促红细胞生成素B螺旋表面肽的代谢稳定性结构修饰：设计、合成及其提高的肾保护作用

肾脏缺血缺氧以及再灌注过程都将导致肾小管上皮细胞凋亡,使肾功能严重受损.肾脏的缺血再灌注损伤是移植肾功能延迟恢复的主要原因并能诱导急慢性排斥,影响肾存活率.近年来发现,衍生于促红细胞生成素（EPO）的B螺旋亚基亲水表面序列的肽链（HBSP）,对肾脏缺血再灌注损伤具有显著的保护作用,但其在体内极短的半衰期（约2min）极大地限制了它的临床应用.因此,本研究采用构象约束、全D-构型氨基酸替换和N-端封闭策略,设计了3种类型的EPOB螺旋表面肽衍生物,旨在提高其代谢稳定性环肽的设计采用了对氧化还原稳定的硫醚键和相对刚性的亚砜键两种环合方式.在多肽的合成上,采用微波辅助多肽自动合成和手工合成两种模式有机结合;优化了硫醚环合工艺,应用微波加热进行硫醚环肽的合成,大大提高了产率和效率;利用圆二色（CD）谱确定了亚砜环肽的相对构型.活性实验表明,相对于线性母肽HBSP,本文设计合成的代谢稳定衍生肽对大/小鼠肾脏缺血再灌注损伤均有显著提高的保护作用,且硫醚和R-构型亚砜环肽的肾脏保护活性强于S-构型亚砜环肽.而且,环化确实提高了功能肽的血浆稳定性.因此,本文合成的硫醚环肽一周一次注射剂量等效于线性肽HBSP一日三次剂量对小鼠肾损伤的保护作用.     

The stability analysis of rolling motion of hypersonic vehicles and its validations

The stability of the rolling motion of near space hypersonic vehicles with rudder control is studied using method of qualitative analysis of nonlinear differential equations, and the stability criteria of the deflected rolling motions are improved. The outcomes can serve as the basis for further study regarding the influence of pitching and lateral motion on the stability of rolling motion. To validate the theoretical results, numerical simulations were done for the rolling motion of two hypersonic vehicles with typical configurations. Also, wind tunnel experiments for four aircraft models with typical configurations have been done. The results show that: 1) there exist two dynamic patterns of the rolling motion under statically stable condition. The first one is point attractor, for which the motion of aircraft returns to the original state. The second is periodic attractor, for which the aircraft rolls periodically. 2) Under statically unstable condition, there exist three dynamic patterns of rolling motion, namely, the point attractor, periodic attractor around deflected state of rolling motion, and double periodic attractors or chaotic attractors.     

Circular Controlled Quantum Teleportation by a Genuine Seven-qubit Entangled State

A scheme of circular controlled quantum teleportation, which is a novel version of bidirectional controlled quantum teleportation, is proposed using a specific genuine seven-qubit entangled state as quantum channel, and then it is generalized to the scene with a general genuine seven-qubit entangled state as channel. This means that with the control of the supervisor Daniel while Alice teleportates an unknown qubit state to Bob, Bob can also teleportate an unknown qubit state to Charlie and Charlie can also teleportate an unknown qubit state to Alice circularly, simultaneously. Compared with the BCQT schemes proposed before, the intrinsic efficiency of our scheme is optimal.

     

pH Induces Thermal Unfolding of UTI: An Implication of Reversible and Irreversible Mechanism Based on the Analysis of Thermal Stability, Thermodynamic, Conformational Characterization

The thermal unfolding of Urinary Trypsin Inhibitor (UTI) was studied by several methods: Circular Dichroism (CD), Fluorescence and UV–Vis spectra. Thermal melting of UTI, dissolved in the neutral and basic buffers, was proved to be irreversible and two domains of UTI unfolded simultaneously, but the melting was reversible and the intermediate was observed when pH is lower than 4.2. The result suggested that heat and changes in pH, which had a more important impact on the stabilization of the domain I and the interaction between two domains, might cause different unfolding transitions. A reasonable explanation was deduced for the mechanism of reversible and irreversible thermal unfolding based on the effect of pH on the protein structure, the analysis of thermal transitions and the result of Electron Microscopy: In neutral and basic buffers, the Reactive Central Loop (RCL) in domain II can interact with or insert into the partial expanding domain I and UTI become self-polymerization, however, no aggregation can be observed in acid buffer since low pH and heat destabilized the structure of the domain I and the native conformation can restructure. The interaction between the special structural element RCL and domain I play an important role in the formation of polymer which was different from other two reasons given by other authors—the cleavage of disulfide and the formation of irregular polymer mainly based on hydrophobic interaction.