4,4′-Biphenyldicarboxylate sodium coordination compounds as anodes for Na-ion batteries

Choi, Aram,Kim, Yun Kyeong,Kim, Tae Kyung,Kwon, Mi-Sook,Lee, Kyu Tae,Moon, Hoi Ri The Royal Society of Chemistry 2014 Journal of Materials Chemistry A Vol.2 No.36

<P>Novel 4,4′-biphenyldicarboxylate (bpdc) sodium salts with different compositions were evaluated for the first time as anodes for Na-ion batteries, and their crystal structures and corresponding electrochemical performances were analyzed. The structure of the bpdc-sodium salts was modified using precipitation and solvothermal methods to afford three different crystal structures with different degrees of deprotonation of the carboxylic acid (COOH) groups and different coordination of the water molecule, as determined by single crystal X-ray diffraction. The extent of deprotonation in bpdc-sodium salts not only affects their electrochemical performance, but also affects the corresponding reaction mechanisms. The fully deprotonated bpdc-disodium salt exhibits a promising electrochemical performance with a reversible capacity of about 200 mA h g<SUP>−1</SUP>at<I>ca.</I>0.5 V<I>vs.</I>Na/Na<SUP>+</SUP>, stable cycle performance over 150 cycles, and an excellent rate performance of 100 mA h g<SUP>−1</SUP>even at a 20 C rate, which are better than those of the partially deprotonated bpdc-sodium salt. The sodiation-desodiation of bpdc-sodium salts proceeds in a two-phase reaction, regardless of the degree of deprotonation. However, unlike the fully deprotonated bpdc-disodium salt, which shows a reversible phase transition during sodiation and desodiation, the partially deprotonated bpdc-sodium salt exhibits an irreversible phase transition during cycling.</P>

The Effectiveness of the Use of Regdanvimab in Addition to Remdesivir in Patients with Severe COVID-19: A Single Center Retrospective Study

( Aram Choi ),( Woon-jung Kwon ),( Soyeoun Lim ),( Hyeon Hui Kang ),( Jin Hyoung Kim ),( Byung Ju Kang ),( Yangjin Jegal ),( Jong Joon Ahn ),( Eun Ji Park ),( Jae-bum Jun ),( Taehoon Lee ) 대한결핵 및 호흡기학회 2021 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.129 No.0

Background Although the use of remdesivir and systemic corticosteroids has reduced the number of deaths due to coronavirus disease 2019 (COVID-19), this disease still has a high mortality rate when it is severe. Regdanvimab (CT-P59), a neutralizing monoclonal antibody that has been proven effective against mild COVID-19, may be effective against severe COVID-19. This study was conducted to determine the effectiveness of the combined use of remdesivir and regdanvimab in patients with severe COVID-19 Methods From March to early May 2021, 124 patients with severe COVID-19 were admitted to Ulsan University Hospital (Ulsan, Korea) and received oxygen therapy and remdesivir. Among them, 25 were also administered regdanvimab before remdesivir. We retrospectively compared the clinical outcomes between the remdesivir alone group [n = 99 (79.8%)] and the regdanvimab/ remdesivir group [n = 25 (20.2%)]. Results The oxygen-free days on day 28 (primary outcome), defined as the number of days a patient was alive and oxygen-free for 28 days from the beginning of remdesivir administration, were significantly higher in the regdanvimab/remdesivir group [mean ± SD (standard deviation): 19.36 ± 7.87 vs. 22.72 ± 3.66, P = 0.003]. The association between the regdanvimab/remdesivir group and oxygen-free days was also significant in the multivariate analysis (logistic regression), after adjusting for the initial SpO2/FiO2 ratio (severity index). Further, in the regdanvimab/remdesivir group, the lowest SpO2/FiO2 ratio during treatment was significantly higher (mean ± SD: 237.05 ± 89.68 vs. 295.63 ± 72.74, P = 0.003), and the Kaplan-Meier estimates of oxygen supplementation days in surviving patients (on day 28) were significantly shorter [mean ± SD: 8.24 ± 7.43 vs. 5.28 ± 3.66, P (logrank test) = 0.024] (Figure). Conclusions In patients with severe COVID-19, clinical outcomes can be improved by administering regdanvimab, in addition to remdesivir. This abstract was also submitted to APSR 2021.

