Thermal analysis is one of the most used techniques for analyzing the behavior of aluminum alloys in order to analyze the precipitation of Guinier-Preston(GP)zones and different phases formed.In the present work,the b...Thermal analysis is one of the most used techniques for analyzing the behavior of aluminum alloys in order to analyze the precipitation of Guinier-Preston(GP)zones and different phases formed.In the present work,the behavior of the Al-5.46wt.%Zn-1.67wt.%Mg alloy was studied.The mechanism and kinetics of precipitation of the GP,the metastable phaseη′and the equilibrium phaseηwere investigated using DSC carried out between room temperature and 480℃at heating rates of 5,10,15 and 20℃/min.The apparent activation energies,calculated by DSC from isothermal calculation method using JMAK model,for GP,η′andηwere 56,79 and 96 kJ/mol,respectively,and those calculated by non-isothermal calculation method using Kissinger methods were 57,82 and 99 kJ/mol,respectively.The values of Avrami parameter,n,from isothermal calculation,during the precipitation of the GP,η′andηwere 1.103,1.9075 and 1.92,respectively,and those calculated by non-isothermal were 0.86,2.30 and 2.24,respectively.The results show that GP zones formation is governed by the migration of Zn and Mg atoms while the precipitation of theη′metastable phase and theηstable phase is governed by both the migration and the diffusion of the solute atoms.展开更多
Objective:To examine the in vitro antimicrobial activities of essential oil of the leaves of Eucalyptus globulus(E.globulus).Methods:The essential oils of this plant were obtained by the hydrodistillation method.The i...Objective:To examine the in vitro antimicrobial activities of essential oil of the leaves of Eucalyptus globulus(E.globulus).Methods:The essential oils of this plant were obtained by the hydrodistillation method.The inhibitory effects of this essential oil were tested against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)by using agar disc diffusion and dilution broth methods.Results:The results obtained showed that essential oil of the leaves of E.globulus has antimicrobial activity against gram negative bacteria(E.coli)as well as gram positive bacteria(S.aureus).Conclusion:The encouraging results indicate the essential oil of E.globulus leaves might be exploited as natural antibiotic for the treatment of several infectious diseases caused by these two germs,and could be useful in understanding the relations between traditional cures and current medicines.展开更多
Objective:To evaluate the in vitro antimicrobial activities of the crude oil of Eucalyptus camaldulensis(E.camaldulensis)leaves.Methods:The essential oils of E.camaldulensis harvested from the garden of the Health Cen...Objective:To evaluate the in vitro antimicrobial activities of the crude oil of Eucalyptus camaldulensis(E.camaldulensis)leaves.Methods:The essential oils of E.camaldulensis harvested from the garden of the Health Center in Sidi Bel Abbes city(North West of Algeria),were screened for their antibacterial activities against two clinical bacteria[Escherichia coli(E.coli),Staphylococcus aureus(S.aureus)]by the agar disc diffusion method and broth dilution susceptibility assay.Results:The diameter of zones of inhibition by the leaf extracts of E.camaldulensis was 10-31 mm and 10-26 mm respectively for E.coli and S.aureus.Gram positive S.aureus was more resistant to tested essential oil than Gram negative E.coli.Conclusions:The results suggested a potential antimicrobial activity of the essential oil of E.camaldulensis,which may find its application in future research for the food and pharmaceutical industry.展开更多
Background: Recent findings suggest the involvement of oxidative stress in the pathogenesis of chronic idiopathic urticaria (CIU). It has been demonstrated that desloratadine has an antioxidant activity in vitro. We e...Background: Recent findings suggest the involvement of oxidative stress in the pathogenesis of chronic idiopathic urticaria (CIU). It has been demonstrated that desloratadine has an antioxidant activity in vitro. We evaluated the effects of desloratadine on markers of oxidative stress in patients with CIU. Methods: Blood samples were obtained from 10 patients with CIU before and after 4 weeks oftreatment with desloratadine. Blood samples from 10 healthy volunteers were used as controls. In platelets from both patients and controls, radical oxygen species (ROS) production was measured using spectrofluorimetric detection of dichloro-fluorescein oxidation, and superoxide dismutase (SOD) activity was determined by means of the xanthine-xanthine oxidase system. Results: Radical oxygen species concentrations and SOD activity were significantly elevated in patients with CIU at baseline as compared with control subjects. Treatment with desloratadine caused a relevant reduction of ROS levels and SOD activity (P < 0.005). Conclusions: These preliminary results suggest that desloratadine exerts antioxidant effects also in vivo.展开更多
Objective:To examine the in vitro antimicrobial activities of essential oil of the needles of Pinus halepensis(P.halepensis).Methods:The antibacterial activity of essential oil of the needles of P.halepensis was deter...Objective:To examine the in vitro antimicrobial activities of essential oil of the needles of Pinus halepensis(P.halepensis).Methods:The antibacterial activity of essential oil of the needles of P.halepensis was determined using the agar well diffusion technique and disc diffusion method against Staphylococcus aureus ATCC 25923,and Escherichia coli ATCC 25922.Results:The diameter of zones of inhibition exhibited by the essential oil was between 6 and 17 mm.The essential oils was compared favorably with gentamycin used as a standard control.The minimum inhibitory concentration determined by the agar well diffusion method was 0.52 mg/mL for Staphylococcus aureus and 2.15 mg/mL for Escherichia coli.The minimum bactericidal concentration of the oils against the two microorganisms was 4.17 mg/mL.Conclusions:The results obtained from this study reveal that P.halepensis essential oils possess antibacterial activities and can be used as antimicrobial agents in the search for new drugs.展开更多
