Korean Research Foundation Research Articles

학술도서 출판의 현황과 문제점에 관한 고찰

The purpose of this study is to investigate the status and problems with the Korean academic publishing industry and suggest various countermeasures or alternatives. As a result of searching for the current status of academic book publications to achieve specific research purposes, neither the Korea Publishing Culture Association, which represents the publishing industry in Korea, nor any institution such as the Korea Publication Culture Industry Promotion Agency and the Korean Academy of Sciences are systematically organized to enhance researchers tasks. The current status of academic book publications can only be approximated based on the excellent academic books selected annually by the National Academy of Sciences and the Korea Publication Industry Promotion Agency. In the midst of this, the industry has been in sort of a crisis due to illegal copying of literature, a decrease in the school-age population and the number of users, and online classes. Therefore, the need for a systematic approach/arrangement of the publication statuses of literature is considered imperative. In addition, measures to prevent illegal copying of academic books include conducting related campaigns with increased education concerning this problem and introducing typographical copyright. The budget of the National Research Foundation of Korea for academic publication in the humanities and social sciences need to be expanded to help combat this. Other suggestions include accelerated activities associated with the conversion of academic books to e-books.

Bisphenol-A disturbs hormonal levels and testis mitochondrial activity, reducing male fertility.

How does bisphenol-A (BPA) influence male fertility, and which mechanisms are activated following BPA exposure? BPA exposure causes hormonal disruption and alters mitochondrial dynamics and activity, ultimately leading to decreased male fertility. As public health concerns following BPA exposure are rising globally, there is a need to understand the exact mechanisms of BPA on various diseases. BPA exposure causes hormonal imbalances and affects male fertility by binding the estrogen receptors (ERs), but the mechanism of how it mediates the hormonal dysregulation is yet to be studied. This study consisted of a comparative study using mice that were separated into a control group and a group exposed to the lowest observed adverse effect level (LOAEL) (n = 20 mice/group) after a week of acclimatization to the environment. For this study, the LOAEL established by the US Environmental Protection Agency of 50 mg/kg body weight (BW)/day of BPA was used. The control mice were given corn oil orally. Based on the daily variations in BW, both groups were gavaged every day from 6 to 11 weeks (6-week exposure). Before sampling, mice were stabilized for a week. Then, the testes and spermatozoa of each mouse were collected to investigate the effects of BPA on male fertility. IVF was carried out using the cumulus-oocyte complexes from female hybrid B6D2F1/CrljOri mice (n = 3) between the ages of eight and twelve weeks. Signaling pathways, apoptosis, and mitochondrial activity/dynamics-related proteins were evaluated by western blotting. ELISA was performed to determine the levels of sex hormones (FSH, LH, and testosterone) in serum. Hematoxylin and eosin staining was used to determine the effects of BPA on histological morphology and stage VII/VIII testicular seminiferous epithelium. Blastocyst formation and cleavage development rate were evaluated using IVF. BPA acted by binding to ERs and G protein-coupled receptors and activating the protein kinase A and mitogen-activated protein kinase signaling pathways, leading to aberrant hormone levels and effects on the respiratory chain complex, ATP synthase and protein-related apoptotic pathways in testis mitochondria (P < 0.05). Subsequently, embryo cleavage and blastocyst formation were reduced after the use of affected sperm, and abnormal morphology of seminiferous tubules and stage VII and VIII seminiferous epithelial cells (P < 0.05) was observed. It is noteworthy that histopathological lesions were detected in the testes at the LOAEL dose, even though the mice remained generally healthy and did not exhibit significant changes in BW following BPA exposure. These observations suggest that testicular toxicity is more than a secondary outcome of compromised overall health in the mice due to systemic effects. Not applicable. Since the protein expression levels in the testes were validated, in vitro studies in each testicular cell type (Leydig cells, Sertoli cells, and spermatogonial stem cells) would be required to shed further light on the exact mechanism resulting from BPA exposure. Furthermore, the BPA doses employed in this study significantly exceed the typical human exposure levels in real-life scenarios. Consequently, it is imperative to conduct experiments focusing on the effects of BPA concentrations more in line with daily human exposures to comprehensively assess their impact on testicular toxicity and mitochondrial activity. These findings demonstrate that BPA exposure impacts male fertility by disrupting mitochondrial dynamics and activities in the testes and provides a solid foundation for subsequent investigations into the effects on male reproductive function and fertility following BPA exposure, and the underlying mechanisms responsible for these effects. In addition, these findings suggest that the LOAEL concentration of BPA demonstrates exceptional toxicity, especially when considering its specific impact on the testes and its adverse consequences for male fertility by impairing mitochondrial activity. Therefore, it is plausible to suggest that BPA elicits distinct toxicological responses and mechanistic endpoints based on the particular concentration levels for each target organ. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2018R1A6A1A03025159). No competing interests are declared.

