Light Confinement Effect Induced Highly Sensitive, Self-Driven Near-Infrared Photodetector and Image Sensor Based on Multilayer PdSe2 /Pyramid Si Heterojunction.

In this study, a highly sensitive and self-driven near-infrared (NIR) light photodetector based on PdSe2 /pyramid Si heterojunction arrays, which are fabricated through simple selenization of predeposited Pd nanofilm on black Si, is demonstrated. The as-fabricated hybrid device exhibits excellent photoresponse performance in terms of a large on/off ratio of 1.6 × 105 , a responsivity of 456 mA W-1 , and a high specific detectivity of up to 9.97 × 1013 Jones under 980 nm illumination at zero bias. Such a relatively high sensitivity can be ascribed to the light trapping effect of the pyramid microstructure, which is confirmed by numerical modeling based on finite-difference time domain. On the other hand, thanks to the broad optical absorption properties of PdSe2 , the as-fabricated device also exhibits obvious sensitivity to other NIR illuminations with wavelengths of 1300, 1550, and 1650 nm, which is beyond the photoresponse range of Si-based devices. It is also found that the PdSe2 /pyramid Si heterojunction device can also function as an NIR light sensor, which can readily record both "tree" and "house" images produced by 980 and 1300 nm illumination, respectively.

Thermodynamic Simulation Calculations of Phase Transformations in Low-Aluminum Zn-Al-Mg Coatings.

This study delves into the formation, transformation, and impact on coating performance of MgZn2 and Mg2Zn11 phases in low-aluminum Zn-Al-Mg alloy coatings, combining thermodynamic simulation calculations with experimental verification methods. A thermodynamic database for the Zn-Al-Mg ternary system was established using the CALPHAD method, and this alloy's non-equilibrium solidification process was simulated using the Scheil model to predict phase compositions under varying cooling rates and coating thicknesses. The simulation results suggest that the Mg2Zn11 phase might predominate in coatings under simulated production-line conditions. However, experimental results characterized using XRD phase analysis show that the MgZn2 phase is the main phase existing in actual coatings, highlighting the complexity of the non-equilibrium solidification process and the decisive effect of experimental conditions on the final phase composition. Further experiments confirmed that cooling rate and coating thickness significantly influence phase composition, with faster cooling and thinner coatings favoring the formation of the metastable phase MgZn2.

Next-Generation Green Hydrogen: Progress and Perspective from Electricity, Catalyst to Electrolyte in Electrocatalytic Water Splitting.

Green hydrogen from electrolysis of water has attracted widespread attention as a renewable power source. Among several hydrogen production methods, it has become the most promising technology. However, there is no large-scale renewable hydrogen production system currently that can compete with conventional fossil fuel hydrogen production. Renewable energy electrocatalytic water splitting is an ideal production technology with environmental cleanliness protection and good hydrogen purity, which meet the requirements of future development. This review summarizes and introduces the current status of hydrogen production by water splitting from three aspects: electricity, catalyst and electrolyte. In particular, the present situation and the latest progress of the key sources of power, catalytic materials and electrolyzers for electrocatalytic water splitting are introduced. Finally, the problems of hydrogen generation from electrolytic water splitting and directions of next-generation green hydrogen in the future are discussed and outlooked. It is expected that this review will have an important impact on the field of hydrogen production from water.

Altitude, not potential larval habitat availability, explains pronounced variation in Plasmodium falciparum infection prevalence in the western Kenya highlands.

Progress in malaria control has stalled over the recent years. Knowledge on main drivers of transmission explaining small-scale variation in prevalence can inform targeted control measures. We collected finger-prick blood samples from 3061 individuals irrespective of clinical symptoms in 20 clusters in Busia in western Kenya and screened for Plasmodium falciparum parasites using qPCR and microscopy. Clusters spanned an altitude range of 207 meters (1077-1284 m). We mapped potential mosquito larval habitats and determined their number within 250 m of a household and distances to households using ArcMap. Across all clusters, P. falciparum parasites were detected in 49.8% (1524/3061) of individuals by qPCR and 19.5% (596/3061) by microscopy. Across the clusters, prevalence ranged from 26% to 70% by qPCR. Three to 34 larval habitats per cluster and 0-17 habitats within a 250m radius around households were observed. Using a generalized linear mixed effect model (GLMM), a 5% decrease in the odds of getting infected per each 10m increase in altitude was observed, while the number of larval habitats and their proximity to households were not statistically significant predictors for prevalence. Kitchen located indoors, open eaves, a lower level of education of the household head, older age, and being male were significantly associated with higher prevalence. Pronounced variation in prevalence at small scales was observed and needs to be taken into account for malaria surveillance and control. Potential larval habitat frequency had no direct impact on prevalence.

Resveratrol reduces p38 mitogen-activated protein kinase phosphorylation by activating Sirtuin 1 to alleviate cognitive dysfunction after traumatic brain injury in mice.

