Chimeric singleton placenta consisting of normal/placental mesenchymal dysplasia and complete hydatidiform mole, associated with successful normal male baby delivery and GTN in postpartum

( Seungyeon Song ),( Ji Hye Koh ),( Ok Ju Kang ),( Dasol Oh ),( Sang-hun Lee ),( Soo-jeong Lee ),( Jun-woo Ahn ),( Hyun-jin Roh ),( Jeong Sook Kim ) 대한산부인과학회 2022 대한산부인과학회 학술대회 Vol.108 No.-

Placental mesenchymal dysplasia (PMD) is a rare but benign placental lesion combined with placentomegaly, grape-like cystic lesion and villous hyperplasia. It is usually accepted that PMD is a different benign disease from other kinds of hydatidiform moles such as complete (CHM) or partial (PHM) hydatidiform mole which are usually misdiagnosed as PMD. Here, we report a special case of PMD combined with CHM in a singleton placenta with live birth. The mother had an abnormally high level of msHCG in early pregnancy with the ultrasonography demonstrated multiple cystic lesions with placentomegaly. The msHCG level decreased within a normal range, and no fetal structural abnormality was observed. After successful delivery of a healthy male baby at 34 weeks of GA, placenta immunostaining of p57KIP2 (CDKN1C) and short tandem repeat (STR) analysis revealed the existence of three distinct histologic and genetic features such as normal baby and placenta tissue, PMD, and CHM in a single placenta. The mother was diagnosed with gestational trophoblastic neoplasia (GTN) and had treatment up to the third-line chemo therapy.

석탄발전 연료암모니아의 정량적 위험성평가기반 사고영향 분석

정승연(Seungyeon Jeong),정희섭(Huiseop Jeong),서동균(Dongkyun Seo) 한국연소학회 2023 KOSCOSYMPOSIUM논문집 Vol.2023 No.11

자동차 개발 프로세스에서의 보안 내재화 방법론

정승연 ( Seungyeon Jeong ),강수영 ( Sooyoung Kang ),김승주 ( Seungjoo Kim ) 한국정보처리학회 2020 정보처리학회논문지. 소프트웨어 및 데이터 공학 Vol.9 No.12

기존의 자동차 개발은 주로 정확성(Correctness) 및 안전성(Safety) 확보에 초점을 맞추어 왔으며, 이에 반해 보안성(Security)은 비교적 소홀하게 다루어져 왔다. 하지만 최근 자동차의 인터넷 연결성이 높아짐에 따라 자동차 해킹 사례가 증가하면서, 유엔유럽경제위원회(United Nations Economic Commission for Europe, UNECE)와 같은 국제기관은 자동차 개발에 대한 보안성을 확보하기 위해 사이버보안 규제를 준비하고 있다. 다른 IT 제품과 마찬가지로 자동차 사이버보안 규제에서 또한 개발 초기부터 보안성을 고려하는 “보안 내재화(Security by Design)”의 개념을 강조한다. 특히 자동차 개발은 생명주기가 길고 공급망이 복잡하기 때문에 개발 이후에 아키텍처를 변경하는 것이 매우 어려우므로, 자동차 개발에 있어 보안 내재화는 기존 IT 제품에 비해 훨씬 더 중요시된다. 그러나 문제는 아직 자동차 개발 과정에 보안을 내재화하는 구체적인 방법론이 제시되지 못하고 있다는 것이다. 이에 본 논문에서는 자동차 보안 내재화를 위한 구체적인 방법론을 제안한다. 본 논문에서 제안된 방법론을 통해 자동차 제조사는 자동차 개발 과정에 있어 기능 안전성과 보안성의 측면을 동시에 고려할 수 있으며, 다가오는 UNECE 자동차 사이버보안 규제에 대한 인증에도 대응할 수 있을 것이다. Conventional automotive development has mainly focused on ensuring correctness and safety and security has been relatively neglected. However, as the number of automotive hacking cases has increased due to the increased Internet connectivity of automobiles, international organizations such as the United Nations Economic Commission for Europe(UNECE) are preparing cybersecurity regulations to ensure security for automotive development. As with other IT products, automotive cybersecurity regulation also emphasize the concept of "Security by Design", which considers security from the beginning of development. In particular, since automotive development has a long lifecycle and complex supply chain, it is very difficult to change the architecture after development, and thus Security by Design is much more important than existing IT products. The problem, however, is that no specific methodology for Security by Design has been proposed on automotive development process. This paper, therefore, proposes a specific methodology for Security by Design on Automotive development. Through this methodology, automotive manufacturers can simultaneously consider aspects of functional safety, and security in automotive development process, and will also be able to respond to the upcoming certification of UNECE automotive cybersecurity regulations.

