Deposition of Crystalline GdIG Samples Using Metal Organic Decomposition Method

Fabrication of high quality ferrimagnetic insulators is an essential step for ultrafast magnonics, which utilizes antiferromagnetic exchange of the ferrimagnetic materials. In this work, we deposit high-quality GdIG thin films on a (111)-oriented GGG substrate using the Metal Organic Decomposition (MOD) method, a simple and high throughput method for depositing thin film materials. We postannealed samples at various temperatures and examined the effect on structural properties such as crystallinity and surface morphology. We found a transition in the growth mode that radically changes the morphology of the film as a function of annealing temperature and obtained an optimal annealing temperature for a uniform thin film with high crystallinity. Optimized GdIG has a high potential for spin wave applications with a low damping parameter in the order of 10(-3), which persists down to cryogenic temperatures

A scalable molecule-based magnetic thin film for spin-thermoelectric energy conversion

Spin thermoelectrics, an emerging thermoelectric technology, offers energy harvesting from waste heat with potential advantages of scalability and energy conversion efficiency, thanks to orthogonal paths for heat and charge flow. However, magnetic insulators previously used for spin thermoelectrics pose challenges for scale-up due to high temperature processing and difficulty in large-area deposition. Here, we introduce a molecule-based magnetic film for spin thermoelectric applications because it entails versatile synthetic routes in addition to weak spin-lattice interaction and low thermal conductivity. Thin films of Cr-II[Cr-III(CN)(6)], Prussian blue analogue, electrochemically deposited on Cr electrodes at room temperature show effective spin thermoelectricity. Moreover, the ferromagnetic resonance studies exhibit an extremely low Gilbert damping constant -(2.4 +/- 0.67) x10(-4), indicating low loss of heat-generated magnons. The demonstrated STE applications of a new class of magnet will pave the way for versatile recycling of ubiquitous waste heat

Design principles of noble metal-free electrocatalysts for hydrogen production in alkaline media: combining theory and experiment

Water electrolysis is a promising solution to convert renewable energy sources to hydrogen as a high-energy-density energy carrier. Although alkaline conditions extend the scope of electrocatalysts beyond precious metal-based materials to earth-abundant materials, the sluggish kinetics of cathodic and anodic reactions (hydrogen and oxygen evolution reactions, respectively) impede the development of practical electrocatalysts that do not use precious metals. This review discusses the rational design of efficient electrocatalysts by exploiting the understanding of alkaline hydrogen evolution reaction and oxygen evolution reaction mechanisms and of the electron structure–activity relationship, as achieved by combining experimental and computational approaches. The enhancement of water splitting not only deals with intrinsic catalytic activity but also includes the aspect of electrical conductivity and stability. Future perspectives to increase the synergy between theory and experiment are also proposed. Water electrolysis is a promising solution to convert renewable energy sources to hydrogen as a high-energy-density energy carrier. Although alkaline conditions extend the scope of electrocatalysts beyond precious metal-based materials to earth-abundant materials, the sluggish kinetics of cathodic and anodic reactions (hydrogen and oxygen evolution reactions, respectively) impede the development of practical electrocatalysts that do not use precious metals. This review discusses the rational design of efficient electrocatalysts by exploiting the understanding of alkaline hydrogen evolution reaction and oxygen evolution reaction mechanisms and of the electron structure–activity relationship, as achieved by combining experimental and computational approaches. The enhancement of water splitting not only deals with intrinsic catalytic activity but also includes the aspect of electrical conductivity and stability. Future perspectives to increase the synergy between theory and experiment are also proposed.11Ysciescopu

Experimental and density functional theory studies on Cu/Ba-coimpregnated γ-Al2O3 for low-temperature NO storage and adsorbent regeneration

