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Shape-controlled Pt nanocubes directly grown on carbon supports and their electrocatalytic activity toward methanol oxidation

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Science Bulletin 2017年第13期62卷 943-949页

作者： Hee Jin Kim Bibi Ruqia Mi Sung Kang Su Bin Lim Ran choi Ki Min nam Won Seok Seo Gaehang Lee Sang-Il choi Department of Chemistry and Green-Nano Materials Research Center Kyungpook National University Department of Chemistry KAIST Department of Chemistry Mokpo National University Department of Chemistry Sogang University Korea Basic Science Institute(KBSI) and University of Science and Technology

Synthesis of shape-controlled Pt nanocrystals is substantial and important for enhancing chemical and electrochemical ***,the removal of capping agents,shape-controlling chemicals,on Pt surfaces is essential prior to conducting the catalytic *** we report a facile one-pot synthesis of Pt nanocubes directly grown on carbon supports(Pt nanocubes/C) with modulating the kinetic reaction factors for shaping the nanocrystals,but without adding any capping agents for preserving the clean Pt ***-dispersed Pt nanocubes/C shows enhanced activity and long-term stability toward methanol oxidation reaction compared to the commercial Pt/C catalyst.

关键词： Platinum Nanocube Shape-control Kinetic product Methanol oxidation

Room-temperature sputtered electrocatalyst WSe2 nanomaterials for hydrogen evolution reaction

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Journal of Energy Chemistry 2020年第8期29卷 107-111,I0004页

作者： Jae Hyeon nam Myeong Je Jang Hye Yeon Jang Woojin Park Xiaolei Wang Sung Mook choi Byungjin Cho Department of Advanced Material Engineering Chungbuk National UniversityChungdae-ro 1Seowon-GuCheongjuChungbuk 28644Republic of Korea Surface Technology Department Korea Institute of Materials Science797 ChangwonDaeroSungsan-guChangwon 51508Republic of Korea Advanced Materials Engineering Korea University of Science and Technology(UST)217 Gajeong-roYuseong-guDaejeon 34113Republic of Korea Department of Chemical and Materials Engineering University of Alberta9211116 Street NWEdmontonAlberta T6C 1H9Canada

The low-temperature physical vapor deposition process of atomically thin two-dimensional transition metal dichalcogenide(2D TMD) has been gaining attention owing to the cost-effective production of diverse electrochemical catalysts for hydrogen evolution reaction(HER) applications. We, herein, propose a simple route toward the cost-effective physical vapor deposition process of 2D WSe2 layered nanofilms as HER electrochemical catalysts using RF magnetron sputtering at room temperature(<27℃). By controlling the variable sputtering parameters, such as RF power and deposition time, the loading amount and electrochemical surface area(ECSA) of WSe2 films deposited on carbon paper can be carefully determined. The surface of the sputtered WSe2 films are partially oxidized, which may cause spherical-shaped particles. Regardless of the loading amount of WSe2, Tafel slopes of WSe2 electrodes in the HER test are narrowly distributed to be ~120–138 mV dec-1, which indicates the excellent reproducibility of intrinsic catalytic activity. By considering the trade-off between the loading amount and ECSA, the best HER performance is clearly observed in the 200 W-15 min sample with an overpotential of 220 mV at a current density of 10 mA cm-2. Such a simple sputtering method at low temperature can be easily expanded to other 2D TMD electrochemical catalysts, promising potentially practical electrocatalysts.

关键词： Two dimensional nanomaterials Sputtering WSe2 nanofilm Electrocatalyst Hydrogen evolution reaction

A Frequency Selective Surface Loaded UWB Antenna for High Gain Applications

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Computers, Materials & Continua 2022年第12期73卷 6169-6180页

作者： Wahaj Abbas Awan Do Min choi Niamat Hussain Issa Elfergani Seong Gyoon Park nam Kim Department of Information and Communication Engineering Chungbuk National UniversityCheongju28644Korea Instituto de Telecomunicacoes Campus Universitário de Santiago 3810-193Aveiro Portugal School of Engineering and Informatics Bradford UniversityBradfordBD71DPU.K Department of Information and Communication Engineering Kongju National UniversityKongjuKorea

