Effects of kojic acid, arbutin and vitamin C on cell viability and melanin synthesis in B16BL6 cells

( Yumi Park ),( Jongsung Lee ),( Junho Park ),( Deokhoon Park ) 대한화장품학회 2003 대한화장품학회지 Vol.29 No.1

Melanin biosynthesis is a human defense mechanism to protect skin from UV irradiation and also determines colors of hair and skin. However, as a interest on skin-whitening increases, researches to prevent pigmentation and hypersynthesis of melanin in skin are being actively in progress. Active components used as a whitening agent in cosmeceuticals are kojic acid, arbutin, vitamin C and hydroquinone. However, until now, because comparison researches among them in the aspect of both melanin formation and cellular toxicity have not been performed, we can't exactly estimate merits and defects of them as a whitening agent. To this end, we performed experiments to compare their effects on cell viability and melanin formation. As a first step, in vitro tyrosinase inhibition assay was done. While kojic acid and hydroquinone showed strong inhibition activities(their IC₅₀/s are all < 100uM), arbutin and vitamin C showed weak activities. IC₅₀/s of arbutin and vitamin C are 100uM and 400∼500uM, respectively. In B16BL6 melanoma cells, like in vitro tyrosinase inhibition assay, arbutin and kojic acid showed more strong inhibition effect on melanin synthesis than vitamin C. And unlike arbutin, vitamin C and kojic acid induced cell death at high concentration. Although arbutin showed no cytotoxicity, it has side effect to induce morphological change at high concentration.. In this paper, we suggest both kojic acid and arbutin have stronger ability to inhibit melanogenesis than vitamin C. And they also have side effect, that is, kojic acid induces cell death like vitamin C and arbutin changes cell morphology respectively.

Fortune or Misfortune? An Isoniazid Resistant Strain Evade Screening Both of Phenotypic DST and Genotypic DST

( Yumi Park ),( Sung Young Lee ),( Young-kyung Choi ),( Yong-soon Cho ),( Tae Won Jang ),( Je Hun Kim ),( Jee Youn Oh ),( Jaehee Lee ),( Hyewon Seo ),( Jae-gook Shin ) 대한결핵 및 호흡기학회 2020 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.128 No.-

Background Discordancy across phenotypic (pDST) and genotypic drug susceptibility test (gDST) Results of isoniazid (INH) and rifampicin (RIF) has been reported between 5%-15%, depending on the compared Methods. The strain has been considered as resistant to test drugs, either one is shown as resistant. However, the strain would be considered as drug-susceptible (DS) if it was the false-negative in both pgDST. Here we report five discrepancy cases and one case of false-negative INH resistant strain screened by the MIC test. Method Results of pDST, gDST, and minimum inhibitory concentration (MIC) of 108 cPMTb clinical Mycobacterium tuberculosis (Mtb) isolates were compared. DNA sequences of resistant genes were analyzed by Sanger sequencing for discrepant cases. Anti-tuberculosis (TB) drug concentrations and N-acetyltransferase-2 (NAT2) genotypes of patients were analyzed to estimate the effectiveness of anti-TB drugs based on the pharmacokinetic model. Result Six cases (5.6%) of discrepancy were found among 108 cPMTb MIC tested Mtb isolates. Four of gRpS strains were confirmed as rifampicin or isoniazid low-level resistance. The other two (gS)pS strains were confirmed as low-level resistance of ethambutol or isoniazid. The INH gSpS strain was redefined as an INH-resistance via MIC and DNA sequencing. It harbored a rare mutation Q439R in katG. Despite the INH resistance, the patient was exposed to sufficient INH concentration according to our pharmacokinetic simulation. Conclusion The MIC tests screened one-third of discrepancy cases in this study. Currently, the MIC test is not conducted regularly for first-line anti-TB drugs. The discrepancy rate would be increased if the MIC test and DNA sequencing are widely undertaken.

