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We describe the collective behavior of isotropic droplets dispersed over a spherical smectic bubble, observed under microgravity conditions on the International Space Station (ISS). We find that droplets can form two-dimensional hexagonal structures changing with time. Our analysis indicates the possibility of spatial and temporal periodicity of such structures of droplets. Quantitative analysis of the hexagonal structure including the first three coordination circles was performed. A peculiar periodic-in-time ordering of the droplets, related to one-dimensional motion of droplets with non-uniform velocity, was found.

Sleep is being emphasized as a factor that improves mental health and quality of life. Here, we aimed to investigate the association between the quality and duration of sleep and subjective cognitive decline in the Korean population. We used the 2018 Korean Community Health Survey data that are nationwide representative data collected by the Korea Centers for Disease Control and Prevention. Sleep quality was measured using the Korean version of Pittsburgh Sleep Quality Index. The study population comprised 206,719 individuals aged 19 years and over. We used multiple logistic regression for the analysis. Individuals of both sexes with poor sleep quality were more likely to experience subjective cognitive decline compared with the reference group (good sleep quality) (men, odds ratio (OR) = 1.97 [95% confidence interval (CI) 1.86–2.09]; women, OR = 1.75 [95% CI 1.67–1.84]). U-shape associations were found between sleep duration and subjective cognitive decline. Additionally, the presence of depressive symptom or stress and health-related behaviors, including smoking, drinking, and not walking, were high-risk factors for subjective cognitive decline. Our results indicate that poor sleep quality might contribute to subjective cognitive decline in the Korean population. We suggest the implementation of intervention measures for poor sleep behaviors to prevent cognitive decline.

To evaluate the implication of 18F-fluorodeoxyglucose (FDG)- and dopamine transporter (DAT)-positron emission tomography (PET) in the diagnosis and clinical symptoms of dementia with Lewy bodies (DLB), 55 DLB patients and 49 controls underwent neuropsychological evaluation and FDG-, DAT-, and 18F-Florbetaben (FBB) PET. DAT- and FDG-uptake and FDG/DAT ratio were measured in the anterior and posterior striatum. The first principal component (PC1) of FDG subject residual profiles was identified for each subject. Receiver operating characteristic curve analyses for the diagnosis of DLB were performed using FDG- and DAT-PET biomarkers as predictors, and general linear models for motor severity and cognitive scores were performed adding FBB standardized uptake value ratio as a predictor. Increased metabolism in the bilateral putamen, vermis, and somato-motor cortices, which characterized PC1, was observed in the DLB group, compared to the control group. A combination of posterior putamen FDG/DAT ratio and PC1 showed the highest diagnostic accuracy (91.8% sensitivity and 96.4% specificity), which was significantly greater than that obtained by DAT uptake alone. Striatal DAT uptake and PC1 independently contributed to motor severity and language, memory, frontal/executive, and general cognitive dysfunction in DLB patients, while only PC1 contributed to attention and visuospatial dysfunction.

Concomitant percutaneous transluminal angioplasty (PTA) at the time of percutaneous coronary intervention (PCI) is often performed because lower extremity artery disease (LEAD) commonly coincides with coronary artery disease. We investigated the impact of concomitant PTA on both cardiovascular and limb outcomes in the Korean National Health Insurance Service registry. Among 78,185 patients undergoing PCI, 6563 patients with stable LEAD without limb ischemia were included. After 1:5 propensity score matching was conducted, 279 patients in the PTA + PCI group and 1385 patients in the PCI group were compared. Multivariate Cox proportional hazard models showed that the risk of all-cause death was higher in the PTA + PCI group than in the PCI group, whereas the risks of myocardial infarction, repeat revascularization, stroke, cardiovascular death and bleeding events were not different between the 2 groups. In contrast, the risks of end-stage renal disease and unfavorable limb outcomes were higher in the PTA + PCI group. Mediation analyses revealed that amputation and PTA after discharge significantly mediated the association between concomitant PTA and all-cause death. Concomitant PTA was not associated with an increased risk of cardiovascular events but may increase the risk of all-cause death mediated by unfavorable renal and limb outcomes in patients with stable LEAD.

