Moderate hearing loss is related with social frailty in a community-dwelling older adults: The Korean Frailty and Aging Cohort Study (KFACS)

OBJECTIVES

To determine whether hearing loss is associated with social frailty in older adults.

METHODS

Cross-sectional analysis of cohort study data. Hearing was measured using of Pure-tone audiometry. Hearing loss was determined based on the average of hearing thresholds at 0.5, 1, and 2 kHz in the ear that had better hearing. Social frailty was defined based on the summation of the following 5 social components (1. Neighborhood meeting attendance 2. Talking to friend(s) sometimes 3.Someone gives you love and affection 4. Living alone 5. Meeting someone every day). Participants who had no correspondence to the components were considered non-social frailty; those with 1-2 components were considered social prefrailty; and those having 3 or more components were considered social frailty.

RESULTS

The prevalence of non-social frailty, social prefrailty, social frailty was 27.6%, 60.7% and 11.7% respectively. Of the five questions, two components (Neighborhood meeting attendance and Presence of someone who shows love and affection to the participants) were associated with hearing loss (p < 0.001). Compared to non-social frailty, the odds ratio of social frailty for hearing loss was 2.24 (95% CI 1.48-3.38) after adjusting for age, residential area, economic status, smoking, depressive disorder and MMSE, and 2.17 (95% CI 1.43-3.30) after further adjustments with physical frailty.

CONCLUSION

Hearing loss was associated with social frailty even after controlling confounding factors even including physical frailty.

Strong One-Dimensional Characteristics of Hole-Carriers in ReS2 and ReSe2

Each plane of layered ReS₂ and ReSe₂ materials has 1D chain structure, from which intriguing properties such as 1D character of the exciton states and linearly polarized photoluminescence originate. However, systematic studies on the 1D character of charge carriers have not been done yet. Here, we report on systematic and comparative studies on the energy-momentum dispersion relationships of layered transition metal dichalcogenides ReS₂ and ReSe₂ by angle resolved photoemission. We found that the valence band maximum or the minimum energy for holes is located at the high symmetric Z-point for both materials. However, the out-of-plane (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${k}_{z}$$\end{document}kz) dispersion for ReSe₂ (20 meV) is found to be much smaller than that of ReS₂ (150 meV). We observe that the effective mass of the hole carriers along the direction perpendicular to the chain is about 4 times larger than that along the chain direction for both ReS₂ and ReSe₂. Remarkably, the experimentally measured hole effective mass is about twice heavier than that from first principles calculation for ReS₂ although the in-plane anisotropy values from the experiment and calculations are comparable. These observation indicate that bulk ReS₂ and ReSe₂ are unique semiconducting transition metal dichalcogenides having strong one-dimensional characters.

Sleep Latency in Men and Sleep Duration in Women Can Be Frailty Markers in Community-Dwelling Older Adults: The Korean Frailty and Aging Cohort Study (KFACS)

OBJECTIVES

To test whether sleep disturbances are associated with frailty in older men and women.

DESIGN

Cross-sectional analysis of cohort study data. The participants were 1168 community-dwelling older adults aged 70 to 84 years who took part in the Korean Frailty and Aging Cohort Study and completed both self-reported sleep parameters and assessment of frailty. Univariate and multivariate survey logistic regression models were used to calculate odds ratios (OR) with 95% confidence intervals (CI) for frailty. Frailty was defined using the Fried's criteria.

RESULTS

Frailty was associated with sleep latency in men. The odds ratio for this association was 3.39 (95% CI 1.31-8.76) after adjusting for age, body mass index (BMI), physical activity, and select comorbidities, and 2.16 (95% CI 0.75-6.23) after further adjusting for depression. Frailty was associated with long sleep duration of more than 8 hours a night in women. The odds ratio for this association was 3.95 (95% CI, 1.27-12.33) after adjusting for age, BMI, physical activity, select comorbidities, and the number of medications.