Abstract P340: Codonopsis Lanceolata Extract Prevents Metabolic And Cardiovascular Alterations In Short-term High-fat/high-fructose Diet-fed Adolescent Rats

Fast food consumption, which has increased among adolescents, has been associated with the risk of cardio-metabolic disorders. However, the effects of short-term high-fat/high-fructose diet (HFFD) on cardiovascular and metabolic parameters in adolescent rats has not yet been evaluated. Also, preventive effects of codonopsis lanceolata (CL) in these rats are unknown. Therefore, we investigated the effects of short-term HFFD consumption on cardiovascular and metabolic factors in adolescent rats, as well as the preventive effects of CL extract. Adolescent rats were fed a 60% high-fat diet plus 10% fructose water for 2 weeks. During this time, CL extract (200 or 400 mg/kg) was administered once daily. Short-term HFFD increased visceral white adipose tissue (WAT) weight, fasting blood sugar (FBS) concentration and water intake in adolescent rats. This diet also significantly increased systolic blood pressure (SBP), heart rate, and phenylephrine-induced vasocontraction. CL extract, however, effectively reduced visceral WAT weight, FBS, SBP and heart rate in short-term HFFD-fed adolescent rats. These findings indicate that exposure to HFFD for only 2 weeks induced cardiovascular and metabolic alterations in adolescent rats and that CL extract is effective in preventing these harmful effects of short-term HFFD in adolescent rats. This work was by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2021R1A2C2004118). * Corresponding author. Keywords: high-fat/high-fructose diet; adolescent; codonopsis lanceolata ; prevention; visceral white adipose tissue; fasting blood sugar; systolic blood pressure

A Capacitor-Based Synaptic Device with IGZO Access Transistors for Neuromorphic Computing

IGZO TFT has extremely low leakage current characteristics compared to Si-CMOS, so it can be applied not only to displays but also to various research fields. One of the important applications using IGZO TFT is analog-based synaptic device for the efficient implementation for deep learning. The application of IGZO TFT to a synaptic device was more widely studied after a synaptic device based on Si-CMOS and capacitor was devised in 2017(1). Since insufficient retention time was a remaining problem in Si-CMOS and capacitor-based storage synaptic devices, the combination of IGZO TFT with low leakage current and capacitor was a very attractive solution. However, because the viable p-type metal oxide TFT does not exist, linearity and symmetry of weight update, a major requirement of on-chip trainable synaptic devices, has been difficult to achieve. In our research, for the first time, we obtained linear and symmetric weight update characteristics by combining an IGZO TFT and a capacitor.In addition, we verified the leakage characteristics of IGZO TFT and the retention characteristics of synaptic devices, which are the most important characteristics. Through the single TFT measurement result, we were able to obtain a leakage current per channel width 1µm of 10-17A, which is much smaller than the Si transistor. Lower leakage current will lead to better retention characteristics than conventional Si-CMOS-based devices, which will result in higher accuracy in deep neural network training. Based on the published results, the IGZO TFT synapse is projected to be able to achieve the retention time of ~4×109s using only 10fF capcacitor.Another important factor that affects deep neural network training is cell-to-cell and device-to-device variation. As opposed to capacitive synaptic devices, resistive synaptic devices such as Resistive RAM and Phase Change Memory suffer from large device variation. We also verified the device variation characteristics, which are advantages of charge storage devices based on transistors and capacitors. The variation characteristics of the device were evaluated through the ΔG+3σ/ΔG-3σ(%) formula and an excellent result of ~200% was obtained.In our research, we verified the main characteristics for on-chip training of synaptic devices based on IGZO TFT and capacitor: linearity and symmetry of weight update, retention characteristics and variation characteristics. The remarkable characteristics of synaptic devices based on IGZO TFT and capacitor will be a good candidate for on-chip training.1. S. Kim, T. Gokmen, H. M. Lee, and W. E. Haensch, Midwest Symp. Circuits Syst., 2017-Augus, 422–425 (2017).AcknowledgementsThis research was supported by National R&D Program through the National Research Foundation of Korea(NRF) funded by Ministry of Science and ICT(NRF-2020M3F3A2A01081240)

Electrochemical Reduction of CO2 in Atmospheric Level Using Bimetallic Catalysts on Liquid-Electrolyte Free Cathodic Half Cell

