基于环糊精构建的基因载体进展

安全有效的基因载体对于基因治疗有着重要的潜在价值。相对于病毒性基因载体,化学合成的载体具有低免疫原性,易于大规模生产和生产成本较低的特性,因而受到越来越多的关注,但是非病毒基因载体在转染效率和选择性方面有一定的限制性,当前的主要研究工作集中在这两方面。基于环糊精构建的基因载体,可以有效地提供基因载体的立体构象和功能性的选择性。作为FDA批准的生物材料,环糊精具有无毒和生物降解性,其不但可以保护基因,避免在体内降解,同时有助于通过细胞膜,进入细胞内达到基因转染的作用。环糊精具有大量可修饰的羟基基团,因此对环糊精修饰不但可以通过主客体作用构建超分子体系,并且可以作为多官能团核形成星状高分子,被广泛应用于制备低毒、可降解、靶向性和高效率的转基因载体。目前,环糊精修饰的非病毒正离子载体转移siRNA,已经成功进行了色素瘤的临床试验,取得了很好的治疗效果,表明了环糊精非病毒载体的巨大应用前景。本文对基于环糊精基因载体的最新研究进展进行了综述,详细介绍了基于环糊精的超分子自组装构建的聚轮烷型、侧链分子识别型的基因载体,以及基于环糊精多羟基构型而构建的星型聚合物基因载体和树枝状基因载体,并对环糊精基因载体的优越性和未来应用做了相应的介绍。     

光折变晶体中双光束反向传输引起非稳

实验研究了光折变晶体中双光束反向传输引起非稳的时空特性，从实时信号的功率谱分析和相关维数的计算，确证了系统由准周期运动经周期三到达混沌。     

低压等离子体增强化学汽相沉积法制备立方氮化碳薄膜

用低压等离子体增强化学汽相沉积法和氮化硅中间过渡层的方法，在硅片和玻璃上，制备了立方氮化碳薄膜.用光电子能谱测试了其成分和结合能，薄膜含氮量为42.96%.C1s和N1s的结合能分别为285.01和398.60eV.透射电子显微镜研究表明，制备的氮化碳属于体心立方结构，根据衍射花样，计算的晶格常量a为0.536nm，这与理论预言的结果a为0.53973nm很接近.随着沉积的时间增长，还观测到了氮化碳薄膜的菊池花样.在玻璃上沉积的氮化碳薄膜在可见光和近红外区域是透明的，在400nm处有光吸收. 关键词：     

Enhancement of spin-orbit torque efficiency by tailoring interfacial spin-orbit coupling in Pt-based magnetic multilayers

We study inserting Co layer thickness-dependent spin transport and spin-orbit torques (SOTs) in the Pt/Co/Py trilayers by spin-torque ferromagnetic resonance. The interfacial perpendicular magnetic anisotropy (IPMA) energy density ($K_{\rm s}= 2.7 $ erg/cm$^{2}$, 1 erg = 10$^{-7}$ J), which is dominated by interfacial spin-orbit coupling (ISOC) in the Pt/Co interface, total effective spin-mixing conductance $(G_{\mathrm{eff,tot}}^{\mathrm{\uparrow \downarrow }}=\mathrm{0.42\times }{10}^{15} \mathrm{\Omega }^{-1}\cdot\mathrm{m}^{-2}$) and two-magnon scattering ($\beta_{\mathrm{TMS}}= 0.46 {\mathrm{nm}}^{2}$) are first characterized, and the damping-like torque ($\xi_{\mathrm{DL}}= 0.103$) and field-like torque ($\xi _{\mathrm{FL}}=-0.017$) efficiencies are also calculated quantitatively by varying the thickness of the inserting Co layer. The significant enhancement of $\xi_{\mathrm{DL}}$ and $\xi_{\mathrm{FL}}$ in Pt/Co/Py than Pt/Py bilayer system originates from the interfacial Rashba-Edelstein effect due to the strong ISOC between Co-3d and Pt-5d orbitals at the Pt/Co interface. Additionally, we find a considerable out-of-plane spin polarization SOT, which is ascribed to the spin anomalous Hall effect and possible spin precession effect due to IPMA-induced perpendicular magnetization at the Pt/Co interface. Our results demonstrate that the ISOC of the Pt/Co interface plays a vital role in spin transport and SOTs-generation. Our finds offer an alternative approach to improve the conventional SOTs efficiencies and generate unconventional SOTs with out-of-plane spin polarization to develop low power Pt-based spintronic via tailoring the Pt/FM interface.