Background:SARS-CoV-2,first identified in late 2019,has given rise to numerous variants of concern(VOCs),posing a significant threat to human health.The emer-gence of Omicron BA.1.1 towards the end of 2021 led to a pa...Background:SARS-CoV-2,first identified in late 2019,has given rise to numerous variants of concern(VOCs),posing a significant threat to human health.The emer-gence of Omicron BA.1.1 towards the end of 2021 led to a pandemic in early 2022.At present,the lethal mouse model for the study of SARS-CoV-2 needs supplementation,and the alterations in neutrophils and monocytes caused by different strains remain to be elucidated.Methods:Human ACE2 transgenic mice were inoculated with the SARS-CoV-2 proto-type and Omicron BA.1,respectively.The pathogenicity of the two strains was evalu-ated by observing clinical symptoms,viral load and pathology.Complete blood count,immunohistochemistry and flow cytometry were performed to detect the alterations of neutrophils and monocytes caused by the two strains.Results:Our findings revealed that Omicron BA.1 exhibited significantly lower vir-ulence compared to the SARS-CoV-2 prototype in the mouse model.Additionally,we observed a significant increase in the proportion of neutrophils late in infection with the SARS-CoV-2 prototype and Omicron BA.1.We found that the proportion of monocytes increased at first and then decreased.The trends in the changes in the proportions of neutrophils and monocytes induced by the two strains were similar.Conclusion:Our study provides valuable insights into the utility of mouse models for simulating the severe disease of SARS-CoV-2 prototype infection and the milder manifestation associated with Omicron BA.1.SARS-CoV-2 prototype and Omicron BA.1 resulted in similar trends in the changes in neutrophils and monocytes.展开更多
新型冠状病毒Omicron变异株出现之后,在全球暴发流行过程中不断进化出传播速度更快、免疫逃逸能力更强的进化分支,为了探究BA.1变异株在全球暴发流行的特征及刺突蛋白(Spike,S)基因的进化特征,本研究对其全基因序列的全球报告情况和S基...新型冠状病毒Omicron变异株出现之后,在全球暴发流行过程中不断进化出传播速度更快、免疫逃逸能力更强的进化分支,为了探究BA.1变异株在全球暴发流行的特征及刺突蛋白(Spike,S)基因的进化特征,本研究对其全基因序列的全球报告情况和S基因的进化特征进行了分析。本文通过全球共享流感数据倡议组织(Global Initiative of Sharing All Influenza Data,GISAID)获取Omicron BA.1系列变异株的全基因序列信息,分析BA.1系列变异株S基因氨基酸突变并构建系统进化树和进行贝叶斯系统进化分析。本研究提示全球约有1.2亿人被BA.1系列变异株感染,全球提交的BA.1系列变异株序列数在其出现2个月后达到高峰,5个月后占新型冠状病毒的比例下降到4.38%,累计提交BA.1全基因序列最多的区域是欧洲、美洲;截止2022年10月,BA.1系列变异株中序列提交数占绝对优势的是BA.1.1(42.07%),其次是BA.1(18.81%)。对S基因的氨基酸变异分析显示BA.1有56个进化分支,其中48个分支稳定遗传了Omicron原始株S蛋白中的18个氨基酸突变位点。对BA.1 S基因的进化分析显示其共同祖先形成时间(TMRCA)可追溯到2020年11月,S基因平均碱基替代速率为9.36×10^(-4)替换/位点/年,2021年3月BA.1流行过程中形成两个独立簇,推测G346K、G446S突变位点可能是提高病毒传播力的主要突变。本研究分析了BA.1系列变异株的流行及进化特征,其在短时间内迅速替代Delta毒株,成为全球绝对优势流行株,并有迅速被BA.2亚型代替的潜力。此外,BA.1在全球3~4个月的流行中,逐渐演变出56个进化分支,在全球流行时间短、出现部分稳定遗传的氨基酸突变、进化速率较快。因此,需密切关注Omicron系列变异株基因序列变异变迁、监测新增突变位点,及时研判新变异株的传播力、免疫逃逸能力和致病力。展开更多