Fatty acid oxidation regulates cellular senescence by modulating the autophagy-SIRT1 axis

( Seungyeon Yang ),( Subin Moon ),( Soojung Claire Hur ),( Seung Min Jeong ) 생화학분자생물학회 2023 BMB Reports Vol.56 No.12

Senescence, a cellular process through which damaged or dysfunctional cells suppress the cell cycle, contributes to aging or age-related functional decline. Cell metabolism has been closely correlated with aging processes, and it has been widely recognized that metabolic changes underlie the cellular alterations that occur with aging. Here, we report that fatty acid oxidation (FAO) serves as a critical regulator of cellular senescence and uncover the underlying mechanism by which FAO inhibition induces senescence. Pharmacological or genetic ablation of FAO results in a p53-dependent induction of cellular senescence in human fibroblasts, whereas enhancing FAO suppresses replicative senescence. We found that FAO inhibition promotes cellular senescence through acetyl-CoA, independent of energy depletion. Mechanistically, increased formation of autophagosomes following FAO inhibition leads to a reduction in SIRT1 protein levels, thereby contributing to senescence induction. Finally, we found that inhibition of autophagy or enforced expression of SIRT1 can rescue the induction of senescence as a result of FAO inhibition. Collectively, our study reveals a distinctive role for the FAO-autophagy-SIRT1 axis in the regulation of cellular senescence. [BMB Reports 2023; 56(12): 651-656]

Electrochemical characteristics of La0.8Sr0.2MnO3 (LSM)–scandia-stabilized zirconia (ScSZ) composite cathode

Jeong Hyeongwon,SHARMA BHARAT,Jo Seungyeon,Kim Yo Han,Myung Jae-Ha 한국세라믹학회 2022 한국세라믹학회지 Vol.59 No.4

LSM–ScSZ composite electrode for solid oxide fuel cells (SOFCs) cathode application has been investigated for its oxy- gen reduction reaction (ORR) performance. The composition and sintering temperature of LSM–ScSZ were controlled to determine the optimized microstructure of the LSM–ScSZ electrode layer, considering its length of triple-phase boundaries (TPBs), and transfer of oxygen for cathode reaction. The electrochemical impedance spectroscopy (EIS) method with an equivalent circuit model was introduced to characterize the specifi c impedance of each sample. The results demonstrated that volume ratio of LSM:ScSZ = 6:4 sintered at 1200 °C sample showed the lowest total impedance of 0.031 Ω  cm 2 at 900 °C operating temperature, compensating slightly increased high-frequency impedance ( R HF ) of TPBs region with drastically improved the active surface of LSM area and their connectivity, which correspond to middle- and low-frequency impedance ( R MF and R LF ) value, respectively. This study suggests an integrated approach in the development of the SOFCs cathode design with the proper compositional ratio and sintering process via using commercial materials.

