Femtoliter Scale Quantitative Injection Control by Experimental and Theoretical Modeling

유제원,권효성,박항수,홍성회,최연호 대한의용생체공학회 2016 Biomedical Engineering Letters (BMEL) Vol.6 No.4

Purpose Injection is a useful technology for delivery thesolution like drug in medical science, because injectionamount can be simply controlled by adjusting the injectionduration and pressure. With advances in fabrication technology,the small size of syringe can be made from cm to nm scale. Therefore, its application model has been also decreased toa single cell. However, in femto-scale, the precise volumemeasurement and the theoretical estimation by the time andthe pressure becomes very challengeable, because of thedramatic change of inertial forces. In order to estimate thequantitative value of injected volume in femtoliter scale,empirical equation was established as injection pressure,duration and viscosity. Methods We observed the experimental results of theinjected volume in femtoliter scale as a function of viscosity,duration, and pressure. Based on these results, we design andexperimentally verify a theoretical equation for the quantitativecontrol of the volume in femto-scale. The quantitative deliveriesof the injection solution in a living cell were investigated. Results When the external material has viscosity between 80to 12 mPa·s, injection volume is observed to vary between22 to 46 fL. At same conditions, it was observed similaritiesbetween theoretical values and experimental results. Furthermore,fluorescent material was quantitatively injected into aliving single cell. The fluorescent intensity is linearly increasedwith the injection volume. Conclusions It is possible to quantitatively control theinjection volume using the empirical equation in the scaleof femtoliter without any process on coating an injection solution.

Acute and chronic toxicity of flame retardants and antimony on brackish water flea Diaphanosoma celebensis

유제원,박채린,이혜성,이영미 환경독성보건학회 2024 한국독성학회 심포지움 및 학술발표회 Vol.2024 No.5

중금속 복합 노출에 의한 기수산 물벼룩 Diaphanosoma celebensis의 산화적 스트레스에 대한 연구

유제원,조하영,이영미 (사)한국해양생명과학회 2019 (사)한국해양생명과학회 학술대회 Vol.2019 No.10

미세 플라스틱 노출에 의한 기수산 물벼룩 Diaphanosoma celebensis의 산화적 스트레스에 대한 연구

유제원,조하영,전민정,이영미 (사)한국해양생명과학회 2020 (사)한국해양생명과학회 학술대회 Vol.2020 No.06

슈퍼앱 리뷰 토픽모델링을 통한 서비스 강화 방안 연구

유제원,송지훈 한국산업융합학회 2024 한국산업융합학회 논문집 Vol.27 No.2

Super app is an application that provides a variety of services in a unified interface within a single platform. With the acceleration of digital transformation, super apps are becoming more prevalent. This study aims to suggest service enhancement measures by analyzing the user review data before and after the transition to a super app. To this end, user review data from a payment-based super app(Shinhan Play) were collected and studied via topic modeling. Moreover, a matrix for assessing the importance and usefulness of topics is introduced, which relies on the eigenvector centrality of the inter-topic network obtained through topic modeling and the number of review recommendations. This allowed us to identify and categorize topics with high utility and impact. Prior to the transition, the factors contributing to user satisfaction included ‘payment service,’ ‘additional service,’ and ‘improvement.’ Following the transition, user satisfaction was associated with ‘payment service’ and ‘integrated UX.’ Conversely, dissatisfaction factors before the transition encompassed issues related to ‘signup/installation,’ ‘payment error/response,’ ‘security authentication,’ and ‘security error.’ Following the transition, user dissatisfaction arose from concerns regarding ‘update/error response’ and ‘UX/UI.’ The research results are expected to be used as a basis for establishing strategies to strengthen service competitiveness by making super app services more user-oriented.

미세플라스틱 노출에 의한 기수산 물벼룩 Diaphanosoma celebensis 의 산화적 스트레스에 대한 연구

유제원,전민정,조하영,이영미 한국환경생물학회 2020 한국환경생물학회 학술대회 Vol.2020 No.07

비스페놀 A에 대한 기수산 물벼룩의 항산화 시스템의 변화

유제원,차주선,김혜리,표진우,이영미 한국환경생물학회 2019 환경생물 : 환경생물학회지 Vol.37 No.1

Bisphenol A (BPA), a representative endocrine disrupting chemicals, has adverse effects on growth, development and reproduction in aquatic organisms. The object of this study was to investigate the modulation of antioxidant enzyme – coding genes using quantitative real time RT - PCR (qRT - PCR), enzyme activity and total protein content, to understand oxidative stress responses after exposure to BPA for 48 h in brackish water flea Diaphanosoma celebensis. The BPA (3 mg L-1) significantly upregulated the expression of Cu / Zn - SOD, Mn-SOD, and catalase (CAT ) mRNA. Three GST isoforms (GST-kappa, GST-mu, and GST-theta) mRNA levels significantly increased at the rate of 0.12 mg L-1 of BPA. In particular, GST-mu showed the highest expression level, indicating its key role in antioxidant response to BPA. SOD activity was induced with a concentration - dependent manner, and total protein contents was reduced. These findings indicate that BPA can induce oxidative stress in this species, and these antioxidants may be involved in cellular protection against BPA exposure. This study will provide a better understanding of molecular mode of action of BPA toxicity in aquatic organisms. Bisphenol A (BPA)는 대표적인 내분비계장애물질로 수서생물의 성장, 발생, 그리고 생식에 유해한 영향을 주는것으로 알려져 있다. 본 연구는 기수산 물벼룩 (Diaphanosoma celebensis)에서 48시간 BPA 노출 후 산화적 스트레스 반응을 조사하기 위하여 qRT-PCR을 이용한 항산화 유전자 발현 변화, 항산화 효소 활성, 총 단백질 함량 분석을 수행하였다. 3 mg L-1의 BPA에 48시간 노출된 D. celebensis에서 모든 항산화 유전자 (Cu/Zn-SOD, Mn-SOD, CAT)의 발현량이 유의하게 증가하였다. 특히 세 종류의 GST isoforms (GST-kappa, GST-mu, GST-theta)는 가장 낮은 농도인 0.12 mg L-1 BPA에 48시간 노출된 실험군에서도 유의하게 증가하였으며, GST-mu의 발현양이 상대적으로 가장 높게 나타났다. SOD 활성은 BPA 농도에 의존적으로 유의하게 증가하였으며, 총 단백질 함량은 BPA 노출에 대해 감소되는 양상을 보였다. 이러한 결과는 BPA가 D. celebensis에서 산화적 스트레스를 유발하였고, 이 과정에서 이들 항산화 유전자가 생물방어기전으로 참여한다는 것을 의미한다. 본 연구는 BPA가 해양생물에 미치는 영향에 대한 분자적 기전을 이해하는 데 도움이 될 것이다.

