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Constraining the Temperature-density Relation of the Inter-galactic Medium from Analytically Modeling LyαForest Absorbers

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Research in Astronomy and Astrophysics 2023年第4期23卷 72-84页

作者： Li Yang Zheng Zheng T.-s.kim shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China school of Astronomy and space sciences University of Chinese Academy of SciencesBeijing 100049China Department of Physics and Astronomy University of Utah115 S 1400 ESalt Lake CityUT 84112USA Department of Astronomy University of Wisconsin475 North Charter StreetMadisonWI 53706USA

The absorption by neutral hydrogen in the intergalactic medium(IGM)produces the Lya forest in the spectra of *** Lya forest absorbers have a broad distribution of neutral hydrogen column density N_(HⅠ) and Doppler b *** narrowest Lya absorption lines(of lowest b)with neutral hydrogen column density above~10^(13)cm^(-2) are dominated by thermal broadening,which can be used to constrain the thermal state of the *** we constrain the temperature-density relation T=T0(ρ/■)γ^(-1) of the IGM at 1.6sing N_(HⅠ) and b parameters measured from 24 high-resolution and high-signal-to-noise quasar spectra and by employing an analytic model to model the N_(HⅠ) -dependent low-b cutoff in the b *** each N_(HⅠ) bin,the b cutoff is estimated using two methods,one non-parametric method from computing the cumulative b distribution and a parametric method from fitting the full b *** find that the IGM temperature T0 at the mean gas densityρshows a peak of~1.5×10^(4) K at z~*** redshift higher than this,the indexγapproximately remains constant,and it starts to increase toward lower *** evolution in both parameters is in good agreement with constraints from completely different approaches,which signals that HeⅡreionization completes around z~3.

关键词： (galaxies:)intergalactic medium-(galaxies:)quasars absorption lines-radiation mechanisms thermal

The butterfly effect in viral infection:From a host DNA single nucleotide change to HBV episome steadiness

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Genes & Diseases 2019年第1期6卷 3-5页

作者： Elena s.kim Haitao Guo Department of Microbiology and Immunology Indiana University School of MedicineIndianapolisINUSA

Chronic hepatitis B virus(HBV)infection is one of the major health care burdens throughout the *** chronicity of HBV infection is supported by the intracellular persistence of a multicopy viral episome called covalently closed circular DNA(cccDNA),which is the bona fide viral transcription template and resistant to currently available antivirals.1 Therefore,noncytolytic elimination of cccDNA is considered as the“holy grail”for a cure of hepatitis B,and the metabolism and transcription regulation of cccDNA have become a hot topic in basic,translational,and clinical HBV research.

关键词： infection metabolism cccDNA

Amorphous silica fiber matrix biomaterials:An analysis of material synthesis and characterization for tissue engineering

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Bioactive Materials 2023年第1期19卷 155-166页

作者： Hyun s.kim sangamesh G.Kumbar syam P.Nukavarapu Department of Biomedical Engineering University of ConnecticutStorrsCTUSA Department of Material science and Engineering University of ConnecticutStorrsCTUSA Department of Orthopaedic surgery University of Connecticut HealthFarmingtonCTUSA

silica biomaterials including Bioglass offer great biocompatibility and bioactivity but fail to provide pore and degradation features needed for tissue *** we report on the synthesis and characterization of novel amorphous silica fiber matrices to overcome these *** silica fibers were fused by sintering to produce porous *** effects of sacrificial polymer additives such as polyvinyl alcohol(PVA)and cellulose fibers(CF)on the sintering process were also *** resulting matrices formed between sintering temperatures of 1,350-1,550◦C retained their fiber *** matrices presented pores in the range of 50-200μm while higher sintering temperatures resulted in increased pore *** addition to silica significantly reduced the pore diameter and porosity compared with silica matrices with or without the addition of *** PVA additive morphologically appeared to fuse the silica fibers to a greater extent and resulted in significantly higher compressive modulus and strength than the rest of the matrices *** matrices lost roughly 30%of their original mass in an in vitro degradation study over 40 *** matrices absorbed 500 wt%of water and did not change in their overall morphology,size,or shape with *** fiber matrices supported human mesenchymal stem cell adhesion,proliferation,and mineralized matrix *** silica fiber biomaterials/matrices reported here are biodegradable and porous and closely resemble the native extracellular matrix structure and water absorption *** the methodology reported here to alter matrix properties may lead to a variety of tissue engineering,implant,and drug delivery applications.

