NHCF 막전극의 제조방법 및 운전조건에 따른 순환전위곡선의 특성 변화

이미경,한영,박승만,한정규,이상호,곽철,박인수,황영기 慶南大學校 附設 工業技術硏究所 1999 硏究論文集 Vol.17 No.-

본 연구는 이온교환 막전극을 이용하여 원자력 액상 폐기물로부터 방사성 성분을 분리하고 저장용 액상에 연속적으로 농축함으로써 폐기물의 잔류농도 저하와 최종 저장품의 부피감소를 동시에 도모하기 위한 목적의 일환으로 수행되었다. 화학적 및 전기적 방법으로 nickel hexacyanoferrate(NHCF)??막을 전도성 니켈표면에 생성시켜 막전극을 제조하였다. 각각의 막전극을 세슘과 나트륨의 단일 및 이성분 수용액에 설치하고 -100mV부터 800mV까지 50mV/s, 70mV/s, 100mV/s 그리고 150mV/s등의 주사속도로 전위순환을 연속적으로 반복하면서 순환전위곡선을 측정하였다. 이 과정에서 막전극의 제조방법, 주사속도, 세슘의 농도 등의 변화에 따른 순환전위곡선의 특성 변화를 비교 고찰하였다. 화학적 방법으로 48시간 이상 자연생성시켜야 이온교환 성능을 가지며, 생성 소요시간과 주사속도가 클수륵 반응성이 크고, 세슘 농도가 20% 이상인 이성분 용액에서는 NHCF 막전극이 세슘과 선택적으로 환원-산화 반응함을 알 수 있었다. This research has been carried out for the objective which was planned to decrease the residual concentration of nuclide in liquid wastes by separating the radioactive elements on ion exchange film electrode and to reduce the final storing volume by concentrating the deposited elements into small amount of wastewater. NHCF was prepared on the surface of conductive nickel by chemical and electrochemical methods. It was used as working electrode in cesium sodium, and binary aqueous solutions. We measured the cyclic voltammogram using the repeated cyclic voltammetry from -100mV to 800mV at the sweep rate of 50mV/s, 70mV/s, 100mV/s and 150mV/s. The transformation of cyclic voltammogram was investigated at the various NHCF film electrodes with the variation of sweep rate and concentration of cesium. The ion exchange was observed when NHCF was self-assembled chemically over 48 hours. The reactivity of NHCF increased with increasing preparation time and sweep rate. NHCF film electrode had redox reaction with cesium selectively in the binary solution when cesium concentration was more than 20%.

자폐장애와 어머니의 우울정도와 그들 자녀의 자폐증상간의 상관관계

이수경,곽영숙,강경미 대한소아ㆍ청소년정신의학회 1998 소아청소년정신의학 Vol.9 No.2

전기적으로 유도된 니켈핵사시아노페레이트 막전극의 이온교환 특성 : 전위순환법에 의한 NHCF 막전극과 중금속 양이온과의 이온 교환 특성 조사 Cyclic Voltammetric Investigation on the Characteristics of the Ion Exchange between NHCF Film Electrode and Heavy Metal Cations