Although the lean-NOx trap (LNT) has been used to reduce NOx emissions from diesel-powered vehicles, LNT application is limited because its performance degrades at low temperatures (e.g., during cold starting). Therefore, to enhance low-temperature NOx storage and adsorbent regeneration, γ-Al2O3 was coimpregnated with both Cu and Ba (Cu–Ba/γ-Al2O3). The experimentally measured NOx storage capacities (NSCs) and NOx storage efficiencies (NSEs) were compared. Density-functional-theory (DFT) calculations were performed to reveal the NOx storage mechanism. The Cu/Ba-coimpregnated γ-Al2O3 improved both NSC and NSE of NO storage and enhanced NSE of NO2 storage at initial stage. In addition, it desorbed NOx at lower temperatures than the conventional Ba-impregnated γ-Al2O3 (Ba/γ-Al2O3). The in-situ diffuse reflectance infrared Fourier-transform spectroscopy analysis and DFT calculations for NO storage showed that NO adsorption was superior on the Cu-compound surfaces and that stable hyponitrite was stored on the Ba-compound surfaces. In NO2 storage, Cu/Ba coimpregnation offered high preferential NO2 coverage on the CuO surface and produced the most stable ionic nitrate on the Ba-compound surfaces. The experimental and theoretical results confirmed that the Cu/Ba-coimpregnated adsorbent exhibited both superior NOx storage and adsorbent regeneration compared to the conventional Ba-containing LNT adsorbent.11Nsciescopu

Treatment of Diabetic Foot Ulcer Using Matriderm In Comparison with a Skin Graft

BackgroundFor patients with neuropathy, vasculopathy, and impairment of wound healing, treatment of a diabetic foot ulcer poses many challenges. A large number of dermal analogues have been invented in an effort to overcome these challenges. Matriderm, a dermal analogue, is made from bovine collagen and elastin. This study was conducted in order to evaluate the effectiveness of Matriderm for treatment of diabetic foot ulcers, in comparison with skin grafting.MethodsSixty patients with diabetic foot ulcer were included in this prospective study. The average age of the patients, who had type II diabetes mellitus, was 58 years old. The patients were allocated to an experimental or control group with their consents. The patients were selected with their consent for inclusion in an experimental group and a control group. Patients in the experimental group received a Matriderm appliance and a split-thickness skin graft, while those in the control group received only a split-thickness skin graft.ResultsA shorter hospitalization period (7.52 weeks) was observed in the experimental group than in the control group (9.22 weeks), and a shorter period of time (8.61 weeks) was required for complete healing, compared with the control group (12.94 weeks), with statistical significance (P<0.05). A higher elasticity ratio of the affected side to the non-affected side was observed in the experimental group, compared with the control group (P<0.01).ConclusionsMatriderm enables effective healing and improves elasticity in treatment of patients with diabetic foot ulcer

Surface Roughening Strategy for Highly Efficient Bifunctional Electrocatalyst: Combination of Atomic Layer Deposition and Anion Exchange Reaction

Electrocatalytic water splitting, which is an interface-dominated process, can be significantly accelerated by increasing the number of front-line surface active sites (N-A) of the electrocatalyst. In this study, a unique method is used for increasing the N-A by converting the smooth ultrathin atomic-layer-deposited nanoshells of the electrocatalysts into nano-roughened active shell layers using a controlled anion-exchange reaction (AER). The coarse thin nanoshells present abundant surface active sites, which are generated owing to the inherent unit-cell volume mismatch induced during the AER. Consequently, the nano-roughened electrodes accelerate the sluggish water reaction kinetics and lower the overpotentials required for the hydrogen and oxygen evolution reactions. In addition, the electronic modulation induced by the nanoshell layer at the core-nanoshell interface amplifies the local electron density, as confirmed using electrochemical analysis data and density functional theory calculations. Because of the integrity of the composite electrodes during water-splitting half-cell reactions, their durability for industrial seawater electrolysis is evaluated. The results indicate that their electrochemical activity does not change significantly after 10 days of continuous overall water splitting.11Nsciescopu

Anatomical and Functional Recovery of Neurotized Remnant Rectus Abdominis Muscle in Muscle-Sparing Pedicled Transverse Rectus Abdominis Musculocutaneous Flap

