A complete sequence and comparative analysis of a SARS-associated virus （Isolate BJO1）

The genome sequence of the Severe Acute Respiratory Syndrome (SARS)-assoclated virus provides essential information for the identification of pathogen(s), exploration of etiology and evolution, interpretation of transmission and pathogenesis, development of diagnostics, prevention by future vaccination, and treatment by developing new drugs.We report the complete genome sequence and comparative analysis of an isolate (B J01) of the coronavirus that has been recognized as a pathogen for SARS. The genome is 29725 nt in size and has 11 ORFs (Open Reading Frames). It is composed of a stable region encoding an RNA-dependent RNA polymerase (composed of 20RFs) and a variable region representing 4 CDSs (coding sequences) for viral structural genes (the S, E, M, N proteins) and 5 PUPs (putative uncharacterized proteins). Its gene order is identical to that of other known coronaviruses. The sequence alignment with all known RNA viruses places this virus as a member in the family of Coronaviridae. Thirty putative substitutions have been identified by comparative analysis of the 5 SARS-associated virus genome sequences in GenBank. Fifteen of them lead to possible amino acid changes (non-synonymous mutations) in the proteins. Three amino acid changes, with predicted alteration of physical and chemical features, have been detected in the S protein that is postulated to be involved in the immunoreactions between the virus and its host.Two amino acid changes have been detected in the M protein,which could be related to viral envelope formation. Phylogenetic analysis suggests the possibility of non-human origin of the SARS-associated viruses but provides no evidence that they are man-made. Further efforts should focus on identifying the etiology of the SARS-associated virus and ruling out conclusively the existence of other possible SARS-related pathogen(s).     

SARS相关冠状病毒刺突糖蛋白的研究(综述)

概述了SARS—CoV的S蛋白的结构及功能相关研究。严重急性呼吸综合症相关的冠状病毒(SARS-CoV)引起2003年我国南方非典型肺炎爆发流行,波及多个国家和地区。目前全球许多学对SARS-CoV进行了广泛的研究,发现S蛋白是病毒表面的主要蛋白,它构成冠状病毒科特征性的冠状样结构,在严重急性呼吸综合症的发病机制起着关键性作用,可介导表达相关受体的宿主细胞感染。现已鉴定出SARS-CoV的S蛋白相关受体,同时它在抗病毒感染中是一个关键靶蛋白。     

SARS冠状病毒的基因组结构与药物治疗

介绍了SAPS冠状病毒的基因组结构及其作用机制的最新研究进展，探讨了抗SARS病毒药物的研制。     

Genome sequencing and characterization analysis of a Beijing isolate of chicken coronavirus infectious bronchitis virus

Avian infectious bronchitis virus (AIBV) is classified as a member of the genus coronavirus in the family coronaviridae. The enveloped virus has a positive-sense, single-stranded RNA genome of approximately 28 kilo-bases,which has a 5‘ cap structure and 3‘ polyadenylation tract.The complete genome sequence of infectious bronchitis virus (IBV), Beijing isolate, was determined by cloning sequencing and primer walking. The whole genome is 27733 nucleotides in length, has ten open reading frames:5′-orfla-orflab-s-3a-3b-e-m- 6a-6b-n-3′. Alignments of the genome sequence of IBV Beijing isolate with those of two AIBV strains and one SARS coronavirus were performed respectively. The genome sequence of IBV Beijing isolate compared with that of the IBV strain LX4 (uncompleted, 19440 bp in size) was 91.2% similarity. However, the full-length genome sequence of IBV Beijing isolate was 85.2% identity to that of IBV Strain Beaudette, and was only 50.8% homology to that of SARS coronavirus. The results showed that the genome of IBV has remarkable variation. And IBV Beijing isolate is not closely related to SARS coronavirus. Phylogenetic analyses based on the whole genome sequence, S protein, M protein and N protein, also showed that AIBV Bering isolate is lone virus in group Ⅲ and is distant from SARS coronavirus. In conclusion, this study will contribute to the studies of diagnosis and diseases control on IBV in China.     

六种蝗虫基因组DNA多态性的RAPD标记研究

运用随机扩增多态 DNA技术对斑翅蝗科 Oedipodidae中三属六种蝗虫基因组DNA进行了多态性比较 ,共扩增出 2 2条特异性片断 ,分子量大小为 650～ 1 990 bp之间 ,并根据各种间片段共享度构建了 UPG聚类关系图 .研究结果表明 ,大垫尖翅蝗和甘蒙尖翅蝗的片段共享度为 0 .375;红翅皱膝蝗和鼓翅皱膝蝗的片段共享度为 0 .2 86;亚洲小车蝗和黄胫小车蝗的片段共享度也为 0 .2 86     

Measles virus (Nepal strain) hemagglutinin gene: Cloning, complete nucleotide sequence analysis and expression in COS cells