이미경,한정규,곽철,황영기 경남대학교 신소재연구소 1999 論文集 Vol.11 No.-

본 연구에서는 NHCF 막전극과 중금속 양이온과의 이온교환 특성을 조사하기 위해, 먼저 니켈금속 표면에 페로시안 막을 전기적으로 생성시켜 NHCF 막전극을 제조하고, 순수한 니켈금속과 NHCF 막전극을 다양한 중금속 용액에 양극으로 각각 설치하여 순환전위곡선을 측정하였다. -100 mV에서 800 mV까지 10~1,500회 사이클을 연속적으로 반복한 순환전위곡선으로부터 각 중금속의 양이온에 대응하는 산화 및 환원반응의 첨두전류와 첨두전위의 변화 거동을 분석하였다. 또한 전위순환을 종료한 NHCF 막전극의 표면을 EDS로 분석하여 원자 구성비를 조사하였다. 크롬과 아연 용액에서 NHCF 막전극이 갖는 순환전위곡선의 첨두전류는 순환 회수에 따라 급속히 감소하는 반면에, 코발트, 카드뮴, 망간 용액에서는 환원 및 산화 전류가 서서히 감소한다. 코발트와 카드뮴은 막전극에 침적되는 양이 적은 반면에 망간은 많은 것으로 분석되었다. 또한 이온교환 막전극의 성능 감소는 일반 유기물 이온교환체의 평균 성능 감소율인 3%/사이클보다 훨씬 낮은 0.52~0.6%/사이클로 측정되었다. NHCF 막전극을 이용한 전기화확적 이온교환법으로 구리와 철을 분리할 수 없지만 크롬, 아연, 코발트, 망간 등의 분리 및 회수는 가능함을 알 수 있었다. For the investigation of the ion ex- change between NHCF film electrode and heavy metal cation, we have electrically deposited the ferrocyanide film on nickel surface and measured the cyclic voltammograms of both the pure nickel and the NHCF film electrode in various heavy metal aqueous solutions. Cyclic voltammetry was repeated from -100 mV to 800 mV versus SCE for 10 to 1,500 cycles. Peak current density and potential corresponding to the redox reaction in each solution were obtained from the measured cyclic voltammograms. By using EDS we also analyzed the atomic composition of the NHCF film electrode after the 1500th potential cycling. While the peak current density decreased spontaneously with the number of potential cycling in chromium and zinc solutions, it decreased slowly in cobalt, cadmium, and manganese solutions. The deposited amount of manganese on the NHCF electrode was bigger than that of cobalt and cadmium. The capacity loss of the KHCF ion exchanger was 0.52-0.6%/ cycle much smaller than the average loss of 3%/cycle of the conventional organic ion exchanger. It was found that electrically derivatized NHCF film was available to the electrochemical ion exchange for the separation and recovery of chromium, zinc, cobalt, cadmium, and manganese from wastewater, but not for copper and iron.

자폐아동에서 FMR-1 유전자에 대한 분자유전학적 연구

강경미,곽동일,이민수 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.6

연구목적: 자폐장애가 유전성이 있다고 제시하는 많은 쌍생아 및 가족연구와 유전자 연구에도 불구하고 이 질환의 유전방식과 관련 유전자는 현재까지 알려져 있지 않고, 이 장애는 임상적으로 이질적 장애이며 유전방식과 관련 유전자는 현재까지 알려져 있지 않고, 이 장애는 임상적 이질적 장애이며 유전적으로도 다인자 질환일 가능성이 높은 것으로 생각된다. 본 연구에서는 자폐장애와 FMR-1 유전자간의 연관성을 조사하고자 자폐장애 아동 총 66명을 대상으로 분자유전학적 검사를 시행하였다. 방 법: 연구대상군은 DSM-Ⅳ 진단기준으로 자폐장애가 해당하고 K-CARS 점수가 30점 이상인 아동들을 대상으로 하였다. Genomic DNA를 전혈에서 추출한후, 탐침 Xho/PstⅠ과 두 개의 제한효소(EcoR Ⅰ, Eag Ⅰ)를 사용하여 썼던 블롯팅을 시행하였다. 결 과: 연구대상 총 66명중 1명의 남아가 메칠화된 모자이크의 양상을 보이었고, 3명의 남아와 2명의 여아는 불완전 변이 양상을 보이었으나 완전 변이의 양상은 없었다. 결 론: 본 연구에서는 FMR-1 유전자가 자폐장애의 유전적 요인과 관련이 있다는 이전의 보고를 뒷받침할만한 명백한 결과를 얻지 못하였다. Objectives: To elucidate an association of the fragile X syndrome with autism, Southern blot analysis was performed in 66 autistic children aged from 2 years to 11 years. Methods: Subjects were 66 autistic children with of autistic disorder diagnosed by DSM-Ⅳ criteria and Childhood Autism Rating Scale-Korean version. Genomic DNA was extracted from peripheral blood and DNA was used to detect a FMR(Fragile Mental Retardation)-1 gene. Xho/PstI probes and two restriction enzymes(EcoRI, EagI)were used for Southern blot analysis. Results: There were one boy with a methylated mosaic pattern and 3 boys and 2 girls with an unmethylated premutation band. But there was no full mutation pattern. Conclusion: Although the possibility of the relationship between autistic disorder and FMR-1 gene has been suggested, the results from this study do not provide any definite association of FMR-1 gene with autism in autistic children.

