Investigation of Bed Joint Reinforcement Influence on Mechanical Properties of Masonry under Compression

The results of investigations of compressed reinforced masonry walls subjected to axial compression are presented. Tests were carried out using specimens made of clay bricks and cement-lime mortar. As reinforcement, smooth and spiral twisted longitudinal rods, two types of structural wire mesh and truss type reinforcement were used. Two percentages of bed joint reinforcement, about 0.1% and 0.05% were applied. For each type of reinforcement, three masonry walls were tested. Additionally, nine unreinforced models were also tested. The main aim of the investigations presented is to determine the effect of different types of reinforcement on the load capacity and failure. Measurement of the strains of reinforcing bars permitted the recording of the strain level at the moment of crack appearance and also at the moment of failure.     

Fast averaging peer group filter for the impulsive noise removal in color images

In the paper, a new approach to the impulsive noise removal in color images is presented. The new filtering design is based on the peer group concept, which determines the membership of a central pixel of the filtering window to its local neighborhood, in terms of the number of close pixels. Two pixels are declared as close if their distance in a given color space does not exceed a predefined threshold value. A pixel is treated as not corrupted by the impulsive noise process, if its peer group consists of at least two close pixels, otherwise this pixel is replaced by a weighted average of uncorrupted samples from the local neighborhood. The peer group size assigned to each pixel is used for the averaging operation, so that pixels which have many peers are taken with higher weight. The new filtering design proved to restore efficiently color images corrupted by even strong impulsive noise, while preserving tiny image details. The beneficial property of the proposed filter is its very low computational complexity, which allows its application in real-time image processing tasks.     

Chalcones Enhance TRAIL-Induced Apoptosis in Prostate Cancer Cells

Chalcones exhibit chemopreventive and antitumor effects. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a naturally occurring anticancer agent that induces apoptosis in cancer cells and is not toxic to normal cells. We examined the cytotoxic and apoptotic effect of five chalcones in combination with TRAIL on prostate cancer cells. The cytotoxicity was evaluated by the MTT and LDH assays. The apoptosis was determined using flow cytometry with annexin V-FITC. Our study showed that all five tested chalcones: chalcone, licochalcone-A, isobavachalcone, xanthohumol, butein markedly augmented TRAIL-mediated apoptosis and cytotoxicity in prostate cancer cells and confirmed the significant role of chalcones in chemoprevention of prostate cancer.     

Mechanical and Tribological Properties of HVOF-Sprayed (Cr<Subscript>3</Subscript>C<Subscript>2</Subscript>-NiCr+Ni) Composite Coating on Ductile Cast Iron

The aim of the investigations was to compare the microstructure, mechanical, and wear properties of Cr₃C₂-NiCr+Ni and Cr₃C₂-NiCr coatings deposited by HVOF technique (the high-velocity oxygen fuel spray process) on ductile cast iron. The effect of nickel particles added to the chromium carbide coating on mechanical and wear behavior in the system of Cr ₃ C ₂ -NiCr+Ni/ductile cast iron was analyzed in order to improve the lifetime of coated materials. The structure with particular emphasis of characteristic of the interface in the system of composite coating (Cr ₃ C ₂ -NiCr+Ni)/ductile cast iron was studied using the optical, scanning, and transmission electron microscopes, as well as the analysis of chemical and phase composition in microareas. Experimental results show that HVOF-sprayed Cr₃C₂-NiCr+Ni composite coating exhibits low porosity, high hardness, dense structure with large, partially molten Ni particles and very fine Cr₃C₂ and Cr₇C₃ particles embedded in NiCr alloy matrix, coming to the size of nanocrystalline. The results were discussed in reference to examination of bending strength considering cracking and delamination in the system of composite coating (Cr ₃ C ₂ -NiCr+Ni)/ductile cast iron as well as hardness and wear resistance of the coating. The composite structure of the coating provides the relatively good plasticity of the coating, which in turn has a positive effect on the adhesion of coating to the substrate and cohesion of the composite coating (Cr₃C₂-NiCr+Ni) in wear conditions.     

Virtual screening and experimental verification to identify potential inhibitors of the ErmC methyltransferase responsible for bacterial resistance against macrolide antibiotics

Methyltransferases from the Erm family catalyze S-adenosyl-L-methionine-dependent modification of a specific adenine residue in bacterial 23S rRNA, thereby conferring resistance to clinically important macrolide, lincosamide, and streptogramin B antibiotics. Thus far, no inhibitors of these enzymes have been identified or designed that would effectively abolish the resistance in vivo. We used the crystal structure of ErmC' methyltransferase as a target for structure-based virtual screening of a database composed of 58,679 lead-like compounds. Among 77 compounds selected for experimental validation (63 predicted to bind to the catalytic pocket and 14 compounds predicted to bind to the putative RNA binding site), we found several novel inhibitors that decrease the minimal inhibitory concentration of a macrolide antibiotic erythromycin toward an Escherichia coli strain that constitutively expresses ErmC'. Eight of them have IC(50) values in the micromolar range. Analysis of docking models of the identified inhibitors suggests a novel strategy to develop potent and clinically useful inhibitors.     

