34 research outputs found

    Does exposure to inflammatory particles modify the pattern of anion in exhaled breath condensate?

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    Exposure to environmental and occupational particulate matter (PM) induces health effects on the cardio-pulmonary system. In addition, associations between exposure to PM and metabolic syndromes like diabetes mellitus or obesity are now emerging in the literature. Collection of exhaled breath condensate (EBC) is an appealing non-invasive technique to sample pulmonary fluids. This hypothesis-generating study aims to (1) validate an ion chromatography method allowing the robust determination of different metabolism-related molecules (lactate, formate, acetate, propionate, butyrate, pyruvate, nitrite, nitrate) in EBC; (2) apply this method to EBC samples collected from workers exposed to quartz (a known inflammatory particle), to soapstone (a less inflammatory particle than quartz), as well as to controls. A multi-compound standard solution was used to determine the linearity range, detection limit, repeatability and bias from spiked EBC. The biological samples were injected without further treatment into an ion chromatograph with a conductivity detector. RTube <sup>Âź</sup> were used for field collection of EBC from 11 controls, 55 workers exposed to soapstone and 12 volunteers exposed to quartz dust. The analytical method used proved to be adequate for quantifying eight anions in EBC samples. Its sub-micromolar detection limits and repeatability, combined with a very simple sample preparation, allowed an easy and fast quantification of different glycolysis or nitrosative stress metabolites. Using multivariate discriminant analysis to maximize differences between groups, we observed a different pattern of anions with a higher formate/acetate ratio in the EBC samples for quartz exposed workers compared to the two other groups. We hypothesize that a modification of the metabolic signature could be induced by exposure to inflammatory particles like quartz and might be observed in the EBC via a change in the formate/acetate ratio

    Method validation of nanoparticle tracking analysis to measure pulmonary nanoparticle content: the size distribution in exhaled breath condensate depends on occupational exposure

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    A particle exposure assessment based on the dose deposited in the lungs would be the gold standard for the evaluation of any resulting health effects. Measuring particles in exhaled breath condensate (EBC)-a matrix containing water and airway lining fluid-could help to evaluate particle retention in the lungs. This study aimed to (1) validate a nanoparticle tracking analysis (NTA) method for determining the particle number concentration and their hydrodynamic size distribution in EBC, and (2) apply this method to EBC collected from workers exposed to soapstone (n = 55) or quartz dust (n = 12) and controls (n = 11). A standard latex bead solution was used to determine the linear range, limit of detection (LOD), repeatability (coefficient of variation, CV), and bias in spiked EBC. An LM10 NanoSight instrument with NTA version 3.1 software was used for measurement. RTubes(Âź) were used for field collection of EBC. The repeatability obtained for a D50 size distribution in EBC showed less than 8% variability, with a bias <7%. The particle concentration was linear in the range ≀2.5 × 10(8) particles ml(-1) with a LOD of 4 × 10(6) particles ml(-1). A recovery of 117 ± 20% at 6.2 × 10(7) particles ml(-1) was obtained with a CV <10% and a bias <20%. EBC from workers exposed to quartz, who experienced the largest exposure to silica particles, consistently exhibited a statistically significant (p < 0.01) higher concentration of particles in their EBC, with a size distribution shift towards larger values than the other groups. Results showed that the NTA technique performed well for characterizing the size distribution and concentrations of particles in EBC. The technique needs to be corroborated with a larger population of workers

    A rapid-response ultrasensitive biosensor for influenza virus detection using antibody modified boron-doped diamond

