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Unravelling the role of the combined effect of metallic charge transfer channel and SiO_(x) overlayer in the Zr/Si-Fe_(2)O_(3):Au:SiO_(x) nanorod arrays to boost photoelectrochemical water splitting

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Journal of Energy Chemistry 2024年第3期90卷 370-379,I0009页

作者： Tae sik Koh Periyasamy Anushkkaran Love Kumar Dhandole Mahadeo A.Mahadik Weon-sik Chae Hyun Hwi Lee Sun Hee choi Jum Suk Jang Division of Biotechnology SafetyEnvironment and Life Science InstituteCollege of Environmental and Bioresource SciencesJeonbuk National UniversityIksan 54896Republic of Korea Department of Integrative Environmental Biotechnology College of Environmental and Bioresource SciencesJeonbuk National UniversityIksan 54596Republic of Korea Extreme Materials Research Center Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Daegu Center Korea Basic Science InstituteDaegu 41566Republic of Korea Pohang Accelerator Laboratory Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea

Hematite(α-Fe_(2)O_(3)) based photoanodes have been extensively studied due to various intriguing features that make them viable candidates for a photoelectrochemical(PEC) water splitting ***,we propose a Zr-doped Fe_(2)O_(3) photoanode decorated with facilely spin-coated Au nanoparticles(NPs) and microwave-assisted attached Si co-doping in conjunction with a SiO_(x) overlayer that displayed a remarkable photocurrent density of 2.01 mA/cm^(2) at 1.23 V *** kinetic dynamics at the photoelectrode/-electrolyte interface was examined by employing systematic electrochemical *** Au NPs played a dual role in increasing PEC water ***,the Schottky interface that was formed between Au NPs and Zr-Fe_(2)O_(3) lectrode ensured the prevention of electron flow from the photoanode to the metal,increasing the number of available charges as well as suppressing surface charge ***,Au extracted photoholes from the bulk of the Zr-Fe_(2)O_(3) and transported them to the outer SiO_(x) overlayer,while the SiO_(x) overlayer efficiently collected the photoholes and promoted the hole injection into the ***,Si co-doping enhanced bulk conductivity by reducing bulk charge transfer resistance and improving charge carrier *** study outlines a technique to design a metallic charge transfer path with an overlayer for solar energy conversion.

关键词： Hematite Microwave attachment Au nanoparticles SiO_(x) overlayer Water splitting

玻璃制作工具用5%ZrO_2纳米铂材的机械合金化制备(英文)

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Transactions of Nonferrous Metals Society of China 2014年第S1期24卷 99-105页

作者： Taek-Kyun JUNG Dong-Woo JOH Seung-Yub LEE myung-sik choi Soong-Keun HYUN Hyo-Soo LEE Korea Institute of Industrial Technology 7-47 Songdo-dong Yenosu-gu Incheon 406-840 Korea Department of Applied Physics and Applied Mathematics Columbia University School of Materials Science and Engineering Inha University 253 Yonghyun-Dong Incheon 405-751 Korea

对机械合金化制备的玻璃工业中用作结构零件的Pt-5%ZrO2(体积分数)的进行表征。通过锆丝电爆炸法制备氧化锆(ZrO2)纳米颗粒(粒径<100 nm),并在室温下与铂粉(粒径<44?m)球磨2~72 h。普通球磨至48 h时,铂粒径遵循经典的递减趋势,至72 h时... 详细信息

对机械合金化制备的玻璃工业中用作结构零件的Pt-5%ZrO2(体积分数)的进行表征。通过锆丝电爆炸法制备氧化锆(ZrO2)纳米颗粒(粒径<100 nm),并在室温下与铂粉(粒径<44?m)球磨2~72 h。普通球磨至48 h时,铂粒径遵循经典的递减趋势,至72 h时观测到颗粒团聚现象。晶粒尺寸演变规律与颗粒尺寸规律相似,48 h后减至50 nm左右。但是,铂晶粒的均方根应变规律相反,一直在增长,直至48 h时得到最大值,然后出现弛豫。粉末球磨48 h后,采用放电等离子体烧结制成块体。根据测量得到烧结体的质量损失表明:合金虽然相对密度较低,但有较好的热稳定性。

关键词：铂氧化锆纳米粒子电丝爆炸法机械合金化

Absence of enhancement in a lesion does not preclude primary central nervous system T-cell lymphoma:A case report

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World Journal of Clinical Cases 2024年第2期12卷 374-382页