Objective To investigate whether Omicron BA.1 breakthrough infection after receiving the SARS-CoV-2 vaccine could create a strong immunity barrier.Methods Blood samples were collected at two different time points from...Objective To investigate whether Omicron BA.1 breakthrough infection after receiving the SARS-CoV-2 vaccine could create a strong immunity barrier.Methods Blood samples were collected at two different time points from 124 Omicron BA.1 breakthrough infected patients and 124 controls matched for age,gender,and vaccination profile.Live virus-neutralizing antibodies against five SARS-CoV-2 variants,including WT,Gamma,Beta,Delta,and Omicron BA.1,and T-lymphocyte lymphocyte counts in both groups were measured and statistically analyzed.Results The neutralizing antibody titers against five different variants of SARS-CoV-2 were significantly increased in the vaccinated population infected with the Omicron BA.1 variant at 3 months after infection,but mainly increased the antibody level against the WT strain,and the antibody against the Omicron strain was the lowest.The neutralizing antibody level decreased rapidly 6 months after infection.The T-lymphocyte cell counts of patients with mild and moderate disease recovered at 3 months and completely returned to the normal state at 6 months.Conclusion Omicron BA.1 breakthrough infection mainly evoked humoral immune memory in the original strain after vaccination and hardly produced neutralizing antibodies specific to Omicron BA.1.Neutralizing antibodies against the different strains declined rapidly and showed features similar to those of influenza.Thus,T-lymphocytes may play an important role in recovery.展开更多
基于密度泛函理论的第一性原理计算研究了Ba1-xCaxTiO3(BCT,x=0,0.125,0.200,0.250,0.333,0.500)陶瓷的电子结构、介电、压电性及相关机理。研究发现,BCT陶瓷的带隙宽度随Ca2+掺杂量的增大先降后升,在x=0.125处取得最小值1.693 e V。光...基于密度泛函理论的第一性原理计算研究了Ba1-xCaxTiO3(BCT,x=0,0.125,0.200,0.250,0.333,0.500)陶瓷的电子结构、介电、压电性及相关机理。研究发现,BCT陶瓷的带隙宽度随Ca2+掺杂量的增大先降后升,在x=0.125处取得最小值1.693 e V。光子能量为0 e V时纯Ba Ti O3陶瓷的相对介电常数εr为5.957,在2.523 e V时εr达到峰值8.522。Ca2+掺杂量增大使其室温相对介电常数与介电损耗均减小,在x=0.500处,介电损耗在光子能量为3.447 e V时呈现峰值4.403。其态密度图谱表明原子之间的杂化使其压电性更稳定,其压电应变常数d33和压电应力常数e33在x=0.250处分别达到极大值99.8 p C/N和29.34 C/m2,微量Ca2+掺杂使Ba Ti O3陶瓷的室温压电性提高,两相共存区域正交相与四方相之间的耦合是其高压电性的关键因素。展开更多
Barium metaborate (BaB 2O 4) exists in two forms the high temperature for m α phase and the low temperature form β phase,with the phase transition poi nt at around 925℃.The low temperature phase (β BBO) is an exce...Barium metaborate (BaB 2O 4) exists in two forms the high temperature for m α phase and the low temperature form β phase,with the phase transition poi nt at around 925℃.The low temperature phase (β BBO) is an excellent NLO cryst al for UV region,while the high temperature one (α BBO) is known as a good bir efringent material.α BBO crystal possesses better transparency in the ultravio let region compared with commonly used YVO 4 and CaCO 3 crystals.However,due t o phase transition problem,it is difficult to grow single α BBO crystals by D CZ method,which restricts its wider application.α BBO crystal usually cracks upon cooling resulted from phase transition to β phase.Therefore,it is difficult to grow β BBO single crystals directly from pure BaB 2O 4 mel t;however,to grow single crystals of α BBO is not easy,either. Our recent experiments showed that one could avoid cracking of α BBO cryst als by Sr 2+ doping.This minute amount of Sr 2+ plays the role of structure stabilizer,which inhibits structural reconstruction. In this way,Sr 2+ d op ed BBO single crystals do not subject to phase transition from 925℃ down to roo m temperature. We have mow successfully grown out α BBO single crystals 30mm in diameter by D CZ method from Sr x Ba 1- x BO 4 melt with Sr concentration 0.3 0 .5%.The ratation rate is 10 15r/min,pulling speed is 1 2mm/h.Preliminary tests revealed that its structure and physic chemical properties were almost identic al to those grown from pure melts.These Sr 2+ doped α BBO crystals are no w being widely used in optical isolators.展开更多