CONCLUSION

Prolonged sleep latency (≥60 minutes) in men and long sleep duration (>8hr per night) in women were each independently associated with higher odds of frailty. Long sleep latency in elderly men and long sleep duration in elderly women may suggest they have a high chance of frailty.

Length of hospital stay after hip fracture surgery and 1-year mortality

There is ongoing effort to discharge patients early after hip fracture surgery to reduce the medical and economic burden. We tried to find whether there is any related side effect, and discovered that early discharge, especially before 10 days after surgery, is associated with higher mortality.

INTRODUCTION

The aim of this study was to analyze the association between the length of hospital stay after hip fracture and 1-year mortality in older adults aged ≥ 65 years old.

METHODS

We conducted a retrospective cohort study using the Korean National Health Insurance Service data to identify patients who were discharged after hip fracture surgery from 2007 to 2009 among 487,460 older adults of age ≥ 65 years. The lengths of stay involving hip fracture surgery were categorized at 10-day interval, and analyzed in relation to 1-year mortality from the date of hospital discharge.

RESULTS

A total of 4213 patients were discharged after hip fracture surgery, of whom 604 (14.3%) died within 1 year of discharge. The average length of stay was 30.7 days (standard deviation 24.5 days). The 1-year mortality was the highest for the length of stay ≤ 10 days group at 21.7%, followed by 15.2%, 14.3%, 13.3%, and 12.4% for > 40, 21-30, 31-40, and 11-20 days groups, respectively (p value 0.05). On Cox proportional hazard regression, the adjusted hazard ratio for length of stay ≤ 10 days group was 1.56 (95% confidence interval 1.14-2.12) against the reference group (11-20 days), while other groups did not show statistical significance. Higher risk of death was associated with increasing age, male gender, Charlson comorbidity index ≥3, subtrochanteric fracture, and discharge to tertiary care hospitals and long-term care hospitals.

CONCLUSION

Older adults discharged within 10 days of hospital admission for hip fracture surgery have higher 1-year mortality after discharge.

Large anomalous Hall current induced by topological nodal lines in a ferromagnetic van der Waals semimetal

Topological semimetals host electronic structures with several band-contact points or lines and are generally expected to exhibit strong topological responses. Up to now, most work has been limited to non-magnetic materials and the interplay between topology and magnetism in this class of quantum materials has been largely unexplored. Here we utilize theoretical calculations, magnetotransport and angle-resolved photoemission spectroscopy to propose Fe₃GeTe₂, a van der Waals material, as a candidate ferromagnetic (FM) nodal line semimetal. We find that the spin degree of freedom is fully quenched by the large FM polarization, but the line degeneracy is protected by crystalline symmetries that connect two orbitals in adjacent layers. This orbital-driven nodal line is tunable by spin orientation due to spin-orbit coupling and produces a large Berry curvature, which leads to a large anomalous Hall current, angle and factor. These results demonstrate that FM topological semimetals hold significant potential for spin- and orbital-dependent electronic functionalities.

Extremely Foldable and Highly Transparent Nanofiber-Based Electrodes for Liquid Crystal Smart Devices

The nylon 6 nanofiber-reinforced cellulose acetate (NF-r-CA) film as a fiber-based transparent substrate is used to develop the highly transparent electrodes with excellent durable and extremely foldable properties. Mechanical properties of the NF-r-CA films are greatly improved, suggesting that the nanofibers provide an effective reinforcement. The NF-r-CA transparent films show smooth surface morphologies (R_RMS ~ 27 nm) than as-spun nylon 6 nanofiber membrane, indicating the successful infiltration of cellulose acetate into the voids of nylon nanofiber membranes. The NF45-r-CA electrodes prepared using AgNWs concentration of 0.025 wt% and electrospinning time of 45 min are highly transparent (~90%), lower sheet resistance (~24 Ω sq^-1) and mechanically robust (59.7 MPa). The sheet resistance of NF45-r-CA electrodes remains almost constant, and the change ratio is less than 0.01% even after a repeated bending test of 10,000 cycles (bending radius ~1 mm), whereas ITO electrode shows gradual increase in sheet resistance and then eventually no electrical signal at about 270 cycles. We also demonstrate the successful fabrication of the foldable polymer-disperse liquid crystal film utilizing highly transparent NF45-r-CA electrode, which shows outstanding working stability after bending test of 500 cycles at an extreme bending radius of 1.5 mm.

