Hierarchical TiO2 spheres assisted with graphene for a high performance lithium–sulfur battery

In this study, we report hierarchical TiO2 sphere–sulfur frameworks assisted with graphene as a cathode material for high performance lithium–sulfur batteries. With this strategy, the volume expansion and aggregation of sulfur nanoparticles can be effectively mitigated, thus enabling high sulfur utilization and improving the specific capacity and cycling stability of the electrode. Modification of the TiO2–S nanocomposites with graphene can trap the polysulfides via chemisorption and increase the electronic connection among various components. The graphene-assisted TiO2–S composite electrodes exhibit high specific capacity of 660 mA h g−1 at 5C with a capacity loss of only 0.04% per cycle in the prolonged charge–discharge processes at 1C

Manufacture and Quality Control of Human Umbilical Cord-Derived Mesenchymal Stem Cell Sheets for Clinical Use

Human umbilical cord-derived mesenchymal stem cell (UC−MSC) sheets have attracted much attention in cell therapy. However, the culture media and coating matrix used for the preparation of UC−MSC sheets have not been safe enough to comply with current clinical drug standards. Moreover, the UC−MSC sheet preservation systems developed before did not comply with Good Manufacturing Practice (GMP) regulations. In this study, the culture medium and coating matrix were developed for UC−MSC sheet production to comply with clinical drug standards. Additionally, the GMP-compliant preservation solution and method for the UC−MSC sheet were developed. Then, quality standards of the UC−MSC sheet were formulated according to national and international regulations for drugs. Finally, the production process of UC−MSC sheets on a large scale was standardized, and three batches of trial production were conducted and tested to meet the established quality standards. This research provides the possibility for clinical trials of UC−MSC sheet products in the development stage of new drugs and lays the foundation for industrial large-scale production after the new drug is launched

Engineering NiS/Ni2P Heterostructures for Efficient Electrocatalytic Water Splitting

Developing high-active and low-cost bifunctional materials for catalyzing hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) holds pivotal role in water splitting. Therefore, we present a new strategy to form NiS/Ni2P heterostructures. The as-obtained NiS/Ni2P/CC requires overpotentials of 111 mV for the HER and 265 mV for the OER to reach a current density of 20 mA cm-2, outperforming their counterparts such as NiS and Ni2P under the same conditions. Additionally, the NiS/Ni2P/CC electrode requires a 1.67 V cell voltage to deliver 10 mA cm-2 in two-electrode electrolysis system, which is comparable to the cell using the benchmark Pt/C||RuO2 electrode. Detailed characterizations reveal that strong electronic interactions between NiS and Ni2P, abundant active sites, and smaller charge transfer resistance contribute to the improved HER and OER activity

The Behavior of Moist Potential Vorticity in the Interactions of Binary Typhoons Lekima and Krosa (2019) in with Different High-Resolution Simulations

The binary typhoon systems of Lekima and Krosa (2019) have been simulated using the Weather Research and Forecast (WRF) model with 27 km, 9 km, and 3 km resolutions and their behaviors of moist potential vorticity (MPV) in these simulations have been analyzed. All the simulations clearly show that the main sources of instability energy include two parts of MPV—the convective energy from the environmental field (MPV1) and the internal transferring energy between the binary typhoons (MPV2). While typhoons absorb the convective energy from the upper ocean through vortex effects on their periphery as the main external MPV sources, there is an MPV conveying belt at the middle-low layer of the atmosphere in the binary typhoon system, transferring energy between binary typhoons and causing atmospheric baroclinicity changes. While all three-resolution simulations show the fundamental features of MPV and its transferring in the binary typhoon system, the 3 km resolution cloud-resolving simulation yield more detailed and accurate MPV structures inside the individual typhoon, which may have non-negligible feedbacks on the background. Based on the comprehensive characteristics of MPV in binary typhoon interactions, further understanding of the interactions of internal detailed structures inside typhoons and their feedbacks on the background may provide a theoretical basis for improving the forecast of typhoon intensity and track