Over the last few years,there is huge scientific attention towards the research related to Extracellular Vesicles(EVs),because of their unique property of inter cellular communications and effective biological signifi...Over the last few years,there is huge scientific attention towards the research related to Extracellular Vesicles(EVs),because of their unique property of inter cellular communications and effective biological significance in diagnosis and therapy[1].Extracellular Vesicles are lipid bilayer membrane bound biological entity,which contains different bioactive compounds(cargoes)such as microRNAs(miRNAs),mRNAs,proteins,and lipids.Based on their origin and size,EVs have been categorized into three different types(a)Exosomes(40 nm-150 nm)are smallest EVs,which are synthesized by endocytic pathways in the cells and secreted in extracellular space through exocytosis process,(b)Microvesicles are secreted from direct budding off plasma membranes and their size varying from 50 nm to 1000 nm and,(c)Apoptotic bodies are formed during apoptotic cell death process and respectively larger in size>1000 nm[1-3].EVs have been identified using different markers,that includes tetraspanins proteins(CD9,CD63,CD81,and CD83),endosomal sorting complexes required for transport(TSG101,Alix),heat shock proteins(Hsp60,Hsp70,Hsp90),and Rab proteins(RAB27a/b)[1].展开更多
Metal nanoparticle （NP） co-catalysts on metal oxide semiconductor supports are attracting attention as photocatalysts for a variety of chemical reactions. Related efforts seek to make and use Pt-free catalysts. In t...Metal nanoparticle （NP） co-catalysts on metal oxide semiconductor supports are attracting attention as photocatalysts for a variety of chemical reactions. Related efforts seek to make and use Pt-free catalysts. In this regard, we report here enhanced CH4 formation rates of 25 and 60 μmol·g^-1·h^-1 by photocatalytic CO2 reduction using hitherto unused ZnPd NPs as well as Au and Ru NPs. The NPs are formed by colloidal synthesis and grafted onto short n-type anatase TiO2 nanotube arrays （TNAs）, grown anodically on transparent glass substrates. The interfacial electric fields in the NP-grafted TiO2 nanotubes were probed by ultraviolet photoelectron spectroscopy （UPS）. Au NP-grafted TiO2 nanotubes （Au-TNAs） showed no band bending, but a depletion region was detected in Ru NP-grafted TNAs （Ru-TNAs） and an accumulation layer was observed in ZnPd NP-grafted TNAs （ZnPd-TNAs）. Temperature programmed desorption （TPD） experiments showed significantly greater CO2 adsorption on NP-grafted TNAs. TNAs with grafted NPs exhibit broader and more intense UV-visible absorption bands than bare TNAs. We found that CO2 photoreduction by nanoparticle-grafted TNAs was driven not only by ultraviolet photons with energies greater than the TiO2 band gap, but also by blue photons close to and below the anatase band edge. The enhanced rate of CO2 reduction is attributed to superior use of blue photons in the solar spectrum, excellent reactant adsorption, efficient charge transfer to adsorbates, and low recombination losses.展开更多
文摘Over the last few years,there is huge scientific attention towards the research related to Extracellular Vesicles(EVs),because of their unique property of inter cellular communications and effective biological significance in diagnosis and therapy[1].Extracellular Vesicles are lipid bilayer membrane bound biological entity,which contains different bioactive compounds(cargoes)such as microRNAs(miRNAs),mRNAs,proteins,and lipids.Based on their origin and size,EVs have been categorized into three different types(a)Exosomes(40 nm-150 nm)are smallest EVs,which are synthesized by endocytic pathways in the cells and secreted in extracellular space through exocytosis process,(b)Microvesicles are secreted from direct budding off plasma membranes and their size varying from 50 nm to 1000 nm and,(c)Apoptotic bodies are formed during apoptotic cell death process and respectively larger in size>1000 nm[1-3].EVs have been identified using different markers,that includes tetraspanins proteins(CD9,CD63,CD81,and CD83),endosomal sorting complexes required for transport(TSG101,Alix),heat shock proteins(Hsp60,Hsp70,Hsp90),and Rab proteins(RAB27a/b)[1].
文摘Metal nanoparticle （NP） co-catalysts on metal oxide semiconductor supports are attracting attention as photocatalysts for a variety of chemical reactions. Related efforts seek to make and use Pt-free catalysts. In this regard, we report here enhanced CH4 formation rates of 25 and 60 μmol·g^-1·h^-1 by photocatalytic CO2 reduction using hitherto unused ZnPd NPs as well as Au and Ru NPs. The NPs are formed by colloidal synthesis and grafted onto short n-type anatase TiO2 nanotube arrays （TNAs）, grown anodically on transparent glass substrates. The interfacial electric fields in the NP-grafted TiO2 nanotubes were probed by ultraviolet photoelectron spectroscopy （UPS）. Au NP-grafted TiO2 nanotubes （Au-TNAs） showed no band bending, but a depletion region was detected in Ru NP-grafted TNAs （Ru-TNAs） and an accumulation layer was observed in ZnPd NP-grafted TNAs （ZnPd-TNAs）. Temperature programmed desorption （TPD） experiments showed significantly greater CO2 adsorption on NP-grafted TNAs. TNAs with grafted NPs exhibit broader and more intense UV-visible absorption bands than bare TNAs. We found that CO2 photoreduction by nanoparticle-grafted TNAs was driven not only by ultraviolet photons with energies greater than the TiO2 band gap, but also by blue photons close to and below the anatase band edge. The enhanced rate of CO2 reduction is attributed to superior use of blue photons in the solar spectrum, excellent reactant adsorption, efficient charge transfer to adsorbates, and low recombination losses.
