New radiolarian ages show that the island arc-related Acoje block of the Zambales Ophiolite Complex is possibly of Late Jurassic to Early Cretaceous age.Radiometric dating of its plutonic and volcanichypabyssal rocks ...New radiolarian ages show that the island arc-related Acoje block of the Zambales Ophiolite Complex is possibly of Late Jurassic to Early Cretaceous age.Radiometric dating of its plutonic and volcanichypabyssal rocks yielded middle Eocene ages.On the other hand,the paleontological dating of the sedimentary carapace of the transitional mid-ocean ridge-island arc affiliated Coto block of the ophiolite complex,together with isotopic age datings of its dikes and mafic cumulate rocks,also yielded Eocene ages.This offers the possibility that the Zambales Ophiolite Complex could have:(1)evolved from a Mesozoic arc(Acoje block)that split to form a Cenozoic back-arc basin(Coto block),(2)through faulting,structurally juxtaposed a Mesozoic oceanic crust with a younger Cenozoic lithospheric fragment or(3)through the interplay of slab rollback,slab break-off and,at a later time,collision with a microcontinent fragment,caused the formation of an island arc-related ophiolite block(Acoje)that migrated trench-ward resulting into the generation of a back-arc basin(Coto block)with a limited subduction signature.This Meso-Cenozoic ophiolite complex is compared with the other oceanic lithosphere fragments along the western seaboard of the Philippines in the context of their evolution in terms of their recognized environments of generation.展开更多
The proto-Philippine Sea Plate(pPSP)has been proposed by several authors to account for the origin of the Mesozoic supra-subduction ophiolites along the Philippine archipelago.In this paper,a comprehensive review of t...The proto-Philippine Sea Plate(pPSP)has been proposed by several authors to account for the origin of the Mesozoic supra-subduction ophiolites along the Philippine archipelago.In this paper,a comprehensive review of the ophiolites in the eastern portion of the Philippines is undertaken.Available data on the geology,ages and geochemical signatures of the oceanic lithospheric fragments in Luzon(Isabela,Lagonoy in Camarines Norte,and Rapu-Rapu island),Central Philippines(Samar,Tacloban,Malitbog and Southeast Bohol),and eastern Mindanao(Dinagat and Pujada)are presented.Characteristics of the Halmahera Ophiolite to the south of the Philippines are also reviewed for comparison.Nearly all of the crust-mantle sequences preserved along the eastern Philippines share Early to Late Cretaceous ages.The geochemical signatures of mantle and crustal sections reflect both mid-oceanic ridge and suprasubduction signatures.Although paleomagnetic information is currently limited to the Samar Ophiolite,results indicate a near-equatorial Mesozoic supra-subduction zone origin.In general,correlation of the crust-mantle sequences along the eastern edge of the Philippines reveal that they likely are fragments of the Mesozoic pPSP.展开更多
A number of geological studies have already been conducted on the Zambales Ophiolite Complex(ZOC), a north-south trending complete ophiolite sequence exposed in the western portion of Central Luzon, Philippines.Previo...A number of geological studies have already been conducted on the Zambales Ophiolite Complex(ZOC), a north-south trending complete ophiolite sequence exposed in the western portion of Central Luzon, Philippines.Previous works recognized the ZOC as being made up of two blocks,展开更多
Utilization of polyethyleneglycol （PEG） functionalized zinc phthalocyanine, （PEG）4ZnPc in （i） singlet oxygen generation, and （ii） in building energy harvesting donor-acceptor systems using fullerene, C60 as an...Utilization of polyethyleneglycol （PEG） functionalized zinc phthalocyanine, （PEG）4ZnPc in （i） singlet oxygen generation, and （ii） in building energy harvesting donor-acceptor systems using fullerene, C60 as an acceptor via the well-known metal-ligand axial coordination approach is reported. The （PEG）4ZnPe was found to be capable of producing singlet oxygen with a quantum yield, ooa of 0.77 in toluene, a value higher than that obtained for pristine （t-bu）4ZnPc （φ△=0.54） carrying no PEG groups, revealing its usefulness in photodynamic therapy applications. Spectroscopic studies revealed efficient binding of phenylimidazole functionalized fullerene, C60 Im with l ： 1 stoichiometry to （PEG）4ZnPc. Binding constant K for the formation of （PEG）4ZnPc：ImC60 dyad was found to be 6 × 103 M 1 revealing moderate stability. Geometric and electronic studies of the dyad was arrived by B3LYP/3-21G（＊） method. The HOMO level was found to be on zinc phthalocyanine entity while the LUMO level was found to be on the C60 entity suggesting formation of （PEG）4ZnPc＊＋：ImC60＊ charge separated state during the process of electron transfer reaction. Redox studies on the （PEG）4ZnPc：ImC60 dyad enabled accurate determination of the oxidation and reduction potentials of the donor-acceptor system, and to evaluate free-energy changes associated for the charge separation process. Kinetics of photoinduced charge separation and recombination in the （PEG）4ZnPc：ImC60 dyad was investigated using femtosecond transient absorption studies. Relatively long-lived charge separated states were confirmed for the dyad suggesting their potential usefulness in energy harvesting applications.展开更多
