Objective:To determine the chemical composition,total phenolic and total flavonoid contents ofthe crude extracts from leaves and stems of a Lebanese plantEuphorbia macroclada schyzoceras(E.macroclada),and to evaluate ...Objective:To determine the chemical composition,total phenolic and total flavonoid contents ofthe crude extracts from leaves and stems of a Lebanese plantEuphorbia macroclada schyzoceras(E.macroclada),and to evaluate their antioxidant potential using DPPH,H2O2,and chelating offerrous ions tests.Methods:Quantification of the total phenolic and total flavonoid contents ofthe crude extracts from leaves and stems and the antioxidant activities were evaluated usingspectrophotometric analyses.The chemical composition has been estimated using differenttechniques such as IR,LC/MS and NMR.Results:Ethanolic extract from leaves ofE.macroclada was better than aqueous extract and showed higher content in total phenolic and total flavonoidthan found in the stems.On the other hand,using DPPH and H2O2tests,this extract from leavesshowed higher antioxidant capacity than aqueous extract.However,using the chelating of ferrousions test,the antioxidant activity of the aqueous extract of both stems and leaves was strongerthan that of ethanolic once.The chemical composition of the whole plant showed the presence ofsome aromatic compounds and fatty acids.Conclusions:Both ethanolic and water extracts fromboth parts of this plant are effective and have good antioxidant power.So,this plant can be usedin the prevention of a number of diseases related to oxidative stress.展开更多
Acoustic sensing is nowadays a very demanding field which plays an important role in modern society, with applications spanning from structural health monitoring to medical imaging. Fiber-optics can bring many advanta...Acoustic sensing is nowadays a very demanding field which plays an important role in modern society, with applications spanning from structural health monitoring to medical imaging. Fiber-optics can bring many advantages to this field, and fiber-optic acoustic sensors show already performance levels capable of competing with the standard sensors based on piezoelectric transducers. This review presents the recent advances in the field of fiber-optic dynamic strain sensing, particularly for acoustic detection. Three dominant technologies are identified - fiber Bragg gratings, interferometric Mach-Zehnder, and Fabry-Perot configurations - and their recent developments are summarized.展开更多
基金Supported by Research Platform for Environmental Science,Lebanese UniversityThe grant is provided by the Lebanese University under the number ER019/UL/EDSTThis research was funded by Research Platform for Environmental Science,Lebanese University
文摘Objective:To determine the chemical composition,total phenolic and total flavonoid contents ofthe crude extracts from leaves and stems of a Lebanese plantEuphorbia macroclada schyzoceras(E.macroclada),and to evaluate their antioxidant potential using DPPH,H2O2,and chelating offerrous ions tests.Methods:Quantification of the total phenolic and total flavonoid contents ofthe crude extracts from leaves and stems and the antioxidant activities were evaluated usingspectrophotometric analyses.The chemical composition has been estimated using differenttechniques such as IR,LC/MS and NMR.Results:Ethanolic extract from leaves ofE.macroclada was better than aqueous extract and showed higher content in total phenolic and total flavonoidthan found in the stems.On the other hand,using DPPH and H2O2tests,this extract from leavesshowed higher antioxidant capacity than aqueous extract.However,using the chelating of ferrousions test,the antioxidant activity of the aqueous extract of both stems and leaves was strongerthan that of ethanolic once.The chemical composition of the whole plant showed the presence ofsome aromatic compounds and fatty acids.Conclusions:Both ethanolic and water extracts fromboth parts of this plant are effective and have good antioxidant power.So,this plant can be usedin the prevention of a number of diseases related to oxidative stress.
文摘Acoustic sensing is nowadays a very demanding field which plays an important role in modern society, with applications spanning from structural health monitoring to medical imaging. Fiber-optics can bring many advantages to this field, and fiber-optic acoustic sensors show already performance levels capable of competing with the standard sensors based on piezoelectric transducers. This review presents the recent advances in the field of fiber-optic dynamic strain sensing, particularly for acoustic detection. Three dominant technologies are identified - fiber Bragg gratings, interferometric Mach-Zehnder, and Fabry-Perot configurations - and their recent developments are summarized.
