Drug resistance of Helicobacter pylori strains isolated from patients with inflammation of stomach mucous membrane and peptic ulcer of stomach and duodenum

Twelve strains of H. pylori were tested. They were isolated from biosamples from 23 patients with stomach inflammation (16 persons) and stomach (3) and duodenum peptic ulcer. By application of solid medium dilution of MIC50 and MIC90-16 antibiotics and antimicrobials were tested. Values of MIC50 and MIC90 for antibiotics from the tetracycline group were, respectively 0.25-0.5 microgram/ml and 0.12-1.0 microgram/ml. Similar results were obtained with macrolide antibiotics. All strains were sensitive to penicillin (MIC 0.03-0.12 microgram/ml, ampicillin (MIC 0.06-0.5 microgram/ml) and amoxicillin and rifampicin (MIC 0.07-0.3 microgram/ml). Ten out of 12 investigated strains were resistant to metronidazole (MIC90 = 30 micrograms/ml). Results of this study may be important for etiotropic treatment of infections with H. pylori.     

Influence of the amount of ferromagnetic addition on the rheological properties of spinning solutions,the structure,the strength,and thermal properties of polyacrylonitrile fibres

The rheological properties of spinning solutions of polyacrylonitrile in dimethyl formamide (DMF) containing various amounts of a ferromagnetic nanoaddition were investigated. The porous structure, the strength and thermal properties of fibers obtained from these solutions were assessed, as well as the uniformity of the nanoaddition distribution on the fiber surface was estimated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Regular Languages of Thin Trees

An infinite tree is called thin if it contains only countably many infinite branches. Thin trees can be seen as intermediate structures between infinite words and infinite trees. In this work we investigate properties of regular languages of thin trees. Our main tool is an algebra suitable for thin trees. Using this framework we characterize various classes of regular languages: commutative, open in the standard topology, and definable in weak MSO logic among all trees. We also show that in various meanings thin trees are not as rich as all infinite trees. In particular we observe a collapse of the parity index to the level (1, 3) and a collapse of the topological complexity to co-analytic sets. Moreover, a gap property is shown: a regular language of thin trees is either weak MSO-definable among all trees or co-analytic-complete.     

Molecular mechanism of temporal physico/chemical changes that take place during imidization of polyamic acid: Coupled real-time rheo-optical and IR dichroism measurements

Multiple overlapping physical and chemical changes often take place during casting/drying and imidization from PMDA-ODA polyamic acid precursors from cast solutions. To shed light into details of these complex phenomena, we designed a unique real time measurement system that combines true stress, true strain, in-plane birefringence and temperature with polarized ultra-rapid scan FT-IR spectrometry (URS-FT-IR). At the early stages of heating (21°C–130 °C), initially isotropic solution cast film was observed to develop stress and birefringence as the solvent decomplexed and evaporated without showing any imidization as it was held in uniaxially constrained state. At a temperature around 130 °C, the onset of imidization reaction was detected while the stress went through a maximum. Beyond this stage, the evaporation of bound solvent and chemical conversion was observed to take place simultaneously and this is accompanied by a steady increase in birefringence. As the majority of the bound solvent evaporated, the stress and birefringence values started leveling off at long times.     

Sharpening filter for false color imaging of dual-energy X-ray scans

Dual-energy X-ray imaging has a vast range of application in security. Luggage inspection is an essential process for an airplane or court house security as well as securing mass events. An image of a content of some package may help to figure out if there is any dangerous object inside and avoid possibly threatening situation. As the raw X-ray images are not always easy to analyze and interpret, some image processing methods like an object detection, a frequency resolution increase or a pseudocoloring are being used. Since color can be a powerful tool to improve the usefulness of an information display, we propose pseudocoloring improvement by modifying material-based approach with edge detection to fill and sharpen color layers over the image making it easier to read and analyze. We demonstrate the effectiveness of the methods using real data, acquired from a professional dual-energy X-ray scanner.     

Nominal Monoids

We develop an algebraic theory for languages of data words. We prove that, under certain conditions, a language of data words is definable in first-order logic if and only if its syntactic monoid is aperiodic.     

Finite satisfiability for guarded fixpoint logic

The finite satisfiability problem for guarded fixpoint logic is decidable and complete for 2ExpTime (resp. ExpTime for formulas of bounded width).     

Processing characteristics and structure development in solid-state extrusion of bacterial copolyesters: Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

The bacterial copolyesters poly(3-hydroxybutyrate-co-3-hydroxyvalerate) have been successfully commercialized by ICI and are currently being distributed worldwide. Because of their bacterial origin, they are completely biodegradable. This has opened up numerous opportunities to develop new environmentally friendly products. The solid-state extrusion of a series of biodegradable copolyesters (P(3HB-3HV)) was performed in our laboratory with the aim of gaining fundamental understanding about their processability below their melting temperatures. The extrudability windows were found to span the temperature range from 135 to 150°C, depending on the composition of the samples under our experimental setup. The solid-state extrudates were found to exhibit an extra melting endotherm about 15–20°C above their normal melting temperature. This high temperature melting peak increasingly became dominant at lower extrusion temperatures. Wide angle X-ray diffraction studies did not indicate any phase change that might be responsible for this increase in the melting point. Contrary to the expectations, the solid-state extruded samples did not show significant chain orientation along the extrusion direction. This might be a result of fracture of the mass in the barrel into smaller pieces and their randomization during the course of their passage through the die. When the extrusion temperature was raised closer to the melting temperature, the quality of the extrudates was improved, and this was reflected in improvement of their mechanical properties. © 1996 John Wiley & Sons, Inc.