Martens Bondesen (loanhelen23)

Using first-principles calculations, we predict that the two-dimensional (2D) monolayers of NbP with the buckled honeycomb-like and puckered tetragonal structure can be obtained from the (110) and (001) orientations, respectively, of its bulk crystal structure. The electronic properties of these monolayers are spectacularly different as tetragonal lattice is metallic whereas the honeycomb-like lattice (h-NbP) is a semiconductor and exhibits intrinsic ferroelectricity originating from a raresd2-sp2hybridization. The shift current bulk photovoltaic effect (BPVE) is systematically investigated in the h-NbP monolayer (1.21 Å thickness) using the Wannier interpolation method. Strong absorption of visible light at ∼2 eV and a large 3D shift current of ∼180μA V-2is obtained which is attributed to the partial delocalization of Bloch states due tosd2-sp2hybridization. We compare the shift current response of h-NbP monolayer with that of some previously reported bulk ferroelectrics and 2D monolayers, suggesting that h-NbP monolayer can yield a large shift current at an ultimate thickness and is a promising 2D material for the BPVE application under the visible light. Strain effect is also investigated, revealing that the h-NbP monolayer is dynamically stable up to a strain limit of ±3%, and the shift current increases by ∼9% at a compressive strain of -3% as the Bloch states are more delocalized due to the strengthening ofsd2-sp2hybridization. The results presented in this study can pave the paths to fabricate the 2D monolayered structures of NbP, and realize the BPVE based next-generation solar cells of h-NbP monolayer.Magnetic skyrmions are potential building blocks for future information storage and computing devices. Here, we computationally study the skyrmion dynamics in a cross structure made of two ferromagnetic nanotracks. We show that by controlling the skyrmion motion in the cross structure using spin currents, it is possible to realize the transcription of skyrmion at the intersection of the cross structure at certain conditions. Based on the transcription of skyrmion, we computationally demonstrate the AND, OR and NOT logical gates using the cross structures with modified geometries and appropriate magnetic parameters. Our results may provide guidelines to design future three-dimensional spintronics devices based on magnetic skyrmions.Emerging evidence proves that exosomes contain specific microRNAs(miRNAs) contribute to osteogenic differentiation of bone marrow stem cells (BMSCs). However, the role and mechanism of bone marrow stem cells (BMSCs)-derived exosomes overexpressing miR-424-5p in osteoblasts remains unclear. Firstly, the BMSCs-derived exosomes were isolated, and identified by Western blot with the exosome surface markers CD9, CD81 and CD63. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect the level of miR-424-5p in exosomes, and western blot was implemented to verify the WIF1/Wnt/β-catenin expression. The binding association between miR-424-5p and WIF1 was determined by the dual-luciferase reporter gene assay. Functional enhancement experiments were adopted to determine the role of exosome-carried miR-424-5p and WIF1/Wnt/β-catenin in osteogenic differentiation. ALP staining was adopted, and levels of RUNX2, OCN, and OPN were monitored using qRT-PCR to determine osteogenic differentiation. As a result, In vivo experiments showed that RUNX2, OCN and OPN levels decreased and the ALP activity was dampened after miR-424-5p overexpression in exosomes. Besides, exosomes overexpressing miR-424-5p attenuated osteogenic development via WIF1/Wnt/β-catenin. Our findings may bring evidence for miR-424-5p as a new biomarker for the treatment of osteoporosis.Metastatic cancer especially bone metastasis (BM) is the lethal end-stage of castration-resistant prostate cancer (CRPC). To understand the possible molecular mechanisms underlying the d