The world’s first clinical report on implantation of a 3D-printed mobile cervical prosthesis for the treatment of cervical spondylotic myelopathy was published in China in June 2021[1].It is the continuation of spina...The world’s first clinical report on implantation of a 3D-printed mobile cervical prosthesis for the treatment of cervical spondylotic myelopathy was published in China in June 2021[1].It is the continuation of spinal surgery from spinal stability to mobile artificial cervical spine surgery.The first step forward in the field of mobile artificial cervical surgery is the bullet implant by Fernstroem[2].A variety of mobile discs for the cervical spine(Bryan)were published[3-5].The first with permission for the European Market was the implant from the Charitéin Berlin(Büttner-Janz,1988)[6-7]which I used in Vienna.Although there are some problems,such as motion loss,ossification of intervertebral space,cervical implant displacement and loosening,some cases have achieved certain results[8-9].展开更多
黄河矿 BaCe(CO_3)_2F(a=0.5072(1)nm,c=3.846(1)nm;V=856.8×10^(-3)nm^3;Z=6)晶体结构的重新测定,采用中心对称空间群 R(?)m—D_(3d)~5,基于337个可观察的单晶 X 射线数据(I>2σ_I)和30个可变参数,R=0.031。原子坐标和均方根振...黄河矿 BaCe(CO_3)_2F(a=0.5072(1)nm,c=3.846(1)nm;V=856.8×10^(-3)nm^3;Z=6)晶体结构的重新测定,采用中心对称空间群 R(?)m—D_(3d)~5,基于337个可观察的单晶 X 射线数据(I>2σ_I)和30个可变参数,R=0.031。原子坐标和均方根振幅(据各向异性位移参数计算,O.013—0.025nm)表明,没有必要降低对称性,即没有必要采用相应的非中心对称空间群或其它次群。黄河矿的结构中,原子形成似层状排列,且垂直于 c 轴;碳酸根通过 Ba 与 Ce 的联结形成三维结构。C(1)O_3,和 C(2)O_3,中的 C 原子偏离三个氧组成的平面,其偏离的距离分别为0.0066(15)nm 和 0.0029(15)nm。展开更多
文摘The world’s first clinical report on implantation of a 3D-printed mobile cervical prosthesis for the treatment of cervical spondylotic myelopathy was published in China in June 2021[1].It is the continuation of spinal surgery from spinal stability to mobile artificial cervical spine surgery.The first step forward in the field of mobile artificial cervical surgery is the bullet implant by Fernstroem[2].A variety of mobile discs for the cervical spine(Bryan)were published[3-5].The first with permission for the European Market was the implant from the Charitéin Berlin(Büttner-Janz,1988)[6-7]which I used in Vienna.Although there are some problems,such as motion loss,ossification of intervertebral space,cervical implant displacement and loosening,some cases have achieved certain results[8-9].
文摘黄河矿 BaCe(CO_3)_2F(a=0.5072(1)nm,c=3.846(1)nm;V=856.8×10^(-3)nm^3;Z=6)晶体结构的重新测定,采用中心对称空间群 R(?)m—D_(3d)~5,基于337个可观察的单晶 X 射线数据(I>2σ_I)和30个可变参数,R=0.031。原子坐标和均方根振幅(据各向异性位移参数计算,O.013—0.025nm)表明,没有必要降低对称性,即没有必要采用相应的非中心对称空间群或其它次群。黄河矿的结构中,原子形成似层状排列,且垂直于 c 轴;碳酸根通过 Ba 与 Ce 的联结形成三维结构。C(1)O_3,和 C(2)O_3,中的 C 原子偏离三个氧组成的平面,其偏离的距离分别为0.0066(15)nm 和 0.0029(15)nm。