Children are at risk of exposure to secondhand smoke. We aimed to evaluate the extent of their exposure to it in relation to their parents’ smoking status by using biomarkers relevant to smoking. We evaluated 847 school-age children (6–12 years) who lived with their parents, using data from the Korea National Health and Nutrition Examination Survey 2016–2018. Secondhand smoke exposure in children of non-smoking and smoking parents was assessed by measuring urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and cotinine concentrations. Overall, the parents of 482 (55.1%) children smoked and those of 392 (44.9%) children did not smoke. After adjusting for covariates, significantly higher concentrations of NNAL (β = 0.482, standard error [S.E.] = 0.065, P

The purpose of this research was to identify metabolite change during barley (Hordeum vulgare) germination and reveal active principles for the anti-wrinkle activity. Barley was germinated with deionized water (DW) and mineral-rich water (MRW) for the comparison of the effect of mineral contents on the metabolites changes during germination. The effects of germinated barley extracts (GBEs) on collagen production and collagenase inhibition were evaluated in vitro using human dermal fibroblasts (HDFs). A pronounced anti-wrinkle activity was observed in the test group treated with the MRW-GBEs. In order to find out the active components related to the anti-wrinkle activity, an orthogonal projection to latent structure-discriminant analysis (OPLS-DA) was performed, using the data from secondary metabolites profiling conducted by UPLC–PDA–ESI–MS. The anti-wrinkle activity of MRW-GBEs was revealed to be associated with the increase of oligomeric compounds of procyanidin and prodelphinidin, indicating that it can be used as an active ingredient for anti-wrinkle agents.

Kidney disease is expected to become the fifth leading cause of premature death globally by 2040. Uric acid level is a risk factor for kidney disease. The current study aims to investigate the association between uric acid levels and kidney function in the Korean population. The data of 11,042 participants of the 2016–2017 Korea National Health and Nutrition Examination Survey were analysed. The estimated glomerular filtration rate was calculated using the modification of diet in renal disease formula for Koreans. For each sex, uric acid levels were divided into five subsequent categories of increasing levels (Q1, Q2, Q3, Q4, and hyperuricemia). The association between uric acid level and kidney function was investigated using multiple logistic regression. The results showed that the higher the uric acid levels, the greater the odds of reduced kidney function in both sexes. In men, the adjusted odds ratios (95% confidence intervals) for reduced eGFR comparing the hyperuricemia group to the lowest serum uric acid quartile was 5.55 (3.27–9.44), and in women, the odds ratios (95% confidence intervals) was 7.52 (4.39–12.87). Normal weight or underweight in men and overweight in women, as well as diabetes mellitus, hypertension, and physical inactivity were highly associated with reduced kidney function. Our study revealed a dose–response relationship between uric acid levels and kidney function. Therefore, high uric acid level should be considered as a factor that is potentially related to kidney dysfunction in the Korean population.

The severity of the coronavirus disease (COVID-19) is associated with various comorbidities. However, no studies have yet demonstrated the potential risk of respiratory failure and mortality in COVID-19 patients with pre-existing asthma. We selected 7272 adult COVID-19 patients from the Korean Health Insurance Review and Assessment COVID-19 database for this nationwide retrospective cohort study. Among these, 686 patients with asthma were assessed by their severities and evaluated by the clinical outcome of COVID-19 compared to patients without asthma. Of 7272 adult COVID-19 patients, 686 with asthma and 6586 without asthma were compared. Asthma was not a significant risk factor for respiratory failure or mortality among all COVID-19 patients (odds ratio [OR] = 0.99, P = 0.997 and OR = 1.06, P = 0.759) after adjusting for age, sex, and the Charlson comorbidity score. However, a history of acute exacerbation (OR = 2.63, P = 0.043) was significant risk factors for death among COVID-19 patients with asthma. Asthma is not a risk factor for poor prognosis of COVID-19. However, asthma patients who had any experience of acute exacerbation in the previous year before COVID-19 showed higher COVID-19-related mortality, especially in case of old age and male sex.

