人参皂苷Rb1单克隆抗体的制备与鉴定

用人参皂苷Rb1分别与牛血清白蛋白(BSA)和卵清蛋白(OVA)反应合成了交联抗原GRb1-BSA(GRb1与BSA的结合比为10∶1)和GRb1-OVA(GRb1与OVA的结合比为8∶1)。以GRb1-BSA为免疫原,分5次免疫3只BALB/C小鼠,取免疫脾细胞与小鼠骨髓瘤细胞进行融合,Hat筛选,有限稀释法克隆。建立分泌单克隆抗体的杂交瘤细胞系。采用ELISA(酶联免疫吸附测定)间接法和竞争法检测抗体的特异性。结果获得了一只小鼠分泌抗体效价达1∶16000,并获得两株分泌GRb1的单克隆抗体的细胞系,分别命名为1F7和1G3,单抗检测显示在0.01~1μg/mL呈线性关系,GRb1的检测范围达50~350 ng/mL,两株单抗针对相同的抗原决定簇,制备的单克隆抗体可用于GRb1含量的检测和分离。     

A saturated discrete particle model and characteristic-based SPH method in granular materials

Based on the discrete particle model for solid-phase deformation of granular materials consisting of dry particulate assemblages, a discrete particle–continuum model for modelling the coupled hydro-mechanical behaviour in saturated granular materials is developed. The motion of the interstitial fluid is described by two parallel continuum schemes governed by the averaged incompressible N–S equations and Darcy's law, respectively, where the latter one can be regarded as a degraded case of the former. Owing to the merits in both Lagrangian and mesh-free characters, the characteristic-based smoothed particle hydrodynamics (SPH) method is proposed in this paper for modelling pore fluid flows relative to the deformed solid phase that is modelled as packed assemblages of interacting discrete particles. It is assumed that the formulation is Lagrangian with the co-ordinate system transferring with the movement of the solid particles. The assumed continuous fluid field is discretized into a finite set of Lagrangian (material) points with their number equal to that of solid particles situated in the computational domain. An explicit meshless scheme for granular materials with interstitial water is formulated. Numerical results illustrate the capability and performance of the present model in modelling the fluid–solid interaction and deformation in granular materials saturated with water. Copyright © 2007 John Wiley & Sons, Ltd.     

压电传感实时监测氯霉素分子印迹聚合物的原位合成

氯霉素是一种广谱抗菌药物,但食物中的氯霉素残留物质对人类的健康构成了巨大威胁。该问题已引起国际组织和世界上许多国家和地区的高度重视。通过压电传感器检测残余的氯霉素,具有无需适用放射性材料和预处理时间短的优势。因此,合成人工模拟单克抗体——氯霉素分子印记聚合物非常有意义。实验在10μL的压电传感器的金电极上,原位合成氯霉素印迹聚合物。实验结果表明,聚合反应过程是二级反应。     

Two organic–inorganic hybrid Schiff base copper materials: synthesis and their catalytic properties for constructing C–N bonds

Abstract

Two Schiff base copper complexes: [Cu(H₂O)₂(HL¹)]·2H₂O (1) (H₃L¹ =2-((2,4-dihydroxybenzylidene)amino)acetic acid) and [Cu(L²) (CH₃OH)]₄ (2) (H₂L² = 3-phenyl-2-(2-hydroxy-5-chlorobenzylideneamino)propane-1-ol), have been simply synthesized and fully characterized. Single crystal X-ray diffraction (SXRD) revealed that 1 consists of one five-coordinated copper atom and one deprotonated Schiff base ligand HL¹. The copper atom in 1 showed the distorted tetragonal pyramid geometry, whereas, four copper atoms in 2 were six-coordinated and exhibited the distorted octahedron geometry. Importantly, two Schiff base complexes were further used as catalysts in Chan–Lam coupling reaction and 2 demonstrated excellent catalytic performance in construction of C–N bonds (yields up to 87%).     

Immobilisation of TiO2-nanoparticles on sewage sludge and their adsorption for cadmium removal from aqueous solutions

In this study, pure TiO₂-nanoparticles and TiO₂/sewage sludge (TS) as biomass material were synthesised via a sol–gel method. The adsorption potential of nanosized TiO₂ and TS for removal of Cd(II) was investigated in a batch system. The prepared adsorbents were characterised using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The XRD analysis showed that pure TiO₂ is in amorphous phase before calcination and in anatase phase at annealing temperature of 400 °C. TiO₂/sewage sludge that calcined at 400 °C (TS⁴⁰⁰) was found to be the best adsorbent for cadmium removal from aqueous solution. Kinetic and isotherm studies were carried out by considering the parameters, pH, initial concentration and contact time. The optimum pH value for Cd(II) adsorption onto TS⁴⁰⁰ was found to be 6. Langmuir isotherm showed better fit than Freundlich isotherm and the maximum adsorption capacity was found to be 29.28 mg/g which is higher than that of many other adsorbents reported in literature. The sorption kinetic data were well fitted with a pseudo-second-order model. These results demonstrated that TS⁴⁰⁰ was readily prepared and is the promising and effective solid material for the removal of Cd(II) from aqueous solutions.     