Hemagglutinin gene of Measles virus(Nepal strain) was amplified by RT-PCR technique, cloned and sequenced by the dideoxy-mediated chain termination method. The comparison to the standard strain (Edmonston strain) showed many important mutations. The homology of these two strains was 98.17%. Then H gene was cloned into expression vector pCD-SRα296 and introduced into COS-7 cells by electroporation method. The expression and function of cloned H gene was checked by hemadsorption assays. Supported by company of microbial diseases, Osaka university, Japan Li Lingyun: born in sept. 1967. Ph. D, Graduate student     

慢性粒细胞白血病先后急性变M_(2a),M_(2b)例

目的　追踪观察患者慢性粒细胞白血病(CML)双重急性变(M2a,M2b)的诊断及治疗过程,以期对慢粒急变有更深入的了解.方法　对患者整个病程给予追踪记录.结果与结论　通过对患者病程的诊断、治疗和观察,进一步研究和探讨慢性粒细胞白血病急性变机制及基因、染色体的结构变化.     

对虾白斑综合症病毒P9蛋白转录水平的微阵列分析及其免疫荧光标记

从构建的对虾白斑综合症病毒cDNA文库中,我们筛选到一个拷贝数最高,编码82个氨基酸的基因(命名为p9,wsv230).该基因被克隆到pGEX-2T载体中进行GST融合蛋白的原核表达,纯化的融合蛋白GST-P9用于制备特异的多克隆抗体.利用微阵列技术和免疫荧光标记技术,对该蛋白的转录水平及其在感染细胞内的分布进行了初步研究,表明该基因为高丰度表达,推测是对虾白斑综合症病毒的一个重要基因.     

锯缘青蟹一种球状病毒的分离和组织病理观察

从患病锯缘青蟹组织中分离出一种无囊膜球状病毒,直径50~60 nm.通过病理切片观察,病蟹肝胰腺、肌肉、心脏、肠和鳃等多处组织器官受到感染,该病毒分布在细胞浆中,呈晶格状排列,不形成包涵体;这种病毒会导致细胞瓦解,细胞核肿大变形,核质聚缩,核膜破损,肌丝断裂,线粒体坏死等症状.     

瞬态诱发耳声发射信号近似熵的分析及应用

为研究有无对侧刺激声 (CAS)作用下 ,瞬态诱发耳声发射 (TEOAE)信号的变化特征 ,根据耳蜗的非线性特性 ,提出了将近似熵的分析方法引入到耳声发射信号的研究中 ,并将近似熵的分析方法从时间序列复杂性的度量中引入到频率序列复杂性的度量中。结果表明 :无 CAS作用下 ,TEOAE频域信号的近似熵在各频带处 ,蜗性病变耳的近似熵明显低于正常耳的近似熵 ,蜗后病变耳的近似熵与正常耳的近似熵无明显差别。在 CAS作用下 ,听力正常耳的近似熵下降 ,而感音神经性耳聋的近似熵上升 ,且近似熵上升的频带与耳蜗或蜗后神经患病处频带相关 .根据研究结果 ,提出了利用有无对侧刺激声作用下耳声发射信号近似熵的变化来诊断感音神经性耳聋的方法     

天葵几种粗提物对菜青虫、小菜蛾的拒食活性筛选

本文研究报道了天葵几种粗提物对菜青虫、小菜蛾的拒食活性筛选。经石油醚、氯仿、丙酮粗提物的拒食活性比较,结果表明石油醚粗提物的拒食效果较好,石油醚粗提物经进一步分离得油状和结晶粗提物,二者经拒食活性比较,结果表明石油醚油状粗提物的活性较强。     

铁路列调弱场区无线中继通信抑制同频干扰的对策

为保证铁路列调磁场区无线中继通信系统的通信质量,分析了该我线中继系统产生同频干扰的机理,提出了抑制同频干扰的有效对策,经现场试验证明方案可行。     

中国食虫虻一新种及二种国内新记录(双翅目:食虫虻科)

在整理中山大学昆虫研究所保存的食虫虻标本时,发现克虫虻属Clephydroneura Becker,1925一新种及一中国新记录和钉突虫虻属Euscelidia Westwood,1849一中国新记录,现报道如下.模式标本保存于中山大学昆虫学研究所标本室. 海南克虫虻 Clephydroneura hainanensis新种(图1) 雄虫体长18毫米,翅长13毫米.     

Expressed sequence tags analysis revealing the taxonomic position and fatty acid biosynthesis in an oleaginous green microalga, Myrmecia incisa Reisigl (Trebouxiophyceae, Chlorophyta)

