0000000000568634

AUTHOR

R. Oliva

showing 6 related works from this author

High-pressure optical absorption in InN: Electron density dependence in the wurtzite phase and reevaluation of the indirect band gap of rocksalt InN

2012

We report on high-pressure optical absorption measurements on InN epilayers with a range of free-electron concentrations (5×1017–1.6×1019 cm−3) to investigate the effect of free carriers on the pressure coefficient of the optical band gap of wurtzite InN. With increasing carrier concentration, we observe a decrease of the absolute value of the optical band gap pressure coefficient of wurtzite InN. An analysis of our data based on the k·p model allows us to obtain a pressure coefficient of 32 meV/GPa for the fundamental band gap of intrinsic wurtzite InN. Optical absorption measurements on a 5.7-μm-thick InN epilayer at pressures above the wurtzite-to-rocksalt transition have allowed us to o…

Electron densityPhase transitionMaterials scienceCondensed matter physicsBand gapCondensed Matter PhysicsPressure coefficientIII-V NitridesElectronic Optical and Magnetic MaterialsFISICA APLICADAAlloysDirect and indirect band gapsAbsorption (logic)StabilityEnergy (signal processing)Wurtzite crystal structurePhysical Review B
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Pressure dependence of the refractive index in wurtzite and rocksalt indium nitride

2014

We have performed high-pressure Fourier transform infrared reflectance measurements on a freestanding InN thin film to determine the refractive index of wurtzite InN and its high-pressure rocksalt phase as a function of hydrostatic pressure. From a fit to the experimental refractive-index curves including the effect of the high-energy optical gaps, phonons, free carriers, and the direct (fundamental) band-gap in the case of wurtzite InN, we obtain pressure coefficients for the lowfrequency (electronic) dielectric constant e1 . Negative pressure coefficients of -8.8 × 10-2 GPa-1 and -14.8 × 10-2 GPa-1 are obtained for the wurtzite and rocksalt phases, respectively. The results are discussed …

Materials scienceIndium nitridePhysics and Astronomy (miscellaneous)Condensed matter physicsBand gapHydrostatic pressureRefractive indexDielectricHigh pressureCondensed Matter::Materials Sciencechemistry.chemical_compoundchemistryBand gapPhononsCritical point phenomenaThin filmElectronic band structureRefractive indexWurtzite crystal structureApplied Physics Letters
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High-pressure lattice dynamics in wurtzite and rocksalt indium nitride investigated by means of Raman spectroscopy

2013

We present an experimental and theoretical lattice-dynamical study of InN at high hydrostatic pressures. We perform Raman scattering measurements on five InN epilayers, with different residual strain and free electron concentrations. The experimental results are analyzed in terms of ab initio lattice-dynamical calculations on both wurtzite InN (w-InN) and rocksalt InN (rs-InN) as a function of pressure. Experimental and theoretical pressure coefficients of the optical modes in w-InN are compared, and the role of residual strain on the measured pressure coefficients is analyzed. In the case of the LO band, we analyze and discuss its pressure behavior considering the double-resonance mechanis…

Free electron modelMaterials scienceIndium nitridePhononAb initioMolecular physicsChargeScatteringN-type inpMathematics::Group TheoryCondensed Matter::Materials Sciencesymbols.namesakechemistry.chemical_compoundEffective mass (solid-state physics)DependencePseudopotentialsWurtzite crystal structureCondensed matter physicsCondensed Matter PhysicsIII-V NitridesGanElectronic Optical and Magnetic MaterialschemistryFISICA APLICADAsymbolsModesConstantsRaman spectroscopyStabilityRaman scatteringPhysical Review B
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SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

2021

Abstract Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18–49, 50–69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results NNVs were more favourable in su…

