Ke Xu, MD
Professor of PsychiatryDownloadHi-Res Photo
Cards
Appointments
Psychiatry
Primary
Additional Titles
Director of Stress Epigenetics, Yale Stress Center
Staff Psychiatrist, VA Connecticut Healthcare System
Contact Info
Appointments
Psychiatry
Primary
Additional Titles
Director of Stress Epigenetics, Yale Stress Center
Staff Psychiatrist, VA Connecticut Healthcare System
Contact Info
Appointments
Psychiatry
Primary
Additional Titles
Director of Stress Epigenetics, Yale Stress Center
Staff Psychiatrist, VA Connecticut Healthcare System
Contact Info
About
Titles
Professor of Psychiatry
Director of Stress Epigenetics, Yale Stress Center
Positions outside Yale
Staff Psychiatrist, VA Connecticut Healthcare System
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.
Last Updated on April 07, 2025.
Appointments
Psychiatry
ProfessorPrimaryBiomedical Informatics & Data Science
ProfessorSecondary
Other Departments & Organizations
- Biomedical Informatics & Data Science
- Division of Addictions
- 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
Genetics, Behavioral; Mental Disorders
Public Health Interests
Mental Health; Substance Use, Addiction; Genetics, Genomics, Epigenetics
ORCID
0000-0002-6472-7052
Research at a Glance
Yale Co-Authors
Frequent collaborators of Ke Xu's published research.
Rajita Sinha, PhD
Amy Justice, MD, PhD
Zachary Harvanek, MD, PhD
Christopher T Rentsch, PhD, FISPE
Hang Zhou, PhD
Joel Gelernter, MD
Publications
2025
Two-photon and three-photon excitation in GaN by spectrally broadband and few-cycle laser pulses
Wang M, Xiao J, Wang M, Yi J, Song Y, Zhang Y, Wang J, Cao B, Lienau C, Xu K. Two-photon and three-photon excitation in GaN by spectrally broadband and few-cycle laser pulses. Optics & Laser Technology 2025, 191: 113334. DOI: 10.1016/j.optlastec.2025.113334.Peer-Reviewed Original ResearchConceptsThree-photon excitationTwo-photonGaN near band edge emissionsFew-cycle laser pulsesFew-cycle pulsesSimultaneous two-photonSpatial intensity fluctuationsMultiple nonlinear processesFew-cycleLaser pulsesBroadband pulsesNear-band-edge emissionFrequency conversionIntensity fluctuationsElectronic signal processingUltrashort laserPetahertzNonlinear interactionsNonlinear signalsExcitationGaNNonlinear processesSurface morphologyFilm qualityPulseLuminescence properties of homoepitaxial Mg-doped GaN under different doping concentrations and annealing atmospheres
Wu W, Shu Z, Wang X, Wang Y, Pan Y, Sun J, Gao X, Zheng S, Wang M, Zeng X, Xu K. Luminescence properties of homoepitaxial Mg-doped GaN under different doping concentrations and annealing atmospheres. Journal Of Luminescence 2025, 284: 121294. DOI: 10.1016/j.jlumin.2025.121294.Peer-Reviewed Original ResearchConceptsLuminescence propertiesDoping concentrationP-type GaN thin filmMg-doped GaNGaN thin filmsMg dopingRoom temperature PLAcceptor energy levelCm-3Defect statesEnergy levelsMgGa acceptorN2 annealingO2 annealingCL spectraMg doping concentrationAnnealing atmosphereFS substrateThin filmsLuminescenceDopingGaN.Low temperaturesAnnealingAcceptorMicrostructure and thermal conductance of the AlN-on-sapphire heterostructure prepared by metal-organic chemical vapor deposition
Wang L, Zhou J, Su X, Chen J, Li Z, Zhu J, Zhang Z, Chang G, Xia S, Yin T, Niu M, Tang D, Xu K. Microstructure and thermal conductance of the AlN-on-sapphire heterostructure prepared by metal-organic chemical vapor deposition. Vacuum 2025, 238: 114335. DOI: 10.1016/j.vacuum.2025.114335.Peer-Reviewed Original ResearchConceptsAlN-on-sapphireThickness of AlN filmMetal organic chemical vapor depositionAlN filmsChemical vapor depositionAlN/sapphire interfaceThermal conductivityVapor depositionIncrease of tensile stressTime-domain thermoreflectance techniqueAlN film thicknessAlGaN-based ultraviolet light-emitting diodesAlGaN-based UV LEDsChemically bonded interfaceInterfacial thermal conductanceHeat transfer abilityHeat transfer mechanismPhonon densityUltraviolet light-emitting diodesUV LEDsMicrostructure of AlNAlN thicknessAlN/sapphireLarger lattice mismatchLattice mismatchTa-based Au-free and low annealing temperature ohmic contacts on GaN and AlGaN/GaN heterostructures
Xia S, Zhang Y, Sun Y, Zhu Q, Liu W, Wang J, Xu K. Ta-based Au-free and low annealing temperature ohmic contacts on GaN and AlGaN/GaN heterostructures. Materials Letters 2025, 391: 138473. DOI: 10.1016/j.matlet.2025.138473.Peer-Reviewed Original ResearchMitochondrial DNA Haplogroups, Biomarkers of Inflammation and Immune Activation, and Risk of Diabetes in Veterans With and Without Human Immunodeficiency Virus