Site-Selective In Situ Electrochemical Doping for Mn-Rich Layered Oxide Cathode Materials in Lithium-Ion Batteries

Choi, Aram,Lim, Jungwoo,Kim, Hyung-Jin,Jung, Sung Chul,Lim, Hyung-Woo,Kim, Hanseul,Kwon, Mi-Sook,Han, Young Kyu,Oh, Seung M.,Lee, Kyu Tae Wiley (John WileySons) 2018 ADVANCED ENERGY MATERIALS Vol.8 No.11

직장인의 대인관계능력에 대한 기질적, 심리적 요인과 상담적 접근

최아람 ( Aram Choi ),이지연 ( Jiyeon Lee ) 인천대학교 사회과학연구원 2017 사회과학연구 Vol.10 No.2

본 연구의 목적은 대인관계능력에 영향을 미치는 기질적, 심리적 요인을 검토하여 직장인의 대인관계능력 향상을 위한 개입 방향과 앞으로의 연구 방향을 모색하는데 있다. 대인관계능력에 영향을 미치는 기질적 요인으로 행동억제성향을 살펴보았는데, 행동억제성향이 대인관계에 영향을 준다는 연구는 많이 있지만, 어떤 변인을 통해 영향을 주고 있는지 그 과정에 대한 연구는 부족한 실정이다. 하여 대인관계능력에 영향을 줄 수 있는 심리적 요인들을 알아보고 그 중 행동억제성향의 영향과 직장인의 상황적 특성을 고려하여 사회불안과 정서인식 명확성을 그 요인으로 제시하였다. 즉, 행동억제성향이 사회불안과 정서인식 명확성에 영향을 주고, 이는 대인관계능력으로 연결될 수 있음을 선행연구들을 통해 확인하였다. 마지막으로 상담에서의 함의와 향후 연구 방향을 논의하였다. The purpose of this research is to investigate temperamental and psychological factors that affect interpersonal relationship skills, and to explore direction of intervention for improving interpersonal relationship skills at work and direction of subsequent research. In precedence research, it is known that behavior inhibition system affects interpersonal relationship skills, but there’s few researches dealing with a process about what variables are affecting. So this research examined psychological factors that can affect interpersonal relationship skills and suggested social anxiety and emotional clarity as the variables under consideration of behavior inhibition system and the situation characteristics of Employees. In other words, it is confirmed in precedence research that behavior inhibition system affects social anxiety and emotional clarity, so that affects interpersonal relationship skills. Finally, implications at psychological counseling and direction of subsequent research were discussed.

Evaluation of amine-functionalized acrylic ion exchange fiber for chromium(VI) removal using flow-through experiments modeling and real wastewater

Nam, Aram,Choi, Ung Su,Yun, Seong-Taek,Choi, Jae-Woo,Park, Jeong-Ann,Lee, Sang-Hyup THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.66 No.-

<P><B>Abstract</B></P> <P>Poly(acrylo-amidino diethylenediamine) (PADD), fibrous form of anion exchangers, was synthesized to remove Cr(VI). The experimental results were described well by the Langmuir isotherm model (Q<SUB>max</SUB> =4.67mmol/g) and pseudo second-order model. The Cr(VI) adsorption capacities were increased by decreasing pH because the –NH<SUB>2</SUB> in PADD become more positively charged. During five regeneration cycles, Cr(VI) adsorption capacity retained over 95.96% of the initial capacity. Color of the PADD (yellow) changed to green owing to Cr(VI) reduction to Cr(III) and amine transformed into a oxidized form (imine). The PADD was successfully treated Cr(VI) in two different concentrations of industrial wastewater.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PADD was successfully synthesized by chemical grafting of polyacrylonitrile fiber. </LI> <LI> Cr(VI) adsorption on PADD is rapid process with maximum capacity of 4.67mmol/g. </LI> <LI> High Cr(VI) adsorption capacity of PADD is maintained in flow-through condition. </LI> <LI> Cr(VI) adsorption capacity of PADD is retained during five regeneration steps. </LI> <LI> PADD can treat well with a real plating wastewater containing Cr(VI). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Position-selective metal oxide nano-structures using graphene catalyst for gas sensors

