目的分析副溶血弧菌O10:K4血清型O抗原基因簇的分子特征,并构建基于基因组的分子血清型预测数据库。方法从美国国家生物技术信息中心Assembly数据库获取副溶血弧菌O抗原基因簇序列,使用blastn、fastANI、Sourmash和p i x y工具分析序列...目的分析副溶血弧菌O10:K4血清型O抗原基因簇的分子特征,并构建基于基因组的分子血清型预测数据库。方法从美国国家生物技术信息中心Assembly数据库获取副溶血弧菌O抗原基因簇序列,使用blastn、fastANI、Sourmash和p i x y工具分析序列相似性和多态性,使用g u b b i n s进行重组分析,并构建了副溶血弧菌分子血清型预测数据库。结果O10:K4的O抗原基因簇(OL10V1)与传统O10血清型基因簇(OL10)序列差异显著,而与OL4最为相似。公共数据库中116个OL10V1全长序列仅存在1个单核苷酸突变。OL10V1携带的IS1634和ISVa2转座酶基因广泛分布于弧菌属,提示该变异体可能通过水平基因转移形成。结论本研究揭示了O10:K4血清型快速传播的潜在分子机制,构建的分子血清型数据库可为基因组监测和溯源提供关键技术支撑。展开更多
Ce3+/Dy3+/Tb3+/Eu3+/Mn2+and Cr3+ions co-doped Zn3 Al2 Ge2 O10 phosphor were prepared by a hightemperature solid-state method.X-ray diffraction patterns prove the cubic phase structure of prepared Zn3 Al2 Ge2 O10 phosp...Ce3+/Dy3+/Tb3+/Eu3+/Mn2+and Cr3+ions co-doped Zn3 Al2 Ge2 O10 phosphor were prepared by a hightemperature solid-state method.X-ray diffraction patterns prove the cubic phase structure of prepared Zn3 Al2 Ge2 O10 phosphor,Emission,excitation spectra and decay curves confirm the tunable luminescence.Different degrees of the decrease of emission FWHM in Zn3 Al2 Ge2 O10:0.02 Cr3+,RE(RE=Ce3+,Dy3+,Tb3+,Eu3+)and Zn3 Al2 Ge2 O10:0.02 Cr3+,Mn2+are observed.The reason of variable FWHM is the effect of crystal field splitting and nephelauxetic effect,and the nephelauxetic effect is dominant.Therefore,the emission FWHM decreases with the increasing concentration of Mn2+/Tb3+/Eu3+in Zn3 Al2 Ge2 O10:0.02 Cr3+,and for Zn3 Al2 Ge2 O10:0.02 Cr3+,Ce3+and Zn3 Al2 Ge2 O10:0.02 Cr3+,Dy3+,it is a constant.The variation of Zn3 Al2 Ge2 O10:0.02 Cr3+,Tb3+is more obvious than that of Zn3 Al2 Ge2 O10:0.02 Cr3+,Eu3+,because Tb3+ion has smaller electronegativity.Thus,the tunable luminescence of Cr3+can be realized by co-doping different ions.And these phosphors have potential applications in light-emitting diodes for plant growth.展开更多
In the continuation of our study on the Serratta marcescens O-antigen, two disaccharides8 and 13, corresponding to the key intermediates of oligosaccharides related to the S. marcescensO10 antigen, were srythesized by...In the continuation of our study on the Serratta marcescens O-antigen, two disaccharides8 and 13, corresponding to the key intermediates of oligosaccharides related to the S. marcescensO10 antigen, were srythesized by the trichloroacetate method. Their structures and compositionswere characterized by H NMR, C NMR, 2D NMR and IR, FAB-MS spectra.展开更多
During a 2018 antimicrobial resistance surveillance of Escherichia coli isolates from diarrheal calves in Xinjiang Province,China,an unexpectedly high prevalence(48.5%)of fosfomycin resistance was observed.This study ...During a 2018 antimicrobial resistance surveillance of Escherichia coli isolates from diarrheal calves in Xinjiang Province,China,an unexpectedly high prevalence(48.5%)of fosfomycin resistance was observed.This study aimed to reveal the determinants of fosfomycin resistance and the underlying transmission mechanism.Polymerase chain reaction(PCR)screening showed that all fosfomycin-resistant E.coli carried the fosA3 