MIC Distribution of Isoniazid, Rifampicin, Ethambutol, Pyrazinamide, and Levofloxacin in cPMTb Cohort Mycobacterium Tuberculosis Isolates

( Yumi Park ),( Sun-young Lee ),( Eun-soon Son ),( Jeong Seong Yang ),( Jake Whang ),( Tae Won Jang ),( Je Hun Kim ),( Jee Youn Oh ),( Hyn Kuk Kim ),( Hyo-jung Kim ),( Yong-soon Cho ),( Jae-gook Shin 대한결핵 및 호흡기학회 2020 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.128 No.-

Background Minimum inhibitory concentration (MIC) of antibiotics has been widely conducted for drug susceptibility tests (DST) of most bacterial infectious diseases, except tuberculosis (TB). Current phenotypic DST for TB uses one or two critical concentrations to determine the resistance of anti-TB drugs. The MIC test would be necessary not only for therapeutic drug monitoring-based precision medicine but also for detecting borderline resistance of anti-TB drugs. Here, we present the distribution of MIC of 4 first-line drugs and levofloxacin in cPMTb cohort Mycobacterium tuberculosis (Mtb) isolates. Methods From 2019-2020, 108 Mtb strains were collected in the cPMTb cohort. Broth microdilution Method in 96 well plates was used for the MIC test of anti-TB drugs, except for pyrazinamide (PZA). MGIT960 system was used for PZA MIC determination. Results The proportions of drug-resistant (DR) and drug-susceptible (DS) strains were 15.7% and 84.3%, respectively. Most of the DS MIC were distributed below the critical concentration of the drug. Three discordances between phenotypic DST and MIC were found in isoniazid, which is 2.8% in total. We observed 2 cases (1.9%) of low-level resistance (MIC 0.5 ug/ml), determined as DS for rifampicin in phenotypic DST but DR in genotypic DST. Conclusion MIC of cPMTb cohort 108 strains were distributed mostly below the critical concentration of all drugs. There are 6 cases of discordance between MIC and DST (phenotypic or genotypic). The MIC test could be utilized to overcome the limitation of phenotypic DST using critical concentration and fill the gap between genotypic and phenotypic DST.

MIC Distribution of Anti-tuberculosis Drugs in cPMTb Cohort Mycobacterium Tuberculosis Clinical Isolates

( Yumi Park ),( Jae-gook Shin ),( Sun-young Lee ),( Jeong Seong Yang ),( Jake Whang ),( Eun-soon Son ),( Tae Won Jang ),( Je Hun Kim ),( Jee Youn Oh ),( Jusang Kim ),( Hyungwoo Kim ),( Yong-soon Cho ) 대한결핵 및 호흡기학회 2021 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.129 No.0

Background Minimum inhibitory concentration (MIC) of antibiotics has been widely conducted for drug susceptibility test (DST) of most bacterial infectious diseases, except tuberculosis (TB). Current phenotypic DST for TB uses one or two critical concentrations to determine the resistance of anti-TB drugs. The MIC test would be necessary not only for therapeutic drug monitoring-based precision medicine but also for detecting borderline resistance of anti-TB drugs. Here, we present the distribution of MIC of anti-TB drugs in cPMTb cohort Mycobacterium tuberculosis (Mtb) isolates. Methods From 2019-2020, 205 Mtb strains were collected in the cPMTb cohort. Broth microdilution method in 96 well plates were used for the MIC test of anti-TB drugs, except for pyrazinamide (PZA). MGIT960 system was used for PZA MIC determination. Results The proportions of drug-resistant (DR) and drug-susceptible (DS) strains were 13.1% and 86.9%, respectively. Most of the DS MIC were distributed below the critical concentration of the drug. Six discordances between phenotypic or genotypic DST and MIC were found in this study. Two cases of disputed mutation L511P on rpoB were included in the discordance cases. Their MIC of rifampicin was 0.5 ug/ml. It is lower than critical concentration but higher than epidemiological cut-off value. Conclusion MIC of cPMTb cohort 205 strains were distributed mostly below the critical concentration of all drugs. There are 6 cases of discordance between MIC and DST (phenotypic or genotypic). The MIC test could be utilized to overcome the limitation of phenotypic DST using critical concentration and fill the gap between genotypic and phenotypic DST.

