New fabrication approach to ZnO multiple nanofiber sensors

In the presented work, ZnO nanofiber sensor structures designed and fabricated using a standard microelectronic device technology were studied. The structures in the configuration of a resistor with chemically active ZnO multiple nanofibers deposited by electrospinning method were prepared. Investigation of inclusion in the process reactive- ly sputtered AlN insulating film to improve the robustness of the nanofibres on the substrate was undertaken. Selective wet chemical etching of AlN film using photoresist developers and a photoresist mask to define the sensor active area was studied. The Ti/Au ohmic contacts were fabricated using the lift-off photolithography process. To- pography of the sensor structure details was investigated using AFM. Electrical charac- terization by means of I-V measurements was made. Sensitivity to the physiologically relevant concentration of Bovine Serum Albumin in water solution was shown. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2058

Psoriasis vulgaris and digestive system disorders: is there a linkage?

Psoriasis is well-known immune-mediated skin disease often associated with co-morbidities, including dyslipidaemia and obesity. Few reports imply that the disease might be also related to pathology of mucosal surfaces, especially that of the digestive system. The authors present a case of psoriasis and concurrent digestive system abnormalities, and review the literature regarding the topic. A 40-year-old man suffered from an exacerbation of exudative psoriasis for about 6 months. Topical antipsoriatics proved ineffective and the disease gradually progressed to a severe disseminated form. Subsequent detailed examinations revealed persistent gastroduodenitis due to H. pylori infection, pancreatic dysfunction and fatty change of the liver, although the patient denied any gastrointestinal symptoms. As a result appropriate treatment of the diagnosed digestive system disorders was added to topical antipsoriatic therapy. Within 2 weeks of treatment clinical symptoms and laboratory signs showed a marked trend to normalisation. The presented medical history seems to suggest that there may be some kind of interplay between psoriasis and digestive system disorders

Wigner transform and pseudodifferential operators on symmetric spaces of non-compact type

We obtain a general expression for a Wigner transform (Wigner function) on symmetric spaces of non-compact type and study the Weyl calculus of pseudodifferential operators on them

Formation and tribology of fucoidan/chitosan polyelectrolyte multilayers on PDMS substrates

Polysaccharide polyelectrolyte multilayers (PEMs) based on fucoidan and chitosan were formed by Layer-by-Layer (LbL) assembly on polydimethylsiloxane (PDMS) substrates. The surface and aqueous lubrication properties of the PEM films are evaluated for two types of fucoidan extracted from separate seaweed species (Fucus vesiculosus – FV and Undaria pinnatifida – UP). Zeta potential and atomic force microscopy (AFM) imaging reveal that the PEM layers are formed with consistent charge reversal as each polysaccharide layer is adsorbed to the PDMS substrate, and that there is an associated increase in thickness of the multilayer. The multilayers containing FV fucoidan are found to be thicker than those containing UP fucoidan. Soft tribology measurements using matching PDMS tribo-pairs are used to show that the films are robust under rolling/sliding contacts and effective under aqueous lubricating conditions. The friction in the boundary lubrication regime is substantially decreased (relative to native hydrophobic PDMS) by the presence of the multilayers, with some dependence on whether fucoidan or chitosan is in the outer layer (5 or 5.5 bilayers) for FV fucoidan. The lowest friction coefficient is obtained for the multilayer with the thickest (and likely most hydrated) coating – the (FV/chitosan) 5.5 bilayer system. The results suggest that PEMs involving naturally derived polysaccharides such as fucoidan, which has notable antimicrobial properties and is resistant to enzymatic degradation, may provide opportunities in surface coating design in biomaterials applications for friction reduction

Automatic Analysis of Composite Physical Signals Using Non-Negative Factorization and Information Criterion

In time-resolved spectroscopy, composite signal sequences representing energy transfer in fluorescence materials are measured, and the physical characteristics of the materials are analyzed. Each signal sequence is represented by a sum of non-negative signal components, which are expressed by model functions. For analyzing the physical characteristics of a measured signal sequence, the parameters of the model functions are estimated. Furthermore, in order to quantitatively analyze real measurement data and to reduce the risk of improper decisions, it is necessary to obtain the statistical characteristics from several sequences rather than just a single sequence. In the present paper, we propose an automatic method by which to analyze composite signals using non-negative factorization and an information criterion. The proposed method decomposes the composite signal sequences using non-negative factorization subjected to parametric base functions. The number of components (i.e., rank) is also estimated using Akaike's information criterion. Experiments using simulated and real data reveal that the proposed method automatically estimates the acceptable ranks and parameters

