Phase diagram and crossover phases of topologically ordered graphene zigzag nanoribbons: role of localization effects.

We computed the phase diagram of zigzag graphene nanoribbons as a function of on-site repulsion, doping, and disorder strength. The topologically ordered phase undergoes topological phase transitions into crossover phases, which are new disordered phases with non-universal topological entanglement entropy that exhibits significant variance. We explored the nature of non-local correlations in both the topologically ordered and crossover phases. In the presence of localization effects, strong on-site repulsion and/or doping weaken non-local correlations between the opposite zigzag edges of the topologically ordered phase. In one of the crossover phases, bothe-/2solitonic fractional charges and spin-charge separation were absent; however, charge-transfer correlations between the zigzag edges were possible. Another crossover phase contains solitonice-/2fractional charges but lacks charge transfer correlations. We also observed properties of non-topological, strongly disordered, and strongly repulsive phases. Each phase on the phase diagram exhibits a different zigzag-edge structure. Additionally, we investigated the tunneling of solitonic fractional charges under an applied voltage between the zigzag edges of undoped topologically ordered zigzag ribbons, and found that it may lead to a zero-bias tunneling anomaly.

Mediating effect of lower extremity muscle on the relationship between obesity and osteoarthritis in middle-aged and elderly women in Korea: based on the 2009-2011 Korea National Health and Nutrition Examination Survey.

OBJECTIVES: This study investigated whether the lower extremity muscle mass index (LMI) mediates the relationship between general obesity, central obesity, and knee osteoarthritis in middle-aged and elderly women in Korea. METHODS: Data of 2,843 women aged ≥50 years were collected from the Korean National Health and Nutrition Examination Survey conducted between 2009 and 2011. General obesity and central obesity were evaluated based on body mass index (BMI) and waist circumference (WC), calculated through anthropometric measurements and body composition assessments. LMI was calculated by dividing the muscle mass in both legs-measured using the dual-energy X-ray absorptiometry-by body weight. Knee osteoarthritis was defined as a Kellgren-Lawrence scale (KL) grade of ≥2 as assessed through radiographic images. RESULTS: Knee osteoarthritis prevalence, indicated by KL grades, was significantly higher in the general obesity and central obesity groups compared to the normal group, and conversely, lower with varying LMI levels. Using mediation analysis with bootstrapping and adjusting for covariates, we found that LMI mediated the relationship between BMI and KL (ß, 0.005; 95% confidence interval [CI], 0.000 to 0.010) and WC and KL grade (ß, 0.002; 95% CI, 0.001 to 0.003), explaining 4.8% and 6.7% of the total effects of BMI and WC on KL grade, respectively. CONCLUSIONS: The study suggested that LMI partially mediates the link between general obesity and/or central obesity and knee osteoarthritis, proposing that a higher proportion of lower limb muscle mass relative to body weight can alleviate the increased risk of knee osteoarthritis caused by obesity.

Pt Single Atoms Supported on Defect Ceria as an Active and Stable Dual-Site Catalyst for Alkaline Hydrogen Evolution.

This work evaluates the feasibility of alkaline hydrogen evolution reaction (HER) using Pt single-atoms (1.0 wt %) on defect-rich ceria (Pt1/CeOx) as an active and stable dual-site catalyst. The catalyst displayed a low overpotential and a small Tafel slope in an alkaline medium. Moreover, Pt1/CeOx presented a high mass activity and excellent durability, competing with those of the commercial Pt/C (20 wt %). In this picture, the defective CeOx is active for water adsorption and dissociation to create H* intermediates, providing the first site where the reaction occurs. The H* intermediate species then migrate to adsorb and react on the Pt2+ isolated atoms, the site where H2 is formed and released. DFT calculations were also performed to obtain mechanistic insight on the Pt1/CeOx catalyst for the HER. The results indicate a new possibility to improve the state-of-the-art alkaline HER catalysts via a combined effect of the O vacancies on the ceria support and Pt2+ single atoms.

Engineering core-shell hollow-sphere Fe3O4@FeP@nitrogen-doped-carbon as an advanced bi-functional electrocatalyst for highly-efficient water splitting.