Mechanistic Insights into Thermal Stability Improvement of <i>exo</i>-Tetrahydrodicyclopentadiene by a New Hydrogen Donor: 5,6,7,8-Tetrafluoro-1,2,3,4-tetrahydroquinoxaline

Park, Sun Hee,Park, Yumi,Han, Jeong Sik,Jeong, Byung Hun,Han, Hogyu,Kim, Sung Hyun American Chemical Society 2015 ENERGY AND FUELS Vol.29 No.1

<P>We investigated the thermal stability of <I>exo</I>-tetrahydrodicyclopentadiene (<I>exo</I>-THDCP, C<SUB>10</SUB>H<SUB>16</SUB>) in the absence and presence of 5,6,7,8-tetrafluoro-1,2,3,4-tetrahydroquinoxaline (TFQox), a new hydrogen donor (H donor). Conversion of <I>exo</I>-THDCP was slowed in the presence of TFQox but less effectively compared to its analogues, 1,2,3,4-tetrahydroquinoxaline (THQox) and 1,2,3,4-tetrahydroquinoline (THQ). We analyzed the H-donor effects on the thermal decomposition kinetics of <I>exo</I>-THDCP, which explains the relative effect of the H donors on the thermal stability improvement of <I>exo</I>-THDCP.</P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ef5016445'>ACS Electronic Supporting Info</A></P>

Validation of an Analytical Method to Quantify Acrylamide in Foods by LC-MS/MS

Yumi Park,Su Yeon Lee,Cheong-Tae Kim,Seong Jin Park 한국식품영양과학회 2018 한국식품영양과학회 학술대회발표집 Vol.2018 No.10

