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Voltammetric Sensor Incorporated with Conductive Polymer, Tyrosinase, and Ionic Liquid Electrolyte for Bisphenol F (전도성고분자, 티로시나아제 효소 및 이온성 액체 전해질을 융합한 전압전류법 기반의 비스페놀F 검출 센서)

  • Sung Eun Ji;Sang Hyuk Lee;Hye Jin Lee
    • Applied Chemistry for Engineering
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    • v.34 no.3
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    • pp.258-263
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    • 2023
  • In this study, conductive polymers and the enzyme tyrosinase (Tyr) were deposited on the surface of a screen printed carbon electrode (SPCE), which can be fabricated as a disposable sensor chip, and applied to the detection of bisphenol F (BPF), an endocrine disruptor with proven links to male diseases and thyroid disorders, using electrochemical methods. On the surface of the SPCE working electrode, which was negatively charged by oxygen plasma treatment, a positively charged conductive polymer, poly(diallyldimethyl ammonium chloride) (PDDA), a negatively charged polymer compound, poly(sodium 4-styrenesulfonate) (PSS), and another layer of PDDA were layered by electrostatic attraction in the order of PDDA, PSS, and finally PDDA. Then, a layer of Tyr, which was negatively charged due to pH adjustment to 7.0, was added to create a PDDA-PSS-PDDA-Tyr sensor for BPF. When the electrode sensor is exposed to a BPF solution, which is the substrate and target analyte, 4,4'-methylenebis(cyclohexa-3,5-diene-1,2-dione) is generated by an oxidation reaction with the Tyr enzyme on the electrode surface. The reduction process of the product at 0.1 V (vs. Ag/AgCl) generating 4,4'-methylenebis(benzene-1,2-diol) was measured using cyclic and differential pulse voltammetries, resulting in a change in the peak current with respect to the concentration of BPF. In addition, we compared the detection performance of BPF using an ionic liquid electrolyte as an alternative to phosphate-buffered saline, which has been used in many previous sensing studies. Furthermore, the selectivity of bisphenol S, which acts as an interfering substance with a similar structure to BPF, was investigated. Finally, we demonstrated the practical applicability of the sensor by applying it to analyze the concentration of BPF in real samples prepared in the laboratory.

Loss of EMP2 Inhibits Melanogenesis of MNT1 Melanoma Cells via Regulation of TRP-2

  • Enkhtaivan, Enkhmend;Kim, Hyun Ji;Kim, Boram;Byun, Hyung Jung;Yu, Lu;Nguyen, Tuan Minh;Nguyen, Thi Ha;Do, Phuong Anh;Kim, Eun Ji;Kim, Kyung Sung;Huy, Hieu Phung;Rahman, Mostafizur;Jang, Ji Yun;Rho, Seung Bae;Lee, Ho;Kang, Gyeoung Jin;Park, Mi Kyung;Kim, Nan-Hyung;Choi, Chang Ick;Lee, Kyeong;Han, Hyo Kyung;Cho, Jungsook;Lee, Ai Young;Lee, Chang Hoon
    • Biomolecules & Therapeutics
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    • v.30 no.2
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    • pp.203-211
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    • 2022
  • Melanogenesis is the production of melanin from tyrosine by a series of enzyme-catalyzed reactions, in which tyrosinase and DOPA oxidase play key roles. The melanin content in the skin determines skin pigmentation. Abnormalities in skin pigmentation lead to various skin pigmentation disorders. Recent research has shown that the expression of EMP2 is much lower in melanoma than in normal melanocytes, but its role in melanogenesis has not yet been elucidated. Therefore, we investigated the role of EMP2 in the melanogenesis of MNT1 human melanoma cells. We examined TRP-1, TRP-2, and TYR expression levels during melanogenesis in MNT1 melanoma cells by gene silencing of EMP2. Western blot and RT-PCR results confirmed that the expression levels of TYR and TRP-2 were decreased when EMP2 expression was knocked down by EMP2 siRNA in MNT1 cells, and these changes were reversed when EMP2 was overexpressed. We verified the EMP2 gene was knocked out of the cell line (EMP2 CRISPR/Cas9) by using a CRISPR/Cas9 system and found that the expression levels of TRP-2 and TYR were significantly lower in the EMP2 CRISPR/Cas9 cell lines. Loss of EMP2 also reduced migration and invasion of MNT1 melanoma cells. In addition, the melanosome transfer from the melanocytes to keratinocytes in the EMP2 KO cells cocultured with keratinocytes was reduced compared to the cells in the control coculture group. In conclusion, these results suggest that EMP2 is involved in melanogenesis via the regulation of TRP-2 expression.

