护促发展”的良性循环模式 ,从而为我国自然保护区的建设和发展树立典范。 展开更多
关键词 马麝 隔离 生态特征 兴隆山林区 甘肃
下载PDF
贺兰山林区马麝隔离种群的生存现状及保护 被引量:18
9
作者 刘志霄 盛和林 +3 位作者 李元广 王绍绽 赵登海 杜和平 《生态学报》 CAS CSCD 北大核心 2000年第3期463-467,共5页
贺兰山林区是一个孤立的“林岛”,区内马麝总数量估计为 1 83~ 2 2 7头 ,主要零星地分布于陡坡林中 ,已处于濒危状态。1 980年以前马麝种群衰退的主要原因是灌木林的急剧减少 ,1 980年以后种群衰退的主要原因则是钢丝套偷猎。建立严励... 贺兰山林区是一个孤立的“林岛”,区内马麝总数量估计为 1 83~ 2 2 7头 ,主要零星地分布于陡坡林中 ,已处于濒危状态。1 980年以前马麝种群衰退的主要原因是灌木林的急剧减少 ,1 980年以后种群衰退的主要原因则是钢丝套偷猎。建立严励的“奖惩制度”。 展开更多
关键词 贺兰山 马麝 隔离 保护 数量
下载PDF
濒危植物缙云卫矛不同种群的种子萌发研究 被引量:16
10
作者 胡世俊 何平 +1 位作者 王瑞波 方兴 《林业科学》 EI CAS CSCD 北大核心 2007年第5期42-47,共6页
选取重庆特有濒危植物缙云卫矛7个相互间有不同程度空间隔离的种群,对其种子萌发特征进行研究。结果表明:7个种群的种子在实验室条件下萌发率差异极显著,种子萌发率与所处种群的大小呈极相关,大种群与小种群的种子萌发率差异达极显著水... 选取重庆特有濒危植物缙云卫矛7个相互间有不同程度空间隔离的种群,对其种子萌发特征进行研究。结果表明:7个种群的种子在实验室条件下萌发率差异极显著,种子萌发率与所处种群的大小呈极相关,大种群与小种群的种子萌发率差异达极显著水平,而各种群的种子萌发率与其所处生境的土壤因子相关性不显著。各种群的平均种子质量与种群大小及土壤条件均无关,说明种群平均种子质量是一个较为稳定的不易受影响的参数。小种群低萌发率的主要原因可能是由于近交衰退带来遗传多样性的丧失引起的,而不是环境因素的影响。研究表明:要长期保护这些小种群,应将种群统计因素与种群遗传因素结合起来考虑,增加种群中个体数目,扩大种群,提高种子萌发率,促进种群更新,才能有效地维持这些小种群的生存发展。 展开更多
关键词 种子萌发 隔离 濒危植物 缙云卫矛
下载PDF
基于隔离粒子群算法的智慧矿山5G SA网络切片部署策略 被引量:3
11
作者 蒋建峰 张凤岩 +1 位作者 孙金霞 张趁香 《国外电子测量技术》 北大核心 2022年第4期42-48,共7页
5G网络的发展促使采矿行业战略转型升级,降低采矿行业的安全风险,提高了采矿生产效率。智慧矿山5G SA(stand-alone)网络将用户面功能(UPF)下沉到矿区,控制面留在大区中心,远程控制、5G视频回传、VR/AR巡检和数据采集类等所有数据业务均... 5G网络的发展促使采矿行业战略转型升级,降低采矿行业的安全风险,提高了采矿生产效率。智慧矿山5G SA(stand-alone)网络将用户面功能(UPF)下沉到矿区,控制面留在大区中心,远程控制、5G视频回传、VR/AR巡检和数据采集类等所有数据业务均通过专网访问矿区应用服务器。提出隔离粒子群算法(PSO_I),且引入贝叶斯评估方法计算粒子平均隔离因子,将其作为约束条件改善传统粒子群算法容易陷入局部最优的缺点。基于网络切片编排开销以及物理节点资源和链路资源的利用率构造隔离适值函数,通过迭代求解快速找到切片编排方案。经过矿区实际5G网络切片编排测试,结果显示PSO_I算法能够提升切片接受率、收益成本比和链路资源利用率,在降低执行时间的同时提高了网络上行速率,PSO_I算法优化的网络上行平均速率比SecPSO、Slice和SSPS算法分别提高19%、48%和52%。 展开更多
关键词 5G网络切片 隔离粒子算法 智慧矿山 切片编排 隔离适值函数
下载PDF
Genetic diversity of oil-tea camellia germplasms revealed by ISSR analysis 被引量:1
12
作者 Lan-Ying Zhou Xiang-Nan Wang +2 位作者 Li-Ping Wang Yong-Zhong Chen Xiao-Cheng Jiang 《International Journal of Biomathematics》 2015年第5期331-354,共24页
Genetic diversity of 51 oil-tea camellia germplasms was analyzed using the optimized inter-simple sequence repeat (ISSR)-PCR reaction system with 22 primers screened from a set of 100 ISSR primers. The results showe... Genetic diversity of 51 oil-tea camellia germplasms was analyzed using the optimized inter-simple sequence repeat (ISSR)-PCR reaction system with 22 primers screened from a set of 100 ISSR primers. The results showed that 493 discernible loci with distinct elec- trophoretic bands were obtained, of which, 478 loci (96.78%) were polymorphic. This indicated that oil-tea germplasms possess abundant genetic diversities. By clustering analysis performed using softwares of NTSYS 2.10 and Winboot, 51 oil-tea germplasms were divided into two groups: Group I had 48 lines of Camellia oleifera Abel, while Group II had three C. oleifera Abel related species and their similarity coefficient was 0.62. Group I was further divided into Group I-1 and Group I-2, and their similarity