基金supported by Beijing Natural Science Foundation(Grant No.Z210014)National Natural Science Foundation of China(Grant No.32070543)+1 种基金National Key Research and Development Project of China(Grant No.2022YFC2303404)CAMS Innovation Fund for Medical Sciences(CIFMS)(Grant No.2022-12M-CoV19-002)
文摘Background:SARS-CoV-2,first identified in late 2019,has given rise to numerous variants of concern(VOCs),posing a significant threat to human health.The emer-gence of Omicron BA.1.1 towards the end of 2021 led to a pandemic in early 2022.At present,the lethal mouse model for the study of SARS-CoV-2 needs supplementation,and the alterations in neutrophils and monocytes caused by different strains remain to be elucidated.Methods:Human ACE2 transgenic mice were inoculated with the SARS-CoV-2 proto-type and Omicron BA.1,respectively.The pathogenicity of the two strains was evalu-ated by observing clinical symptoms,viral load and pathology.Complete blood count,immunohistochemistry and flow cytometry were performed to detect the alterations of neutrophils and monocytes caused by the two strains.Results:Our findings revealed that Omicron BA.1 exhibited significantly lower vir-ulence compared to the SARS-CoV-2 prototype in the mouse model.Additionally,we observed a significant increase in the proportion of neutrophils late in infection with the SARS-CoV-2 prototype and Omicron BA.1.We found that the proportion of monocytes increased at first and then decreased.The trends in the changes in the proportions of neutrophils and monocytes induced by the two strains were similar.Conclusion:Our study provides valuable insights into the utility of mouse models for simulating the severe disease of SARS-CoV-2 prototype infection and the milder manifestation associated with Omicron BA.1.SARS-CoV-2 prototype and Omicron BA.1 resulted in similar trends in the changes in neutrophils and monocytes.
文摘新型冠状病毒Omicron变异株出现之后,在全球暴发流行过程中不断进化出传播速度更快、免疫逃逸能力更强的进化分支,为了探究BA.1变异株在全球暴发流行的特征及刺突蛋白(Spike,S)基因的进化特征,本研究对其全基因序列的全球报告情况和S基因的进化特征进行了分析。本文通过全球共享流感数据倡议组织(Global Initiative of Sharing All Influenza Data,GISAID)获取Omicron BA.1系列变异株的全基因序列信息,分析BA.1系列变异株S基因氨基酸突变并构建系统进化树和进行贝叶斯系统进化分析。本研究提示全球约有1.2亿人被BA.1系列变异株感染,全球提交的BA.1系列变异株序列数在其出现2个月后达到高峰,5个月后占新型冠状病毒的比例下降到4.38%,累计提交BA.1全基因序列最多的区域是欧洲、美洲;截止2022年10月,BA.1系列变异株中序列提交数占绝对优势的是BA.1.1(42.07%),其次是BA.1(18.81%)。对S基因的氨基酸变异分析显示BA.1有56个进化分支,其中48个分支稳定遗传了Omicron原始株S蛋白中的18个氨基酸突变位点。对BA.1 S基因的进化分析显示其共同祖先形成时间(TMRCA)可追溯到2020年11月,S基因平均碱基替代速率为9.36×10^(-4)替换/位点/年,2021年3月BA.1流行过程中形成两个独立簇,推测G346K、G446S突变位点可能是提高病毒传播力的主要突变。本研究分析了BA.1系列变异株的流行及进化特征,其在短时间内迅速替代Delta毒株,成为全球绝对优势流行株,并有迅速被BA.2亚型代替的潜力。此外,BA.1在全球3~4个月的流行中,逐渐演变出56个进化分支,在全球流行时间短、出现部分稳定遗传的氨基酸突变、进化速率较快。因此,需密切关注Omicron系列变异株基因序列变异变迁、监测新增突变位点,及时研判新变异株的传播力、免疫逃逸能力和致病力。
基金funded by the Emergency prevention and cure Program of COVID-19[22ZXGBSY00010]Tianjin Medical Key Discipline Project[TJYXZDXK-50A]sponsored by Tianjin Municipal Science and Technology Bureau and Tianjin Municipal Health Commission,respectively.