With nearly 10% of women consuming alcohol during pregnancy, fetal alcohol spectrum disorders (FASDs) are becoming an increasing concern for clinicians and policymakers interested in the field of healthcare. Known as the range of mental and/or physical disabilities that occur among individuals with prenatal alcohol exposure, FASDs can result in dysmorphic features, problems with physical growth, neurobehavioral and cognitive problems that not only increase risk of various diseases, but also premature mortality. We investigated whether the diagnosis of FASDs result in increased risk of hospitalizations and mortality, with respect to FASD domains and relative diseases, when age effects are controlled for. The data for this study was taken from the National Health Insurance Service – National Sample Cohort (NHIS-NSC) between 2003 and 2013. The population attributable risk (PAR) statistic was used to estimate the percentage of hospitalizations and mortality attributable to FASDs and other factors. A time-dependent Cox proportional hazards model with age of diagnosis as the time-scale was employed to calculate adjusted hazard ratios and 95% CIs for hospitalizations and mortality among FASD populations compared to their general population peers. Among the 3,103 FASD cases, 27.5% experienced hospitalizations and 12.5% died. Overall, FASDs accounted for 853 FASD-attributable hospitalizations (51.0% of all hospitalizations in the study population) and 387 mortality events (34.5% of all deaths in the study population). 20.52% of hospitalizations and 21.35% of mortalities were attributable to FASDs in this population. Compared to the control group, FASD patients had a 1.25-fold (HR: 1.25, 95% CI: 1.05–1.49, p = 0.0114) increased risk of hospitalizations and a 1.33-fold (HR: 1.33, 95% CI: 1.07–1.67, p = 0.0118) increased risk of all-cause mortality. The most common cause for hospitalization was diseases of the nervous system, which accounted for 450 FASD-attributable hospitalizations (96.2% of all nervous system hospitalizations in the study population). In fact, FASD patients were 52 times more likely to be hospitalized for nervous system diseases than their peers (HR: 51.78, 95% CI: 29.09–92.17, p Trial Registration: Institutional Review Board of Yonsei University’s Health System: Y-2019-0174.

Although large exciton binding energies of typically 0.6–1.0 eV are observed for monolayer transition metal dichalcogenides (TMDs) owing to strong Coulomb interaction, multilayered TMDs yield relatively low exciton binding energies owing to increased dielectric screening. Recently, the ideal carrier-multiplication threshold energy of twice the bandgap has been realized in multilayered semiconducting 2H-MoTe2 with a conversion efficiency of 99%, which suggests strong Coulomb interaction. However, the origin of strong Coulomb interaction in multilayered 2H-MoTe2, including the exciton binding energy, has not been elucidated to date. In this study, unusually large exciton binding energy is observed through optical spectroscopy conducted on CVD-grown 2H-MoTe2. To extract exciton binding energy, the optical conductivity is fitted using the Lorentz model to describe the exciton peaks and the Tauc–Lorentz model to describe the indirect and direct bandgaps. The exciton binding energy of 4 nm thick multilayered 2H-MoTe2 is approximately 300 meV, which is unusually large by one order of magnitude when compared with other multilayered TMD semiconductors such as 2H-MoS2 or 2H-MoSe2. This finding is interpreted in terms of small exciton radius based on the 2D Rydberg model. The exciton radius of multilayered 2H-MoTe2 resembles that of monolayer 2H-MoTe2, whereas those of multilayered 2H-MoS2 and 2H-MoSe2 are large when compared with monolayer 2H-MoS2 and 2H-MoSe2. From the large exciton binding energy in multilayered 2H-MoTe2, it is expected to realize the future applications such as room-temperature and high-temperature polariton lasing.

We investigated the association between working status changes and hand-grip strength (HGS) among middle-aged and older Korean adults using data from the 2006–2018 Korean Longitudinal Study of Aging. After excluding those with less than normal HGS in the baseline year, newly added panels, and missing values, 3843 participants (2106 men; 1737 women) were finally included. After adjusting for potential confounders, we used a 2-year lagged multivariable generalized estimating equation model to examine this association longitudinally. Men who quit working or who continued to be non-working were more likely to have lower HGS than those who continued to work (working → non-working, adjusted odds ratio [OR]: 1.47, 95% confidence interval [CI] 1.26–1.70; non-working → non-working, adjusted OR: 1.52, 95% CI 1.34–1.72). Compared to women who continued to work, the other three groups showed high ORs with low HGS (working → non-working, adjusted OR: 1.19, 95% CI 1.01–1.40; non-working → working, adjusted OR: 1.18, 95% CI 0.98–1.42; non-working → non-working, adjusted OR: 1.38, 95% CI 1.22–1.56). Middle-aged and older adults whose working status changed to non-working were at higher risk of reduced HGS than others and required muscular strength training interventions to improve HGS and prevent sarcopenia.