The first microsolvation step for furans : new experiments and benchmarking strategies

The site-specific first microsolvation step of furan and some of its derivatives with methanol is explored to benchmark the ability of quantum-chemical methods to describe the structure, energetics, and vibrational spectrum at low temperature. Infrared and microwave spectra in supersonic jet expansions are used to quantify the docking preference and some relevant quantum states of the model complexes. Microwave spectroscopy strictly rules out in-plane docking of methanol as opposed to the top coordination of the aromatic ring. Contrasting comparison strategies, which emphasize either the experimental or the theoretical input, are explored. Within the harmonic approximation, only a few composite computational approaches are able to achieve a satisfactory performance. Deuteration experiments suggest that the harmonic treatment itself is largely justified for the zero-point energy, likely and by design due to the systematic cancellation of important anharmonic contributions between the docking variants. Therefore, discrepancies between experiment and theory for the isomer abundance are tentatively assigned to electronic structure deficiencies, but uncertainties remain on the nuclear dynamics side. Attempts to include anharmonic contributions indicate that for systems of this size, a uniform treatment of anharmonicity with systematically improved performance is not yet in sight

Capric Acid Secreted by S. boulardii Inhibits C. albicans Filamentous Growth, Adhesion and Biofilm Formation

Candidiasis are life-threatening systemic fungal diseases, especially of gastro intestinal track, skin and mucous membranes lining various body cavities like the nostrils, the mouth, the lips, the eyelids, the ears or the genital area. Due to increasing resistance of candidiasis to existing drugs, it is very important to look for new strategies helping the treatment of such fungal diseases. One promising strategy is the use of the probiotic microorganisms, which when administered in adequate amounts confer a health benefit. Such a probiotic microorganism is yeast Saccharomyces boulardii, a close relative of baker yeast. Saccharomyces boulardii cells and their extract affect the virulence factors of the important human fungal pathogen C. albicans, its hyphae formation, adhesion and biofilm development. Extract prepared from S. boulardii culture filtrate was fractionated and GC-MS analysis showed that the active fraction contained, apart from 2-phenylethanol, caproic, caprylic and capric acid whose presence was confirmed by ESI-MS analysis. Biological activity was tested on C. albicans using extract and pure identified compounds. Our study demonstrated that this probiotic yeast secretes into the medium active compounds reducing candidal virulence factors. The chief compound inhibiting filamentous C. albicans growth comparably to S. boulardii extract was capric acid, which is thus responsible for inhibition of hyphae formation. It also reduced candidal adhesion and biofilm formation, though three times less than the extract, which thus contains other factors suppressing C. albicans adherence. The expression profile of selected genes associated with C. albicans virulence by real-time PCR showed a reduced expression of HWP1, INO1 and CSH1 genes in C. albicans cells treated with capric acid and S. boulardii extract. Hence capric acid secreted by S. boulardii is responsible for inhibition of C. albicans filamentation and partially also adhesion and biofilm formation

Sophorolipid biosurfactants: Possible uses as antibacterial and antibiofilm agent.

Biosurfactants are amphipathic, surface-active molecules of microbial origin which accumulate at interfaces reducing interfacial tension and leading to the formation of aggregated micellular structures in solution. Some biosurfactants have been reported to have antimicrobial properties, the ability to prevent adhesion and to disrupt biofilm formation. We investigated antimicrobial properties and biofilm disruption using sophorolipids at different concentrations. Growth of Gram negative Cupriavidus necator ATCC 17699 and Gram positive Bacillus subtilis BBK006 were inhibited by sophorolipids at concentrations of 5% v/v with a bactericidal effect. Sophorolipids (5% v/v) were also able to disrupt biofilms formed by single and mixed cultures of B. subtilis BBK006 and Staphylococcus aureus ATCC 9144 under static and flow conditions, as was observed by scanning electron microscopy. The results indicated that sophorolipids may be promising compounds for use in biomedical application as adjuvants to other antimicrobial against some pathogens through inhibition of growth and/or biofilm disruption