Mosquitoes(Diptera:Culicidae)are vectors of various pathogens of public health concern,but replacing conventional insecticides remains a challenge.In this regard,natural products represent valuable sources of potentia...Mosquitoes(Diptera:Culicidae)are vectors of various pathogens of public health concern,but replacing conventional insecticides remains a challenge.In this regard,natural products represent valuable sources of potential insecticidal compounds,thus increasingly attracting research interest.Commiphora myrrha(T.Nees)Engl.(Burseraceae)is a medicinal plant whose oleo-gum resin is used in food,cosmetics,fragrances,and pharmaceuticals.Herein,the larvicidal potential of its essential oil(EO)was assessed on four mosquito species(Aedes albopictus Skuse,Ae.aegypti L.,Anopheles gambiae Giles and An.stephensi Liston),with LC_(50) values ranging from 4.42 to 16.80 μg/mL.The bio-guided EO fractionation identified furanosesquiterpenes as the main larvicidal compounds.A GC-MS-driven untargeted metabolomic analysis revealed 32 affected metabolic pathways in treated larvae.The EO non-target toxicity on Daphnia magna Straus(LC_(50)=4.51 μL/L)and its cytotoxicity on a human kidney cell line(HEK293)(IC50 of 14.38 μg/mL)were also assessed.This study shows the potential of plant products as innovative insecticidal agents and lays the ground-work for the possible exploitation of C.myrrha EO in the sustainable approaches for mosquito management.展开更多
A joint international effort to improve solid propellant performance within the framework of a FP7European Project was described.Several metallized solid rocket propellants,of the broad family AP/HTPB/Metal in the rat...A joint international effort to improve solid propellant performance within the framework of a FP7European Project was described.Several metallized solid rocket propellants,of the broad family AP/HTPB/Metal in the ratio 68/14/18,were experimentally analyzed seeking to optimize the delivered specific impulse by identifying the most suitable high-energy fuel.Keeping the same nominal composition,different metallic fuels(including micrometric and nanometric Al,AlH3,and a variety of dual metal compositions)were characterized,tested,and contrasted to a conventional micrometric aluminum(30μm average grain size)certified for space flights.In order to overcome the intrinsic performance limitations of the matrix AP/HTPB,a new matrix consisting of ADN/GAP satisfying also the need for environmentally benign propellant formulation was considered as well.A comparative analysis between the two solid propellant systems in terms of ideal thermochemistry and experimental combustion properties reveals advantages and disadvantages of both.Overall,it is judged worthwhile to develop ADN/GAP propellants,with or without metallic fuels,to enhance the current status of solid rocket propulsion.Controlling morphology and mechanical properties of ADN/GAP compositions and understanding their flame structure and aggregation/agglomeration properties are the main issues still challenging industrial users.展开更多
Several metallized solid rocket propellants,AP/Metal/HTPB in the ratio 68/18/14,were experimentally analyzed at the Space Propulsion Laboratory of Politecnico di Milano.Effects of the metals(micrometric and nanometric...Several metallized solid rocket propellants,AP/Metal/HTPB in the ratio 68/18/14,were experimentally analyzed at the Space Propulsion Laboratory of Politecnico di Milano.Effects of the metals(micrometric and nanometric Al,B,Mg,and a variety of dual metals) on the performance of the propellant were studied and contrasted to a conventional micrometric aluminum(30 μm average grain size) taken as reference.It is shown that the propellant microstructure plays a fundamental role in controlling the critical aggregation/agglomeration phenomena occurring below and near the burning surface.Two specific effects of microstructure in terms of steady burning rate and average agglomerate size are illustrated.展开更多
Objective: To evaluate the anticonvulsant effect of the essential oil of Myrothamnus moschatus(M. moschatus) in convulsion induced by pentylenetetrazole and picrotoxin in rodent models.Methods: The essential oil of th...Objective: To evaluate the anticonvulsant effect of the essential oil of Myrothamnus moschatus(M. moschatus) in convulsion induced by pentylenetetrazole and picrotoxin in rodent models.Methods: The essential oil of the aerial parts of M. moschatus was extracted by steam distillation. Thereafter, it was injected subcutaneously to rats and mice at escalating doses(0.1–0.8 m L/kg). Ten minutes after drug injection, pentylenetetrazole was injected intraperitoneally to rats and picrotoxin was administered to mice by the same route.Diazepam served as the positive control. Every single animal was placed into transparent cage and observed for convulsive behavior for 30 min by using ordinary security cameras connected to a video recorder. Death occurring for a period of 24 h was also recorded.Results: The essential oil at 0.8 m L/kg completely arrested the pentylenetetrazole-induced convulsion without any sedative effect and delayed its appearance at lower doses, but showed moderate activities on picrotoxin-induced convulsion. For the rats treated with pentylenetetrazole alone, the mortality was 100% within 1 h, but for the rats pre-treated with the essential oil, the mortality was 0%. For the mice treated with picrotoxin, the mortality rate was also 100%, while 20%–100% died in those that had been pre-treated with the oil.Conclusions: The results confirmed at least partly the traditional uses of the smoke of M. moschatus for the management of convulsion, and implied that the essential oil may inhibit the convulsion by GABAergic neuromodulation.展开更多