Prediction of egg freshness during storage using electronic nose

The aim of the present study was to investigate the potential of a fast gas chromatography (GC) e-nose for freshness discrimination and for prediction of storage time as well as sensory and internal quality changes during storage of hen eggs. All samples were obtained from the same egg production farm and stored at 20 °C for 20 d. Egg sampling was conducted every 0, 3, 6, 9, 12, 16, and 20 d. During each sampling time, 4 egg cartons (each containing 10 eggs) were randomly selected: one carton for Haugh units, one carton for sensory evaluation and 2 cartons for the e-nose experiment. The e-nose study included 2 independent test sets; calibration (35 samples) and validation (28 samples). Every sampling time, 5 replicates were prepared from one egg carton for calibration samples and 4 replicates were prepared from the remaining egg carton for validation samples. Sensors (peaks) were selected prior to multivariate chemometric analysis; qualitative sensors for principal component analysis (PCA) and discriminant factor analysis (DFA) and quantitative sensors for partial least square (PLS) modeling. PCA and DFA confirmed the difference in volatile profiles of egg samples from 7 different storage times accounting for a total variance of 95.7% and 93.71%, respectively. Models for predicting storage time, Haugh units, odor score, and overall acceptability score from e-nose data were developed using calibration samples by PLS regression. The results showed that these quality indices were well predicted from the e- nose signals, with correlation coefficients of R² = 0.9441, R² = 0.9511, R² = 0.9725, and R² = 0.9530 and with training errors of 0.887, 1.24, 0.626, and 0.629, respectively. As a result of ANOVA, most of the PLS model results were not significantly (P > 0.05) different from the corresponding reference values. These results proved that the fast GC electronic nose has the potential to assess egg freshness and feasibility to predict multiple egg freshness indices during its circulation in the supply chain.

Predictive modeling for monitoring egg freshness during variable temperature storage conditions

The overall aim of this research was to develop egg freshness prediction models in terms of selected quality indices. Six experiments (4 constant temperatures and 2 variable temperatures) were carried out on hen eggs for a total period of 10, 21, 26, 13, and 105 d at storage temperatures of 30, 20, 20 to 10, 30 to 10, and 5 and 10°C, to observe trends in the relative weight loss (RWL), Haugh unit (HU), yolk index (YI), albumin index (AI), yolk pH, and albumin pH. The results showed that there was an increasing trend in the RWL and a decreasing trend in the YI, AI, and HU for all temperature conditions. The changes in the yolk and albumin pH were not uniform. The data from the constant temperature conditions were used to determine the coefficients of the egg quality prediction models, which consisted of the primary model controlling the change rate of the quality indicator at a temperature condition in differential equation form, and the secondary model controlling the change rate with temperature, which was in quadratic polynomial form. The models were applied to the data from the fluctuating temperature conditions, and the zeroth, third, and eighth order kinetic models described the stepwise change in the RWL, HU, and YI, respectively. The accuracy and bias factor values for the RWL, HU, and YI were 1.116 and 0.940, 1.028 and 1.001, and 1.038 and 0.966, respectively. It can be concluded that the models can be used to predict egg freshness in terms of the RWL, HU, and YI at any temperature condition with in the range of 5 to 30°C during storage.

