The nonequilibrium composition and its formation process are critical aspects of nanoparticle production technology.Understanding the dynamics of nanoparticle formation under nonequilibrium conditions is essential.In ...The nonequilibrium composition and its formation process are critical aspects of nanoparticle production technology.Understanding the dynamics of nanoparticle formation under nonequilibrium conditions is essential.In this study,Crdoped CeO_(2) nanoparticles are synthesized via continuous-flow hydrothermal synthesis at various temperatures(300,350,400℃)with reaction times precisely controlled on the order of seconds.At the initial stage of particle formation,Cr-rich CeO_(2) particles form due to a low surface energy.Over time,the Cr content decreases as the particles relax toward the equilibrium structure.This process yields an unusual nonequilibrium composition through rapid heating and short residence times.Similar nonequilibrium compositions are also observed for other dopants,such as Fe and Eu.Continuous-flow hydrothermal synthesis thus presents an efficient method for fabricating nanomaterials with unique compositions that are unattainable using conventional batch methods.展开更多
Genetically engineered bacteria have aroused attention as micro-nano drug delivery systems in situ.However,conventional designs of engineered bacteria usually function constantly or autonomously,which might be non-spe...Genetically engineered bacteria have aroused attention as micro-nano drug delivery systems in situ.However,conventional designs of engineered bacteria usually function constantly or autonomously,which might be non-specific or imprecise.Therefore,designing and optimizing in situ control strategy are important methodological progress for therapeutic researches of intestinal engineered bacteria.Here,a micro-nano optogenetic system based on probiotic was developed combining microelectronics,nanotechnology,and synthetic biology to achieve in situ controllable drug delivery.Firstly,optogenetic engineered Lactococcus lactis was orally administrated in the intestinal tract.A wearable optical device was designed to control optical signals remotely.Then,L.lactis could be customized to secrete peptides according to optical signals.As an example,optogenetic L.lactis system can be constructed to secrete glucagon-like peptide-1(GLP-1)under the control of the wearable optical device to regulate metabolism.To improve the half-life of GLP-1 in vivo,Fc-domain fused GLP-1 was optimally used.Using this strategy,blood glucose,weight,and other features were well controlled in rats and mice models.Furthermore,upconversion microcapsules were introduced to increase the excitation wavelength of the optogenetic system for better penetrability.This strategy has biomedical potential to expand the toolbox for intestinal engineered bacteria.展开更多
A novel spray-assisted carbonation microreaction method for the synthesis of mesoporous silica microspheres is reported.The synthetic process comprises the preparation of a silica sol via a carbonation reaction,rapid ...A novel spray-assisted carbonation microreaction method for the synthesis of mesoporous silica microspheres is reported.The synthetic process comprises the preparation of a silica sol via a carbonation reaction,rapid gelation at high temperature,and subsequent rapid solvent evaporation by spray drying.The carbonation microreaction was conducted in a membrane dispersion microreactor,in the presence of sodium silicate and carbon dioxide reactants.The as-synthesized silica microspheres exhibit a uniform mesostructure,excellent dispersity,and a narrow particle size distribution,with average diameters of 1-2 μm,Brunauer-Emmett-Teller surface areas of 300-1149m2/g,and total pore volumes of 0.21-1.82 cm3/g.Relatively low concentrations of the silicate species and well-controlled silica condensation rates are responsible for the formation of the observed spherical morphology.The synthetic process is of significant practical importance as a result of using low-cost raw materials,and because of the excellent controllability and process stability displayed.Furthermore,this rapid and flexible method may be extended to the synthesis of various silica materials and their composites.展开更多
基金support from the Japan Science and Technology Agency(JST)[MIRAI,Grant No.JPMJMI17E4,and CREST,Grant No.JPMJCR16P3]the New Energy and Industrial Technology Development Organization of Japan(NEDO)+1 种基金JSPS KAKENHI(Grant Numbers JP16H06367,JP20K20548,and JP21H05010)the Materials Processing Science Project(Materealize,Grant No.JPMXP0219192801).
文摘The nonequilibrium composition and its formation process are critical aspects of nanoparticle production technology.Understanding the dynamics of nanoparticle formation under nonequilibrium conditions is essential.In this study,Crdoped CeO_(2) nanoparticles are synthesized via continuous-flow hydrothermal synthesis at various temperatures(300,350,400℃)with reaction times precisely controlled on the order of seconds.At the initial stage of particle formation,Cr-rich CeO_(2) particles form due to a low surface energy.Over time,the Cr content decreases as the particles relax toward the equilibrium structure.This process yields an unusual nonequilibrium composition through rapid heating and short residence times.Similar nonequilibrium compositions are also observed for other dopants,such as Fe and Eu.Continuous-flow hydrothermal synthesis thus presents an efficient method for fabricating nanomaterials with unique compositions that are unattainable using conventional batch methods.
基金sponsored by the National Science Fund for Excellent Young Scholars(No.32122047)the National Key Research and Development Program of China(No.2019YFA0906500)+3 种基金the National Natural Science Foundation of China(Nos.31971300 and 51873150)the Key project of Tianjin Foundational Research(JingJinJi)Program,China(No.19JCZDJC64100)the Key Research and Development Program of Tianjin(No.19YFZCSY00190)the National Science Foundation of Tianjin(No.20YDTPJC00090).
文摘Genetically engineered bacteria have aroused attention as micro-nano drug delivery systems in situ.However,conventional designs of engineered bacteria usually function constantly or autonomously,which might be non-specific or imprecise.Therefore,designing and optimizing in situ control strategy are important methodological progress for therapeutic researches of intestinal engineered bacteria.Here,a micro-nano optogenetic system based on probiotic was developed combining microelectronics,nanotechnology,and synthetic biology to achieve in situ controllable drug delivery.Firstly,optogenetic engineered Lactococcus lactis was orally administrated in the intestinal tract.A wearable optical device was designed to control optical signals remotely.Then,L.lactis could be customized to secrete peptides according to optical signals.As an example,optogenetic L.lactis system can be constructed to secrete glucagon-like peptide-1(GLP-1)under the control of the wearable optical device to regulate metabolism.To improve the half-life of GLP-1 in vivo,Fc-domain fused GLP-1 was optimally used.Using this strategy,blood glucose,weight,and other features were well controlled in rats and mice models.Furthermore,upconversion microcapsules were introduced to increase the excitation wavelength of the optogenetic system for better penetrability.This strategy has biomedical potential to expand the toolbox for intestinal engineered bacteria.
基金We gratefully acknowledge the support from the National Nat-ural Science Foundation of China(Nos.91334201,U1463208 and 21506110).
文摘A novel spray-assisted carbonation microreaction method for the synthesis of mesoporous silica microspheres is reported.The synthetic process comprises the preparation of a silica sol via a carbonation reaction,rapid gelation at high temperature,and subsequent rapid solvent evaporation by spray drying.The carbonation microreaction was conducted in a membrane dispersion microreactor,in the presence of sodium silicate and carbon dioxide reactants.The as-synthesized silica microspheres exhibit a uniform mesostructure,excellent dispersity,and a narrow particle size distribution,with average diameters of 1-2 μm,Brunauer-Emmett-Teller surface areas of 300-1149m2/g,and total pore volumes of 0.21-1.82 cm3/g.Relatively low concentrations of the silicate species and well-controlled silica condensation rates are responsible for the formation of the observed spherical morphology.The synthetic process is of significant practical importance as a result of using low-cost raw materials,and because of the excellent controllability and process stability displayed.Furthermore,this rapid and flexible method may be extended to the synthesis of various silica materials and their composites.