文摘Thermal analysis is one of the most used techniques for analyzing the behavior of aluminum alloys in order to analyze the precipitation of Guinier-Preston(GP)zones and different phases formed.In the present work,the behavior of the Al-5.46wt.%Zn-1.67wt.%Mg alloy was studied.The mechanism and kinetics of precipitation of the GP,the metastable phaseη′and the equilibrium phaseηwere investigated using DSC carried out between room temperature and 480℃at heating rates of 5,10,15 and 20℃/min.The apparent activation energies,calculated by DSC from isothermal calculation method using JMAK model,for GP,η′andηwere 56,79 and 96 kJ/mol,respectively,and those calculated by non-isothermal calculation method using Kissinger methods were 57,82 and 99 kJ/mol,respectively.The values of Avrami parameter,n,from isothermal calculation,during the precipitation of the GP,η′andηwere 1.103,1.9075 and 1.92,respectively,and those calculated by non-isothermal were 0.86,2.30 and 2.24,respectively.The results show that GP zones formation is governed by the migration of Zn and Mg atoms while the precipitation of theη′metastable phase and theηstable phase is governed by both the migration and the diffusion of the solute atoms.
文摘Objective:To examine the in vitro antimicrobial activities of essential oil of the leaves of Eucalyptus globulus(E.globulus).Methods:The essential oils of this plant were obtained by the hydrodistillation method.The inhibitory effects of this essential oil were tested against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)by using agar disc diffusion and dilution broth methods.Results:The results obtained showed that essential oil of the leaves of E.globulus has antimicrobial activity against gram negative bacteria(E.coli)as well as gram positive bacteria(S.aureus).Conclusion:The encouraging results indicate the essential oil of E.globulus leaves might be exploited as natural antibiotic for the treatment of several infectious diseases caused by these two germs,and could be useful in understanding the relations between traditional cures and current medicines.
基金Supported by Project(F03720120003)of Ministry of Higher Education&Scientific Research in Algeria.
文摘Objective:To evaluate the in vitro antimicrobial activities of the crude oil of Eucalyptus camaldulensis(E.camaldulensis)leaves.Methods:The essential oils of E.camaldulensis harvested from the garden of the Health Center in Sidi Bel Abbes city(North West of Algeria),were screened for their antibacterial activities against two clinical bacteria[Escherichia coli(E.coli),Staphylococcus aureus(S.aureus)]by the agar disc diffusion method and broth dilution susceptibility assay.Results:The diameter of zones of inhibition by the leaf extracts of E.camaldulensis was 10-31 mm and 10-26 mm respectively for E.coli and S.aureus.Gram positive S.aureus was more resistant to tested essential oil than Gram negative E.coli.Conclusions:The results suggested a potential antimicrobial activity of the essential oil of E.camaldulensis,which may find its application in future research for the food and pharmaceutical industry.
文摘Background: Recent findings suggest the involvement of oxidative stress in the pathogenesis of chronic idiopathic urticaria (CIU). It has been demonstrated that desloratadine has an antioxidant activity in vitro. We evaluated the effects of desloratadine on markers of oxidative stress in patients with CIU. Methods: Blood samples were obtained from 10 patients with CIU before and after 4 weeks oftreatment with desloratadine. Blood samples from 10 healthy volunteers were used as controls. In platelets from both patients and controls, radical oxygen species (ROS) production was measured using spectrofluorimetric detection of dichloro-fluorescein oxidation, and superoxide dismutase (SOD) activity was determined by means of the xanthine-xanthine oxidase system. Results: Radical oxygen species concentrations and SOD activity were significantly elevated in patients with CIU at baseline as compared with control subjects. Treatment with desloratadine caused a relevant reduction of ROS levels and SOD activity (P < 0.005). Conclusions: These preliminary results suggest that desloratadine exerts antioxidant effects also in vivo.
文摘Objective:To examine the in vitro antimicrobial activities of essential oil of the needles of Pinus halepensis(P.halepensis).Methods:The antibacterial activity of essential oil of the needles of P.halepensis was determined using the agar well diffusion technique and disc diffusion method against Staphylococcus aureus ATCC 25923,and Escherichia coli ATCC 25922.Results:The diameter of zones of inhibition exhibited by the essential oil was between 6 and 17 mm.The essential oils was compared favorably with gentamycin used as a standard control.The minimum inhibitory concentration determined by the agar well diffusion method was 0.52 mg/mL for Staphylococcus aureus and 2.15 mg/mL for Escherichia coli.The minimum bactericidal concentration of the oils against the two microorganisms was 4.17 mg/mL.Conclusions:The results obtained from this study reveal that P.halepensis essential oils possess antibacterial activities and can be used as antimicrobial agents in the search for new drugs.
