In this study,a novel artificial intervertebral disc implant with modified“Bucklicrystal”structure was designed and 3D printed using thermoplastic polyurethane.The new implant has a unique auxetic structure with bui...In this study,a novel artificial intervertebral disc implant with modified“Bucklicrystal”structure was designed and 3D printed using thermoplastic polyurethane.The new implant has a unique auxetic structure with building blocks joined“face-to-face”.The accompanied negative Poisson’s ratio enables its excellent energy absorption and stability under compression.The deformation and load distribution behavior of the implant under various loading conditions(bending,torsion,extension and flexion)has been thoroughly evaluated through finite element method.Results show that,compared to natural intervertebral disc and conventional 3D implant,our new implant exhibits more effective stress transfer and attenuation under practical loading conditions.The implant’s ability to contract laterally under compression can be potentially used to alleviate the symptoms of lumbar disc herniation.Finally,the biocompatibility of the implant was assessed in vitro and its ability to restore the physiological function of the disc segment was validated in vivo using an animal model.展开更多
It is well documented that rice paddy fields act as agricultural wetlands that remove or retain nutrients;however,their associated effects on soil microbial communities are rarely reported.The present study evaluates ...It is well documented that rice paddy fields act as agricultural wetlands that remove or retain nutrients;however,their associated effects on soil microbial communities are rarely reported.The present study evaluates the impact of rice variety on nutrient removal via plant uptake,nutrient retention in the soil,and bacterial associations in rice paddy fields,using a network analysis that compares the soil bacterial communities of two rice varieties.We found that the high-straw rice variety(YD-1)allows uptake of a high amount of nitrogen(N)and phosphorus(P)from paddy rice fields via harvesting,but causes less residual total N and P to remain in the soil.However,both rice varieties(YD-1 and XS-134(Xiushui-134))had non-significant effects on the dominant bacterial taxa.The short-term response of bacterial community diversity to rice variety is found to be mainly due to less frequently recovered species.A network analysis that incorporates soil nutrients as nodes,along with bacterial taxa,found that only one node representing the total P related to the non-dominant species had an indirect association with the rice straw biomass.The observed short-term impact of the two rice varieties(XS-134 and YD-1)on soil bacterial diversity and nutrient surplus in these agricultural wetlands is limited under a high level of fertilization.展开更多
基金support from the National Natural Science Foundation of China(No.81772397,81871772,82072434)aSichuan Science and Technology Program(2021YFH0134,2020YFS0131).
文摘In this study,a novel artificial intervertebral disc implant with modified“Bucklicrystal”structure was designed and 3D printed using thermoplastic polyurethane.The new implant has a unique auxetic structure with building blocks joined“face-to-face”.The accompanied negative Poisson’s ratio enables its excellent energy absorption and stability under compression.The deformation and load distribution behavior of the implant under various loading conditions(bending,torsion,extension and flexion)has been thoroughly evaluated through finite element method.Results show that,compared to natural intervertebral disc and conventional 3D implant,our new implant exhibits more effective stress transfer and attenuation under practical loading conditions.The implant’s ability to contract laterally under compression can be potentially used to alleviate the symptoms of lumbar disc herniation.Finally,the biocompatibility of the implant was assessed in vitro and its ability to restore the physiological function of the disc segment was validated in vivo using an animal model.
基金the National Key Research and Development Program of China(2017YFD0800103)Natural Science Foundation of Zhejiang Province(LR16B070001)the National Natural Science Foundation of China(41522108).
文摘It is well documented that rice paddy fields act as agricultural wetlands that remove or retain nutrients;however,their associated effects on soil microbial communities are rarely reported.The present study evaluates the impact of rice variety on nutrient removal via plant uptake,nutrient retention in the soil,and bacterial associations in rice paddy fields,using a network analysis that compares the soil bacterial communities of two rice varieties.We found that the high-straw rice variety(YD-1)allows uptake of a high amount of nitrogen(N)and phosphorus(P)from paddy rice fields via harvesting,but causes less residual total N and P to remain in the soil.However,both rice varieties(YD-1 and XS-134(Xiushui-134))had non-significant effects on the dominant bacterial taxa.The short-term response of bacterial community diversity to rice variety is found to be mainly due to less frequently recovered species.A network analysis that incorporates soil nutrients as nodes,along with bacterial taxa,found that only one node representing the total P related to the non-dominant species had an indirect association with the rice straw biomass.The observed short-term impact of the two rice varieties(XS-134 and YD-1)on soil bacterial diversity and nutrient surplus in these agricultural wetlands is limited under a high level of fertilization.
