Binding properties of chemosensory protein 4 in Riptortus pedestris to aggregation pheromones.

In insects, chemosensory proteins (CSPs) play an important role in the perception of the external environment and have been widely used for protein-binding characterization. Riptortus pedestris has received increased attention as a potential cause of soybean staygreen syndrome in recent years. In this study, we found that RpedCSP4 expression in the antennae of adult R. pedestris increased with age, with no significant difference in expression level observed between males and females, as determined through quantitative real-time polymerase chain reaction (qRT-PCR). Subsequently, we investigated the ability of RpedCSP4 to bind various ligands (five aggregated pheromone components and 13 soybean volatiles) using a prokaryotic expression system and fluorescence competitive binding assays. We found that RpedCSP4 binds to three aggregated pheromone components of R. pedestris, namely, ((E)-2-hexenyl (Z)-3-hexenoate (E2Z3), (E)-2-hexenyl (E)-2-hexenoate (E2E2), and (E)-2-hexenyl hexenoate (E2HH)), and that its binding capacities are most stable under acidic condition. Finally, the structure and protein-ligand interactions of RpedCSP4 were further analyzed via homology modeling, molecular docking, and targeted mutagenesis experiments. The L29A mutant exhibited a loss of binding ability to these three aggregated pheromone components. Our results show that the olfactory function of RpedCSP4 provides new insights into the binding mechanism of RpedCSPs to aggregation pheromones and contributes to discover new target candidates that will provide a theoretical basis for future population control of R. pedestris.

Establishing a prognostic model based on immune-related genes and identification of BIRC5 as a potential biomarker for lung adenocarcinoma patients.

BACKGROUND: Lung adenocarcinoma (LUAD) is an extraordinarily malignant tumor, with rapidly increasing morbidity and poor prognosis. Immunotherapy has emerged as a hopeful therapeutic modality for lung adenocarcinoma. Furthermore, a prognostic model (based on immune genes) can fulfill the purpose of early diagnosis and accurate prognostic prediction. METHODS: Immune-related mRNAs (IRmRNAs) were utilized to construct a prognostic model that sorted patients into high- and low-risk groups. Then, the prediction efficacy of our model was evaluated using a nomogram. The differences in overall survival (OS), the tumor mutation landscape, and the tumor microenvironment were further explored between different risk groups. In addition, the immune genes comprising the prognostic model were subjected to single-cell RNA sequencing to investigate the expression of these immune genes in different cells. Finally, the functions of BIRC5 were validated through in vitro experiments. RESULTS: Patients in different risk groups exhibited sharply significant variations in OS, pathway activity, immune cell infiltration, mutation patterns, and immune response. Single-cell RNA sequencing revealed that the expression level of BIRC5 was significantly high in T cells. Cell experiments further revealed that BIRC5 knockdown markedly reduced LUAD cell proliferation. CONCLUSION: This model can function as an instrumental variable in the prognostic, molecular, and therapeutic prediction of LUAD, shedding new light on the optimal clinical practice guidelines for LUAD patients.

Binding properties of chemosensory protein 12 in Riptortus pedestris to aggregation pheromone (E)-2-hexenyl (Z)-3-hexenoate.

Riptortus pedestris (bean bug), a common soybean pest, has a highly developed olfactory system to find hosts for feeding and oviposition. Chemosensory proteins (CSPs) have been identified in many insect species; however, their functions in R. pedestris remain unknown. In this study, quantitative real time-polymerase chain reaction (qRT-PCR) revealed that the expression of RpedCSP12 in the adult antennae of R. pedestris increased with age. Moreover, a significant difference in the expression levels of RpedCSP12 was observed between male and female antennae at one and three days of age. We also investigated the binding ability of RpedCSP12 to different ligands using a prokaryotic expression system and fluorescence competitive binding assays. We found that RpedCSP12 only bound to one aggregation pheromone, (E)-2-hexenyl (Z)-3-hexenoate, and its binding decreased with increasing pH. Furthermore, homology modelling, molecular docking, and site-directed mutagenesis revealed that the Y27A, L74A, and L85A mutants lost their binding ability to (E)-2-hexenyl (Z)-3-hexenoate. Our findings highlight the olfactory roles of RpedCSP12, providing insights into the mechanism by which RpedCSPs bind to aggregation pheromones. Therefore, our study can be used as a theoretical basis for the population control of R. pedestris in the future.

