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Abstract The structural and electronic properties of a monolayer and bilayer blue phosphorene/graphene-like GaN van der Waals heterostructures are studied using first-principle calculations. The results show that the monolayer-blue phosphorene/graphene-like GaN heterostructure is an indirect bandgap semiconductor with intrinsic type II band alignment. More importantly, the external electric field tunes the bandgap of monolayer-blue phosphorene/graphene-like GaN and bilayer-blue phosphorene/graphene-like GaN, and the relationship between bandgap and external electric field indicates a Stark effect. The semiconductor-to-metal transition is observed in the presence of a strong electric field.

IntroductionWe aimed to verify the application value of the Alberta Stroke Program Early CT Score (ASPECTS) based on multiple post-labeling delay (multi-PLD) arterial spin labeling (ASL) for outcome assessment in acute ischemic stroke (AIS) patients.MethodThe endpoint was modified Rankin scale score at 90 days (90-day mRS). Patients were divided into the good outcome (0–2) and poor outcome (3–6) groups. The independent samples t-test, Mann-Whitney U-test, and χ2-test were used to compare clinical and imaging parameters between groups. We used partial correlation analysis to evaluate the relationships between ASPECTS and outcomes. Multivariate logistic regression analysis was used to examine potential independent prognostic indicators. The receiver operating characteristic (ROC) curve analysis was used to evaluate the performance of the independent prognostic indicators in predicting outcomes.ResultsFifty-five AIS patients were included. The good outcome group had a lower baseline National Institutes of Health Stroke Scale (NIHSS; Z = −3.413, P < 0.001) and infarct core volume (ICV; Z = −3.114, P = 0.002) as well as higher cerebral blood flow (CBF)-ASPECTS (Z = −3.835, P < 0.001) and cerebral blood volume (CBV)-ASPECTS (Z = −4.099, P < 0.001). Higher CBF-ASPECTS (r = −0.459, P = 0.001), and CBV-ASPECTS (r = −0.502, P < 0.001) were associated with a lower 90-day mRS. The baseline NIHSS, CBF-ASPECTS, and CBV-ASPECTS were identified as independent prognostic indicators. The AUCs of the baseline NIHSS, CBF-ASPECTS, and CBV-ASPECTS were 83.3, 87.4, and 89.9%, respectively. Combining NIHSS with CBF-ASPECTS and CBV-ASPECTS, the AUC significantly improved to 96.3%. The combined three factors showed a significant difference compared to the baseline NIHSS (Z = 2.039, P = 0.041) and CBF-ASPECTS (Z = 2.099, P = 0.036), but no difference with CBV-ASPECTS (Z = 1.176, P = 0.239).ConclusionsThe ASPECTS based on multi-PLD ASL is a valuable tool for identifying independent prognostic indicators and assessing clinical outcomes in AIS patients. The baseline NIHSS, combined with CBF-ASPECTS and CBV-ASPECTS, enhances the predictive efficacy of clinical outcomes in AIS patients. The CBV-ASPECTS alone can offer comparable predictive efficacy to the combination.

In this study, the Co(3-x)MnxO4@TiO2 core-shell catalysts prepared by sol-gel and external kinetic coating method were investigated for DeNOx by response surface methodology (RSM) using 3-factor with 5-level experiments. Compared with CoMn2O4 sample, the CoMn2O4@TiO2 catalyst was optimized to obtain almost 100% NOx conversion at 125°C to 225°C that also maintained above 80% SCR activity with 100 ppm SO2 and 10 vol.% H2O in the testing time within 24 h. The XRD and Raman show a clear distinction of that CoMn2O4 spinel phase was well-dispersed on anatase TiO2 over CoMn2O4@TiO2 catalyst, which exhibited a core-shell structure with obvious distribution boundary of CoMn2O4 core coated by TiO2 shell confirmed by TEM images. This intact catalyst presented complete TiO2 coating structure due to the detected bonds Mn-O, Co-O and particular Ti-O via FT-IR analysis. NH3-TPD and H2-TPR profiles indicated that the CoMn2O4@TiO2 catalyst owned more acid sites, stronger acidity and enhanced redox capacities benefiting from its core-shell structure after TiO2 coating. According to XPS analysis, higher content of (Mn3++Mn4+)/(Mn2++Mn3++Mn4+) (77.7%), Co3+/ (Co2+ + Co3+) (53.5%) and surface oxygen (26.1%) were in favour of valence electron interaction (Mn4++Co2+↔Mn3++ Co3+, Mn3++Ti4+↔Mn4++ Ti3+). The NH3-SCR reaction pathways over CoMn2O4 and CoMn2O4@TiO2 catalysts were compared and proposed through DRIFTS experiments, which mainly follows the typical Eley-Rideal (E-R) mechanism, while the Langmuir-Hinshelwood (L-H) mechanism is weak at 225 °C. This study opens up a new avenue for designing efficient and environment-friendly NH3-SCR catalysts and looks promising for practical application.

