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
A new class of phosphor samples,denoted as Ba_(1-x)Al_(2)Ge_(2)O_(8):xEu^(2+)(BAGO:xEu^(2+))was synthesized using a Pechini-type sol-gel technique and subsequent thermal reduction in CO atmosphere.The morphology and s...A new class of phosphor samples,denoted as Ba_(1-x)Al_(2)Ge_(2)O_(8):xEu^(2+)(BAGO:xEu^(2+))was synthesized using a Pechini-type sol-gel technique and subsequent thermal reduction in CO atmosphere.The morphology and structural characteristics of both the BAGO host lattice and the Eu^(2+)ions activated BAGO phosphors were investigated through field-emission scanning electron microscopy and X-ray diffractometry analyses,respectively.The BAGO host lattice has micro-sized particles and the Rietveld refinement reveals the presence of a monoclinic crystal phase,characterized by the space group I2/c(No.15).Introducing Eu^(2+)ions into Ba^(2+)sites under CO condition reduces the particle size,switching from microscale to nanoscale.Within the near-ultraviolet spectrum(353 nm),the BAGO:xEu^(2+)phosphors exhibit a broadband bluish-green photoluminescence(PL)emission characterized by a peak band at 492 nm.This phenomenon is attributed to the 4f^(6)5d^(1)→4f^(7) electronic transition.The BAGO:0.02Eu^(2+)phosphor shows the strongest bluish-green PL emission,and a co mprehensive description of the concentration quenching mechanism between Eu^(2+)ions is revealed.Additionally,the thermal stability of the optimized BAGO:0.02Eu^(2+)phosphor was investigated,and its activation energy was estimated.Therefore,the synthesized bluish-green BAGO:0.02Eu^(2+)phosphor holds the promise of being a novel and potential candidate for utilization in white light-emitting diode applications.展开更多
The SARS-CoV-2 Omicron variants are notorious for their transmissibility,but little is known about their subgenomic RNA(sgRNA)expression.This study applied RNA-seq to delineate the quantitative and qualitative profile...The SARS-CoV-2 Omicron variants are notorious for their transmissibility,but little is known about their subgenomic RNA(sgRNA)expression.This study applied RNA-seq to delineate the quantitative and qualitative profiles of canonical sgRNA of 118 respiratory samples collected from patients infected with Omicron BA.2 and compared with 338 patients infected with non-variant of concern(non-VOC)-D614G.A unique characteristic profile depicted by the relative abundance of 9 canonical sgRNAs was reproduced by both BA.2 and non-VOCD614G regardless of host gender,age and presence of pneumonia.Remarkably,such profile was lost in samples with low viral load,suggesting a potential application of sgRNA pattern to indicate viral activity of individual patient at a specific time point.A characteristic qualitative profile of canonical sgRNAs was also reproduced by both BA.2 and non-VOC-D614G.The presence of a full set of canonical sgRNAs carried a coherent correlation with crude viral load(AUC¼0.91,95%CI 0.88–0.94),and sgRNA ORF7b was identified to be the best surrogate marker allowing feasible routine application in characterizing the infection status of individual patient.Further potentials in using sgRNA as a target for vaccine and antiviral development are worth pursuing.展开更多
The SARS-CoV-2 virus,particularly the Omicron BA.2 variant,led to a significant surge in Shanghai,2022.However,the viral load dynamic in Omicron infections with varying clinical severities remain unclear.This prospect...The SARS-CoV-2 virus,particularly the Omicron BA.2 variant,led to a significant surge in Shanghai,2022.However,the viral load dynamic in Omicron infections with varying clinical severities remain unclear.This prospective cohort included 48,830 hospitalized coronavirus disease 2019(COVID-19)patients across three hospitals in Shanghai,China,between 23 March and 15 May,2022.Systematic nucleic acid testing was performed using RT-PCR Cycle threshold(Ct)value as a proxy of viral load.We analyzed the kinetic characteristics of viral shedding by clinical severity and identified associated risk factors.The study comprised 31.06%asymptomatic cases,67.66%mild-moderate cases,1.00%severe cases,0.29%critical and fatal cases.Upon admission,57%of patients tested positive,with peak viral load observed at 4 days(median Ct value 27.5),followed by a decrease and an average viral shedding time(VST)of 6.1 days(Interquartile range,4.0–8.8 days).Although viral load exhibited variation by age and clinical severity,peak Ct values occurred at similar times.Unvaccinated status,age exceeding 60,and comorbidities including hypertension,renal issues kidney dialysis and kidney transplantation,neurological disorders,rheumatism,and psychotic conditions were found to correlate with elevated peak viral load and extended VST.Asymptomatic cases demonstrated a 40%likelihood of contagiousness within 6 days of detection,while mild-moderate and severe cases exhibited post-symptom resolution infectious probabilities of 27%and over 50%,respectively.These findings revealed that the initial Ct values serve as a predictive indicator of severe outcomes.Unvaccinated elderly individuals with particular comorbidities are at high-risk for elevated viral load and prolonged VST.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.