Policies and Corporate Responses to the Plastic Pollution Crisis

Park Yumi 산업연구원 2022 KIET Industrial Economic Review Vol.27 No.3

근현대 서울의 법령과 근대의 일상성 -수도 법령으로 나타난 경성의 일상 변화를 중심으로-

박유미(Park, Yumi) 서울민속학회 2018 서울민속학 Vol.- No.5

1980년에 생겨난 수돗물은 이후 여러 법령을 통해 경성 사람들에게 제공되었다. 이로써 물을 함부로 사용하거나, 오염시키는 행위는 불법이 되었다. 물을 보호하고 시설을 설치하며, 분배하여 쓸 수 있게 하는 것은 오로지 행정기관뿐이었다. 전통적인 물과 관련된 크고 작은 전통적 의식이나 행동들도 수원 보호를 어렵게 만드는 행위로 간주되었다. 이러한 수돗물이 등장하기 전부터 물을 필요로 하는 사람들에게 물을 판매한 물장수들은 근대적 수도가 설치된 후로도 이를 활용한 급수영업을 계속하였다. 식민지권력은 수돗물을 사용하는 물장수들의 영업을 막으려 노력하였지만 경성 내의 수도 설치 미비와 민족적 갈등이라는 실질적이고도 첨예한 성격의 문제로 완전히 제압하기란 어려웠을 것이다. 더욱이 물장수들의 영업권 보장 요구는 생존권이라는 문제뿐만 아니라 사회 무산층의 교육권 보장이라는 내용까지 결부되어 있었기 때문에 더욱 그러했으리라 생각된다. 한편, 수돗물과 수도 관련 법령 및 규율 등을 적극적으로 수용한 계기는 위생의 측면 때문이었다. 위생의 담론은 그간 일본인들에 의해 조선인들을 ‘불결’하게 만드는 개념이었으나 1920년대 콜레라의 유행 이후에는 사람들의 생명을 지키는 근대적이고 과학적인 개념이 되었다. 그래서 경성의 사람들은 적극적으로 위생 담론을 체득하였고 이를 실천하였다. 실천의 일환으로 수돗물의 이용도 이전보다 증가하였다. 이런 수돗물을 활용한 여러 상점이 경성의 거리에 자리잡았다. 요리점, 이발소, 목욕탕, 세탁소, 카페, 빙수집 등은 경성의 번화가를 만들었으며, 경성 사람들의 생활을 좀 더 도시화되도록 이끌었을 것이다. 물론 이러한 것은 수도가 설치된 곳에서만 사용가능하지만 생활의 편리함을 접해본 사람들은 더 많은 수도 설치를 원했고 행정 권력도 이에 동의하였다. 그러나 결과적으로 경성의 기반 시설인 수도망의 설치 완비는 실현되지 못했다. ‘경성’에서 ‘서울’로 전환되는 시기에도 물장수는 여전히 존재했고, 수돗물 및 그에 대한 법령이 ‘물’에 대한 전통적 사상과 의식의 패러다임을 바꿨지만 정말 수돗물이 위생적인지는 논란의 여지가 있다. 하지만 수도가 설치되면서 벌어진 다양한 논의, ‘위생’담론, ‘부엌의 근대화’. ‘생활의 과학과’ 등과 같은 경성 사람들의 의식전환과 일상을 바꿔 놓는 데에는 일정한 역할을 수행했다고 생각된다. Tap water which came into existence in 1908 was provided to the people in Gyeongseong(Seoul) through many laws after that. This made it illegal to use water carelessly or pollute water. Only administrative agencies could establish water facilities and protect water to distribute it to people for use. Large and small traditional ceremonies related to traditional water or activities. Water-sellers who sold tap water to the people in need of water before the appearance of tap water continued water supply business using it even after the establishment of modern water supply. The dominant colonial power tried to prevent the business of water-sellers, but, it is thought that it was difficult to completely suppress it due to the substantive and sharp character problem of incomplete establishment of water supply within Gyeonseong and ethnic conflicts. Moreover, it is thought that it was more so because the demand of the water-sellers for a guarantee for business rights was linked with the education rights of the proletarian classes in society as well as the problem of the right to life. Meanwhile, the reason for having positively accepted tab water and tab-related laws and regulations, etc. was because of hygienic aspects. The discourse of hygiene was a Japanese idea of making Koreans ‘dirty’ during that time, but since a cholera epidemic in 1920s, it has become a modern and scientific idea of saving people’s lives. Therefore, the people in Gyeongseong positively mastered the discourse on hygiene and practiced it. As part of practice, the use of tap water increased faster than ever before. Many store using of tap water were located on the streets of Gyeongseong. It is thought that restaurants, barbershops, public baths, laundries, cafes, ice flake shops, etc. Made Gyeongseong’s hot spots and they led the lives of Gyeongseong people to become more urbanized. Of course, these were available only in places where water supplies were established, but the people who had been exposed to living convenience wanted more water supplies established and the administrative power agreed to it. Eventually, however, the completion of the establishment of water supplies, the infrastructure of Gyeongseong, failed to materialize. Even when ‘Gyeongseong’ turned into ‘Seoul’, water-sellers still existed, and the law for tab water and something about it changed the traditional thoughts and awareness paradigm for ‘water’. But it is debatable whether tab water is really hygienic. However, it is thought that the establishment of water supplies played a considerable role in converting the consciousness and daily lives of Gyeongseong people through multiple discussions-‘the discourse of hygiene’. ‘the modernization of a kitchen’. ‘scientific movement of life’. etc.

