中空球状水铝英石/SBR纳米复合材料的制备与性能研究

将天然中空球状水铝英石在水中进行提纯分散处理,采用乳液共混共凝法制备中空球状水铝英石/SBR纳米复合材料,并对其性能进行研究.场发射环境扫描电子显微镜和透射电子显微镜观察表明,中空球状水铝英石原矿粉以聚集体形式存在,聚集体直径约为200 nm,组成聚集体的中空球状小颗粒直径约为13 nm;水铝英石在复合材料中分散良好.与采用直接共混法制备的复合材料相比,采用乳液共混共凝法制备的复合材料定伸应力较小,拉伸强度较大.     

Metastatic Voyage of Ovarian Cancer Cells in Ascites with the Assistance of Various Cellular Components

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy and has a unique metastatic route using ascites, known as the transcoelomic root. However, studies on ascites and contained cellular components have not yet been sufficiently clarified. In this review, we focus on the significance of accumulating ascites, contained EOC cells in the form of spheroids, and interaction with non-malignant host cells. To become resistant against anoikis, EOC cells form spheroids in ascites, where epithelial-to-mesenchymal transition stimulated by transforming growth factor-β can be a key pathway. As spheroids form, EOC cells are also gaining the ability to attach and invade the peritoneum to induce intraperitoneal metastasis, as well as resistance to conventional chemotherapy. Recently, accumulating evidence suggests that EOC spheroids in ascites are composed of not only cancer cells, but also non-malignant cells existing with higher abundance than EOC cells in ascites, including macrophages, mesothelial cells, and lymphocytes. Moreover, hetero-cellular spheroids are demonstrated to form more aggregated spheroids and have higher adhesion ability for the mesothelial layer. To improve the poor prognosis, we need to elucidate the mechanisms of spheroid formation and interactions with non-malignant cells in ascites that are a unique tumor microenvironment for EOC.     

Rapid preparation of monodisperse biodegradable polymer nanospheres using a membrane emulsification technique under low gas pressure

Nanospheres of poly(lactide-co-glycolide) (PLGA), a biodegradable polymer, have been prepared using the conventional solvent diffusion method. In this study, a method combining the solvent diffusion method and a two-step (premix) membrane emulsification technique is proposed for the preparation of monodisperse PLGA nanospheres with a diameter of 200 nm. The monodispersity of the PLGA nanospheres was higher than that of nanospheres obtained by the conventional solvent diffusion method. Generally, preparation of small particles or droplets by the membrane emulsification technique requires a supply of high-pressure nitrogen gas to force the emulsion or dispersion solution through the small pores of the membrane. However, in the technique proposed here, low-pressure nitrogen gas (0.02–0.11 kgf/cm²) is sufficient. Thus, using this technique, one can obtain monodisperse PLGA nanospheres with a diameter of 200 nm in a relatively short period of time under low-pressure nitrogen gas.     

Observation of non-chemical equilibrium effect on Ar-CO2-H2 thermal plasma model by changing pressure

The authors developed a two-dimensional one-temperature chemical non-equilibrium (1T-NCE) model of Ar-CO₂-H₂ inductively coupled thermal plasmas (ICTP) to investigate the effect of pressure variation. The basic concept of one-temperature model is the assumption and treatment of the same energy conservation equation for electrons and heavy particles. The energy conservation equations consider reaction heat effects and energy transfer among the species produced as well as enthalpy flow resulting from diffusion. Assuming twenty two (22) different particles in this model and by solving mass conservation equations for each particle, considering diffusion, convection and net production terms resulting from hundred and ninety eight (198) chemical reactions, chemical non-equilibrium effects were taken into account. Transport and thermodynamic properties of Ar-CO₂-H₂ thermal plasmas were self-consistently calculated using the first-order approximation of the Chapman-Enskog method. Finally results obtained at atmospheric pressure (760 Torr) and at reduced pressure (500, 300 Torr) were compared with results from one-temperature chemical equilibrium (1T-CE) model. And of course, this comparison supported discussion of chemical non-equilibrium effects in the inductively coupled thermal plasmas (ICTP).     