作者： Chan-Seop Kim Chi-Hoon choi Kyung sik Yi Yook Kim Jisun Lee Chang Gok Woo Young Hun Jeon Department of Radiology Chungbuk National University HospitalChungbuk National University College of MedicineCheongju-si 28644Chungcheongbuk-doSouth Korea Department of Pathology Chungbuk National University HospitalChungbuk National University College of MedicineCheongju-si 28644Chungcheongbuk-doSouth Korea Department of Radiology Seoul National University HosptialSeoul 03080South Korea

BACKGROUND Primary central nervous system lymphoma(PCNSL)is a non-Hodgkin lymphoma that originates in the central nervous system(CNS)and is exclusively limited to the *** most PCNSLs are diffuse large B-cell lymphomas,primary CNS T-cell lymphomas(PCNSTLs)are *** typically demonstrate some degree of enhancement on contrast-enhanced magnetic resonance imaging(MRI).To the best of our knowledge,non-enhancing PCNSTL has not been reported *** SUMMARY A 69-year-old male presented to the neurology department with complaints of mild cognitive impairment and gradual onset of left lower leg weakness over a span of two *** MRI showed asymmetric T2-hyperintense lesions within the *** enhancement was observed on the contrast-enhanced T1 *** initial diagnosis was neuro-Behçet’s *** high-dose steroid therapy,no alterations in the lesions were identified on initial *** patient’s symptoms deteriorated *** MRI performed one month after the initial scan revealed an increased lesion ***,brain biopsy confirmed the diagnosis of *** patient underwent definitive combined ***,the patient developed bacteremia and died of septic shock approximately three months after *** The absence of enhancement in the lesion did not rule out PCNSTL.A biopsy approach is advisable for pathological confirmation.

关键词： Central nervous system neoplasms Non-Hodgkin Lymphoma T-cell Lymphoma Primary central nervous system lymphoma Primary central nervous system T-cell lymphoma Case report

Ex situ aging effect on sulfonated poly(ether ether ketone) membrane:Hydration-dehydration cycling and hydrothermal treatment

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Journal of Energy Chemistry 2022年第7期31卷 583-592,I0014页

作者： Seung-Young choi Kyeong sik Jin Polymer&Materials Chemistry Department of ChemistryLund UniversitySE-22100Sweden Center for Hydrogen·Fuel Cell Research Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Pohang Accelerator Laboratory Pohang University of Science and Technology(POSTECH)PohangKyungbuk 37673Republic of Korea

Prolonged hydrothermal treatment for sulfonated poly(ether ether ketone) membranes induces mechanical degradation and developing hydrophilic-hydrophobic phase separation, simultaneously. The enhanced phase separation provides incremental proton conductivity to the membranes, whereas mechanical degradation drastically reduces device stability. On this basis, we describe here the effects of two different ex situ aging processes on sulfonated poly(ether ether ketone) membranes: hydrationdehydration cycling and prolonged hydrothermal treatment. Both aged membranes exhibited enhanced phase separation under the hydrated conditions, as characterized by small angle X-ray ***, when the aged membranes were dried again, the nanostructure of the membranes aged via the hydration-dehydration cycling was recoverable, whereas that of the membranes aged via prolonged hydrothermal treatment was irreversible. Furthermore, the two differently aged membranes showed clear differences in thermal, mechanical, and electrochemical properties. Finally, we implemented both aged membranes in fuel cell application. The sample aged via hydration-dehydration cycling maintained its improved cell performance, whereas the sample aged via hydrothermal treatment showed drastically reduced cell performance after durability test for 50 h.

关键词： Sulfonated poly(ether ether ketone) Humidity cycle test Ex situ aging Proton exchange membrane Fuel cell

Gradient Si-and Ti-doped Fe_(2)O_(3) hierarchical homojunction photoanode for efficient solar water splitting:Effect of facile microwave-assisted growth of Si-FeOOH on Ti-FeOOH nanocorals

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Journal of Energy Chemistry 2023年第2期77卷 27-37,I0002页

作者： Tae sik Koh Periyasamy Anushkkaran Weon-sik Chae Hyun Hwi Lee Sun Hee choi Jum Suk Jang Division of Biotechnology College of Environmental and Bioresource SciencesJeonbuk National UniversityIksan 54596Republic of Korea Daegu Center Korea Basic Science InstituteDaegu 41566Republic of Korea Pohang Accelerator Laboratory Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea

