Extremely small-sized iron oxide nanoparticles(ESIONPs)with sizes less than 5 nm have shown great promise as T_(1)contrast agents for magnetic resonance imaging(MRI).However,their facile and scalable production with s...Extremely small-sized iron oxide nanoparticles(ESIONPs)with sizes less than 5 nm have shown great promise as T_(1)contrast agents for magnetic resonance imaging(MRI).However,their facile and scalable production with simultaneously endowed biocompatible surface chemistry remains difficult to be realized.In this study,by using the coprecipitation method implemented in a specially designed gas/liquid mixed phase fluidic reactor,polyglucose sorbitol carboxymethyether(PSC)coated ESIONPs were continuously synthesized with controllable particle sizes ranging from 1.8 to 4 nm.Among the differently sized ESIONPs,the 3.7-nm ESIONPs exhibit the best performance as T_(1)MRI contrast agent,featuring a high r_(1) value of 4.11(mmol L^(−1))^(−1)s^(−1)and low r_(2)/r_(1) ratio of 7.90 under a clinical 3 T MR scanning,as well as the excellent T_(1)MRI contrast effect in not only water but also the cellular environment and blood vessel.Furthermore,the ESIONPs possess long-term stability and good dispersity in aqueous dispersions,making them ideal candidates as safe and effective T_(1)-weighted MRI contrast agent for real clinical use.展开更多
Experimentalists, numerical modellers and reactor modellers need to work together, not only just for validation of numerical codes, but also to shed fundamental light on each other＇s problems and underlying assumptio...Experimentalists, numerical modellers and reactor modellers need to work together, not only just for validation of numerical codes, but also to shed fundamental light on each other＇s problems and underlying assumptions. Several examples are given, Experimental gas axial dispersion data provide a means of choosing the most appropriate boundary condition （no slip, partial slip or full slip） for particles at the wall of fluidized beds. CFD simulations help to identify how close ＂two-dimensional＂ experimental columns are to being truly two-dimensional and to representing three-dimensional columns. CFD also can be used to provide a more rational means of establishing assumptions needed in the modelling of two-phase fluidized bed reactors, for example how to deal with cases where there is a change in molar flow （and hence volumetric flow） as a result of chemical reactions.展开更多
基金supported by the grant received from the National Key Research and Development Program of China(2017YFA0104302)the Key Project of the National Natural Science Foundation of China(NSFC,51832001)+1 种基金the National Natural Science Innovative Research Group Project(61821002)the Project of the National Natural Science Foundation of China(31800843)。
文摘Extremely small-sized iron oxide nanoparticles(ESIONPs)with sizes less than 5 nm have shown great promise as T_(1)contrast agents for magnetic resonance imaging(MRI).However,their facile and scalable production with simultaneously endowed biocompatible surface chemistry remains difficult to be realized.In this study,by using the coprecipitation method implemented in a specially designed gas/liquid mixed phase fluidic reactor,polyglucose sorbitol carboxymethyether(PSC)coated ESIONPs were continuously synthesized with controllable particle sizes ranging from 1.8 to 4 nm.Among the differently sized ESIONPs,the 3.7-nm ESIONPs exhibit the best performance as T_(1)MRI contrast agent,featuring a high r_(1) value of 4.11(mmol L^(−1))^(−1)s^(−1)and low r_(2)/r_(1) ratio of 7.90 under a clinical 3 T MR scanning,as well as the excellent T_(1)MRI contrast effect in not only water but also the cellular environment and blood vessel.Furthermore,the ESIONPs possess long-term stability and good dispersity in aqueous dispersions,making them ideal candidates as safe and effective T_(1)-weighted MRI contrast agent for real clinical use.
文摘Experimentalists, numerical modellers and reactor modellers need to work together, not only just for validation of numerical codes, but also to shed fundamental light on each other＇s problems and underlying assumptions. Several examples are given, Experimental gas axial dispersion data provide a means of choosing the most appropriate boundary condition （no slip, partial slip or full slip） for particles at the wall of fluidized beds. CFD simulations help to identify how close ＂two-dimensional＂ experimental columns are to being truly two-dimensional and to representing three-dimensional columns. CFD also can be used to provide a more rational means of establishing assumptions needed in the modelling of two-phase fluidized bed reactors, for example how to deal with cases where there is a change in molar flow （and hence volumetric flow） as a result of chemical reactions.
