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Evaluates the Schottky barrier heights and conduction-band offsets of In[sub 1-x]Ga[sub x]As[sub 1-y]P[sub y] epilayers. Growth of epilayers on gallium arsenide substrates; Dependence of Schottky barrier heights on the composition of the substrate material; Correlation between metal-semiconductor and semiconductor-semiconductor heterointerfaces.

Titanium dioxide nanoparticles (TiO2-NPs) are used to improve the aesthetic of toothpaste. While TiO2-NPs have been used safely in toothpaste products for a long time, there haven't been studies to determine whether absorption of TiO2-NPs by the mucous membranes in the mouth induces pathogenic conditions. Here, we assessed whether TiO2-NPs induce cyclooxygenase-2 (COX-2) and investigated the molecular mechanisms underlying the pro-inflammatory effect of TiO2-NPs on human periodontal ligament (PDL) cells. Treatment of PDL cells with TiO2-NPs led to induction of both COX-2 mRNA and protein expression. TiO2-NPs stimulated the nuclear translocation of nuclear factor-kappaB (NF-κB) as well as its DNA binding by inducing phosphorylation and subsequent degradation of the inhibitory protein IκBa in PDL cells. TiO2-NPs treatment resulted in rapid activation of extracellular signal- regulated kinase (ERK)1/2 and Akt, which could be upstream of NF-κB. Treatment of PDL cells with both the MEK1/2 inhibitor U0126 and the PI3K inhibitor LY294002 strongly attenuated TiO2-NPs-induced activation of NF-κB, and also the expression of COX-2. PDL cells treated with TiO2-NPs exhibited increased accumulation of intracellular reactive oxygen species (ROS). Pretreatment of cells with ROS scavenger N-acetyl cysteine (NAC) abrogated the stimulatory effect of TiO2-NPs on p65, p50, and COX-2 expression. In conclusion, ROS, concomitantly overproduced by TiO2-NPs, induce COX-2 expression through activation of NF-κB signaling, which may contribute to the inflammatory effect of PDL cells. [ABSTRACT FROM AUTHOR]

We demonstrate a highly sensitive and flexible bending strain sensor using tin-doped indium oxide (ITO) nanoparticles (NPs) assembled in line patterns on flexible substrates. By utilizing transparent ITO NPs without any surface modifications, we could produce strain sensors with adjustable gauge factors and optical transparency. We were able to control the dimensional and electrical properties of the sensors, such as channel height and resistance, by controlling the NP assembly speed. Furthermore, we were able to generate controlled gauge factor with values ranging from 18 to 157, which are higher than previous cases using metallic Cr NPs and Au NPs. The alignment of the ITO NPs in parallel lines resulted in low crosstalk between the transverse and longitudinal bending directions. Finally, our sensor showed high optical transmittance, up to ∼93% at 500 nm wavelength, which is desirable for flexible electronic applications. [ABSTRACT FROM AUTHOR]

Pirimiphos-methyl (O-2-diethylamino-6-methylpyrimidin-4-yl O,O-dimethyl phosphorothioate: POM) is widely used organophosphorous(OP) insecticide as a grain protectant to control insects during storage. This study was carried out to assess the immunologic effects of POM in Balb/c mice after 28-day oral exposure. Three dose levels of POM (10, 60, or 120 mg/kg/day) were administered orally to mice for 4 weeks. At autopsy after 28-day exposure, there were significant decreases in relative spleen weight and splenic cellularity found at 120 mg POM, but body weight, relative thymic weight, thymic cellularity, and splenic and thymic subsets were not affected. T cell proliferation response induced by Con A was significantly decreased at all dosages though no statistical differences were observed in splenic B cell proliferation. Significant increases in the production of cytokines (IL-2, IL-4, IL-6, IFN- γ, and IL-10) were evident on the whole, but the increase in production of inflammatory cytokines overwhelmed that of the TH1 cell suppressive cytokine (IL-10). The relative levels of three types of autoantibodies, anti-dsDNA, anti-histone, and antinuclear antibody (ANA) were dose-dependently decreased in serum. Oral exposure to POM induced a significant decrease in Immunoglobulin M production capability in Balb/c mice. This decrease in antibody production capability may result from disturbances in cytokine balance produced by splenic immune cells. These results show that POM may induce allergic responses by relatively enhancing TH2 development and additionally contribute to chronic inflammation by attracting macrophage by IFN-γ. [ABSTRACT FROM AUTHOR]

We report three-dimensionally assembled nanoparticle structures inducing multiple plasmon resonances for broadband light harvesting in nanocrystalline silicon (nc-Si:H) thin-film solar cells. A three-dimensional multiscale (3DM) assembly of nanoparticles generated using a multi-pin spark discharge method has been accomplished over a large area under atmospheric conditions via ion-assisted aerosol lithography. The multiscale features of the sophisticated 3DM structures exhibit surface plasmon resonances at multiple frequencies, which increase light scattering and absorption efficiency over a wide spectral range from 350–1100 nm. The multiple plasmon resonances, together with the antireflection functionality arising from the conformally deposited top surface of the 3D solar cell, lead to a 22% and an 11% improvement in power conversion efficiency of the nc-Si:H thin-film solar cells compared to flat cells and cells employing nanoparticle clusters, respectively. Finite-difference time-domain simulations were also carried out to confirm that the improved device performance mainly originates from the multiple plasmon resonances generated from three-dimensionally assembled nanoparticle structures. [ABSTRACT FROM AUTHOR]