α-Mangostin exhibits antidepressant-like effects mediated by the modification of GABAergic,serotonergic and dopaminergic systems

Abstract

The present study explored the antidepressant-like activity of α-mangostin (α-MG) and the possible mechanism in this process in the tail suspension test (TST) in mice. The results revealed that α-MG (5?mg/kg, i.p.) exhibited markedly antidepressant-like activity, which could be reversed by pretreatment with haloperidol (a non-selective D₂ receptor antagonist), bicuculline (a competitive GABA antagonist), p-chlorophenylalanine (an inhibitor of 5-HT synthesis). Meanwhile, α-MG also effectively increased the brain DA, 5-HT and GABA levels in mice exposed to TST, indicating that the antidepressant-like effect of α-MG might be mediated by the GABAergic, serotonergic and dopaminergic systems.

     

悬浮液直接进样ICP–OES法测定高纯氧化铝中的铁、钛、硅、铬

采用悬浮液直接进样电感耦合等离子体发射光谱法(ICP–OES)测定高纯氢氧化铝中铁、钛、硅、铬的含量。悬浮液用电磁搅拌器搅拌,均匀地分散在溶液中,通过仪器蠕动泵进入雾化室,均匀无阻地导入ICP光源。Fe,Ti,Si,Cr的分析谱线分别为259.940,336.112,251.611,205.552 nm;RF功率为1 300W,等离子体气流量为13.0 L/min,雾化器气体流量为0.60 L/min,辅助气流量为1.00 L/min。Fe,Ti,Si,Cr的质量浓度分别在0.0~30.0,0.0~15.0,0.0~90.0,0.0~15.0μg/m L范围内与信号强度呈良好的线性,线性相关系数均大于0.999,方法的检出限为0.027 6~0.993 9μg/m L,测量结果的相对标准偏差为0.65%~6.84%(n=11),回收率为95.0%~104.8%。该法抗干扰能力强、线性范围宽,适用于高纯氢氧化铝中铁、钛、硅、铬含量的分析。     

PREPARATION AND CHARACTERIZATION OF SUPERPARAMAGNETIC FUNCTIONAL POLYMERIC MICROPARTICLES

Superparamagnetic poly(styrene-divinylbenzene-glycidyl methacrylate) (Pst-DVB-GMA) microparticles were prepared via a modified suspension polymerization process. A magnetic fluid was first prepared by a chemical co-precipitation method. Then magnetic microparticles were produced by mixing the monomers and the magnetic fluid with water in the presence of a stabilizer poly(vinyl pyrrolidone) (PVP) to form a suspension, and finally benzoyl peroxide was added to initiate the co-polymerization. The morphology and magnetic properties of the microparticles were examined by TEM and VSM. The spherically shaped microparticles, with a size range of 4 to 7 pm, showed distinct superparamagnetic characteristics. XRD was used to investigate the structure of the magnetite particles dispersed in the polymer matrix. The microparticles with epoxy groups on their surface can be applied directly to the seoaration of biomolecules.     

Non-linear vibrations of suspension bridges with external excitation

Non-linear coupled vertical and torsional vibrations of suspension bridges are investigated. Method of Multiple Scales, a perturbation technique, is applied to the equations to find approximate analytical solutions. The equations are not discretized as usually done, rather the perturbation method is applied directly to the partial differential equations. Free and forced vibrations with damping are investigated in detail. Amplitude and phase modulation equations are obtained. The dependence of non-linear frequency on amplitude is described. Steady-state solutions are analyzed. Frequency-response equation is derived and the jump phenomenon in the frequency-response curves resulting from non-linearity is considered. Effects of initial amplitude and phase values, amplitude of excitation, and damping coefficient on modal amplitudes, are determined.     