Research Trend of Estuarine Ecosystem Monitoring and Assessment (국내 하구 수생태계 현황 및 건강성 조사의 성과와 하구 생태계의 국외 연구동향)

  • Won, Doo-Hee;Lim, Sung-Ho;Park, Jihyung;Moon, Jeong-Suk;Do, Yuno
    • Korean Journal of Ecology and Environment
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    • v.55 no.1
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    • pp.1-9
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    • 2022
  • An estuary is an area where a freshwater river or stream meets the ocean. Even before the importance of the value of estuaries was recognized, the estuary was lost because of large-scale conversion by draining, filling, damming, and dredging. In South Korea, 643 estuaries are located, and the total area is 3,248,300 ha, accounting for 32.5% of the total area of South Korea. Over 35% of Korean estuaries are closed estuaries which are only temporally connected with the sea, either permanently or periodically. Since 2008, in order to preserve the estuary ecosystem and solve major issues in the estuary by accumulating knowledge about the estuarine ecosystem, the Ministry of Environment of Republic of Korea has been conducting the "Estuarine Ecosystem Monitoring and Assessment Project". At 668 sites of 325 estuaries, epilithic diatom, benthic macroinvertebrate, fish, and vegetation are investigated, and the habitat condition of each site is evaluated using the newly developed biotic index. More than 100 researchers annually record 2,097 species of estuaries according to the standardized survey guidelines over the past 14 years and provide strictly managed data necessary for establishing estuaries conservation policies. As a result of bibliometric analysis of 1,195 research articles related to the monitoring and assessment of the estuarine ecosystem, research on pollutants such as heavy metals and sediment control have recently been conducted. "Estuarine Ecosystem Monitoring and Assessment Project" is an ecological monitoring type of long-term mandated monitoring that is usually focused on identifying trends. Although it is difficult to identify the mechanism influencing a change in an ecosystem through long-term mandated monitoring, providing empirical data for supporting evidence-based policy, decision-making, and the management of ecosystems. In order to increase the efficiency of the project, research to investigate the relationship between sediments and pollutants and organisms can be conducted at specific estuaries or sites to compensate for the shortcomings of mandatory monitoring.

Benthic Macroinvertebrates Inhabiting Estuaries in Sea Area and Relationship with Major Drivers of Change in Estuaries (해역별 하구에 서식하는 저서성 대형무척추동물 현황과 하구 서식지 주요 변화 동인과의 관계)

  • Lim, Sung-Ho;Jung, Hyun-Chul;Lee, Min-Hyuk;Lee, Sang-Wook;Moon, Jeong-Suk;Kwon, Soon-Hyun;Won, Du-Hee
    • Korean Journal of Ecology and Environment
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    • v.55 no.1
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    • pp.10-18
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    • 2022
  • This study analyzed the relationship between the community structure of benthic macroinvertebrates and habitat changes in open estuaries among the sites included in the national estuary monitoring program. The estuary survey was conducted under the "Guidelines for Investigation and Evaluation of Biometric Networks" and classified by sea area, 80 places in the East Sea, 102 places in the South Sea, and 19 places in the West Sea were investigated. In a total of 201 open estuaries, benthic macroinvertebrates were identified with 4 phyla, 9 classes, 41 orders, 139 families, 269 species and 196 species in the East Sea, 182 species in the South Sea, and 90 species in the West Sea. The highest population densities were Insecta in the East Sea, the Malacostraca in the South Sea, and the Annelida in the West Sea. Through SIMPER analysis, species contributing to the similarity of benthic macroinvertebrates communities in each sea area were identified. Some species greatly influenced the similarity of clusters. The benthic community in the East Sea was affected by the salinity, so the contribution rate of freshwater species was high. On the other hand, the benthic communities of the South and West Seas showed species compositions are influenced by the substrate composition. As results, the benthic macroinvertebrate community in Korean estuaries was impacted by salinity and substrate simultaneously, and the close relationship with geographical distance was not observed. The result of this study is expected to be used to respond to environmental changes by identifying and predicting changes in the diversity and distribution of benthic macroinvertebrates in Korea estuaries.

