Search

Mutations in the Microrchidia CW-type zinc finger 2 (MORC2) GHKL ATPase module cause a broad range of neuropathies, such as Charcot-Marie-Tooth disease type 2Z; however, the aetiology and therapeutic strategy are not fully understood. Previously, we reported that the Morc2a p.S87L mouse model exhibited neuropathy and muscular dysfunction through DNA damage accumulation. In the present study, we analysed the gene expression of Morc2a p.S87L mice and designated the primary causing factor. We investigated the pathological pathway using Morc2a p.S87L mouse embryonic fibroblasts and human fibroblasts harbouring MORC2 p.R252W. We subsequently assessed the therapeutic effect of gene therapy administered to Morc2a p.S87L mice. This study revealed that Morc2a p.S87L causes a protein synthesis defect, resulting in the loss of function of Morc2a and high cellular apoptosis induced by high hydroxyl radical levels. We considered the Morc2a GHKL ATPase domain as a therapeutic target because it simultaneously complements hydroxyl radical scavenging and ATPase activity. We used the adeno-associated virus (AAV)-PHP.eB serotype, which has a high CNS transduction efficiency, to express Morc2a or Morc2a GHKL ATPase domain protein in vivo. Notably, AAV gene therapy ameliorated neuropathy and muscular dysfunction with a single treatment. Loss-of-function characteristics due to protein synthesis defects in Morc2a p.S87L were also noted in human MORC2 p.S87L or p.R252W variants, indicating the correlation between mouse and human pathogenesis. In summary, CMT2Z is known as an incurable genetic disorder, but the present study demonstrated its mechanisms and treatments based on established animal models. This study demonstrates that the Morc2a p.S87L variant causes hydroxyl radical-mediated neuropathy, which can be rescued through AAV-based gene therapy. [ABSTRACT FROM AUTHOR]

Herein, a Timoshenko–Ehrenfest beam‐based reconfigurable elastic metasurface is introduced that can perform multifunctional wave phenomena within a single substrate, featuring high transmission in the ultrabroadband frequency range. Conventional elastic metasurfaces are typically limited to specific purposes and frequencies, thereby imposing significant constraints on their practical application. The approach involves assembly‐components with various geometries on a substrate for reconfigurability, enabling to easily control and implement multifunctional wave phenomena, including anomalous‐refraction, focusing, self‐acceleration, and total‐reflection. This is the first study on elastic metasurfaces to theoretically analyze the dispersion relation based on the Timoshenko–Ehrenfest beam theory, which considers shear deformations and rotational inertia. The analytical model is validated by demonstrating an excellent agreement with numerical and experimental results. The findings include full‐wave harmonic simulations and experimentally visualized fields for measuring various wave modulations. Furthermore, the practicality of the system is verified by significantly enhancing the piezoelectric energy harvesting performance within the focusing configuration. It is believed that the reconfigurable elastic metasurface and analytical model based on the Timoshenko–Ehrenfest beam theory have vast applications such as structural health monitoring, wireless sensing, and Internet of Things. [ABSTRACT FROM AUTHOR]

Copper oxide (Cu2O) is a promising p‐type material owing to its high absorption coefficient, suitable bandgap width, chemical stability, nontoxicity, and abundance. In this study, the effect of postdeposition annealing (PDA) on the electrical properties of Cu2O thin films deposited on silicon carbide (SiC) substrates is investigated. The films are subjected to PDA using radio‐frequency sputtering at various temperatures in air. During PDA, the Cu2O films are maintained at <300 °C and transitioned to cupric oxide (CuO) at 400 °C. The as‐deposited Cu2O film exhibits a low oxidation peak (Cu2+), whereas the phase‐transformed CuO films exhibit a higher binding energy with the emergence of satellite peaks. The rectification ratios of the Cu2O device annealed at 300 °C and CuO device annealed at 400 °C are determined as 2.02 × 107 and 1.01 × 105, respectively, denoting the substantial enhancement of approximately 55.04 for the Cu2O/SiC device and degradation of approximately 0.28 for the CuO/SiC device relative to their non‐annealed counterparts. Therefore, in this study, the significant improvement in the performance of Cu2O thin films with the meticulous deposition control of potential p‐type materials, such as Cu2O and CuO, for high‐throughput and low‐cost electronic applications is demonstrated. [ABSTRACT FROM AUTHOR]

This paper addresses a joint training approach applied to a pipeline comprising speech enhancement (SE) and automatic speech recognition (ASR) models, where an acoustic tokenizer is included in the pipeline to leverage the linguistic information from the ASR model to the SE model. The acoustic tokenizer takes the outputs of the ASR encoder and provides a pseudo-label through K-means clustering. To transfer the linguistic information, represented by pseudo-labels, from the acoustic tokenizer to the SE model, a cluster-based pairwise contrastive (CBPC) loss function is proposed, which is a self-supervised contrastive loss function, and combined with an information noise contrastive estimation (infoNCE) loss function. This combined loss function prevents the SE model from overfitting to outlier samples and represents the pronunciation variability in samples with the same pseudo-label. The effectiveness of the proposed CBPC loss function is evaluated on a noisy LibriSpeech dataset by measuring both the speech quality scores and the word error rate (WER). The experimental results reveal that the proposed joint training approach using the described CBPC loss function achieves a lower WER than the conventional joint training approaches. In addition, it is demonstrated that the speech quality scores of the SE model trained using the proposed training approach are higher than those of the standalone-SE model and SE models trained using conventional joint training approaches. An ablation study is also conducted to investigate the effects of different combinations of loss functions on the speech quality scores and WER. Here, it is revealed that the proposed CBPC loss function combined with infoNCE contributes to a reduced WER and an increase in most of the speech quality scores. [ABSTRACT FROM AUTHOR]

Manipulating elastic waves of all polarizations is highly challenging due to the complex behavior of elastic waves. To achieve simultaneous broadband vibration attenuation and energy harvesting across all polarizations of elastic waves at low‐frequency ranges, a chiral mechanical metamaterial‐based energy harvester is proposed in this study. The systematic development of a complete bandgap and defect structure is achieved through theoretical eigenfrequency analysis and numerical simulations. The defect structure is incorporated to induce defect modes for all wave polarizations within the complete bandgap region, ensuring their compatibility with the overall shape of the structure. The proposed chiral mechanical metamaterial with defect (CMMD) demonstrated significant performance improvements, achieving electrical output power enhancements that are 20.5 times for flexural waves and 511.4 times for longitudinal‐torsional waves compared to the defectless chiral mechanical metamaterial. This study accentuates the thoughtful design and multifaceted utility of chiral mechanical metamaterials, paving the way for their application not only in energy harvesting but also in wave attenuation for various polarizations. [ABSTRACT FROM AUTHOR]

Tramadol, a weak μ-opioid receptor agonist, has been used worldwide for pain management. It is considered to have a favorable safety profile without serious adverse events; however, safety issues of respiratory depression were proposed by regulatory governments. We aimed to examine the risk and contributing factors associated with tramadol-related respiratory depression using a real-world database, VigiBase. Disproportionality analysis of tramadol and tramadol/paracetamol was performed using proportional reporting ratios, reporting odds ratios, and information components for all drugs and opioids. Factors related to respiratory depression, including sex, age, presence of abuse, death, and various concomitant medications, were evaluated. Among 140,721 tramadol reports, respiratory depression was reported in 1126 cases, 81.3% of which were deemed serious. Five adverse events were detected as signals of tramadol-related acute central respiratory depression (ACRD) in 882 reports. A higher proportion of ACRD cases in children and adolescents was observed than all adverse events cases of tramadol. Concomitant users of CYP2D6 inhibitors, opioids, benzodiazepines, and anti-depressant drugs showed a higher proportion in ACRD cases than non-ACRD cases. ACRD was related to drug abuse and death. This pharmacovigilance study, using VigiBase, confirmed a high risk of respiratory depression (a serious, potentially fatal adverse event) secondary to the use of tramadol, especially in pediatric patients, drug abusers, or during concomitant use of opioids, benzodiazepines, or antidepressants. [ABSTRACT FROM AUTHOR]