Cryogenic Tensile Behavior of Ferrous Medium-entropy Alloy Additively Manufactured by Laser Powder Bed Fusion

Seungyeon Lee,Kyung Tae Kim,Ji-Hun Yu,Hyoung Seop Kim,Jae Wung Bae,Jeong Min Park 한국분말재료학회(구 한국분말야금학회) 2024 한국분말재료학회지 (KPMI) Vol.31 No.1

The emergence of ferrous-medium entropy alloys (FeMEAs) with excellent tensile properties represents a potential direction for designing alloys based on metastable engineering. In this study, an FeMEA is successfully fabricated using laser powder bed fusion (LPBF), a metal additive manufacturing technology. Tensile tests are conducted on the LPBF-processed FeMEA at room temperature and cryogenic temperatures (77 K). At 77 K, the LPBF-processed FeMEA exhibits high yield strength and excellent ultimate tensile strength through active deformation-induced martensitic transformation. Furthermore, due to the low stability of the face-centered cubic (FCC) phase of the LPBFprocessed FeMEA based on nano-scale solute heterogeneity, stress-induced martensitic transformation occurs, accompanied by the appearance of a yield point phenomenon during cryogenic tensile deformation. This study elucidates the origin of the yield point phenomenon and deformation behavior of the FeMEA at 77 K.

ChIP-seq analysis reveals alteration of H3K4 trimethylation occupancy in cancer-related genes by cold atmospheric plasma

Lee, Seungyeon,Park, Sungbin,Lee, Hyunkyung,Jeong, Dawoon,Ham, Juyeon,Choi, Eun Ha,Kim, Sun Jung Elsevier 2018 FREE RADICAL BIOLOGY AND MEDICINE Vol.126 No.-

<P><B>Abstract</B></P> <P>Cold atmospheric plasma (CAP) has gained attention for use in cancer treatment owing to its ability to preferentially induce cancer cell death; however, the involved molecular mechanism remains to be elucidated. Herein, an epigenetic effect of CAP on cancer cells was examined by performing a genome-wide ChIP-seq for H3K4me3 in MCF-7 breast cancer cell line. Consequently, 899 genes showed significantly changed methylation level at H3K4 with constructing “Cellular Compromise, DNA Replication, Recombination, Repair, and Cell Cycle” as the top network. Comparisons with expression array data revealed a coincidence between histone modification and gene expression for 18 genes, and the association was confirmed by ChIP-PCR and qRT-PCR for selected genes. The expression of the affected genes, such as <I>HSCB</I> and <I>PRPS1,</I> was recovered when a histone demethylase JARID1A was inhibited. Furthermore, JARID1A was induced by CAP via the reactive oxygen species signaling. The two genes are known as oncogenes and show a higher expression in breast cancer tissue, and this was supported by the decreased colony formation ability of MCF-7 cells when the cells were treated with siRNAs against each gene. Taken together, these data indicate that CAP inhibits cancer cell proliferation by modulating the methylation level of H3K4 corresponding to oncogenes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cold atmospheric plasma induced genome-wide alteration of H3K4me3 in the MCF-7. </LI> <LI> The H3K4me3 of HSCB and PRPS1 was increased by cold atmospheric plasma. </LI> <LI> Inhibition of a histone demethylase (JARID1A) recovered expression of HSCB and PRPS1. </LI> <LI> Cold atmospheric plasma inhibits cancer cell proliferation by modulating H3K4me3. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

포스트 Z세대를 위한 미래 교육평가의 방향

이승연(Seungyeon Lee),정영현(Younghyun Jung),이정연(Jeong Youn Lee) 학습자중심교과교육학회 2021 학습자중심교과교육연구 Vol.21 No.20