Experiment Dashboard for Monitoring Computing Activities of the LHC Virtual Organizations

The Large Hadron Collider (LHC) is preparing for data taking at the end of 2009. The Worldwide LHC Computing Grid (WLCG) provides data storage and computational resources for the high energy physics community. Operating the heterogeneous WLCG infrastructure, which integrates 140 computing centers in 33 countries all over the world, is a complicated task. Reliable monitoring is one of the crucial components of the WLCG for providing the functionality and performance that is required by the LHC experiments. The Experiment Dashboard system provides monitoring of the WLCG infrastructure from the perspective of the LHC experiments and covers the complete range of their computing activities. This work describes the architecture of the Experiment Dashboard system and its main monitoring applications and summarizes current experiences by the LHC experiments, in particular during service challenges performed on the WLCG over the last years.     

Mechanism of cellular uptake of genotoxic silica nanoparticles

ABSTRACT: Mechanisms for cellular uptake of nanoparticles have important implications for nanoparticulate drug delivery and toxicity. We have explored the mechanism of uptake of amorphous silica nanoparticles of 14 nm diameter, which agglomerate in culture medium to hydrodynamic diameters around 500 nm. In HT29, HaCat and A549 cells, cytotoxicity was observed at nanoparticle concentrations 1 mug/ml, but DNA damage was evident at 0.1 mug/ml and above. Transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectroscopy confirmed entry of the silica particles into A549 cells exposed to 10 mug/ml of nanoparticles. The particles were observed in the cytoplasm but not within membrane bound vesicles or in the nucleus. TEM of cells exposed to nanoparticles at 4 C for 30 minutes showed particles enter cells when activity is low, suggesting a passive mode of entry. Plasma lipid membrane models identified physical interactions between the membrane and the silica NPs. Quartz crystal microbalance experiments on tethered bilayer lipid membrane systems show that the nanoparticles strongly bind to lipid membranes, forming an adherent monolayer on the membrane. Leakage assays on large unilamellar vesicles (400 nm diameter) indicate that binding of the silica NPs transiently disrupts the vesicles which rapidly self-seal. We suggest that an adhesive interaction between silica nanoparticles and lipid membranes could cause passive cellular uptake of the particles.     

Flattening tuples in an SSA intermediate representation

For functional programs, unboxing aggregate data structures such as tuples removes memory indirections and frees dead components of the decoupled structures. To explore the consequences of such optimizations in a whole-program compiler, this paper presents a tuple flattening transformation and a framework that allows the formal study and comparison of different flattening schemes. We present our transformation over functional SSA, a simply-typed, monomorphic language and show that the transformation is type-safe. The flattening algorithm defined by our transformation has been incorporated into MLton, a whole-program, optimizing compiler for SML. Experimental results indicate that aggressive tuple flattening can lead to substantial improvements in runtime performance, a reduction in code size, and a decrease in total allocation without a significant increase in compilation time.     

Phenolic acid concentrations in organically and conventionally cultivated spring and winter wheat

BACKGROUND: Organic crops are often thought to contain more phenolic secondary metabolites than conventional ones. This study evaluated the influence of organic and conventional farming on concentrations of phenolic acids in spring and winter wheat cultivars. RESULTS: Five phenolic acids were identified: ferulic, sinapic, p‐coumaric, vanillic and p‐hydroxybenzoic acid. Ferulic acid was the main phenolic acid in the grain of all tested wheat varieties. Significant differences among the examined cultivars in concentration of particular compounds were observed. Concentrations of phenolic acids varied significantly in organic and conventional wheat. Levels of ferulic and p‐coumaric acids, as well as the total phenolic acid content were higher in organic crops. Concentrations of sinapic acid in spring wheat, as well as vanillic and p‐hydroxybenzoic acid levels in both types of wheat were significantly higher in conventional grains. The 1000 kernel weight (TKW) of spring and winter wheat was significantly lower in organic crops. CONCLUSION: Organically produced spring and winter wheat had significantly higher concentrations of ferulic and p‐coumaric acid as well as the total phenolic acid content than conventional wheat, though the differences in the levels of phenolics were not large. However, these differences are probably caused mainly by smaller size of organic wheat kernels (lower TKW). Copyright © 2011 Society of Chemical Industry