coefficient (Gs) was 0.634. All members of Group I-1 originated from Hunan Province, while Group I-2 included the rest of Hunan lines and those originated from other regions of China. Analyzed by software POPGENE 1.32, the Shannon's information index (I*) of genetic polymorphism was 0.3852, the genetic diversity among different region popula- tions (Ht) was 0.2537, the genetic diversity within populations (Hs) was 0.15545, the dif- ferentiation coefficient of genetic diversity among populations (Gst) was 0.3967, and the gene flow among populations (Nm*) was 0.8262. The Nei's genetic distances between the Hunan population and the populations originated from other regions of China implied that geographic isolation strongly influenced genetic differentiation among populations. Meanwhile, seedling rootstock grafting and high grafting for tree crown produced genetic variations among clonal offsprings. 展开更多
关键词 Oil-tea camellia ISSR genetic diversity grafting.
原文传递
Study on Biological Control Of Rhlzoctonla solanl vla Trlchoderma
13
作者 WeiLin, and Liang Zhihuai Hunan Plant Protection Research Institute, Changsha 410125, China 《Hunan Agricultural Science & Technology Newsletter》 2002年第2期14-16,共3页
Strain T02-25 was selected from approximately 30 rhizosphere isolates of Trichoderma species isolated from roots of crops. Its biological activity against Rhizoctonia solani was determined for the control efficacy to ... Strain T02-25 was selected from approximately 30 rhizosphere isolates of Trichoderma species isolated from roots of crops. Its biological activity against Rhizoctonia solani was determined for the control efficacy to pepper seedling blight caused by R. solani in the field. The assay methods were treating R. solani sclerotia by Trichoderma conidial suspension (10^6cfu ml^-1) and scattering Thichoderma rice bran over the pepper root medium. The results showed that T02-25 was active against R.solani in both ways, and its control efficacy was 82.7% and 78.0%, respectively. In addition to comparison of the efficacy of the two application methods, the relationship of different factors in the control efficacy of Trichoderma against R. solani was discussed. 展开更多
关键词 TRICHODERMA biological control Rhizoctonia solani
下载PDF
利用几何形态测量学方法分析外来近似物种形态差异与亲疏关系 被引量:1
14
作者 粟海军 《生物学杂志》 CAS CSCD 北大核心 2019年第4期89-93,共5页
几何形态测量学方法是近年来生物形态学研究的热点方法。利用此方法对分类存疑的法国、比利时和意大利3处外来的丽松鼠属松鼠(Callosciurus sp.)下颌骨形态进行了比较分析,结果表明:1)所有种群均有显著的异速生长效应,个体间形变主要发... 几何形态测量学方法是近年来生物形态学研究的热点方法。利用此方法对分类存疑的法国、比利时和意大利3处外来的丽松鼠属松鼠(Callosciurus sp.)下颌骨形态进行了比较分析,结果表明:1)所有种群均有显著的异速生长效应,个体间形变主要发生在冠状突、隅突、咬肌嵴和颏孔位置,而种群间形变主要发生在隅突部分;2)判别函数分析表明,三地种群具明显形态差异,但法国种群较其他两者距离更远,而比利时与意大利种群则亲缘关系较近,由此推断后两者的外来种群可能来自同一来源或同一分类地位物种,而法国外来种群可能来自与比利时和意大利种群属不同分类地位,三者间的下颌形态变化可能与各自地理生态适应相关。研究定量和图形化了各外来种群间的下颌形变差异与分类亲疏程度,有利于进一步弄清外来物种来源与分类学地位,从而为入侵生物形态学研究提供科学参考。 展开更多
关键词 丽松鼠 外来物种 地理隔离 下颌形态 几何形态测量学
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部