Given the rapidly increasing energy demand and environmental pollution, to achieve energy conservation and emission reduction, hydrogen production has emerged as a promising alternative to traditional fossil fuels because of its high gravimetric energy density, and renewable and environmentally friendly characteristics. Herein, a core-shell hollow-sphere Fe3O4@FeP@nitrogen-doped-carbon (labeled as H-Fe3O4@FeP@NC) with a dual-interface, novel morphology, and superior conductivity is prepared as an advanced bi-functional electrocatalyst for electrochemical overall water splitting using a collaborative strategy comprising of facile self-assembly and phosphating. The prepared catalyst exhibits superior electrocatalytic activity compared to H-Fe3O4@NC and H-Fe3O4 for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Additionally, the overpotential of H-Fe3O4@FeP@NC for OER/HER (258/165 mV at 10 mA/cm2) is significantly lower than those of H-Fe3O4@NC (274/209 mV) and H-Fe3O4 (287/213 mV) at 10 mA/cm2. Meanwhile, the as-synthesized H-Fe3O4@FeP@NC, as an electrode pair, displays a low cell voltage of 1.69 V at 10 mA/cm2 and excellent stability after 100 h, indicating its practical application for overall water splitting. This work presents a practical and economical strategy toward the fabrication of catalyst for efficient water splitting and fuel cell.

Tailoring a N-Doped Nanoporous Carbon Host for a Stable Lithium Metal Anode.

Li metal is a promising anode candidate due to its high theoretical capacity and low electrochemical potential. However, dendrite formation and the resulting dead Li cause continuous Li consumption, which hinders its practical application. In this study, we realized N-doped nanoporous carbon for a stable Li metal host composed only of lightweight elements C and N through the simple calcination of a nitrogen-containing metal-organic framework (MOF). During the calcination process, we effectively controlled the amount of lithophilic N and the electrical conductivity of the N-doped porous carbons to optimize their performance as Li metal hosts. As a result, the N-doped porous carbon exhibited excellent electrochemical performances, including 95.8% coulombic efficiency and 91% capacity retention after 150 cycles in a full cell with an LFP cathode. The N-doped nanoporous carbon developed in this study can realize a stable Li metal host without adding lithium ion metals and metal oxides, etc., which is expected to provide an efficient approach for reliable Li metal anodes in secondary battery applications.

Interactive associations of smoking and physical activity with metabolic syndrome in adult men in Korea.

Introduction: This study aimed to investigate the association of smoking and physical activity (PA) with metabolic syndrome (MetS) in adult men in Korea. Methods: This study analyzed data of 7,229 adult men aged 19-64 years obtained from the 2014-2021 Korea National Health and Nutrition Examination Survey (KNHANES). Information on smoking habits was obtained using KNHANES data, while that on total PA (TPA), leisure-time PA (LTPA), and occupational PA (OPA) was collected using the Global Physical Activity Questionnaire. Smoking status was classified into non-smokers and smokers, and PA was categorized into three groups (total, leisure time, and occupational) according to the time spent engaging in moderate or high-intensity PA areas. The diagnosis of MetS was based on the Adult Treatment Program III of the National Cholesterol Education Program and Koreans' waist circumference criteria. Results: Logistic regression revealed that the risk of MetS was significantly lower in non-smokers than in smokers, even after adjusting for all covariates. The risk of MetS was significantly lower in individuals who engaged in at least 150 min of moderate- and high-intensity TPA or LTPA per week than in those who did not engage in PA. Furthermore, smokers who engaged in at least 150 min of moderate- to high-intensity TPA and LTPA per week had a significantly lower risk of MetS than those who did not engage in PA. Meanwhile, OPA was not associated with MetS. Conclusion: The findings suggest that engaging in moderate- to high-intensity TPA or LTPA for at least 150 min per week attenuates the risk of MetS caused by smoking.

Reduction of Structural Defects in the GaSb Buffer Layer on (001) GaP/Si for High Performance InGaSb/GaSb Quantum Well Light-Emitting Diodes.

