A Self‐Digitization Dielectrophoretic (SD‐DEP) Chip for High‐Efficiency Single‐Cell Capture,On‐Demand Compartmentalization,and Downstream Nucleic Acid Analysis

The design and fabrication of a self‐digitization dielectrophoretic (SD‐DEP) chip with simple components for single‐cell manipulation and downstream nucleic acid analysis is presented. The device employed the traditional DEP and insulator DEP to create the local electric field that is tailored to approximately the size of single cells, enabling highly efficient single‐cell capture. The multistep procedures of cell manipulation, compartmentalization, lysis, and analysis were performed in the integrated microdevice, consuming minimal reagents, minimizing contamination, decreasing lysate dilution, and increasing assay sensitivity. The platform developed here could be a promising and powerful tool in single‐cell research for precise medicine.     

Novel fluorosilicone thermoplastic vulcanizates prepared via core‐shell dynamic vulcanization: Effect of fluororubber/silicone rubber ratio on morphology,crystallization behavior,and mechanical properties

Recently, we have reported a novel core‐shell dynamic vulcanization method to prepare poly(vinylidene fluoride) (PVDF)/fluororubber (FKM)/silicone rubber (SR) thermoplastic vulcanizates (TPVs) with cross‐linked rubber core‐shell particles. However, the shell thickness on the properties has not been studied in detail. Herein, these PVDF‐based TPVs different FKM‐shell thickness were prepared by changing FKM/SR ratios. The effect of FKM‐shell/SR‐core ratio on morphology, crystallization, and mechanical properties of the ternary TPVs was studied. The results showed that the FKM shell had more positive effect on interfacial‐induced crystallization behavior than the SR core due to its better compatibility with PVDF. When the FKM/SR ratio was <1, FKM was not enough to encapsulate SR completely, which resulted in the formation of imperfect core‐shell structure. However, when the FKM/SR ratio was >1, perfect core‐shell structure was formed. Therefore, the mechanical properties improved with increasing FKM content; especially, a remarkable improvement was observed when FKM/SR ratio was >1. This study could provide more information for the design of TPVs with core‐shell structure.     

Dynamic and Isothermal Thermogravimetric Degradation of Poly(vinyl Chloride)/Chlorinated Poly(ethylene) Blends

The thermal degradation of poly(vinyl chloride)/chlorinated poly(ethylene) (PVC/CPE) blends of different compositions was investigated by means of dynamic and isothermal thermogravimetric analysis in flowing atmosphere of nitrogen. Kinetic parameters (the apparent activation energy E, and pre-exponential factor Z) were calculated after Flynn-Wall-Ozawa method for the first stage of dynamic degradation of PVC/CPE blends, and after Flynn method for the isothermal degradation. In both cases, there is the compensation dependence between the values E and logZ. The values of compensation ratios as well as the characteristics of TG and DTG curves, confirm the stabilizing effect of CPE on PVC dehydrochlorination. This revised version was published online in July 2006 with corrections to the Cover Date.     

Calorimetric Investigation of Conversion to The Most Stable Subgel Phase of Phosphatidylethanolamine-water System

The conversion of either the gel or the liquid crystal phase to the most stable subgel phase in dimyristoylphosphatidylethanolamine (DMPE)-water system at a water content of 25 mass% was studied by differential scanning calorimetry and isothermal calorimetry. The calorimetric experiments were performed for two samples depending on whether the thermal treatment of cooling to -60°C was adopted or not. In DSC of varying heating rate, exothermic peaks due to the partial conversion were observed at either temperatures just below the gel-to-liquid crystal phase transition at 50°C or temperatures where the liquid crystal phase is present as a metastable state. The enthalpies of conversion for both the gel and the liquid crystal phase were measured directly by the isothermal calorimetries at 47 and 53°C, respectively, where the exothermic peaks were observed by DSC and were compared with the enthalpy difference between the gel and subgel phases and that between the liquid crystal and subgel phases. This revised version was published online in July 2006 with corrections to the Cover Date.     

Solubilization and Hydrolysis of Ovotransferrin Solubilization of α-chymotrypsin. Enthalpy changes for three processes

At 298.15 K, the solubilization of hen ovotransferrin at buffered pH 7.8 (0.08 M Tris⋅HCl buffer, containing 0.1 M CaCl₂) and the solubilization of α-chymotrypsin (from bovine pancreas) at non-buffered pH 3.0 (0.001 M HCl) both resulted in large exothermic reactions, being the apparent ΔHs –2485 in the first case and –780.1 kJ mol^–1 in the second case, respectively. By contrast, the complete hydrolysis of ovotransferrin (pH 7.8) achieved by using a-chymotrypsin (pH 3.0) gave an endothermic reaction with ΔH=+31.84 kJ mol^–1. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis and evaluation of a tri-armed molecular receptor for recognition of mercury and cyanide toxicants

A tri-armed-pyrene-linked molecular receptor, 5 has been designed, synthesised and evaluated for ionic recognition. It has been observed that the synthesised molecular receptor can recognise mercury and cyanide ions through a change in colour, UV–Vis and fluorescence intensity. The binding stoichiometry of the receptor and these ionic species has been found to be 1:1 through Job’s plots, Benesi–Hildebrand plots and isothermal titration calorimetry (ITC).     

Equilibrium analysis for a mass-conserving model in presence of cavitation

We study the existence of equilibrium positions for the load problem in Lubrication Theory. The problem consists of two surfaces in relative motion separated by a small distance filled by a lubricant. The system is described by the modified Reynolds equation (Elrod–Adams model) which describes the behavior of the lubricant and an extra integral equation given the balance of forces. The balance of forces allows to obtain the unknown position of the surfaces, defined with one degree of freedom.     

存在滑移时两圆球间的幂律流体挤压流动

基于Reynolds润滑理论分析了壁面滑移对任意圆球颗粒间幂律流体的挤压流动的影响。研究表明有壁面滑移时挤压流动的粘性力可通过引进本文定义的滑移修正系数分离出无滑移解。推导出的挤压力滑移修正系数是一积分表达式，依赖于滑移参数、幂律指数、球间隙和积分上限。一般地壁面滑移导致粘性力减小，粘性力的减小量随幂律指数的增大而增大，表明壁面滑移对剪切增稠流变材料有更大的影响；粘性力的减小量还随着滑移参数的增大而增加，而这恰与假设相符合；粘性力的减小量又随球间隙减小或积分上限的增大（从液桥情况到完全浸渍）而减小直到趋于常数，这一特性在离散元模拟时可以有效地减少计算量。