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Abstract Mesenchymal stem cell (MSC) is mechanosensitive and the respond to mechanical force is pattern specific. We previously reported that oscillatory shear stress at 0.5 ± 4 dyne/cm2 guided MSCs polarity vertical to net flow direction before apolaric stage at 30 min resulting in phosphorylation of β-catenin and inhibition of Wnt signaling. This time, we explored laminar shear stress (LS) at 0.5 dyne/cm2 polarized MSCs by guiding F-actin orientation parallel to the flow direction before apolarity at 30 min accompanied with activation of Wnt signaling. Time-dependent microarray analysis supported cell-cell junctional complex of MSCs was the major mechanosensor on MSCs to respond 0.5 dyne/cm2 LS. Three-dimensional immunofluorescence image confirmed LS promoting β-catenin nuclear localization during 15 min to 1 h with a peak at 30 min. Functional analysis of proteomic study on MSC with 30 min LS stimulation indicated that upregulation of β-catenin downstream proteins related to cardiovascular development, endothelial cell protection and angiogenesis. Conditioned medium from MSCs with 30 min LS stimulation improved the viability of human endothelial cells from oxidative damage. In conclusion, 0.5 dyne/cm2 LS on MSCs for 30 min guides MSCs lack of polarity and promotes β-catenin nuclear translocation favoring Wnt activation and paracrine cardiovascular support. [ABSTRACT FROM AUTHOR]

Abstract: We report the influence of boron doping concentration on the microstructure, electrical and optical properties of solution-processed zinc oxide (ZnO) thin films. The B doping concentration in the resultant solutions was varied from 0 to 5at%, and the pH value of each synthetic solution was adjusted to 7.0. XRD measurements, SEM observations, and SPM examinations revealed that boron doping produced ZnO thin films consisting of a fine grain structure with a flat surface morphology. Moreover, ZnO thin films doped with B raised the texture coefficient along the (002) plane. All B-doped ZnO (ZnO:B) thin films exhibited higher transparency than that of the undoped ZnO thin film in the wavelengths between 350 and 650nm. The optical band gap and Urbach energy of the ZnO:B thin films were higher than those of the undoped thin film. According to electrical transport characteristics, the 1% B-doped ZnO thin film exhibited the highest Hall mobility of 17.9cm2/Vs, the highest electron concentration of 1.2×1015 cm−3, and the lowest electrical resistivity of 2.2×102 Ωcm among all of the ZnO:B thin films. [Copyright &y& Elsevier]

Abstract: The n-type layer plays an important role in the fabrication of CuInGaSe2 solar cells in terms of solar cell efficiency and production cost. Chemical bath deposition is commonly used to prepare n-type layers. However, uniformity, coverage, and cost issues presented by the method must be solved prior to its application in mass production. A technique called shallow chemical bath deposition was employed to grow an n-type CdS layer on a 370mm×470mm glass substrate. This technique used a shallow bath for higher thermal gradients, while using a shaker to mix solution. As a result, the homogeneous nucleation was suppressed and large area uniformity could be achieved. UV–visible NIR spectrophotometry, scanning electronic microscopy, and X-ray diffraction were employed to characterize the quality of the thin film obtained. The experimental results showed that shallow chemical bath deposition could be an excellent candidate for chemical bath deposition technique. [Copyright &y& Elsevier]

Abstract: The structural and luminescence characteristics of sol–gel derived Y3Al5O12:Eu3+ (YAG:Eu3+) phosphors were investigated using synchrotron radiation. VUV-excited luminescence studies reveal that two major excitation peaks formed at 178 and 238nm are responsible for producing the characteristic red emission of Eu3+ ions. The emission characteristics of the sol–gel derived YAG:Eu3+ phosphors depend significantly on the calcination temperature and cationic ratios. The Rietveld refinement analysis and luminescence studies indicate that increasing either the calcination temperature or the aluminum ion content can result in a more symmetrical anionic environment for Eu3+ ions in the YAG host, thereby enhancing the luminescence of the synthesized phosphors. YAG:Eu3+ phosphors with reduced particle sizes and improved emission characteristics were successfully prepared in this study via controlling the calcination temperature and cationic ratios. [Copyright &y& Elsevier]