MaleCOVID-19 Vaccinesafe surgery; vaccination modelling; COVID-19Vascular damage Radboud Institute for Health Sciences [Radboudumc 16]MULTICENTERComorbidity030230 surgery0302 clinical medicinephase 3 clinical trial (topic)Case fatality rateProspective StudiesSARS-CoV-2 Vaccination Safe surgeryCOVID-19/epidemiologySARS-CoV-2 ; vaccination ; safe surgeryeducation.field_of_studycase fatality rateVaccinationVaccinationAdolescent; Adult; Aged; COVID-19; COVID-19 Vaccines; Comorbidity; Elective Surgical Procedures; Female; Humans; Male; Middle Aged; Postoperative Complications; Preoperative Period; Prospective Studies; SARS-CoV-2; Vaccination; Young Adulthealth care policyElective Surgical Procedures030220 oncology & carcinogenesisvaccination modellingPreoperative PeriodCOVID-19; SARS-CoV-2; cancer; vaccination; outcome; mortality; infection; modellingCohort studyprospective studyHumanmedicine.medical_specialtyArticle03 medical and health sciencesSARS-CoV-2 vaccinationSDG 3 - Good Health and Well-beingCOVID-19 Vaccines/pharmacologyHumansVaccination/methodsElective surgeryeducationAgedScience & TechnologyElective Surgical Procedureadult; aged; Article; cancer grading; cancer surgery; case fatality rate; computer assisted tomography; elective surgery; female; follow up; health care policy; human; incidence; infection rate; infection risk; major clinical study; male; middle aged; mortality; outcome assessment; phase 3 clinical trial (topic); preoperative care; prospective study; sensitivity analysis; seroprevalence; Severe acute respiratory syndrome coronavirus 2; vaccination; young adult; COVID-19; COVID-19 Vaccines; Comorbidity; Elective Surgical Procedures; Postoperative Complications; Preoperative Period; SARS-CoV-2; Vaccination; surgery.Cura preoperatòriamajor clinical studymortalityinfectionProspective StudieincidenceSurgeryHuman medicinePostoperative Complication610 Medizin und GesundheitAcademicSubjects/MED00910Settore MED/18 - CHIRURGIA GENERALESettore MED/29 - CHIRURGIA MAXILLOFACCIALEcomputer assisted tomographyESTUDOS PROSPECTIVOSsurgerysafe surgeryPostoperative Complicationssensitivity analysisSevere acute respiratory syndrome coronavirus 2preoperative careVacunacióProspective cohort studyseroprevalenceIncidence (epidemiology)covidElective Surgical Procedures/methodsMiddle Agedcancer gradingCOVID vaccinationoutcome/dk/atira/pure/sustainabledevelopmentgoals/good_health_and_well_beingSARS-CoV-2; vaccination; surgeryOriginal ArticleFemalecancer surgeryAcademicSubjects/MED00010Life Sciences & BiomedicineAdultCOVID-19 VaccinesAdolescentinternational prospective cohort studyPostoperative Complications/prevention & controlPopulationinfection rateSARS-CoV-2/immunologyNOmodellingYoung Adultmedicinefollow upcancerddc:610infection riskoutcome assessmentLS7_4business.industrySARS-CoV-2Number needed to vaccinatePreoperative careCOVID-193126 Surgery anesthesiology intensive care radiologySettore MED/18Reconstructive and regenerative medicine Radboud Institute for Health Sciences [Radboudumc 10]elective surgeryEmergency medicinebusiness[SDV.MHEP]Life Sciences [q-bio]/Human health and pathologyThe British Journal of Surgery
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Early outcomes and complications following cardiac surgery in patients testing positive for coronavirus disease 2019: An international cohort study

2021

The outbreak of severe acute respiratory syndromecoronavirus-2, the cause of coronavirus disease 2019 (COVID-19) in December 2019 represented a global emergency accounting for more than 2.5 million deaths worldwide.1 It has had an unprecedented influence on cardiac surgery internationally, resulting in cautious delivery of surgery and restructuring of services.2 Understanding the influence of COVID-19 on patients after cardiac surgery is based on assumptions from other surgical specialties and single-center studies. The COVIDSurg Collaborative conducted a multicenter cohort study, including 1128 patients, across 235 hospitals, from 24 countries demonstrating perioperative COVID-19 infection…

