Ke Xu, MD
Professor of PsychiatryCards
About
Research
Overview
Medical Research Interests
Genetics, Behavioral; Mental Disorders
Public Health Interests
Genetics, Genomics, Epigenetics; Mental Health; Substance Use, Addiction
Publications
2025
Effect of AlN interlayer thickness on thermal conductances of GaN epilayer and GaN/SiC interface in GaN-on-SiC heterostructures
Wang L, Zhang Z, Su X, Zhou J, Chen J, Li Z, Chang G, Xia S, Yin T, Niu M, Zhu J, Tang D, Xu K. Effect of AlN interlayer thickness on thermal conductances of GaN epilayer and GaN/SiC interface in GaN-on-SiC heterostructures. Applied Surface Science 2025, 686: 162106. DOI: 10.1016/j.apsusc.2024.162106.Peer-Reviewed Original ResearchHigh electron mobility transistorsAlN interlayer thicknessGaN-on-SiCGaN epilayersAlN interlayerPhonon density of statesHeteroepitaxial growth of GaNDensity of statesAtomically smooth interfaceThermal conductivityElectron mobility transistorsTime-domain thermoreflectanceMultilayer structureEnhancement of G′Growth of GaNInterfacial thermal conductanceInterlayer thicknessMetal organic chemical vapor depositionSiC substrateMobility transistorsAlN bufferGrow GaNChemical vapor depositionIsland shapeGaN
2024
Epigenome-Wide and Methylation Risk Score Analysis of Body Mass Index Among People with HIV
Abi N, Young A, Tiwari P, Chen J, Liu C, Hui Q, So-Armah K, Freiberg M, Justice A, Xu K, Gwinn M, Marconi V, Sun Y. Epigenome-Wide and Methylation Risk Score Analysis of Body Mass Index Among People with HIV. Epigenomes 2024, 8: 46. DOI: 10.3390/epigenomes8040046.Peer-Reviewed Original ResearchMethylation risk scoreBody mass indexReduce cardiometabolic disease riskBody mass index associationsMass indexBody mass index varianceRisk of type 2 diabetesVeterans Aging Cohort StudyEpigenome-wide association studiesAnalysis of body mass indexCardiometabolic disease riskAntiretroviral therapyAging Cohort StudyNon-HIV individualsObesity-related risksEpigenome-wide significant CpG-sitesMale PWHLinear mixed modelsTargeted interventionsType 2 diabetesCohort studyDisease riskRisk scorePWHAssociation studiesNanoindentation mechanical studies of bulk AlN single crystals with different orientations
Zhou H, Chen K, Gao X, Zheng S, Zeng X, Wang C, Wang Y, Pan Y, Xu K. Nanoindentation mechanical studies of bulk AlN single crystals with different orientations. Semiconductor Science And Technology 2024, 40: 015008. DOI: 10.1088/1361-6641/ad98b8.Peer-Reviewed Original ResearchIndentation depthYoung's modulusPhysical vapor transportIncreasing indentation depthIndentation size effectNano-mechanical testingLuminescence quenchingSmall Young's modulusCrystal planesSingle crystalsCrystal substratesRaman spectroscopyMechanical propertiesPanchromatic CL imagesLocal stressAlN single crystalsSurface morphologyMechanism studyAluminum nitrideProperties of AlNSlip regionCrystalIndentationStructural defectsModulusNucleation study of AlN crystal growth on 6H-SiC substrates using the MOCVD
Lu Z, Wang Y, Wang L, Xu Y, Liu Y, Xu K. Nucleation study of AlN crystal growth on 6H-SiC substrates using the MOCVD. Applied Physics Letters 2024, 125: 242101. DOI: 10.1063/5.0238459.Peer-Reviewed Original ResearchFormation energyNucleation morphologyAlN crystal growthCrystal growthMolecular dynamics simulationsMetal organic chemical vapor deposition technologyFilm growth processIsland growth modeAlN thin filmsChemical vapor deposition technologyN atomsThin film growth processAdsorption capacityVapor deposition technologyStronger adsorption capacityAtomic structureAdsorption energyAl atomsDynamics simulationsThin filmsGrowth modeHexagonal AlNDeposition technologyAlNStacking faultsImproved surface morphology and reduced V-pits density of lattice-matched AlInN films grown by atmospheric pressure metalorganic chemical vapor deposition
Fan S, Ikeda M, Zhang B, Li Z, Su X, Liu Z, Xu K. Improved surface morphology and reduced V-pits density of lattice-matched AlInN films grown by atmospheric pressure metalorganic chemical vapor deposition. Journal Of Alloys And Compounds 2024, 1007: 176406. DOI: 10.1016/j.jallcom.2024.176406.Peer-Reviewed Original ResearchMetalorganic chemical vapor depositionChemical vapor depositionSurface morphologyVapor depositionPressure metalorganic chemical vapor depositionSevere parasitic reactionsAtmospheric pressure metalorganic chemical vapor depositionAtmospheric-pressure metalorganic chemical vapor depositionIn-plane uniformityLow surface roughnessV-pit densityExcellent surface morphologyAtomic force microscopyGaN/AlInN interfacesParasitic reactionsSurface roughnessGrowth temperatureSecond-order reaction modelReduced roughnessFilm thicknessAlInN filmsForce microscopyRoughness valuesCrystalline qualityElectronic devicesOptical characterization of GaN:Eu microcrystals grown by the ammonothermal method