Abstract: Europium-ion doped BaMgAl10O17 phosphors were prepared via both a sol–gel route and the conventional solid-state route. The effects of various preparation conditions on the optical properties of BaMgAl10O17 based phosphors were investigated. The position of charge transfer band and emission characteristics of europium ions in Ba0.9Eu0.1MgAl10O17 are observed to be different between those prepared by the sol–gel route and those derived from the solid-state route. The sites occupied by europium ions in BaMgAl10O17 are found to depend upon the method of synthesis. The ratios of the intensity of 610nm emission (5D0→7F2) to that of 590nm emission (5D0→7F1) suggest that Eu3+ ions are located in a more asymmetric environment for the sol–gel-derived phosphors as compared to that in phosphors prepared via the solid-state route. VUV-excited emission characteristics indicate that the prepared phosphors generate intense emission at 458nm under excitation at 147nm. In addition, the luminescence intensity of the sol–gel-derived phosphors is greater than that of the solid-state-route-derived phosphors. The sol–gel method employing polymerizing agents is demonstrated to be suitable for the synthesis of phosphors used in plasma display panels. [Copyright &y& Elsevier]

Europium-ion doped Y3Al5O12 garnet nanophosphors (YAG:Eu3+) with wide ranging size tunability (40–150 nm) have been prepared via a sol–gel pyrolysis method employing a fuel system that combined urea and polyvinyl alcohol (PVA). Well dispersed nanoparticles were prepared at 1000 °C. This temperature is lower than that required for synthesizing YAG:Eu3+ via the solid-state reaction route. The particle size and morphology of the synthesized powders are found to have critical dependence on the oxidizer (metallic nitrates) to fuel ratio. The importance of using an organic polymeric dispersion matrix to obtain well dispersed YAG:Eu3+ nanoparticles has been demonstrated. The photoluminescene properties of the prepared YAG:Eu3+ phosphors are profoundly dependent on the preparation conditions. The emission intensity of well dispersed YAG:Eu3+ nanoparticles is found to be much stronger than that of the bulk sample. The excitation spectrum of well dispersed nanoparticles shows an extension of the excitation peak in the high-energy region. These unique properties of YAG:Eu3+ nanoparticles can be rationalized by considering numerous surface states due to the large surface area to volume ratio of the nanoparticles. In addition, using the hypersensitive 5D0→7F2 transition of Eu3+ as a local probe, the role of surface states that modify the optical properties of YAG:Eu3+ nanophosphors has also been illustrated. [Copyright &y& Elsevier]

Nano-sized Eu3+-activated yttrium aluminum garnet (Y3Al5O12, YAG) phosphors were prepared via a simple sol–gel process at as low a temperature as 900 °C. In comparison with the conventional solid-state reaction process, this sol–gel process not only reduced the temperature required for synthesizing YAG:Eu3+ powders, but also decreased their particle size to the nanometer range. In the sol–gel process, citric acid and ethylene glycol formed numerous tiny enclosures that trapped the constituent cations, leading to a reduction of the interdiffusion length and an enhancement of the reactivity of the precursors. The photoluminescence intensity of the sol–gel-prepared YAG:Eu3+ phosphors was markedly greater than that of the samples derived from the solid-state reaction. This is attributed to the increased crystallinity and improved compositional homogeneity in the sol–gel-derived powders. The photoluminescence characteristics of YAG:Eu3+ phosphors were demonstrated to substantially depend on their morphology and particle size. [Copyright &y& Elsevier]

