The utilization of biodegradable magnesium(Mg)-based implants for restoration of bone function following trauma represents a transformative approach in orthopaedic application.One such alloy,magnesium-10 weight percen...The utilization of biodegradable magnesium(Mg)-based implants for restoration of bone function following trauma represents a transformative approach in orthopaedic application.One such alloy,magnesium-10 weight percent gadolinium(Mg-10Gd),has been specifically developed to address the rapid degradation of Mg while enhancing its mechanical properties to promote bone healing.Previous studies have demonstrated that Mg-10Gd exhibits favorable osseointegration;however,it exhibits distinct ultrastructural adaptation in comparison to conventional implants like titanium(Ti).A crucial aspect that remains unexplored is the impact of Mg-10Gd degradation on the bone microarchitecture.To address this,we employed hierarchical three-dimensional imaging using synchrotron radiation in conjunction with image-based finite element modelling.By using the methods outlined,the vascular porosity,lacunar porosity and the lacunar-canaliculi network(LCN)morphology of bone around Mg-10Gd in comparison to Ti in a rat model from 4 weeks to 20 weeks post-implantation was investigated.Our investigation revealed that within our observation period,the degradation of Mg-10Gd implants was associated with significantly lower(p<0.05)lacunar density in the surrounding bone,compared to Ti.Remarkably,the LCN morphology and the fluid flow analysis did not significantly differ for both implant types.In summary,a more pronounced lower lacunae distribution rather than their morphological changes was detected in the surrounding bone upon the degradation of Mg-10Gd implants.This implies potential disparities in bone remodelling rates when compared to Ti implants.Our findings shed light on the intricate relationship between Mg-10Gd degradation and bone microarchitecture,contributing to a deeper understanding of the implications for successful osseointegration.展开更多
Large-scale-applicable thermoelectric materials should be both self-sustaining,in order to survive longterm duty cycles,and nonpolluting.Among all classes of known thermoelectric materials,these criteria reduce the av...Large-scale-applicable thermoelectric materials should be both self-sustaining,in order to survive longterm duty cycles,and nonpolluting.Among all classes of known thermoelectric materials,these criteria reduce the available candidate pool,leaving silicon as one of the remaining options.Here we first review the thermoelectric properties of various silicon-related materials with respect to their morphologies and microstructures.We then report the thermoelectric properties of silicon sawing wastes recycled from silicon wafer manufacturing.We obtain a high power factor of~32 mWcm1 K2 at 1273 K with 6%phosphorus substitution in the Si crystal,a value comparable to that of phosphorus-doped silicongermanium alloys.Our work suggests the large-scale thermoelectric applicability of recycled silicon that would otherwise contribute to the millions of tons of industrial waste produced by the semiconductor industry.展开更多
文摘The utilization of biodegradable magnesium(Mg)-based implants for restoration of bone function following trauma represents a transformative approach in orthopaedic application.One such alloy,magnesium-10 weight percent gadolinium(Mg-10Gd),has been specifically developed to address the rapid degradation of Mg while enhancing its mechanical properties to promote bone healing.Previous studies have demonstrated that Mg-10Gd exhibits favorable osseointegration;however,it exhibits distinct ultrastructural adaptation in comparison to conventional implants like titanium(Ti).A crucial aspect that remains unexplored is the impact of Mg-10Gd degradation on the bone microarchitecture.To address this,we employed hierarchical three-dimensional imaging using synchrotron radiation in conjunction with image-based finite element modelling.By using the methods outlined,the vascular porosity,lacunar porosity and the lacunar-canaliculi network(LCN)morphology of bone around Mg-10Gd in comparison to Ti in a rat model from 4 weeks to 20 weeks post-implantation was investigated.Our investigation revealed that within our observation period,the degradation of Mg-10Gd implants was associated with significantly lower(p<0.05)lacunar density in the surrounding bone,compared to Ti.Remarkably,the LCN morphology and the fluid flow analysis did not significantly differ for both implant types.In summary,a more pronounced lower lacunae distribution rather than their morphological changes was detected in the surrounding bone upon the degradation of Mg-10Gd implants.This implies potential disparities in bone remodelling rates when compared to Ti implants.Our findings shed light on the intricate relationship between Mg-10Gd degradation and bone microarchitecture,contributing to a deeper understanding of the implications for successful osseointegration.
基金The work performed at the University of Houston is funded by the U.S.Department of Energy under Grant DE-SC0010831.
文摘Large-scale-applicable thermoelectric materials should be both self-sustaining,in order to survive longterm duty cycles,and nonpolluting.Among all classes of known thermoelectric materials,these criteria reduce the available candidate pool,leaving silicon as one of the remaining options.Here we first review the thermoelectric properties of various silicon-related materials with respect to their morphologies and microstructures.We then report the thermoelectric properties of silicon sawing wastes recycled from silicon wafer manufacturing.We obtain a high power factor of~32 mWcm1 K2 at 1273 K with 6%phosphorus substitution in the Si crystal,a value comparable to that of phosphorus-doped silicongermanium alloys.Our work suggests the large-scale thermoelectric applicability of recycled silicon that would otherwise contribute to the millions of tons of industrial waste produced by the semiconductor industry.