Home blood pressure (HBP) is useful to decide whether blood pressure (BP) is controlled. However, applying HBP to daily clinical practices is still challenging without easy access to the average HBP. Therefore, we developed a simple method to make a quick decision regarding the controlledness of HBP through high BP counts. We simulated 100 cases of HBP series for each combination of 3 numbers of BP readings (K = 16, 20, 24) and 4 levels of the standard deviations (SDs = 5, 10, 15, 20). A high BP was defined as an individual BP ≥ 135/85 mmHg, and an uncontrolled HBP was defined as a mean HBP ≥ 135/85 mmHg. Validation for the decision method was conducted using actual HBP data. The C-statistics and the accuracy of the high BP counts for the uncontrolled HBP were generally high (> 0.85) for all combinations of Ks and SDs and decreased as SDs increased but remained steady as Ks increased. In validation, the C-statistic of the high BP count-to-total BP reading (C/T) ratio was 0.985, and the C/T ratio ≥ 0.5 showed a sensitivity of 0.957, a specificity of 0.907, and an accuracy of 0.927. The count-based decision method can provide an accurate quick assessment of the controlledness of HBP.

The evidence for the impact of benzodiazepine (BZD) use on infection or clinical outcomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is limited. We evaluated the association of BZD use with SARS-CoV-2 infection and the clinical outcomes of coronavirus disease 2019 (COVID-19) using a nationwide COVID-19 database from South Korea. This nationwide cohort study was performed using the COVID-19 database from the Health Insurance Review and Assessment Service of Korea, and SARS-CoV-2 positivity was investigated according to BZD use. SARS-CoV-2-positive adult patients were assessed in three groups, those who needed hospitalization, those with severe symptoms requiring intensive care, and those who died. A multivariate logistic regression model was used for all the analyses. After adjusting for potential confounding factors, there was no association between BZD use and SARS-CoV-2 positivity. SARS-CoV-2-positive patients with BZD use showed an increased risk of need for hospitalization from COVID-19 compared to those without BZD use (odds ratio [OR]: 1.33, 95% confidence interval [CI] 1.07–1.65). In addition, there was a higher risk for long-term users (OR: 2.64, 95% CI 1.08–6.47). Chronic BZD use contributed to a higher risk of the need for hospitalization among COVID-19 patients, whereas BZD use did not increase the risk of SARS-CoV-2 test positivity, severe outcomes, or mortality.

Epidemiological evidence has indicated that inflammatory markers and obesity are strongly correlated with insulin resistance (IR). However, there is a paucity of studies assessing the complex interaction between elevated hs-CRP and body mass index (BMI), particularly among Asians. This study investigated the additive interaction between hs-CRP and BMI on IR, using cross-sectional data from the 7th Korea National Health and Nutrition Examination Survey (2016–2018). A total of 5706 men and 6707 women aged 20 years or older were evaluated, and a multiple logistic regression analysis was used to assess the association of serum hs-CRP and BMI with IR, as measured by the triglyceride-glucose index (TyG index). Sex-specific median values were used to dichotomise the continuous TyG index variable into insulin-sensitive and IR categories. Biological interaction was evaluated using the Relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (SI). The joint effects of high hs-CRP and overweight/obesity on IR were greater than would be expected from the effects of the individual exposures alone. Relative to those with low hs-CRP and BMI