The relationship between clinical characteristics including presence of exposed lesions and health-related quality of life (HRQoL) in patients with psoriasis: analysis from the nationwide epidemiologic study for psoriasis in Korea (EPI-PSODE study)

BACKGROUND

Psychological aspect and quality of life should be considered in treating patients with psoriasis.

OBJECTIVE

We sought to ascertain which clinical characteristics including presence of exposed lesions are associated with impairment of health-related quality of life (HRQoL) in patients with psoriasis.

METHODS

The EPI-PSODE study was a nationwide, multicenter, cross-sectional study conducted in Korea that included 1260 adult patients with psoriasis. In addition to clinical characteristics including presence of exposed lesions, data were collected using the Psoriatic Arthritis (PsA) Screening and Evaluation (PASE), Dermatology Life Quality Index (DLQI), MOS 36-Item Short-Form Health Survey (SF-36), Work Productivity and Activity Impairment Questionnaire Psoriasis (WPAI: PSO) and Medication Satisfaction Questionnaire (MSQ).

RESULTS

Patients with a DLQI score > 5 (n = 990) were younger, had an earlier onset of psoriasis, scored higher on the Psoriasis Area and Severity Index (PASI), had higher body surface area (BSA) and had higher PASE scores than patients with DLQI ≤ 5 (n = 266). The group of patients with exposed lesions (n = 871) were younger and male predominance, earlier onset of psoriasis, longer disease duration, higher PASI/BSA score and a higher proportion with drinking and smoking history each than the group of patients without exposed lesions (n = 389). Presence of exposed lesions negatively influenced DLQI, 36-Item Short-Form Health Survey (SF-36) (mental component), presenteeism, total work productivity impairment and total activity impairment in the WPAI: PSO. In multiple regression model, PASI score was the only variable which was significantly associated with all HRQoL measures. Presence of exposed lesions was a significant factor affecting DLQI and SF-36 (mental).

CONCLUSION

The presence of exposed lesions has a negative impact on quality of life, mental health and work productivity. Therefore, effective treatments are particularly needed for psoriasis patients with exposed lesions.

Transformative piezoelectric enhancement of P(VDF-TrFE) synergistically driven by nanoscale dimensional reduction and thermal treatment

Despite the significant potential of organic piezoelectric materials in the electro-mechanical or mechano-electrical applications that require light and flexible material properties, the intrinsically low piezoelectric performance as compared to traditional inorganic materials has limited their full utilization. In this study, we demonstrate that dimensional reduction of poly(vinylidene fluoride trifluoroethylene) (P(VDF-TrFE)) at the nanoscale by electrospinning, combined with an appropriate thermal treatment, induces a transformative enhancement in piezoelectric performance. Specifically, the piezoelectric coefficient (d₃₃) reached up to -108 pm V^-1, approaching that of inorganic counterparts. Electrospun mats composed of thermo-treated 30 nm nanofibers with a thickness of 15 μm produced a consistent peak-to-peak voltage of 38.5 V and a power output of 74.1 μW at a strain of 0.26% while sustaining energy production over 10k repeated actuations. The exceptional piezoelectric performance was realized by the enhancement of piezoelectric dipole alignment and the materialization of flexoelectricity, both from the synergistic effects of dimensional reduction and thermal treatment. Our findings suggest that dimensionally controlled and thermally treated electrospun P(VDF-TrFE) nanofibers provide an opportunity to exploit their flexibility and durability for mechanically challenging applications while matching the piezoelectric performance of brittle, inorganic piezoelectric materials.

EuroQol Visual Analogue Scale (EQ-VAS) as a Predicting Tool for Frailty in Older Korean Adults: The Korean Frailty an Aging Cohort Study (KFACS)

OBJECTIVES

This study was conducted to determine the cutoff value and efficacy of the EuroQol Visual Analogue Scale (EQ-VAS) for predicting frailty.

DESIGN

The EQ-VAS medians (Interquartile Range) were compared and analyzed against the FFI.

