Tuning the electronic properties and band offset of h-BN/diamond mixed-dimensional heterostructure by biaxial strain.

The h-BN/diamond mix-dimensional heterostructure has broad application prospects in the fields of optoelectronic devices and power electronic devices. In this paper, the electronic properties and band offsets of hexagonal boron nitride (h-BN)/(H, O, F, OH)-diamond (111) heterostructures were studied by first-principles calculations under biaxial strain. The results show that different terminals could significantly affect the interface binding energy and charge transfer of h-BN/diamond heterostructure. All heterostructures exhibited semiconductor properties. The h-BN/(H, F)-diamond systems were indirect bandgap, while h-BN/(O, OH)-diamond systems were direct bandgap. In addition, the four systems all formed type-II heterostructures, among which h-BN/H-diamond had the largest band offset, indicating that the system was more conducive to the separation of electrons and holes. Under biaxial strain the bandgap values of the h-BN/H-diamond system decreased, and the band type occurred direct-indirect transition. The bandgap of h-BN/(O, F, OH)-diamond system increased linearly in whole range, and the band type only transformed under large strain. On the other hand, biaxial strain could significantly change the band offset of h-BN/diamond heterostructure and promote the application of this heterostructure in different fields. Our work provides theoretical guidance for the regulation of the electrical properties of h-BN/diamond heterostructures by biaxial strain.

[3 + 2]-Annulations of N-alkyl-3-substituted indoles with quinone monoketals catalysed by Brønsted acids.

An organocatalytic dearomative [3 + 2]-annulation of N-alkyl-3-alkylindoles with quinone monoketals is developed. The reaction provides a mild and straightforward way to various benzofuro[2,3-b]indolines of potential biological and pharmaceutical interest in moderate to good yields. Moreover, when 3-phenylindole, a problematic substrate in previous relevant studies, was used as the substrate under the otherwise same reaction conditions, a novel 1,2-shift of the phenyl group occurred followed by aromatization to provide 2,3-diaryl indoles useful for cancer therapy studies in moderate yields.

Type I IFN receptor regulates neutrophil functions and innate immunity to Leishmania parasites.

Type I IFNs exert diverse effector and regulatory functions in host immunity to viral and nonviral infections; however, the role of endogenous type I IFNs in leishmaniasis is unclear. We found that type I IFNR-deficient (IFNAR-/-) mice developed attenuated lesions and reduced Ag-specific immune responses following infection with Leishmania amazonensis parasites. The marked reduction in tissue parasites, even at 3 d in IFNAR-/- mice, seemed to be indicative of an enhanced innate immunity. Further mechanistic analyses indicated distinct roles for neutrophils in parasite clearance; IFNAR-/- mice displayed a rapid and sustained infiltration of neutrophils, but a limited recruitment of CD11b+Ly-6C+ inflammatory monocytes, into inflamed tissues; interactions between IFNAR-/-, but not wild-type (WT) or STAT1-/-, neutrophils and macrophages greatly enhanced parasite killing in vitro; and infected IFNAR-/- neutrophils efficiently released granular enzymes and had elevated rates of cell apoptosis. Furthermore, although coinjection of parasites with WT neutrophils or adoptive transfer of WT neutrophils into IFNAR-/- recipients significantly enhanced infection, the coinjection of parasites with IFNAR-/- neutrophils greatly reduced parasite survival in WT recipients. Our findings reveal an important role for type I IFNs in regulating neutrophil/monocyte recruitment, neutrophil turnover, and Leishmania infection and provide new insight into innate immunity to protozoan parasites.