Lee, Aram,Park, Jinheon,Choi, Kyoung Soon,Lee, Jouhahn,Yoo, Ilhan,Cho, In Sun,Ahn, Byungmin,Seo, Hyungtak,Choi, Jae-Young,Yu, Hak Ki Elsevier 2017 Carbon Vol.125 No.-

<P>The thermal transport growth of various metal oxide (MOx) nanostructures using graphene as a catalytic layer was studied. Graphene was synthesized by Cu-catalyzed chemical vapor deposition and transferred onto a SiO2-covered Si substrate using bubble transfer methods. Due to the catalytic activity of the atomic-thick carbon layer, control of the position of the MOx nanostructures as well as the growth parameters, such as nucleation density and growth rate, could be achieved. The position-selective and density-controlled MOx nanostructures were evaluated for hydrogen gas sensor applications, where different responses were obtained with hydrogen molecules. (C) 2017 Elsevier Ltd. All rights reserved.</P>

아크릴계 이온교환섬유를 이용한 수중 크롬(VI) 제거

남아름(Aram Nam),박정안(Jeong-Ann Park),도태구(Taegu Do),최재우(Jae-Woo Choi),최웅수(Ungsu Choi),김경남(Kyung Nam Kim),윤성택(Seong-Taek Yun),이상협(Sanghyup Lee) 大韓環境工學會 2017 대한환경공학회지 Vol.39 No.3

PAN 기반 아크릴계 섬유와 DETA 및 AlCl3・6H2O를 반응시켜 아민기(-NH2)를 가진 이온교환섬유 PADD를 합성하였다. 개발된 섬유상 소재는 FT-IR과 SEM을 이용하여 그 특성을 확인해 보았다. 회분식 실험으로 수행된 PADD를 이용한 크롬제거 실험 결과는 Langmuir 등온흡착모델에 잘 적용되었으며, 이때 계산된 이론적 최대흡착능 (Qmax)은 6.93 mmol/g으로 나타났다. 한편 동적흡착실험은 Lagergren 유사이차속도모델에 잘 부합되었다. PADD의 크롬 흡착능은 pH 2에서 가장 높은 값인 4.11 mmol/g을 나타내었고 pH 변화에 많은 영향을 받는 것으로 확인되었다. 또한, 인산과 비소(V)에 대한 공존이온 실험을 통해 PADD가 크롬에 대한 높은 선택성을 갖고 있음을 확인할 수 있었다. 산-염기 역적정으로 구한 PADD의 총이온교환능 (4.70 mmol/g)을 통해 소재의 선택적 제거 가능성을 검증하였다. Ion exchange fiber, PADD was synthesized by the reaction between PAN based acrylic fiber and DETA with AlCl3・6H2O, and was analyzed by FT-IR and SEM to investigate its characteristics. The experimental results of Cr(VI) removal by PADD were better fitted with Langmuir adsorption isotherm, and the maximum uptake value (Qmax) was calculated to be 6.93 mmol/g. The kinetic data can be well described by Lagergen pseudo-second order rate model. The Cr(VI) adsorption capacity of PADD was 4.11 mmol/g at pH 2, which shows the effect of pH changes on the removal of Cr(VI). The adsorption selectivity of Cr(VI) was higher than phosphate and As(V). Total ion exchange capacity of PADD was 4.70 mmol/g, which was measured by acid-base back titration.

임신 여성 근로자의 제대혈 중 망간 농도 추정

이아람 ( Aram Lee ),최경호 ( Kyungho Choi ),김해중 ( Hai-Joong Kim ),이정재 ( Jeong Jae Lee ),최규연 ( Gyuyeon Choi ),김성주 ( Sungjoo Kim ),김수영 ( Su Young Kim ),조금준 ( Geumjoon Cho ),김영돈 ( Youg Don Kim ),서은숙 ( Eunsook 한국산업보건학회 2018 한국산업보건학회지 Vol.28 No.3