The climate crisis, caused by anthropogenic greenhouse gas (GHG), is one of the most urgent environmental issues. CO2 is one of the GHGs that contributes the most to global warming. Electrochemical CO2 reduction is considered one of the most promising technologies to solve the global warming problem and realize resource recovery. CO2 reduction technology is practically limited because most CO2 reduction techniques are theoretically based on gas-liquid or gas-liquid-solid reactions. Conventional electrochemical CO2 reduction has applied liquid electrolytes, which have the limitation of mass transfer and the problem of liquid product separation. Up to now, most studies have focused on applying high-level CO2 (pure CO2 and % level), which is also practically limited to field application.This study aimed to establish the gas-solid reaction to enable the electrochemical reduction of CO2 at the atmospheric level (hundreds ppm level). We proposed agar gel solid electrolyte inserted between the bimetallic catalysts and ion exchange membranes system for the gas phase CO2 reduction at liquid electrolyte free state. A bimetallic (Cu-Ni or Cu-Zn) metal-organic frameworks (MOFs) used, as electrocatalyst, after coating on 3D foam base. The electrode surface characteristics were confirmed through x-ray diffraction (XRD) and scanning electron microscope (SEM) analysis, and the presence of bimetals on the electrode was confirmed through energy dispersive X-ray spectrometer (EDS). The redox behaviors of the electrode and it’s catalytic CO2 reaction were confirmed through gas-phase cyclic voltammetry and linear sweep voltammetry. It was observed in the experiment that CO2 removal reached up to 99%, and initial product analysis ended with methane, methanol, and dimethyl ether, which will be analyzed and discussed.AcknowledgmentThis research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2021R1I1A1A01049901)

Multilevel Lot-Sizing with Inventory Bounds

We consider a single-item multilevel lot-sizing problem with a serial structure where one of the levels has an inventory capacity (the bottleneck level). We propose a novel dynamic programming algorithm combining Zangwill’s approach for the uncapacitated problem and the basis-path approach for the production capacitated problem. Under reasonable assumptions on the cost parameters the time complexity of the algorithm is [Formula: see text] with L the number of levels in the supply chain and T the length of the planning horizon. Computational tests show that our algorithm is significantly faster than the commercial solver Cplex applied to a standard formulation and can solve reasonably sized instances up to 48 periods and 12 levels in a few minutes. History: Accepted by Andrea Lodi, Area Editor for Design &amp; Analysis of Algorithms–Discrete. Funding: This work was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education [Grant 2014R1A1A2058513].

Admission Control Bias and Path-Dependent Feedback Under Diagnosis Uncertainty

Problem definition: Do physicians exhibit predictable behavioral bias when making admission control decisions under patient diagnosis uncertainty with stochastic arrivals and lengths of stay? How can we structure feedback to help improve their decision making? Methodology/results: We use a behavioral model to theorize how a diagnosis anchoring and insufficient adjustment heuristic may lead to an over-rationing bias, and we hypothesize when this bias is greatest. We then propose that feedback for rejected patients—above and beyond feedback for admitted patients—is critical for mitigating this bias. This is because feedback for only admitted patients may suffer from a type of path dependency that prevents decision makers from receiving the most helpful disconfirming feedback. We provide evidence supporting these hypotheses using preregistered experiments in which medical students, Amazon Mechanical Turk workers, or Prolific workers manage admissions for simulated hospital units. Managerial implications: Our results (1) illuminate an important anchoring bias in admission control under diagnosis uncertainty, (2) identify rejected-patient feedback as a critical component for mitigating this bias, and (3) provide insight into the circumstances under which these phenomena are likely to be most significant. Funding: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) [Grant 2022R1F1A1076045]. Supplemental Material: The online appendix is available at https://doi.org/10.1287/msom.2021.0194 .

Erratum: “Robotic Tensegrity Structure with a Mechanism Mimicking Human Shoulder Motion” [ASME J. Mech. Rob. 14(2), p. 025001; DOI: 10.1115/1.4052124

Abstract The acknowledgment in the publication is incorrect. The correct acknowledgment is given as follows: Acknowledgment This work was supported in part by the National Research Foundation of Korea under Grant No. 2019R1A2C1088375, in part by the Technology Innovation Program funded by the Korean Government (MOTIE) under Grant No. 20008908, and in part by the National Natural Science Foundation of China under Grant No. 62073108.

Tetromino tilings on the Tetris board* *The first author (corresponding author) was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. 2022R1F1A1064273).

Tetrominos, comprised of four identical squares joined together along edges, have achieved substantial popular recognition as the elemental components of the widely known game, Tetris. In this paper, we present a recursive formula aimed at exact enumeration of tetromino tilings on a rectangular board with dimensions m × n. Furthermore, we modify the tiling criterion to mirror the Tetris gameplay, resulting in what we term Tetris tiling of height n. By employing this adjusted condition, we accurately calculate the total number of Tetris tilings. Additionally, the asymptotic behavior of the growth rate associated with the tetromino tiling is discussed.

