Sensing properties and mechanisms of LaF_(3)-Co_(3)O_(4) nanorods for low-concentration methanol detection

Methanol is one of the characteristic gases that distinguish between healthy individuals and lung cancer(LC)lesions in exhaled human breath.Its concentration in exhaled breath is generally below one part per million(1×10^(-6)).The second-phase composite is widely regarded as one of the methods to improve the gas-sensing perfor-mance of metal oxide semiconductor(MOS)materials.In this study,LaF_(3)-Co_(3)O_(4) was synthesized by a simple hydrothermal method to enhance its low-concentration methanol gas-sensing performance.5 at%LaF_(3)-Co_(3)O_(4) nanorods exhibited excellent methanol detection performance,including a wider linear detection concentration range(0.2×10^(-6)~5×10^(-6)),a response value exceeding 4.0 for 1×10^(-6)methanol at 275°C and 75%relative humidity(RH),long-term stability(maximum deviation within 15%over 2 weeks),and excellent selectivity.The mechanism of performance enhancement was studied using various techniques,and density functional theory.The special spinel structure of Co_(3)O_(4),the high ionic migration of F-in LaF_(3),the larger specific surface area of 5 at%LaF_(3)-Co_(3)O_(4) nanorods,and the generated crystal defects all explain the excellentmethanol gas-sensing property.This work provides a novel route to prepare MOS composite materials for low-concentration methanol gas detection.

Interface engineering of ZnSnO_(3)-based heterojunctions for room-temperature methanol monitoring

Detecting methanol is of great importance in the organic synthesis industry.Herein,the effective utilization of ZnSnO_(3)-based microstructures for room-temperature methanol monitoring was realized through a template-free approach.ZnSnO_(3)-based heterojunctions with different structures and morphologies were successfully synthesized via regulating the molar ratio of Zn2+and Sn4+sources.And room-temperature sensing properties towards methanol were investigated.Among them,ZnO/ZnSnO_(3) hollow microcubes exhibited an outstanding sensing performance including a high sensitivity(10.16)and a response/recovery time(14/75 s)and a limit of detection(490×10^(-9))towards 5×10^(-6)methanol.Additionally,the synergistic effects of hollow structure with larger specific surface areas(42.277 m^(2)·g^(-1)),the construction of n-n heterojunctions formed at ZnSnO_(3) and ZnO interfaces,the high percentage of dissociative and chemisorbed oxygen are the main causes of the elevated sensing characteristics.Besides,the practical experiment demonstrated that ZnO/ZnSnO_(3) was capable of on-field monitoring methanol in the chemical reaction utilizing H_(2) and CO_(2) as raw materials.Moreover,with the help of density functional theory calculations,the enhanced sensing properties of ZnO/ZnSnO_(3) are due to the special tuning effects of Zn ionic sites on methanol adsorption.

Screening of Eleven Commonly Used Traditional Chinese Medicines for Inhibitory Effects on Human Cytochrome P450 Enzymes

Objective Traditional Chinese medicines（TCMs） as natural therapeutic agents have been widely used and received great attention over the world.However,the information on them to cause herb-drug interactions mediated by cytochrome P450（CYP） enzymes is limited.The present study aims to evaluate the inhibitory effects of 11 commonly used TCMs,including Nelumbinis Folium,Ginseng Radix et Rhizoma,Ziziphi Spinosae Semen,Chrysanthemi Flos,Lonicera Japonica Flos,Lycii Fructus,Cassiae Semen,Poria,Crataegi Fructus,Schisandrae Chinensis Fructus,and Polygonati Rhizoma,on the five human major CYP isoenzymes 2C19,2D6,3A4,2E1,and 2C9.Methods An in vitro cocktail method was used.Results The aqueous extracts of all tested TCMs were found no significant inhibitory effect,with IC50 values higher than 100 μg/mL while,the ethanolic extracts of some herbs showed more potent inhibition.These herbs include Nelumbinis Folium with IC50 values of 1 2.05 and 61.43 μg/mL on CYP2D6 and CYP2E1,Schisandrae Chinensis Fructus with IC50 values of 64.42 and 47.24 μg/mL on CYP2C1 9and CYP3A4,and Chrysanthemi Flos with IC50 values of 45.25 μg/mL on CYP2C9,respectively.Conclusion Co-administration of these TCMs and their products with conventional medicines should be paid much attention to,and their potential inhibitory effects on CYP enzyme activities need to be further investigated.