PARTICIPANTS

The subjects were 1471 older adults aged 70 to 84 years who had completed both EQ-VAS and Fried Frailty index (FFI) in the first baseline year (2016) of the Korean Frailty and Aging Cohort Study.

RESULTS

Of the 1471 subjects,600 were classified as robust, 716 as pre-frail, and 155 as frail. The median EQ-VAS scores were 80.00 (20.00) for robust, 75.00 (25.00) for pre-frail, and 60.00 (25.00) for frail subjects.The medians of all five components of the FFI, weight loss (70.00 vs. 80.00), grip strength (70.00 vs. 80.00), exhaustion (70.00 vs. 80.00), walking velocity (70.00 vs. 80.00), and physical activity (70.00 vs. 80.00), were lower in the abnormal groups. We tested the efficacy of EQ-VAS as a diagnostic tool to predict frailty, and the area under the curve of EQ-VAS was 0.71 withthe optimal cut-off value of 72.

CONCLUSION

EQ-VAS presented negative correlation with FFI, and the optimal cut off value for frailty was 72. These results suggest that EQ-VAS is a valuable tool for assessing frailty andmay be a good predictor of frailty in Korean elderly population.

NiCo2S4 nanosheet-decorated 3D, porous Ni film@Ni wire electrode materials for all solid-state asymmetric supercapacitor applications

Wire type supercapacitors with high energy and power densities have generated considerable interest in wearable applications. Herein, we report a novel NiCo₂S₄-decorated 3D, porous Ni film@Ni wire electrode for high performance supercapacitor application. In this work, a facile method is introduced to fabricate a 3D, porous Ni film deposited on a Ni wire as a flexible electrode, followed by decoration with NiCo₂S₄ as an electroactive material. The fabricated NiCo₂S₄-decorated 3D, porous Ni film@Ni wire electrode displays a superior performance with an areal and volumetric capacitance of 1.228 F cm^-2 and 199.74 F cm^-3, respectively, at a current density of 0.2 mA cm^-1 with a maximum volumetric energy and power density (E_V: 6.935 mW h cm^-3; P_V: 1.019 W cm^-3). Finally, the solid state asymmetric wire type supercapacitor is fabricated using the fabricated NiCo₂S₄-decorated 3D, porous Ni film@Ni wire as a positive electrode and N-doped reduced graphene oxide (N-rGO) as a negative electrode and this exhibits good areal and volumetric capacitances of C_A: 0.12 F cm^-2 and C_V: 19.57 F cm^-2 with a higher rate capability (92%). This asymmetric wire type supercapacitor demonstrates a low leakage current and self-discharge with a maximum volumetric energy (E_V: 5.33 mW h cm^-3) and power (P_V: 855.69 mW cm^-3) density.

Generation of interspecies limited chimeric nephrons using a conditional nephron progenitor cell replacement system

Animal fetuses and embryos may have applications in the generation of human organs. Progenitor cells may be an appropriate cell source for regenerative organs because of their safety and availability. However, regenerative organs derived from exogenous lineage progenitors in developing animal fetuses have not yet been obtained. Here, we established a combination system through which donor cells could be precisely injected into the nephrogenic zone and native nephron progenitor cells (NPCs) could be eliminated in a time- and tissue-specific manner. We successfully achieved removal of Six2+ NPCs within the nephrogenic niche and complete replacement of transplanted NPCs with donor cells. These NPCs developed into mature glomeruli and renal tubules, and blood flow was observed following transplantation in vivo. Furthermore, this artificial nephron could be obtained using NPCs from different species. Thus, this technique enables in vivo differentiation from progenitor cells into nephrons, providing insights into nephrogenesis and organ regeneration.

The transplantation of tissue-specific progenitor cells may be an approach in organ regeneration. Here the authors show that the nephron progenitor population of a developing mouse kidney, when ablated, can be replaced by exogenously supplied rat nephron progenitors, generating interspecies nephrons.