1512-P: The Novel Roles of Intracellular Calcium and Phosphoinositides in Insulin Signaling and Metabolic Disease

Insulin resistance is closely associated with elevated intracellular Ca2+ concentration under ectopic lipid accumulation and hyperglycemia-induced intracellular stress conditions. We recently identified that obesity impairs intracellular Ca2+ homeostasis, which prevents membrane localization of PH domain-containing proteins such as AKT, PLCδ, and IRS through the formation of Ca2+-phosphoinositides (PIPs), resulting in dysregulation of glucose homeostasis and insulin resistance. It is unclear, however, whether insulin sensitivity can be improved by targeting intracellular Ca2+ overload. Therefore, we screened nine angiotensin-II-receptor blockers (ARBs), a class of antihypertensive agents, for beneficial effects on palmitic acid (PA)-induced insulin resistance in human HepG2 cells. Two of the ARBs attenuated PA-induced intracellular Ca2+ overload by inhibiting dysregulated store-operated channel (SOC)-mediated Ca2+ entry into cells, which ameliorated insulin resistance by promoting insulin-stimulated membrane localization of AKT and by increasing the phosphorylation of AKT and its downstream substrates in PA-treated HepG2 cells. Furthermore, certain ARBs ameliorated obesity-induced insulin resistance, hepatic steatosis, and tissue inflammation in mice fed a high-fat diet. Meanwhile, certain ARBs normalized intracellular Ca2+ homeostasis by regulating obesity-associated SOC-mediated Ca2+ entry, which rescued impaired insulin signaling in liver and muscle tissues by promoting postprandial membrane localization of AKT and IRS2. These findings underscore the contribution of dysregulated intracellular Ca2+ homeostasis to the pathophysiology of insulin resistance and suggest a therapeutic strategy to use specific ARBs to ameliorate insulin resistance. Disclosure J.Lee: None. Y.Jung: None. S.Im: None. D.Lee: None. H.Lee: None. I.Hong: None. O.Kim: None. B.Oh: None. Funding Korean Ministry of Health &amp; Welfare (HI14C1135 to B-C.O.); Basic Science Research Program (2021R1I1A1A01051429 to O-H.K.); Mid-Career Researcher Program (2019R1A2C2008130, 2022R1A2C2092700 to B-C.O.); National Research Foundation of Korea (2021R1A5A203033)

740-P: Six Subclasses with Glucose and Insulin Curves during OGTTs Capture Distinct Metabolic Characteristics and the Most Common Pathway to T2D in a Cohort of Koreans

Heterogeneity of glucose abnormalities makes prevention and treatment of diabetes challenging. Subclasses of people at high risk have been identified based on glucose profiles during OGTTs. However, previous work on subclasses lacks longitudinal confirmation. Here, we used glucose and insulin during OGTTs and k-means clustering to classify subclasses of people without diabetes and then determined the model-derived beta-cell function (BCF) and insulin sensitivity (IS) within each subclass. We identified metabolic risk and the most common pathway to T2D by tracking transitions of subclasses over the 16-year Korean Genome Epi. Study. Participants underwent OGTTs every 2 years for up to 16 years or until diabetes (N=2682, BMI=24.4±2.9 kg/m2, age 49.8±7.6 y). 1) 6 subclasses: Cluster A: Normal BCF, Normal IS, B: Mildly impaired BCF and IS, C: Impaired BCF, mildly impaired IS, D: Strong BCF, impaired IS, E: Mildly impaired BCF, impaired IS, F: Strong BCF, severely impaired IS; 2) Cluster C had the highest risk for T2D, HR: 10.7 (8.0, 14.1), compared to cluster A, followed by Clusters E, B, F, and D; Transition from A to B and C was the most common pathway; A, B, and C together comprised 86% of the cohort. Clustering using glucose and insulin classified 6 subgroups showing distinct metabolic parameters and identified the most common pathway to T2D in Koreans. Disclosure J.Kim: None. H.Kang: None. S.T.Chung: None. A.Sherman: None. S.Kim: None. J.Ha: None. W.Yi: None. D.Kim: None. M.Im: None. S.Ryang: None. M.Kim: None. Y.Kim: None. I.Kim: None. Y.Kim: None. Funding Busan Economic Promotion Agency; National Research Foundation of Korea (2022H1D3A2A01063552); Korea Health Industry Development Institute (HI18C2383); dkNET New Investigator Pilot Program in Bioinformatics; National Institute of Diabetes and Digestive and Kidney Diseases