파일럿 규모 연소기에서 밀짚 펠렛 혼소 시 첨가제에 따른 회 점착의 특성 연구

박유미(Yumi Park),임호(Ho Lim),채태영(Taeyoung Chae),이재욱(Jaewook Lee),고대홍(Dae-hong Ko),양원(Won Yang) 한국열환경공학회 2019 한국열환경공학회 학술대회지 Vol.2019 No.춘계

최근 국내 미활용 바이오매스에 대한 관심이 증가하고 있고 미분탄 보일러에 적용 가능성을 타진하고 있다. 그러나 미분탄 보일러에 바이오매스 혼소 적용 시 회 발생은 중요한 문제로 이를 감소시키는 것은 보일러의 효율적인 운전을 위해 반드시 필요하다. 따라서 본 연구의 목적은 회 점착에 영향을 미칠 수 있는 다양한 첨가제에 따라 석탄, 바이오매스 혼소 시 발생하는 회 점착 특성, 특히 증저감 특성을 규명하는 것이다. 본 연구에서 사용된 바이오매스는 초본계로 밀짚 펠렛(straw pellet)이다. 첨가제로는 카올린(Al2Si2O5(OH)4), 황산암모늄((NH4)2SO4), 인산수소칼슘(CaHPO4), 산화 알루미늄 (Al2O3), 산화 칼슘(CaO)을 선택하여 비교하였다. 연료의 공업분석, 원소분석 및 ICP 등의 기초 분석을 수행하여 연료 특성을 확인하였다. 분석 결과를 바탕으로 80kWth 설비를 사용하여 바이오매스와 석탄 혼소 시 회 점착 거동을 조사하였다. 회 점착 생성 정도는 실시간 무게 측정이 가능한 측정 장비(on-line deposit measuring system)를 활용하여 회 점착량을 측정하였으며, 첨가제에 따른 회 점착 무게를 비교하였다. 그리고 다양한 첨가제 사용에 따른 메커니즘을 분석하기 위해 회 점착을 SEM/EDS 분석을 수행하였다. 결과적으로 동일한 연료가 사용되더라도 첨가제의 종류에 따라 회 점착 형성 메커니즘의 차이로 인해 회 점착을 촉진 또는 억제하는 다양한 결과가 발생함을 확인하였다.

감정노동자의 자기자비가 회복탄력성 및 주관적 안녕감에 미치는 영향

박유미 ( Yumi Park ),조동혁 ( Donghyuk Jo ) 인문사회 21 2023 인문사회 21 Vol.14 No.1

연구 목적: 이 연구는 감정노동자의 자기자비가 회복탄력성과 주관적 안녕감에 미치는 영향과 이들 영향 관계에서 회복탄력성의 매개효과에 대하여 검증하고자 하였다. 연구 방법: 감정노동자를 대상으로 총 396부의 설문자료를 수집하여 분석하고 가설을 검증하였다. 연구 내용: 자기자비로서 자기자비적 태도는 회복탄력성과 주관적 안녕감에 정(+)의 영향을 미치며, 자기비판적 태도는 회복탄력성과 주관적 안녕감에 부(-)의 영향을 미치는 것으로 나타났다. 회복탄력성은 주관적 안녕감에 정(+)의 영향을 미치는 것으로 나타났다. 결론 및 제언: 본 연구를 통하여 감정노동자의 자기자비 함양의 중요성을 확인하였으며 회복탄력성과 주관적 안녕감 증진을 위한 훈련 및 프로그램 개발에 있어 방향성을 제시하였다. This study aimed to verify the effect of emotional workers’ self-compassion on resilience and subjective well-being and the mediating effect of resilience in the relationship between these influences. A total of 396 questionnaires were collected and analyzed for emotional workers, and hypotheses were verified. As self-compassion, a self-compassionate attitude has a positive effect on resilience and subjective well-being, and a self-critical attitude has a negative effect on resilience and subjective well-being. Resilience was found to have a positive effect on subjective well-being. Through this study, the importance of cultivating emotional workers’ self-compassion was confirmed, and a direction was suggested in the development of training and programs to enhance resilience and subjective well-being.