Identifying pregnancy episodes and estimating the last menstrual period using an administrative database in Korea: an application to patients with systemic lupus erythematosus

Yu-Seon Jung(Yu-Seon Jung),Yeo-Jin Song(Yeo-Jin Song),Jihyun Keum(Jihyun Keum),Ju Won Lee(Ju Won Lee),Eun Jin Jang(Eun Jin Jang),Soo-Kyung Cho(Soo-Kyung Cho),Yoon-Kyoung Sung(Yoon-Kyoung Sung),Sun-You 한국역학회 2024 Epidemiology and Health Vol.46 No.-

Exploring the Relationships Between Emotions and State Motivation in a Video-based Learning Environment

( Jihyun Yu ),( Yunmi Shin ),( Dasom Kim ),( Il-hyun Jo ) 한국교육공학회 2017 Educational Technology International Vol.18 No.2

This study attempted to collect learners’ emotion and state motivation, analyze their inner states, and measure state motivation using a non-self-reported survey. Emotions were measured by learning segment in detailed learning situations, and they were used to indicate total state motivation with prediction power. Emotion was also used to explain state motivation by learning segment. The purpose of this study was to overcome the limitations of video-based learning environments by verifying whether the emotions measured during individual learning segments can be used to indicate the learner’s state motivation. Sixty-eight students participated in a 90-minute to measure their emotions and state motivation, and emotions showed a statistically significant relationship between total state motivation and motivation by learning segment. Although this result is not clear because this was an exploratory study, it is meaningful that this study showed the possibility that emotions during different learning segments can indicate state motivation.

The Effects of Immune Checkpoint Modulators on the Clinical Course of Patients with Resectable Hepatocellular Carcinoma

( Jihyun An ),( Hyo Jeong Kang ),( Ju Hyun Shim ),( Gi-won Song ),( Gwang Hyun Choi ),( Han Chu Lee ),( Bora Oh ),( Naomi Park ),( Jihyun ),( Song Eunsil Yu ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Immune checkpoint proteins regulating T-cell mediated anti-tumor immunity have been reported to affect clinical outcomes in multiple malignancies. This study aimed to investigate the prognostic effect of histological expression of immune checkpoint proteins in patients with resected hepatocellular carcinoma (HCC). Methods: A total of 221 patients with HCC who underwent curative resection were included. Expression of Programmed-cell death ligand- 1 in tumor cells (tPD-L1) and tumor infiltrating mononuclear cells (TIMCs) (iPD-L1), Programmed-cell death-1 in TIMCs (iPD-1), and cytotoxic T lymphocyte antigen-4 in TIMCs (iCTLA-4) were measured immunohistochemically. Results: Among the 221 patients, histo-positivity for iCTLA-4, iPD-1, iPD-L1, and tPD-L1 was 32.1% (n=71), 42.5% (n=94), 35.3% (n=78), and 14.9% (n=33), respectively. Multivariate logistic analyses revealed that male sex and tumor >5cm were variables related to iCTLA-4 positivity (odds ratios [ORs] 0.46 and 1.94 respectively; Ps<0.05). Poor differentiation was related to PD-L1 expression in both tumor cells and TIMCs (ORs 2.88 and 3.46, respectively; Ps<0.05). Microvascular invasion was significantly associated only with iPD-L1, whereas tPD-L1 was positively correlated with baseline elevation of serum alpha-fetoprotein (≥200 ng/ml) (ORs 2.24 and 2.45; Ps<0.05). In time-dependent outcome analyses, expression of immune checkpoint proteins in TIMCs (i.e., iCTLA-4, iPD-1, and iPD-L1) was significantly related to longer overall survival and non-cancer-related survival (all Ps< 0.05), but not to time-to-recurrence or cancer-specific deaths (all Ps >0.05). Concurrent activation of the PD-1:PD-L1 and CTLA-4 pathways predicted improved outcomes in terms of overall survival and non-cancer related survival (P=0.06 and P=0.03, respectively). Conclusions: Immune checkpoint proteins upregulated in TIMCs in HCC tissues have individual and additive effects in prolonging the survival of patients, specifically in terms of survival not related to cancer recurrence.

