简介：Objective:Toinvestigatethebindingcharacteristicsofendothelialcell(EC)withLPSfreefromtheparticipationofserumfactors.Methods:LaserconfocalmicroscopewasemployedintheobservationofthebindingofECwithFITC-LPS.TheKDandthebindingsitesofeachECwerecalculatedbyradioligandbindingassayofreceptors(RBA)using[3H]-LPS.Results:ThebindingofECwithLPSwassaturable,timeandconcentrationdependentanditcouldbecompetedwithoverdosedLPSofthesametype.Thefluorescencemainlydistributedincytoplasm,especiallynearthenucleus,whichcouldalsobestained.Conclusions:TheremightbesomespecificLPSbindingsitesexistingonEcsandLPScouldfunctionintracellularily.

简介：AbstractThe virulence of influenza viruses is a complex multigenic trait. Previous studies about the virulence determinants of influenza viruses mainly focused on amino acid sites, ignoring the influence of nucleotide mutations. In this study, we collected >200 viral strains from 21 subtypes of influenza A viruses with virulence in mammals and obtained over 100 mammalian virulence-related nucleotide sites across the genome by computational analysis. Fifty of these nucleotide sites only experienced synonymous mutations. Experiments showed that synonymous mutations in three high-scoring nucleotide sites, i.e., PB1–2031, PB1–633, and PB1–720, enhanced the pathogenicity of the influenza A(H1N1) viruses in mice. Besides, machine-learning models with accepted accuracy for predicting mammalian virulence of influenza A viruses were built. Overall, this study highlighted the importance of nucleotide mutations, especially synonymous mutations in viral virulence, and provided rapid methods for evaluating the virulence of influenza A viruses. It could be helpful for early warning of newly emerging influenza A viruses.

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简介：Objective:Toinvestigatetheinfluenceofdifferentrightventricular(RV)pacingsitesonQRSwidth,andtoprovideapotentialreferencesiteforpermanentrightventricularpacinginpatientsimplantedwithpermanentpacemakers.PacingatthesitewiththeshortestQRSdurationmayreducethedeleteriouseffectsofRVpacingonLVfunction,andthushavingbeneficialeffectsonpatient’soutcome.Methods:AllconsecutivepatientswhowereplannedtohavepermanentpacemakerimplantationforaClassIorIIaindicationatourdepartmentfromOctober2010toJuly2012werescreenedfortheparticipationinthisprospective,singlecenter,non-randomizedstudy.ThebaselinesurfaceECGwasanalyzedforQRSwidthandmorphology,respectively.DuringtheimplantationprocedurepatientsweretransientlypacedatdifferentRVlocations(rightventricularapex,rightventricularinflowtract[RVIT],midseptum,highseptumandrightventricularoutflowtract[RVOT])beforetheleadwasplacedatitsfinalposition.Duringpacingatthedifferentpositionsthesurface12-leadsECGwasrecorded.BasedonthesurfaceofECGQRSdurationandmorphologyofthedifferentrightventricularpacingsiteswereanalyzedandcomparedwithbaselineandtoeachother.Results:Atotalof216patients(39%female,meanage69±13years,higherdegreeAVblock30.5%)wasenrolledinthestudy.PacedQRSdurationwassignificantlydifferentbetweenallrightventricularpacingsitescomparedwiththebaselineECG(baseline:106ms±21ms;meanpaced:158ms±16ms;p<0.001).RVApacingshowedthewidestQRS(168ms±16ms).QRSdurationwithRVITpacingwas166ms±15ms,andthatwithRVOTpacingwas165ms±15ms,respectively.QRSdurationwasnotsignificantlydifferentbetweenthesethreepositions.Mid-septalpacingshowedthenarrowestQRS(139ms±19ms)comparedtoallotherpacingsites(p<0.001).Pacingatthehigh-septumshowedabroaderQRS(153ms±14ms)thanthatpacingatthemid-septum.Comparedtootherrightventricularpacingsites

简介：AbstractObjective:The coronavirus disease 2019 (COVID-19) epidemic resulting from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has still spread globally. The occurrence of the Delta variant, which is more infectious and spreads faster than earlier forms of the virus that causes COVID-19, makes infection prevention more challenging. Therefore, this study aimed to gain a comprehensive insight into the transmission routes of SARS-CoV-2 for curbing the propagation of SARS-CoV-2 in human populations.Methods:We studied a prospective cohort of 576 patients admitted consecutively to the First Affiliated Hospital of Guangzhou Medical University from January 21 to June 8, 2020. These patients were chosen based on their similar clinical phenotypes or imaging findings. There were 21 (3.6%) laboratory-confirmed COVID-19 patients (16 severe and 5 mild cases) and 555 non-COVID-19 patients. The antibody response and routes and duration of viral shedding were systematically evaluated in serial clinical specimens. Moreover, SARS-CoV-2 RNA was also detected in a mouth rinse, urine, and tear samples. This study was approved by the Medical Ethical Committee of The First Affiliated Hospital of Guangzhou Medical University (approval No. 2020-77).Results:SARS-CoV-2 mainly existed in sputum, nasal and throat swabs, and feces samples. Virus latency was longer in sputum and feces samples than in nasopharyngeal samples. IgG antibody response in respiratory samples was related to disease severity. Although droplets and aerosols are the major transmission routes for COVID-19, covert routes of transmission from asymptomatic patients, contaminated surfaces, and wastewater are also of interest.Conclusion:Our findings provide a solid foundation for developing prophylactic measures against SARS-CoV-2.