Molecular Dynamics Study of Stability of Solid Solutions and Amorphous Phase in the Cu-Al System

The relative stability of fee and bcc solid solutions and amorphous phase with different compositions in the Cu-Al system is studied by molecular dynamics simulations with n-body potentials. For CU1-xAlx alloys, the calculations show that the fee solid solution has the lowest energies in the composition region with x 〈 0.32 or x 〉 0.72, while the bcc solid solution has the lowest energies in the central composition range, in agreement with the ball-milling experiments that a single bcc solid solution with 0.30 〈 x 〈 0.70 is obtained. The evolution of structures in solid solutions and amorphous phase is studied by the coordination number （CN） and bond-length analysis so as to unveil the underlying physics. It is found that the energy sequence among three phases is determined by the competition in energy change originating from the bond length and CNs （or the number of bonds）.     

艾泽尔斯贝格（Eiselsberg，Anton，Freiherr von baron of,1860-1939）奥地利医学家（Hakeem，Austria）

艾泽尔斯贝格对甲状腺及中枢神经系统外科进行了重要的研究工作。曾在维也纳师从比尔罗特并成为其助手，1884年在维也纳获医学博士学位。1890年描述了甲状腺手术后经常出现的“破伤风感染”。两年后用切除甲状旁腺的方法实验性地引起肌强直症状。后又研究甲状腺肿瘤，对脑下垂体外科亦作出贡献。在维也纳任教授时有奥地利神经外科泰斗之称。是现代胃肠外科的创始人之一。首先在欧洲切除脊柱肿瘤，创立了脑外科，又研究过链球菌感染。     

Sigma受体显像剂

σ受体与细胞功能、生物过程以及许多疾病关系密切。σ1受体已成为发展精神分裂症、抑郁症、早老性痴呆和帕金森病等中枢神经系统（CNS）神经精神疾病药物新的靶点，而σ2受体是肿瘤增殖的生物标志。σ1受体显像剂的研制将为CNS神经精神疾病提供敏感特异的诊断方法，而σ2受体显像剂的研究将为肿瘤的早期诊断提供灵敏的分子探针。本文综述了σ受体显像剂的研究进展，结合σ受体显像剂的用途，详细讨论了不同σ受体显像剂的设计方法，并对其未来发展作了展望。     

New Stereoselective Synthesis of 4-Butyl-α-agarofuran

A potent anxiolytic 4-butyl-α-agarofuran (AF-5) was synthesized from ( )dihydrocarvone. Acid catalyzed hydration of ( )dihydrocarvone and interconversion with β-O-ketone 8 and the key intermediate α,β-unsaturated ketone 5 made this synthesis more practical.     

低水平铅暴露对中枢神经系统的毒性作用及其分子机制

综述近年来关于低水平铅暴露对神经系统的作用以及神经毒物化学机制的研究进展。     

基于香豆素结构的高选择性、高灵敏度的苯硫酚荧光探针及其应用

苯硫酚在有机合成中具有重要作用,被广泛应用于农药和医药各种中间体的制备。然而,长期接触水或者土壤中的苯硫酚会对健康造成一系列严重危害,包括中枢神经系统受损,心率变快,肌肉萎缩,下肢瘫痪,昏迷甚至死亡。目前,能够专一性检测苯硫酚的荧光探针的文献报道并不多。此外,在这些已报道的苯硫酚探针中,有些表现出较弱的荧光强度,有些必须以有机溶剂作为共同溶剂,有些在实际检测中需要使用过高的pH值环境,只有非常少的探针能够在     

Synchronization transition of a coupled system composed of neurons with coexisting behaviors near a Hopf bifurcation

The coexistence of a resting condition and period-1 firing near a subcritical Hopf bifurcation point, lying between the monostable resting condition and period-1 firing, is often observed in neurons of the central nervous systems. Near such a bifurcation point in the Morris-Lecar （ML） model, the attraction domain of the resting condition decreases while that of the coexisting period-1 firing increases as the bifurcation parameter value increases. With the increase of the coupling strength, and parameter and initial value dependent synchronization transition processes from non-synchronization to compete synchronization are simulated in two coupled ML neurons with coexisting behaviors： one neuron chosen as the resting condition and the other the coexisting period-1 firing. The complete synchronization is either a resting condition or period-1 firing dependent on the initial values of period-1 firing when the bifurcation parameter value is small or middle and is period- 1 firing when the parameter value is large. As the bifurcation parameter value increases, the probability of the initial values of a period- 1 firing neuron that lead to complete synchronization of period- 1 firing increases, while that leading to complete synchronization of the resting condition decreases. It shows that the attraction domain of a coexisting behavior is larger, the probability of initial values leading to complete synchronization of this behavior is higher. The bifurcations of the coupled system are investigated and discussed. The results reveal the complex dynamics of synchronization behaviors of the coupled system composed of neurons with the coexisting resting condition and period-1 firing, and are helpful to further identify the dynamics of the spatiotemporal behaviors of the central nervous system.     

中枢神经系统血管母细胞瘤细胞与人脑神经元细胞差异蛋白质分析

以人工培养的中枢神经系统血管母细胞瘤(Central nervous system hemangioblastoma,HB)细胞为研究对象,发展了蛋白质组学分析方法,鉴定了HB细胞与人脑神经元细胞的差异蛋白质.采用在线HPLC串联LTQ-Orbitrap质谱鉴定样品的可溶性蛋白质,得到了HB细胞的蛋白质组表达谱.HB细胞鉴定得到674个蛋白质,神经元细胞鉴定获得531个蛋白质.根据基于肽段鉴定的蛋白质组半定量分析方法对质谱数据进行蛋白质的差异比较分析,发现了波形蛋白(Vimentin),14-3-3 epsilon蛋白和碳酸酐酶Ⅱ(Carbonic anhydrase Ⅱ,CA Ⅱ)等在HB细胞中表达量发生明显变化的蛋白质,并对其进行了免疫组织化学染色分析.结果显示,波形蛋白(Vimentin)、14-3-3 epsilon蛋白以及碳酸酐酶Ⅱ(CA Ⅱ)等蛋白质表达量的改变与HB的发病密切相关,对探索HB的起源有重要意义.     

A novel four-node quadrilateral element with continuous nodal stress

Formulation and numerical evaluation of a novel four-node quadrilateral element with continuous nodal stress（Q4-CNS）are presented.Q4-CNS can be regarded as an improved hybrid FE-meshless four-node quadrilateral element（FE-LSPIM QUAD4）, which is a hybrid FE-meshless method.Derivatives of Q4-CNS are continuous at nodes, so the continuous nodal stress can be obtained without any smoothing operation.It is found that,compared with the standard four-node quadrilateral element（QUAD4）,Q4- CNS can achieve significantly better accuracy and higher convergence rate.It is also found that Q4-CNS exhibits high tolerance to mesh distortion.Moreover,since derivatives of Q4-CNS shape functions are continuous at nodes,Q4-CNS is potentially useful for the problem of bending plate and shell models.