Review of the Environmental Risk in the Thermal Treatment Process of Dry Active Waste

Jihyun Yu,Byungchae Lee,Jonghoa Kim,Jangsoo Suh 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

Thermal treatment, such as combustion, is the most effective way to solve the spatial problem of radioactive waste disposal. Existing incineration technology has the problem of discharging harmful pollutants (CO2 and dioxin, etc.) into the environment. Therefore, it was evaluate the validity of the thermal treatment process that can reduce the volume of dry active waste (DAW) in an eco-friendly. In addition, the stability of the alternative incineration process under development was evaluated by evaluating the emission of harmful pollutants to the environment during the thermal treatment process. We selected 14 samples identical to those discarded by each nuclear power plant (Kori, Saeul, Wolsong, Hanbit, Hanul). And EA (Elemental Analysis) analysis was performed on each sample. As a result, excluded samples containing wastes containing POPs (Persistent Organic Pollutants) such as PCBs (Polychlorinated Biphenyls), which could generate harmful pollutants during thermal treatment, and halogenated organic wastes such as PVC (Polyvinyl Chloride). In addition, the thermal treatment conditions for the four DAWs were derived by Thermogravimetric Analysis/Differential Thermal Analysis (TG/DTA) analysis. At this time, Py-GC/MS analysis was performed at the temperature at which each waste causes thermal decomposition (cotton is 437°C, paper is 562°C, latex glove is 430°C, plastic bag is 485°C). As a result of analyzing the exhaust gas produced during thermal decomposition, about 77.0% of the cotton was Benzoic acid series, the paper was 41.1% Glucopyranose series, and 15.8% hydroxy acetaldehyde. Latex glove was identified to be 45.9% and 19.2% for Limonene and 2-methyl-1, 3-Butadiene, and for plastic bags, Octacosanol and 2-octyl-1-Dodecanol were 38.8% and 15.2%. In addition, it was confirmed that dioxin and harmful heavy metals, which are discussed as environmental risks, were not detected in all samples.

Comparative Genomic Analysis of Lactobacillus plantarum GB-LP1 Isolated from Traditional Korean Fermented Food

( Jihyun Yu ),( Sojin Ahn ),( Kwondo Kim ),( Kelsey Caetano-anolles ),( Chanho Lee ),( Jungsun Kang ),( Kyungjin Cho ),( Sook Hee Yoon ),( Dae-kyung Kang ),( Heebal Kim ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.8

As probiotics play an important role in maintaining a healthy gut flora environment through antitoxin activity and inhibition of pathogen colonization, they have been of interest to the medical research community for quite some time now. Probiotic bacteria such as Lactobacillus plantarum, which can be found in fermented food, are of particular interest given their easy accessibility. We performed whole-genome sequencing and genomic analysis on a GB-LP1 strain of L. plantarum isolated from Korean traditional fermented food; this strain is well known for its functions in immune response, suppression of pathogen growth, and antitoxin effects. The complete genome sequence of GB-LP1 is a single chromosome of 3,040,388 bp with 2,899 predicted open reading frames. Genomic analysis of GB-LP1 revealed two CRISPR regions and genes showing accelerated evolution, which may have antibiotic and antitoxin functions. The aim of the present study was to predict strain specific-genomic characteristics and assess the potential of this new strain as lactic acid bacteria at the genomic level using in silico analysis. These results provide insight into the L. plantarum species as well as confirm the possibility of its utility as a candidate probiotic.

Temporal and spatial distribution of pH in flow-mode capacitive deionization and membrane capacitive deionization

Yu, Jihyun,Jo, Kyusik,Kim, Taeyoung,Lee, Jiho,Yoon, Jeyong Elsevier 2018 Desalination Vol.439 No.-

