Molecularly specific detection towards trace nitrogen dioxide by utilizing Schottky-junction-based Gas Sensor.

Trace NO2 detection is essential for the production and life, where the sensing strategy is appropriate for rapid detection but lacks molecular specificity. This investigation proposes a sensing mechanism dominated by surface-scattering to achieve the molecularly-specific detection. Two-dimensional Bi2O2Se is firstly fabricated into a Schottky-junction-based gas-sensor. Applied with an alternating excitation, the sensor simultaneously outputs multiple response signals (i.e., resistance, reactance, and the impedance angle). Their response times are shorter than 200 s at room temperature. In NO2 sensing, these responses present the detection limit in ppt range and the sensitivity is up to 16.8 %·ppb-1. This NO2 sensitivity presents orders of magnitude higher than those of the common gases within the exhaled breath. The impedance angle is involved in the principle component analysis together with the other two sensing signals. Twelve kinds of typical gases containing NO2 are acquired with molecular characteristics. The change in dipole moment of the target molecule adsorbed is demonstrated to correlate with the impedance angle via surface scattering. The proposed mechanism is confirmed to output ultra-sensitive sensing responses with the molecular characteristic.

Research on Anti-inflammatory Targets and Mechanisms of alkaloids in Picrasma quassioides Benn Through Network Pharmacology

Abstract This study aimed to investigate the molecular mechanism of Picrasma quassioides Benn against inflammation by means of network pharmacology. The paper will provide a reference for multi-target and multi-channel treatment of inflammation with traditional Chinese medicine. Through screening and analysis, 11 active ingredients and 109 anti-inflammation prediction targets were obtained and constructed a compound-target network. The targets such as VEGFA, TLR4 and STAT3 may play a crucial role. Network enrichment analysis showed that the 109 potential targets constitute a number of pathways or inflammatory reactions closely related to inflammation, including NF-κB signaling pathway and MAPK signaling pathway. The docking results indicated that the binding energy of Picrasidine Y and the inflammatory factors VEGFA is the highest. This study predicted the role of multiple active compounds in the alkaloids of Picrasma in the inflammatory response, and provided a theoretical basis for the anti-inflammatory mechanism of Picrasma