关键词： silica biomaterial Porous matrix ECM-Like fibrous structure Biodegradable Water absorption

Coarse and fine-tuning of lasing transverse electromagnetic modes in coupled all-inorganic perovskite quantum dots

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Nano Research 2021年第1期14卷 108-113页

作者： Youngsin Park Guanhua Ying Atanu Jana Vitaly Osokin Claudius C.Kocher Tristan Farrow Robert A.Taylor Kwang s.kim school of Natural science Ulsan National Institute of Science and TechnologhUlsan 44919Republic of Korea Clarendon Laboratory Department of PhysicsUniversity of OxfordParks RoadOxford OX13PUUK Centre for Quantum Technologies National University of SingaporeScience Drive 2Singapore 117543Singapore

Inorganic perovskite lasers are of particular interest,with much recent work focusing on Fabry-P6rot cavity-forming *** demonstrate the direct observation of lasing from transverse electromagnetic(TEM)modes with a long coherence time-9.5ps in coupled CsPbBr_(3) quantum dots,which dispense with an external cavity resonator and show how the wavelength of the modes can be controlled via two independent *** the pump power allowed us tofine-tune the TEM mode structure to the emission wavelength,thus providing a degree of control over the properties of the lasing *** temperature-tuning provided an additional degree of control over the wavelength of the lasing peak,importantly,maintained a constant full width at half maximum(FWHM)over the entire tuning range without mode-hopping.

关键词： perovskite quantum dots coherent lasing transverse electromagnetic mode stimulated emission

Generalized Anxiety and Major Depressive symptoms of General Public in south Korea during the Early COVID-19 Pandemic

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International Journal of Mental Health Promotion 2021年第3期23卷 303-317页

作者： Kye s.kim Peter M.Kang He sook N.kim Department of Medicine Beth Israel Deaconess Medical Center and Harvard Medical SchoolBostonMA 02215USA Department of Child&Family studies Yonsei UniversitySeoul03722South Korea

The extent of viral spread and strategies in dealing with the COVID-19 pandemic have been different in each *** are overall increased mental health concerns in many countries but it is unclear what the general public individuals who do not have heighten vulnerability to stressors for existing mental diseases or significant physical illnesses were experiencing during the *** evaluated the stressors and mental health of general public in south Korea that has a relatively low confirmed cases and *** on the on-line survey questions were used to assess the mental and physical symptoms in association with individuals’reported *** with the symptoms of the generalized anxiety disorder(GAD)were reported in 58.9%,and major depression(MD)in 23.2%,mostly in minimal to mild degrees,cut-off scores of 5 and 10,respectively by the validated screening tools,GAD-7 and *** GAD and MD symptoms were in 21.5%of the *** total number of stress had significant association with the scores of GAD-7,PHQ-9,physical symptoms,sleep difficulties and resilience(pscores were also associated with sleep difficulties(psing young children(pscores were associated with sleep difficulties,job-dissatisfaction,and educational level(ps of the study include small sample size,usage of smartphone or email,potential under-reporting by stigma in the socio-cultural context and evolving nature of *** conclude that keeping careful watch for mental symptoms,stressors,sleep difficulties and other physical symptoms are important even for the individuals without previous mental illnesses during the pandemic era.

关键词： Generalized anxiety disorder symptoms major depression symptoms sleep difﬁculties physical symptoms pandemic stressors south Korea generalized anxiety disorder-7(GAD-7) patient health questionnaire-9(PHQ-9)

Atrial fibrillation in older adults with cancer

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Journal of Geriatric Cardiology 2022年第1期19卷 1-8页

作者： Manish Kumar Nerea Lopetegui-Lia Christina Al Malouf Mansour Almnajam Patrick P.Coll Agnes s.kim Department of Medicine Pat and Jim Calhoun Cardiology CenterUniversity of Connecticut School of MedicineFarmingtonCT 06030USA Department of Hematology and Oncology Cleveland ClinicOhio 44195USA De-partment of Cardiology Mount Sinai Hospital/Icahn School of MedicineNew York 10029USA Department of Fam-ily Medicine UConn Center of AgingUniversity of ConnecticutSchool of MedicineFarmingtonCT 06030USA

Cancer and atrial fibrillation(AF)are common co-morbid conditions in older *** cancer and cancer treatment increase the risk of developing new AF which increases morbidity and *** rate and rhythm control along with anticoagulation therapy remain the mainstay of treatment of AF in older adults with both cancer and *** to the treatment may be necessary because of drug interactions with concurrent *** and old age increase the risk of both,thromboembolism and *** risk of these complications is further enhanced by concomitant cancer therapy,frailty,poor nutrition status and,coexisting geriatric ***,careful attention needs to be given to the risks and benefits of using anticoagulant *** review focuses on the management of AF in older patients with cancer,including at the end-of-life care.