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    According to the World Health Organization (WHO), almost 2 billion people each year are infected worldwide with flu-like pathogens including influenza. This is a contagious disease caused by viruses belonging to the family Orthomyxoviridae. Employee absenteeism caused by flu infection costs hundreds of millions of dollars every year. To successfully treat influenza virus infections, detection of the virus during the initial development phase of the infection is critical, when tens to hundreds of virus-associated molecules are present in the patient’s pharynx. In this study, we describe a novel universal diamond biosensor, which enables the specific detection of the virus at ultralow concentrations, even before any clinical symptoms arise. A diamond electrode is surface-functionalized with polyclonal anti-M1 antibodies, which then serve to identify the universal biomarker for the influenza virus, M1 protein. The absorption of the M1 protein onto anti-M1 sites of the electrode change its electrochemical impedance spectra. We achieved a limit of detection of 1 fg/ml in saliva buffer for the M1 biomarker, which corresponds to 5–10 viruses per sample in 5 minutes. Furthermore, the universality of the assay was confirmed by analyzing different strains of influenza A virus

    Évaluation des risques biologiques pour les personnels de soins : de l’évaluation a priori Ă  l’expĂ©rimentation

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    But de l’étudeL’exposition des personnels de soins aux risques biologiques est inhĂ©rente Ă  l’activitĂ© professionnelle dans ce milieu, mais les mĂ©thodes d’évaluation de ces risques sont encore limitĂ©es. L’objectif de ce travail est double : d’une part, Ă©laborer un guide d’évaluation Ă  partir des donnĂ©es de la littĂ©rature biomĂ©dicale et des donnĂ©es locales d’hospitalisation ou d’analyses microbiologiques, pour les germes les plus couramment rencontrĂ©s en milieu de soins, d’autre part, valider l’utilisation d’un impacteur mono-Ă©tage dans l’évaluation des expositions. MatĂ©riel et mĂ©thode Ce travail s’est dĂ©roulĂ© selon deux grands axes : synthĂšse des informations existantes, identification et synthĂšse des documents scientifiques existants portant sur l’exposition des personnels de soins aux agents biologiques et sur les circonstances des expositions, puis rĂ©alisation et validation d’un guide des expositions a priori aux risques biologiques en milieu de soins. Utilisation d’un impacteur mono-Ă©tage pour Ă©valuer la prĂ©sence de staphylocoques rĂ©sistant Ă  la mĂ©thicilline dans les chambres de patients infectĂ©s ou colonisĂ©s par ce germe. Les prĂ©lĂšvements ont Ă©tĂ© rĂ©alisĂ©s sur des milieux gĂ©losĂ©s sĂ©lectifs, et les souches retrouvĂ©es ont Ă©tĂ© comparĂ©es aux souches portĂ©es par les patients. RĂ©sultats Les documents de synthĂšse sur les expositions des soignants aux risques biologiques, sur les contextes des expositions et sur les recommandations en termes de vaccinations basĂ©es sur les prescriptions rĂ©glementaires et les connaissances scientifiques ont Ă©tĂ© Ă©laborĂ©s et sont disponibles sur le site Internet http://wwww.chu-rouen.fr/mtph. Il concerne une vingtaine de germes reconnus comme les principaux risques biologiques en milieu de soins. Les rĂ©sultats obtenus avec l’impacteur mono-Ă©tage confirment qu’il peut ĂȘtre valablement utilisĂ© pour mesurer l’exposition aĂ©rienne aux germes cultivables

    A rapid-response ultrasensitive biosensor for influenza virus detection using antibody modified boron-doped diamond

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    According to the World Health Organization (WHO), almost 2 billion people each year are infected worldwide with flu-like pathogens including influenza. This is a contagious disease caused by viruses belonging to the family Orthomyxoviridae. Employee absenteeism caused by flu infection costs hundreds of millions of dollars every year. To successfully treat influenza virus infections, detection of the virus during the initial development phase of the infection is critical, when tens to hundreds of virus-associated molecules are present in the patient’s pharynx. In this study, we describe a novel universal diamond biosensor, which enables the specific detection of the virus at ultralow concentrations, even before any clinical symptoms arise. A diamond electrode is surface-functionalized with polyclonal anti-M1 antibodies, which then serve to identify the universal biomarker for the influenza virus, M1 protein. The absorption of the M1 protein onto anti-M1 sites of the electrode change its electrochemical impedance spectra. We achieved a limit of detection of 1 fg/ml in saliva buffer for the M1 biomarker, which corresponds to 5–10 viruses per sample in 5 minutes. Furthermore, the universality of the assay was confirmed by analyzing different strains of influenza A virus