Objectives: This study aims to analyze manganese (Mn) concentrations in maternal and cord bloods at delivery and to estimate the Mn exposure risk for fetuses whose mothers were occupationally exposed to Mn. Materials and Methods: Forty-six pairs of maternal and cord blood samples were collected at delivery from mothers who were occupationally unexposed to Mn. Mn concentrations of blood were analyzed by graphite furnace atomic absorption spectrometer. Mn exposure levels for fetuses of female workers were estimated by simulating two working exposure scenarios. Results: The geometric mean concentration of Mn in maternal and cord blood were 27.0(1.34) ㎍/L, 46.6(1.25) ㎍/L, respectively. Transfer ratios of Mn from maternal to cord blood were 1.81±0.62, which indicated that the Mn concentrations in cord blood were higher than those in maternal blood. Mn concentrations in cord blood for the worse or general scenarios were estimated to 22.3-1,881 ㎍/L and 1.59-308 ㎍/L, respectively. The probabilities of exceeding 74 ㎍/L, which was adopted as a reference level reported in a previous study, were 95% and 44% for the two scenarios, respectively. Conclusions: Comparable levels of Mn exposure in maternal or cord blood to those in this study have shown various health effects in previous studies. This suggests that Mn exposure levels in mothers and fetuese in Korea need to be monitored and managed. In addition, female workers who are occupationally exposed to Mn should be protected from the exposure since their fetuses can be exposed to Mn at risky levels during their pregnancy.

메시 세분화가 햅틱 충돌 탐지 알고리즘에 미치는 영향

최아람(Aram Choi),김지범(Jibum Kim),성미영(Meeyoung Sung) 한국정보과학회 2015 한국정보과학회 학술발표논문집 Vol.2015 No.6

Association of urinary phthalate metabolites and phenolics with adipokines and insulin resistance related markers among women of reproductive age

Lee, Inae,Kim, Sunmi,Park, Suhyeon,Mok, Sori,Jeong, Yunsun,Moon, Hyo-Bang,Lee, Jangwoo,Kim, Sungkyoon,Kim, Hai-Joong,Choi, Gyuyeon,Choi, Sooran,Kim, Su Young,Lee, Aram,Park, Jeongim,Choi, Kyungho Elsevier BV 2019 Science of the Total Environment Vol.688 No.-

<P><B>Abstract</B></P> <P>Chemicals such as phthalates and phenolics have been associated with metabolic markers in humans. However, most studies have only looked at a limited number of chemicals, and little is known about their potential effects on adipokines in humans. In the present study, the associations between dozens of urinary chemicals, including phthalate metabolites and phenolics, and markers related to insulin resistance as well as major adipokines, were assessed among the women of reproductive age (<I>n</I> = 459, between 20 and 48 years of age) recruited from major cities in Korea between 2015 and 2016. Adipokines such as adiponectin and leptin, and insulin resistance related markers such as glucose and insulin, were analyzed in serum. Associations between urinary chemicals and the adipokines or insulin resistance related markers were assessed in two steps. First, ordinary least squares (OLS) regression was used to assess the association of each urinary chemical with the adipokines or insulin resistance related markers (single-pollutant model). Second, several chemicals were selected using elastic net regression and were subsequently analyzed with OLS regression model (multi-pollutant model), considering simultaneous exposure to multiple chemicals. In both single- and multi-pollutant models, several urinary chemicals consistently showed significant associations with adipokines or the insulin resistance related markers. The sum of di-(2-ethylhexyl) phthalate metabolites (ΣDEHPm) and ethyl paraben (EtP) were associated with increased serum adiponectin levels. Urinary ΣDEHPm levels also showed positive associations with fasting glucose. Moreover, urinary mono-methyl phthalate (MMP), mono-isobutyl phthalate (MiBP), and bisphenol S (BPS) levels showed positive associations with the homeostasis model assessment for insulin resistance (HOMA-IR). Interestingly, urinary propyl paraben (PrP) levels showed a negative association with HOMA-IR, in both models. Our observations show that among many consumer chemicals, phthalates may affect serum adipokines, and thus glucose, and insulin resistance in adult females. Further confirmation is warranted in other populations.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Urinary chemicals and metabolism related markers were measured in women of reproductive age. </LI> <LI> Multiple chemicals were considered in statistical models for adipokines and insulin resistance. </LI> <LI> Sum of DEHP metabolites and EtP were positively associated with serum adiponectin levels. </LI> <LI> Sum of DEHP metabolites was significantly associated with increased fasting glucose. </LI> <LI> MiBP was significantly associated with for increased HOMA-IR. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>