Objective:To screen for larvicidal activity of aqueous and ethanolic extracts(95%ethanol)from Selaginella elmeri,Christella dentata,Elatostema sinnatum,Curculigo capitulata,Euphorbia hirta,Murraya koenigii(M.koenigii)...Objective:To screen for larvicidal activity of aqueous and ethanolic extracts(95%ethanol)from Selaginella elmeri,Christella dentata,Elatostema sinnatum,Curculigo capitulata,Euphorbia hirta,Murraya koenigii(M.koenigii),Alpinia speciosa,Cymbopogon citratus,Eucalyptus globulus(E.globulus),Jatropha curcas(J.curcas),Psidium guajava,Gliricidia sepium,Ixora coccinea and Capsicum frutescens(C.frutescens)against Aedes aegypti(A.aegypti)and Aedes albopictus(A.albopictus)3rd instar larvae.Methods:Ethanolic and aqueous extracts were screened for larvicidal activity by exposing the A.aegypti and A.albopictus 3rd instar larvae(15 larvae per trial,triplicates)for 48 h,counting the mortalities every 24 h.Additionally,phytochemical screening for flavonoids,tannins,alkaloids,anthraquinones,anthrones,coumarins,indoles and steroids were performed on active extracts using spray tests.Results:Against A.aegypti,the three most active extracts were C.frutescens ethanolic(100%after 24 and 48 h),J.curcas ethanolic(84.44%after 24 h and 88.89%after 48 h)and M.koenigii ethanolic(53.33%after 24 h and 71.11%after 48 h).On the other hand,against A.albopictus,the three most active extracts were C.frutescens ethanolic(93.33%after 24 h and 100%after 48 h),J.curcas ethanolic(77.78%after 24 h and 82.22%after 48 h)and E.globulus ethanolic(64.44%after 24 h and 73.33%after 48 h).Phytochemical screening was also performed on the active extracts,revealing alkaloids,tannins,indoles and steroids.Conclusios:The results demonstrate the larvicidal activities of ethanolic extracts of Cymbopogon citratus,Euphorbia hirta,Ixora coccinea,Gliricidia sepium,M.koenigii,E.globulus,J.curcas and C.frutescens against A.aegypti and A.albopictus 3rd instar larvae.These could be used as potential larvicidal agents for the control of these mosquitoes.展开更多
基金support from the University of the PhilippinesNational Institute of Geological Sciencesfinancial support from the Department of Science and Technology through the years
文摘New radiolarian ages show that the island arc-related Acoje block of the Zambales Ophiolite Complex is possibly of Late Jurassic to Early Cretaceous age.Radiometric dating of its plutonic and volcanichypabyssal rocks yielded middle Eocene ages.On the other hand,the paleontological dating of the sedimentary carapace of the transitional mid-ocean ridge-island arc affiliated Coto block of the ophiolite complex,together with isotopic age datings of its dikes and mafic cumulate rocks,also yielded Eocene ages.This offers the possibility that the Zambales Ophiolite Complex could have:(1)evolved from a Mesozoic arc(Acoje block)that split to form a Cenozoic back-arc basin(Coto block),(2)through faulting,structurally juxtaposed a Mesozoic oceanic crust with a younger Cenozoic lithospheric fragment or(3)through the interplay of slab rollback,slab break-off and,at a later time,collision with a microcontinent fragment,caused the formation of an island arc-related ophiolite block(Acoje)that migrated trench-ward resulting into the generation of a back-arc basin(Coto block)with a limited subduction signature.This Meso-Cenozoic ophiolite complex is compared with the other oceanic lithosphere fragments along the western seaboard of the Philippines in the context of their evolution in terms of their recognized environments of generation.
基金Funding support from the Department of Science and Technology,University of the Philippines-Diliman,National Institute of Geological Sciences and National Research Council of the Philippines
文摘The proto-Philippine Sea Plate(pPSP)has been proposed by several authors to account for the origin of the Mesozoic supra-subduction ophiolites along the Philippine archipelago.In this paper,a comprehensive review of the ophiolites in the eastern portion of the Philippines is undertaken.Available data on the geology,ages and geochemical signatures of the oceanic lithospheric fragments in Luzon(Isabela,Lagonoy in Camarines Norte,and Rapu-Rapu island),Central Philippines(Samar,Tacloban,Malitbog and Southeast Bohol),and eastern Mindanao(Dinagat and Pujada)are presented.Characteristics of the Halmahera Ophiolite to the south of the Philippines are also reviewed for comparison.Nearly all of the crust-mantle sequences preserved along the eastern Philippines share Early to Late Cretaceous ages.The geochemical signatures of mantle and crustal sections reflect both mid-oceanic ridge and suprasubduction signatures.Although paleomagnetic information is currently limited to the Samar Ophiolite,results indicate a near-equatorial Mesozoic supra-subduction zone origin.In general,correlation of the crust-mantle sequences along the eastern edge of the Philippines reveal that they likely are fragments of the Mesozoic pPSP.