Monolithic integration of GaSb-based optoelectronic devices on Si is a promising approach for achieving a low-cost, compact, and scalable infrared photonics platform. While tremendous efforts have been put into reducing dislocation densities by using various defect filter layers, exploring other types of extended crystal defects that can exist on GaSb/Si buffers has largely been neglected. Here, we show that GaSb growth on Si generates a high density of micro-twin (MT) defects as well as threading dislocations (TDs) to accommodate the extremely large misfit between GaSb and Si. We found that a 250 nm AlSb single insertion layer is more effective than AlSb/GaSb strained superlattices in reducing both types of defects, resulting in a 4× and 13× reduction in TD density and MT density, respectively, compared with a reference sample with no defect filter layer. InGaSb quantum well light-emitting diodes were grown on the GaSb/Si templates, and the effect of TD density and MT density on their performance was studied. This work shows the importance of using appropriate defect filter layers for high performance GaSb-based optoelectronic devices on standard on-axis (001) Si via direct epitaxial growth.

Mutual Information and Correlations across Topological Phase Transitions in Topologically Ordered Graphene Zigzag Nanoribbons.

Graphene zigzag nanoribbons, initially in a topologically ordered state, undergo a topological phase transition into crossover phases distinguished by quasi-topological order. We computed mutual information for both the topologically ordered phase and its crossover phases, revealing the following results: (i) In the topologically ordered phase, A-chirality carbon lines strongly entangle with B-chirality carbon lines on the opposite side of the zigzag ribbon. This entanglement persists but weakens in crossover phases. (ii) The upper zigzag edge entangles with non-edge lines of different chirality on the opposite side of the ribbon. (iii) Entanglement increases as more carbon lines are grouped together, regardless of the lines' chirality. No long-range entanglement was found in the symmetry-protected phase in the absence of disorder.

Cu(triNHC)-catalyzed polymerization of glycidol to produce ultralow-branched polyglycerol.

We have successfully synthesized a novel form of polyglycerol with an unprecedentedly low degree of branching (DB = 0.08-0.18), eliminating the need for glycidol protection. Leveraging the remarkable efficiency and selectivity of our Cu(triNHC) catalyst, comprising copper(i) ions and NHC ligands, we achieved a highly selective polymerization process. The proposed Cu-coordination mechanisms presented the formation of linear L1,3 units while effectively suppressing dendritic units. Consequently, our pioneering approach yielded polyglycerol with an ultralow DB and exceptional yields. To comprehensively assess the physical properties and topology of the synthesized polyglycerol, we employed 1H diffusion-ordered spectroscopy, size-exclusion chromatography, and matrix-assisted laser desorption/ionization-time of flight spectrometry. Remarkably, the ultralow-branched cyclic polyglycerol (DB = 0.08) synthesized at 0 °C showcased extraordinary characteristics, exhibiting the lowest diffusion coefficient and the highest molecular weight. This achievement establishes the significant potential of our polyglycerol with a low degree of branching, revolutionizing the field of biocompatible polymers.

Enhanced Thermal Pad Composites Using Densely Aligned MgO Nanowires.

Owing to the increasing demand for the miniaturization and integration of electronic devices, thermal interface materials (TIMs) are crucial components for removing heat and improving the lifetime and safety of electronic devices. Among these, thermal pads are reusable alternatives to thermal paste-type TIMs; however, conventional thermal pads comprise a homogeneous polymer with low thermal conductivity. Composite materials of thermally conducting fillers and polymer matrices are considered suitable alternatives to high-performance pad materials owing to their controllable thermal properties. However, they degrade the thermal performance of the filler materials at high loading ratios via aggregation. In this study, we propose novel nanocomposites using densely aligned MgO nanowire fillers and polydimethylsiloxane (PDMS) matrices. The developed nanocomposites ensured the enhanced thermal conducting properties, while maintaining mechanical flexibility. The three-step preparation process involves the (i) fabrication of the MgO structure using a freeze dryer; (ii) compression of the MgO structure; and (iii) the infiltration of PDMS in the structure. The resulting aligned composites exhibited a superior thermal conductivity (approximately 1.18 W m-1K-1) to that of pure PDMS and composites with the same filler ratios of randomly distributed MgO fillers. Additionally, the MgO/PDMS composites exhibited adequate electrical insulating properties, with a room-temperature resistivity of 7.92 × 1015 Ω∙cm.