关键词： fibrillation Cancer chemotherapy

Inspection of maleic anhydride in starch powder using line-scan hyperspectral Raman chemical imaging technique

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International Journal of Agricultural and Biological Engineering 2018年第6期11卷 120-125页

作者： Jianwei Qin Moon s.kim Kuanglin Chao Lisa Bellato Walter F.schmidt Byoung-Kwan Cho Min Huang UsDA/ARs Environmental Microbial and Food safety Laboratory Beltsville Agricultural Research Center10300 Baltimore Ave.BeltsvilleMD 20705USA Department of Production Engineering Municipal Education Foundation of Piracicaba(FUMEP)-Piracicaba’s School of Engineering560 Monsenhor Martinho Salgot Ave.PiracicabaSP 13414-040Brazil Department of Biosystems Machinery Engineering College of Agricultural and Life ScienceChungnam National University99 Daehak-roYuseoung-guDaejeon 305-764South Korea Key Laboratory of Advanced Process Control for Light Industry(Ministry of Education) Jiangnan University1800 Lihu AvenueWuxi 214122JiangsuChina

Excessive use of maleic anhydride(MAN)in starch production is potentially harmful for consumers’*** study presents a macro-scale Raman chemical imaging method for detection and quantification of MAN particles mixed in starch *** was mixed into corn starch at eight concentration levels from 50 ppm to 6400 ppm(w/w).Each mixture was put in a sample holder with a 150 mm×100 mm area and a 2 mm depth to create a large surface and a thin layer of the powdery sample for inspection.A 30 W 785 nm line laser was projected on the sample surface,from which hyperspectral images were obtained by a line-scan Raman imaging system with a spatial resolution of 0.2 *** signals generated by laser-sample interactions were eliminated by a mathematical baseline correction method.A unique Raman peak was selected at 1839 cm-1 for the MAN detection,at which single-band fluorescence-corrected images were extracted from the mixture of each concentration and used to generate chemical images for MAN detection and *** MAN detection limit was estimated at 100 ppm based on the Raman imaging measurement *** concentrations of the MAN in the chemical images were found linearly correlated with mass concentrations of the MAN particles in the starch powder,suggesting the Raman chemical imaging method has the potential for quantitative detection of the MAN in the starch-MAN mixtures.

关键词： Raman spectroscopy chemical imaging starch adulteration food authentication

Enhanced photoluminescence quantum yield of MAPbBr3 nanocrystals by passivation using graphene

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Nano Research 2020年第4期13卷 932-938页

作者： Youngsin Park Atanu Jana Chang Woo Myung Taeseung Yoon Geungsik Lee Claudius C.Kocher Guanhua Ying Vitaly Osokin Robert A.Taylor Kwang s.kim school of Natural science Ulsart National Institute of Science and TechnologhUlsan 44919Republic of Korea 2 Clarendon LaboratoryDepartment of PhysicsUniversity of OxfordParks RoadOxford0X13PUUK

Diminishing surface defect states in perovskite nancx^rystals is a highly challenging subject for enhancing optoelectronic device *** synthesized organic/inorganic lead-halide perovskite MAPbBr3(MA=methylammonium)clusters comprising nanocrystals with diameters ranging between 20 and 30 nm and characterized an enhanced photoluminescence(PL)quantum yield(as much as^7 times)by encapsulating the MAPbBr3 with graphene(Gr).The optical properties of MAPbBr3 and Gr/MAPbBr3 were investigated by temperature-dependent micro-PL and time-resolved PL *** functional theory calculations show that the surface defect states in MAPbBr3 are removed and the optical band gap is reduced by a 0.15 eV by encapsulation with graphene due to partial restoration of lattice distortions.

关键词： perovskite nanocluster photoluminescence surface passivation graphene density functional theory calculations

study and Manufacture of Gain Flattened s-band DistributedDispersion Compensation fiber Raman amplifier

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Study and Manufacture of Gain Flattened S-band DistributedDi...