The Relationship between Cultural Self-construal of Korean and Alexithymia: A Serial Mediation Process Model of Ambivalence over Emotion Expression and Emotion Suppression Moderated by Generation (한국인의 문화적 자기관과 감정표현불능증의 관계: 세대에 의해 조절된 정서표현양가성 및 정서억제 연속매개과정 모형)

  • Haejin Kim;Soyoung Kwon;Sunho Jung;Donghoon Lee
    • Korean Journal of Culture and Social Issue
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    • v.29 no.2
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    • pp.171-197
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    • 2023
  • The traditional Korean society has been classified as an Eastern collectivist culture, but in the flow of globalization and digitalization along with the post-Cold War era of the 1970s, Western individualistic culture and values quickly permeated the Korean younger generation. Since rapid changes occurred within a short period of time, there may be differences in cultural self-construal between generations living in the same era. Due to this, psychological problems related to emotional expression and suppression may appear differently depending on generations. Therefore, in the current study, 1,000 Korean adult men and women from their 20s to 60s were investigated for their level of independent and interdependent self-construal, alexithymia, ambivalence over emotional expression(AEE) and emotional suppression(ES). Then the relationship between the variables(self-construal and alexithymia,) and the mediating process of AEE and ES were examined. The generation of participants were divided into the industrialization cohort (birth year < 1970) and the digitalization cohort (birth year starting from 1970). Using the PROCESS macro(Hayes, 2022), we tested a serial mediation model of AEE and ES between the relative independent self-construal(RIS) and alexithymia. The results indicate that the level of alexithymia increases by the serial increase of AEE and ES when RIS decreases. Next, we examined a moderation effect of generatione on the mediation process of AEE and ES, and found that generation moderates the relationship between ES and alexithymia. That is, the effect of ES on alexithymia is significant for the digitalization cohort, while it is not significant for the industrialization cohort. The current results imply that emotion regulation strategies of Koreans have been differently developed according to prevailing cultural values in each generation, and that the negative influence of emotion suppression could be different according to the cultural background of each generation.

Comparative Analysis of Growth, Yield, and Grain Quality of Hulled Barley Grown Under Different Meteorological Conditions in South Korea (기후분포가 다른 재배지에서 생장한 겉보리 생육, 수량 및 품질 비교)

  • Hyun-Hwa Park;Hyo-Jin Lee;Ye-Guon Kim;Dea-Wook Kim;Yong-In Kuk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.68 no.2
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    • pp.69-80
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    • 2023
  • This study investigated the differences in barley growth at different growth stages (Dec, Feb, and Apr) and the yield at harvest in three groups (G1, G2, and G3) with different climates. Additionally, we measured meteorological differences between areas during the growing season to determine which factors were related to growth and yield differences. We evaluated the chemical composition of soil and the mineral content in leaves during the heading stages. We also recorded the main constituents, amino acids, and mineral compositions of barley seeds grown in different areas. Tiller number/m2 in G1 areas was higher than in G2 and G3 when measured before and after overwintering. However, tiller number/m2 and dry aboveground plant parts/m2 in G2 and G3 areas were higher than in G1. Regrowth, panicle formation, and heading days in G2 areas occurred slightly later than in G1 and G3. However, there was no difference in chlorophyll content (SPAD value) between groups. The yield in G1 areas was 9~15% less than in G1 and G3. The decrease in yield in G2 areas could be due to lower panicle number, spikelet number, and ripening rate. In addition, the decrease in yield in G2 areas is likely because maximum, minimum, and average daily temperatures during the growing season were lower than those in G1 and G3. However, mineral nutrients in the soil were higher in the G2 area than in G1 and G3. The overall mineral content in plants tended to be higher in G1 areas than in G2 and G3. Mineral content such as Cu, K, Mg, and P in G3 areas and crude protein and most amino acids in G2 areas tended to be relatively low compared to other areas. Thus, the G1 area may be suitable for barley cultivation without adverse impacts on barley yield, main constituents, amino acids, and mineral contents compared to the main producing areas in G3.