gene.Pulsed-field gel electrophoresis(PFGE)and southern blot hybridization revealed that the 16 fosA3-positive isolates belonged to four different PFGE patterns(i.e.,A,B,C,D).The fosA3 genes of 11 clonally related strains(pattern D)were located on the chromosome,while others were carried by plasmids.Whole-genome and long-read sequencing indicated that the pattern D strains were E.coli O101:H9-ST10,and the pattern C,B,and A strains were O101:H9-ST167,O8:H30-ST1431,and O101:H9 with unknown ST,respectively.Among the pattern C strains,the blaCTX-M-14 gene was co-localized with the fosA3 gene on the F18:A-:B1 plasmids.Interestingly,phylogenetic analysis based on core genome single nucleotide polymorphisms(cgSNPs)showed that the O101:H9-ST10 strains were closely related to a Australian-isolated Chroicocephalus-origin E.coli O101:H9-ST10 strain producing CTX-M-14 and FosA3,with a difference of only 11 SNPs.These results indicate possible international dissemination of the high-risk E.coli clone O101:H9-ST10 by migratory birds.展开更多
Tl2Ba2Ca2Cu3O10 was reported to be a superconductor with a highest transition temperature of 125 K among the homologous series of Tl2Ba2Can-1CunO2n＋4. The direct information on the Cu ion site at the atomic level is ...Tl2Ba2Ca2Cu3O10 was reported to be a superconductor with a highest transition temperature of 125 K among the homologous series of Tl2Ba2Can-1CunO2n＋4. The direct information on the Cu ion site at the atomic level is important for elucidating the superconductivity mechanism. The local bond properties of Tl2Ba2Ca2Cu3O10 were studied using the average band-gap model. The calculated results show that the covalency of Cu（1）-O bond is 0.561, and the average covalency of Cu（2）-O is 0.296. Mossbauer isomer shifts of 57Fe in Tl2Ba2Ca2Cu3O10 were calculated using the chemical surrounding factor, defined by covalency and electronic polarizability. It is verified that for lower doping, Fe substitute the Cu at the Cu （1） site in forms of Fe^3＋ and Fe^4＋; for higher doping, Fe^3＋ and Fe^4＋ ion occupies Cu（1） and Cu（2） site respectively. The studies show that the determination of the correspondence between spectrum components and actual copper sites occupied by MSssbauer nucleus was made easier with the aid of the calculation results of the chemical bond parameters.展开更多
文摘目的分析副溶血弧菌O10:K4血清型O抗原基因簇的分子特征,并构建基于基因组的分子血清型预测数据库。方法从美国国家生物技术信息中心Assembly数据库获取副溶血弧菌O抗原基因簇序列,使用blastn、fastANI、Sourmash和p i x y工具分析序列相似性和多态性,使用g u b b i n s进行重组分析,并构建了副溶血弧菌分子血清型预测数据库。结果O10:K4的O抗原基因簇(OL10V1)与传统O10血清型基因簇(OL10)序列差异显著,而与OL4最为相似。公共数据库中116个OL10V1全长序列仅存在1个单核苷酸突变。OL10V1携带的IS1634和ISVa2转座酶基因广泛分布于弧菌属,提示该变异体可能通过水平基因转移形成。结论本研究揭示了O10:K4血清型快速传播的潜在分子机制,构建的分子血清型数据库可为基因组监测和溯源提供关键技术支撑。
基金Projects supported by the National Natural Science Foundation of China(61575019,11474018,61775013),ChinaThe authors express the thanks to the Fundamental ResearchFunds for the Central Universities under Grant No. 2018YJS166,China and the Fundamental Research Funds for the Central Universitieswith the Grant No. 2016JBM066,No. 2017RC015, No.2017JBZ105, China.