The effects of a reduction in area (RA) and the speed ratio between the top and bottom rolls on a shear strain and the crystallographic texture evolution of Al-Si-Mg (1.0%Si-0.6%Mg) aluminum alloys fabricated by twin roll casting (TRC) were comprehensively examined experimentally and through numerical predictions. Initial twin-roll casted strips had a texture gradient from the surface to the center. 〈 111 〉 //ND textures were found in the surface layer, and weak rolling textures existed in the center of the strip. The distributions of shear and plane strain compression (PSC) textures varied with the RA and differential speed ratio. Strong shear textures including a rotated cube, { 100 } 〈 011 〉 , were obtained from both the symmetric and differential speed rolling processes. Symmetric rolling with a different reduction in area (SRDRA) produced shear textures mainly in the surface layer. Differential speed rolling (DSR) caused dynamic shear textures along the thickness direction, not limited to the surface. Based on the finite element method and crystal plasticity, the effects of different RA values, differential speed ratios, and friction coefficients on shear strain and texture evolution are discussed in detail. Loads measured from work rolls during DSR decreased with an increase in the speed ratio. [ABSTRACT FROM AUTHOR]

In this study, we analytically, numerically, and experimentally investigated a high-performance confocal piezoelectric energy harvesting system. We achieved a significantly enhanced electrical performance through a Mikaelian lens, which achromatically focuses ambient elastic waves, resulting in the formation of a highly amplified strain energy field in the piezoelectric energy harvester. Previous studies on piezoelectric energy harvesting platforms have limitations, such as the focal position changing with operating frequencies and impedance mismatching owing to inclusions or holes. To address these problems, we utilized the self-focusing ability based on the conformal mapping theory and achromatic ability based on the Kirchhoff–Love thin plate theory to design our Mikaelian lens-based piezoelectric energy harvesting platform. The proposed platform demonstrates a remarkable elastic wave focusing ability at an identical focal position for a broad frequency range. The experimentally visualized wave fields matched well with the numerically calculated full-wave harmonic simulation results. We achieved highly amplified output power up to 1.44 mW within a broad range from 40 to 60 kHz out of the same focal point owing to confined elastic wave energy; the output power extracted at this confocal position was up to 3.76 times higher than that extracted at the lens start position. Our highly performance and broadband achromatic piezoelectric energy harvesting platform lays an attractive foundation for designing potential applications, such as wireless sensing, structural health monitoring, and biomedical devices. [ABSTRACT FROM AUTHOR]

Simple Summary: The price of feed ingredients has been drastically increasing over the last decade, and thus the methods for improving nutrient digestibility and utilization with various feed ingredients have been widely studied in the field of the swine industry. One of the most efficacious approaches to enhancing nutrient digestibility and utilization is the manipulation of feed particle size. Nonetheless, limited research has been conducted on the impact of varying particle sizes of feeds with high fiber content. Dietary fiber is composed of several components, including β-glucan, arabinoxylan, and cellulose, which exhibit distinct physiological effects on the small and large intestines. The compositions and proportions of these components can influence and modulate nutrient digestibility in the small and large intestines of pigs. The objective of the present investigation was to examine the potential for enhanced nutrient and fiber digestibility in growing pigs through the reduction of particle size in barley and wheat diets. Similar ileal and total nutrient digestibility were observed in pigs fed diets containing fine and coarse wheat; however, pigs consuming coarse barley exhibited reduced nutrient digestibility compared to the other diets. Consequently, the present study shows that nutrient digestibility was more influenced by reduced particle size in barley than wheat, most likely because of the rigid fiber structure of barley and barley hull. The objective of this investigation was to study the effects of different cereal types, barley and wheat, with different particle sizes (PS) on the recovery of ileal digesta and fecal excretion, digestion of nutrients and fiber components, mean transit time (MTT), and short-chain fatty acid content and composition in growing pigs studied in two experiments. Five barrows with ileal cannulas (initial BW 35.9 ± 1.5 kg) in Experiment 1 and thirty-two castrated pigs (30.8 ± 1.3 kg) in Experiment 2 were fed four different diets: barley fine, barley coarse, wheat fine and wheat coarse diets. The cereal type and PS did not influence the relative weight of the small and large intestines and pH of digesta, whereas MTT in the large intestine of pigs fed the coarse barley diet was lower compared to pigs fed other diets (p < 0.05). Pigs fed the coarse barley diet had lower apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients and fiber (p < 0.05), whereas pigs fed the fine barley diet had similar AID and ATTD to pigs fed wheat fine and coarse diets (p < 0.05). In conclusion, the barley diet was more influenced by PS in comparison to wheat, thereby inducing lower AID and ATTD of nutrient. [ABSTRACT FROM AUTHOR]

Simple Summary: Nutrient waste management poses significant challenges associated with environmental concerns and feed expenses for the pig industry. Additionally, including high levels of crude protein in pig diets has been linked to postweaning diarrhea and protein fermentation in the large intestine compared to diets with a lower protein content, which can impair gut health. This study was conducted to assess the impact of low-protein diets on weaning to finishing pigs related to growth performance, nutrient digestibility, and meat quality. Our findings indicate that when supplemented with appropriate amino acids, low-protein diets do not negatively affect growth performance or nutrient digestibility in weaning to finishing pigs. Furthermore, the quality was superior in pigs fed low-protein diets as opposed to those fed high-protein diets. Consequently, employing low-crude-protein diets in weaning to finishing pigs is recommended. This study aimed to evaluate optimal crude protein (CP) levels based on the National Research Council guidelines from 1998 and 2012 and their impacts on growth performance, fecal score, blood profiles, nutrient digestibility, and carcass characteristics of weaning to finishing pigs. Four diets were established in this experiment: high-protein (HP), medium-high-protein (MHP), medium-low-protein (MLP), and low-protein (LP). The HP diet followed the NRC (1998) guidelines, while the MHP diet reduced the CP content by 1%. The MLP diet had 1.5% lower CP content than the HP diet. The LP diet followed the NRC guideline of 2012, which suggests less protein than the NRC guideline of 1998. There were no significant differences in body weight, average daily feed intake, or nutrient digestibility. However, the average daily gain (ADG) of pigs fed the LP diet at 7–10 weeks was lower than in the other treatments, whereas the ADG of the pigs fed the LP diet was higher compared with that of pigs fed the other diets, showing compensatory growth in finishing periods (p < 0.05). The blood urea nitrogen of pigs fed the LP diet showed the lowest value, whereas the highest value was found in pigs fed the HP diet, and the other two diets were similar to the HP diet or positioned between the HP and LP diets (p < 0.05). Water holding capacity, cooking loss, shear force, and pH in the longissimus muscle were not influenced by varying dietary CP levels (p > 0.05), but the hunter values L and b were increased in pigs fed the LP diet (p < 0.05). Conclusively, a low-protein diet did not negatively affect growth performance, nutrient digestibility, or meat quality. [ABSTRACT FROM AUTHOR]

Herein, we report the in‐situ synthesis of amorphous GeSe/CNT composite via defective‐carbon‐mediated chemical bonding for ultrastable Na‐ion storage. Structural defects in CNTs play a crucial role in the chemical bonding and bonding strength in GeSe/CNTs composites. Specifically, the bonding strength tends to increase with increasing defect concentrations of CNTs. Remarkably, the strong chemical bonding between GeSe and CNTs significantly weakens Ge−Se bonds and promotes amorphization of GeSe, thus facilitating a reversible conversion reaction and enhancing Na‐ion diffusion. Consequently, GeSe/CNTs composite exhibits outstanding cyclability of 87.9% even after 1000 cycles at 1 A g−1 and a high‐rate capability of 288.3 mA h g−1 at 10 A g−1. Our work presents a promising approach for the amorphization of electrode materials enabled by the defective‐carbon‐mediated strong chemical bonding for Li‐, Na‐, and K‐ion batteries. [ABSTRACT FROM AUTHOR]