Micro (mi)RNAs are short non-coding RNA molecules, which post-transcriptionally regulate gene expression and exert key roles in cell growth, differentiation and apoptosis. In the present study, the mechanism and the function of miR-1915-3p in the apoptotic regulation of lung cancer cell lines (NCI-H441 and NCI-H1650) were investigated. The expression analysis confirmed that the expression of miR-1915-3p was markedly decreased in the apoptotic cells. The overexpression of miR-1915-3p in the lung cancer cells prevented apoptosis induced by etoposide. Developmentally regulated GTP-binding protein 2 (DRG2) and pre-B cell leukemia homeobox 2 (PBX2) were identified as downstream targets of miR-1915-3p, which was shown to bind directly to the 3'-untranslated region of DRG2 and PBX2, subsequently lowering their mRNA and protein expression levels. Co-expression of miR-1915-3p and DRG2/PBX2 in the NCI-H441 and NCI-H1650 cells partly circumvented the effect of miR-1915-3p on apoptosis. The results in the present study revealed that miR-1915-3p functions as a silencer of apoptosis, which regulates lung cancer apoptosis via targeting DRG2/PBX2, and consequently this miRNA may be a putative therapeutic target in lung cancer. [ABSTRACT FROM AUTHOR]

To analyze the distortion problem of two-dimensional micro-electromechanical system (MEMS) micromirror in-plane scanning, this paper makes a full theoretical analysis of the distortion causes from many aspects. Firstly, the mathematical relations among the deflection angle, laser incidence angle, and plane scanning distance of the micromirror are constructed, and the types of projection distortion of the micromirror scanning are discussed. Then the simulation results of reflection angle distribution and point cloud distribution are verified by MATLAB software under different working conditions. Finally, a two-dimensional MEMS micromirror scanning projection system is built. The predetermined waveform can be scanned and projected successfully. The distortion theory is proved to be correct by analyzing the distortion of the projection images, which lays a foundation for practical engineering application.

The digital elevation model (DEM) generates a digital simulation of ground terrain in a certain range with the usage of 3D point cloud data. It is an important source of spatial modeling information. Due to various reasons, however, the generated DEM has data holes. Based on the algorithm of deep learning, this paper aims to train a deep generation model (DGM) to complete the DEM void filling task. A certain amount of DEM data and a randomly generated mask are taken as network inputs, along which the reconstruction loss and generative adversarial network (GAN) loss are used to assist network training, so as to perceive the overall known elevation information, in combination with the contextual attention layer, and generate data with reliability to fill the void areas. The experimental results have managed to show that this method has good feature expression and reconstruction accuracy in DEM void filling, which has been proven to be better than that illustrated by the traditional interpolation method.

Collagen plays an important role in the formation of extracellular matrix (ECM) and development/migration of cells and tissues. Here we report the preparation of collagen and collagen hydrogel from the skin of tilapia and an evaluation of their potential as a wound dressing for the treatment of refractory wounds. The acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were extracted and characterized using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), differential scanning calorimetry (DSC), circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR) analysis. Both ASC and PSC belong to type I collagen and have a complete triple helix structure, but PSC shows lower molecular weight and thermal stability, and has the inherent low antigenicity. Therefore, PSC was selected to prepare biomedical hydrogels using its self-aggregating properties. Rheological characterization showed that the mechanical strength of the hydrogels increased as the PSC content increased. Scanning electron microscope (SEM) analysis indicated that hydrogels could form a regular network structure at a suitable PSC content. Cytotoxicity experiments confirmed that hydrogels with different PSC content showed no significant toxicity to fibroblasts. Skin repair experiments and pathological analysis showed that the collagen hydrogels wound dressing could significantly accelerate the healing of deep second-degree burn wounds and the generation of new skin appendages, which can be used for treatment of various refractory wounds.

Two-dimensional materials have recently been the focus of extensive research. Graphene-based vertical van der Waals heterostructures are expected to design and fabricate novel electronic and optoelectronic devices. Monolayer gallium telluride is a graphene-like nanosheet synthesized in experiment. Here, the electronic properties of GaTe/graphene heterostructures are investigated under the interlayer coupling and the applied perpendicular electric field. The results show that the electronic properties of GaTe and graphene are preserved, and the energy bandgap of graphene is opened to 13.5 meV in the GaTe/graphene heterostructure. It is found that the n-type Schottky contact is formed in the GaTe/graphene heterostructure, which can be tuned by the interlayer coupling, and the applied electric field. Moreover, a transformation from n-type to p-type Schottky contact is observed when the interlayer distance is smaller than 3.15 Å or the applied electric field is larger than 0.05 V Å−1. These properties are fundamental to the design of new Schottky nanodevices based on the GaTe/graphene heterostructure. [ABSTRACT FROM AUTHOR]