文摘Objective To investigate whether Omicron BA.1 breakthrough infection after receiving the SARS-CoV-2 vaccine could create a strong immunity barrier.Methods Blood samples were collected at two different time points from 124 Omicron BA.1 breakthrough infected patients and 124 controls matched for age,gender,and vaccination profile.Live virus-neutralizing antibodies against five SARS-CoV-2 variants,including WT,Gamma,Beta,Delta,and Omicron BA.1,and T-lymphocyte lymphocyte counts in both groups were measured and statistically analyzed.Results The neutralizing antibody titers against five different variants of SARS-CoV-2 were significantly increased in the vaccinated population infected with the Omicron BA.1 variant at 3 months after infection,but mainly increased the antibody level against the WT strain,and the antibody against the Omicron strain was the lowest.The neutralizing antibody level decreased rapidly 6 months after infection.The T-lymphocyte cell counts of patients with mild and moderate disease recovered at 3 months and completely returned to the normal state at 6 months.Conclusion Omicron BA.1 breakthrough infection mainly evoked humoral immune memory in the original strain after vaccination and hardly produced neutralizing antibodies specific to Omicron BA.1.Neutralizing antibodies against the different strains declined rapidly and showed features similar to those of influenza.Thus,T-lymphocytes may play an important role in recovery.
文摘基于密度泛函理论的第一性原理计算研究了Ba1-xCaxTiO3(BCT,x=0,0.125,0.200,0.250,0.333,0.500)陶瓷的电子结构、介电、压电性及相关机理。研究发现,BCT陶瓷的带隙宽度随Ca2+掺杂量的增大先降后升,在x=0.125处取得最小值1.693 e V。光子能量为0 e V时纯Ba Ti O3陶瓷的相对介电常数εr为5.957,在2.523 e V时εr达到峰值8.522。Ca2+掺杂量增大使其室温相对介电常数与介电损耗均减小,在x=0.500处,介电损耗在光子能量为3.447 e V时呈现峰值4.403。其态密度图谱表明原子之间的杂化使其压电性更稳定,其压电应变常数d33和压电应力常数e33在x=0.250处分别达到极大值99.8 p C/N和29.34 C/m2,微量Ca2+掺杂使Ba Ti O3陶瓷的室温压电性提高,两相共存区域正交相与四方相之间的耦合是其高压电性的关键因素。
文摘Barium metaborate (BaB 2O 4) exists in two forms the high temperature for m α phase and the low temperature form β phase,with the phase transition poi nt at around 925℃.The low temperature phase (β BBO) is an excellent NLO cryst al for UV region,while the high temperature one (α BBO) is known as a good bir efringent material.α BBO crystal possesses better transparency in the ultravio let region compared with commonly used YVO 4 and CaCO 3 crystals.However,due t o phase transition problem,it is difficult to grow single α BBO crystals by D CZ method,which restricts its wider application.α BBO crystal usually cracks upon cooling resulted from phase transition to β phase.Therefore,it is difficult to grow β BBO single crystals directly from pure BaB 2O 4 mel t;however,to grow single crystals of α BBO is not easy,either. Our recent experiments showed that one could avoid cracking of α BBO cryst als by Sr 2+ doping.This minute amount of Sr 2+ plays the role of structure stabilizer,which inhibits structural reconstruction. In this way,Sr 2+ d op ed BBO single crystals do not subject to phase transition from 925℃ down to roo m temperature. We have mow successfully grown out α BBO single crystals 30mm in diameter by D CZ method from Sr x Ba 1- x BO 4 melt with Sr concentration 0.3 0 .5%.The ratation rate is 10 15r/min,pulling speed is 1 2mm/h.Preliminary tests revealed that its structure and physic chemical properties were almost identic al to those grown from pure melts.These Sr 2+ doped α BBO crystals are no w being widely used in optical isolators.