We propose an all-dielectric quasi-one-port resonance structure that achieves near perfect absorption without the use of a back mirror. The structure mainly consists of a high-refractive-index silicon metasurface and surrounding high-refractive-index guiding layers. The dual-guiding-layer (DGL) structure has high background reflectance and is designed to have a ratio of two decay rates into the upper and lower regions within a wider range. When an absorbing material is introduced into a DGL system, it can be designed to achieve a near critical-coupling condition by reducing the constraints in the two decay rates. By using single-layer graphene as an absorbing material, the DGL resonance structure shows an absorption of ~ 97% and a phase change of ∼ 0.95π near the wavelength of 1550 nm, confirming quasi-critical coupling. The optimized DGL structure is relatively insensitive to potential fabrication imperfections, and consequently, the expected average peak wavelength and absorption are obtained as 1549.29 nm and 96.74%, respectively. Angle-dependent absorption confirms that maximum absorption occurs under normal incidence. The DGL absorber is also designed to cover the whole C-band region, in order to meet the quasi-critical-coupling condition. All mode profiles are similarly quasi-symmetric along the metasurface due to the same DGL resonance mechanism.

2′-Fucosyllactose (2′-FL), a major component of fucosylated human milk oligosaccharides, is beneficial to human health in various ways like prebiotic effect, protection from pathogens, anti-inflammatory activity and reduction of the risk of neurodegeneration. Here, a whole-cell fluorescence biosensor for 2′-FL was developed. Escherichia coli (E. coli) was engineered to catalyse the cleavage of 2′-FL into l-fucose and lactose by constitutively expressing α-l-fucosidase. Escherichia coli ∆L YA, in which lacZ is deleted and lacY is retained, was employed to disable lactose consumption. E. coli ∆L YA constitutively co-expressing α-l-fucosidase and a red fluorescence protein (RFP) exhibited increased fluorescence intensity in media containing 2′-FL. However, the presence of 50 g/L lactose reduced the RFP intensity due to lactose-induced cytotoxicity. Preadaptation of bacterial strains to fucose alleviated growth hindrance by lactose and partially recovered the fluorescence intensity. The fluorescence intensity of the cell was linearly proportional to 1–5 g/L 2′-FL. The whole-cell sensor will be versatile in developing a 2′-FL detection system.

Circadian misalignment caused by differences in sleep duration between weekends and weekdays may be associated with adolescent mental health and sleep quality may be able to compensate for this problem. This study aimed to investigate the association between weekend catch-up sleep (CUS) ratio and sleep quality with depressive symptoms and suicidal ideation among South Korean adolescents. We used data from the Korea Youth Risk Behavior Web-based Survey 2015–2019 involving 270,619 adolescents. The weekend CUS ratio was calculated by dividing the average weekend sleep duration by the average weekday sleep duration (

This study aimed to determine whether significant associations exist between multicultural families and adolescent smoking risks in South Korea. Data from the Korea Youth Risk Behavior Web-based survey from 2016 to 2020 were analyzed. Participants were classified into four family types (South Korean mother–foreign father, South Korean father–foreign mother, both foreign parents, and both South Korean parents) according to their parents’ country of birth and smoking was assessed using a self-reported questionnaire. A logistic regression analysis was used to examine the significance of the associations. Overall, 194,259 participants (boys: 94,793, girls: 99,466) enrolled in this study. Adolescents whose parents were born overseas were more likely to smoke than native South Korean adolescents (boys: odds ratio [OR] = 2.61, confidence interval [CI] = 1.79–3.81, girls: OR 3.94, CI 2.42–6.43). When the mother’s country of birth was a developing country, there was an increased likelihood of girls smoking, and there was an increased likelihood of smoking among boys when the mother’s country of birth was North Korea. When both parents were born abroad, and the mother’s country of birth was a developing country, the likelihood of smoking risks among their multicultural teenage children increased. Policies and interventions need to be established and implemented to lower the smoking rate among multicultural teenagers.

In this cohort study, we assessed the association between depression and the risk of Alzheimer’s disease from data obtained from the 2002 to 2013 Korean National Health Insurance Service-Elderly Cohort Database, which accounts for 10% of the South Korean population aged > 60 years. A total 518,466 patients were included in the analysis and followed up, unless they were excluded due to death or migration. Patients who sought treatment for depression or dementia within 1 year of the washout period and who were diagnosed with dementia within the 1-year period of the diagnosis of depression were excluded from the study. The risk of dementia was analysed using Cox proportional hazards models. Patients with a history of depression during the follow-up period were at a higher risk of Alzheimer’s disease than those without a history of depression (HR 3.35, CI 3.27–3.42). The severe-depression group exhibited the highest risk of Alzheimer’s disease (HR 4.41, CI 4.04–4.81), while the mild-depression group exhibited a relatively lower risk of Alzheimer’s disease (HR 3.31, CI 3.16–3.47). The risk of Alzheimer’s disease was associated with depression history and an increased severity of depression increased the risk of Alzheimer’s disease.