Coffee arabica L.is an economical crop cultivated in many countries including Yemen.The present study evaluated the phytochemical contents of the methanolic extracts,prepared by maceration,of six Yemeni green coffee b...Coffee arabica L.is an economical crop cultivated in many countries including Yemen.The present study evaluated the phytochemical contents of the methanolic extracts,prepared by maceration,of six Yemeni green coffee beans varieties namely Esmaeli,Hamadi,Harazi,Mattari,Odaini and Yafei.Antioxidant(phosphomolybdenum,antiradical,reducing power and ferrous chelating),and enzyme inhibition activity of the extracts against acetylcholinesterase butyrylcholinesterase,tyrosinase,α-glucosidase,andα-amylase were also studied.Quantification of total phenols revealed that all green beans varieties were richer in their total polyphenolic(63.77-110.98 mg gallic acid equivalent per g of extract)content than their flavonoids one(2.86-5.57 mg rutin equivalent per g of extract).HPLC-MS/MS analysis of 30 selected bioactive compounds showed that all varieties had the same types of phytoconstituents with differences in their relative abundance.Caffeine(1613.89-2466.38μg/g)followed by 5-caffeoylquinic acid(1017.63-1313.39μg/g)were the dominant compounds in all varieties with caffeine more abundant in Esmaeli variety while 5-caffeoylquinic acid in Odaini variety.All varieties displayed a pronounced antioxidant property in all the in vitro assays with Odaini variety significantly(p<0.05)exerted the highest anti-DPPH radicals(253.96 mg Trolox equivalent(TE)/g),metal chelating(19.73 mg Disodium edetate equivalents/g),Cu^(2+)(441.11 mg TE/g)and Fe3+(221.04 mg TE/g)reducing activities.Furthermore,the majority of green coffee beans varieties showed comparable enzyme inhibition property with highest activity recorded against tyrosinase(39.35-46.96 mg kojic acid equivalents/g)and acetylcholinesterase(1.80-2.17 mg galanthamine equivalents/g)enzymes.In conclusion,all Yemeni green coffee beans varieties have proven to be rich source of biochemicals with beneficial impact on human health and could be of significant applications in food,pharmaceutical and cosmetics industry.展开更多
基金granted by the project PRIN 2022“Bioformulations for controlled release of botanical pesticides for sustainable agriculture”(prot.202274BK9L)supported by the Italian Ministry of University and Research(MUR)the Technology agency of the Czech Republic for its financial support concerning botanical pesticide(Project No.FW06010376).
文摘Mosquitoes(Diptera:Culicidae)are vectors of various pathogens of public health concern,but replacing conventional insecticides remains a challenge.In this regard,natural products represent valuable sources of potential insecticidal compounds,thus increasingly attracting research interest.Commiphora myrrha(T.Nees)Engl.(Burseraceae)is a medicinal plant whose oleo-gum resin is used in food,cosmetics,fragrances,and pharmaceuticals.Herein,the larvicidal potential of its essential oil(EO)was assessed on four mosquito species(Aedes albopictus Skuse,Ae.aegypti L.,Anopheles gambiae Giles and An.stephensi Liston),with LC_(50) values ranging from 4.42 to 16.80 μg/mL.The bio-guided EO fractionation identified furanosesquiterpenes as the main larvicidal compounds.A GC-MS-driven untargeted metabolomic analysis revealed 32 affected metabolic pathways in treated larvae.The EO non-target toxicity on Daphnia magna Straus(LC_(50)=4.51 μL/L)and its cytotoxicity on a human kidney cell line(HEK293)(IC50 of 14.38 μg/mL)were also assessed.This study shows the potential of plant products as innovative insecticidal agents and lays the ground-work for the possible exploitation of C.myrrha EO in the sustainable approaches for mosquito management.
基金supported by the HISP project(High performance solid propellants for In-Space Propulsion)of the European Community′s Seventh Framework Programme(FP7/2007-2013), under Grant Agreement No.262099,coordinated by FOI
文摘A joint international effort to improve solid propellant performance within the framework of a FP7European Project was described.Several metallized solid rocket propellants,of the broad family AP/HTPB/Metal in the ratio 68/14/18,were experimentally analyzed seeking to optimize the delivered specific impulse by identifying the most suitable high-energy fuel.Keeping the same nominal composition,different metallic fuels(including micrometric and nanometric Al,AlH3,and a variety of dual metal compositions)were characterized,tested,and contrasted to a conventional micrometric aluminum(30μm average grain size)certified for space flights.In order to overcome the intrinsic performance limitations of the matrix AP/HTPB,a new matrix consisting of ADN/GAP satisfying also the need for environmentally benign propellant formulation was considered as well.A comparative analysis between the two solid propellant systems in terms of ideal thermochemistry and experimental combustion properties reveals advantages and disadvantages of both.Overall,it is judged worthwhile to develop ADN/GAP propellants,with or without metallic fuels,to enhance the current status of solid rocket propulsion.Controlling morphology and mechanical properties of ADN/GAP compositions and understanding their flame structure and aggregation/agglomeration properties are the main issues still challenging industrial users.