177-OR: Worsening Insulin Resistance Is Key Pathological Contributor to Dysglycemia in Lean Koreans—A Longitudinal Validation Study in the Korean Genome and Epidemiology Study (KoGES)

Insulin resistance (IR) is a modest but important pathophysiological factor in the development of type 2 diabetes (T2D) in East Asians and manageable through lifestyle intervention. The degree to which worsening insulin resistance independent of beta cell dysfunction, contributes to diabetes progression in lean Koreans is unknown. With a 10-year longitudinal study from a Korean cohort, we investigated whether worsening insulin resistance contributes to disease progression in individuals who had normal glucose tolerance at baseline (N=3700, Age=50.1±8.3 y, BMI= 24.1±2.9 kg/m2). We identified metabolic characteristics of progressors and non-progressors to prediabetes (PreDM) or T2D at baseline and 10 year-longitudinal changes in IR and BMI. To assess whether longitudinal changes of IR, independent of beta-cell function (BCF), contributed to progression, the cohort was divided into low and high BCF groups, using group median at baseline. Progressors to PreDM or T2D had weaker BCF and more insulin resistance, compared to non-progressors (Panel A) at baseline. Insulin sensitivity declined more, 30.7 vs 46.5 vs 16.7% and BMI increased in progressors to PreDM or T2D, but not in nonprogressor (Panels A and B). Conclusion: Worsening insulin resistance even for lean people is a key pathological factor to PreDM and T2D progression. Disclosure D.Kim: None. H.Kang: None. A.Sherman: None. S.T.Chung: None. S.Kim: None. J.Ha: None. J.Kim: None. M.Im: None. S.Ryang: None. W.Yi: None. M.Kim: None. Y.Kim: None. I.Kim: None. Y.Kim: None. Funding Busan Economic Promotion Agency; National Research Foundation of Korea (2022H1D3A2A01063552); Korea Health Industry Development Institute (HI18C2383); dkNET New Investigator Pilot Program in Bioinformatics; National Institute of Diabetes and Digestive and Kidney Diseases

1268-P: One-Hour Glucose Thresholds for T2D Prediction—A Longitudinal Validation Study in the Korean Genome and Epidemiology Study (KoGES)

One-hour glucose to predict prediabetes (PreDM=155mg/dL) and type 2 diabetes (T2D= 209 mg/dl) could improve detection with a shorter 1-hour OGTT, but thresholds need validation in longitudinal cohorts. We determined the risk of incident diabetes using the proposed thresholds with a 16-year longitudinal Korean data set (N=6381, BMI=24±4.0 kg/m2; Age 51.2±8.6 y). OGTT was conducted every 2 y, and 3 groups were assigned at baseline: low one-hour plasma glucose (1h-PG) with normal glucose tolerance (NGT) (low 1h-PG: FPG&amp;lt;100, 2h-PG&amp;lt;140, 1h-PG&amp;lt;155), high 1h-PG with NGT (high 1h-PG: FPG&amp;lt;100, 2h-PG&amp;lt;140, 1h-PG≥155), and PreDM (100≤FPG&amp;lt;126 or 140≤2h-PG&amp;lt;200). Time to T2D was compared by the group in a subset (N=230). T2D risk was higher in high 1h-PG and PreDM than low 1h-PG group (HR:4.9 [3.5, 6.8] and 8.8 [6.5, 11.8]). With the subset of progressors, a linear mixed effect model showed that times to T2D from low and high 1h-PG were 24.8±18.5 y and 19.5±12.4 y (P&amp;lt;0.05). The 1h-PG threshold for T2D, 209 mg/dl, was reached 7.5±14.5 y earlier than the 2h-PG threshold, 200 mg/dl. Conclusion: NGT with high 1h-PG is an intermediate state between low 1h-PG NGT and PreDM, and the 1h-PG threshold for T2D allows earlier diagnosis than the current 2h-PG threshold. Disclosure M.Im: None. I.Kim: None. S.T.Chung: None. A.Sherman: None. J.Ha: None. S.Kim: None. S.Ryang: None. D.Kim: None. W.Yi: None. J.Kim: None. H.Kang: None. Y.Kim: None. Y.Kim: None. M.Kim: None. Funding Busan Economic Promotion Agency; National Research Foundation of Korea (2022H1D3A2A01063552); Korea Health Industry Development Institute (HI18C2383); dkNET New Investigator Pilot Program in Bioinformatics; National Institute of Diabetes and Digestive and Kidney Diseases