In situ synthesis of hydroxyapatite-grafted titanium nanotube composite

ABSTRACT

The present study is an investigation to demonstrate the effectiveness of in situ approach in the synthesis of hydroxyapatite-grafted titanium nanotube composite (HA-TNT). This method involves combining the process of HA sol–gel and rapid breakdown anodisation of titanium in a novel solution consisting of NaCl and N₃PO₄. This new synthesis approach produced a uniform dispersion of Anatase and Rutile phases of TiO₂ nanotubes with minimal agglomeration in the matrix of crystalline HA. The characterisation of homogenised HA-TNT composite was investigated via field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), transmission electron microscope (TEM) and X-ray diffraction (XRD). FESEM and TEM images indicated the nanostructure of composite with TiO₂ nanotube diameter of approximately 10 nm. XRD and EDS analyses confirmed the formation of HA crystalline with the Ca/P ratio of 1.58 and formation of Anatase and Rutile phase of TiO₂ nanotubes.     

Influence of Coating Parameter and Sintering Atmosphere on the Corrosion Resistance Behavior of Electrophoretically Deposited Composite Coatings

The purpose of this study is to synthesize and characterize nanosized titania (TiO₂), zinc oxide (ZnO), and its composite coating on Ti–6Al–4V to enhance its corrosion protection behavior in Ringer's solution. Nanosized powders of TiO₂ and ZnO was characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and scanning electron microscopy - energy dispersive atomic spectroscopy (SEM-EDAX) analysis. As a result of antibacterial activity, both ZnO and TiO₂/ZnO have produce remarkable inhibition zone on Escherichia coli. The antibacterial activity of composites are due to the combined effect of ZnO on TiO₂. The adherence and surface uniformity of TiO₂/ZnO composite film on titanium implant was examined by optical microscopy and Vickers microhardness test. Corrosion resistant behavior of the coating on titanium implant was investigated by tafel polarization and impedance analysis. The composite coatings on Ti–6Al–4V have produced improved corrosion resistance with a pronounced shift in the anodic corrosion potential (E_corr) with a corresponding less corrosion current density (I_corr) compared to monophase coating. Similar results have been obtained for impedance analysis which indicated a reduction in double layer capacitance (C_dl) and with enhancement in charge transfer resistance (R_ct). These observations suggest improved corrosion resistance property of TiO₂/ZnO composite coating on Ti–6Al–4V.     

Variation of optical properties,rheology, and microstructure in fullerene/poly(vinyl pyrrolidone) nanofluids with fullerene content in n-butanol

In this study, we report non-linear variation of optical and rheology properties in fullerene (C₆₀)/poly(vinyl pyrrolidone) (PVP) nanofluids (NFs) with C₆₀-content (C) in an alcoholic medium. From the absorption spectra, we found that the absorbance maximum (α_max) follows a non-linear path with C-value due to a donor–acceptor PVP → C₆₀ charge transfer in a C₆₀/PVP complex. The α_max value reaches maximum at a specific C₆₀-content of 13.9 μM due to percolation effect and then starts decreasing with a further increase in C-value over the subsequent region covered in this experiment. Models were proposed to show donor–acceptor interaction between C₆₀ and PVP. The molar extinction coefficient also drops through a peak maximum at 13.9-µM C₆₀. Regardless of the C-values, shear-thinning behavior was found in all NFs. The shear viscosity (η) value, which decreases with shear rate value over 5 to 100 s^?1, is shown to be increasing non-linearly against the C-value. The η-value varies non-linearly with C₆₀-content and shows a dip at a point near 13.9-µM C₆₀. High-resolution transmission electron microscope images reveal that the size of C₆₀/PVP nano-assemblies increases with C-value as PVP is anchoring C₆₀ molecules in specific structures.     

Evaluation of mechanical properties using spherical ball indentation and coupled finite element–element-free galerkin approach

In the present work, the mechanical properties of pressure tube material (Zr-Nb2.5) are evaluated using the coupled finite element–element-free Galerkin approach. Penalty approach is used to impose contact constraints and non-penetration condition at the interface. An efficient node-to-segment algorithm is employed to model the contact behavior. An updated Lagrangian approach is used to model the large deformation. Loading and unloading response of the indentation process is analyzed using von-Mises and Gurson-Tvergaard-Needleman (GTN) plasticity models. In multiple indentations, the indentation depth is progressively increased up to a maximum specified limit with partial unloading. Load-indentation depth curves are used to extract the flow properties of the material.     

Modeling,Sensing, and Interpretation of Viscoelastic Contact Interface

Soft robotics is important in the next generation of robots because of the rapidly increasing need for robotics in biomedical applications and the advantages of providing a soft interface for interaction with the physical environment in service robots and other applications. It is indispensable to understand the fundamental behavior of such contact interface, typically viscoelastic, in order to accurately predict the actual elastic and temporal responses of the contact and to successfully control it. Viscoelasticity is a phenomenon of time-dependent strain and/or stress in soft materials. It is therefore important to model such behavior and to study the effects of such time-dependent strain and stress on stability and behavior at the contact interface. The contribution of this paper is the introduction of a novel latency model, which is a nonlinear model with differential equations that govern viscoelastic materials. Latency model describes various features of viscoelastic materials, such as stress relaxation and strain creep. The theoretical modeling was supported by experimental results in which we found two types of relaxation. Type I relaxation is well documented in existing literature but Type II relaxation has not been elaborated previously with the physical insights provided in this paper. The proposed theory can unify both types of time-dependent relaxation responses for modeling, sensing, and interpretation of viscoelastic contact interface.