This paper presents the design of wideband and high gainFrequency Selective Surface(FSS)loaded antenna for ultra-wideband(UWB)wireless applications requiring *** antenna consists of a monopole and an FSS ***,a conventional rectangular monopole antenna is modified using slot and stub to achieve wide operational bandwidth and size *** modified antenna shows 50%miniaturization compared to a primary rectangular monopole,having a wide impedance bandwidth of 3.6-11.8 ***,an FSS is constructed by the combination of circular and square ring *** FSS array consisting of 8×8-unit cells are integrated with the antenna as a reflector to enhance the performance of the proposed miniaturized UWB *** loading of FSS results in an improvement of at least 4 dBi gain in the entire operational ***,the antenna’s bandwidth is also increased at the lower frequency band due to the presence of the FSS.A prototype of the antenna is fabricated and tested to verify the simulation *** simulation and measurement results show that the antenna offers a wideband-10 dB impedance bandwidth ranging from 2.55-13GHz with a stable peak gain of 8.6 dBi and retains the radiation pattern stability.

关键词： FSS UWB antenna high gain antenna FSS reflector

Long-term radiofrequency electromagnetic fields exposure attenuates cognitive dysfunction in 5×FAD mice by regulating microglial function

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Neural Regeneration Research 2023年第11期18卷 2497-2503页

作者： Yeonghoon Son Hye-Jin Park Ye Ji Jeong Hyung-Do choi nam Kim Hae-June Lee Division of Radiation Biomedical Research Korea Institute of Radiological&Medical SciencesSeoulKorea Department of EMF Research Team Radio and Broadcasting Technology LaboratoryElectronics and Telecommunications Research InstituteDaejonKorea School of Electrical and Computer Engineering Chungbuk National UniversityCheongjuKorea

We have previously found that long-term effects of exposure to radiofrequency electromagnetic fields in 5xFAD mice with severe late-stage Alzheimer’s disease reduced both amyloid-βdeposition and glial activation,including *** examine whether this therapeutic effect is due to the regulation of activated microglia,we analyzed mic roglial gene expression profiles and the existence of microglia in the brain in this study.5xFAD mice at the age of 1.5 months were assigned to sham-and radiofrequency electromagnetic fields-exposed groups and then animals were exposed to 1950 MHz radiofrequency electromagnetic fields at a specific absorption rate of 5 W/kg for 2 hours/day and 5 days/week for 6 *** conducted behavioral tests including the object recognition and Y-maze tests and molecular and histopathological analysis of amyloid precursor protein/a myloid-beta metabolism in brain *** confirmed that radiofrequency electromagnetic field exposure for 6 months ameliorated cognitive impairment and amyloid-β*** expression levels of Iba1(pan-microglial marker)and colony-stimulating factor 1 receptor(CSF1R;regulates microglial prolife ration)in the hippocampus in 5xFAD mice treated with radiofrequency electromagnetic fields were significantly reduced compared with those of the sham-exposed ***,we analyzed the expression levels of genes related to mic rogliosis and microglial function in the radiofrequency electromagnetic fields-exposed group compared to those of a CSF1R inhibitor(PLX3397)-treated *** radiofrequency electromagnetic fields and PLX3397 suppressed the levels of genes related to microgliosis(Csf1r,CD68,and Ccl6)and pro-inflammatory cytokine interleukin-1β.N otably,the expression levels of genes related to mic roglial function,including Trem2,Fcgr1α,Ctss,and Spi1,were decreased after long-term radiofrequency electromagnetic field exposure,which was also observed in response to microglial suppression by *** res

关键词： 5×FAD Alzheimer’s disease CSF1R long term exposure microglial function neuroinflammation radiofrequency electromagnetic fields therapeutic effect

Protective Effect of Brassica napus *** against Inflammation Response in RAW 264.7 Cells

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Chinese Journal of Integrative Medicine 2021年第4期27卷 273-279页

作者： Su-Hyeon Cho Song Rae Kim Myeong Seon Jeong Miri choi SeonJu Park Kil-nam Kim Chuncheon Center Korea Basic Science InstituteChuncheon(24341)Republic of Korea