Traumatic brain injury (TBI) is characterized by neuronal loss and subsequent brain damage and can be accompanied by transient or permanent neurological dysfunction. The recovery of cognitive function after TBI is a challenge. This study aimed at investigating whether treatment with resveratrol (RSV) could prevent cognitive dysfunction after TBI in mice. TBI mouse model using weight drop-impact method. Male mice aged from 7 to 9 weeks were randomly divided into four groups: TBI group, TBI + vehicle group, TBI + RSV group, and sham-operated control group. The animals from the TBI + vehicle group and TBI + RSV group were intraperitoneally injected at 3 and 24 h post-TBI with placebo and RSV (3%, 5 ml/kg), respectively. Two days after TBI, the hippocampus of mice was extracted, and western blot analysis was performed for Sirtuin 1 (SIRT1), synaptophysin (SYP), p38 mitogen-activated protein kinase (MAPK), and P-p38 MAPK. Moreover, behavioral functions of TBI mice were evaluated by Y maze to determine RSV efficacy in preventing cognitive impairment in TBI. RSV increased the expression of SIRT1 protein, which in turn activated the phosphorylation of p38 MAPK. Taken together, our findings suggest that RSV exerts a strong beneficial effect on improving neurological function induced by TBI.

Resveratrol activates the SIRT1/PGC-1 pathway in mice to improve synaptic-related cognitive impairment after TBI.

Traumatic brain injury (TBI) is the most common form of craniocerebral injury. Post-TBI neurological impairment is often accompanied by cognitive dysfunction. The potential molecular mechanisms of post-TBI cognitive impairment are not well characterized. Resveratrol, a natural polyphenolic agent, has been shown to improve cognitive function in neurological disorders and aging models through its anti-inflammatory activity. However, whether it can affect synapses to improve cognitive function and the potential mechanisms are not clear. Synapse plays an important role in cognitive function, and synaptophysin(SYN) is one of the important factors involved in synapse formation. Sirtuin 1 (SIRT1) has a neuroprotective effect via its effect on various biological processes, such as inflammation, metabolism, apoptosis, and autophagy. The results of this research suggest that resveratrol increases synaptophysin by activating the SIRT1/PGC-1 pathway and improves post-TBI cognitive function. Use of SIRT1 inhibitor (EX-527) and agonist (SRT1720) in the mice experiments verified the effect and mechanism of action of resveratrol in improving cognitive function. Our study identifies potential therapeutic targets for post-TBI cognitive dysfunction.

Upregulation of miR-340 Inhibits Tumor Growth and Mesenchymal Transition via Targeting c-MET in Glioblastoma.

BACKGROUND: Epithelial-mesenchymal Transition (EMT) is involved in various cancers including glioblastoma. Our previous study has shown that miR-340 negatively correlated with EMT process in glioblastoma. PURPOSE: In the present study, we aim to explore the underlying molecular mechanisms of miR-340 in EMT process of glioblastomas. MATERIALS AND METHODS: Using RT-qPCR assay, we analyzed the expression of miR-340 in glioma cell lines and normal human glia (NHA) cell line. Using CCK8, Colony formation assays, transwell and Western blot assays, we investigated tumor growth and EMT process. Using luciferase reporter assay, we confirmed a target of miR-340. RESULTS: Our results showed that miR-340 was down-regulated in glioma cell lines (U87, U251 and LN229) compared to NHA cells. MiR-340 overexpression remarkably inhibited cell proliferation and invasion as well as up-regulated E-cadherin expression and down-regulated N-cadherin, Vimentin, ZEB1, Slug and Snail expressions in U251 and LN229 cells. Further studies have confirmed c-MET as a target gene of miR-340. The EMT-inhibitory effect of miR-340 was lost after c-MET expression was restored. We also identified the antitumorigenic activity of miR-340 in vivo. CONCLUSION: These results demonstrated that miR-340 functioned as a tumor suppressor via targeting EMT process and could be a potential therapeutic candidate for treating glioblastomas.

Sensitive Deep Ultraviolet Photodetector and Image Sensor Composed of Inorganic Lead-Free Cs3Cu2I5 Perovskite with Wide Bandgap.

In this work, a sensitive deep ultraviolet (DUV) light photodetector based on inorganic and lead-free Cs3Cu2I5 crystalline film derived by a solution method was reported. Optoelectronic characterization revealed that the perovskite device exhibited nearly no sensitivity to visible illumination with wavelength of 405 nm but exhibited pronounced sensitivity to both DUV and UV light illumination with response speeds of 26.2/49.9 ms for rise/fall time. The Ilight/Idark ratio could reach 127. What is more, the responsivity and specific detectivity were calculated to be 64.9 mA W-1 and 6.9 × 1011 Jones, respectively. In addition, the device could keep its photoresponsivity after storage in air environment for a month. It is also found that the capability of Cs3Cu2I5 crystalline film device can readily record still DUV image with acceptable resolution. The above results confirm that the DUV photodetector may hold great potential for future DUV optoelectronic device and systems.

Mesoporous anodic α-Fe2O3 interferometer for organic vapor sensing application.

In this work, we reported the utilization of mesoporous α-Fe2O3 films as optical sensors for detecting organic vapors. The mesoporous α-Fe2O3 thin films, which exhibited obvious Fabry-Perot interference fringes in the reflectance spectrum, were successfully fabricated through electrochemical anodization of Fe foils. Through monitoring the optical thickness of the interference fringes, three typical organic species with different vapor pressures and polarities (hexane, acetone and isopropanol) were applied as probes to evaluate the sensitivity of the α-Fe2O3 based interferometric sensor. The experiment results showed that the as-synthesized mesoporous α-Fe2O3 interferometer displayed high reversibility and stability for the three organic vapors, and were especially sensitive to isopropanol, with a detection limit of about 65 ppmv. Moreover, the photocatalytic properties of α-Fe2O3 under visible light are beneficial for degradation of dodecane vapor residues in the nano-pores and refreshment of the sensor, demonstrating good self-cleaning properties of the α-Fe2O3-based interferometric sensor.