文摘A number of geological studies have already been conducted on the Zambales Ophiolite Complex(ZOC), a north-south trending complete ophiolite sequence exposed in the western portion of Central Luzon, Philippines.Previous works recognized the ZOC as being made up of two blocks,
基金Support by the National Science Foundation （Grant No. 1401188） is acknowledged. The computational work was performed at the Holland Computing Centre of the University of Nebraska.
文摘Utilization of polyethyleneglycol （PEG） functionalized zinc phthalocyanine, （PEG）4ZnPc in （i） singlet oxygen generation, and （ii） in building energy harvesting donor-acceptor systems using fullerene, C60 as an acceptor via the well-known metal-ligand axial coordination approach is reported. The （PEG）4ZnPe was found to be capable of producing singlet oxygen with a quantum yield, ooa of 0.77 in toluene, a value higher than that obtained for pristine （t-bu）4ZnPc （φ△=0.54） carrying no PEG groups, revealing its usefulness in photodynamic therapy applications. Spectroscopic studies revealed efficient binding of phenylimidazole functionalized fullerene, C60 Im with l ： 1 stoichiometry to （PEG）4ZnPc. Binding constant K for the formation of （PEG）4ZnPc：ImC60 dyad was found to be 6 × 103 M 1 revealing moderate stability. Geometric and electronic studies of the dyad was arrived by B3LYP/3-21G（＊） method. The HOMO level was found to be on zinc phthalocyanine entity while the LUMO level was found to be on the C60 entity suggesting formation of （PEG）4ZnPc＊＋：ImC60＊ charge separated state during the process of electron transfer reaction. Redox studies on the （PEG）4ZnPc：ImC60 dyad enabled accurate determination of the oxidation and reduction potentials of the donor-acceptor system, and to evaluate free-energy changes associated for the charge separation process. Kinetics of photoinduced charge separation and recombination in the （PEG）4ZnPc：ImC60 dyad was investigated using femtosecond transient absorption studies. Relatively long-lived charge separated states were confirmed for the dyad suggesting their potential usefulness in energy harvesting applications.
基金Supported by the National Institutes of Health,University of the Philippines Manila(Grant No.2014-017).
文摘Objective:To screen for larvicidal activity of aqueous and ethanolic extracts(95%ethanol)from Selaginella elmeri,Christella dentata,Elatostema sinnatum,Curculigo capitulata,Euphorbia hirta,Murraya koenigii(M.koenigii),Alpinia speciosa,Cymbopogon citratus,Eucalyptus globulus(E.globulus),Jatropha curcas(J.curcas),Psidium guajava,Gliricidia sepium,Ixora coccinea and Capsicum frutescens(C.frutescens)against Aedes aegypti(A.aegypti)and Aedes albopictus(A.albopictus)3rd instar larvae.Methods:Ethanolic and aqueous extracts were screened for larvicidal activity by exposing the A.aegypti and A.albopictus 3rd instar larvae(15 larvae per trial,triplicates)for 48 h,counting the mortalities every 24 h.Additionally,phytochemical screening for flavonoids,tannins,alkaloids,anthraquinones,anthrones,coumarins,indoles and steroids were performed on active extracts using spray tests.Results:Against A.aegypti,the three most active extracts were C.frutescens ethanolic(100%after 24 and 48 h),J.curcas ethanolic(84.44%after 24 h and 88.89%after 48 h)and M.koenigii ethanolic(53.33%after 24 h and 71.11%after 48 h).On the other hand,against A.albopictus,the three most active extracts were C.frutescens ethanolic(93.33%after 24 h and 100%after 48 h),J.curcas ethanolic(77.78%after 24 h and 82.22%after 48 h)and E.globulus ethanolic(64.44%after 24 h and 73.33%after 48 h).Phytochemical screening was also performed on the active extracts,revealing alkaloids,tannins,indoles and steroids.Conclusios:The results demonstrate the larvicidal activities of ethanolic extracts of Cymbopogon citratus,Euphorbia hirta,Ixora coccinea,Gliricidia sepium,M.koenigii,E.globulus,J.curcas and C.frutescens against A.aegypti and A.albopictus 3rd instar larvae.These could be used as potential larvicidal agents for the control of these mosquitoes.