In this paper, we propose an end-to-end (E2E) neural network model to detect autism spectrum disorder (ASD) from children's voices without explicitly extracting the deterministic features. In order to obtain the decisions for discriminating between the voices of children with ASD and those with typical development (TD), we combined two different feature-extraction models and a bidirectional long short-term memory (BLSTM)-based classifier to obtain the ASD/TD classification in the form of probability. We realized one of the feature extractors as the bottleneck feature from an autoencoder using the extended version of the Geneva minimalistic acoustic parameter set (eGeMAPS) input. The other feature extractor is the context vector from a pretrained wav2vec2.0-based model directly applied to the waveform input. In addition, we optimized the E2E models in two different ways: (1) fine-tuning and (2) joint optimization. To evaluate the performance of the proposed E2E models, we prepared two datasets from video recordings of ASD diagnoses collected between 2016 and 2018 at Seoul National University Bundang Hospital (SNUBH), and between 2019 and 2021 at a Living Lab. According to the experimental results, the proposed wav2vec2.0-based E2E model with joint optimization achieved significant improvements in the accuracy and unweighted average recall, from 64.74% to 71.66% and from 65.04% to 70.81%, respectively, compared with a conventional model using autoencoder-based BLSTM and the deterministic features of the eGeMAPS. [ABSTRACT FROM AUTHOR]

In this work, we study the mitigation of stress waves in composite-based woodpile phononic crystals composed of heterogeneous cylindrical rods, whose bending mode exhibits local resonant behavior that strongly interferes with external perturbation. Impulse excitation in this system is transformed into several modulated wave patterns depending on resonant frequencies and their mechanical properties. Thus, these mechanisms have been a candidate for novel methods of shock mitigation without relying on material dissipation. Here, we suggest the mechanical system consisting of the unit cell's composite configuration as an approach for more efficient shock attenuation. To efficiently analyze the nonlinear wave dynamics of the proposed systems, we present an extended discrete element model (DEM) resulting from a combination of an analytic beam theory with the discretization model. We numerically and experimentally demonstrate extreme dispersive waves for shock mitigation by adjusting the weighted composition ratio of the heterogeneous cylinder. Using the verified DEM, we also investigate the strong attenuation performance of incident impulse in disorder-induced systems with different nonlinear strengths. We, thus, expect that these composite-based mechanical systems could be used to design tunable modulation energy transport and efficient impact protector devices. [ABSTRACT FROM AUTHOR]

Development of Li metal batteries is hindered by preferential accumulations of Li metal on the upper surface of the 3D host electrode, which blocks ion-transport pathways and causes a loss of host utilization. Decreasing the tortuosity of the host is an effective way to accelerate ion transport, however, no previous studies have modified host particles to decrease their tortuosity. Herein, we report the low-tortuosity modulation of a microspherical graphene assembly host to stabilize Li metal anodes by introducing in-plane nano-perforations into graphene. In the low-tortuosity graphene assembly host, graphene sheets are perforated with ∼5 nm in-plane nano-perforations evenly spaced and separated by ∼15 nm. These nano-perforations with lithiophilic edges provide low-tortuosity channels between different layers of graphene that behave as shortcuts for ion diffusion, thereby facilitating ion transport and uniform plating throughout the graphene assembly. The low-tortuosity graphene host maintains a high Coulombic efficiency of 97.9% for 400 cycles, with a low overpotential of 21 mV and stable Li plating/stripping performance at a high current density of 5 mA cm−2. Furthermore, it achieves a high volumetric capacity of 1000 mA h cm−3 for the host electrode. This study provides new insights into low-tortuosity, high-lithiophilicity hosts for 3D Li metal anodes. [Display omitted] [ABSTRACT FROM AUTHOR]

This study investigated the effects of nano-silica (NS) and silica fume (SF) on the hydration reaction of high-volume fly ash cement (HVFC) composites. In order to solve the dispersibility problem caused by the agglomeration of NS powder, NS and NSF solutions were prepared. NS content and SF content were used as main variables, and an HVFC paste was prepared in which 50% of the cement volume was replaced by fly ash (FA). The initial heat of hydration was measured using isothermal calorimetry to analyze the effects of NS and SF on the initial hydration properties of the HVFC. In addition, the compressive strength was analyzed by age. The refinement of the pore structure by the nanomaterial was analyzed using mercury intrusion porosimetry (MIP). The results show that the addition of NS and SF shortened the setting time and induction period by accelerating the initial hydration reaction of HVFC composites and improved the compressive strength during the initial stage of hydration. In addition, the micropore structure was improved by the pozzolanic reaction of NS and SF, thereby increasing the compressive strength during the middle stage of hydration. [ABSTRACT FROM AUTHOR]

Common scab disease in potatoes is caused by several Streptomyces spp. Although this disease does not affect the yield, it severely affects the marketability. Despite the implementation of many control strategies, efficient methods are still under debate owing to difficulty of usage, high-cost, ineffective, and non-persistence. Therefore, biological control methods are an attractive choice, especially in the field of organic potatoes. We investigated new antagonistic and endophytic Streptomyces sp. from medicinal plants. When this Streptomyces sp. strain 503 was co-cultured with a pathogen, it inhibited the production of spores or aerial mycelium of the pathogen, and the mycelial fragmentation was observed under a scanning electron microscope. In addition, strain 503 could completely inhibit the mycelia growth when the pathogen was introduced 3 days later. Strain 503 was identified as S. flavovirens, which is known to produce mureidomycin based on 16S rRNA gene sequences. Mureidomycin is a bacterial peptidoglycan synthesis inhibitor, and thus, strain 503 has a role in arresting pathogen growth and causing cell burst by inhibiting peptidoglycan synthesis. Furthermore, we confirmed the endophytic activity using a mCherry-tagged strain in the interior of plant stems and roots. In conclusion, because of its mode of action against pathogen and its ability as an endophyte, strain 503 could be a potential environment-friendly biocontrol agent in potato fields against common scab disease. [ABSTRACT FROM AUTHOR]

The epithelial–mesenchymal transition (EMT) is a differentiation process associated with fibrogenesis in diabetic nephropathy (DN). Lysophosphatidic acid (LPA) is a small, naturally occurring glycerophospholipid implicated in the pathogenesis of DN. In this study, we investigated the role of LPA/LPAR1 signaling in the EMT of tubular cells as well as the underlying mechanisms. We observed a decrease in E-cadherin and an increase in vimentin expression levels in the kidney tubules of diabetic db/db mice, and treatment with ki16425 (LPAR1/3 inhibitor) inhibited the expression of these EMT markers. Ki16425 treatment also decreased the expression levels of the fibrotic factors fibronectin and alpha-smooth muscle actin (α-SMA) in db/db mice. Similarly, we found that LPA decreased E-cadherin expression and increased vimentin expression in HK-2 cells, which was reversed by treatment with ki16425 or AM095 (LPAR1 inhibitor). In addition, the expression levels of fibronectin and α-SMA were increased by LPA, and this effect was reversed by treatment with ki16425 and AM095 or by LPAR1 knockdown. Moreover, LPA induced the expression of the transcription factor, Krüppel-like factor 5 (KLF5), which was decreased by AM095 treatment or LPAR1 knockdown. The expression levels of EMT markers and fibrotic factors induced by LPA were decreased upon KLF5 knockdown in HK-2 cells. Inhibition of the extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and serine-threonine kinase (AKT) pathways decreased LPA-induced expression of KLF5 and EMT markers. In conclusion, these data suggest that LPA contributes to the pathogenesis of diabetic nephropathy by inducing EMT and renal tubular fibrosis via regulation of KLF5 through the LPAR1. [ABSTRACT FROM AUTHOR]

