Objective:In order that the adhesive character could be improved to modify the octyl-α-cyanoacrylate(OCA) medical adhesive.Methods:Suitable modifiers involving polycaprolactone(PCL),dibutyl phthalate (DBP),dioctyl ph...Objective:In order that the adhesive character could be improved to modify the octyl-α-cyanoacrylate(OCA) medical adhesive.Methods:Suitable modifiers involving polycaprolactone(PCL),dibutyl phthalate (DBP),dioctyl phthalate(DOP) and poly octyl methacrylat(POMA) have been chosen to modify the OCA adhesive,then tensile shear strength and adhesive strength are tested to evaluate the bond character of adhesives.Results:The PCL group's tensile shear strength and adhesive strength in normal temperature are descended while the other groups'are all enhanced.Conclusion:The modification of properties of the other groups is effectively promoted in the aspect of the bond character,except the PCL group treated in normal temperature and the PCL modified group treated by rectification get a best improvement in the agglutinate intention, while the stability is expected to be improved.展开更多
Ir-Ni-Ta metallic glasses(MGs)exhibit an array of superior high-temperature properties,making them attractive for applications at high temperatures or in harsh environments.However,Ir-Ni-Ta bulk MGs are quite brittle ...Ir-Ni-Ta metallic glasses(MGs)exhibit an array of superior high-temperature properties,making them attractive for applications at high temperatures or in harsh environments.However,Ir-Ni-Ta bulk MGs are quite brittle and often fracture catastrophically even before plastic yielding,significantly undercutting their high-strength advantage.Here,we show that the Ir-Ni-Ta MGs are not intrinsically brittle,but rather malleable when the feature size is reduced to micro/nano-scales.All tested Ir-Ni-Ta MG micropillars with a diameter ranging from~500 nm to~5μm display a large plastic strain above 25%(the maximum up to 35%),together with a yield strength up to 7 GPa,well exceeding the strength recorded in most metallic materials.The intrinsic shear stability of Ir-Ni-Ta MGs,as characterized by the normalized shear displacement during a shear event,is much larger than those malleable Zr-and Cu-based MGs.Our results suggest that Ir-Ni-Ta MGs are excellent candidates for micro/nanoscale structural applications used at high-temperature or extreme conditions.展开更多
Objective： To investigate the material properties of normal and degenerated intervertebral discs （IVDs） and examine the effect of degenerative changes on IVD pathology. Methods： A computer-based online search was...Objective： To investigate the material properties of normal and degenerated intervertebral discs （IVDs） and examine the effect of degenerative changes on IVD pathology. Methods： A computer-based online search was undertaken to identify English articles about material properties of IVDs published from January 1950 to 2011 in PubMed database. The retrieved keywords included material properties, intervertebral disc and degeneration. Based on the principles of reliability, advancement and efficiency, the obtained data were primarily examined, and the original source was retrieved to read the full-text. Repetitive articles were excluded. The data of material properties of normal and degenerated IVDs were summarized and analyzed by meta-analysis. Results： The data of Young＇s modulus, Poisson＇s ratio, shear modulus, hydraulic permeability and intradiscal pres- sure of normal and degenerated 1VDs were obtained. Com- pared with normal IVDs, the Young＇s modulus and shear modulus of annulus fibrosus and nucleus pulposus werehigher in degenerated IVDs, the Poisson＇s ratio was lower while the hydraulic permeability and intradiscal pressure were higher. Besides, the degeneration-related alterations in IVDs had an influence both on itself and other spinal structures, leading to diseases such as bulging disc, discogenic pain and spinal stenosis. Meanwhile, the heavy mechanical loading and injury indicated important pathways to IVD degeneration. Conclusions： To a certain extent, the degenerative changes of IVD influence its material properties. And the degeneration-related alterations of composition can cause structural failure oflVDs, leading to injuries and diseases.展开更多
文摘Objective:In order that the adhesive character could be improved to modify the octyl-α-cyanoacrylate(OCA) medical adhesive.Methods:Suitable modifiers involving polycaprolactone(PCL),dibutyl phthalate (DBP),dioctyl phthalate(DOP) and poly octyl methacrylat(POMA) have been chosen to modify the OCA adhesive,then tensile shear strength and adhesive strength are tested to evaluate the bond character of adhesives.Results:The PCL group's tensile shear strength and adhesive strength in normal temperature are descended while the other groups'are all enhanced.Conclusion:The modification of properties of the other groups is effectively promoted in the aspect of the bond character,except the PCL group treated in normal temperature and the PCL modified group treated by rectification get a best improvement in the agglutinate intention, while the stability is expected to be improved.
基金supported by the National Key Research and Development Plan(2018YFA0703603)Guangdong Major Project of Basic and Applied Basic Research,China(2019B030302010)+1 种基金the National Natural Science Foundation of China(51822107,11790291 and 61888102)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB30000000)。
文摘Ir-Ni-Ta metallic glasses(MGs)exhibit an array of superior high-temperature properties,making them attractive for applications at high temperatures or in harsh environments.However,Ir-Ni-Ta bulk MGs are quite brittle and often fracture catastrophically even before plastic yielding,significantly undercutting their high-strength advantage.Here,we show that the Ir-Ni-Ta MGs are not intrinsically brittle,but rather malleable when the feature size is reduced to micro/nano-scales.All tested Ir-Ni-Ta MG micropillars with a diameter ranging from~500 nm to~5μm display a large plastic strain above 25%(the maximum up to 35%),together with a yield strength up to 7 GPa,well exceeding the strength recorded in most metallic materials.The intrinsic shear stability of Ir-Ni-Ta MGs,as characterized by the normalized shear displacement during a shear event,is much larger than those malleable Zr-and Cu-based MGs.Our results suggest that Ir-Ni-Ta MGs are excellent candidates for micro/nanoscale structural applications used at high-temperature or extreme conditions.
基金This work was supported by grants from the National Natural Science Foundation of China （No. 30928005）, the Chongqing Natural Science Foundation of China （No. CSTC2009BB5013）, the Third Military Medical University Research Foundation of China （No. 2009XHG16）, and the Graduate Student＇s Scientific Research Innovation Foundation of Chinese Government （No. CDJXS11121145）.
文摘Objective： To investigate the material properties of normal and degenerated intervertebral discs （IVDs） and examine the effect of degenerative changes on IVD pathology. Methods： A computer-based online search was undertaken to identify English articles about material properties of IVDs published from January 1950 to 2011 in PubMed database. The retrieved keywords included material properties, intervertebral disc and degeneration. Based on the principles of reliability, advancement and efficiency, the obtained data were primarily examined, and the original source was retrieved to read the full-text. Repetitive articles were excluded. The data of material properties of normal and degenerated IVDs were summarized and analyzed by meta-analysis. Results： The data of Young＇s modulus, Poisson＇s ratio, shear modulus, hydraulic permeability and intradiscal pres- sure of normal and degenerated 1VDs were obtained. Com- pared with normal IVDs, the Young＇s modulus and shear modulus of annulus fibrosus and nucleus pulposus werehigher in degenerated IVDs, the Poisson＇s ratio was lower while the hydraulic permeability and intradiscal pressure were higher. Besides, the degeneration-related alterations in IVDs had an influence both on itself and other spinal structures, leading to diseases such as bulging disc, discogenic pain and spinal stenosis. Meanwhile, the heavy mechanical loading and injury indicated important pathways to IVD degeneration. Conclusions： To a certain extent, the degenerative changes of IVD influence its material properties. And the degeneration-related alterations of composition can cause structural failure oflVDs, leading to injuries and diseases.