국내 집단상담 연구 동향

Objectives The purposes of this study were to find out the recent trends in domestic group counseling research and implications for follow-up studies.&#x0D; Methods The authors searched for the subjects of “group counseling” or “group therapy” from 2011 to 2021 from RISS, selected 695 articles published in the Korean Research Foundation's registered (candidate) journals, and analyzed them according to the analysis frame of Kwon Kyung-in and Jo Su-yeon(2010). The articles were classified into outcome studies of group counseling, process studies, and other studies. Among them, outcome studies were classified into effect studies, studies using meta analysis, and program development studies. The effect studies were classified into total 15 items by adding 4 items(co-leader &amp; observer, Cronbach α, data analysis method, theoretical approach) to 11 items of Kwon Kyung-in and Jo Su-yeon(2010). Process studies were classified into group process-outcome studies, therapeutic factors, case qualitative analysis of group process, outcome prediction from group counselor and client characteristics, and feedback. Finally, other studies were subdivided into overview studies, theoretical studies, and others.&#x0D; Results 604 outcome studies of group counseling, 76 process studies, and 15 other studies were classified. As a significant result of outcome studies, the characteristics of group members were diversified, and studies targeting the elderly, pair, and multicultural characteristics emerged. In the theoretical approach, cognitive behavior theory was the most common, followed by an integrated approach. As a significant result of process studies, studies targeting group counselors and case qualitative analysis of group process were the most common. Finally, in other studies, studies related to group counseling ethics began to appear.&#x0D; Conclusions The authors described the characteristics of group counseling studies developed after the research on group counseling trends of Kim Kay-Hyon(2001), Kwon Kyung-in and Jo Su-yeon(2010). Also the implications for future research were discussed, at the end, the limitations of this study were described.

Early-onset stroke among people with disabilities: a national database study in South Korea from 2008 to 2017

This study investigated 10-year trend in the incidence and prevalence of ischemic, hemorrhagic, and overall strokes according to the severity and type of disability between people with and without disabilities. This serial cross-sectional analysis was conducted using national health information data during a 10-year period from 2008 to 2017. Age-standardized incidence and prevalence were analyzed for each year, according to the presence, severity, and type of disability. The odds ratio (OR) of stroke was examined using multivariable logistic regression after adjusting for socio-demographic and clinical variables collected in2017. In total, 413,398,084 people were enrolled between 2008 and 2017. In 2017, 43,552,192 people aged 19 or older were included and 5.8% was disabled. For 10 years, age-standardized incidence of ischemic and hemorrhagic stroke decreased significantly regardless of the presence of disability. However, age-standardized incidence of stroke in disabled were almost 2.5 times higher than the non-disabled in 2017. Stroke occurs 20 years earlier in people with disabilities than in those without disabilities. In 2017, people with disabilities had higher odds of stroke compared to those without disability (OR=4.11, 95% confidence interval [CI]: 4.06-4.16), particularly among those with severe disabilities (OR=4.75, 95% CI: 4.67-4.84). People with major internal organ impairment showed the highest incidence of stroke (OR=5.95, 95% CI: 5.73-6.17). The main risk factors for stroke presented in this study were disability factors, chronic diseases, and advanced age. People with disabilities are at a greater risk of developing stroke incidence. Developing a public health policy and identifying the risk factors for stroke in people with disabilities would be beneficial. This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Ministry of Education (No. 2022R1I1A3070074).

Behavioral predictors associated with HIV screening needs in gay Korean men during the COVID-19 pandemic.

During the pandemic, the capacity of medical resources focused on testing, diagnosing and treating COVID-19 has severely limited public access to health care. In particular, HIV screening, for which homosexual males in Korea received free and anonymous testing at public health centers, was completely halted. This study investigated behavioral predictors related to the HIV screening needs of Korean male homosexuals during the pandemic. Data were collected by conducting a web survey targeting members of the largest homosexual portal site in Korea with support from the National Research Foundation of Korea (n = 1,005). The key independent variables are COVID-19-related characteristics and sexual risk behavior. The moderating variable is health information search behavior, and the dependent variable is the need for HIV screening. For a statistical analysis, a hierarchical multiple logistic regression analysis was conducted while controlling for potential confounding variables. According to the results of this study, the need for HIV screening was 0.928 times lower for older people (p<0.05, 95% CI = 0.966-0.998). However, if the respondent had a primary partner, the need for HIV screening was 1.459 times higher (p<0.01, 95% CI = 1.071-1.989). In addition, the need for screening was 1.773 times higher for those who preferred anal intercourse (p<0.01, 95% CI = 1.261-2.494) and 2.034 times higher (p<0.01, 95% CI = 1.337-3.095) if there was a history of being diagnosed with an STD. Finally, health information-seeking behavior was marginally significant. This study revealed that male Korean homosexuals who were young, preferred anal sex with a primary partner, and who had a history of a sexually transmitted disease had a high need for HIV screening at public health centers. They are more likely to be susceptible to HIV infection because they are usually consistent with gay men, characterized by risky behavior. Therefore, an intervention strategy that provides health information using a communication campaign is needed.