지혈제 오염이 콤포머의 전단결합강도에 미치는 영향

허정무,곽주석,이황,이수종,임미경 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.2

One of this latest concepts in bonding are "total etch", in which both enamel and dentin are etched with an acid to remove the smear layers, and "wet dentin" in which the dentin is not dry but left moist before application of the bonding primer. Ideally, the application of a bonding agent to tooth structure should be insensitive to minor contamination from oral fluids. Clinically, contaminations such as saliva, gingival fluid, blood and handpiece lubricant are often encountered by dentists during cavity preparation. The aim of this study was to evaluate the effect of contamination by hemostatic agents on shear bond strength of compomer restorations. One hundred and ten extracted human maxillary and mandibular molar teeth were collected. The teeth were removed soft tissue remnant and debris and stored in physiologic solution until they were used. Small flat area on dentin of the buccal surface were wet ground serially with 400, 800 and 1200 abrasive papers on automatic polishing machine. The teeth were randomly divided into 11 groups. Each group was conditioned as follows: Group 1: Dentin surface was not etched and not contaminated by hemostatic agents. Group 2: Dentin surface was not etched but was contaminated by Astringedent® (Ultradent product Inc., Utah, U.S.A.). Group 3: Dentin surface was not etched but was contaminated by Bosmin®(Jeil Pharm, Korea).). Group 4: Dentin surface was not etched but was contaminated by Epri-dent®(Epr Industries, NJ, U.S.A.). Group 5: Dentin surface was etched and not contaminated by hemostatic agents. Group 6: Dentin surface was etched had contaminated by Astringedent®. Group 7: Dentin surface was etched and contaminated by Bosmin®. Group 8: Dentin surface was etched and contaminated by Epri-dent®. Group 9: Dentin surface was contaminated by Astringedent®. The contaminated surface was rinsed by water and dried by compressed air. Group 10: Dentin surface was contaminated by Bosmin®. The contaminated surface was rinsed by water and dried by compressed air. Group 11: Dentin surface was contaminated by Epri-dent®. The contaminated surface was rinsed by water and dried by compressed air. After surface conditioning. F2000® was applicated on the conditoned dentin surface. The teeth thermocycled in distilled water at 5℃ and 55℃ for 1,000 cycles. The samples were placed on the binder with the bonded compomer-dentin interface paralled to the knife-edge shearing rod of the Universal Testing Machine(Zwick Z020, Zwick Co., Germany) running at a cross head speed of 1.0mm/min. Group 2 showed significant decrease in shear bond strength compared with group 1 and group 6 showed significant decrease in shear bond strength compared with group 5. There were no significant differences in shear bond strength between group 5 and group 9, 10 and 11.

감염근관에서 Black-Pigmented Bacteria의 동정에 대한 연구

권은경,김은숙,곽주석,이황,이수종,임미경 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.1

Black-pigmented bacteria have been implicated in the endodontic infections. This group of microorganisms includes Porphyromonass endodontalis, Porphyromonas gingicalis, Prevotella intermedia, and Prevotella nigresceus. The organisms display a wide variety of virulence factors that may be pertinent to acute endodontic infections. The aim of this study was to identify P.endodontalis, P.gingivalis, P.intermedia, and P.nigrescens by using special potency disk test, filter paper spot test, 16S rRNA gene-directed PCR, and API 32A. Microbial samples were collected from root canals of 33 intact teeth with necrotic pulp and/or apical periodontitis. Conventional laboratory methods were used for identification of the strains of black pigmented bacteria. Eighteen of 33 samples were positive for the growth of black-pigmented bacteria. Five colonies were cultured from each pure cultured colonies from Brucella agar plate. Seventy seven colonies were positive for the growth of black-pigmented bacteria. Thirty three of 77(42.6%) were identifed as P.nigrescens, 10 of 77(12.9%) were P.gingivalis, 6 of 77(7.8%) were P.endodontalis, 10 of 77(12.9%) were P.intermedia. On the contraty the reference strains of P.nigrescens, experimental strains of P.nigrescens was sensitive to kanamycin in special potency disk test. 16S rRNA gene PCR and API test after rapid presumptative identification methods. such as special potency disk test and filter paper spot test, would be accurate detection methods for black-pigmented bacteria.

Current Perspectives regarding Stem Cell-Based Therapy for Alzheimer's Disease

Kwak, Kyeong-Ah,Lee, Seung-Pyo,Yang, Jin-Young,Park, Young-Seok Hindawi 2018 Stem cells international Vol.2018 No.-

<P>Alzheimer's disease (AD), a progressive neurodegenerative disorder featuring memory loss and cognitive impairment, is caused by synaptic failure and the excessive accumulation of misfolded proteins. Many unsuccessful attempts have been made to develop new small molecules or antibodies to intervene in the disease's pathogenesis. Stem cell-based therapies cast a new hope for AD treatment as a replacement or regeneration strategy. The results from recent preclinical studies regarding stem cell-based therapies are promising. Human clinical trials are now underway. However, a number of questions remain to be answered prior to safe and effective clinical translation. This review explores the pathophysiology of AD and summarizes the relevant stem cell research according to cell type. We also briefly summarize related clinical trials. Finally, future perspectives are discussed with regard to their clinical applications.</P>