Concrete structures are constructed in various geographical environments and climates, and frequently fail to fulfill their original functions over time due to issues such as aging and damage. Research on concrete structure repair materials is being conducted to solve these problems. This study evaluated the durability of a repair material composed of ultra-rapid hardening cement, styrene–butadiene (SB) latex polymer, and wollastonite mineral fiber. The performance targets were as follows: compressive strength of 20 MPa at 1 day of age and 45 MPa at 28 days of age, chloride ion charge passed of less than 1000 Coulombs, carbonation depth of 20 mm or less, and resistance to repeated freezing and thawing (relative dynamic modulus of elasticity) of 80% or more. The ultra-rapid hardening cement:silica sand ratio of 1:1.5 was the experimental variable, and the unit weight of each material in the mix proportion was determined to satisfy the flow requirement of 200 ± 5 mm. This flow ensured sufficient fluidity for spraying, which is the most widely used method for applying repair material. Wollastonite mineral fiber and SB latex polymer were added at 3% and 5% of the unit weight of the binder, respectively. The mechanical property of the repair material was evaluated through compressive strength, and durability was evaluated through chloride ion penetration, alkali resistance, resistance to carbonation, water absorption, and repeated freezing and thawing tests. The compressive strength satisfied both target values, regardless of the addition of SB latex polymer and wollastonite mineral fiber. The chloride ion penetration test, which was used as an indicator of durability, showed that mixtures without SB latex and wollastonite mineral fiber were not satisfied the target charge passed of 1000 Coulombs, while mixtures with latex and mineral fiber reached the target value. Notably, the co-addition of latex and wollastonite fiber showed the highest resistance to chloride ion penetration, alkali ion, carbonation, repeated freezing and thawing, and the least absorption. The results confirmed that the durability of the repair material based on ultra-rapid hardening cement was most effectively improved by the co-addition of SB latex polymer and wollastonite mineral fiber. [ABSTRACT FROM AUTHOR]

• β-Ga 2 O 3 FinFET. • Low-Frequency Noise. • Spatial Distribution of Trap States. • Positive-Bias Stress. The reliability of a β -Ga 2 O 3 thin-film field-effect transistor is investigated under positive-bias stress (PBS). The transistor has a tri-gate structure with a gate dielectric of Al 2 O 3. By characterizing low-frequency noise (LFN), the spatial distribution of trap in the gate dielectric was quantitatively extracted. The measured power spectral density (PSD) followed a 1/f-shape due to trapping and de-trapping of the channel carriers to and from the gate dielectric. Notably, the vertical distribution of the traps perpendicular to the interface of β -Ga 2 O 3 and Al 2 O 3 was mapped [ABSTRACT FROM AUTHOR]

Citrate-capped silver nanoparticles (Ag@Cit NPs) were synthesized by a simple plasma-assisted reduction method. Homogenous colloidal Ag@Cit NPs solutions were produced by treating a A g N O 3 -trisodium citrate-deionized water with an atmospheric-pressure argon plasma jet. The plasma-synthesized Ag@Cit NPs exhibited quasi-spherical shape with an average particle diameter of about 5.9−7.5 nm, and their absorption spectra showed surface plasmon resonance peaks at approximately 406 nm. The amount of Ag@Cit NPs increased in a plasma exposure duration-dependent manner. Plasma synthesis of Ag@Cit NPs was more effective in the 8.5 cm plume jet than in the shorter and longer plume jets. A larger amount of Ag@Cit NPs were produced from the 8.5 cm plume jet with a higher pH and a larger number of aqua electrons, indicating that the synergetic effect between plasma electrons and citrate plays an important role in the plasma synthesis of Ag@Cit NPs. Plasma-assisted citrate reduction facilitates the synthesis of Ag@Cit NPs, and citrate-capped nanoparticles are stabilized in an aqueous solution due to their repulsive force. Next, we demonstrated that plasma-synthesized Ag@Cit NPs exhibited a significant degradation of methylene blue dye. [ABSTRACT FROM AUTHOR]

In this paper, a new two-step joint optimization approach based on the asynchronous subregion optimization method is proposed for training a pipeline model composed of two different models. The first-step processing of the proposed joint optimization approach trains the front-end model only, and the second-step processing trains all the parameters of the combined model together. In the asynchronous subregion optimization method, the first-step processing only supports the goal of the front-end model. However, the first-step processing of the proposed approach works with a new loss function to make the front-end model support the goal of the back-end model. The proposed optimization approach was applied, here, to a pipeline composed of a deep complex convolutional recurrent network (DCCRN)-based speech enhancement model and a conformer-transducer-based ASR model as a front-end and a back-end, respectively. Then, the performance of the proposed two-step joint optimization approach was evaluated on the LibriSpeech automatic speech recognition (ASR) corpus in noisy environments by measuring the character error rate (CER) and word error rate (WER). In addition, an ablation study was carried out to examine the effectiveness of the proposed optimization approach on each of the processing blocks in the conformer-transducer ASR model. Consequently, it was shown from the ablation study that the conformer-transducer-based ASR model with the joint network trained only by the proposed optimization approach achieved the lowest average CER and WER. Moreover, the proposed optimization approach reduced the average CER and WER on the Test-Noisy dataset under matched noise conditions by 0.30% and 0.48%, respectively, compared to the approach of separate optimization of speech enhancement and ASR. Compared to the conventional two-step joint optimization approach, the proposed optimization approach provided average CER and WER reductions of 0.22% and 0.31%, respectively. Moreover, it was revealed that the proposed optimization approach achieved a lower average CER and WER, by 0.32% and 0.43%, respectively, than the conventional optimization approach under mismatched noise conditions. [ABSTRACT FROM AUTHOR]

Li metal is considered the most attractive anode material for high‐energy Li batteries. However, the uncontrollable growth of Li dendrites and severe volume changes during Li plating and stripping inhibit the practical application of Li metal anodes. Herein, a synergistic strategy is developed not only to suppress Li dendrite growth but also to withstand repeated volume changes during long‐term cycling. Specifically, mechanically resilient graphene assembly microspheres with interlocked Ni/N‐doped lithiophilic graphene nanostructures grown in situ are developed as stable 3D graphene hosts for Li‐metal anodes. Importantly, the approach provides a novel strategy to control radial distribution of lithiophilic Ni nanocatalysts in the graphene assembly. These 3D graphene hosts can repeatedly guide the uniform deposition of Li owing to the high lithiophilicity of Ni nanocatalysts and the N‐doped graphene nanostructures. Furthermore, graphene nanoshell forms in situ between the graphene layers in the inner part of the graphene assembly, creating strong contacts between rGO layers and providing the 3D graphene host with high structural integrity. Notably, the approach emphasizes mechanical resilience of the 3D graphene host, which retains its initial morphology after repeated Li plating/stripping cycles. Consequently, the 3D graphene host maintains a highly stable coulombic efficiency of 99% over 500 cycles. [ABSTRACT FROM AUTHOR]

