Effects of Crop Stubble on Physicochemical Properties of Continuous Cropping Soil and Cucumber Yield and Quality

By a pot experiment, two kinds of crop stubble (wheat, soybean) were added into continuous cropping soil of cucumber according to different quantity (0.5%, 1% and 2%), the effects of different kinds of stubble and quantity on the continuous cropping soil and growth of cucumber were investigated. The results showed that two kinds of crop stubble significantly decreased soil bulk density, and increased total porosity of soil. Each of all treatments significantly decreased the accumulation of salinity in soil within the entire growth period of cucumber. 2% wheat stubble treatment had the biggest drop in soil EC in the later period of cucumber growth. Soybean stubble treatment had the lesser effect on soil EC. Wheat and soybean stubble promoted the growth of cucumber, increased the yield of cucumber, and improved the quality of cucumber. 2% of wheat stubble treatment had a biggest increase in cucumber yield, which increased the yield by 34.23% compared with the control.

Fast-response fluorescent probe with favorable water solubility for highly sensitive imaging of endogenous tyrosinase in living cells and zebrafish model

Tyrosinase(TYR) is an important polyphenolic oxidase enzyme and usually regards as a biomarker of melano ma cancer.Highly effective tracking TYR activity in vivo will help to study the mechanism of TYR in living organisms and forecasts related diseases.In this study,we present a novel TYR-activatable fluo rescent probe(CHMC-DOPA) for tracking TYR activity in vitro and in vivo.CHMC-DOPA is constructed by incorporating dopamine(DOPA) moiety into a fluorescent chloro-hydroxyl-merocyanine(CHMC)scaffold.Upon exposure to TYR,the dopamine unit in CHMC-DOPA is oxidized to a dopaquinone derivative,and an intramolecular photo-induced electron transfer(PET) process between CHMC fluorophore and o-dopaquinone will take place,the fluorescence of CHMC-DOPA is quenched rapidly.Therefore,the evaluation of TYR activity is established in terms of the relationship between fluorescence quenching efficiency and TYR activity.In our experiments,CHMC-DOPA shows various advantages,such as fast response(8 min),low concentration of TYR activation(0.5 U/mL),good water-solubility,as well as the lowest detection limit(0.003 U/mL) compared with previously reported works.Furthermore,CHMCDO PA also exhibits excellent cell membrane permeability and low cytotoxicity,which is successfully used to monitor endogenous TYR activity in living cancer cells and zebrafish models.CHMC-DOPA performs well,and we anticipate that this newly designed novel platform will provide an alternative for high effective monitoring TYR activity in biosystems.

External-Oxidant-Free Electrochemical Oxidative Trifluoromethylation of Arenes Using CF3SO2Na as the CF3 Source

Summary of main observation and conclusion An efficient and environmentally benign electrochemical oxidative radical C-H trifluoromethylation of arenes by employing Langlois reagent as the CF3 source was developed in this work.Neither transition metal catalysts nor external chemical oxidants were required in this trifluoromethylation process.The reaction could be conducted in gram scale with high reaction efficiency.