基金Project supported by the National Research Foundation of Korea Grant funded by the Korean government(MSIP)(2018R1A6A1A03025708)。
文摘A new class of phosphor samples,denoted as Ba_(1-x)Al_(2)Ge_(2)O_(8):xEu^(2+)(BAGO:xEu^(2+))was synthesized using a Pechini-type sol-gel technique and subsequent thermal reduction in CO atmosphere.The morphology and structural characteristics of both the BAGO host lattice and the Eu^(2+)ions activated BAGO phosphors were investigated through field-emission scanning electron microscopy and X-ray diffractometry analyses,respectively.The BAGO host lattice has micro-sized particles and the Rietveld refinement reveals the presence of a monoclinic crystal phase,characterized by the space group I2/c(No.15).Introducing Eu^(2+)ions into Ba^(2+)sites under CO condition reduces the particle size,switching from microscale to nanoscale.Within the near-ultraviolet spectrum(353 nm),the BAGO:xEu^(2+)phosphors exhibit a broadband bluish-green photoluminescence(PL)emission characterized by a peak band at 492 nm.This phenomenon is attributed to the 4f^(6)5d^(1)→4f^(7) electronic transition.The BAGO:0.02Eu^(2+)phosphor shows the strongest bluish-green PL emission,and a co mprehensive description of the concentration quenching mechanism between Eu^(2+)ions is revealed.Additionally,the thermal stability of the optimized BAGO:0.02Eu^(2+)phosphor was investigated,and its activation energy was estimated.Therefore,the synthesized bluish-green BAGO:0.02Eu^(2+)phosphor holds the promise of being a novel and potential candidate for utilization in white light-emitting diode applications.
基金supported by the Food and Health Bureau,Hong Kong SAR Government(reference no.COVID19F06).
文摘The SARS-CoV-2 Omicron variants are notorious for their transmissibility,but little is known about their subgenomic RNA(sgRNA)expression.This study applied RNA-seq to delineate the quantitative and qualitative profiles of canonical sgRNA of 118 respiratory samples collected from patients infected with Omicron BA.2 and compared with 338 patients infected with non-variant of concern(non-VOC)-D614G.A unique characteristic profile depicted by the relative abundance of 9 canonical sgRNAs was reproduced by both BA.2 and non-VOCD614G regardless of host gender,age and presence of pneumonia.Remarkably,such profile was lost in samples with low viral load,suggesting a potential application of sgRNA pattern to indicate viral activity of individual patient at a specific time point.A characteristic qualitative profile of canonical sgRNAs was also reproduced by both BA.2 and non-VOC-D614G.The presence of a full set of canonical sgRNAs carried a coherent correlation with crude viral load(AUC¼0.91,95%CI 0.88–0.94),and sgRNA ORF7b was identified to be the best surrogate marker allowing feasible routine application in characterizing the infection status of individual patient.Further potentials in using sgRNA as a target for vaccine and antiviral development are worth pursuing.
基金financial support from the Key Program of the National Natural Science Foundation of China(82130093)Wenhong Zhang,Juanjuan Zhang acknowledge financial support from Shanghai Municipal Science and Technology Major Project(HS2021SHZX001)+2 种基金Wenhong Zhang acknowledges financial support from the Key Program of the National Natural Science Foundation of China(82161138018 and 82041010)Shanghai Science and Technology Committee(20dz2260100,20Z11901100)Shanghai Hospital Development Center(SHDC2020 CR5010-002).
文摘The SARS-CoV-2 virus,particularly the Omicron BA.2 variant,led to a significant surge in Shanghai,2022.However,the viral load dynamic in Omicron infections with varying clinical severities remain unclear.This prospective cohort included 48,830 hospitalized coronavirus disease 2019(COVID-19)patients across three hospitals in Shanghai,China,between 23 March and 15 May,2022.Systematic nucleic acid testing was performed using RT-PCR Cycle threshold(Ct)value as a proxy of viral load.We analyzed the kinetic characteristics of viral shedding by clinical severity and identified associated risk factors.The study comprised 31.06%asymptomatic cases,67.66%mild-moderate cases,1.00%severe cases,0.29%critical and fatal cases.Upon admission,57%of patients tested positive,with peak viral load observed at 4 days(median Ct value 27.5),followed by a decrease and an average viral shedding time(VST)of 6.1 days(Interquartile range,4.0–8.8 days).Although viral load exhibited variation by age and clinical severity,peak Ct values occurred at similar times.Unvaccinated status,age exceeding 60,and comorbidities including hypertension,renal issues kidney dialysis and kidney transplantation,neurological disorders,rheumatism,and psychotic conditions were found to correlate with elevated peak viral load and extended VST.Asymptomatic cases demonstrated a 40%likelihood of contagiousness within 6 days of detection,while mild-moderate and severe cases exhibited post-symptom resolution infectious probabilities of 27%and over 50%,respectively.These findings revealed that the initial Ct values serve as a predictive indicator of severe outcomes.Unvaccinated elderly individuals with particular comorbidities are at high-risk for elevated viral load and prolonged VST.