Living Cationic Ring-Opening Polymerization of Hetero Diels-Alder Adducts to Give Multifactor-Controlled and Fast-Photodegradable Vinyl Polymers.

Precise control of multiple structural parameters associated with vinyl polymers is important for producing materials with the desired properties and functions. While the development of living polymerization methods has provided a way to control the various structural parameters of vinyl polymers, the concomitant control of their sequence and regioregularity remains a challenging task. To overcome this challenge, herein, we report the living cationic ring-opening polymerization of hetero Diels-Alder adducts. The scalable and modular synthesis of the cyclic monomers was achieved by a one-step protocol using readily available vinyl precursors. Subsequently, living polymerization of the cyclic monomers was examined, allowing the synthesis of vinyl polymers while controlling multiple factors, including molecular weight, dispersity, alternating sequence, head-to-head regioregularity, and end-group functionality. The living characteristics of the developed method were further demonstrated by block copolymerization. The synthesized vinyl polymers exhibited unique thermal properties and underwent fast photodegradation even under sunlight.

Quercetin mediated antimicrobial photodynamic treatment using blue light on Escherichia coli O157:H7 and Listeria monocytogenes.

Interest in using an antimicrobial photodynamic treatment (aPDT) for the microbial decontamination of food has been growing. In this study, quercetin, a substance found ubiquitously in plants, was used as a novel exogenous photosensitizer with 405 nm blue light (BL) for the aPDT on foodborne pathogens, and the inactivation mechanism was elucidated. The inactivation of Escherichia coli O157:H7 and Listeria monocytogenes in PBS solution by the quercetin and BL combination treatment reached a log reduction of 6.2 and more than 7.55 at 80 J/cm2 (68 min 21 s), respectively. When EDTA was added to investigate the reason for different resistance between two bacteria, the effect of aPDT was enhanced against E. coli O157:H7 but not L. monocytogenes. This result indicated that the lipopolysaccharide of Gram-negative bacteria operated as a protective barrier. It was experimentally demonstrated that quercetin generated the superoxide anion and hydrogen peroxide as the reactive oxygen species that oxidize and inactivate cell components. The damage to the bacterial cell membrane by aPDT was evaluated by propidium iodide, where the membrane integrity significantly (P < 0.05) decreased from 40 J/cm2 compared to control. In addition, DNA integrity of bacteria was significantly (P < 0.05) more decreased after aPDT than BL treatment. The inactivation results could be applied in liquid food industries for decontamination of foodborne pathogens, and the mechanisms data was potentially utilized for further studies about aPDT using quercetin.

Enhancing the Stability and Initial Coulombic Efficiency of Silicon Anodes through Coating with Glassy ZIF-4.

The high capacity of electrodes allows for a lower mass of electrodes, which is essential for increasing the energy density of the batteries. According to this, silicon is a promising anode candidate for Li-ion batteries due to its high theoretical capacity. However, its practical application is hampered by the significant volume expansion of silicon during battery operation, resulting in pulverization and contact loss. In this study, we developed a stable Li-ion anode that not only solves the problem of the short lifetime of silicon but also preserves the initial efficiency by using silicon nanoparticles covered with glassy ZIF-4 (SZ-4). SZ-4 suppresses silicon pulverization, contact loss, etc. because the glassy ZIF-4 wrapped around the silicon nanoparticles prevents additional SEI formation outside the silicon surface due to the electrically insulating characteristics of glassy ZIF-4. The SZ-4 realized by a simple heat treatment method showed 74% capacity retention after 100 cycles and a high initial efficiency of 78.7%.

Relative Handgrip Strength Mediates the Relationship between Hemoglobin and Health-Related Quality of Life in Older Korean Adults.

