Ke Xu, MD
Professor of PsychiatryCards
Appointments
Additional Titles
Director of Stress Epigenetics, Yale Stress Center
Contact Info
Appointments
Additional Titles
Director of Stress Epigenetics, Yale Stress Center
Contact Info
Appointments
Additional Titles
Director of Stress Epigenetics, Yale Stress Center
Contact Info
About
Titles
Professor of Psychiatry
Director of Stress Epigenetics, Yale Stress Center
Biography
Dr. Xu is a Professor of Psychiatry at Yale School of Medicine and holds a position as Staff Psychiatrist at the VA Connecticut Healthcare System. Her research is dedicated to exploring the complex interactions between stress and the epigenome, aiming to uncover how these interactions contribute to the development of stress-related symptoms and disorders such as substance use. This important work has led Dr. Xu to investigate a broad spectrum of behavioral and medical conditions in diverse populations. Dr. Xu is engaged in the field of social epigenomics that helps us understanding the biological underpinnings of the effects of social environments on health.
Appointments
Psychiatry
ProfessorPrimaryBiomedical Informatics & Data Science
ProfessorSecondary
Other Departments & Organizations
- Biomedical Informatics & Data Science
- Division of Addictions
- Division of Mental Health Services
- Neuroscience Research Training Program (NRTP)
- Psychiatry
- Xu Lab
- Yale Center for the Science of Cannabis and Cannabinoids
- Yale Stress Center
- Yale Ventures
- Yale-UPR Integrated HIV Basic and Clinical Sciences Initiative
Education & Training
- Resident
- Yale School of Medicine (2011)
- MD
- West China College of Medicine, Sichuan University (2007)
Research
Overview
Medical Research Interests
Public Health Interests
ORCID
0000-0003-2628-2061
Research at a Glance
Yale Co-Authors
Rajita Sinha, PhD
Amy Justice, MD, PhD
Zachary Harvanek, MD/PhD
Christopher T Rentsch, PhD, FISPE
Hang Zhou, PhD
Joel Gelernter, MD
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 ResearchConceptsHigh 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 ResearchConceptsMethylation 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 ResearchConceptsIndentation 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 ResearchConceptsFormation 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 ResearchConceptsMetalorganic 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 ResearchConceptsGlow 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 characterizationEu0A 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 ResearchAltmetricMeSH Keywords and ConceptsConceptsEpigenome-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 powerHigh-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 ResearchAltmetricConceptsMicro-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 performanceDiodesHBI: 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 ResearchAltmetricMeSH Keywords and ConceptsConceptsMethylation 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 analysesLociVariantsMethylationDNAFrequent Cocaine Use is Associated With Larger HIV Latent Reservoir Size
Aouizerat B, Garcia J, Domingues C, Xu K, Quach B, Page G, Konkle-Parker D, Bolivar H, Lahiri C, Golub E, Cohen M, Kassaye S, DeHovitz J, Kuniholm M, Archin N, Tien P, Hancock D, Johnson E. Frequent Cocaine Use is Associated With Larger HIV Latent Reservoir Size. JAIDS Journal Of Acquired Immune Deficiency Syndromes 2024, 97: 156-164. PMID: 39250649, DOI: 10.1097/qai.0000000000003472.Peer-Reviewed Original ResearchCitationsConceptsHIV latent reservoirImpact of cocaine useCocaine useT cellsAssociated with higher HIV viral loadHigher HIV viral loadSelf-reported cocaine useHIV DNA assaysLatent reservoir sizeRapid HIV progressionVirologically suppressed womenHIV viral loadFrequent cocaine useVirally suppressed PLWHHistory of HIVLatent reservoirAntiretroviral therapyHIV progressionLongitudinal cohort studyViral loadCocaine usersNever usersIntact provirusesCohort studyCD4
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
honor Lustman Resident Research Award: the first place
Yale School of Medicine AwardDetails06/10/2011United Stateshonor APA/Merck &Co Early Academic Career Research Award
National AwardDetails05/12/2011United States
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