文摘Ce3+/Dy3+/Tb3+/Eu3+/Mn2+and Cr3+ions co-doped Zn3 Al2 Ge2 O10 phosphor were prepared by a hightemperature solid-state method.X-ray diffraction patterns prove the cubic phase structure of prepared Zn3 Al2 Ge2 O10 phosphor,Emission,excitation spectra and decay curves confirm the tunable luminescence.Different degrees of the decrease of emission FWHM in Zn3 Al2 Ge2 O10:0.02 Cr3+,RE(RE=Ce3+,Dy3+,Tb3+,Eu3+)and Zn3 Al2 Ge2 O10:0.02 Cr3+,Mn2+are observed.The reason of variable FWHM is the effect of crystal field splitting and nephelauxetic effect,and the nephelauxetic effect is dominant.Therefore,the emission FWHM decreases with the increasing concentration of Mn2+/Tb3+/Eu3+in Zn3 Al2 Ge2 O10:0.02 Cr3+,and for Zn3 Al2 Ge2 O10:0.02 Cr3+,Ce3+and Zn3 Al2 Ge2 O10:0.02 Cr3+,Dy3+,it is a constant.The variation of Zn3 Al2 Ge2 O10:0.02 Cr3+,Tb3+is more obvious than that of Zn3 Al2 Ge2 O10:0.02 Cr3+,Eu3+,because Tb3+ion has smaller electronegativity.Thus,the tunable luminescence of Cr3+can be realized by co-doping different ions.And these phosphors have potential applications in light-emitting diodes for plant growth.
文摘In the continuation of our study on the Serratta marcescens O-antigen, two disaccharides8 and 13, corresponding to the key intermediates of oligosaccharides related to the S. marcescensO10 antigen, were srythesized by the trichloroacetate method. Their structures and compositionswere characterized by H NMR, C NMR, 2D NMR and IR, FAB-MS spectra.
基金supported by the National Natural Science Foundation of China(31625026)International Science and Technology Cooperation Project of Xinjiang Production and Construction Corps(XPCC)(2019BC004)Innovation Team Project of Guangdong University(2019KCXTD001)。
文摘During a 2018 antimicrobial resistance surveillance of Escherichia coli isolates from diarrheal calves in Xinjiang Province,China,an unexpectedly high prevalence(48.5%)of fosfomycin resistance was observed.This study aimed to reveal the determinants of fosfomycin resistance and the underlying transmission mechanism.Polymerase chain reaction(PCR)screening showed that all fosfomycin-resistant E.coli carried the fosA3 gene.Pulsed-field gel electrophoresis(PFGE)and southern blot hybridization revealed that the 16 fosA3-positive isolates belonged to four different PFGE patterns(i.e.,A,B,C,D).The fosA3 genes of 11 clonally related strains(pattern D)were located on the chromosome,while others were carried by plasmids.Whole-genome and long-read sequencing indicated that the pattern D strains were E.coli O101:H9-ST10,and the pattern C,B,and A strains were O101:H9-ST167,O8:H30-ST1431,and O101:H9 with unknown ST,respectively.Among the pattern C strains,the blaCTX-M-14 gene was co-localized with the fosA3 gene on the F18:A-:B1 plasmids.Interestingly,phylogenetic analysis based on core genome single nucleotide polymorphisms(cgSNPs)showed that the O101:H9-ST10 strains were closely related to a Australian-isolated Chroicocephalus-origin E.coli O101:H9-ST10 strain producing CTX-M-14 and FosA3,with a difference of only 11 SNPs.These results indicate possible international dissemination of the high-risk E.coli clone O101:H9-ST10 by migratory birds.
文摘Tl2Ba2Ca2Cu3O10 was reported to be a superconductor with a highest transition temperature of 125 K among the homologous series of Tl2Ba2Can-1CunO2n＋4. The direct information on the Cu ion site at the atomic level is important for elucidating the superconductivity mechanism. The local bond properties of Tl2Ba2Ca2Cu3O10 were studied using the average band-gap model. The calculated results show that the covalency of Cu（1）-O bond is 0.561, and the average covalency of Cu（2）-O is 0.296. Mossbauer isomer shifts of 57Fe in Tl2Ba2Ca2Cu3O10 were calculated using the chemical surrounding factor, defined by covalency and electronic polarizability. It is verified that for lower doping, Fe substitute the Cu at the Cu （1） site in forms of Fe^3＋ and Fe^4＋; for higher doping, Fe^3＋ and Fe^4＋ ion occupies Cu（1） and Cu（2） site respectively. The studies show that the determination of the correspondence between spectrum components and actual copper sites occupied by MSssbauer nucleus was made easier with the aid of the calculation results of the chemical bond parameters.
