Occurrence and diet analysis of sea turtles in Korean shore

Kim, Jihee,Kim, Il-Hun,Kim, Min-Seop,Lee, Hae Rim,Kim, Young Jun,Park, Sangkyu,Yang, Dongwoo The Ecological Society of Korea 2021 Journal of Ecology and Environment Vol.45 No.1

Background: Sea turtles, which are globally endangered species, have been stranded and found as bycatch on the Korean shore recently. More studies on sea turtles in Korea are necessary to aid their conservation. To investigate the spatio-temporal occurrence patterns of sea turtles on the Korean shore, we recorded sampling locations and dates, identified species and sexes and measured sizes (maximum curved carapace length; CCL) of collected sea turtles from the year 2014 to 2020. For an analysis of diets through stomach contents, we identified the morphology of the remaining food and extracted DNA, followed by amplification, cloning, and sequencing. Results: A total of 62 stranded or bycaught sea turtle samples were collected from the Korean shores during the study period. There were 36 loggerhead turtles, which were the dominant species, followed by 19 green turtles, three hawksbill turtles, two olive ridley turtles, and two leatherback turtles. The highest numbers were collected in the year 2017 and during summer among the seasons. In terms of locations, most sea turtles were collected from the East Sea, especially from Pohang. Comparing the sizes of collected sea turtles according to species, the average CCL of loggerhead turtles was 79.8 cm, of green turtles was 73.5 cm, and of the relatively large leatherback turtle species was 126.2 cm. In most species, the proportion of females was higher than that of males and juveniles, and was more than 70% across all the species. Food remains were morphologically identified from 19 stomachs, mainly at class level. Seaweeds were abundant in stomachs of green turtles, and Bivalvia was the most detected food item in loggerhead turtles. Based on DNA analysis, food items from a total of 26 stomachs were identified to the species or genus level. The gulfweed, Sargassum thunbergii, and the kelp species, Saccharina japonica, were frequently detected from the stomachs of green turtles and the jellyfish, Cyanea nozakii, the swimming crab, Portunus trituberculatus, and kelps had high frequencies of occurrences in loggerhead turtles. Conclusions: Our findings support those of previous studies suggesting that sea turtles are steadily appearing in the Korean sea. In addition, we verified that fish and seaweed, which inhabit the Korean sea, are frequently detected in the stomach of sea turtles. Accordingly, there is a possibility that sea turtles use the Korean sea as feeding grounds and habitats. These results can serve as basic data for the conservation of globally endangered sea turtles.

Generation of a Human Monoclonal Antibody to Cross-Reactive Material 197 (CRM₁₉₇) and Development of a Sandwich ELISA for CRM₁₉₇ Conjugate Vaccines

( Dain Kim ),( Hyeseon Yoon ),( Sangkyu Kim ),( Jimin Wi ),( Heesu Chae ),( Gyunghee Jo ),( Jun-yeol Yoon ),( Heeyoun Kim ),( Chankyu Lee ),( Se-ho Kim ),( Hyo Jeong Hong ) 한국미생물 · 생명공학회 2018 Journal of microbiology and biotechnology Vol.28 No.12

Cross-reactive material 197 (CRM₁₉₇) is a non-toxic mutant of diphtheria toxin containing a single amino acid substitution of glycine 52 with glutamic acid. CRM₁₉₇ has been used as a carrier protein for poorly immunogenic polysaccharide antigens to improve immune responses. In this study, to develop a sandwich ELISA that can detect CRM₁₉₇ and CRM₁₉₇ conjugate vaccines, we generated a human anti-CRM₁₉₇ monoclonal antibody (mAb) 3F9 using a phage-displayed human synthetic Fab library and produced mouse anti-CRM197 polyclonal antibody. The affinity (K_D) of 3F9 for CRM₁₉₇ was 3.55 nM, based on Bio-Layer interferometry, and it bound specifically to the B fragment of CRM₁₉₇. The sandwich ELISA was carried out using 3F9 as a capture antibody and the mouse polyclonal antibody as a detection antibody. The detection limit of the sandwich ELISA was <1 ng/ml CRM₁₉₇. In addition, the 3F9 antibody bound to the CRM₁₉₇-polysaccharide conjugates tested in a dose-dependent manner. This ELISA system will be useful for the quantification and characterization of CRM₁₉₇ and CRM₁₉₇ conjugate vaccines. To our knowledge, this study is the first to generate a human monoclonal antibody against CRM197 and to develop a sandwich ELISA for CRM₁₉₇ conjugate vaccines.