Research on the effects of different fiber types and levels on infection with Brachyspira hyodysenteriae on growth performance and nutrients digestibility in pigs is scarce. The objective of the current study was to investigate the effects of infection with B. hyodysenteriae when feeding diets varying in soluble and insoluble dietary fiber (DF) on the expression of swine dysentery, growth performance, and digestibility of organic matter (OM) nutrients. A total of 96 growing pigs (26.9 ± 2.5 kg) were used for the experiment and divided into six blocks. The growing pigs were fed one of four diets for 12 wk: low fiber (LF), high fiber (HF), high soluble fiber (HS), and high insoluble fiber (HI). After 2 wk, half of the pigs were inoculated with B. hyodysenteriae. Half of the pigs in each group were euthanized at week 6 for the measurement of the apparent digestibility at the ileum, cecum, colon, and total tract. The remaining pigs were maintained to observe and analyze the clinical expression of fecal score and excretion of B. hyodysenteriae , growth performance, and total tract digestibility up to 12 wk. In the current study, the experimental diets did not influence the expression of infection in the pigs. The body weight and average daily gain (ADG) were in line with the results of clinical expression from week 4 to 6. However, the ADG of the infected pigs started to recover from week 6 (P < 0.05) and then recovered from week 8 to 12 (P < 0.05). The infection with B. hyodysenteriae did not impair apparent ileal digestibility (AID ; P > 0.05), whereas the apparent digestibility of OM, total non-starch polysaccharide, non-cellulosic polysaccharide, and cellulose in the cecum of the infected pigs was higher than non-infected pigs (P < 0.05). The apparent colonic digestibility of ash and nitrogen was higher in non-infected pigs than in infected pigs (P < 0.05). The pigs fed the LF diet had a higher digestibility in all segments of the intestinal tract, whereas the HS diet had the lowest AID but higher or similar to the LF diet in the cecum, colon, and the total tract (P < 0.05). The pigs fed the HF and HI diets, with a high proportion of insoluble fiber, had a lower digestibility in the hindgut than the other two diets (P < 0.05). In conclusion, the infection with B. hyodysenteriae negatively influenced clinical signs of swine dysentery and growth performance but did not impair AID, and neither soluble nor insoluble DF influenced the expression of the infection. [ABSTRACT FROM AUTHOR]

Mechanical metamaterials and phononic crystals enable localizing, focusing, and guiding of elastic or acoustic waves in various ways. Here, we describe the physical mechanisms underpinning wave manipulation and then review the most recent energy harvesting methods for converting localized mechanical wave energy to useable electrical energy. Due to the exceptional wave-matter interactions enabled by the man-made structures, energy is collected more efficiently than through conventional methods. Artificially designed mechanical structures are versatile, especially when used in renewable and ecologically-benign energy transformation, and have a wide array of potential applications. Judicious design of metamaterials and phononic crystals permits the realization of novel localization and wave-guiding properties. Here, recent developments and strategies for applying these structures to piezoelectric energy harvesting are reviewed. [ABSTRACT FROM AUTHOR]

• The stoichiometry of BNT based ceramics was shown to be achieved by intentionally introduced Na deficiency. • The origin of the exponentially increasing dielectric loss in BNT at elevated temperatures was identified. • The kinetically frozen-in oxygen vacancies are shown to be effectively removed by a thermal annealing at and above 700 ℃. Dielectrics for automobile applications generally require high temperature reliability. Bi 1/2 Na 1/2 TiO 3 -based materials are excellent high-temperature dielectric candidates with relatively large temperature-insensitive dielectric responses and a maximum dielectric permittivity temperature as high as 300 °C. However, they suffer from a high dielectric loss that increases exponentially above 200 °C due to ionic conduction from thermally activated oxygen vacancy migration. Here, we demonstrate that the impact of ionic conduction on dielectric loss can be effectively suppressed by introducing a sodium deficiency and thermal annealing An appropriate combination of both treatments elevated the temperature insensitivity of the dielectric loss up to ∼ 300 °C. A systematic investigation using impedance spectroscopy correlated with microstructure analysis revealed that the sodium deficiency and thermal annealing affected the mobile oxygen vacancy concentration differently. [ABSTRACT FROM AUTHOR]

The applicability of piezoelectric energy harvesting is increasingly investigated in the field of renewable energy. In improving harvester efficiency, manipulating elastic waves through a geometric configuration as well as upgrading harvester elements is important. Periodic structures, such as phononic crystals and metamaterials, are extensively employed to control elastic waves and enhance harvesting performance, particularly in terms of wave localization and focusing. In this study, we propose a double-focusing flexural energy harvesting platform consisting of a gradient-index lens and elastic Bragg mirror. Based on the design process, the frequency and time response of the harvesting platform are analyzed. The results indicate that the output voltage and power calculated at 1800 Ω are 7.9 and 62 times higher than those observed in the bare plate, respectively. Even when compared to the existing gradient-index system, they are 1.5 and 2.3 times higher, respectively. These findings can facilitate the usage of periodic structures as geometric stimuli to significantly enhance harvesting performance. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy is currently treated by highly invasive repeated therapeutic injections and surgical interventions without complete vision recovery. Here, a noninvasive smart wireless far red/near‐infrared (NIR) light emitting contact lens developed successfully for the repeated treatment of diabetic retinopathy with significantly improved compliance. A far red/NIR light emitting diode (LED) is connected with an application‐specific integrated circuit chip, wireless power, and communication systems on a PET film, which is embedded in a silicone elastomer contact lens by thermal crosslinking. After in vitro characterization, it is confirmed that the retinal vascular hyper‐permeability induced by diabetic retinopathy in rabbits is reduced to a statistically significant level by simply repeated wearing of smart far red/NIR LED contact lens for 8 weeks with 120 µW light irradiation for 15 min thrice a week. Histological analysis exhibits the safety and feasibility of LED contact lenses for treating diabetic retinopathy. This platform technology for smart LED contact lens would be harnessed for various biomedical photonic applications. [ABSTRACT FROM AUTHOR]

The macrosymmetry of (011)-oriented nominally rhombohedral relaxor-PbTiO3 single crystals poled along the [011] direction is investigated using the impedance spectroscopy method. Contrary to the common belief on the mm2 macrosymmetry, we find that the mm2 macrosymmetry significantly underestimates the electromechanical coupling of the ZXt 45 ° -cut transverse extension specimen by about 10%. We show that the underestimated electromechanical coupling can be corrected by assigning a lower symmetry of 2, i.e., an average monoclinic symmetry. The validity of the newly assigned macrosymmetry and the presence of non-regular phases presumably responsible for the apparent loss of mirror symmetry are confirmed by radial strain and thermally stimulated depolarization measurements, respectively. [ABSTRACT FROM AUTHOR]

Given a sequence of epidemic events, can a single epidemic model capture its dynamics during the entire period? How should we divide the sequence into segments to better capture the dynamics? Throughout human history, infectious diseases (e.g., the Black Death and COVID-19) have been serious threats. Consequently, understanding and forecasting the evolving patterns of epidemic events are critical for prevention and decision making. To this end, epidemic models based on ordinary differential equations (ODEs), which effectively describe dynamic systems in many fields, have been employed. However, a single epidemic model is not enough to capture long-term dynamics of epidemic events especially when the dynamics heavily depend on external factors (e.g., lockdown and the capability to perform tests). In this work, we demonstrate that properly dividing the event sequence regarding COVID-19 (specifically, the numbers of active cases, recoveries, and deaths) into multiple segments and fitting a simple epidemic model to each segment leads to a better fit with fewer parameters than fitting a complex model to the entire sequence. Moreover, we propose a methodology for balancing the number of segments and the complexity of epidemic models, based on the Minimum Description Length principle. Our methodology is (a) Automatic: not requiring any user-defined parameters, (b) Model-agnostic: applicable to any ODE-based epidemic models, and (c) Effective: effectively describing and forecasting the spread of COVID-19 in 70 countries. [ABSTRACT FROM AUTHOR]