    Analysis of nitrogen oxides (NOx) in the exhaled breath condensate (EBC) of subjects with asthma as a complement to exhaled nitric oxide (FeNO) measurements: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>The study of pulmonary biomarkers with noninvasive methods, such as the analysis of exhaled breath condensate (EBC), provides a useful approach to the pathophysiology of asthma. Although many recent publications have applied such methods, numerous methodological pitfalls remain. The first stage of our study consisted of validating methods for the collection, storage and analysis of EBC; we next sought to clarify the utility of analysing nitrogen oxides (NOx) in the EBC of asthmatics, as a complement to measuring exhaled nitric oxide (FeNO).</p> <p>Methods</p> <p>This hospital-based cross-sectional study included 23 controls matched with 23 asthmatics. EBC and FeNO were performed and respiratory function measured. Intra-assay and intra-subject reproducibility were assessed for the analysis of NOx in the EBC of 10 healthy subjects.</p> <p>Results</p> <p>The intraclass correlation coefficient (ICC) was excellent for intra-assay reproducibility and was moderate for intra-subject reproducibility (Fermanian's classification). NOx was significantly higher in asthmatics (geometric mean [IQR] 14.4 ÎŒM [10.4 - 19.7] vs controls 9.9 ÎŒM [7.5 - 15.0]), as was FeNO (29.9 ppb [17.9 - 52.4] vs controls 9.6 ppb [8.4 - 14.2]). FeNO also increased significantly with asthma severity.</p> <p>Conclusions</p> <p>We validated the procedures for NOx analysis in EBC and confirmed the need for assays of other biomarkers to further our knowledge of the pathophysiologic processes of asthma and improve its treatment and control.</p

    Conception of using prediction tools in the robust schedules desining

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    The development of competitiveness on world markets caused the need to increase production flexibility. An essential tool in achieving this purpose could be production scheduling. Unfortunately, the production process is associated with presence of numerous random events that negatively affect its course. Therefore, it is necessary to apply appropriate prediction methods which help to reduce its affect. The paper presents the conception of robust production scheduling. The typical scheduling problems and robust scheduling idea are described. Moreover, the current solutions of production scheduling under uncertainty are outlined. Finally, the idea of creating robust schedules based on previous production processes are presented. In the final part of the paper the author presented problems related to proposed idea

    Growth and Isolation of Large Area Boron-Doped Nanocrystalline Diamond Sheets: A Route toward Diamond-on-Graphene Heterojunction

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    Many material device applications would benefit from thin diamond coatings, but current growth techniques, such as chemical vapor deposition (CVD) or atomic layer deposition require high substrate and gas‐phase temperatures that would destroy the device being coated. The development of freestanding, thin boron‐doped diamond nanosheets grown on tantalum foil substrates via microwave plasma‐assisted CVD is reported. These diamond sheets (measuring up to 4 × 5 mm in planar area, and 300–600 nm in thickness) are removed from the substrate using mechanical exfoliation and then transferred to other substrates, including Si/SiO_2 and graphene. The electronic properties of the resulting diamond nanosheets and their dependence on the free‐standing growth, the mechanical exfoliation and transfer processes, and ultimately on their composition are characterized. To validate this, a prototypical diamond nanosheet–graphene field effect transistor‐like (DNGfet) device is developed and its electronic transport properties are studied as a function of temperature. The resulting DNGfet device exhibits thermally activated transport (thermionic conductance) above 50 K. Below 50 K a transition to variable range hopping is observed. These findings demonstrate the first step towards a low‐temperature diamond‐based transistor
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