131 research outputs found
Atomically dispersed Ni in cadmium-zinc sulfide quantum dots for high-performance visible-light photocatalytic hydrogen production.
Catalysts with a single atom site allow highly tuning of the activity, stability, and reactivity of heterogeneous catalysts. Therefore, atomistic understanding of the pertinent mechanism is essential to simultaneously boost the intrinsic activity, site density, electron transport, and stability. Here, we report that atomically dispersed nickel (Ni) in zincblende cadmium-zinc sulfide quantum dots (ZCS QDs) delivers an efficient and durable photocatalytic performance for water splitting under sunlight. The finely tuned Ni atoms dispersed in ZCS QDs exhibit an ultrahigh photocatalytic H2 production activity of 18.87 mmol hour-1 g-1. It could be ascribed to the favorable surface engineering to achieve highly active sites of monovalent Ni(I) and the surface heterojunctions to reinforce the carrier separation owing to the suitable energy band structures, built-in electric field, and optimized surface H2 adsorption thermodynamics. This work demonstrates a synergistic regulation of the physicochemical properties of QDs for high-efficiency photocatalytic H2 production
Intravoxel incoherent motion diffusion-weighted imaging in pediatric abdominal tumor
Electronic Poster Session: Body - Whole Body DWILittle was known about the perfusion-related diffusion and true diffusion in pediatric abdominal tumor. This study aims to investigate the D, D* and f in pediatric abdominal tumors by using IVIM DW-MRI. Our results showed that there were no difference in ADC, D, D* and f of neuroblastoma and Wilms¡¯ tumor.Perfusion-related diffusion was observed in malignant and benign tumors, however there was a low D in malignant tumor compared to benign tumor. (Abstract by ISMRM)link_to_OA_fulltex
Intravoxel incoherent motion diffusion-weighted imaging in liver fibrosis of rat with bile duct ligation
Electronic Poster Session: Body - Hepatobiliary MRIThis study aims to investigate the alteration of D, D* and perfusion faction (f) in the rat liver fibrosis with biliary duct ligation by using IVIM DW-MRI. We observed a decreasing trend of D, f and ADC of the livers from D0 to D3, D7. And the differences in D, f and ADC approached statistical significance on D7 compared to D0. There was no difference in D* of the livers from D0 to D3, D7. The reduction of true diffusion and perfusion faction would be attributed to alteration of hepatic microcirculation, portal inflammation at the early stage of liver fibrosis. (Abstract by ISMRM)link_to_OA_fulltex
In vivo diffusion assessment of intramyocellular lipid droplet size changes associated with high-fat diet induced obesity and streptozotocin induced diabetes
Scientific Session - Muscle: Physiology & FunctionISMRM Merit Award: Magna cum LaudeIntramyocellular lipid (IMCL) serves as the principal reservoir for storing cellular energy in muscles. Mounting evidence indicates that elevated IMCL in skeletal muscle is closely associated with insulin resistance and type 2 diabetes. Our experimental results demonstrated that in vivo IMCL ADC can differentiate high fat diet induced obesity and STZ induced diabetes. In diabetic model, IMCL level increased but exhibited more restricted diffusion. In obesity model, the IMCL level increased but the droplet size didn't change. Diffusion measurements were largely in agreement with our histological observation. Such an MR approach may provide a new dimension in the study of intracellular lipogenesis and lipolysis, and lead to improved understanding and diagnosis in treatment and management of several prevalent metabolic disorders such as obesity and diabetes in both basic and clinical sciences. (Abstract by ISMRM)link_to_OA_fulltex
Changes in intrarenal oxygenation as evaluated by BOLD MRI in a rat biliary obstruction model
Scientific Session - Renal MRIBlood oxygenation level-dependent (BOLD) MRI was shown to allow non-invasive observation of renal oxygenation. Experimental bile duct ligation has been widely used as an animal model to evaluate the renal molecular changes. This study aims to investigate the alteration of R2* in the kidney of rat induced by biliary duct ligation. We observed that the medullary R2* in model group is higher than that in controls, but the difference in cortical R2* was not significant between two groups. Our results implicated that acute biliary obstruction induced by bile duct ligation caused an alteration of renal medullar oxygenation. (Abstract by ISMRM)link_to_OA_fulltex
A study of the influence of free convection on coagulation process
It was assumed [1, 2] that gravity affects the coagulation process in two ways: free convection, which is hard to be avoided on the ground and sedimentation, which can be greatly reduced by the density-matching method. We present a ground-based experiment set-up to study the influence of convection on the perikinetic coagulation for aqueous polystyrene (PS) dispersions. The turbidity measurement was used to evaluate the relative coagulation rate and convection-driven flows in the solution were checked with a visual-magnification system. The pattern of flow field temperature profile in the sample cell is given. Our experiments show that there was no noticeable difference of coagulation rate observed no matter whether convection flows exist (with the flow speed up to 180 mu m/s) or not
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