Pulmonary and Respiratory MedicineMale2019-20 coronavirus outbreakmedicine.medical_specialtyCoronavirus disease 2019 (COVID-19)Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)complication.ArticleNOCohort Studiesoutcomes; complications; following cardiac surgery; coronavirus disease 2019Postoperative ComplicationsCardiovascular Diseases; Cohort Studies; Female; Humans; Male; Middle Aged; SARS-CoV-2; COVID-19; Cardiac Surgical Procedures; Postoperative ComplicationsInternal medicineCardiovascular DiseasemedicineCardiac Surgical ProcedureHumansIn patientCardiac Surgical ProceduresLS7_4business.industrySARS-CoV-2COVID-19Middle AgedCardiac surgeryCardiovascular DiseasesoutcomeSurgeryFemaleCohort StudieCardiology and Cardiovascular Medicinebusinesscardiac surgery[SDV.MHEP]Life Sciences [q-bio]/Human health and pathologyCohort studyHuman
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Machine learning risk prediction of mortality for patients undergoing surgery with perioperative SARS-CoV-2: the COVIDSurg mortality score

2021

The British journal of surgery 108(11), 1274-1292 (2021). doi:10.1093/bjs/znab183

Cuidado perioperatorioAcademicSubjects/MED00910Settore MED/18 - CHIRURGIA GENERALEMedizinpulmonary complicationspreoperative screeningDatasets as TopicSurgical Procedures Operative/mortality030230 surgeryperioperative care ; surgical procedures ; operative mortality ; machine learning ; sars-cov-2Medical and Health SciencesProcediments quirúrgicsCohort StudiesMachine LearningTumours of the digestive tract Radboud Institute for Health Sciences [Radboudumc 14]0302 clinical medicineModelsProcedimientos quirúrgicosMedicine and Health SciencesCOVIDSurg Collaborative Co-authorsMedicine030212 general & internal medicineskin and connective tissue diseasesRapid Research Communication11 Medical and Health SciencesOperative/mortalitySARS-CoV-19COVID-19/mortalityStatisticalCOVID-19/mortality; Cohort Studies; Datasets as Topic; Humans; Machine Learning; Models Statistical; Risk Assessment; SARS-CoV-2; Surgical Procedures Operative/mortalityCOVID-19; Cohort Studies; Datasets as Topic; Humans; Machine Learning; SARS-CoV-2; Surgical Procedures Operative; Models Statistical; Risk AssessmentAprendizaje automáticoOperativeSurgical Procedures OperativeoutcomeOperativo[SDV.IB]Life Sciences [q-bio]/BioengineeringPatient SafetyAcademicSubjects/MED000106.4 SurgeryLife Sciences & BiomedicineHuman61medicine.medical_specialty616.9Coronavirus disease 2019 (COVID-19)Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-.Risk AssessmentNOCOVIDSurg CollaborativeVaccine Related03 medical and health sciencesClinical ResearchBiodefenseCures perioperatòriesAprenentatge automàticMortalitatHumansOperatiusLS7_4Surgical ProceduresScience & TechnologyModels Statisticalbusiness.industrySARS-CoV-2SARS-CoV-2 infectionKirurgiPreventionnot indicatedcovid 19fungiEvaluation of treatments and therapeutic interventionsCOVID-19Perioperativecovid 19; pulmonary complications; postoperative mortality risk; SARS-CoV-2 infection; preoperative screening; vaccinationvaccinationmortalityGood Health and Well BeingMortalidadEmergency medicineSurgeryHuman medicineCohort Studiebusinesspostoperative mortality riskPerioperative care
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