VUV spectroscopy in impurity injection experiments at KSTAR using prototype ITER VUV spectrometer

The ITER vacuum ultra-violet (VUV) core survey spectrometer has been designed as a 5-channel spectral system so that the high spectral resolving power of 200-500 could be achieved in the wavelength range of 2.4-160 nm. To verify the design of the ITER VUV core survey spectrometer, a two-channel prototype spectrometer was developed. As a subsequent step of the prototype test, the prototype VUV spectrometer has been operated at KSTAR since the 2012 experimental campaign. From impurity injection experiments in the years 2015 and 2016, strong emission lines, such as Kr xxv 15.8 nm, Kr xxvi 17.9 nm, Ne vii 46.5 nm, Ne vi 40.2 nm, and an array of largely unresolved tungsten lines (14-32 nm) could be measured successfully, showing the typical photon number of 10¹³-10¹⁵ photons/cm² s.

Highly Porous Polymer Matrices as a Three-Dimensional Culture System for Hepatocytes

Hepatocyte-based therapies (e.g., hepatocyte transplantation and extracorporeal support devices) may provide alternative therapies to treat patients with liver disease, but suitable approaches to localize these cells to a given location while maintaining liver-specific gene expression must be developed. The suitability of highly porous three-dimensional sponges fabricated from poly (l-lactic acid) [PLLA] as an hepatocyte culture system was evaluated in this study. Sponges were fabricated utilizing a particulate leaching technique, and were approximately 95% porous, with an average pore diameter of 180 μm. Hepatocytes seeded into these sponges adhered and remained viable for 14 days. However, the secretion rate of albumin from these cells, an indication of liver-specific gene expression, was low (approximately 6 pg/cell/day at day 1), and decreased steadily over the 14 days of the experiment. Coating sponges with collagen, and more preferably, immobilizing cells within the PLLA sponges with a collagen gel, led to enhanced cell survival and albumin secretion at all time points. These data suggest that porous PLLA sponges may provide a novel system for long-term culture of hepatocytes, and proper design of the system may allow the liver-specific gene expression of hepatocytes transplanted in these matrices to be enhanced.

Reduction of Slit Diaphragm-associated Molecules by Sirolimus: Is it Enough to Induce Proteinuria?

Sirolimus (SRL), a mammalian target of rapamycin inhibitor, is widely used in transplantation, but the mechanisms whereby it induces adverse effects, such as proteinuria and edema, remain unclear. To determine whether isolated SRL induces proteinuria or not, the authors intraperitoneally injected C57BL/6 mice with different doses of SRL (0 mg/[kg·d], 3 mg/[kg·d], 10 mg/[kg·d], or 30 mg/[kg·d]) for 24 days. Urinary albumin excretion was then quantified using a double-sandwich enzyme-linked immunosorbent assay, and serum creatinine levels were measured using a single dry-film chemistry auto-analyzer. The mRNA expression levels of various genes were also measured by polymerase chain reaction. Urinary albumin was not detected in the SRL-treated mice, but serum creatinine levels were found to increase dose-dependently and were significantly higher in the animals treated with 30 mg/kg of SRL than in untreated controls. Glomerular mRNA expression profiling showed down-regulations of podocyte-related genes (Wilms tumor 1, synaptopodin, nephrin, CD2-associated protein, and podocin) and of transforming growth factor-beta (a marker of fibrosis) in sirolimus-treated mice. In addition, expressions of the antiapoptotic genes Bcl-2 and Bcl-xL were also down-regulated. Furthermore, the protein levels of these genes in mice kidney were also decreased by sirolimus. Although sirolimus treatment reduced the expressions of slit diaphragm-associated molecules and increased serum creatinine levels, it failed to induce proteinuria. Our findings indicate that proteinuria is not induced by isolated SRL treatment. Further studies are required to identify conditions in which sirolimus induces proteinuria.