Alternating Current Electrophoretic Deposition of Antibacterial Bioactive Glass-Chitosan Composite Coatings

Alternating current (AC) electrophoretic deposition (EPD) was used to produce multifunctional composite coatings combining bioactive glass (BG) particles and chitosan. BG particles of two different sizes were used, i.e., 2 μm and 20–80 nm in average diameter. The parameter optimization and characterization of the coatings was conducted by visual inspection and by adhesion strength tests. The optimized coatings were investigated in terms of their hydroxyapatite (HA) forming ability in simulated body fluid (SBF) for up to 21 days. Fourier transform infrared (FTIR) spectroscopy results showed the successful HA formation on the coatings after 21 days. The first investigations were conducted on planar stainless steel sheets. In addition, scaffolds made from a TiAl4V6 alloy were considered to show the feasibility of coating of three dimensional structures by EPD. Because both BG and chitosan are antibacterial materials, the antibacterial properties of the as-produced coatings were investigated using E. coli bacteria cells. It was shown that the BG particle size has a strong influence on the antibacterial properties of the coatings.     

Soft computing agents for e-Health in application to the research and control of unknown diseases

This paper presents an ontology-based holonic diagnostic system (OHDS) that combines the holonic paradigm with multi-agent system technology and ontology design, for the organization of unstructured biomedical research into structured disease information. We use ontologies as ‘brain’ for the holonic diagnostic system to enhance its ability to structure information in a meaningful way and share information fast. To integrate distributed heterogeneous knowledge available on the Web we use intelligent agents augmented by the mechanisms of the technology of fuzzy sets, which automatically structures the information in the adequate ontology template. Our vision of how this system implementation should be supported by a solid security shield that ensures the privacy and safety of medical information concludes the paper.     

Acute failure of the transplanted kidney--pathophysiology, diagnosis and prevention

Acute failure of the transplanted kidney is a major problem in the early posttransplant phase and is recognized as a major cause of graft loss. Early renal transplant dysfunction is mainly due to ischemic damage (acute tubular necrosis), rejection, infection, and cyclosporin A toxicity. Less common causes include bleeding, ureteral obstruction, urinary leak, venous thrombosis, and stenosis or occlusion of the renal transplant artery. Recent advances in both invasive (renal biopsy) and non-invasive (imaging and biochemical) techniques have improved specificity and sensitivity of the diagnosis of the acute renal failure. Several procedures which aim to prevent the kidney transplant failure have recently been introduced. Although they were shown to reduce the incidence of early allograft failure, their influence on the long-term graft survival remains to be proven.     

Influence of a prefilming treatment on the corrosion resistance of aluminium brass in aqueous solutions

The influence of a short-time prefilming treatment with benzimidazole-2-thiol on the corrosion resistance of Cu Zn 22Al 2 has been examined. The efficiency of the prefilming treatment has been evaluated by recording the anodic and the cathodic polarization curves in 0.1 N NaCl. Ellipsometric measurements have been carried out in order to obtain some information on the properties of the layer. Comparative data on “prefilmed” and “bare” Cu Zn 22Al2 specimens have been obtained in aqueous chloride solutions circulating in a corrosion loop and by tests in moist atmosphere containing SO₂. Galvanic corrosion testing have been carried out by using small not prefilmed areas and large prefilmed ones, simulating in this way the partial removal of the film from the metallic surface. The results suggest that a metal-inhibitor film forms on Al-brass, which mainly affects the cathodic reaction rate. Furthermore, the tests clearly indicate that the effect of benzimidazole-2-thiol is strongly influenced by a pre-existing oxide layer on the alloy surface. A good protection against atmospheric corrosion is reached by prefilming treatment. Corrosion loop testing indicate that prefilming does not hinder the formation of protective corrosion products on the surface of the alloy in flowing aqueous solutions.     

Distributed Computation Multi-agent System

This article addresses a formal model of a distributed computation multi-agent system. This model has evolved from the experimental research on using multi-agent systems as a ground for developing fuzzy cognitive maps. The main paper contribution is a distributed computation multi-agent system definition and mathematical formalization based on automata theory. This mathematical formalization is tested by developing distributed computation multi-agent systems for fuzzy cognitive maps and artificial neural networks – two typical distributed computation systems. Fuzzy cognitive maps are distributed computation systems used for qualitative modeling and behavior simulation, while artificial neural networks are used for modeling and simulating complex systems by creating a non-linear statistical data model. An artificial neural network encapsulates in its structure data patterns that are hidden in the data used to create the network. Both of these systems are well suited for formal model testing. We have used evolutionary incremental development as an agent design method which has shown to be a good approach to develop multi-agent systems according to the formal model of a distributed computation multi-agent system.     

Player behavior and traffic characterization for MMORPGs: a survey

Massively Multiplayer Online Role-Playing Games (MMORPGs) are one of the most exciting and most rapidly expanding genres of online games. This survey presents state-of-the-art and current research efforts in measuring, characterizing, and modeling the player behavior and the network traffic, as well as the relationships between them. We also tabulate the measurement, modeling and analysis results regarding network traffic and player behavior found in literature, with key information regarding each dataset. Finally, we list currently confirmed claims and open research questions in the area of MMORPGs.     

Biofuel developments in Mozambique. Update and analysis of policy,potential and reality

Climate change, rising oil prices and concerns about future energy supplies have contributed to a growing interest in using biomass for energy purposes. Several studies have highlighted the biophysical potential of biofuel production on the African continent, and analysts see Mozambique as one of the most promising African countries. Favorable growing conditions and the availability of land, water and labor are mentioned as major drivers behind this potential. Moreover, the potential of biofuel production to generate socio-economic benefits is reflected in the government’s policy objectives for the development of the sector, such as reducing fuel import dependency and creating rural employment. This article provides an overview of biofuel developments in Mozambique and explores to what extent reality matches the suggested potential in the country.     

Multilayers of Ge nanocrystals embedded in Al2O3 matrix: Structural and electrical studies

In this paper, Ge/Al₂O₃ multilayer systems were grown by pulsed laser ablation. The grown samples were annealed at 900 °C to promote the formation of Ge nanocrystals. Rutherford backscattering spectroscopy and transmission electron microscopy confirmed the presence of a multilayer system. Grazing incidence small angles X-ray scattering technique demonstrates the formation of Ge nanoclusters formed between alumina layers. Room temperature I-V measurements showed weak carrier trapping in the system. This was explained by the leakage caused by Ge diffusion through the multilayer.     

Deconvolution Combined with Digital Colocalization Analysis to Study the Spatial Distribution of Tight and Adherens Junction Proteins

The relative spatial distribution of proteins was investigated with immunofluorescent methods by confocal laser scanning microscopy and digital image restoration. For confocal data sets recorded with a voxel dimension of 50 × 50 × 150 nm noise and blur can be decreased and the resolution in the z-axis increased by applying the maximum likelihood estimation algorithm of the Huygens software. This approach was successfully applied to the study of tight and adherens junctions in relation to the actin cytoskeleton in Madin Darby Canine Kidney cells. Colocalization analysis was done for pairs of probes using a histogram-based method. F-actin, occludin, zonula occludens 1, and E-cadherin were included in the study. Double-labeled preparations were used. The combination of deconvolution with the colocalization of confocal data sets offers a powerful tool to investigate the spatial arrangement of proteins.