The construction of a homojunction is an effective approach for addressing issues such as slow charge separation and charge-transfer kinetics in *** the present work,we designed a gradient Si-and Ti-doped Fe_(2)O_(3) homojunction photoanode to improve the photoelectrochemical(PEC)performance of a Ti-doped Fe_(2)O_(3) ***-FeOOH nanocorals were synthesized using a hydrothermal process,and Si-FeOOH was grown on Ti-FeOOH nanocorals using a rapid and facile microwaveassisted(MW)*** varying the MW irradiation time,the thickness of the Si/Ti:Fe_(2)O_(3) photoanode was adjusted and an optimized 3-Si/Ti:Fe_(2)O_(3) photoelectrode was achieved with a significantly enhanced photocurrent density(1.37 mA cm^(-2) at 1.23 V ***)and a cathodic shift of the onset potential(150 mV)compared with that of bare Ti-Fe_(2)O_(3).This enhanced PEC performance can be ascribed to homojunction formation and Si gradient *** Si dopant increased the donor concentration and the formation of a homojunction improved the intrinsic built-in electric field,thereby promoting charge separation and charge ***,the as-formed homojunction passivated the surfacetrapping states,consequently improving the charge transfer efficiency(60%at 1.23 VRHE)at the photoanode/electrolyte *** findings could pave the way for the microwave-assisted fabrication of diverse efficient homojunction photoanodes for PEC water splitting applications.

关键词： Homojunction Microwave-assisted Hematite Gradient doping PEC water splitting

MicroRNA miR-252-5p regulates the Notch signaling pathway by targeting Rab6 in Drosophila wing development

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Insect Science 2023年第5期30卷 1431-1444页

作者： Do-Hwan Lim Min-Seok choi Ji Won Jeon Young sik Lee School of Systems Biomedical Science Soongsil UniversitySeoulRepublic of Korea College of Life Sciences and Biotechnology Korea UniversitySeoulRepublic of Korea Institute of Animal Molecular Biotechnology Korea UniversitySeoulRepublic of Korea

The Notch signaling pathway plays a central role in the development of various ***,dysregulation of microRNAs(miRNAs),which are crucial regulators of gene expression,can disrupt signaling pathways at all stages of *** Notch signaling is involved in wing development in Drosophila,the mechanism underlying miRNA-based regulation of the Notch signaling pathway is ***,we report that loss of Drosophila miR-252 increases the size of adult wings,whereas the overexpression of miR-252 in specific compartments of larval wing discs leads to patterning defects in the adult *** miR-252 overexpression-induced wing phenotypes were caused by aberrant Notch signaling with intracellular accumulation of the full-length Notch receptor during development,which could be due to defects in intracellular Notch trafficking associated with its recycling to the plasma membrane and autophagy-mediated ***,we identified Rab6 as a direct target of miR-252-5p;Rab6 encodes a small Ras-like GTPase that regulates endosomal trafficking *** with this finding,RNAi-mediated downregulation of Rab6 led to similar defects in both wing patterning and Notch ***,co-overexpression of Rab6 completely rescued the wing phenotype associated with miR-252 overexpression,further supporting that Rab6 is a biologically relevant target of miR-252-5p in the context of wing ***,our data indicate that the miR-252-5p-Rab6 regulatory axis is involved in Drosophila wing development by controlling the Notch signaling pathway.

关键词： Drosophila miR-252-5p Notch signaling Rab6 wing development

Estimating the instantaneous reproduction number(R_(t))by using particle filter

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Infectious Disease Modelling 2023年第4期8卷 1002-1014页

作者： Yong Sul Won Woo-sik Son Sunhwa choi Jong-Hoon Kim National Institute for Mathematical Sciences DaejeonSouth Korea International Vaccine Institute SeoulSouth Korea

Background:Monitoring the transmission of coronavirus disease 2019(COVID-19)requires accurate estimation of the effective reproduction number(Rt).However,existing methods for calculating Rt may yield biased estimates if important real-world factors,such as delays in confirmation,pre-symptomatic transmissions,or imperfect data observation,are not ***:To include real-world factors,we expanded the susceptible-exposed-infectiousrecovered(SEIR)model by incorporating pre-symptomatic(P)and asymptomatic(A)states,creating the SEPIAR *** utilizing both stochastic and deterministic versions of the model,and incorporating predetermined time series of Rt,we generated simulated datasets that simulate real-world challenges in estimating *** then compared the performance of our proposed particle filtering method for estimating Rt with the existing EpiEstim approach based on renewal ***:The particle filtering method accurately estimated Rt even in the presence of data with delays,pre-symptomatic transmission,and imperfect *** evaluating via the root mean square error(RMSE)metric,the performance of the particle filtering method was better in general and was comparable to the EpiEstim approach if perfectly deconvolved infection time series were provided,and substantially better when Rt exhibited short-term fluctuations and the data was right ***:The SEPIAR model,in conjunction with the particle filtering method,offers a reliable tool for predicting the transmission trend of COVID-19 and assessing the impact of intervention *** approach enables enhanced monitoring of COVID-19 transmission and can inform public health policies aimed at controlling the spread of the disease.