Atomic-scale insights into the interfacial charge transfer in a NiO/CeO2 heterostructure for electrocatalytic hydrogen evolution.

To understand the underlying mechanism of the interfacial charge transfer and local chemical state variation in the nonprecious-based hydrogen evolution reaction (HER) electrocatalysts, a model system of the NiO/CeO2 heterostructure was chosen for investigation using a combination of the advanced electron microscopic characterization and first-principles calculations. The results directly proved that interfacial charge transfer occurs from Ni to Ce, leading to reduction in the valence state of Ce and increased formation of VO. This would optimize ΔGH* and facilitate the hydrogen evolution process, resulting in outstanding HER performance in 1 M KOH with a low overpotential of 99 mV at the current density of 10 mA•cm-2 and a modest Tafel slope of 78.4 mV•dec-1 for the NiO/CeO2 heterostructure sample. Therefore, the improved HER performance could be attributed to the synergistic coupling interactions and electron redistribution at the interface of NiO and CeO2. These results concretely demonstrate the direct determination of the interfacial structure of the heterostructure and provide atomistic insights to unravel the underlying mechanism of interfacial charge transfer induced HER performance improvement.

The Investigation of Hybrid PEDOT:PSS/ß-Ga2O3 Deep Ultraviolet Schottky Barrier Photodetectors.

In this paper, the hybrid ß-Ga2O3 Schottky diodes were fabricated with PEDOT:PSS as the anode. The electrical characteristics were investigated when the temperature changes from 298 K to 423 K. The barrier height ϕb increases, and the ideality factor n decreases as the temperature increases, indicating the presence of barrier height inhomogeneity between the polymer and ß-Ga2O3 interface. The mean barrier height and the standard deviation are 1.57 eV and 0.212 eV, respectively, after taking the Gaussian barrier height distribution model into account. Moreover, a relatively fast response speed of less than 320 ms, high reponsivity of 0.6 A/W, and rejection ratio of R254 nm/R400 nm up to 1.26 × 103 are obtained, suggesting that the hybrid PEDOT:PSS/ß-Ga2O3 Schottky barrier diodes can be used as deep ultraviolet (DUV) optical switches or photodetectors.

High-Voltage ß-Ga2O3 Schottky Diode with Argon-Implanted Edge Termination.

The edge-terminated Au/Ni/ß-Ga2O3 Schottky barrier diodes were fabricated by using argon implantation to form the high-resistivity layers at the periphery of the anode contacts. With the implantation energy of 50 keV and dose of 5 × 1014 cm-2 and 1 × 1016 cm-2, the reverse breakdown voltage increases from 209 to 252 and 451 V (the maximum up to 550 V) and the Baliga figure-of-merit (VBR2/Ron) also increases from 25.7 to 30.2 and 61.6 MW cm-2, about 17.5% and 140% enhancement, respectively. According to the 2D simulation, the electric fields at the junction corner are smoothed out after argon implantation and the position of the maximum breakdown electric filed, 5.05 MV/cm, changes from the anode corner at the interface to the overlap corner just under the implantation region. The temperature dependence of the forward characteristics was also investigated.

Experimental and Theoretical Studies of Mo/Au Schottky Contact on Mechanically Exfoliated ß-Ga2O3 Thin Film.

We studied the reverse current emission mechanism of the Mo/ß-Ga2O3 Schottky barrier diode through the temperature-dependent current-voltage (I-V) characteristics from 298 to 423 K. The variation of reverse current with the electric field indicates that the Schottky emission is the dominant carrier transport mechanism under reverse bias rather than the Frenkel-Poole trap-assisted emission model. Moreover, a breakdown voltage of 300 V was obtained in Fluorinert ambient with an average electric field of 3 MV/cm in Mo/ß-Ga2O3 Schottky barrier diode. The effects of the surface states, on the electric field distribution, were also analyzed by TCAD simulation. With the negative surface charge densities increasing, the peak electric field reduces monotonously. Furthermore, the Schottky barrier height inhomogeneity under forward bias was also discussed.