<P><B>Abstract</B></P> <P>Capacitive deionization (CDI) is a desalination technique that removes salt from saline water by applying a potential difference between two porous activated carbon electrodes. Although undesirable Faradaic reactions causing a deterioration in the desalination performance in long-term operation have been reported with pH fluctuations and hydrogen peroxide generation, the effect of the temporal and spatial pH distribution and quantitative analysis of charge consumption have rarely been reported or interpreted, especially in membrane capacitive deionization (MCDI). In this study, more detailed and precise investigations were quantitatively conducted to determine the charge consumption for ion adsorption, Faradaic reaction, the co-ion repulsion by analyzing the pH distribution on the electrode surface, the H<SUB>2</SUB>O<SUB>2</SUB> and salt concentration, and the current profiles for short-term and long-term operations of CDI and MCDI. As major results, active Faradaic reactions caused a decrease in the deionization performance in the short-term operation, whereas in the long-term operation of CDI the sustained oxidation of carbon electrode caused its performance to decrease even further. On the other hand, regardless of a short or long term operation, less Faradaic reactions and less oxidation of the carbon electrode were observed with a superior deionization performance in MCDI.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The quantitative charge consumption of (M)CDI was investigated by measuring pH and H<SUB>2</SUB>O<SUB>2</SUB>. </LI> <LI> The charge consumption was analyzed by considering ion adsorption, Faradaic reaction, and co-ion repulsion. </LI> <LI> The CDI charge consumption by co-ion repulsion became severe with time. </LI> <LI> In MCDI, little Faradaic reaction and co-ion repulsion occurred regardless of the operating time. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Case Reports : Drug rash with eosinophilia and systemic symptoms syndrome following cholestatic hepatitis A: a case report

Jihyun An,Joo Ho Lee,Hyojeong Lee,Eun Sil Yu,Dan Bi Lee,Ju Hyun Shim,Sun Young Yoon,Yu Mi Lee,So Eun Park,Han Chu Lee 대한간학회 2012 Clinical and Molecular Hepatology(대한간학회지) Vol.18 No.1

Characteristic Analysis of DAWs to Derive Heat Treatment Process Conditions

Jihyun Yu,Seonghun Kim,Byungchae Lee,Hyerim Kim,Jonghoa Kim,Jangsoo Suh,Younjung Choi 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

Dry active wastes (DAWs) are combustible waste generated during the operation and decommissioning of nuclear facilities, and are known to be generated in the amount of approximately 10,000 to 40,000 drums (based on 200 L) per unit. It consists of various types of protective clothing, paper, and plastic bags, and is stored in radioactive waste storage facilities. Therefore, reducing the volume of DAWs is an important issue in order to reduce storage costs and utilize the limited space of waste storage facilities. Heat treatment such as incineration can dramatically reduce the volume of waste, but as the waste is thermally decomposed, CO2, a global warming gas, is generated and there is a risk of emissions of harmful gases including radionuclides. Therefore, a heat treatment process that minimizes the generation of CO2 and harmful gases is necessary. One of the alternatives to incineration is to carbonize DAWs, dispose of carbonized materials below the release standard as non-radioactive waste, and selectively separate and stabilize inorganic components, including radionuclides, from carbonized DAWs. In this study, 13 types of DAWs generated from nuclear power plants were selected and their thermal decomposition characteristics were investigated to design a heat treatment process that replaces incineration. As a result of TGA analysis, the temperature at which thermal decomposition of each waste begins is 260-300°C for cotton, 320-330°C for paper, 315-420°C for synthetic fiber, 350°C for latex gloves. The mass of most samples decreased to less than 1 % of the initial weight after heat treatment, and dust suit and latex gloves had residues of 13.83% and 13.71% of the initial mass, respectively. The metal components of the residue produced after heat treatment of the sample were analyzed by EDS. According to the EDS results, cotton contains Ca and Al, paper contains Ca, Al and Si, synthetic fiber contains Ca, Cu and Ti, latex gloves contain Ca and Mg. Additionally, ICP analysis was performed to quantify the inorganic components. These results are expected to be applicable to the processing of DAW generated at nuclear facilities in the future.

