Deep neural network-based fusion model for emotion recognition using visual data

The Journal of Supercomputing - In this study, we present a fusion model for emotion recognition based on visual data. The proposed model uses video information as its input and generates emotion...     

Effect of calcinations of starting powder on mechanical properties of hydroxyapatite–alumina bioceramic composite

The effect of calcinations of starting powder on the mechanical properties of hydroxyapatite (HA)-based bioceramic composite was investigated. The calcinations of HA powder in air at 900 °C increased the crystallinity as well as the size of the powder. Ball milling after the calcinations was effective in eliminating large agglomerates in the powder. When the powder was mixed with reinforcing Al₂O₃ powder, the mixture became fine and homogeneous. The flexural strength of HA–Al₂O₃ composite was increased by the calcinations processes at all the Al₂O₃ concentration. However, the fracture toughness was not much influenced by the calcinations. These results lead to the conclusion that the calcinations process effectively reduced the critical flaw size in the body by removing the agglomerates in the HA powder.     

Calcium Phosphate Bioceramics with Various Porosities and Dissolution Rates

Porous bioceramics, such as hydroxyapatite (HA), tricalcium phosphate (TCP), and biphasic HA/TCP, were fabricated using the polyurethane sponge technique. The porosity of the ceramics was controlled by a multiple coating of the porous body. When a porous body was produced by a single coating, the porosity was ∼90%, and the pores were completely interconnected. When the sintered body was coated five times after the porous network had been made, the porosity decreased to 65%. As the porosity decreased, the strength increased exponentially. The TCP exhibited the highest dissolution rate in a Ringer's solution, and the HA had the lowest rate. The biphasic HA/TCP showed an intermediate dissolution rate.     

PMMA基底含氢非晶碳膜的结构和摩擦学性能

分别用磁控溅射和等离子体增强化学气相沉积方法在PMMA基底上沉积硅膜和含氢非晶碳(a-C:H)膜.用氩离子溅射硅靶制备硅膜,以甲烷和氢气为反应气体在不同自偏压下制备非晶碳膜.分别用原子力显微镜、X射线光电子能谱和紫外拉曼光谱表征薄膜的形貌和结构,并分别用纳米压痕仪和栓盘摩擦磨损试验机测试其机械和摩擦学性能.结果表明,沉积碳膜的PMMA基底呈现出高硬度、低摩擦系数和低磨损率的特性.碳膜的显微结构、机械和摩擦学特性均显著依赖薄膜沉积过程中使用的自偏压,其摩擦系数和磨损率与其硬度和sp3含量密切相关.     

Strength and fatigue properties of three-step sintered dense nanocrystal hydroxyapatite bioceramics

Dense hydroxyapatite (HA) ceramic is a promising material for hard tissue repair due to its unique physical properties and biologic properties. However, the brittleness and low compressive strength of traditional HA ceramics limited their applications, because previous sintering methods produced HA ceramics with crystal sizes greater than nanometer range. In this study, nano-sized HA powder was employed to fabricate dense nanocrystal HA ceramic by high pressure molding, and followed by a three-step sintering process. The phase composition, microstructure, crystal dimension and crystal shape of the sintered ceramic were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties of the HA ceramic were tested, and cytocompatibility was evaluated. The phase of the sintered ceramic was pure HA, and the crystal size was about 200 nm. The compressive strength and elastic modulus of the HA ceramic were comparable to human cortical bone, especially the good fatigue strength overcame brittleness of traditional sintered HA ceramics. Cell attachment experiment also demonstrated that the ceramics had a good cytocompatibility.     

Study of hydrogen production in light assisted microbial electrolysis cell operated with dye sensitized solar cell

Hydrogen production with light as an additional energy source in a microbial electrolysis cell (MEC) is described. A ruthenium-dye (N719) sensitized solar cell with an open circuit potential (V_oc) of 602 mV was connected to the MEC. Hydrogen production was carried out by irradiating the DSSC connected across the MEC with a light intensity of 40 mW/cm² and also with natural sunlight. The DSSC was stable during various batch experiments. The acetate conversion efficiency and the coulombic efficiency based on the average of first two batches were 30.5 ± 2.5% and 40 ± 2% respectively. The cathodic recovery efficiency ranged from 72% to 86% during repeated batch experiments with an average of 78 ± 2.5%.     

Composition and Crystallization of Hydroxyapatite Coating Layer Formed by Electron Beam Deposition

To improve the biocompatibility of Ti-based metal implants, a hydroxyapatite (HA) coating layer was formed on the surface by electron-beam deposition. The dissolution rate of the coating layer was strongly dependent on the layer's calcium/phosphorus (Ca/P) ratio. Layers with a Ca/P ratio close to that of crystalline HA (Ca/P = 1.67) showed good stability in a physiologic saline solution. When the layer was crystallized by heat treatment in air at temperatures between 400° and 500°C, the stability was enhanced further while maintaining good interfacial bonding strength with the substrate. Preliminary in vivo tests on rabbits indicated that heat treatment and the resultant enhancement in stability are beneficial for bone attachment to the implants.     

Poly(acrylic acid)-regulated Synthesis of Rod-Like Calcium Carbonate Nanoparticles for Inducing the Osteogenic Differentiation of MC3T3-E1 Cells

Calcium carbonate, especially with nanostructure, has been considered as a good candidate material for bone regeneration due to its excellent biodegradability and osteoconductivity. In this study, rod-like calcium carbonate nanoparticles (Rod-CC NPs) with desired water dispersibility were achieved with the regulation of poly (acrylic acid). Characterization results revealed that the Rod-CC NPs had an average length of 240 nm, a width of 90 nm with an average aspect ratio of 2.60 and a negative ζ-potential of −22.25 ± 0.35 mV. The degradation study illustrated the nanoparticles degraded 23% at pH 7.4 and 45% at pH 5.6 in phosphate-buffered saline (PBS) solution within three months. When cultured with MC3T3-E1 cells, the Rod-CC NPs exhibited a positive effect on the proliferation of osteoblast cells. Alkaline phosphatase (ALP) activity assays together with the osteocalcin (OCN) and bone sialoprotein (BSP) expression observations demonstrated the nanoparticles could induce the differentiation of MC3T3-E1 cells. Our study developed well-dispersed rod-like calcium carbonate nanoparticles which have great potential to be used in bone regeneration.     

Cancer cell proliferation controlled by surface chemistry in its microenvironment

Hepatoma cells (Hepg2s) as typical cancer cells cultured on hydroxyl (-OH) and methyl (-CH₃) group surfaces were shown to exhibit different proliferation and morphological changes. Hepg2s cells on -OH surfaces grew much more rapidly than those on -CH₃ surfaces. Hepg2s cells on -OH surfaces had the larger contact area and the more flattened morphology, while those on -CH₃ surfaces exhibited the smaller contact area and the more rounded morphology. After 7 days of culture, the migration of Hepg2s cells into clusters on the -CH₃ surfaces behaved significantly slower than that on the -OH surfaces. These chemically modified surfaces exhibited regulation of Hepg2s cells on proliferation, adhesion, and migration, providing a potential treatment of liver cancer.