Background: Little is known regarding how anemia and handgrip strength influence the health-related quality of life (HRQoL) of older populations. This population-based study aimed to examine whether handgrip strength mediates the association between anemia and HRQoL in a representative sample of 6892 Korean adults aged ≥ 65 years (3753 females). Methods: HRQoL was assessed with the EuroQol-5 dimension. Anemia was defined according to World Health Organization (WHO) criteria, and handgrip strength was measured with a digital hand dynamometer. Results: Individuals with anemia were at increased risk for a lower HRQoL (odds ratio, OR = 1.285, p = 0.002) even after adjustment for age, sex, body mass index, income, marital status, education, physical activity, and multimorbidity compared with individuals without anemia (OR = 1). Individuals with weak handgrip strength were also at increased risk for a lower HRQoL (OR = 1.429, p < 0.001) even after adjustment for all the covariates compared with individuals with normal handgrip strength (OR = 1). Mediation analysis with a bootstrapping procedure showed that relative handgrip strength mediated the relationship between hemoglobin and HRQoL (95% confidence interval, CI 0.0192 to 0.0289) even after adjustment for all covariates, with 42.0% of the total effect of hemoglobin on HRQoL explained. Conclusions: The current findings suggest that the impact of anemia on HRQoL is partially mediated by weak handgrip strength, implying the clinical importance of having or maintaining adequate hemoglobin and handgrip strength via healthy lifestyle choices to maintain a high HRQoL later in life.

Surface activated zinc-glutarate for the copolymerization of CO2 and epoxides.

Zinc-glutarate (ZnGA) is a promising catalyst that can form polymers from CO2 and epoxides, thereby contributing to the development of CO2 utilization technologies and future sustainability. One of the obstacles to commercializing ZnGA in polymer industries is its low catalytic activity. In this study, we introduced activated two-dimensional (2D) ZnGA to improve its catalytic activity in polymerization. The morphology-controlled 2D ZnGA was treated with H3Co(CN)6, and a porous granular-type Co-modified ZnGA (Co-ZnGA) was prepared. The morphology of 2D ZnGA is a prerequisite for the activation by H3Co(CN)6. The catalytic properties of Co-ZnGA were evaluated by copolymerization of various epoxides and CO2, and exhibited catalytic activity of 855, 1540, 1190, and 148 g g-cat-1 with propylene oxide, 1,2-epoxyhexane, 1,2-epoxybutane, and styrene oxide, respectively. This study provided a new strategy using 2D ZnGA instead of conventional ZnGA for increasing the catalytic activity in CO2 polymerization.

Enhanced Luminance of CdSe/ZnS Quantum Dots Light-Emitting Diodes Using ZnO-Oleic Acid/ZnO Quantum Dots Double Electron Transport Layer.

The widely used ZnO quantum dots (QDs) as an electron transport layer (ETL) in quantum dot light-emitting diodes (QLEDs) have one drawback. That the balancing of electrons and holes has not been effectively exploited due to the low hole blocking potential difference between the valence band (VB) (6.38 eV) of ZnO ETL and (6.3 eV) of CdSe/ZnS QDs. In this study, ZnO QDs chemically reacted with capping ligands of oleic acid (OA) to decrease the work function of 3.15 eV for ZnO QDs to 2.72~3.08 eV for the ZnO-OA QDs due to the charge transfer from ZnO to OA ligands and improve the efficiency for hole blocking as the VB was increased up to 7.22~7.23 eV. Compared to the QLEDs with a single ZnO QDs ETL, the ZnO-OA/ZnO QDs double ETLs optimize the energy level alignment between ZnO QDs and CdSe/ZnS QDs but also make the surface roughness of ZnO QDs smoother. The optimized glass/ITO/PEDOT:PSS/PVK//CdSe/ZnS//ZnO-OA/ZnO/Ag QLEDs enhances the maximum luminance by 5~9% and current efficiency by 16~35% over the QLEDs with a single ZnO QDs ETL, which can be explained in terms of trap-charge limited current (TCLC) and the Fowler-Nordheim (F-N) tunneling conduction mechanism.

Light-to-Hydrogen Improvement Based on Three-Factored Au@CeO2/Gr Hierarchical Photocatalysts.

