Scalable fabrication of NiCoMnO4 yolk-shell microspheres with gradient oxygen vacancies for high-performance aqueous zinc ion batteries.

Defect regulation, which enables better charge transfer and capacity retention in manganese-based cathode materials, is the key to the development of rechargeable aqueous zinc-ion batteries. Herein, yolk-shell structured NiCoMnO4-VO with gradient oxygen vacancies are synthesized by spray pyrolysis and ammonia etching. The generation of the yolk-shell structures are regulated by the diffusion rate of ions in the atomized droplets during the nucleation process instead of adding template agent. In addition, the etching effect of ammonia gradually dissolves nickel oxide in the material from the surface to the interior, creating abounding gradient oxygen vacancies and thereby achieving more active sites for zinc storage and faster charge transfer. Therefore, the material exhibits superior electrochemical performances with initial discharge capacities of 277.9 mA h g-1 at 0.2 A g-1, and the long-term capacities retention rate is 89.3% after 2800 cycles at 5 A g-1. Ex-situ XRD demonstrates NiCoMnO4-VO belongs to the embedding-extraction mechanism of H+ and Zn2+. In-situ optical microscopy reveals that the formation of zinc dendrites is suppressed to some extent.

Synergistic melamine intercalation and Zn(NO3)2 activation of N-doped porous carbon supported Fe/Fe3O4 for efficient electrocatalytic oxygen reduction.

Developing inexpensive, efficient and good stability transition metal-based oxygen reduction reaction (ORR) electrocatalysts is a research topic of great concern in the commercial application of fuel cells. Herein, with zinc nitrate as activator, iron nitrate as active component and melamine as intercalating agent and nitrogen source, an N-doped porous carbon supported Fe/Fe3O4 (Fe/Fe3O4@NC) catalyst is successfully synthesized by an impregnation-calcination method combined with freeze-drying technique. The positive onset potential (E onset), half-wave potential (E 1/2) and limiting current density (J L) of the optimal Fe/Fe3O4@NC catalyst are 1.012, 0.90 V vs. RHE and 5.87 mA cm-2, respectively. Furthermore, Fe/Fe3O4@NC catalyzes ORR mainly through a 4e- pathway, and the yield of H2O2 is less than 5%. It also manifests a robust stability after 5000 CV cycles of ADT testing, and the half-wave potential is only negatively shifted 17 mV. The structural characterization and experimental results further suggest that the outstanding ORR electrocatalytic performance of the Fe/Fe3O4@NC catalyst benefits from the synergetic effect of zinc nitrate activation and nitrogen doping, which can greatly improve the specific surface area, thus better dispersing more metal active sites. This work puts forward a simple and practicable way for preparing high-performance non-noble metal-based biomass ORR electrocatalysts.

Hexamethylenetetramine induced multidimensional defects in Co2P nanosheets for efficient alkaline hydrogen evolution.

Crystal engineering is an important way to improve the catalytic performance of transition-metal phosphides. In this work, we propose a strategy for constructing multi-dimensional defects induced by hexamethylenetetramine, which effectively introduces grain boundaries, N doping and P vacancies into Co2P nanosheets, and improves the activity and stability of the catalyst. Due to the synergistic effect of the multi-dimensional defects, the Co2P nanosheets exhibit excellent HER catalytic performance, especially at a large current density of 100 mA cm-2 with an overpotential of only 159 mV. Under 1 M KOH electrolyte and current density of 10 mA cm-2, the long-term test for 36 h shows that the catalyst maintains a very high stability.

Decreasing lncRNA HOTAIR expression inhibits human colorectal cancer stem cells.

Research on the relationship between aberrant long non-coding RNA (lncRNA) and cancer stem cell (CSC) biology in cancer patients has been recently gaining attention. The goal of this study was to investigate whether the decreasing lncRNA HOTAIR expression would inhibit human colorectal cancer (CRC) stem cells. CD133(+)CSCs were isolated from human CRC LoVo cell line by using a magnetic-activated cell sorting system, and were transfected with the expression vector-based small hairpin RNA targeting HOTAIR (shHOTAIR). The ability of cellular proliferation, migration, invasion, colony-forming, and the epithelial-mesenchymal transition (EMT)-associated molecule expression as well as the tumorigenicity of CD133(+)-shHOTAIR were evaluated by the MTT, wound-healing, cellular invasion, colony formation and Western blot assays, respectively. This study found that, when compared with control cells in vitro, CD133(+)-shHOTAIR exhibited the decreased HOTAIR expression, suppressed cellular proliferation, migration, invasion, colony-forming, and inhibited the Vimentin expression with increased E-cadherin expression. In particular, the down-regulation of the HOTAIR expression in CD133(+)CSCs markedly attenuated the tumor growth and lung metastasis in xenograft nude mice. Taken together, this study found that down-regulating the HOTAIR expression in CD133(+)CSCs could serve as a potential anti-cancer regimen to inhibit the invasiveness and metastasis of CRC CSCs.

Combining TGF-ß1 knockdown and miR200c administration to optimize antitumor efficacy of B16F10/GPI-IL-21 vaccine.

TGF-ß1 secreted abundantly by tumors cells as well as present in the local microenvironment promotes neoplasm invasion and metastasis by triggering the epithelial to mesenchymal transition (EMT). MiR200c has been shown to suppress EMT and to regulate the cellular epithelial and interstitial state conversion, whereas the tumor vaccines are intended to specifically initiate or amplify a host response against evolving tumor cells. Our study aimed at optimizing the antitumor effects of the B16F10/glycosylphosphatidylinositol-interleukin 21 (B16F10/GPI-IL-21) tumor vaccine on melanoma bearing mice by combining the TGF-ß1 knockdown and the administration of miR200c agomir. The mice were subcutaneously vaccinated with inactivated B16F10/GPI-IL-21 vaccine and challenged by B16F10 cells transfected with shTGF-ß1 (B16F10/shTGF-ß1 cells) or B16F10/shTGF-ß1 cells with the administration of miR200c agomir. The later combination showed that, when compared with the mice in the control group that received no vaccination, vaccinated mice significantly increased NK and CTL activities, enhanced levels of IFN-γ, and reduced expression of TGF-ß1, N-cadherin, Vimentin, Gli1/2, P-Smad2/3 and others involved in promoting expression of EMT-related molecules in tumor areas, and inhibited the melanoma metastasis in lungs and lymph nodes. Altogether, our findings demonstrate that this synergistic anti-cancer regimen effectively induces strong immune response and diminishes the melanoma progression.