금융 슈퍼앱 혁신 유형 분류 및 진화 경로 분석 연구

유제원,송지훈 한국산업융합학회 2024 한국산업융합학회 논문집 Vol.27 No.4

This study aims to classify the types of financial super apps and analyzes their evolution and growth paths by type. Super apps, which provide various services on a single platform, are gaining attention as a key strategy for digital transformation in the financial sector. By adopting the grounded theory methodology, this research has categorized financial super apps into three types: “lifestyle financial super app”, “integrated financial super app”, and “universal financial super app”. Ansoff Matrix was used as a theoretical framework to understand how each type of super app grew and evolved through various strategies. Our analysis revealed that super apps of each type grew using a different mix of ‘market penetration’, ‘product development’, ‘mark et development’, and ‘diversification’ strategies, with each mix showcasing a distinct evolutionary path. The findings of this study are expected to enhance understanding of financial super app typology and evolutionary trajectories, contributing to the development of practical strategies, such as channel optimization for financial super apps in the future.

A stretchable nanowire UV-visible-NIR photodetectors array

유제원,정상화,김성지,제정호 한국고분자학회 2014 한국고분자학회 학술대회 연구논문 초록집 Vol.2014 No.10

벤조피렌과 수은에 대한 기수산 물벼룩 Diaphanosoma celebensis의 복합 독성 영향

유제원,조하영,전민정,이영미,Yoo, Je-Won,Cho, Hayoung,Jeong, Jeon Min,Lee, Young-Mi 한국해양생명과학회 2019 한국해양생명과학회지 Vol.4 No.2

다환방향족탄화수소류(PAHs)는 해양 환경에 오랜 기간 잔류하며 해양 생태계에 유해한 보편적인 환경 오염 물질이다. PAH류는 대부분 해양 환경에서 금속을 비롯한 다양한 오염 물질과 복합적으로 존재하지만 혼합 오염 물질이 개체에 미치는 영향에 대한 연구는 부족하다. 본 연구는 HgCl₂와 Benzo[a]pyrene (B[a]P)이 해양 생물에 미치는 영향을 개체 수준에서 평가하기 위하여 기수산 물벼룩(Diaphanosoma celebensis)을 이용하여 단일 및 혼합 급성 독성 시험을 진행하였다. 혼합 독성 평가에 사용한 혼합물의 농도는 단일 독성 시험을 통하여 얻은 각각의 LC₅₀을 기준으로 3:7 (Mixture A), 5:5 (Mixture B), 7:3 (Mixture C)의 비율로 혼합하여 결정하였다. 실험 결과 B[a]P와 HgCl₂의 48 h - LC₅₀은 각각 25.75 ㎍ l^-1와 3.6 ㎍ l^-1로 나타났다. 혼합 독성 평가 결과 Mixture A, B, C에서 TU는 각각 1.06, 0.83, 0.96로 나타났다. 이는 Mixture A, B, C가 CA 모델에 따라 작용함을 보여주며, HgCl₂와 B[a]P의 상호작용을 연구하기 위해 CA 모델을 사용하는 것이 적합할 것으로 생각된다. 본 연구는 금속과 PAH류의 혼합 독성 평가를 위한 기초 자료가 될 수 있을 것이다. Polycyclic aromatic hydrocarbons (PAHs) are persistent and commonly detected in marine ecosystem. They coexist with a various contaminants including heavy metals in real environment, but most studies have been still focused on single effects of these contaminants to aquatic organisms. In this study, the single and combined effects of benzy[a]pyrene (B[a]P) and HgCl₂ were investigated in the brackish water flea, Diaphanosoma celebensis. For combined effect study, three mixtures A (3:7), B (5:5), and C (7:3) of benzy[a]pyrene (B[a]P) and HgCl₂ were determined by 48 h - LC₅₀ values of single exposure. Combined effects of both chemicals were estimated by concentration addition (CA) model and independent action (IA) model. As results, 48 h - LC₅₀ values of benzy[a]pyrene (B[a]P) and HgCl₂ was 25.75 ㎍ l^-1 and 3.6 ㎍ l^-1, respectively. TU values of mixture A, B, and C were 1.06, 0.83, and 0.96, respectively, indicating additive effects of mixtures using CA model. This study will be helpful as basic data for understanding the combined effects of contaminants in marine environment.