Objective： To evaluate the effects of botulinum toxin type A （BTX-A） on mandible skeletal development by inducing muscle hypofunction. Methods： Four-week-old Sprague-Dawley rats （n=60） were divided into three gr...Objective： To evaluate the effects of botulinum toxin type A （BTX-A） on mandible skeletal development by inducing muscle hypofunction. Methods： Four-week-old Sprague-Dawley rats （n=60） were divided into three groups： Group 1 animals served as controls and were injected with saline; Group 2 animals were injected unilaterally with BTX-A （the contralateral side was injected with saline）; and Group 3 animals were injected bilaterally with BTX-A. In Group 2, the saline-injected side was designated the control side （Group 2-1）, whereas the BTX-A-injected side was designated the experimental side （Group 2-2）. After four weeks, the animals were sacrificed, dry skulls were prepared, and mandibles were measured. Results： In the unilateral group, the experimental side （Group 2-2） had reduced di- mensions for all mandible measurements compared with the control side （Group 2-1）, suggesting a local effect of BTX-A on mandible growth, likely due to muscle reduction. Conclusions： Localized BTX-A injection induced a change in craniofacial growth, and the skeletal effect was unilateral despite both sides of the mandible functioning as one unit.展开更多
Tailoring nanostructures is a general approach used to obtain enhanced thermoelectric properties for halfHeusler compounds because the wide areas of grain and phase boundaries could be scattering centers that lower la...Tailoring nanostructures is a general approach used to obtain enhanced thermoelectric properties for halfHeusler compounds because the wide areas of grain and phase boundaries could be scattering centers that lower lattice thermal conductivity.However,a common fabrication method based on the sintering of crystalline precursors crushed from as-cast alloy ingots has limitations in obtaining a homogeneous microstructure without microsized impurity phases,owing to residual elemental segregation from casting.In this study,we used amorphous NbCoSn alloys as a precursor for the sintered specimen to obtain a homogeneous NbCoSn bulk specimen without microsized impurity phases and segregation,which led to the enhanced Seebeck coefficient due to the high purity of the half-Heusler phase after crystallization.Moreover,superplasticity originating from amorphous features enabled the powders to be largely deformed during the sintering process,even at a low sintering temperature(953 K).This resulted in less oxidation at both,the grain boundary and the interior,as the O diffusion pathway was blocked during the sintering process.As a result,the NbCoSn0.95Sb0.05 specimen using an amorphous precursor exhibited an enhanced zT of 0.7,due to the increase in the power factor and a decrease in lattice thermal conductivity compared to the specimen using a crystalline precursor.展开更多
基金supported by the Samsung Biomedical Research Institute Grant(No.CA53061),Korea
文摘Objective： To evaluate the effects of botulinum toxin type A （BTX-A） on mandible skeletal development by inducing muscle hypofunction. Methods： Four-week-old Sprague-Dawley rats （n=60） were divided into three groups： Group 1 animals served as controls and were injected with saline; Group 2 animals were injected unilaterally with BTX-A （the contralateral side was injected with saline）; and Group 3 animals were injected bilaterally with BTX-A. In Group 2, the saline-injected side was designated the control side （Group 2-1）, whereas the BTX-A-injected side was designated the experimental side （Group 2-2）. After four weeks, the animals were sacrificed, dry skulls were prepared, and mandibles were measured. Results： In the unilateral group, the experimental side （Group 2-2） had reduced di- mensions for all mandible measurements compared with the control side （Group 2-1）, suggesting a local effect of BTX-A on mandible growth, likely due to muscle reduction. Conclusions： Localized BTX-A injection induced a change in craniofacial growth, and the skeletal effect was unilateral despite both sides of the mandible functioning as one unit.
基金the Basic Science Research Program of the National Research Foundation of Korea(NRF)(Nos.2021R1A4A2001658 and 2021R1A6A3A03045488).
文摘Tailoring nanostructures is a general approach used to obtain enhanced thermoelectric properties for halfHeusler compounds because the wide areas of grain and phase boundaries could be scattering centers that lower lattice thermal conductivity.However,a common fabrication method based on the sintering of crystalline precursors crushed from as-cast alloy ingots has limitations in obtaining a homogeneous microstructure without microsized impurity phases,owing to residual elemental segregation from casting.In this study,we used amorphous NbCoSn alloys as a precursor for the sintered specimen to obtain a homogeneous NbCoSn bulk specimen without microsized impurity phases and segregation,which led to the enhanced Seebeck coefficient due to the high purity of the half-Heusler phase after crystallization.Moreover,superplasticity originating from amorphous features enabled the powders to be largely deformed during the sintering process,even at a low sintering temperature(953 K).This resulted in less oxidation at both,the grain boundary and the interior,as the O diffusion pathway was blocked during the sintering process.As a result,the NbCoSn0.95Sb0.05 specimen using an amorphous precursor exhibited an enhanced zT of 0.7,due to the increase in the power factor and a decrease in lattice thermal conductivity compared to the specimen using a crystalline precursor.