목적 이 연구는 새롭게 등장하는 알파세대(2010년 이후 출생)로의 세대 전환의 경계에 있는 Z세대의 세대 특성과 교육 평가에 관한 학생 및 교사의 경험을 탐구하고, 미래 세대의 교육평가 변화 방향성에 대한 시사점을 도출하고자 한다. 방법 이 연구는 설명적 순차 설계를 통한 혼합연구방법을 활용해 연구를 수행하였다. 먼저 알파세대 및 Z세대에 대한 문헌검토, 사전설문, 전문가 의견 검토 등을 통해 개발한 설문조사를 통해 교사 81명과 학생 197명의 응답을 분석한 후, 도출된 연구결과의 해석을 보완하기 위해 교사 4명과 학생 9명을 대상으로 반구조화 면담을 수행하였다. 연구진은 양적 및 질적 자료에 기반한 토의 및 통합적 해석을 통해 결론을 도출하였다. 결과 연구 결과 포스트 Z세대는 크게 다섯 가지의 세대 특징을 공유하고 있는 한편, 교사와 학생 간에 해석의 차이가 있는 것으로 나타났다. 또한, 선호하는 평가의 과정도 교사와 학생 간에 대체로 차이가 있었다. 결론 이와 같이 교사와 학생들의 인식 차이를 중심으로 분석한 미래세대의 교육평가 방안은 다섯 가지로 정리되었다. 특히 미래세대의 교육평가에 대한 최근의 다양한 시도와 방안이 현장에서 어떠한 요인 때문에 실천에 어려움이 있는지를 탐구함으로써 이를 개선할 수 있는 방향을 제시하고자 한다. Objectives This research explored the features of Post-generation Z - which is the generation cohort that belongs in the borders of change to the new Generation Alpha (generation cohort born after 2010) - and compared the perception that students and teachers have regarding their experience with the Generation. This research aims to bring out implications to how school assessment could change for the following generation. Methods The research was conducted through a sequential explanatory design research model. First, a survey on school assessment for Post-generation Z was designed by reviewing previous research, pre-surveys, and expert group reviews. Response of 81 teachers and 197 students were analyzed, and interviews of four teachers and nine students were analyzed to supplement the comprehension of results from the survey. The researchers reached the conclusion through discussion on the thorough interpretation of the overall responses. Results There were five main characteristics to Post-generation Z, but the interpretation of teachers and students had some differences. Also, their perception of the factors of assessment was found to have differences. Conclusions According to the results, the research provides five main implications to where school assessment for future generations should head. Especially, this research focus on why current attempts at school assessment reform have encountered difficulties on-site and how they could be solved.

EPB ACTUATOR에 적용된 GEAR TYPE의 CLAMPING FORCE 영향성에 대한 연구

한승연(Seungyeon Han),정수진(Sujin Jeong),박강우(Kangwoo Park),김동우(Dongwoo Kim),노의동(Euidong Ro),이창훈(Changhoon Lee) 한국자동차공학회 2016 한국자동차공학회 학술대회 및 전시회 Vol.2016 No.11

Morphology control of noble metal catalysts from planar to dendritic shapes by galvanic displacement

Baek, Seungyeon,Kim, Kwang Hwan,Kim, Myung Jun,Kim, Jae Jeong Elsevier 2017 Applied Catalysis B Vol.217 No.-

<P><B>Abstract</B></P> <P>Noble metal electrocatalysts can simply be prepared via galvanic displacement method on a sacrificial substrate, which is advantageous for preparing a uniform and thin catalyst layer. However, it is difficult to control the morphology of deposited metals via galvanic displacement, therefore, there is a limitation to increase the surface area of electrocatalysts. In this study, we demonstrate galvanic displacement for controlling the morphology of Pd, Pt, and Au from planar to whisker shapes by manipulating the dissolution rate of the sacrificial Cu substrate and the mass transport of noble metal ions. The acceleration of the dissolution of sacrificial substrate increases the reduction rate of noble metal, which develops a steep concentration gradient of noble metal ions near the surface of substrate. This induces the selective deposition of noble metal to form a whisker instead of smooth film. To verify the advantage of whisker-type catalysts, the ethanol oxidation with Pd is investigated. Whisker-type Pd shows 21 times higher electrocatalytic performance than planar Pd due to larger surface area. Therefore, it can be suggested that whisker-type catalysts simply prepared by galvanic displacement is applicable for various electrocatalytic reactions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Pd, Pt, and Au whisker were obtained via one-step galvanic displacement. </LI> <LI> The mechanism of whisker formation was investigated by electrochemical measurements. </LI> <LI> The steep concentration gradient of noble metal ions resulted in the formation of whisker. </LI> <LI> The concentration gradient was controlled by the rates of oxidation and mass transport. </LI> <LI> Pd whisker showed enhanced ethanol oxidation activity compared to planar catalyst. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>