The complete nucleotide sequence of genomic RNA of foot and mouth disease virus (FMDV) strain China/99 from infected bovine tongue epithelium is presented. The nucleotide sequence extending from the 5′ end of the gen...The complete nucleotide sequence of genomic RNA of foot and mouth disease virus (FMDV) strain China/99 from infected bovine tongue epithelium is presented. The nucleotide sequence extending from the 5′ end of the genomic RNA to the 5′ end of poly (A) tail contains 8173 nucleotides (nt). Its open reading frame, which encodes a single polypeptide of 2332 amino acids, encompasses 6999 nt starting from the initiation codon AUG and terminating at the UAA codon 93 bases upstream from the 5′ end of poly (A) tract. The 5′ untranslated region (UTR) is composed of 1081nt. The consensus of the 1d gene of FMDV strain China/99 compared with that of UKG/6/2001, UKG/12/2001, China/99HN4 and China/3/Tibet is over 97%. The result showed the stains belong to the members of the Pan-Asia family. There is a remarkable differentiation in the function-unknown (FUR), p2 and p3 regions between FMDV isolates from infected cattle and swine, especially in 3a gene. No deletion was found in genes l, 1a, 1b, 2a, 2c, 3b, and 3d. These genes might be indispensable to the surviving of FMDV. The secondary structures of small (S) fragments, FUR and an internal ribosome entry site can be classified into three types, and the S fragment and 3′UTR of the positive-sense RNA fold into stem-loop structures similar to the shape of clover.展开更多
医用同位素锝-99m(99mTc)被广泛应用于核医学领域,其主要来源于母体核素钼-99(99Mo)的衰变。但是目前国内99Mo基本依赖进口,通常出现99Mo不能稳定供应的现象。为解决这个重大问题,实现国内99Mo自主化生产具有重要意义。本文基于中国科...医用同位素锝-99m(99mTc)被广泛应用于核医学领域,其主要来源于母体核素钼-99(99Mo)的衰变。但是目前国内99Mo基本依赖进口,通常出现99Mo不能稳定供应的现象。为解决这个重大问题,实现国内99Mo自主化生产具有重要意义。本文基于中国科学院近代物理研究所强流超导直线加速器(China ADS Front End,CAFE)提供的质子束流辐照天然铀靶件,主要开展铀裂变产物中医用同位素99Mo的高效化学分离、纯化及99Mo/99mTc发生器的制备。研究表明:通过α-安息香肟(α-BO)沉淀分离99Mo后,杂质核素去除率大于90%,99Mo的回收率大于90%。通过对99Mo沉淀进行纯化后,大部分杂质核素被去除。提取的99Mo被装配为99Mo/99mTc发生器,发生器淋洗曲线表明:99mTc产品收集在8 mL生理盐水内最为适宜,同时,99mTc回收率大于80%。电感耦合等离子体发射光谱仪(ICP-OES)测量结果表明,99mTc产品中Al、Mo以及U含量极低;同时,99mTc产品的γ谱图中未出现99Mo和其他杂质核素的γ能量峰。以上研究结果可为国内基于加速器辐照天然铀生产99Mo提供技术参考。展开更多
文摘The complete nucleotide sequence of genomic RNA of foot and mouth disease virus (FMDV) strain China/99 from infected bovine tongue epithelium is presented. The nucleotide sequence extending from the 5′ end of the genomic RNA to the 5′ end of poly (A) tail contains 8173 nucleotides (nt). Its open reading frame, which encodes a single polypeptide of 2332 amino acids, encompasses 6999 nt starting from the initiation codon AUG and terminating at the UAA codon 93 bases upstream from the 5′ end of poly (A) tract. The 5′ untranslated region (UTR) is composed of 1081nt. The consensus of the 1d gene of FMDV strain China/99 compared with that of UKG/6/2001, UKG/12/2001, China/99HN4 and China/3/Tibet is over 97%. The result showed the stains belong to the members of the Pan-Asia family. There is a remarkable differentiation in the function-unknown (FUR), p2 and p3 regions between FMDV isolates from infected cattle and swine, especially in 3a gene. No deletion was found in genes l, 1a, 1b, 2a, 2c, 3b, and 3d. These genes might be indispensable to the surviving of FMDV. The secondary structures of small (S) fragments, FUR and an internal ribosome entry site can be classified into three types, and the S fragment and 3′UTR of the positive-sense RNA fold into stem-loop structures similar to the shape of clover.
文摘医用同位素锝-99m(99mTc)被广泛应用于核医学领域,其主要来源于母体核素钼-99(99Mo)的衰变。但是目前国内99Mo基本依赖进口,通常出现99Mo不能稳定供应的现象。为解决这个重大问题,实现国内99Mo自主化生产具有重要意义。本文基于中国科学院近代物理研究所强流超导直线加速器(China ADS Front End,CAFE)提供的质子束流辐照天然铀靶件,主要开展铀裂变产物中医用同位素99Mo的高效化学分离、纯化及99Mo/99mTc发生器的制备。研究表明:通过α-安息香肟(α-BO)沉淀分离99Mo后,杂质核素去除率大于90%,99Mo的回收率大于90%。通过对99Mo沉淀进行纯化后,大部分杂质核素被去除。提取的99Mo被装配为99Mo/99mTc发生器,发生器淋洗曲线表明:99mTc产品收集在8 mL生理盐水内最为适宜,同时,99mTc回收率大于80%。电感耦合等离子体发射光谱仪(ICP-OES)测量结果表明,99mTc产品中Al、Mo以及U含量极低;同时,99mTc产品的γ谱图中未出现99Mo和其他杂质核素的γ能量峰。以上研究结果可为国内基于加速器辐照天然铀生产99Mo提供技术参考。