재취업 산업재해근로자의 일자리 만족을 위한 긍정적 자아개념과 동료 관계에 대한 고찰

유지현(Jihyun Yu),박소연(Soyeon Park),김혜영(Hyeyoung Kim) 한국산학기술학회 2023 한국산학기술학회논문지 Vol.24 No.2

본 연구는 산재보험패널조사 제2차 3차 년도(2020)의 자료를 통해 재취업 산재 근로자의 긍정적 자아개념과 일자리 만족도 간에 동료 관계의 매개 효과를 검증하였다. 조사 대상자 중 재취업자로 응답한 1,130명을 대상으로 분석하였으며, 긍정적 자아개념은 자아존중감과 자기효능감으로 측정하였다. 긍정적 자아개념과 일자리 만족도 간에 동료 관계의 매개 효과를 분석한 결과, 긍정적 자아개념은 일자리 만족도(β=.183, p<.001)와 동료 관계(β=.341, p<.001)에 직접적, 통계적으로 유의한 영향을 미치는 것으로 나타났으며, 동료 관계는 일자리 만족도(β=.434, p<.001)에 직접적인 영향을 유의하게 주는 것으로 나타났다. 긍정적 자아개념이 동료 관계를 통해 일자리 만족도에 영향을 주는지 파악하기 위해 Bootstrapping을 활용하여 간접효과를 검증하였는데, 긍정적 자아개념은 동료 관계를 거쳐 일자리 만족도에 간접적인 영향(β=.148, p<.05)을 미쳤으며, 간접효과가 유의한 것으로 나타났다. 이를 토대로 재취업 산재 근로자의 일자리 만족을 높이기 위해 동료 간의 관계에 주목한 조직 차원의 노력이 필요함을 파악하였다. This study verified the mediating effect of peer relationship on the effect of a positive self-concept on job satisfaction of re-employed industrial workers using data from the second and third years of the Industrial Accident Insurance Panel Survey (2020). The data of 1,130 re-employed individuals that responded to the survey were analyzed, and positive self-concept was measured using self-esteem and self-efficacy. Analysis of the mediating effect of peer relations on positive self-concept and job satisfaction showed that job satisfaction (β=.183, p<.001) and peer relationship (β=.341, p<.001) had a direct and statistically significant effect on positive self-concept, and peer relationship had a significant direct effect on job satisfaction (β=.434, p<.001). The indirect effect of positive self-concept on job satisfaction through peer relationships was verified by bootstrapping (β=.148, p<.05). The study shows organizational efforts directed at the relationship between colleagues are needed to increase job satisfaction among re-employed industrial workers.

Dead Layer Thickness and Geometry Optimization of HPGe Detector Based on Monte Carlo Simulation

Suah Yu,Na Hye Kwon,Young Jae Jang,Byungchae Lee,Jihyun Yu,Dong-Wook Kim,Gyu-Seok Cho,Kum-Bae Kim,Geun Beom Kim,Cheol Ha Baek,Sang Hyoun Choi Korean Society of Medical Physics 2022 의학물리 Vol.33 No.4

Purpose: A full-energy-peak (FEP) efficiency correction is required through a Monte Carlo simulation for accurate radioactivity measurement, considering the geometrical characteristics of the detector and the sample. However, a relative deviation (RD) occurs between the measurement and calculation efficiencies when modeling using the data provided by the manufacturers due to the randomly generated dead layer. This study aims to optimize the structure of the detector by determining the dead layer thickness based on Monte Carlo simulation. Methods: The high-purity germanium (HPGe) detector used in this study was a coaxial p-type GC2518 model, and a certified reference material (CRM) was used to measure the FEP efficiency. Using the MC N-Particle Transport Code (MCNP) code, the FEP efficiency was calculated by increasing the thickness of the outer and inner dead layer in proportion to the thickness of the electrode. Results: As the thickness of the outer and inner dead layer increased by 0.1 mm and 0.1 ㎛, the efficiency difference decreased by 2.43% on average up to 1.0 mm and 1.0 ㎛ and increased by 1.86% thereafter. Therefore, the structure of the detector was optimized by determining 1.0 mm and 1.0 ㎛ as thickness of the dead layer. Conclusions: The effect of the dead layer on the FEP efficiency was evaluated, and an excellent agreement between the measured and calculated efficiencies was confirmed with RDs of less than 4%. It suggests that the optimized HPGe detector can be used to measure the accurate radioactivity using in dismantling and disposing medical linear accelerators.