Electrochemical properties of yolk-shell-structured Zn-Fe-S multicomponent sulfide materials with a 1:2 Zn/Fe molar ratio.

Yolk-shell-structured Zn-Fe-S multicomponent sulfide materials with a 1:2 Zn/Fe molar ratio were prepared applying a sulfidation process to ZnFe2O4 yolk-shell powders. The Zn-Fe-S powders had mixed sphalerite (Zn,Fe)S and hexagonal FeS crystal structures. The discharge capacities of the Zn-Fe-S powders sulfidated at 350 °C at a constant current density of 500 mA g(-1) for the first, second, and fiftieth cycles were 1098, 912, and 913 mA h g(-1), respectively. The powders exhibited a high discharge capacity of 602 mA h g(-1) even at the high current density of 10 A g(-1). The synergistic effect of yolk-shell structure and multicomponent composition improved the electrochemical properties of Zn-Fe-S powders.

Enhancement of performance and sulfur resistance of Si-doped V/W/Ti using sulfation for selective catalytic reduction of NOx with ammonia.

HIGHLIGHTS: The SO2 resistance improvement factor was confirmed to form Si2+(Si-O-Ti) species.In the optimised V/SiW/TiO2 catalyst; the incoming SO2 was converted to Si(SO4).The formation of Si(SO4) increased active sites for adsorbed NH3, in the form of SO4-NH3 to improve denitrification efficiency.

A bipedicled keystone perforator island flap: Pedicle division technique with enhanced advancement potential for chronic wound coverage.

Since the first description of the keystone perforator island flap (KPIF) in 2003, several modifications have been suggested to enhance its coverage ability. However, locoregional flaps have limited its use in chronic wounds due to decreased elasticity around the defect. We investigated the use of a bipedicled KPIF (bKPIF), which covers a defect while completely elevating the median part of the flap from the fascia. A retrospective chart review of 20 consecutive patients who underwent classical type I KPIF (n = 10) or bKPIF (n = 10) reconstruction from June 2020 to December 2022 was performed. Baseline characteristics, indications, operative details, healing time, and complications were analyzed and compared between the two groups. The average defect size was 30 cm2 in type I KPIF and 36.6 cm2 in bKPIF, and an average flap size of 86.5 cm2 was covered in type I KPIF, larger than bKPIF at 73.8 cm2. The flap/defect ratio was significantly lower in the bKPIF group (p < 0.02), with an average of only 55% pedicular area. The average advancement distance in the bKPIF group was 1.85 cm (standard deviation 0.78) greater than that in the type 1 KPIF group. There was no significant difference between the groups in terms of operation time, complete healing time, and complications. All ten bKPIFs were successful without any flap necrosis. Even though the mean pedicular area in the bKPIF group was nearly half compared with that in the type I KPIF group, it was sufficient to perfuse the entire flap without any major complications. This novel technique using bKPIF has potential clinical relevance, as evidenced by the enhanced ability to cover chronic defects with severe scarring. Lateralizing the hotspots to the bilateral corners of the flap is the mechanism that facilitates this potential.

Breast Tissue Restoration after the Partial Mastectomy Using Polycaprolactone Scaffold.

As breast conserving surgery increases in the surgical treatment of breast cancer, partial mastectomy is also increasing. Polycaprolactone (PCL) is a polymer that is used as an artifact in various parts of the human body based on the biocompatibility and mechanical properties of PCL. Here, we hypothesized that a PCL scaffold can be utilized for the restoration of breast tissue after a partial mastectomy. To demonstrate the hypothesis, a PCL scaffold was fabricated by 3D printing and three types of spherical PCL scaffold including PCL scaffold, PCL scaffold with collagen, and the PCL scaffold with breast tissue fragment were implanted in the rat breast defect model. After 6 months of implantation, the restoration of breast tissue was observed in the PCL scaffold and the expression of collagen in the PCL scaffold with collagen was seen. The expression of TNF-α was significantly increased in the PCL scaffold, but the expression of IL-6 showed no significant difference in all groups. Through this, it showed the possibility of using it as a method to conveniently repair tissue defects after partial mastectomy of the human body.

Influence of Mn valence state and characteristic of TiO2 on the performance of Mn-Ti catalysts in ozone decomposition.

The effects of physicochemical properties of Mn-Ti catalysts on O3 conversion were examined. The catalysts were prepared by a wet impregnation method that gave manganese supported on various commercial sources of TiO2. The properties of the catalysts were studied using physicochemical techniques, including Brunauer-Emmett-Teller (BET) surface area analysis, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), and thermal gravimetric analysis (TGA). The O3 decomposition tests of Mn-Ti catalysts with various manganese loadings revealed that the 10 wt% manganese catalyst exhibited optimal, excellent activity. The O3 conversion and Mn valence state of the Mn-Ti catalysts were different, depending on the structure of the TiO2 source. Increasing the O/Ti surface atomic ratio in TiO2 increased the Mn3+ ratio. The Mn3+ ratio directly affected the O3 decomposition activity of the Mn-Ti catalyst. When the Mn3+ ratio was the largest, the catalyst showed the highest activity in O3 decomposition. The valence state of Mn exposed to the surface was a critical factor in O3 decomposition by Mn-Ti catalysts.

Synthesis and electrochemical properties of spherical and hollow-structured NiO aggregates created by combining the Kirkendall effect and Ostwald ripening.

The Kirkendall effect and Ostwald ripening were successfully combined to prepare uniquely structured NiO aggregates. In particular, a NiO-C composite powder was first prepared using a one-pot spray pyrolysis, which was followed by a two-step post-treatment process. This resulted in the formation of micron-sized spherical and hollow-structured NiO aggregates through a synergetic effect that occurred between nanoscale Kirkendall diffusion and Ostwald ripening. The discharge capacity of the spherical and hollow-structured NiO aggregates at the 500(th) cycle was 1118 mA h g(-1) and their capacity retention, which was measured from the second cycle, was nearly 100%. However, the discharge capacities of the solid NiO aggregates and hollow NiO shells were 631 and 150 mA h g(-1), respectively, at the 500(th) cycle and their capacity retentions, which were measured from the second cycle, were 63 and 14%, respectively. As such, the spherical and hollow-structured NiO aggregates, which were formed through the synergetic effect of nanoscale Kirkendall diffusion and Ostwald ripening, have high structural stability during cycling and have excellent lithium storage properties.

Electrochemical properties of yolk-shell structured ZnFe2O4 powders prepared by a simple spray drying process as anode material for lithium-ion battery.

ZnFe2O4 yolk-shell powders were prepared by applying a simple spray-drying process. Dextrin was used as a drying additive and carbon source material, and thus played a key role in the preparation of the powders. The combustion of precursor powders consisting of zinc and iron salts and dextrin obtained by a spray-drying process produced the yolk-shell-structured ZnFe2O4 powders even at a low post-treatment temperature of 350 °C. The ZnFe2O4 powders prepared from the spray solution without dextrin had a filled and pockmarked structure. The initial discharge capacities of the ZnFe2O4 yolk-shell and filled powders post-treated at 450 °C at a current density of 500 mA g(-1) were 1226 and 993 mA h g(-1), respectively, and the corresponding initial Coulombic efficiencies were 74 and 58%. The discharge capacities of the ZnFe2O4 powders with yolk-shell and filled structures post-treated at 450 °C after 200 cycles were 862 and 332 mA h g(-1), respectively. The ZnFe2O4 yolk-shell powders with high structural stability during cycling had superior electrochemical properties to those of the powders with filled structure.