A comparative study of hydrothermal aging effect on cerium and lanthanum doped Cu/SSZ-13 catalysts for NH_(3)-SCR

Ce-or La-doped Cu/SSZ-13 catalysts were prepared by a hydrothermal method and Cu,Ce or La ions were incorporated through stepwise ion exchange,The catalyst activity was measured for the ammonia selective catalytic reduction reaction.The structure and composition of catalyst were characterized by using X-ray diffraction,scanning electron microscopy,inductively coupled plasma mass spectrometry solid-state NMR,NH_(3)-TPD techniques,and the active components were examined by XPS and XANES.The results indicate that the Ce and La doping can both completely preserve the SCR activity of Cu/SSZ-13 above 300℃,but there is also a decrease of activity below 200℃.On the other hand,Ce doping is beneficial to the formation of framework aluminum,stabilizes molecular sieve framework and Cu active sites of Cu/SSZ-13,thereby improves the catalyst hydrothermal stability.But La doping will decrease the amount of framework aluminum and Cu active sites of Cu/SSZ-13 after hydrothermally aging,even destroy zeolite CHA structure.This is quite harmful to the catalyst hydrothermal stability.

Dual regulation of osteoclastogenesis and osteogenesis for osteoporosis therapy by iron oxide hydroxyapatite core/shell nanocomposites

Osteoporosis is a skeletal disorder resulted in significant structural and functional changes,arousing a wide concern for the high prevalence and cost.Imbalance between osteoclastogenesis and osteogenesis have been verified as a main pathology etiology and considered an efficient therapy target in both clinical and pre-clinical studies.In recent years,inorganic nanomaterials have shown provable activities on osteoclastogenesis inhibition and osteogenesis promotion,respectively.Hence,in this study,a class of hydroxyapatite coated superparamagnetic iron oxide nanoparticles(SPIO@HA)were developed with a coreshell structure for targeting both osteoclastogenesis and osteogenesis.The optimal ratio of SPIO@15HA(Fe/Ca¼1:15,mol/mol)was screened to obtain dual function for inducing both bone formation and preventing bone resorption.The obtained nanocomposites significantly prevented the bone loss of ovariectomized(OVX)mice and increased bone mineral density(BMD)by 9.4%,exhibiting high bone accumulation in magnetic resonance imaging evaluation and reasonable biosafety profile.The mechanism study revealed that SPIO@15HA can suppress bone marrow monocyte derived osteoclast differentiation through TRAF6p62CYLD signaling complex regulation.Meanwhile,it could activate MSC osteogenic differentiation by TGF-b,PI3K-AKT and calcium signaling pathway regulation.Moreover,incubation of SPIO@15HA with MSC resulted in several cytokines overexpression such as osteoprotegerin(OPG),CSF2,CCL2 etc.,which are responsible for maintaining the bone remodeling balance.The dual function of as-prepared SPIO@15HA may find a new way for designing of inorganic components containing core/shell nanomaterials for osteoporosis treatment.

Impacts of reducing air pollutants and CO_(2) emissions in urban road transport through 2035 in Chongqing, China

The road transport sector in megacities is confronted with pressing local air pollution and carbon dioxide(CO_(2))control issues.To determine effective policy instruments for saving energy and the co-control of air pollutants and CO_(2),several mainstream measures were examined and compared in Chongqing's road transport sector from 2017 to 2035.An integration assessment framework was developed by combining the Long-range Energy Alternatives Planning(LEAP)system and a set of quantitative methods for evaluating the co-benefits of emission reductions(including the air pollutant equivalent(APeq),cocontrol coordinate system,and pollutant reduction cross-elasticity(Elsa/b)).Results showed that the shifting transportation modes scenario presented the most significant potential for energy-saving and emission reductions,reducing energy use by 30.9%and air pollutants and CO_(2) emissions by approximately 27e32%compared with the business as usual(BAU)scenario in 2035.The improving energy efficiency scenario also provided significant co-benefits for reducing air pollutants and CO_(2) emissions.Nevertheless,the promoting alternative fuel scenario may increase fine particulate matter(PM2.5)emissions by 2.2%compared to BAU in 2035 under the cleanness of regional electricity in 2017.Our findings suggest that the shifting transportation modes were effective measures to reduce air pollutants and CO_(2) in the short term synergistically,and highlighted the importance of cleaner electricity generation to develop electric vehicles in the medium and long term.

Surface carboxylation of iron oxide nanoparticles brings reduced macrophage inflammatory response through inhibiting macrophage autophagy

Macrophage autophagy is a common biological response triggered by nanomaterials,which is closely related to the regulation of inflammation.Superparamagnetic iron oxide(SPIO)nanoparticles have been used for study of autophagy response due to their broad biomedical applications.However,few reports have focused on how to regulate the macrophage autophagy response induced by SPIO nanoparticles.In this study,SPIO nanoparticles grafted with carboxyl groups were synthesized and for the comparison of macrophage autophagy with unmodified nanoparticles.The study on the correlation between autophagy and inflammation induced by the two kinds of SPIO nanoparticles was also included,and the one that grafted with carboxyl groups shows a reduction of autophagy and thereby caused a milder inflammatory response.We proposed that the increased amount of albumin adsorption on the surface of carboxylated SPIO nanoparticles,a protein previously proven to attenuate autophagy,can be considered an important reason for reducing autophagy and inflammation.In general,the carboxyl modification of SPIO nanoparticles has been demonstrated to reduce inflammation by inhibiting macrophage autophagy,which may provide some insights for the design of nanomaterials in the future.