Search results for "film."
showing 10 items of 4451 documents
The modelling of the cathode sheath of an electrical arc in vacuum
2003
This paper presents a simple model of the fragment in the cathode electrical arc root taking into account the physical phenomena occuring on the cathode surface and the sheath. The goal is the obtainment of characteristics values of the heat flux, the electrons, and atoms density in the sheath. Computation is carried out on a one-dimensional model with a coupling between the equation obtained in the sheath and an enthalpy model of the cathode to describe the temperature evolution. In the modelling, we introduce a friction zone above the sheath edge to characterize the heavy particle interactions. Numerical simulation shows that the ionic friction phenomenon deriving from ion–atom collision …
Innovative ready to use carrier-bacteria devices for bioremediation of oil contaminated water
2018
Bioremediation, that uses microorganisms to remove environmental pollutants, is the best way of restoring the environment due to its low cost and sustainability. Immobilization of microorganisms capable of degrading specific contaminants significantly promotes bioremediation processes. An innovative ready to use bioremediation system to clean up oil-contaminated water was developed immobilizing highly performant marine and soil HC degrading bacteria, on biodegradable oil-absorbing carriers. Two soil Actinobacteria (Gordonia sp. SoCg, Nocardia sp. SoB) and two marine Gammaproteobacteria (Alcanivorax sp. SK2, Oleibacter sp.5), were immobilized on biopolymeric membranes prepared by electrospin…
Efficacy of an amine fluoride-triclosan mouthrinse as compared to the individual active ingredients
2003
Background: The purpose of the clinical study was to examine the antibacterial and plaque-reducing properties of mouthrinses containing triclosan (TRI), amine fluoride (AmF), and the combination of both (AFT) on 4-day plaque regrowth. A placebo solution (PLA) and a 0.2% chlorhexidine solution (CHX) served as negative and positive controls, respectively. Materials & Methods: After a professional tooth cleaning (day 0), 15 volunteers refrained from all mechanical oral hygiene measures for the next 96 h and rinsed instead twice daily for 1 min with 10 ml of one of the five randomly assigned solutions. Plaque index (PlI), which was assessed after 24 and 96 h (PlI1, PlI2), and plaque area of the…
Specific separation and recovery of phosphate anions by a novel NiFe-LDH/rGO hybrid film based on electroactivity-variable valence
2022
Phosphorus is a non-renewable resource. Supplies are limited and much phosphorus is currently wasted during the production and utilization process, causing concerns about future supplies and widespread environmental problems. To solve these problems, a new type of NiFe-LDH/rGO electrically switched ion-selective (ESIX) film is designed, based on the dominant mechanism of inner-sphere complexation. An ESIX process allows the NiFe-LDH/rGO hybrid film to achieve a controllably selective uptake and release of the phosphate anions. This route involves tuning potential steps to regulate the redox states of the composite film and the variable metal (e.g., Ni, Fe (II)/(III)) in coordination centers…
Mono- and Multi-Layers
2006
Thin films incorporating or consisting of calixarenes have been widely investigated. The capacity of such films to adsorb both ions and neutral species has engendered particular interest in their use in sensor devices. Semiconductors, non-linear optical and pyroelectric materials or switchable systems for data storage are further examples of their potential use [1]. Both monoand multi-layer films can be formed from calixarenes and resorcarenes, using a variety of techniques. This chapter deals with the fundamental basis of calixarene thin film applications, including film formation and characterisation as well as studies of selectivity in small molecule interactions. Real and potential appl…
Endocarditis due to Abiotrophia defectiva, a biofilm-related infection associated with the presence of fixed braces
2017
Abstract Rationale: Endocarditis with Abiotrophia defectiva represents 4.3% to 6% of all streptococcal endocarditis. The article presents diagnosis issues and the complexity of the treatment. Patient concerns: We present the case of a female white patient, aged 26 years, who developed infectious endocarditis caused by A defectiva, in the last trimester of pregnancy, a biofilm-related infection associated with the presence of fixed braces. Diagnoses: The diagnosis of infectious endocarditis was confirmed by the cardiac ultrasound examination that revealed a voluminous vegetation on the mitral valve, and acute mitral regurgitation caused by chordae tendinae rupture, and also by isolating Abio…
Metagenomic investigation of bacteria associated with dental lesions : a cross-sectional study
2019
Background Dental caries is considered as one of the most significant global health problem over the world. Dental caries initiates from bacterial shifts within the supragingival biofilm, then a polymicrobial biofilm is formed on the surface of tooth, and finally various bacterial species aggregate in a complex-organized manner. The exploiting variability in 16S rRNA gene sequence has been considered as a cost-efficient high-throughput characterization approach in human oral microbiome investigations. The aim of this study is to characterize bacterial species associated with superficial dental biofilm, underlying carious dentine and root caries lesion by16S rRNA gene-based metagenomic analy…
Bacteria associated with periodontal disease are also increased in health.
2020
Background The objective of this cross-sectional clinical study was to analyze the differences in the microbiome in gingival sulci of adult patients in the presence or absence of chronic periodontitis. Material and Methods Patients with or without periodontal disease were included in this cross-sectional study. Subgingival biofilm samples were collected and analyzed by 16S massive pyrosequencing. Functional analyses were also performed. Results A total of 15 phyla, 154 genera and 351 species were detected globally. Differences between disease and non-disease samples were observed in all taxonomical levels which suggest functional profile changes in the community. It was found that the main …
Phenotypic and genetic analysis of biofilm formation by Staphylococcus epidermidis.
2012
Objective. The most important virulence factor of Staphylococcus epidermidis is their capability to form a biofilm on the surfaces of implanted medical devices. The accumulative phase of biofilm formation is linked to the production of intercellular adhesin encoded by the icaADBC operon and accumulation-associated protein by the aap gene. The aim of the study was to investigate biofilm formation phenotypically and genetically in clinical strains of S. epidermidis in comparison with commensal strains. Material and Methods. The study was carried out in 4 hospitals in Riga, Latvia. In total, 105 clinical strains of Staphylococcus epidermidis isolated from patients’ blood (n=67) and intravenous…
Doxepin and its metabolites in plasma and cerebrospinal fluid in depressed patients
1997
Little information exists on the concentrations of antidepressants and their metabolites in CSF. We measured plasma and CSF levels of trans-doxepin (trans-DOX) and DOX metabolites in 12 depressed patients treated with DOX (250 mg/day) for 6 days. Spinal taps and blood samples were taken on day 7, 10 h after drug administration. Trans-DOX, cis-desmethyldoxepin (cis-DM-DOX), trans-desmethyldoxepin (trans-DM-DOX) and di-desmethyldoxepin (DDM-DOX) were analyzed in CSF and plasma samples by HPLC with column-switching. Although DOX was given as a mixture of 85% trans-DOX and 15% of the pharmacologically more active cis-DOX, we found similar amounts of cis-DM-DOX and trans-DM-DOX in plasma (59.8 +…