Monitoring of arsenic and arsenic species in fish collagen in Korea (국내 유통 어류 콜라겐의 총비소 및 비소화학종 함량 모니터링)

  • Yeo-Jae Shin;Mi-Ra Jang;Eun-Hee Kim;Yun-Hee Kim;Min-Jung Kim;Min-Jung Kim;Jae-Hoon Cha;Mi-Hyun Choi;Seok-Ju Cho;In-Sook Hwang;Yong-Seung Shin
    • Analytical Science and Technology
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    • v.36 no.3
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    • pp.135-142
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    • 2023
  • The total arsenic and 6 arsenic species were investigated in 56 fish collagen products using ICP-MS (Inductively coupled plasma-mass spectrometer) and HPLC-ICP-MS(High performance liquid chromatography-Inductively coupled plasma-mass spectrometer). The mean concentrations of total arsenic and arsenic species were 40.103±81.133 ㎍/kg (N.D.~586.686) and 30.070±50.378 ㎍/kg (N.D.~313.871), respectively. The mean concentration of inorganic arsenic was 24.610±32.706 ㎍/kg (N.D.~129.331), and the As(V) (Arsenate) was the most dominant. The standards and specifications of arsenic have not been established for fish collagen products. Our study presents that arsenic levels are relatively safe compared with not only previous studies but also domestic and international standards. However, in one sample, the total arsenic concentration was 586.686 ㎍/kg, showing the inorganic was 8.119 ㎍/kg, and the DMA was 305.752 ㎍/kg, which was high than the Canadian standard for organic arsenic. In conclusion, it is necessary to monitor arsenic levels consistently and establish standards and specifications of arsenic in fish collagen products to assure consumer safety.

Lipid Peroxidation and Fertilizing Ability In Vitro by Superoxide Dismutase in Boar Spermatozoa Frozen-Thawed (Superoxide Dismutase에 의한 돼지 동결-융해정자의 Lipid Peroxidation과 체외수정능력)

  • Sa, S.J.;Wee, M.S.;Oh, J.Y.;Cheong, H.T.;Park, S.B.;Yang, B.K.;Kim, C.I.;Park, C.K.
    • Korean Journal of Animal Reproduction
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    • v.25 no.4
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    • pp.327-337
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    • 2001
  • This study investigated the effects of superoxide dismutase (SOD) on lipid peroxidation and fertilizing ability in vitro of boar spermatozoa frozen-thawed. The percentages of motile sperm were highest when SOD of 10 units/$m\ell$ was added to washing medium for spermatozoa. However, the rates of motile sperm were not significantly different in different concentrations of SOD. On the other hand, the motile rates of sperm washed with SOD were lower in sperm inculbated for 120 min than 30 min regardless of the different concentrations of SOD. The percentage of spermatozoa that reached acrosome reaction were increased with incubation periods prolonged. No significant differences, however, were observed in acrosome reaction rates between sperm incubated with and without SOD supplementation for 0, 60 and 120 min. When oocyies inseminated with different concentrations of SOD, the penetration rates were significantly (P<0.05) higher in medium with 1 unit/$m\ell$ than 0, 10 and 100 units/$m\ell$ of SOD. However, the proportions of polyspermit oocytes were significantly (P<0.05) lower in medium with 10 and 100 units/$m\ell$ than 0 unit/$m\ell$ of SOD. In another experiment, the sperm suspension were also treated with different concentrations of SOD and were assayed far sulfhydryl(-SH) group content. In the groups treated with 100 units/$m\ell$ of SOD, sperm-SH group were higher than another groups. However, sperm-SH group content were not siginificantly different in spermatozoa treated with different concentrations of SOD. Under the same conditions, the lipid peroxidation of sperm was evaluated on the basis of malondialdehyde production. The addition of SOD to sperm suspension decreased the formation or malondialdehyde. However, there were not significantly different in sperm treated with different concentrations of SOD. The activity of sperm binding to zona pellucida was also evaluated through binding to salt-stored porcine oocytes. The sperm binding to zona pellucida were gradually increased with SOD concentrations added. The number of spermatozoa binded to zona pellucida were significantly (P<0.05) higher in medium with 100 units/$m\ell$ than 0 units/$m\ell$ of SOD. These findings suggested that SOD cause an enhancement penetrarion ability and sperm zona binding in boar spermatozoa frozen-thawed.