한국 청년세대의 꿈-자본 측정

김석호(Seokho Kim),주윤정(YunJeong Joo),성연주(YunJoo Sung),김지애(Jeeae Kim),김은지(EunJi Kim),이상규(Sangkyu Lee),김홍중(HongJung Kim) 한국문화사회학회 2017 문화와 사회 Vol.24 No.-

이 연구는 한국의 청년세대가 미래를 꿈꾸는 방식과 연관된 여러 중요한 내용들을 서베이를 활용하여 측정, 탐구하는 것을 목적으로 한다. 연구의 이론적 바탕에는 꿈-자본의 개념이 있다. 부르디외의 자본 개념을 적극적으로 활용하며, 우리는 행위자가 미래를 상상하는 힘, 희망의 감정을 품는 힘, 낙관적 태도를 견지하는 힘, 그리고 난관을 이겨가는 힘으로 구성된 총체적 능력인 꿈-자본을 형성하여 다른 자본들을 향한 동기로 활용한다는 관점을 취하고, 이를 실증적으로 탐구해 보고자 한다. 또한 청년세대가 꿈을 이루어 가는 경로와 꿈의 내용, 그리고 꿈을 경영하는 방식에 대한 탐구도 시도한다. 이를 통해 이 연구는 한국 청년의 미래 표상에 대한 경험적 탐구를 위한 기초를 마련해 보고자 한다. 꿈-자본 연구는 청년의 이질성을 분석하는데 중요한 실마리를 제공하고 있다. 기초적 분석 결과는 청년세대의 꿈이 이질화되어가고 있다는 것을 보여주고 있으며, 교육수준의 차이가 중요한 역할을 하고 있음을 시사한다. This research explores the various ways in which the young generation in South Korea today dream about their future, using the survey questionnaires specifically designed for this purpose. “Dreamcapital” serves as a theoretical framework in the research. Building on Bourdieu’s concept of capital, this study theorizes that dream-capital functions like a seed, facilitating the accumulation of other capitals. It is composed of four dimensions: imagination, hope, optimism and resilience. Furthermore, this study examines the process of dream formation and management as well as its content. This paper aims to lay the foundations for further research on the dream and values of this young population. The research on dream-capital helps examine the divergence within the young generation. The basic analysis indicates that the ways in which the young population dream about their future vary, and a significant portion of this variation is explained by the difference in the educational attainment.

Optogenetic control of endogenous Ca²⁺ channels in vivo

Kyung, Taeyoon,Lee, Sangkyu,Kim, Jung Eun,Cho, Taesup,Park, Hyerim,Jeong, Yun-Mi,Kim, Dongkyu,Shin, Anna,Kim, Sungsoo,Baek, Jinhee,Kim, Jihoon,Kim, Na Yeon,Woo, Doyeon,Chae, Sujin,Kim, Cheol-Hee,Shin, Nature Publishing Group, a division of Macmillan P 2015 Nature biotechnology Vol.33 No.10

Calcium (Ca<SUP>2+</SUP>) signals that are precisely modulated in space and time mediate a myriad of cellular processes, including contraction, excitation, growth, differentiation and apoptosis. However, study of Ca<SUP>2+</SUP> responses has been hampered by technological limitations of existing Ca<SUP>2+</SUP>-modulating tools. Here we present OptoSTIM1, an optogenetic tool for manipulating intracellular Ca<SUP>2+</SUP> levels through activation of Ca<SUP>2+</SUP>-selective endogenous Ca<SUP>2+</SUP> release−activated Ca<SUP>2+</SUP> (CRAC) channels. Using OptoSTIM1, which combines a plant photoreceptor and the CRAC channel regulator STIM1 (ref. 4), we quantitatively and qualitatively controlled intracellular Ca<SUP>2+</SUP> levels in various biological systems, including zebrafish embryos and human embryonic stem cells. We demonstrate that activating OptoSTIM1 in the CA1 hippocampal region of mice selectively reinforced contextual memory formation. The broad utility of OptoSTIM1 will expand our mechanistic understanding of numerous Ca<SUP>2+</SUP>-associated processes and facilitate screening for drug candidates that antagonize Ca<SUP>2+</SUP> signals.

