No abstract

Orthorhombic LuFeO 3 is an important member of rare-earth orthoferrites ReFeO 3 whose appealing physical features have drawn much attention due to its various potential applications. In this work, pure phase LuFeO 3 ceramics have been prepared by a mechanochemical activation-assisted solid-state reaction (MAS) method and conventional solid-state reaction (CSS) method for comparison. X-ray Diffraction (XRD) studies demonstrated that the mechanochemical activation process can lower the starting reaction temperature and substantially shorten the time to complete the reaction of LuFeO 3 ceramics. Besides, more homogeneous and highly denser LuFeO 3 ceramics can be obtained using the MAS method revealed by the density measurement and Scanning Electron Microscopy. It was revealed by XRD and Raman measurements that there is a little increase in lattice constant in the MAS sample compared to the CSS sample. The complex impedance spectra illustrated that the MAS sample has a much higher resistance than the CSS sample, which is caused by the higher density and fewer oxygen vacancies verified by X-Ray Photoelectron Spectroscopy.We believe that this study will contribute to solving the common leakage problems in ReFeO 3 ceramics and the investigation of its multiferroic properties. K E Y W O R D Sleakage, mechanochemical activation, multiferroics, oxygen vacancies, rare-earth orthoferrites 3020 | WANG et Al.

Native starch (NS) from different botanical origins (native rice/tapioca/oat starch, NRS/NTS/NOS) were hydrophobically modified by octenyl succinic anhydride (OSA), and the octenyl succinic (OS) groups were successfully introduced in the starch molecules which obtained OS-starch (OSRS, OSTS and OSOS) with different levels of modification (0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%) and degree of substitution (DS). The structural properties of the OS-starch, such as granule size, crystal, wettability and morphology were studied, and the OS-starch was used as particulate stabilizers to produce oil-in-water (O/W) Pickering emulsions. The emulsion index, droplet size distribution and microstructures of Pickering emulsions produced by different OS-starches were compared. OSA modification had almost no effect on the morphology or crystal structure types of three kinds of NS and OS-starch but markedly increased the contact angle and particle size distribution of OSRS, OSTS and OSOS. Esterification reaction of OSA and starch mainly occurred in amorphous regions of starch, and the OSA significantly improved the emulsifying capacity of OSRS, OSTS and OSOS granules and thus stabilized emulsions formed at higher levels (2.5% and 3.0%) of modification of OS-Starch exhibited better stability; the ability of OS-starch to stabilize Pickering emulsion was 3.0% OSRS > 3.0% OSOS > 3.0% OSTS, respectively. Observation and structural properties analysis of OS-starch granules and Pickering emulsion droplets showed that the number and thickness of the starch granules on the oil-water interface of the emulsion droplets increased with improvement of the OSA modification level, and an aggregation state was formed between the OS-starch granules, which was also enhanced with the OSA modification levels. These were all necessary for the Pickering emulsion stabilized by starch granules to remain in a steady state.

In order to improve the applicability in some extreme environments, a large number of research efforts have been conducted using carrier materials loaded with phase-change materials (PCMs). Wheat bran (WB), a kind of agroforestry waste and inexpensive biomass, is often ignored and discarded and further becomes a serious environmental threat. In this work, an effective high-value utility of WB in the field of composite PCMs was designed. First, briefness and efficient alkali-treated methods were adopted to control the degree of starch gelatinization of WB and the components within WB were entangled to form a threedimensional network, and then the alkali−wheat bran aerogels (AWBs) were obtained via freeze-drying method. The AWBs were utilized as biomass carriers to incorporate polyethylene glycol (PEG), and the composite PCMs (AWBs-PEG) were fabricated. The morphological structure and the properties of antileakage, thermal storage, thermal stability, and temperature regulation of the fabricated composite PCMs were studied. The results indicated that AWBs exhibited excellent performances including good antileakage and high PEG adsorption rate (up to 86.2%). The melting and crystallization enthalpy values of AWBs-PEG could reach 153.5 J/g and 134.3 J/g, respectively. It could also be found that AWBs-PEG possessed a superior thermal cycle stability, thermal reliability, and temperature regulation ability. The integration of AWBs-PEG with temperature sensitive ink demonstrated an exciting color-change buffering property. It would provide an innovative direction for solar thermal energy storage, thermal infrared stealth, advanced smart textiles, and other research fields.

To develop inhibitors targeting DNA damage repair pathways is important to improve the effectiveness of chemo- and radiotherapy for cancer patients. Rad51 mediates homologous recombination (HR) repair of DNA damages. It is widely overexpressed in human cancers and overwhelms chemo- and radiotherapy-generated DNA damages through enhancing HR repair signaling, preventing damage-caused cancer cell death. Therefore, to identify inhibitors of Rad51 is important to achieve effective treatment of cancers. Transcription factor Nanog is a core regulator of embryonic stem (ES) cells for its indispensable role in stemness maintenance. In this study, we identified Nanog as a novel inhibitor of Rad51. It interacts with Rad51 and inhibits Rad51-mediated HR repair of DNA damage through its C/CD2 domain. Moreover, Rad51 inhibition can be achieved by nanoscale material- or cell-penetrating peptide (CPP)-mediated direct delivery of Nanog-C/CD2 peptides into somatic cancer cells. Furthermore, we revealed that Nanog suppresses the binding of Rad51 to single-stranded DNAs to stall the HR repair signaling. This study provides explanation for the high γH2AX level in unperturbed ES cells and early embryos, and suggests Nanog-C/CD2 as a promising drug candidate applied to Rad51-related basic research and therapeutic application studies.