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Partial stability analysis of nonlinear time-varying impulsive systems

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International Journal of Biomathematics 2019年第6期12卷 73-98页

作者： Boulbaba Ghanmi Faculty of Sciences of Gafsa University of GafsaSidi Ahmed Zarroug 2112GafsaTunisia

This paper investigates the stability analysis with respect to part of the variables of nonlinear time-varying systems with impulse effect.The approach presented is based on the specially introduced piecewise continuous Lyapunov functions.The Lyapunov stability theorems with respect to part of the variables are generalized in the sense that the time derivatives of the Lyapunov functions are allowed to be indefinite.With the help of the notion of stable functions,asymptotic partial stability,exponential partial stability,input-to-state partial stability(ISPS)and integral input-to-state partial stability(iISPS)are considered.Three numerical examples are provided to illustrate the effectiveness of the proposed theoretical results.

关键词： Nonlinear impulsive systems partial stability piecewise continuous scalar functions indefinite Lyapunov function input-to-state partial stability(ISPS) integral input-to-state partial stability(iISPS).

Antimicrobial activity of Tunisian Euphorbia paralias L.

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Asian Pacific Journal of Tropical Biomedicine 2017年第7期7卷 629-632页

作者： Malek Besbes Hlila Kaouther Majouli Hichem Ben Jannet Mahjoub Aouni Maha Mastouri boulbaba Selmi Laboratory of Transmissible Diseases and Biological Active Substances Department of Pharmaceutical Sciences Faculty of Pharmacy University of Monastir Avenue Avicenne 5000 Monastir Tunisia Laboratory of Biochemistry Research Unit:UR 12ES08'Cell Signaling and Pathologies' Department of Biology Faculty of Medicine University of Monastir Monastir Tunisia Laboratory of Heterocyclic Chemistry Natural Products and Reactivity Team:Medicinal Chemistry and Natural Products Department of Chemistry Faculty of Sciences of Monastir University of Monastir Monastir Tunisia Laboratory of Bioresources:Integrative Biology and Exploiting Higher Institute of Biotechnology of Monastir Department of Molecular Biology Cellular and Biotechnology University of Monastir Monastir Tunisia

Objective: To examine the potential antimicrobial activity of Euphorbia paralias L.(Euphorbiaeae) leaves and stems extracts.Methods: The antimicrobial activity was tested against six microbial strains: Escherichia coli ATCC 8739, Bacillus subtilis ATCC 6633, Salmonella enterica CIP 8039, Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027 and Candida albicans ATCC 90028 by two different methods, the disk method and the dilution method.Results: Our results showed the important antimicrobial activity of the chloroform extract of the stems towards the majority of the strains by using both methods. Bacillus subtilis was the most sensitive strain(MIC = MBC = 15 mg/mL).Conclusion: Thus, some extracts of Euphorbia paralias can be used in the treatment of infectious diseases caused by microbes.

关键词：大戟属植物 paralias L. 抗菌剂活动 MIC MBC

Total phenolic compounds,antioxidant potential and α-glucosidase inhibition by Tunisian Euphorbia paralias L.

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Journal of Coastal Life Medicine 2016年第8期4卷 628-633页

作者： Malek Besbes Hlila Kaouther Majouli Fethia Harzallah Skhiri Hichem Ben Jannet Mahjoub Aouni Maha Mastouri boulbaba Selmi Laboratory of Transmissible Diseases and Biological Active Substances Faculty of PharmacyUniversity of MonastirAvenue Avicenne5000 MonastirTunisia Biochemistry Laboratory:Cell Signaling and Pathologies Research Unit:UR 12ES08Faculty of Medicine of MonastirTunisia Laboratory of Genetic Biodiversity and Valorisation of BioresourcesLR11ES41Higher Institute of Biotechnology of MonastirUniversity of MonastirMonastir 5000Tunisia Laboratory of Heterocyclic Chemistry Natural Products and ReactivityTeam:Medicinal Chemistry and Natural ProductsFaculty of Sciences of MonastirUniversity of MonastirMonastirTunisia Laboratory of Bioresources:Integrative Biology and exploiting Higher Institute of Biotechnology of MonastirMonastirTunisia

Objective:To examine the potential antioxidant and anti-α-glucosidase inhibitory activities of Tunisian Euphorbia paralias L.leaves and stems extracts and their composition of total polyphenol and flavonoids.Methods:The different samples were tested for their antiradical activities by using 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)and 1,1-diphenyl-2-picrylhydrazyl(DPPH)assays.Inα-glucosidase activity,α-glucosidase(0.3 IU/mL)and substrate,2500μmol/L p-nitrophenylα-D-glucopyranoside were used;absorbance was registered at 405 nm.Results:The leaves acetonic extract exhibited the strongestα-glucosidase inhibition[IC_(50)=(0.0035±0.001)μg/mL],which was 20-fold more active than the standard product(acarbose)[IC_(50)=(0.07±0.01)μg/mL].Acetonic extract of the leaves exhibited the highest quantity of total phenolic[(95.54±0.04)μg gallic acid equivalent/mg]and flavonoid[(55.16±0.25)μg quercetin equivalent/mg].The obtained findings presented also that this extract was detected with best antioxidant capacity[IC_(50)=(0.015±0.01)μg/mL]against DPPH and a value of IC_(50)equal to(0.02±0.01)μg/mL against ABTS.Positive relationship between polyphenolic content of the tested Euphorbia paralias L.leaves and stems extracts and its antioxidant activity(DPPH and ABTS)was detected.Elevated positive linear correlation was got between ABTS and total phenolic(R^(2)=0.751).Conclusions:The findings clearly demonstrate that the use of a polar solvent enables extraction of significant quantities of phenol compounds and flavonoids.

关键词： Euphorbia paralias L. Polyphenolic compounds Antioxidant activity Anti-α-glucosidase activity

Variations of Natural Soil Salinity in an Arid Environment Using Underground Watertable Effects on Salinization of Soils in Irrigated Perimeters in South Tunisia

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International Journal of Geosciences 2012年第5期3卷 1040-1047页

作者： Ajmi boulbaba Lazzez Marzouk Ramla ben Rabah Shimi Najet Faculty of Science of Tunis Department of Geology Tunis Tunisia Tunisian Oil Company Tunis Tunisia

In arid and semi-arid regions, salinity is a serious and chronic problem for agriculture. The aim of this study is to evaluate the hydromorphical and salinity risks, and to evaluate the relationship and the possible interfering between the water table and the soil on the oasis of Gabes. The topic is very important, especially for nations around the oceans in arid and semi-arid regions. The effect of the gypsum alkalinity in the soil salinity has investigated. The chemical characteristic of used water irrigation (salinity saturation) and their impact factor in the productivity area. Moreover, in this study the program of examination need to put fifteen piesometres by CRAD (Regional Commissariat of Agriculture Development) in the city of Gabes to controlling the variation of water levels in the superficial water table and their change chemical quality. The experimental measure of this program needs a yearly observation and investigation during April and May to evaluate the hydromorphical and salinity risks on the oasis of Gabes. The relationship and the possible interfering between the water table and the soil has evaluate in such condition.

关键词： Oasis Irrigation Water Superficial Water Table Salinity Drainage Tunisia