Strain rate effects on the compressive and tensile behavior of bundle-type polyamide fiber-reinforced cementitious composites

Kim, Hongseop,Kim, Gyuyong,Lee, Sangkyu,Son, Minjae,Choe, Gyeongcheol,Nam, Jeongsoo Elsevier 2019 Composites. Part B, Engineering Vol.160 No.-

<P><B>Abstract</B></P> <P>The compressive and tensile behavior of fiber-reinforced cementitious composites is significantly affected by the bonding and pull-out properties between matrix and reinforced fiber, as well as the fracture properties of the fibers. In addition, an increase in strain rate according to loading conditions influences the fracture behavior between the fiber and matrix. Steel fiber-reinforced cementitious composites with high flexural and tensile strength, toughness, and crack resistance are widely used in tunnels and plant structures. However, the high specific gravity and stiffness of steel fibers can cause rupture of concrete pump tubes, increase the rebound volume of shotcrete, and decrease durability by corrosion of fiber. Therefore, it is necessary to study the development and application of organic fiber which has similar mechanical properties to steel fiber and does not cause corrosion. In this study, polyamide fibers having the same aspect ratio as the hooked steel fibers, which are widely used as reinforcing fibers for concrete, have been developed. And strain rate effect on the compressive and tensile behaviors of bundle-type polyamide fiber-reinforced cementitious composite and hooked steel fiber-reinforced cementitious composite were evaluated. The results showed that the effect of strain rate over different fiber types influenced the tensile behavior more significantly than the compressive behavior. In polyamide fiber-reinforced cementitious composite (PAFRCC), a fracture behavior of fiber was observed regardless of a strain rate, and the tensile behavior of PAFRCC was influenced more by tensile strength of polyamide fiber itself than a bonding stress between fiber and matrix. In hooked steel fiber-reinforced cementitious composite (HSFRCC), a bonding stress between hooked steel fiber and matrix (frictional force at the interface between fiber and matrix, mechanical bond of the hooked part) influenced the tensile behavior significantly. Fracture properties that straightened pulled out the fiber from the matrix were observed at static tensile loading condition. However, non-straightened hooked steel fiber was observed along with the fracture of matrix due to an increase in mechanical bonding force of the hooked part and the bonding stress between the fiber and the matrix.</P>

Selective Inhibition of Bakuchicin Isolated from <i> Psoralea corylifolia</i> on CYP1A in Human Liver Microsomes

Kim, Sun Joo,Oh, Heung Chan,Kim, Youn-Chul,Jeong, Gil-Saeng,Lee, Sangkyu Hindawi Publishing Corporation 2016 Evidence-based Complementary and Alternative Medic Vol.2016 No.-

<P>Bakuchicin is a furanocoumarin isolated from<I> Psoralea corylifolia</I> and shows several biological activities. Although there have been studies on the biological effects of bakuchicin, its modulation potency of CYP activities has not been previously investigated. Here, we investigated the inhibitory effects of bakuchicin on the activities of CYP isoforms by using a cocktail of probe substrates in pooled human liver microsomes (HLMs) and human recombinant<I> cDNA-expressed</I> CYP. Bakuchicin strongly inhibited CYP1A-mediated phenacetin<I> O</I>-deethylation with an IC<SUB>50</SUB> value of 0.43 <I>μ</I>M in HLMs. It was confirmed by human recombinant<I> cDNA-expressed</I> CYP1A1 and CYP1A2 with a <I>K</I><SUB><I>i</I></SUB> value of 0.11 <I>μ</I>M and 0.32 <I>μ</I>M, respectively. A Lineweaver-Burk plot indicated that the inhibition mechanism of bakuchicin was competitive inhibition. Overall, this is the first study to investigate the potential CYP1A1 and CYP1A2 inhibition associated with bakuchicin and to report its competitive inhibitory effects on HLMs.</P>