cDNA library of Myrmecia incisa H4301 was constructed using λ phage vectors.The library consisted of 1.5×10 6 clones with a recombination rate of 90%,and 1942 clones were randomly sequenced.All 1854 readable expressed sequence tags(ESTs) were clustered into 596 non-redundant sequences(NRSs),among which 126 NRSs were from 1384 ESTs,showing a high redundancy.Among the 596 NRSs,30 were ribosomal RNA,and 152 significantly matched with those available in NCBI database and JGI Genome Portal,the latter were divided into nine subcategories.Overall,59 NRSs were involved in photosynthesis,the respiratory electron transport chain,ATP synthesis,oxidation reduction,fatty acid biosynthesis,glucose metabolism,protein metabolism,and small molecular metabolism,suggesting that these genes were abundantly transcribed during energy and substance metabolism.Acyl-carrier protein,ferrodoxin and fatty acid elongase genes obtained from this cDNA library enabled presumption of a possible biosynthesis pathway of ArA in M.incisa.Codon usage analysis of 142 NRSs with 17798 codons in the predicted coding regions showed that the average G+C content level of the total codons was 55.39%,and that of the third position in base trimers was 66.42%,indicating a strong bias toward cytosine and/or guanosine in this algal genome.Among all synonymous codons,NAG was most favored,while NUA was most avoided.Phylogenic trees inferred from ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit genes and the extra partial sequences of 18S rRNA obtained from this library demonstrated that M.incisa belonged to Trebouxiophyceae and was significantly clustered with M.incisa SAG 2007,Lobosphaera tirolensis,M.bisecta,and Parietochloris incisa,but was clearly distant from P.pseudoalveolaris and P.alveolar.Transmission electron microscopy revealed pyrenoids traversed by many parallel thylakoids membranes,while starch grains were only clearly observed when cells were grown under nitrogen stress.Based on combined investigation of the phylogeny and morphological characteristics,it is proposed that M.incisa be kept in the genus Myrmecia in which there might be two parallel groups,one living freely and another symbiotic species.     

泛函临界值的一个充要条件

该文得到了泛函临界值存在的一个充分条件，研究了渐近最小值渐近临界值之间的关系，同时把所结果应用于不动点理论，给出了若干弱内映象的不动点定理。     

简化沸水堆(SSBWR-200)的热工设计和事故分析

设计开发了新一代小型先进简化沸水堆— SSBWR-2 0 0。采用全功率自然循环、较低的功率密度、堆芯以上更大的冷却剂装量、新型的水力学控制棒传动系统、非能动余热载出系统以及取消堆芯紧急冷却系统、安全壳冷却及喷淋系统等先进设计。通过引入反应性扰动以及对 6种典型事故的计算分析 ,结果表明 :SSBWR- 2 0 0具有良好的稳定性和安全性 ,可以应用于热电联供、区域供热、海水淡化等多种目的     

聚酯熔体的5参数流变模型

采用旋转流变仪锥板系统，对聚对苯二甲酸乙二醇酯（简称聚酯或ＰＥＴ）熔体的流变特性进行了研究。测定温度为２７０～２９０℃，得到５种聚酯试样的剪切速率γ、剪切应力和正应力ψ＿１的数据。聚酯熔体表观粘度η、ψ＿１随γ增加而减小，具有剪切变稀的性质。在Ｏｌｄｒｏｙｄ４参数模型的基础上，考虑聚酯熔体的幂律性质，提出了５参数模型。结果可供聚酯加工成型工艺过程和模具设计时参考。     

四川黑熊ND3、ND4L和tRNA-Arg基因的克隆和序列分析

克隆并测定了四川黑熊（Ursus thibetanus mupinensis）线粒体基因组764 bp的片段,根据序列同源性比较,该DNA片段包括2个蛋白质编码基因：ND3和ND4L基因,以及1个tRNA-Arg基因.四川黑熊的ND3基因和ND4L基因的DNA序列和所编码的氨基酸序列与马来熊、棕熊、美洲黑熊和北极熊的同源性分别为：90%和95%、93%和97%、91%和96%、93%和97%;89%和98.98%、88%和98.98%、89%和100%、89%和98.98%.与棕熊、美洲黑熊和北极熊tRNA-Arg（CGA）的同源性分别为95.65%、94.20%和94.20%.拓扑结构比较显示,四川黑熊的ND3基因所编码的氨基酸序列比美洲黑熊的少了1个蛋白激酶C磷酸化位点.     

C_（60）及其衍生物国内外研究概况

介绍了Ｃ_（６０）的发现过程、制造方法，Ｃ_（６０）及其衍生物的物理、化学性能以及有关Ｃ_（６０）的国内外研究状况。     

Sequence analysis of the gene correlated with cytoplasmic male sterility (CMS) in rape-seed (Brassica napus) Polima and Shaan 2A

orf224 is a CMS-related mitochondrial gene discovered in Polima cytoplasm. Shaan 2A CMS line is the parent of the first rapeseed hybrid cultivar Qinyou No. 2 that has been grown in many regions of China. In this work, genomic DNA of Polima CMS line and Shaan 2A CMS line were used as templates, two primers of specific oligonucleotides at 5′ and 3′ ends were used, PCR was performed, the amplification fragments were cloned into pGEM-T Easy vectors and DNA sequences were determined. The CMS-associated gene, orf224-1 present in Shaan 2A CMS line, has a sequence highly homologous to the orf224 of the Polima CMS line, except for one nucleotide at position +398. There were only one base (AAC→AGC) and one amino acid (Asn →Ser) differences between the two. The homologies of the two sequences in nucleotide and amino acid were 99.9% and 99.6%, respectively. It is concluded that orf224 in Polima CMS line and orf224-1 of Shaan 2A CMS line are the allele at the same locus in mitochondria.