Perfect absorption at a resonance wavelength and extremely low absorption at the wavelength range of off-resonance in a one-port optical cavity is required for refractive index (RI) sensing with high signal contrast. Here, we propose and analyze an absorption-enhanced Fabry–Perot (MAFP) cavity based on a critical coupling condition in a near-infrared wavelength range. For a one-port cavity, a thick bottom Au is used as a mirror and an absorber. To achieve the critical coupling condition, a top dielectric metasurface is employed and tailored to balance the radiation coupling and the absorption coupling rates, and the one-port cavity is theoretically analyzed using temporal coupled-mode theory. We investigate two types of MAFP structures for gas and liquid. The gas MAFP cavity shows a sensitivity of ~ 1388 nm/RIU and a full-width at half-maximum of less than 0.7 nm. This MAFP cavity resolves the RI change of 5 × 10−4 with a reflectance signal margin of 50% and achieves a signal contrast of ~ 100%. The liquid MAFP cavity shows a sensitivity of ~ 996 nm/RIU when RI of liquid changes from 1.30 to 1.38. With tailoring the period of the metasurface maintaining its thickness, a signal contrast of ~ 100% is achieved for each specific RI range.

Although large exciton binding energies of typically 0.6-1.0 eV are observed for monolayer transition metal dichalcogenides (TMDs) owing to strong Coulomb interaction, multilayered TMDs yield relatively low exciton binding energies owing to increased dielectric screening. Recently, the ideal carrier-multiplication threshold energy of twice the bandgap has been realized in multilayered semiconducting 2H-MoTe

Smoking cessation aids in restoring lung function. However, whether long-term cessation can fully restore lung function has not been studied thoroughly, especially in Asian countries. This study aimed to evaluate the association between smoking cessation status and obstructive spirometry pattern among Koreans aged 40–79 years. In total, 6298 men and 8088 women aged 40–79 years from the Korea National Health and Nutrition Examination Survey (2015–2019) were analyzed for smoking cessation status, including the duration after quitting. Current-smokers showed a higher likelihood of having an obstructive spirometry pattern than never-smokers among both men (odds ratio [OR]: 3.15, 95% confidence interval [CI]: 2.32–4.29) and women (OR: 2.60, 95% CI: 1.59–4.23). In men, the effect tended to decrease with longer duration after cessation, but male ex-smokers who had quit smoking ≥ 20 years ago still showed a higher likelihood of having an obstructive spirometry pattern than male never-smokers (OR: 1.40, 95% CI: 1.05–1.89). In female ex-smokers, there was no significant association with the obstructive spirometry pattern, compared to that in female never-smokers. This study emphasizes the benefits of smoking cessation, possibility of long-lasting harm to lung function due to tobacco smoking, and importance of smoking prevention.

Recent studies suggest that sensory impairment is related to cognitive function at older ages. Therefore, we aimed to investigate the impact of sensory impairment on cognitive function in the Korean population. We used the Korean Longitudinal Study of Aging data from 2006 to 2018. Cognitive function was measured by the Korean version of the Mini-Mental State Examination scale. A score

Adaptive radiation is a phenomenon in which various organs are diversified morphologically or functionally as animals adapt to environmental inputs. Leeches exhibit a variety of ingestion behaviors and morphologically diverse ingestion organs. In this study, we investigated the correlation between behavioral pattern and feeding organ structure of leech species. Among them, we found that Alboglossiphonia sp. swallows prey whole using its proboscis, whereas other leeches exhibit typical fluid-sucking behavior. To address whether the different feeding behaviors are intrinsic, we investigated the behavioral patterns and muscle arrangements in the earlier developmental stage of glossiphoniid leeches. Juvenile Glossiphoniidae including the Alboglossiphonia sp. exhibit the fluid ingestion behavior and have the proboscis with the compartmentalized muscle layers. This study provides the characteristics of leeches with specific ingestion behaviors, and a comparison of structural differences that serves as the first evidence of the proboscis diversification.

