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3.0T MRI与高分辨力超声对颈动脉内-中膜厚度和可扩张性测量的比较 被引量:3
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作者 A.Harloff T.Zech +4 位作者 A.Frydrychowicz m.schumacher J.Schllhorn J.Hennig 刘学焕 《国际医学放射学杂志》 2009年第4期413-414,共2页
评价3.0TMRI检查对于评估32例健康志愿者及20例重度颈内动脉狭窄病人的颈总动脉(CCA)形态及功能的价值。颈总动脉管壁厚度通过多层2D T2快速自旋回波黑血技术获得,并与超声测量的中-内膜厚度(IMT)相比较。颈总动脉可扩张系数(DC... 评价3.0TMRI检查对于评估32例健康志愿者及20例重度颈内动脉狭窄病人的颈总动脉(CCA)形态及功能的价值。颈总动脉管壁厚度通过多层2D T2快速自旋回波黑血技术获得,并与超声测量的中-内膜厚度(IMT)相比较。颈总动脉可扩张系数(DC)通过血压和心电门控的3D T1电影MRI及M型超声检查测得一个心动周期颈总动脉的直径变化而获得量化指标。除了MRI测量值普遍较高外.两种方法对于志愿者及病人的管壁厚度和顺应性评估均具有较高一致性。 展开更多
关键词 颈动脉 扩张能力 内-中膜厚度 MRI 超声 管壁成像 动脉粥样硬化
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Mesoporous bioactive glass composition effects on degradation and bioactivity 被引量:4
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作者 m.schumacher P.Habibovic S.van Rijt 《Bioactive Materials》 SCIE 2021年第7期1921-1931,共11页
Mesoporous bioactive glasses(MBGs)are promising materials for regenerative medicine,due to their favorable properties including bioactivity and degradability.These key properties,but also their surface area,pore struc... Mesoporous bioactive glasses(MBGs)are promising materials for regenerative medicine,due to their favorable properties including bioactivity and degradability.These key properties,but also their surface area,pore structure and pore volume are strongly dependent on synthesis parameters and glass stoichiometry.However,to date no systematic study on MBG properties covering a broad range of possible compositions exists.Here,24 MBG compositions in the SiO_(2)-CaO-P_(2)O_(5) system were synthesized by varying SiO_(2)(60-90 mol%),CaO and P_(2)O_(5) content(both 0 to 40 mol-%),while other synthesis parameters were kept constant.Mesopore characteristics,degradability and bioactivity were analysed.The results showed that,within the tested range of compositions,mesopore formation required a molar SiO_(2) content above 60%but was independent of CaO and P_(2)O_(5) content.While mesopore size did not depend on glass stoichiometry,mesopore arrangement was influenced by the SiO_(2) content.Specific surface area and pore volume were slightly altered by the SiO_(2) content.All materials were degradable;however,degradation as well as bioactivity,i.e.the ability to form a CaP mineral on the surface,depended on stoichiometry.Major differences were found in early surface reactions in simulated body fluid:where some MBGs induced direct hydroxyapatite crystallization,high release of calcium in others resulted in calcite formation.In summary,degradation and bioactivity,both key parameters of MBGs,can be controlled by glass stoichiometry over a broad range while leaving the unique structural parameters of MBGs relatively unaffected.This allows targeted selection of material compositions for specific regenerative medicine applications. 展开更多
关键词 bioactivity bioactive arrangement
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