Objective:To demonstrate the anti-inflammatory activity of Brassica napus ***(BNH)in lipopolysaccharide(LPS)-stimulated RAW 264.7 ***:Composition analysis of BNH was conducted via gas chromatography-mass spectrometry after BNH were *** nitric oxide(NO)production was measured using the Griess *** E2(PGE2)production was evaluated with enzyme-linked immunosorbent *** effects of BNH on LPS-induced pro-inflammatory enzymes including inducible nitric oxide synthase(iNOS)and cyclooxygenase-2(COX-2)were evaluated using Western blot ***,phosphorylation of nuclear factor-kappa B(N F-k B)and nuclear translocation of N F-k B p65 were evaluated with Western blot analysis and immunofluorescence staining,***:Compared with LPS-stimulated cells,BNH markedly decreased the generation of NO and PGE_(2)in LPS-stimulated RAW 264.7 cells(P<0.01 or P<0.05).Moreover,BNH inhibited protein levels of iNOS and COX-2(P<0.01).Phosphorylation of NF-k B and nuclear translocation of NF-k B p65 was significantly inhibited by BNH(P<0.01 or P<0.05).Conclusion:The anti-inflammatory activities of BNH were mediated via blockage of the N F-k B signaling pathways in LPS-stimulated RAW 264.7 cells.

关键词： Brassica napus L. inflammation lipopolysaccharide RAW 264.7 cells hydrosols

A population-based case-crossover study of polyethylene glycol use and acute renal failure risk in the elderly

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World Journal of Gastroenterology 2011年第5期17卷 651-656页

作者： nam-Kyong choi Yoosoo Chang Sun-Young Jung Yu-Kyong choi Joongyub Lee Jin-Ho Lee Ju-Young Kim Byung-Joo Park Department of Preventive Medicine Seoul National University College of MedicineSeoul 110-799South Korea Medical Research Center Seoul National UniversitySeoul 110-799South Korea Department of Occupational Medicine Health Screening CenterKangbuk Samsung HospitalSungkyunkwan University College of MedicineSeoul 110-746South Korea National Evidence-Based Healthcare Collaborating Agency Seoul 110-450South Korea Department of Internal Medicine Gumi HospitalGumi 730-909South Korea Medical Research Collaborating Center Seoul National University Hospital Seoul National University College of Medicine Seoul 110-799South Korea Department of Internal Medicine Dongguk University Ilsan HospitalSchool of MedicineDongguk UniversityGoyang 410-733South Korea Department of Family Medicine Health Promotion CenterSeoul National University Bundang HospitalBundang 463-707South Korea

AIM:To evaluate the possibility of an association between polyethylene glycol(PEG) and acute renal failure(ARF) in elderly patients using a health insurance claims ***:We conducted a population-based casecrossover study using information obtained from Korean Health Insurance Review and Assessment Service(HIRA) claims from January 1,2005 to December 31,2005(Seoul,Korea).The study population consisted of elderly patients who received PEG prior to experiencing their first ARF-related hospitalization from April 1,2005 to December 31,*** each patient,one case and two control periods were *** use in a 2-or 4-wk window period prior to hospitalization for ARF was compared with PEG use in two earlier 2-or 4-wk control window *** logistic regression analysis was used to estimate odds ratios(ORs) and 95% CI,adjusting for concomitant uses of diuretics,angiotensin converting enzyme inhibitors,non-steroidal anti-inflammatory drugs,antibiotics,anti-cancer drugs,and contrast ***:Within the HIRA database which contained 1 093 262 elderly patients,1156 hospitalized ARF cases were *** these cases,PEG was prescribed to 17(1.5%) patients before *** adjusted ORs when applying the 2-and 4-wk window periods were 0.4(95% CI:0.03-5.24) and 2.1(95% CI:0.16-27.78),***:No increased risk of ARF was found in elderly PEG ***,based on the limited number of study subjects,further analysis should be performed to confirm these results.