In this study, the high ferroelectric hysteresis loss of (Pb 0 · 93 La 0.07)(Zr 0 · 82 Ti 0.18)O 3 (PLZT 7/82/18) antiferroelectric (AFE) ceramics was reduced by employing a combinatorial approach of Mn acceptor doping followed by thick film fabrication via an aerosol deposition (AD) process. The grains of the as-deposited PLZT 7/82/18 AFE AD thick films were grown by thermal annealing at 550 °C to enhance their electrical properties. Investigation of the electrical properties revealed that Mn-doping results in improved dielectric and ferroelectric properties, increased dielectric breakdown strength (DBS), and energy-storage properties. The Mn-doped PLZT AFE AD films possess a frequency-independent high dielectric constant (ε r ≈ 660) with low dielectric loss (tan δ ≈ 0.0146), making them suitable candidates for storage capacitor applications. The bipolar and unipolar polarization vs. electric field (P-E) hysteresis loops of PLZT 7/82/18 AFE AD thick films were found to be slimmer than those of their bulk form (double hysteresis) with significantly reduced ferroelectric hysteresis loss, which is attributed to the AD-induced mixed grain structure. The Mn-doped PLZT 7/82/18 AFE AD thick films exhibited a low remnant polarization (P r ≈ 9.22 μC/cm2) at a high applied electric field (~2750 kV/cm). The energy-storage density and energy efficiency of the Mn-doped PLZT AFE AD thick films were calculated from unipolar P-E hysteresis loops and found to be ~38.33 J/cm3 and ~74%, respectively. [ABSTRACT FROM AUTHOR]

Solar thermoelectric (TE) generators may potentially provide a viable alternative to photovoltaic devices for producing electrical energy from renewable sources. In this approach, the conversion of solar radiation into heat is essential to enhance the performance of TE devices, which necessitates the development of efficient solar light absorbers. Metal nanoparticles (NPs) have gained much attention in this regard because they can convert light into heat via plasmon‐mediated photothermal effects. In this study, porous nanocomposites comprising polydimethylsiloxane (PDMS) and Au NPs are prepared. In the PDMS/Au composites, the narrow extinction spectrum of Au NPs is extended over longer wavelengths by plasmonic hybridization to promote the light absorption property of the NPs. In addition, the porous structure induces strong scattering of incident light, which further enhances the absorption efficiency of the Au NPs. Consequently, the plasmon‐mediated photothermal effects of Au NPs are noticeably enhanced and increased the temperature of the PDMS/Au composites to as high as 75.7 °C under artificial solar radiation, compared to 42.1 °C without the Au NPs. By applying the PDMS/Au composites to commercial TE devices, the electrical performance of the TE devices is enhanced by approximately threefold. [ABSTRACT FROM AUTHOR]

The lymph node status is the most important prognostic factor for endometrial cancer. This study aimed to assess whether sentinel lymph node mapping (SLNM) is applicable in endometrial cancer. A retrospective review of patients with endometrial cancer who were diagnosed and treated in Asan Medical Centre from September 2015 to December 2017 was conducted. One hundred patients underwent robotic (da Vinci®) or laparoscopic surgical treatment, including SLNM with indocyanine green (ICG) fluorescence detection using the Firefly® and NIR/ICG systems. At least one lymph node area was observed in 100% of SLNM cases. Sentinel node detection and frozen biopsy were performed in all cases, and all patients with metastasis were found on SLNM. The sensitivity and negative predictive value were both 100% in the patient-by-patient and station-by-station analyses. SLNM appears to be a feasible method to reduce the morbidity and increase the detection rate in early-stage endometrial carcinoma. What is already known on this subject? There are studies that it is safe to diagnose the possibility of lymph node metastasis through sentinel lymph node mapping in endometrial cancer. What do the results of this study add? In this study, it is shown that the accuracy of sentinel lymph node mapping is 100% accurate. What are the implications of these findings for clinical practise and/or further research? Therefore, total lymphadenectomy will not be necessary for the future. [ABSTRACT FROM AUTHOR]

Summary: The preservation of King oyster mushrooms (KOMs) during storage remains a significant challenge due to their susceptibility to microbial spoilage, browning and quality degradation. This study explores the efficacy of electron beam irradiation (EBI) as a novel preservation technique for KOMs, targeting these specific storage issues. Employing a range of detection techniques, we evaluated the impact of EBI on microbial contamination, essential qualities and the browning of KOMs. Our findings reveal that EBI significantly reduces microbial contamination, including total aerobic bacteria and Pseudomonas spp., effectively inhibiting pathogenic spoilage and the formation of browning lesions. The treatment successfully preserved the moisture content, water activity and minimised weight loss, thus maintaining the mushrooms' textural and visual quality. Notably, doses of EBI up to 2 kGy did not adversely affect the firmness of KOMs. Additionally, we determined that photostimulated luminescence and thermoluminescence are effective methods for detecting EBI treatment in KOMs, whereas electron spin resonance proved unsuitable due to the lack of a distinctive irradiation signal in high‐moisture content foods. These findings contribute to the development of an efficient preservation technique for perishable KOMs, offering potential applicability in the food industry. [ABSTRACT FROM AUTHOR]

To understand the killing mechanism of fungal spores by plasma treatment, the optical, structural, and biological properties of the insect pathogenic fungus Cordyceps bassiana spores were studied. A nonthermal atmospheric-pressure plasma jet (APPJ) was used to treat the spores in aqueous solution. Optical emission spectra of the APPJ acquired in air indicated emission peaks corresponding to hydroxyl radicals and atomic oxygen. When the APPJ entered the aqueous solution, additional reactive species were derived from the interaction of plasma radicals with the aqueous solution. Fluorescence and absorption spectroscopy confirmed the generation of hydroxyl radicals and hydrogen peroxide in the plasma-activated water (PAW). Spore counting showed that plasma treatment significantly reduced spore viability. Absorption spectroscopy, circular dichroism (CD) spectroscopy, and agarose gel electrophoresis of the DNA extracted from plasma-treated spores showed a reduction in spore DNA content. The magnitude of the dip in the CD spectrum was lower in the plasma-treated spores than in the control, indicating that plasma treatment causes structural modifications and/or damage to cellular components. Tryptophan fluorescence intensity was lower in the plasma-treated spores than in the control, suggesting that plasma treatment modified cell wall proteins. Changes in spore viability and DNA content were attributed to structural modification of the cell wall by reactive species coming from the APPJ and the PAW. Our results provided evidence that the plasma radicals and the derived reactive species play critical roles in fungal spore inactivation. [ABSTRACT FROM AUTHOR]

Backgrounds and purpose: Radiation therapy is an important mode of treatment for patients with head and neck cancers, but some associated complications can reduce the quality of life. We investigated whether N-acetylcysteine inhalation therapy improved the quality of life of such patients. Materials and methods: We designed a prospective, non-randomized controlled multi-center study involving 10 institutions. We enrolled 120 patients (80 in the experimental group and 40 in the control group). Patients in the experimental group inhaled nebulized liquid N-acetylcysteine (2400 mg daily) for 8 weeks from the start of radiation therapy. Quality of life was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire H&N 35. Results: N-acetylcysteine inhalation was not associated with any side effect or discomfort. The reduction in painkiller use from the end of N-acetylcysteine inhalation therapy to the 1-month follow-up was greater in the experimental group than in the control group (P = 0.014). Dry mouth symptoms also improved significantly in the experimental group (P = 0.019). Conclusion: N-acetylcysteine inhalation improves the quality of life of patients with head and neck cancers who are receiving radiation therapy, without any specific side effect. [ABSTRACT FROM AUTHOR]