Xie K, Li T, Ren G, Wang L, Lu W, Shen L, Zhou H, Xu K. Optical characterization of GaN:Eu microcrystals grown by the ammonothermal method. Journal Of Alloys And Compounds 2024, 1008: 176776. DOI: 10.1016/j.jallcom.2024.176776.Peer-Reviewed Original ResearchGlow discharge mass spectrometryTime-resolved photoluminescenceLuminescent sitesPhotoluminescence excitationScanning electron microscopyEu3+ ionsExposed crystal facesEnergy transfer processAmmonothermal methodCharacteristic luminescenceLuminescence propertiesWurtzite crystal structureO2- ionsCrystal structureExcitation wavelengthMass spectrometryCrystal facesLuminescenceEu concentrationMicrocrystalsLuminescence peakPhotoluminescenceTransfer processOptical characterizationEu0Demonstration of InGaN Micro-Light-Emitting Diodes with Long Wavelength Emission Based on GaN Substrate
Xu W, Wang G, Huang J, Wang Q, Zhang L, Li K, Xu K. Demonstration of InGaN Micro-Light-Emitting Diodes with Long Wavelength Emission Based on GaN Substrate. 2024, 00: 41-44. DOI: 10.1109/sslchinaifws64644.2024.10835382.Peer-Reviewed Original ResearchA multi-trait epigenome-wide association study identified DNA methylation signature of inflammation among men with HIV
Chen J, Hui Q, Titanji B, So-Armah K, Freiberg M, Justice A, Xu K, Zhu X, Gwinn M, Marconi V, Sun Y. A multi-trait epigenome-wide association study identified DNA methylation signature of inflammation among men with HIV. Clinical Epigenetics 2024, 16: 152. PMID: 39488703, PMCID: PMC11531128, DOI: 10.1186/s13148-024-01763-2.Peer-Reviewed Original ResearchConceptsEpigenome-wide association studiesDNA methylationAssociation studiesDNAm sitesDNA methylation sitesAssociated with DNA methylationDNA methylation signaturesInflammatory markersResponse to virusesImmune response to virusesVeterans Aging Cohort StudySignatures of inflammationGenesIdentified sitesAging Cohort StudyInflammation-related genesPathwayPersistent inflammationMale PWHCohort studyExcess morbidityPWHStudy populationInflammationStatistical powerHBI: a hierarchical Bayesian interaction model to estimate cell-type-specific methylation quantitative trait loci incorporating priors from cell-sorted bisulfite sequencing data
Cheng Y, Cai B, Li H, Zhang X, D’Souza G, Shrestha S, Edmonds A, Meyers J, Fischl M, Kassaye S, Anastos K, Cohen M, Aouizerat B, Xu K, Zhao H. HBI: a hierarchical Bayesian interaction model to estimate cell-type-specific methylation quantitative trait loci incorporating priors from cell-sorted bisulfite sequencing data. Genome Biology 2024, 25: 273. PMID: 39407252, PMCID: PMC11476968, DOI: 10.1186/s13059-024-03411-7.Peer-Reviewed Original ResearchConceptsMethylation quantitative trait lociQuantitative trait lociTrait lociMethylation dataFunctional annotation of genetic variantsAnnotation of genetic variantsGenetic variantsBisulfite sequencing dataEffects of genetic variantsBiologically relevant cell typesDNA methylation levelsCell typesFunctional annotationSequence dataComplex traitsMethylation datasetsRelevant cell typesMeQTLsMethylation levelsMethylation regulatorsReal data analysesLociVariantsMethylationDNAHigh-power AlGaN deep-ultraviolet micro-light-emitting diode displays for maskless photolithography
Feng F, Liu Y, Zhang K, Yang H, Hyun B, Xu K, Kwok H, Liu Z. High-power AlGaN deep-ultraviolet micro-light-emitting diode displays for maskless photolithography. Nature Photonics 2024, 1-8. DOI: 10.1038/s41566-024-01551-7.Peer-Reviewed Original ResearchMicro-light-emitting diodesMicro-LED displayMicro-LEDsMaskless photolithographySuperior light extraction efficiencyPeak external quantum efficiencyLight extraction efficiencyMicro-LED arrayExternal quantum efficiencyElectrical characterizationCircuit driverDeep ultravioletPhotoresist filmSpreading uniformityQuantum efficiencyEmission uniformityPhotolithographySemiconductor industryHeat dispersionMicro-displaysMaximum brightnessReflective layerPhotolithography applicationsOptimal performanceDiodes
Clinical Trials
Current Trials
A longitudinal study of the effects of cannabis exposure on neuro-development in adolescents and young adults
HIC ID2000024543RoleSub InvestigatorPrimary Completion Date01/31/2021Recruiting ParticipantsGenderBothAge13 years - 25 years
Academic Achievements & Community Involvement
News
News
- May 20, 2024Source: Journal of Behavioral Medicine
Childhood Adversity, Accelerated GrimAge, and Associated Health Consequences
- December 07, 2023
VA/Yale Researchers Lead Multi-ancestry Study of Genetics of Problematic Alcohol Use
- July 24, 2023Source: Neurobiology of Stress
Greater Stress and Trauma Mediate Race-Related Differences in Epigenetic Age Between Black and White Young Adults in a Community Sample
- March 15, 2022
Alcohol Consumption Changes the Aging Clock
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