Yan A, Kundu S, Samuels D, Bailin S, Xu K, So-Armah K, Butt A, Gerschenson M, Goetz M, Doyle M, Tracy R, Marconi V, Justice A, Freiberg M, Koethe J, Hulgan T. Mitochondrial DNA Haplogroups, Biomarkers of Inflammation and Immune Activation, and Risk of Diabetes in Veterans With and Without Human Immunodeficiency Virus. The Journal Of Infectious Diseases 2025, jiaf304. PMID: 40488298, DOI: 10.1093/infdis/jiaf304.Peer-Reviewed Original ResearchAltmetricConceptsHaplogroup L3MtDNA haplogroupsCD4+ T cellsAssociated with incident DMVeterans Aging Cohort StudyBlack PWHT cellsMitochondrial DNA haplogroupsIncident DMHaplogroupsWomen of African ancestryVeterans Aging Cohort Study participantsHaplogroup associationsT-cell phenotypeHuman immunodeficiency virusType 2 diabetes mellitusSerum IL-6Associated with DMBiomarkers of inflammationCellular immune biomarkersAging Cohort StudyRisk of diabetesDM outcomesGenome-wide genotypingCD28-negativeGrowth behavior and optical properties of V-pits in GaN grown by a Na flux method
Zhang T, Liu Z, Si Z, Peng X, Dong X, Li M, Tang N, Xu K. Growth behavior and optical properties of V-pits in GaN grown by a Na flux method. CrystEngComm 2025, 27: 3675-3681. DOI: 10.1039/d5ce00095e.Peer-Reviewed Original ResearchConceptsHotspot and nonequilibrium thermal transport in AlGaN/GaN FinFET: A coupled electron-phonon Monte Carlo simulation study
Hu B, Wang Z, Xu K, Tang D. Hotspot and nonequilibrium thermal transport in AlGaN/GaN FinFET: A coupled electron-phonon Monte Carlo simulation study. International Journal Of Heat And Mass Transfer 2025, 241: 126679. DOI: 10.1016/j.ijheatmasstransfer.2025.126679.Peer-Reviewed Original ResearchCitationsConceptsNonequilibrium thermal transportThermal transportAlGaN/GaN FinFETsPolar optical scatteringElectron-phonon scatteringThermal transport processesPrimary phonon modesFirst-principles calculationsSevere self-heating effectPhonon modesStrong nonequilibriumEmission processMonte Carlo simulationsEnergy dissipation processIntermediate stateDissipative processesOptical scatteringSelf-heating effectCarlo simulationsTransport processesDissipation timeScatteringPeak temperature riseCoupling effectComplex transport mechanismsResearch on the epitaxial growth of Power/RF HEMT structures on n-GaN and Fe-doped SI-GaN Free-Standing Substrates by MOCVD
Wang X, Zhang Y, Wang M, Wang J, Xu K. Research on the epitaxial growth of Power/RF HEMT structures on n-GaN and Fe-doped SI-GaN Free-Standing Substrates by MOCVD. Vacuum 2025, 235: 114135. DOI: 10.1016/j.vacuum.2025.114135.Peer-Reviewed Original ResearchCitationsConceptsMetal organic chemical vapor depositionHigh-electron-mobility transistorsEpitaxial layersTwo-dimensional electron gasAlGaN/GaN high-electron-mobility transistorsEpitaxial growthLow-temperature mobilityGaN channel layerSemi-insulating GaNFree-standing GaN substratesGaN buffer layerRadio frequencyFe impurity concentrationsElectron gasChemical vapor depositionImpurity concentrationHEMT structuresEpitaxial structureDislocation densityN-GaNLow-temperature growthGaN substratesStopper layerChannel layerSurface roughnessUltralow Contact Resistivity of <0.13 Ω · mm for Normal Ti/Al/Ni/Au Ohmic Contact on Non-Recessed i-AlGaN/GaN
Wang X, Lin Z, Zhang Y, Wang J, Xu K. Ultralow Contact Resistivity of <0.13 Ω · mm for Normal Ti/Al/Ni/Au Ohmic Contact on Non-Recessed i-AlGaN/GaN. IEEE Transactions On Electron Devices 2025, 72: 2246-2251. DOI: 10.1109/ted.2025.3555265.Peer-Reviewed Original ResearchA Review of the Evolution of Residual Stresses in Additive Manufacturing During Selective Laser Melting Technology
Bian P, Jammal A, Xu K, Ye F, Zhao N, Song Y. A Review of the Evolution of Residual Stresses in Additive Manufacturing During Selective Laser Melting Technology. Materials 2025, 18: 1707. PMID: 40333274, PMCID: PMC12028742, DOI: 10.3390/ma18081707.Peer-Reviewed Original ResearchConceptsResidual stressAdditive manufacturingEvolution of residual stressesSelective laser melting technologyAreas of compressive stressLaser melting technologyApplication of SLMPlane stressLaser meltingTensile stressCompressive stressMelting technologyParameter matchingThermal stressPlane directionComponent failuresDominant stressFormation mechanismTemperature gradientSurface layerSLMRoom temperatureDistribution regularityRegularities of distributionExcessive stress
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
Honors
honor Lustman Resident Research Award: the first place
06/10/2011Yale School of Medicine AwardDetailsUnited Stateshonor APA/Merck &Co Early Academic Career Research Award
05/12/2011National AwardDetailsUnited 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
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