Frailty is considered a multidimensional geriatric syndrome, manifested by the accumulation of age-associated deficits. The consequences of frailty transitions are still understudied. This study evaluated the influence of frailty transitions on cognitive function in the older adult population. We used data derived from the Korean Longitudinal Study of Aging (KLoSA) (2008–2018) on older adults aged ≥ 65 years. Frailty was assessed using a validated Korean frailty measure known as the frailty instrument (FI), and cognitive function was measured using the Korean version of the Mini-Mental State Examination (K-MMSE). Transitions in frailty and their relationship with cognitive function were investigated using lagged generalized estimating equations (GEE), t-tests, and ANOVA. Respondents who experienced frailty transitions (those with ameliorating frailty), those who developed frailty, and whose frailty remained constant, were more likely to have a lower cognitive function than those who were consistently non-frail. Older age, activities of daily living (ADL) disability, and instrumental ADL disability were more negatively associated with declining cognitive function, especially in the “frail → frail” group. Changes in all individual components of the frailty instrument were significantly associated with impaired cognitive function. The results suggest an association between frailty transitions and cognitive impairment. Over a 2-year span, the remaining frail individuals had the highest rate of cognitive decline in men, while the change from non-frail to frail state in women was significantly associated with the lowest cognitive function values. We recommend early interventions and prevention strategies in older adults to help ameliorate or slow down both frailty and cognitive function decline.

While physical activity (PA) may influence resting heart rate (RHR), and a low RHR may be a risk factor for atrial fibrillation (AF), controversy exists regarding the association between PA and development of AF. Using data from a Korean, prospective population cohort, we investigated the independent effect of PA and RHR on the incidence of AF in the general population. A total of 8,811 participants aged 40–69 years were analyzed. Total PA assessed based on questionnaires was divided into quartiles, with the lowest to the highest being Q1, Q2, Q3, and Q4. During a median follow-up of 139 months, AF developed in 167 participants (1.9%). Q3 of total PA was associated with a significantly lower risk of AF than Q1 even after adjusting for RHR as a covariate, but Q4 was not. The risk of AF was higher in participants with RHR

This study investigated the association between depressive symptoms and cognitive function according to four different trajectories of depressive symptoms in the late middle-aged and older South Korean population. Panel data from the Korean Longitudinal Study of Ageing were analyzed. We used latent class trajectory models to identify four trajectories of depressive symptoms. We performed linear mixed-effects regression analysis to assess associations between depressive-symptom trajectories and MMSE scores. Of 4,374 participants, 18.4%, 4.9%, 55.2%, and 21.5% were classified as having a low, increasing, moderate declining, and high depressive-symptom trajectory, respectively. Individuals with an increasing trajectory (β = −0.729, P ≤ 0.001), moderate trajectory (β = −0.278, P = 0.003), and high trajectory (β = −1.605, P ≤ 0.001) had lower MMSE scores compared with those in the low trajectory group. These relationships were particularly strong among women; individuals who were physically inactive; those who were separated, divorced, or single; and those with hypertension or cerebrovascular disease. Each trajectory group for depressive symptoms was associated with cognitive decline. Moreover, female, physically inactive, and single individuals, as well as those with hypertension and cerebrovascular disease should be particularly mindful of their mental and physical health to prevent cognitive decline.

Elevated levels of circulating high-sensitivity C-reactive protein (hs-CRP) have been observed in depression, with the body mass index (BMI) being a major mediator of this association. However, the sex difference in the association between hs-CRP and depression remains unclear. This study aimed to investigate the sex difference in the association between hs-CRP and depression. Data from the 2016 Korea National Health and Nutritional Examination Survey were used for our study. High hs-CRP was defined as >3.0 mg/L, while depression was determined using a cut-off score of 10 in the Patient Health Questionnaire-9. The study population comprised 5,483 Korean adults. Men with high hs-CRP levels showed statistically higher prevalence of depression than those with low hs-CRP levels (8.90% vs. 3.65%, P