Recently, various attempts have been made for light-to-fuels conversion, often with limited performance. Herein we report active and lasting three-factored hierarchical photocatalysts consisting of plasmon Au, ceria semiconductor, and graphene conductor for hydrogen production. The Au@CeO2/Gr2.0 entity (graphene outer shell thickness of 2.0 nm) under visible-light irradiation exhibits a colossal achievement (8.0 µmol mgcat-1 h-1), which is 2.2- and 14.3-fold higher than those of binary Au@CeO2 and free-standing CeO2 species, outperforming the currently available catalysts. Yet, it delivers a high maximum quantum yield efficiency of 38.4% at an incident wavelength of 560 nm. These improvements are unambiguously attributed to three indispensable effects: (1) the plasmon resonant energy is light-excited and transferred to produce hot electrons localizing near the surface of Au@CeO2, where (2) the high-surface-area Gr conductive shell will capture them to direct hydrogen evolution reactions, and (3) the active graphene hybridized on the defect-rich surface of Au@CeO2 favorably adsorbs hydrogen atoms, which all bring up thorough insight into the working of a ternary Au@CeO2/Gr catalyst system in terms of light-to-hydrogen conversion.

Crystal Structures of the Plant Phospholipase A1 Proteins Reveal a Unique Dimerization Domain.

Phospholipase is an enzyme that hydrolyzes various phospholipid substrates at specific ester bonds and plays important roles such as membrane remodeling, as digestive enzymes, and the regulation of cellular mechanism. Phospholipase proteins are divided into following the four major groups according to the ester bonds they cleave off: phospholipase A1 (PLA1), phospholipase A2 (PLA2), phospholipase C (PLC), and phospholipase D (PLD). Among the four phospholipase groups, PLA1 has been less studied than the other phospholipases. Here, we report the first molecular structures of plant PLA1s: AtDSEL and CaPLA1 derived from Arabidopsis thaliana and Capsicum annuum, respectively. AtDSEL and CaPLA1 are novel PLA1s in that they form homodimers since PLAs are generally in the form of a monomer. The dimerization domain at the C-terminal of the AtDSEL and CaPLA1 makes hydrophobic interactions between each monomer, respectively. The C-terminal domain is also present in PLA1s of other plants, but not in PLAs of mammals and fungi. An activity assay of AtDSEL toward various lipid substrates demonstrates that AtDSEL is specialized for the cleavage of sn-1 acyl chains. This report reveals a new domain that exists only in plant PLA1s and suggests that the domain is essential for homodimerization.

Adding Estimated Cardiorespiratory Fitness to the Framingham Risk Score and Mortality Risk in a Korean Population-Based Cohort Study.

BACKGROUND: The added value of non-exercise-based estimation of cardiorespiratory fitness (eCRF) to cardiovascular disease (CVD) risk factors for mortality risk has not been examined in Korean populations. METHODS: This population-based prospective cohort study examined the relationship of the 10-year Framingham risk score (FRS) for CVD risk and eCRF with all-cause and CVD mortality in a representative sample of Korean adults aged 30 years and older. Data regarding a total of 38,350 participants (16,505 men/21,845 women) were obtained from the 2007-2015 Korea National Health and Nutrition Examination Survey (KNHANES). All-cause and CVD mortality were the main outcomes. The 10-year FRS point sum and eCRF level were the main exposures. RESULTS: All-cause and CVD mortality was positively correlated with the 10-year FRS point summation and inversely correlated with eCRF level in this study population. The protective of high eCRF against all-cause and CVD mortality was more prominent in the middle and high FRS category than in the low FRS category. Notably, the FRS plus eCRF model has better predictor power for estimating mortality risk compared to the FRS only model. CONCLUSIONS: The current findings indicate that eCRF can be used as an alternative to objectively measured CRF for mortality risk prediction.

Recent Advances in Diversity-Oriented Polymerization Using Cu-Catalyzed Multicomponent Reactions.

Diversification of polymer structures is important for imparting various properties and functions to polymers, so as to realize novel applications of these polymers. In this regard, diversity-oriented polymerization (DOP) is a powerful synthetic strategy for producing diverse and complex polymer structures. Multicomponent polymerization (MCP) is a key method for realizing DOP owing to its combinatorial features and high efficiency. Among the MCP methods, Cu-catalyzed MCP (Cu-MCP) has recently paved the way for DOP by overcoming the synthetic challenges of the previous MCP methods. Here the emergence and progress of Cu-MCP, its current challenges, and future perspectives are discussed.