关键词： Polyethylene glycol Acute renal failure Adverse drug reaction Health insurance claims data-base Case-crossover

Biopeptides of Pyropia yezoensis and their potential health benefits: A review

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Asian Pacific Journal of Tropical Biomedicine 2021年第9期11卷 375-384页

作者： Sivakumar Allur Subramaniyan Naziya Begum Sung Jae Kim Youn Hee choi Taek-Jeong nam Institute of Fisheries Sciences Pukyong National UniversityBusan 46041South Korea Department of Chemistry College of Natural and computational sciencesDebre Berhan UniversityDebye BerhanP.O.Box-445 Ethiopia Department of Orthopaedic Surgery Dongtan Sacred Heart HospitalHallym University College of MedicineHwaseongRepublic of Korea Department of Marine Bio-Materials&Aquaculture Pukyong National UniversityBusan 48513South Korea

Pyropia yezoensis(***)is a popular species of red algae that are commercially cultivated and consumed in East Asia,China,Japan,and *** high protein content of *** provides a source of multiple bioactive peptides exhibiting antioxidant,anti-inflammatory,antihypertensive,anticancer,tissue healing,immunomodulatory,and anticoagulant ***,many other biologically active substances in ***,including carbohydrates,lipids,dietary fibers,and polyphenols,have shown potential health benefits and are important in both the food and agriculture *** review provides a detailed summary of researches over the last decade on the biological and medicinal properties of bioactive *** information was extracted from various electronic resources,including Google Scholar,PubMed,MEDLINE,and Google Patents.

关键词： Red algae Pyropia Bioactive peptides Human health

Regional Distribution of Perceived Temperatures Estimated by the Human Heat Budget Model (the Klima-Michel Model) in South Korea

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Advances in Atmospheric Sciences 2009年第2期26卷 275-282页

作者： Jiyoung KIM kyu Rang KIM Byoung-Cheol choi Dae-Geun LEE Jeong-Sik KIM National Institute of Meteorological Research Korea Meteorological Administration Korea Global Atmosphere Watch Center Korea Meteorological Administration

The regional distribution of perceived temperatures （PT） for 28 major weather stations in South Korea during the past 22 years （1983-2004） was investigated by employing a human heat budget model, the Klima-Michel model. The frequencies of a cold stress and a heat load by each region were compared. The sensitivity of PT in terms of the input of synoptic meteorological variables were successfully tested. Seogwipo in Jeju Island appears to be the most comfortable city in Korea. Busan also shows a high frequency in the comfortable PT range. The frequency of the thermal comfort in Seoul is similar to that of Daejeon with a relatively low frequency. In this study, inland cities like Daegu and Daejeon had very hot thermal sensations. Low frequencies of hot thermal sensations appeared in coastal cities （e.g., Busan, Incheon, and Seogwipo）. Most of the 28 stations in Korea exhibited a comfort thermal sensation over 40% in its frequency, except for the mountainous regions. The frequency of a heat load is more frequent than that of a cold stress. There are no cities with very cold thermal sensations. In this study, we found the decreasing trend of mortality with an increasing PT. If the PT is over any critical temperature point, however, the mortality rate increases again. The mortality variation with the PT of a station seems to be associated with the latitudinal location of the station, implying that it results from a regional acclimation effect of inhabitants.

关键词： Klima-Michel model perceived temperature thermal comfort

First discovery of a cave-dwelling Tineid moth(Lepidoptera, Tineidae) from East Asia

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Journal of Forestry Research 2014年第3期25卷 647-651页

作者： Bong-kyu Byun Sat-Byul Shin Yang-Seop Bae Do Sung Kim Yong Geun choi Department of Biological Science and Biotechnology Hannam University Division of Life Sciences University of Incheon The Institute for Conservation of Wild Species

In this study, we report Monopis crocicapitella （Clemens, 1859）（Tineidae）, which was collected from bat guano in a cave in the southern region of Korea, for the first time from East Asia. We briefly redescribe and illustrate the external morphology and genital structures of both sexes. Also, we discuss the local habitat characteristics and some of the ecological information that was observed during our field investi-gation.

关键词： Monopis Tineidae Lepidoptera Bat guano new record,Korea East Asia.