Purpose: Aneurysmal subarachnoid hemorrhage (SAH) can chronically affect cognitive function, and SAH has been suggested to result in regional brain damage. This study aimed to assess regional structural damage according to initial clinical status including SAH volume. Methods: A total of 63 consecutive patients treated with coil embolization for intracranial aneurysms for more than 6 months were enrolled. Of these, 35 patients had SAH and 28 patients who were treated for unruptured aneurysms served as controls. Volumetric T1-weighted images were acquired with 1 mm isotropic voxel. The SAH volume was measured semi-automatically from the initial brain CT scan. Voxel-based group comparison was conducted to assess regional gray matter volume (GMV) changes. Voxel-based multiple regression was conducted to analyze regional GMV change and SAH volume. The clinical factors (Glasgow Coma Scale (GCS), SAH volume, systolic blood pressure, and serum laboratory findings) associated with regional GMV were also analyzed by using multiple regression. Results: The SAH group had significantly lower GMV in the left hippocampus and higher GMV in the visual cortex than controls (Alphasim-corrected p < 0.05, voxel level of p < 0.001). The GMV of the bilateral hippocampi, thalami, and left medial orbital gyrus was negatively correlated with the initial SAH volume (FDR-corrected p < 0.05). SAH volume and GCS were associated with the hippocampal GMV in multiple regression (p < 0.05). Conclusions: Chronic regional GMV change after SAH was related to the severity of initial clinical status including SAH volume. This finding supports the pathophysiological hypothesis of SAH-induced microstructural brain injury. [ABSTRACT FROM AUTHOR]

Low-frequency noise (LFN) characteristics under OFF-state stress (OSS), which degrade device performance, were investigated in n-channel MOSFETs. The power spectral density (PSD) was analyzed by investigating the LFN and the border traps located in the gate oxide were extracted along a depth direction perpendicular to the silicon (Si) channel surface. The holes generated by band-to-band tunneling (BTBT) in the overlap region between a drain and a gate were found to be more detrimental to device performance than channel hot-carriers created by impact ionization. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to investigate residual rotation of patients with forearm amputation and the contribution of involved muscle to residual rotation.Methods: Testing was performed using five fresh-frozen cadaveric specimens prepared by isolating muscles involved in forearm rotation. Amputation was implemented at 25 cm (wrist disarticulation), 18 cm, or 10 cm from the tip of olecranon. Supination and pronation in the amputation stump were simulated with traction of involved muscle (supinator, biceps brachii, pronator teres, pronator quadratus) using an electric actuator. The degree of rotation was examined at 30°, 60°, 90°, and 120° in flexion of elbow.Results: Average rotation of 25 cm forearm stump was 148° (SD: 23.1). The rotation was decreased to 117.5° (SD: 26.6) at 18 cm forearm stump. It was further decreased to 63° (SD 31.5) at 10 cm forearm stump. Tendency of disorganized rotation was observed in close proximity of the amputation site to the elbow. Full residual pronation was achieved with traction of each pronator teres and pronator quadratus. Although traction of supinator could implement residual supination, the contribution of biceps brachii ranged from 4 to 88% according to the degree of flexion.Conclusions: Close proximity of the amputation site to the elbow decreased the residual rotation significantly compared to residual rotation of wrist disarticulation. The preservation of pronosupination was 80% at 18 cm forearm stump. Although the pronator teres and the pronator quadratus could make a full residual pronation separately, the supinator was essential to a residual supination. [ABSTRACT FROM AUTHOR]

The gate-induced drain leakage (GIDL) current is one of the major leakage sources in a dynamic random-access memory (DRAM) cell transistor. In addition to band-to-band tunneling (BTBT), which causes GIDL in the gate-to-drain overlap region, the generation of interface traps in the gate dielectric increases the GIDL current by trap-assisted two-step tunneling (TATT). In this article, the influence of OFF-state stress on the generation of the interface traps, which deteriorates GIDL, was quantitatively analyzed with charge pumping (CP) characterization method in buried-channel array transistors (BCATs) for DRAM cells. The applied stress increased the GIDL current while simultaneously degrading device performance including such as transconductance (gm) and ON-state current (ION), due to the generation of the interface traps. By using the CP characterization, the interface traps were spatially profiled along the gate-to-drain overlap region in the junction. Trap distribution inside the energy bandgap was also characterized. [ABSTRACT FROM AUTHOR]

Homogeneously dispersed Mo 2 C nanoparticles onto nitrogen-doped carbon nanotube - reduced graphene oxide support (Mo 2 C/CNT-RGO) were prepared by a modified urea glass route. Simply heating an ethanol slurry of MoCl 5 , urea, CNT, and graphene oxide at 750 °C under nitrogen atmosphere uniformly distributed 8 nm Mo 2 C nanoparticles in the nitrogen-doped CNT-RGO support. The resultant Mo 2 C/CNT-RGO exhibited markedly improved electrochemical performance for hydrogen evolution reaction (HER) compared to similarly prepared Mo 2 C/CNT, Mo 2 C/RGO, and bare Mo 2 C. Enhanced Mo 2 C/CNT-RGO performance could originate from the synergy between Mo 2 C nanoparticles with high HER activity and N-doped CNT-RGO support providing large surface area and high electrical conductivity. Image 1 • A simple synthesis of nanostructured Mo 2 C/CNT-RGO composite is proposed. • Carbide formation, GO reduction, and N-doping are simultaneously achieved. • Mo 2 C/CNT-RGO is used as a catalyst for hydrogen evolution reaction (HER). • Mo 2 C/CNT-RGO shows high activity and stability for HER under alkaline media. • Unique CNT-RGO heterostructure helps to enhance the HER activity. [ABSTRACT FROM AUTHOR]

Relaxor-PbTiO 3 piezoelectric single crystals have been of a great interest, since the discovery of ultrahigh piezoresponse demonstrated in <001> -oriented crystals of the composition at the rhombohedral side of morphotropic phase boundary. It has been proposed that the exceptionally large piezoelectric properties should originate from an electric-field-induced polarization rotation that involves a reversible phase transformation between rhombohedral and tetragonal via monoclinic symmetry. However, this commonly accepted polarization rotation mechanism has its limit in explaining still the excellent piezoelectricity even at a small excitation field far below the coercive field. Here, we show by a comparative study using single crystals from two distinct processing techniques, the polarization rotation has, if ever, little influence on the strain properties of <001 > -oriented rhombohedral relaxor-PbTiO 3 single crystals. Instead, they may come from a reversible shear-mode piezoelectric contribution from electric-field-susceptible 'symmetry-bridging' unit-cell-level phases, the polarization direction of which spans monoclinic symmetry. [ABSTRACT FROM AUTHOR]

The linear and nonlinear optical properties of one-dimensional photonic crystals containing ZnO defects were studied by linear absorption spectroscopy and the femtosecond Z-scan technique. Photonic crystals containing ZnO defects, (Ta2O5/SiO2)5/ZnO/(SiO2/Ta2O5)5, were prepared using electron-beam deposition and magnetron sputtering. The transmission spectra of these photonic crystals revealed a defect mode resonance and a broad photonic band gap. The observed transmission spectra could be described by applying the optical transfer matrix formalism to the multilayer structure. When compared with the Z-scan curve of the ZnO film, that of the resonant photonic crystal exhibited a larger transmittance dip. The enhancement of the nonlinear absorption in the resonant photonic crystal is due to the strong confinement of the optical field. [ABSTRACT FROM AUTHOR]