Development and Roll-Out of A Coronavirus Disease 2019 Clinical Pathway for Standardized Qualified Care in Public Hospitals in Korea

Kwak Mi Young,Jo Eun Young,Chin Bum Sik,Park Se Eun,Yim Jun,Lee Jung Eun,Jo Kyung Eun,Kim Yeon-Sook,Lee Jeong Eun,Yoon Young Kyung,Seo Yu Bin,Jeong Su Jin,Kang Yu Min,Joo Eun-Jeong,Yoon Jong Hyun,Kim 대한감염학회 2022 Infection and Chemotherapy Vol.54 No.2

Despite the coronavirus disease 2019 (COVID-19) vaccination roll-out, variant-related outbreaks have occurred repeatedly in Korea. Although public hospitals played a major role in COVID-19 patients’ care, difficulty incorporating evolving COVID-19 treatment guidelines called for a clinical pathway (CP). Eighteen public hospitals volunteered, and a professional review board was created. CPs were formulated containing inclusion/exclusion criteria, application flow charts, and standardized order sets. After CP roll-out, key parameters improved, such as increased patient/staff five-point satisfaction scores (0.41/0.57) and decreased hospital stays (1.78 days)/medical expenses (17.5%). The CPs were updated consistently after roll-out as new therapeutics drugs were introduced and quarantine policies changed.

Relationship between psychological wellbeing of social welfare facility workers and their organizational commitment

Mi-Kyung Kwak,Sung-Je Cho 한국정보전자통신기술학회 2018 한국정보전자통신기술학회논문지 Vol.11 No.6

The purpose of this study is to identify the relationship between psychological wellbeing of social welfare facility workers and their organizational commitment. The subjects of this study were 230 social welfare facility workers in OO city, Gyeongsangbuk-do, Korea. Analysis was conducted using the SPSS program, including frequency analysis, reliability analysis and correlation analysis, and regression analysis on the causal relationship between variables. The results of the study showed that the psychological wellbeing of social welfare facility workers had a meaningful effect on their emotional commitment, continuous commitment and normative commitment. These results confirmed that the higher the psychological wellbeing of social welfare facility workers, the higher the sub-factors of organizational commitment, such as emotional, continuous, normative commitment, resulting in positive effects on the achievement of goals and values that are pursued by the welfare facilities. This study aims to become foundational data for the improvement of working conditions to improve psychological wellbeing of social welfare facility workers to increase organizational commitment.

Galangin enhances TGF-β1-mediated growth inhibition by suppressing phosphorylation of threonine 179 residue in Smad3 linker region

Kwak, Mi-Kyung,Yang, Kyung-Min,Park, Jinah,Lee, Siyoung,Park, Yuna,Hong, Eunji,Sun, Eun Jin,An, Haein,Park, Sujin,Pang, Kyoungwha,Lee, Jihee,Kang, Jin Muk,Kim, Pyunggang,Ooshima, Akira,Kim, Seong-Jin Elsevier 2017 Biochemical and biophysical research communication Vol. No.

<P><B>Abstract</B></P> <P>Smad3 linker phosphorylation is a candidate target for several kinases that play important roles in cancer cell initiation, proliferation and progression. Also, Smad3 is an essential intracellular mediator of TGF-β1-induced transcriptional responses during carcinogenesis. Therefore, it is highly advantageous to identify and develop inhibitors targeting Smad3 linker phosphorylation for the treatment of cancers. Galangin (3,5,7-trihydroxyflavone) has been known to be an active flavonoid showing a cytotoxic effect on several cancer cells. However, the mechanism of action of galangin in various cancers remains unclear, and there has been no report concerning regulation of Smad3 phosphorylation by galangin. In the present study, we show that galangin significantly induced apoptosis and inhibited cell proliferation in the presence of TGF-β1 in both human prostate and pancreatic cancer cell lines. Particularly, galangin effectively inhibits phosphorylation of the Thr-179 site at Smad3 linker region through suppression of CDK4 phosphorylation. Thus, galangin can be a promising candidate as a selective inhibitor to suppress phosphorylation of Smad3 linker region.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Galangin significantly induced apoptosis in the presence of TGF-β1. </LI> <LI> Galangin inhibits phosphorylation of the Thr-179 site at the Smad3 linker region. </LI> <LI> Galangin suppresses CDK4-mediated Smad3 linker phosphorylation. </LI> </UL> </P>