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Biochemical Methane Potential Analysis of Mushroom Waste Medium (버섯 폐배지의 생화학적 메탄퍼텐셜 분석)

  • Kim, Chang-Gyu;Lee, Jun-Hyeong;Yoon, Young-Man
    • Journal of the Korea Organic Resources Recycling Association
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    • v.30 no.1
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    • pp.13-21
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    • 2022
  • Mushroom waste medium refers to the waste biomass generated after mushroom cultivating. And, the burden of treatment on mushroom farmhouse is increasing due to the absence of appropriate treatment method and increase of treatment costs of the mushroom waste medium. In this study, in order to assess the energy value of mushroom waste medium by an anaerobic digestion, methane potential and anaerobic organic matter decomposition characteristics were investigated. The theoretical methane potential(Bth) of mushroom medium(MM) was 0.481 Nm3-CH4/kg-VSadded, and the Bth of mushroom waste medium(MWM) was 0.451 Nm3-CH4/kg-VSadded. The biochemical methane potential(Bu-exp) of MWM was increased by 18% from 0.155 for MM to 0.183 Nm3-CH4/kg-VSadded for MWM. In the reaction kinetics analysis by the Modified Gompertz model, the maximum methane production rate(Rm) was increased from 4.59 for MM to 7.21 mL/day for MWM and the lag growth phase time(λ) was decreased from 2.78 for MM to 1.96 days for MWM. In the reaction kinetics analysis by the parallel first order kinetics model, the easily degradable organic matter(VSe) content was increased by 5.89% and the persistently degradable organic matter(VSp) content was 2.03% in MWM, and the non-degradable organic matter(VSNB) content was decreased by 7.85%. Therefore, it was evaluated that the anaerobic digestion efficiency of MWM was increased. The anaerobic digestion efficiency of MWM was assessed to be more improved than that of MM.

Current status of cherry trees (Prunus subg. Cerasus) planted in Korea: A case study of Bundang Central Park and adjacent area (국내 벚나무류(Prunus subg. Cerasus) 식재 현황: 분당중앙공원 일대 사례연구)

  • HAN, Byungwoo;JUNG, Jongduk;NA, Hye Ryun;KANG, Kyoungsuk;CHANG, Hany;KIM, Seryoung;KIM, Youme;KWON, Heejeong;HYUN, Jin-Oh
    • Korean Journal of Plant Taxonomy
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    • v.52 no.1
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    • pp.54-63
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    • 2022
  • Prunus subg. Cerasus is the most planted street and landscaping tree in South Korea, but it is difficult to identify species according to their macro-morphologies, leading to problems when attempting properly to manage species quantities. The purpose of this study is to understand the current status of plant types and species compositions in Bundang Central Park in Bundang-gu of Seongnam City and to discuss the necessity of the management of landscaping tree planting. In April of 2021, during the cherry blossom season, a total of 5,866 planted cherry trees were investigated within an area of 6 km2 of Bundang-gu in Seongnam City. As a result, 5,744 trees were sorted into eleven taxa, but the remaining 122 trees were not determined due to their complex morphologies. Prunus ×yedoensis Matsum. accounted for the highest proportion (52.1%), followed by P. serrulata Lindl. var. pubescens Nakai and P. jamasakura Siebold ex Koidz. P. ×nudiflora (Koehne) Koidz., a plant native to Jejudo Island, was not found in this survey. In order to help identify cherry trees based on micro-morphologies, an identification key was presented for the eleven taxa planted as major landscaping trees. It is known that cherry trees frequently form interspecific hybrids in nature. In order to prevent a loss of the genetic originality of native species due to hybridization and gene introgression from foreign cherry trees, it is necessary to manage planting species near the habitats of native taxa and track their origins.