基金supported by CNES(under Commande No.4700024752/DLA090 and No.4700028003/DLA094)
文摘Several metallized solid rocket propellants,AP/Metal/HTPB in the ratio 68/18/14,were experimentally analyzed at the Space Propulsion Laboratory of Politecnico di Milano.Effects of the metals(micrometric and nanometric Al,B,Mg,and a variety of dual metals) on the performance of the propellant were studied and contrasted to a conventional micrometric aluminum(30 μm average grain size) taken as reference.It is shown that the propellant microstructure plays a fundamental role in controlling the critical aggregation/agglomeration phenomena occurring below and near the burning surface.Two specific effects of microstructure in terms of steady burning rate and average agglomerate size are illustrated.
基金Supported by the University Research Fund 2014/2015 of the University of Camerino under the grant number FPI000044
文摘Objective: To evaluate the anticonvulsant effect of the essential oil of Myrothamnus moschatus(M. moschatus) in convulsion induced by pentylenetetrazole and picrotoxin in rodent models.Methods: The essential oil of the aerial parts of M. moschatus was extracted by steam distillation. Thereafter, it was injected subcutaneously to rats and mice at escalating doses(0.1–0.8 m L/kg). Ten minutes after drug injection, pentylenetetrazole was injected intraperitoneally to rats and picrotoxin was administered to mice by the same route.Diazepam served as the positive control. Every single animal was placed into transparent cage and observed for convulsive behavior for 30 min by using ordinary security cameras connected to a video recorder. Death occurring for a period of 24 h was also recorded.Results: The essential oil at 0.8 m L/kg completely arrested the pentylenetetrazole-induced convulsion without any sedative effect and delayed its appearance at lower doses, but showed moderate activities on picrotoxin-induced convulsion. For the rats treated with pentylenetetrazole alone, the mortality was 100% within 1 h, but for the rats pre-treated with the essential oil, the mortality was 0%. For the mice treated with picrotoxin, the mortality rate was also 100%, while 20%–100% died in those that had been pre-treated with the oil.Conclusions: The results confirmed at least partly the traditional uses of the smoke of M. moschatus for the management of convulsion, and implied that the essential oil may inhibit the convulsion by GABAergic neuromodulation.
基金The authors are thankful to the research supporting project number(RSP-2021/86),King Saud University,Riyadh,Saudi Arabia.
文摘Coffee arabica L.is an economical crop cultivated in many countries including Yemen.The present study evaluated the phytochemical contents of the methanolic extracts,prepared by maceration,of six Yemeni green coffee beans varieties namely Esmaeli,Hamadi,Harazi,Mattari,Odaini and Yafei.Antioxidant(phosphomolybdenum,antiradical,reducing power and ferrous chelating),and enzyme inhibition activity of the extracts against acetylcholinesterase butyrylcholinesterase,tyrosinase,α-glucosidase,andα-amylase were also studied.Quantification of total phenols revealed that all green beans varieties were richer in their total polyphenolic(63.77-110.98 mg gallic acid equivalent per g of extract)content than their flavonoids one(2.86-5.57 mg rutin equivalent per g of extract).HPLC-MS/MS analysis of 30 selected bioactive compounds showed that all varieties had the same types of phytoconstituents with differences in their relative abundance.Caffeine(1613.89-2466.38μg/g)followed by 5-caffeoylquinic acid(1017.63-1313.39μg/g)were the dominant compounds in all varieties with caffeine more abundant in Esmaeli variety while 5-caffeoylquinic acid in Odaini variety.All varieties displayed a pronounced antioxidant property in all the in vitro assays with Odaini variety significantly(p<0.05)exerted the highest anti-DPPH radicals(253.96 mg Trolox equivalent(TE)/g),metal chelating(19.73 mg Disodium edetate equivalents/g),Cu^(2+)(441.11 mg TE/g)and Fe3+(221.04 mg TE/g)reducing activities.Furthermore,the majority of green coffee beans varieties showed comparable enzyme inhibition property with highest activity recorded against tyrosinase(39.35-46.96 mg kojic acid equivalents/g)and acetylcholinesterase(1.80-2.17 mg galanthamine equivalents/g)enzymes.In conclusion,all Yemeni green coffee beans varieties have proven to be rich source of biochemicals with beneficial impact on human health and could be of significant applications in food,pharmaceutical and cosmetics industry.