Investigation of selective inhibitory effects of glycyrol on human CYP 1A1 and 2C9

Kim, Sun Joo,Kim, Su Jin,Hong, Miri,Choi, Hyun Gyu,Kim, Jeong Ah,Lee, Sangkyu Informa UK (Informa Healthcare) 2016 Xenobiotica Vol.46 No.10

<P>1. Glycyrol is a coumarin derivative isolated from the roots of Glycyrrhiza uralensis called Gamcho in Korea and commonly used as a sweetener in oriental medicine. Glycyrol shows several biological activities, including anti-oxidative, anti-inflammatory, antibacterial, anti-angiogenic, and anti-allergenic properties. Although there have been studies on the biological effects of glycyrol, the inhibitory effects of glycyrol on cytochrome P450 (CYP) activities have not been investigated. 2. We investigated the inhibitory effects of glycyrol on the activities of CYP isoforms using a cocktail of probe substrates in pooled human liver microsome (HLM) and human recombinant cDNA-expressed CYPs. Glycyrol strongly inhibited CYP1A-mediated phenacetin O-deethylation and CYP2C9-mediated diclofenac 4'-hydroxylation in HLMs, which were the result of competitive inhibition as revealed by a Dixon plot. In addition, glycyrol showed selective inhibition of CYP1A1- and CYP1A2-catalyzed phenacetin O-deethylase activity with a half-maximal inhibitory concentration of (IC50) 1.3 and 16.1 mu M in human recombinant cDNA-expressed CYP1A1 and CYP1A2, respectively. 3. Glycyrol decreased CYP2C9-catalyzed diclofenac 4'-hydroxylation activity with IC50 values of 0.67 mu M in human recombinant cDNA-expressed CYP2C9. This is the first investigation of competitive inhibitory effects on CYP1A1 and CYP2C9 in HLMs.</P>

<i>Enterococcus faecium</i> L-15 Cell-Free Extract Improves the Chondrogenic Differentiation of Human Dental Pulp Stem Cells

Kim, Hyewon,Park, Sangkyu,Kim, Kichul,Ku, Seockmo,Seo, Jeongmin,Roh, Sangho MDPI AG 2019 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.20 No.3

<P>Hyaline cartilage is a tissue of very low regenerative capacity because of its histology and limited nutrient supply. Cell-based therapies have been spotlighted in the regeneration of damaged cartilage. Dental pulp stem cells (DPSCs) are multipotent and are easily accessible for therapeutic purposes. In human gastrointestinal tracts, <I>Enterococcus faecium</I> is a naturally occurring commensal species of lactic acid bacteria. In this work, the human DPSCs were differentiated into chondrocytes using a chondrogenic differentiation medium with or without L-15 extract. We observed that chondrogenic differentiation improved in an <I>E. faecium</I> L-15 extract (L-15)-treated DPSC group via evaluation of chondrogenic-marker mRNA expression levels. In particular, we found that L-15 treatment promoted early-stage DPSC differentiation. Cells treated with L-15 were inhibited at later stages and were less likely to transform into hypertrophic chondrocytes. In L-15-treated groups, the total amount of cartilage extracellular matrix increased during the differentiation process. These results suggest that L-15 promotes chondrogenic differentiation, and that L-15 may be used for cartilage repair or cartilage health supplements. To our knowledge, this is the first report demonstrating the beneficial effect of L-15 treatment on chondrogenic differentiation.</P>

Thin Reading

Sangkyu Kim(김상규) 한국디자인학회 2015 한국디자인학회 국제초대전도록 Vol.2015 No.5

Installation design for Sejong Hospital

Sangkyu Kim(김상규) 한국디자인학회 2018 한국디자인학회 국제초대전도록 Vol.2018 No.6