Rheology of coal suspensions

Proper design of operations encountered in preparation, transport and employment of suspensions like coal slurries and coal-oil mixtures require an accurate knowledge of their rheological behaviour.Such concentrated suspensions generally exhibit non-Newtonian behaviour (shearthinning) which is more pronounced at higher coal concentrations. The nature of the dispersing medium influences the aggregation state of the disperse phase and, consequently, affects the stability and the rheology of the systems. In the present paper coal suspensions prepared with different dispersing media and covering a wide range in solid phase concentration are studied, by using a rotational coaxial cylinders viscometer.Different models have been taken into consideration for correlating experimental data. In particular, in order to describe the dependence of viscosity on shear rate and solid phase concentration, the suitability of the model suggested by Smith and Bruce is evaluated. Accordingly, the aggregation state of the disperse phase as well as its dependence on shear rate and dispersing medium can be estimated.     

悬挂减振原理在图书馆书库设计中的应用分析

 应用悬挂减振原理，在图书馆书库设计中将书架设计成悬挂体系， 通过结构体系的时程分析和谱分析得出，该方法较一般的书库设计方法 有明显的减振效果，还可减少楼板荷载，减少楼板厚度，有良好的应用 价值.     

纤维悬浮液搅拌流动的数值模拟

由于缺乏适当的本构方程，对纤维悬浮液流动的研究一直局限于纤维的牛顿流体悬浮液。本文采用ＭＵＣＭ模型对作者最近提出的纤维Ｏｌｄｒｏｙｄ－Ｂ流体悬浮液的本构方程作了改进，并对锚式桨搅拌槽的二维Ｏｌｄｒｏｙｄ－Ｂ流体和牛顿流体纤维悬浮液搅拌流动作了数值模拟。模拟的结果表明，本文所用的模型和方法能有效地抑制过大局部应力的影响并合理地处理流体的记忆效应。     

Experimental studies of suspended ferromagnetic fibers in a magnetic field

The analysis of the rotation of a ferromagnetic ellipsoid suspended in a Newtonian fluid and subjected to a uniform magnetic field is extended to include a long, slender cylindrical fiber which is magnetically saturated. Experimental observations of rotating nickel cylinders with aspect ratiosL/D ranging from 5 to 40 agree with the theoretical predictions that: (1) the proper magnetoviscous time constant for the motion is _MV = _s/µ ₀ M _s ² , (2) larger fiber aspect ratios result in considerably longer orientation times; and (3) the strength of the applied external field has only a slight effect on the overall fiber rotation, and has no effect on the maximum angular velocity achieved. Quantitative agreement of theory and experiments is obtained for fibers withL/D 20; for the shorter fibers, the theory tends to overpredict the fiber rotation rate by as much as 30%. D diameter of the cylinder - D ^P (r) position-dependent demagnetization tensor, implicitly defined in eq. (2.5) - D _xx,D _yy,D _zz volume-averaged demagnetizing factors for an ellipsoid equivalent to a uniformly magnetized cylinder, defined in eq. (2.6) - H _i ;H _i magnetic field inside a ferromagnetic body; magnitude ofH _i - H ₀;H ₀ magnetic field applied by external sources; magnitude ofH ₀ - k geometric parameter in the hydrodynamic resistance of a body rotating in a Newtonian fluid, eq. (2.2) - L length of the cylinder - L ^(h);L _z ^(h) hydrodynamic torque exerted on a rotating body; thez-component ofL ^(h) on the cylinder - L ^(m);L _z ^(m) magnetic torque exerted on a magnetic body in a magnetic field, eq. (2.4); thez-component ofL ^(m) on the cylinder - M the magnetization of a magnetic material - M _s the saturation magnitude ofM, approached by all ferromagnetic materials asH _i becomes large - r position vector of a point within a ferromagnetic body - V volume of a magnetic particle - x, y, z rectangular coordinate axes fixed in the cylinder according to figure 1 - angle of inclination of the axis of the cylinder with respect toH ₀ - shear rate - small parameter of slender body theory,=1/ln (2L/D) - _s constant viscosity of the suspending fluid - µ ₀ the magnetic permeability of free space,µ ₀=4 · 10^–7 H/m - _MV the magnetoviscous time constant, a characteristic time for a process involving a competition of viscous and magnetic stresses - ₁ the first normal-stress coefficient - ; _z angular velocity of a rotating body; angular velocity of a cylinder about thez-axis, _z =– d/dt