CLINICAL EFFICACY OF CD34 POSITIVE SELECTION EX‐VIVO PURGING DURING AUTOLOGOUS STEM CELL TRANSPLANTATION IN PERIPHERAL T CELL LYMPHOMA

Background: Autologous stem cell transplantation (ASCT) is the standard treatment for peripheral T-cell lymphomas (PTCLs). Strategies that reduce the relapse rate and treatment-related mortality are essential for successful ASCT. Because in vivo/in vitro purging methods using rituximab are not appropriate for T-cell lymphomas, an ex vivo CD34+ selective purging system using CliniMACS is the most reliable method to reduce autograft tumor cell contamination in these tumors. In the present study, we retrospectively analyzed the clinical outcomes of HDT/ASCT after ex vivo purging via the CD34+ selective method in T-cell NHL patients. Methods: We retrospectively investigated the influence of ex vivo purging with CD34+ selection to maximize the effects of ASCT. Of 67 consecutive PTCL patients, 32 and 35 underwent purged and unpurged ASCT. Results: The purged group had improved overall survival (OS), disease-free survival (DFS), and cumulative incidence of relapse (hazard ratio [HR] = 2.68, p = 0.016; HR = 3.97, p = 0.002; and HR = 3.65, p = 0.004, respectively), compared to the unpurged group. Prognostic factor analysis showed that unpurged ASCT, chromosomal abnormalities at initial diagnosis, high risk, and pre-ASCT disease status were associated with poor survival outcomes. Subgroup analysis demonstrated that purging was most appropriate for International Prognostic Index high-risk patients who underwent upfront ASCT (HR = 3.35 [OS] and = 6.59 [DFS]). In purged ASCT group, NK cell activity and the lymphocyte-to-monocyte ratio known as an independent prognostic factor were increased after ASCT with statistical significance; the lymphocyte-to-monocyte ratio (LMR) was significantly increased after ASCT in the purged group (mean difference = 1.484, 95% CI = 0.407–2.560; p = 0.009). Also, Engraftment was achieved in all patients with no need for unpurged autologous stem cell backup in purged group. There were no engraftment failures or differences in adverse events including of transplant-related viral infections between the two groups. The research was funded by: The research was funded by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2020R1G1A1099654). Keywords: Aggressive T-cell non-Hodgkin lymphoma, Stem Cell Transplant No conflicts of interests pertinent to the abstract.

Myelin‐weighted MR Imaging in Patients with Alzheimer’s Disease

AbstractBackgroundDeveloping an imaging technique to map myelin changes in the brain within a short scan time is needed due to the inability of Alzheimer’s disease (AD) patients to remain motionless during MRI scanning.PurposeTo investigate myelin loss in both AD and mild cognitive impairment (MCI) patients with a new myelin water mapping technique within reasonable scan time and evaluate the clinical relevance of the apparent myelin water fraction (MWF) values by assessing the relationship between decreases in myelin water and the degree of memory decline or aging.MethodIn this prospective study from March 2019 to October 2021, the participants were allocated as follows: 29 individuals were assigned to the cognitively normal (CN) elderly group (mean ± SD, 73 ± 5 years, 16 females), 32 participants were assigned to the MCI group (74 ± 5 years, 21 females), and 31 patients were assigned to the AD group (74 ± 6 years, 26 females). A 3D visualization of the short transverse relaxation time component (ViSTa)‐gradient and spin‐echo (GraSE) sequence was developed to map apparent MWF. Then, the MWF values were compared between the three participant groups, and was evaluated the relationship with the degree of memory loss.ResultA total of 92 participants were evaluated. The AD group showed a reduced apparent MWF compared to the CN and MCI groups. Moreover, the MWF was decreased with age and positively correlated with Mini‐Mental State Examination scores. The largest AUC value (0.799) was in the corpus callosum and used to classify the CN and AD groups using the apparent MWF.ConclusionThe ViSTa‐GraSE sequence can be a useful tool to map the MWF in a reasonable scan time. Combining the MWF in the corpus callosum with the detection of atrophy in the hippocampus can be valuable for group classification.FundingThe research was supported by the National Research Foundation of Korea (NRF) grant funded by Ministry of Science and ICT (No. 2020R1A2C1004749, GHJ), Republic of Korea.