BackgroundPedicled transverse rectus abdominis musculocutaneous flaps typically sacrifice the entire muscle. In our experience, the lateral strip of the rectus abdominis muscle can be spared in an attempt to maintain function and reduce morbidity. When the intercostal nerves are injured, muscle atrophy appears with time. The severed intercostal nerve was reinserted into the remnant lateral strip of the rectus abdominis muscle to reduce muscle atrophy.MethodsThe authors retrospectively reviewed 9 neurotized cases and 10 non-neurotized cases. Abdominal computed tomography was performed to determine the area of the rectus muscles. Electromyography (EMG) was performed to check contractile function of the remnant muscle. A single investigator measured the mean areas of randomly selected locations (second lumbar spine) using ImageJ software in a series of 10 cross-sectional slices. We compared the Hounsfield unit (HU) pre- and postoperatively to evaluate regeneration quality.ResultsIn the neurotization group, 7 of 9 cases maintained the mass of remnant muscle. However, in the non-neurotization group, 8 of 10 lost their mass. The number of totally atrophied muscles in each of the two groups was significantly different (P=0.027). All of the remnant muscles showed contractile function on EMG. The 9 remaining remnant rectus abdominis muscles showed declined the HU value after surgery but also within a normal range of muscle.ConclusionsNeurotization was found to be effective in maintaining the mass of remnant muscle. Neurotized remnant muscle had contractile function on EMG and no fatty degeneration by HU value

Atomic layer deposition-triggered hierarchical core/shell stable bifunctional electrocatalysts for overall water splitting

The precise design of nanomaterials is a promising approach, but remains a challenge toward the development of highly efficient catalysts in water splitting applications. Herein, a facile three-step process to rationally design advanced NiCo2O4/MoO2@atomic layer deposition (ALD)-NiO heteronanostructure arrays on a nickel foam substrate is reported. By effective interface construction, the optimal electronic structure and coordination environment are created at the interface in the heteronanostructure, which can provide rich reaction sites and short ion diffusion paths. Notably, density functional theory calculations reveal that the MoO2@ALD-NiO nanointerface exhibits highly appropriate energetics for alkaline oxygen/hydrogen evolution reactions (OER/HER), thereby accelerating the enhancement in electrochemical activities. Benefiting from the heteronanostructure containing abundant nanointerfaces, NiCo2O4/MoO2@ALD-NiO displays remarkable HER (57.1 mV at 10 mA cm−2) and OER (372.3 mV at 100 mA cm−2) activities and excellent long-term stability in a 1 M KOH solution. This study provides new insight into the catalytic design of cost-effective electrocatalysts for future renewable energy systems.11Nsciescopu

Bio-Inspired Catecholamine-Derived Surface Modifier for Graphene-Based Organic Solar Cells

Owing to the growing interest in next-generation solar cells as a clean and renewable energy source, the demand for alternative transparent conducting electrodes (TCEs) has also increased. Although indium tin oxide (ITO) has been widely used as the standard TCE, its chemical and mechanical instabilities limit its widespread use in emerging photovoltaics. Graphene has attracted much attention as a potential alternative TCE owing to its excellent physical, optical, and electrical properties. However, owing to the inert nature of graphene with a hydrophobic surface, a significant amount of research has been devoted to resolve the nonwetting issue of charge-transporting materials on graphene. In this study, a thin layer of norepinephrine, an amphiphilic catecholamine derivative, was applied to graphene as a hydrophilic surface modifier to enable efficient surface modification without significantly decreasing the optical transmittance or the electrical conductivity. This modification allowed a commonly used hole-transporting material to be applied uniformly to the surface. Thus, the power conversion efficiency (PCE) of organic solar cells (OSCs) fabricated with this poly(norepinephrine)-coated graphene electrode was 7.93%, which is approaching close to that of the ITO-based reference device with a PCE of 8.73%. This work represents the first demonstration of an adhesive biomaterial as an efficient surface modifier for chemically inert graphene and its successful application in OSCs, which shows promise for the future development of bio-inspired graphene systems for applications to various optoelectronic devices