Multi-class grasping classifiers using EEG data and a common spatial pattern filter

This paper describes the classification of various human actions from brain activity. In particular, we focus on grasping movements and estimate grasping patterns from electroencephalogram (EEG) data. EEG data is converted to grasping features by using a common spatial pattern filter (CSP filter), and the features are subsequently classified into grasping categories by using the k-nearest neighbor method. We tested the pipeline of feature extraction and classification on the EEG dataset. The EEG data were acquired while participants grasped an object according to the Cutkosky’s grasping taxonomy, in which grasping movements are categorized into nine power-type grasping patterns and seven precision-type grasping patterns. The best classification rate for 9-class power-type grasping patterns was 48% and for 7-class precision-type grasping patterns was 40%.     

Investigation for Necessity of Dispersivity and Tortuosity in the Dusty Gas Model for a Binary Gas System in Soil

Diffusion, dispersion, and advection are important processes in multi-gas systems in soils. To date, both Fick's model and the Dusty Gas (DG) model have been used to model the movement of gases in these systems. Dispersion is included in the dispersion-advection equation with Fick's Model for the movement of gases in gas-phase of soil, yet the movement of gases in multi-component gas-soil systems is considered to be expressed more accurately by the DG model than by Fick's model. However to date, no study has investigated the necessity of considering dispersion in the Dusty Gas (DG) model. We carried out column experiments for nitrogen-methane, nitrogen-carbon dioxide, and carbon dioxide-methane binary gas systems in sandy soil, and also did simulations on the same systems using both Fick's model and the DG model. A comparison of the results of the column experiments with our simulations confirmed that there was no need to consider the dispersion in the advection-diffusion equations with the DG model when the velocity of gas was 0.05-0.4 cm/s in Toyoura sand. Furthermore, our experiments and simulations with the DG model showed that, rather than dispersion, tortuosity should be taken into account in application of the DG model to the above condition.     

Pd20Pt20Cu20Ni20P20 high-entropy alloy as a bulk metallic glass in the centimeter

A Pd₂₀Pt₂₀Cu₂₀Ni₂₀P₂₀ bulk metallic glass (BMG) with a high-entropy (HE) alloy composition and a maximum diameter of 10 mm was fabricated by fluxed water quenching. The system and composition of the Pd₂₀Pt₂₀Cu₂₀Ni₂₀P₂₀ alloy were determined from a prototype ternary Pd₄₀Ni₄₀P₂₀ BMG in accordance with two strategic alloy designs of (1) HE alloy defined by an equi-atomic alloy with five or more elements and (2) exchangeability of the constituent elements with a similar chemical nature in the periodic table. Pd₂₀Pt₂₀Cu₂₀Ni₂₀P₂₀ HE-BMG had a supercooled liquid range of 65 K and a reduced glass transition temperature of 0.71. Successful formation of Pd₂₀Pt₂₀Cu₂₀Ni₂₀P₂₀ HE-BMG is significant to develop new alloys for HE alloys and BMGs.     

Strength properties of polymer mortar panels using methyl methacrylate solution of waste expanded polystyrene as binder

The present study examines the applicability of polymer mortar panels using a methyl methacrylate (MMA) solution of waste expanded polystyrene (EPS) to develop effective recycling processes for the EPS, referring to the strength properties of a polymer-impregnated mortar panel with almost the same performance as commercial products. An MMA solution of EPS is prepared by dissolving EPS in MMA, and unreinforced and steel fiber-reinforced polymer mortars are mixed using the EPS-MMA-based solution as a liquid resin or binder. Polymer mortar panels (PMPs) using the EPS-MMA-based polymer mortars without and with steel fiber and crimped wire cloth reinforcements and steel fiber-reinforced polymer-impregnated mortar panel (PIMP) are prepared on trial, and tested for flexural behavior under four-point loading. The EPS-MMA-based PMPs are more ductile than the PIMP, and have a high load-bearing capacity. Consequently, they can replace PIMP in practical applications.     

Comparison of Fatigue Strengths of Bulk Metallic Glasses Produced by Tilt Casting and High-Pressure Casting

High fatigue strength is one of the important factors that facilitates the industrial usage of bulk metallic glasses (BMGs). Fatigue data were analyzed using the Weibull probability models for BMGs produced with different casting processes in order to study the reliability of fatigue strengths of cast glassy alloys. The fatigue data of tilt-cast and high-pressure-cast BMGs can be explained by a three-parameter Weibull cumulative distribution function (cdf) and a mixture model of two-parameter Weibull cdfs, respectively. We conclude that the cast defects, which reduce fatigue strength, should be eliminated in order to realize a high reliability of fatigue strengths.