0906 Feasibility of measures of sleep, circadian timing and lipid profiles for identifying mild cognitive impairment

Abstract Introduction Sleep disruption and circadian misalignment has been evident in patients with mild cognitive impairment (MCI). Together, sleep and circadian rhythm dysregulation can contribute to dyslipidemia, which has been proposed to play crucial roles in neurodegenerative process according to its known neurotoxicity. We aimed to compare parameters regarding lipid, nocturnal sleep and circadian timing between amnestic MCI (aMCI) and normal controls (NC), and to determine whether those parameters can be associated with the presence of aMCI in the elderly. Methods Participants above 50 years old were recruited from the Dementia Clinic at Kangwon National University Hospital, and two Public Care Centers for dementia patients. Neurocognitive tests were administered to each participant. The diagnosis of aMCI was made according to Petersen’s criteria. Eighteen aMCI patients (76.6 ±6.1 years) and 21 NC (70.4±6.7years) were finally selected. Actigraphy monitoring (Actiwatch 2; Respironics, USA) was conducted for 5 days. The dim light melatonin onset (DLMO) as an indicator of circadian timing was determined from five hourly saliva samples obtained before sleep onset. Fasting plasma total cholesterol, triglycerides, high density lipoprotein cholesterol, and low density lipoprotein cholesterol were assayed. The sleep parameters, DLMO and lipid profiles were compared between the two groups. For these measures, receiver operating characteristic (ROC) analysis was performed to assess the usefulness of discriminating between the aMCI and NC. Results There were no significant differences in sleep parameters, DLMO and lipid profiles between the aMCI and NC groups. The bedtime and sleep onset were derived as indicators for discriminating aMCI (p=0.003 and p=0.054, respectively). The area under the ROC for bedtime was 0.861(cut-off scores ≥ 22:02, sensitivity= 0.76, specificity=0.75). Conclusion We did not reveal the usefulness of the DLMO and lipid profiles for identifying aMCI. However, we found that the bedtime had good discrimination power between aMCI and cognitively normal elderly, suggesting later sleep habits would be associated with the presence of aMCI in the elderly. Support (if any) Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science and ICT (2020R1F1A1050416); Research Funds from the Institute of Medical Science, Chosun University, Republic of Korea, 2022.

PITX2c impairment electrical remodeling increases susceptibility to atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): the National Research Foundation of Korea (NRF) grants funded by the Korea government (MSIT), the Korean Fund for Regenerative Medicine (KFRM) grant funded by the Korea government Background Functional mutations in the PITX2 (Paired-like homeodomain transcription factor 2) gene cause genetically inherited atrial fibrillation (AF). PITX2 is known to plays a pivotal role in regulating the expression of distinct ion channels, beta-adrenergic stimulation, cell-cell coupling and resulting in AF due to abnormal calcium abnormalities and electrical remodeling. However, the pathophysiological mechanisms linking impaired PITX2 with AF are still to be explored. This study was performed to generate PITX2c knockout human iPSC atrial cardiomyocytes (hiPSC-atrial CM), which are useful tools for arrhythmia modeling, and evaluate the mechanism of PITX2 deficiency leading to AF. Methods We generated a PITX2 knock-out iPSC line using a CRISPR/Cas9-based genome editing system. hiPSCs were electroporated with Cas9/sgRNA ribonucleoprotein (RNP) complexes. PITX2c knock-out hiPSC-CMs differentiated into atrial cardiomyocytes based on the manipulation of retinoic acid signaling. For the three-dimensional (3D) culture model, cells were plated in the spherical plate 5D. Electrophysiological properties and oxidative stress were assessed in PITX2c-deficient cardiomyocytes. Proarrhythmic effects of the PITX2c knock-out were quantified with AP morphology, AP duration (APD) restitution, wavelength (WL) and conduction velocity (CV) restitution using microelectrode arrays (MEA). Results We demonstrated that atrial-specific differentiated hiPSC-CMs expressed atrial-specific genes and the properties of action potentials were like those of human atrial cardiomyocytes. In addition, both 2D and 3D PITX2c knock-out atrial hiPSC-CMs showed signs of APD shortening and reduced wavelength (WL) and increased conduction velocity (CV) restitution (P&amp;lt;0.05). Next, a functional assessment of calcium homeostasis has shown that PITX2c causes atrial arrhythmias by impairing calcium handling genes (SERCA2a, RyR2, PLN). We then demonstrated that miR-374a-5p and miR-374b-5p could be involved in pathophysiological functions as therapeutic candidates when affinity for PITX2 was based on the upper context score percentile (&amp;gt; 99). Conclusions This study provides an understanding of electrical remodeling by PITX2c loss-of-function mutations and suggests the potential therapeutic candidates by miR-374a-5p and miR-374b-5p, thus helping to understand the mechanism of PITX2 deficiency leading to atrial fibrillation.