关键词： Particle filter Sequential Monte Carlo Effective reproduction number COVID-19 Transmission model Compartment model

Usefulness of transcatheter arterial embolization for eighty-three patients with secondary postpartum hemorrhage:Focusing on difference in angiographic findings

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World Journal of Clinical Cases 2023年第15期11卷 3471-3480页

作者： Bong Man Kim Gyeong sik Jeon Min Jeong choi Nam-Soo Hong Department of Radiology Dankook University HospitalDankook University College of MedicineCheonan-si 31116Chungcheongnam-doSouth Korea Department of Radiology CHA Bundang Medical CenterCollege of MedicineCHA UniversitySeongnam-si 13496Gyeonggi-doSouth Korea Department of Preventive Medicine School of MedicineKyungpook National UniversityDaegu 41944South Korea

BACKGROUND Transcatheter arterial embolization(TAE)has been widely used as an effective and a safe treatment method and was often used as an alternative to the surgical management,but there are limited studies on the efficacy and the safety for patients undergoing their secondary postpartum hemorrhage(PPH).AIM To evaluate the usefulness of TAE for secondary PPH focusing on the angiographic *** We conducted a research from January 2008 to July 2022 on all 83 patients(mean:32 years,range:24-43 years)presented with secondary PPH and they were treated with TAE in two university *** medical records and angiography were retrospective reviewed in order to evaluate the patients’characteristics,delivery details,clinical status and peri-embolization management,angiography and embolization details,technical/clinical success and *** group with active bleeding sign and the group without it were also compared and *** On angiography,46(55.4%)patients showed active bleeding signs such as contrast extravasation(n=37)or pseudoaneurysm(n=8)or both(n=1),and 37(44.6%)patients showed non-active bleeding signs such as only spastic uterine artery(n=2)or hyperemia(n=35).In the active bleeding sign group there were more multiparous patients,low platelet count,prothrombin time prolongation,and high transfusion *** technical success rates were 97.8%(45/46)in active bleeding sign group and 91.9%(34/37)in non-active bleeding sign group,and the overall clinical success rates were 95.7%(44/46)and 97.3%(36/37).An uterine rupture with peritonitis and abscess formation occurred to one patient after the embolization,therefore hysterostomy and retained placenta removal were performed which was a major *** TAE is an effective and a safe treatment method for controlling secondary PPH regardless of angiographic findings.

关键词： Postpartum hemorrhage Angiography Transcatheter arterial embolization Pseudoaneurysm Nbutylcyanoacrylate

Improving toughness of medium-Mn steels after friction stir welding through grain morphology tuning

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Journal of Materials Science & Technology 2022年第23期118卷 243-254页

作者： Mun sik Jeong Tak Min Park Dong-Il Kim Hidetoshi Fujii Hye Ji Im Pyuck-Pa choi Seung-Joon Lee Jeongho Han Division of Materials Science and Engineering Hanyang UniversitySeoul 04763Republic of Korea Department of Advanced Materials Engineering Korea Polytechnic UniversitySiheung 15073Republic of Korea Joining and Welding Research Institute Osaka UniversityOsaka 567-0047Japan Department of Materials Science and Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea Department of Materials Science and Engineering Northwestern UniversityEvanstonIL 60208USA

This work demonstrated the viability of friction stir welding for the welding of medium-Mn steels when used as cryogenic vessel materials for liquefied gas *** used an intercritically annealed Fe-7 Mn-0.2 C-3 Al(wt.%)steel with a dual-phase(α'martensite andγ_(R) retained austenite)nanolaminate structure as a base material and systematically compared its microstructure and impact toughness after friction stir and tungsten inert gas *** friction stir welded specimen exhibited a large amount ofγ_(R) phase owing to a relatively low temperature during welding,whereas the tungsten inert gas welded specimen comprised only theα'***,the friction stir welded steel exhibited a tuned morphology of nanoscale globular microstructure at the weld zone and did not exhibit any prior austenite grain boundary due to active recrystallization caused by deformation during *** preserved fraction ofγ_(R) and morphological tuning in the weldment improved the impact toughness of the friction stir welded steel at low *** the steel processed by tungsten inert gas welding,the notch crack propagated rapidly along the prior austenite grain boundaries-weakened by Mn and P segregations-resulting in poor impact ***,the friction stir welded steel exhibited a higher resistance against notch crack propagation due to the slow crack propagation along the ultrafine ferrite/ferrite(α/α)interfaces,damage tolerance by the active transformation-induced plasticity from the large amount ofγR,and enhanced boundary cohesion by suppressed Mn and P segregations.

关键词： Charpy impact test Transformation-induced plasticity Friction stir welding Phase stability Medium-Mn steel