• A trampoline metamaterial is designed for realizing multiband energy localization and harvesting. • Bragg-scattering and local resonance is exploited to control the bandgap at high and low frequencies. • Flexural wave energy is localized through defect modes by breaking the periodicity. • High-performance piezoelectric energy harvesting is achieved at multi-frequency range. In this study, we investigate high-performance piezoelectric energy harvesting at multiband frequencies. Previous harvesting platforms were limited to a high-frequency range and exhibited poor electrical performance. Our proposed piezoelectric energy-harvesting platform, which is based on a periodically arranged trampoline metamaterial, exhibits a remarkable electrical output at both low and high frequencies. The proposed harvesting platform broadens the bandgap induced by Bragg scattering in the high-frequency range, and the local resonance is critical in opening a wide bandgap in the low-frequency range. By breaking the periodicity, we generate multiband defect states for flexural wave trapping under fundamental physical phenomena. We experimentally demonstrate flexural wave localization in the defect cavity, while a confined wave is converted into high-performing electrical energy using a piezoelectric element. We measure 1.37 V and 4.05 V as output voltage, and 24.4 μ W and 1.28 m W as output power at the 1st and 2nd defect modes, respectively, which are 188% and 400% compared with the bare plate. Our high-power energy-harvesting platform has potential applications as a renewable and sustainable energy source in various fields, such as structural health monitoring, signal processing, and sensors. [ABSTRACT FROM AUTHOR]

The most important issue in the processing of nanoscale metal powders is whether the metal nanopowder can be fully consolidated into ultra‐fine‐ or nano‐grained powder metallurgy parts by pressureless sintering. This paper focuses on the sintering behavior of bimodal iron (Fe) nanopowder agglomerates by considering their microstructure and densification kinetics. During the sintering, bimodal Fe nanopowder compacts underwent discontinuous shrinkage behavior until they neared full density. Three contributions to the sintering mechanisms, asymmetric sintering, densification enhancement, and grain growth inhibition, are presented in relation to the effect of bimodal nanopowder structure. Smaller nanoparticles in the bimodal nanopowders, which are predominantly present at the boundaries and interstitial spaces of larger nanoparticles, are responsible for the three mechanisms stated above. This result is strongly supported by the apparent activation energy values ranging from 48.2 to 90.6 kJ/mol, which correspond to the energy for grain‐boundary diffusion in Fe. The experimental results of this study show that bimodal nanopowder agglomerates can be used to produce full density nano‐grained powder metallurgical parts by pressureless sintering. [ABSTRACT FROM AUTHOR]

Abstract In this study, we intend to revisit oxide/nanocarbon composites for a systematic study of oxide particle size, chemical bonding between oxide and carbon, electrical conductivity and ion transport in the composites on the electrochemical properties of NaTi 2 (PO 4) 3 @nanocarbon microsphere composites prepared using zero-dimensional carbon black, one-dimensional carbon nanotubes, and two-dimensional graphene as anode materials for high-rate sodium-ion batteries. In the solution-based synthesis of the composites, oxide precursor nanoparticles deposited on nanocarbons are converted into final oxide nanoparticles through heat treatment. We demonstrate that growth of the NaTi 2 (PO 4) 3 particles in the NaTi 2 (PO 4) 3 @nanocarbon composites occurs during heat treatment when the concentration of oxygen functional groups per unit specific area of nanocarbons is high. Growth of oxide precursor nanoparticles is observed for carbon black with a high concentration of oxygen functional groups during heat treatment owing to the proximity between precursor particles. On the other hand, growth of precursor nanoparticles is effectively prevented for carbon nanotubes and graphene with a low concentration of oxygen functional groups. Rate capability increases in the order of NaTi 2 (PO 4) 3 @carbon black < NaTi 2 (PO 4) 3 @graphene < NaTi 2 (PO 4) 3 @carbon nanotubes mainly due to the smaller sizes of oxide particles and more efficient Na+ transport across carbon nanotubes compared to other nanocarbons. Highlights • Comprehensive investigation of nanocarbons with different dimensions in the composite. • Importance to concentration of oxygen functional groups of nanocarbons. • Improved rate capability by small sizes of oxide particles in the composite. • High rate capability by Na+ transport across nanocarbons in the composite. [ABSTRACT FROM AUTHOR]

An asymmetric A-π-D-π-A' organic dye (dye1) combining a red D − π−A dye (D35) and a blue D − π−A' dye (DB) on each side of a triphenylamine (TPA) was designed, and a theoretical study was conducted to determine its utility as a dye-sensitized solar cell (DSSC). To gain insight into the factors responsible for the photovoltaic performance of the dye, density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations for the dye were compared with those of reference dyes (D35 and DB). The absorption spectrum of the dyes differed due to different energy levels of the molecular orbitals (MOs) of each dye and intramolecular charge transfer (ICT). The results show that the heteroleptic di-anchoring dye1 had comparable photovoltaic properties to those of D35 and DB combined. As compared with the dyes containing single acceptors, the asymmetric organic dye containing heteroleptic dual acceptors showed competitive conversion efficiency of DSSCs, a broader absorption spectrum, and a higher molar extinction coefficient. These results indicate that dyes containing heteroleptic dual acceptors produces good photovoltaic properties for DSSCs. [ABSTRACT FROM AUTHOR]

In this paper, we present the design, fabrication, and performance evaluation of a polyimide-based flexible neural probe for the precise site stimulation and recording in the deep brain. The probe consists of five electrodes: one for stimulation, another for ground and the other three for recording electrodes. This probe is designed to be foldable, enabling easy insertion into the deep brain via temporary tungsten guide sticks. Because of its small cross-sectional area and the flexibility of the polyimide, the probe causes minimum damage to the neural tissue and does not show any evidence of serious immune reactions such as high density of macrophage or microglia. Around the simulation electrodes, an additional ground electrode prevents the stimulation of the undesired sites in the brain. To ensure we stimulate the target point specifically, for instance STh in this study, we confirm through both finite element analyses and in vitro tests. With the additional ground electrodes, we observe the leakage power decreased by about 80%. To check the performance of the probe, we demonstrate animal experiments using rats, and neural spike signals from STh in the 7-mm deep brain are successfully recorded after implantation. [ABSTRACT FROM AUTHOR]

The compaction behavior of structure-modified Fe nanopowders having agglomerates of spherical shape and a bimodal particle size distribution was investigated in terms of the particle packing and microstructure during compaction process. To fabricate the structure-modified Fe nanopowders, the spray-dried Fe 2 O 3 nanopowder was hydrogen reduced at 400, 450 and 550 °C to control the degree of particle growth in agglomerates. The compaction behavior of fabricated Fe nanopowders was investigated by two different ways. In die compaction experiments, it was found that the bimodal nanopowder reduced at 550 °C showed higher green density compared to nanopowders reduced at 400 and 450 °C over the entire range of compacting pressure. Furthermore, the compact of the bimodal nanopowder achieved a remarkable green density over 80% of theoretical density (TD) at 1000 MPa pressure without any defects due to the effective packing by filling the interstices between the large nanoparticles with small nanoparticles. The obtained density-pressure data was fitted by the Panelli and Ambrozio Filho equation to compare the densification capacity between the fabricated Fe nanopowders. To investigate the agglomerate deformation occurrence at the low pressure range, a continuous compaction experiment was conducted; the observations were explained in terms of microstructural development on the basis of the apparent yield pressure obtained from continuous densification curves. [ABSTRACT FROM AUTHOR]

[Display omitted] Ocular drug delivery and therapy systems have been extensively investigated with various methods including direct injections, eye drops and contact lenses. Nowadays, smart contact lens systems are attracting a lot of attention for ocular drug delivery and therapy due to their minimally invasive or non-invasive characteristics, highly enhanced drug permeation, high bioavailability, and on-demand drug delivery. Furthermore, smart contact lens systems can be used for direct light delivery into the eyes for biophotonic therapy replacing the use of drugs. Here, we review smart contact lens systems which can be classified into two groups of drug-eluting contact lens and ocular device contact lens. More specifically, this review covers smart contact lens systems with nanocomposite-laden systems, polymeric film-incorporated systems, micro and nanostructure systems, iontophoretic systems, electrochemical systems, and phototherapy systems for ocular drug delivery and therapy. After that, we discuss the future opportunities, challenges and perspectives of smart contact lens systems for ocular drug delivery and therapy. [ABSTRACT FROM AUTHOR]