Amyloid aggregates of proteins are one of the most abundant and important naturally occurring self-associated assemblies. Formation of poly/peptide amyloid aggregates is also associated with the widely spread diseases, so called amyloidosis, which include Alzheimer’s disease, diabetes mellitus and lysozyme amyloidosis. These disorders are still incurable and novel therapeutical approaches are focused on using small molecules for inhibition of amyloid aggregation. We have observed effect of three structurally distinct groups of tacrine/acridone – coumarin heterodimers on hen egg white (HEW) lysozyme fibrillization in vitro . The ability of heterodimers to interfere with lysozyme amyloid aggregation was examined using Thioflavin T fluorescence assay, atomic force microscopy and docking method. The obtained data suggest that inhibitory effect of heterodimers on lysozyme fibrillization depends on their composition. We have shown that tacrine-coumarin heterodimers with alkylenediamine linker are the most effective inhibitors of lysozyme fibrillization. The inhibitory activities were quantified through IC 50 values; the most potent heterodimers interfere with lysozyme aggregation in the scale of micromolar concentrations (19.2 μM–105.4 μM). The molecular docking showed that the modes of possible interactions involved in the binding are mainly hydrophobic interactions, hydrogen bonding and van der Waals interactions. Studied heterodimers had none or weak cytotoxic effect on human neuroblastoma cells. The obtained results can be helpful for the design and development of new therapeutics for amyloid-related diseases. [ABSTRACT FROM AUTHOR]

This paper explores and compares the characteristics of eight different kinds of Cu(In, Ga)Se 2 (CIGS) solar cells. Through the technique of chemical bath deposition (CBD), single- (i-ZnO) and double-layer (ZnS/CdS) CIGS cells were prepared and evaluated. The results of this research signify the potential of high-performance CIGS cells for photovoltaic (PV) industrial applications. This study focused on the growth-dependency and optical properties of ZnS/CdS-buffer stacked thin films, which were prepared through the CBD process. The best sample developed from this process consisted of a double-layer buffer and no i-ZnO layer. This sample yielded a conversion efficiency (η) of 9.23% and a short-circuit current density (J SC ) of 26.72 mA/cm 2 . The performance of this sample was about 25% (absolute gain) better than that of the standard CdS cells. Furthermore, the average quantum efficiency in the short wavelength range (350–500 nm) for two of the ZnS/CdS buffer structures was 6.8% better than that of a single-layer CdS cell. This improvement can be attributed to the anti-reflective effect of the ZnS/CdS buffer structure, which increases the light-intensity incident on the main absorption layer. In addition, the ZnS/CdS-buffer layer not only eliminates the need for an i-ZnO layer but also reduces the usage of toxic Cd. The procedures to develop these flexible CIGS cells containing a ZnS/CdS buffer structure are simple, efficient, and reliable. These eco-friendly cells could be effectively applied to mass production for commercial PV applications. [ABSTRACT FROM AUTHOR]

Lung fibrosis is a poor prognostic factor for pulmonary adenocarcinoma, and the effect of a rigid microenvironment on cancer behavior is unclear. We cultured A549 cells on matrices of 0.2, 2, and 25 kPa to mimic the rigidities of normal lung parenchyma, progressive fibrotic change, and lung fibrosis, respectively. Lung tissue from patients with pulmonary adenocarcinoma was used to confirm the in vitro findings. Increased matrix rigidity promoted cell proliferation and upregulated the epidermal growth factor receptor (EGFR), hepatocyte growth factor receptor (c-Met), and Snail expression in A549 cells. A549 cells became more resistant to the EGFR inhibitor (Erlotinib) and c-Met inhibitor (PHA-665752) when matrix rigidity increased; however, a high concentration of PHA-665752 reversed the rigidity-induced morphological pleomorphism. In human lung tissue, expression of type I collagen was more consistent with clinical fibrosis than the expression of alpha-smooth muscle antibody was. c-Met- and Snail-expressing tumor cells, rather than EGFR-experssing cells, were localized with lung parenchyma rich in type I collagen. Our findings suggest that c-Met causes the rigidity-induced biophysical reaction in pulmonary adenocarcinoma. Treatment targeting both EGFR and c-Met should be considered for patients with lung fibrosis and who are abundant type I collagen expression in the tumor mass. [ABSTRACT FROM AUTHOR]