Search

Magnetic semiconducting materials offer tremendous prospects for spin electronics but is challenging to achieve room-temperature ferromagnetism with unambiguous origin. Herein, a non-stoichiometry strategy is proposed to induce tunable magnetization in MoSe2−x nanoflowers via vacancy-controlled 2H–1T phase transition. The resultant MoSe2−x exhibits robust room-temperature ferromagnetism with significant positive correlation to the content of 1T phase and 2H–1T interfaces. Significant magnetic hysteresis and Curie transition above room temperature have been achieved, confirming the ferromagnetic feature of MoSe2−x. To examine the origin of ferromagnetism, formation energy and spin-polarized calculations have been conducted, indicating that the Se vacancy is beneficial for the formation of the 1T phase and interfacial spin polarization. Localized magnetic moments induced at the 2H–1T interfaces exhibit enhanced magnetism as compared to the net moments from the 1T orbital splitting, giving rise to strong coupling bound magnetic polarons. This work not only advances the understanding on the origin of magnetism in magnetic semiconductors, but also provides an effective route to generate ferromagnetism by defect and/or interface engineering that could be applied to multiferroics, spintronics, and valleytronics. [ABSTRACT FROM AUTHOR]

Food processing unavoidably introduces various risky ingredients that threaten food safety. N‐Nitrosamines (NAs) constitute a class of food contaminants, which are considered carcinogenic to humans. According to the compiled information, pretreatment methods based on solid‐phase extraction (SPE) were widely used before the determination of volatile NAs in foods. The innovation of adsorbents and hybridization of other methods have been confirmed as the future trends of SPE‐based pretreatment methods. Moreover, technologies based on liquid chromatography and gas chromatography were popularly applied for the detection of NAs. Recently, sensor‐based methods have garnered increasing attention due to their efficiency and flexibility. More portable sensor‐based technologies are recommended for on‐site monitoring of NAs in the future. The application of artificial intelligence can facilitate data processing during high‐throughput detection of NAs. Natural bioactive compounds have been confirmed to be effective in mitigating NAs in foods through antioxidation, scavenging precursors, and regulating microbial activities. Meanwhile, they exhibit strong protective activities against hepatic damage, pancreatic cancer, and other NA injuries. Further supplementation of data on the bioavailability of bioactives can be achieved through encapsulation and clinical trials. The utilization of bioinformatics tools rooted in various omics technologies is suggested for investigating novel mechanisms and finally broadening their applications in targeted therapies. [ABSTRACT FROM AUTHOR]

We investigate the crack-healing mechanism of 4H silicon carbide (4H-SiC) and reveal the effect of dopants on the crack-healing behavior of 4H-SiC. Vickers indentation tests and thermal annealing are utilized to generate cracks and heal cracks in 4H-SiC, respectively. High-temperature thermal annealing in the air atmosphere is found to be capable of effectively healing indentation-induced cracks and releasing indentation-induced stress in undoped 4H-SiC by the formation and viscous flow of glass phase SiO2. Nitrogen (N) doping is found to assist the atomic diffusion of 4H-SiC. The crack healing of N-doped 4H-SiC is realized by the synergy of host solid diffusion and the padding of glassy SiO2. In contrast, vanadium (V) doping hinders the viscous flow of SiO2 and results in the incomplete healing of cracks in V-doped 4H-SiC. Although the generation of cracks lowers the bending strength of 4H-SiC, the healing of cracks by the padding of glassy SiO2 is found to effectively recover the bending strength of indented 4H-SiC samples. Our work opens a pathway to design thermal processing technologies to heal the cracks and enhance the mechanical properties of 4H-SiC wafers. [ABSTRACT FROM AUTHOR]

Foodborne pathogenic infection has brought multifaceted issues to human life, leading to an urgent demand for advanced detection technologies. CRISPR/Cas-based biosensors have the potential to address various challenges that exist in conventional assays such as insensitivity, long turnaround time and complex pretreatments. In this perspective, we review the relevant strategies of CRISPR/Cas-assisted diagnostics on foodborne pathogens, focusing on biosensing platforms for foodborne pathogens based on fluorescence, colorimetric, (electro)chemiluminescence, electrochemical, and surface-enhanced Raman scattering detection. It summarizes their detection principles by the clarification of foodborne pathogenic bacteria, fungi, and viruses. Finally, we discuss the current challenges or technical barriers of these methods against broad application, and put forward alternative solutions to improve CRISPR/Cas potential for food safety. [ABSTRACT FROM AUTHOR]