Investigative Techniques Commons^™

Development Of A Method For Quantification Of Toluene Diisocyanate And Methylenediphenyl Diisocyanate Migration From Polyurethane Foam Sample Surface To Artificial Sweat By Hplc-Uv-Ms, Aleksandra Donchenko, Simon Aubin, Sébastien Gagné, Mark Spence, Livain Breau, Jacques Lesage

Études primaires

The US Environmental protection agency (EPA) has published guidance that includes test procedures for evaluating indoor exposure to chemicals from products. One of the test procedures represents the migration test for evaluating potential dermal exposure from home furniture. Such an evaluation involves the chemical measurement of the sweat which is currently unavailable in the literature. The objective of this project was to develop and validate an analytical method for quantification of migration of 4,4′-methylenediphenyl diisocyanate (MDI), 2,6-toluene diisocyanate (2,6-TDI) and 2,4-toluene diisocyanate (2,4-TDI) from a polyurethane (PU) flexible foam to artificial sweat that meets the recommendations of the EPA test …

On Site Comparison Of The Osha 42, Asset Ez4-Nco, Iso-Chek, Dan And Cip10 Methods For Measuring Toluene Diisocyanate (Tdi) At A Polyurethane Foam Factory, Simon Aubin, El Mekki Hamdi, Audrey Joly, Philippe Sarazin, Jacques Lesage, Livain Breau, Mark Spence, Sébastien Gagné

Études primaires

Because of the semi-volatile nature of diisocyanates (being airborne in both physical vapor and particulate phases), their high reactivity and low occupational exposure limits, diisocyanate exposure evaluation has been challenging for industrial hygienists and laboratories. The objective of this study was to compare the toluene diisocyanate (2,4 and 2,6 isomers, TDI) concentration measured by five methods in a flexible polyurethane foam factory using different collection or derivatization approaches. The methods used were: OSHA 42 modified (filter, 1-(2-pyridyl)piperazine) (OSHA), Asset EZ4-NCO (denuder and filter, dibutylamine) (Asset), Iso-Chek (double-filter, 9-(N-methylaminomethyl) anthracene and 1,2-methoxyphenylpiperazine), DAN (filter, 1,8-diaminonaphthalene), and CIP10 (centrifugation, 1,2-methoxyphenylpiperazine). Particle real-time …

On-Site Comparison Of The Osha 47, Asset Ez4-Nco, Iso-Chek, Dan, And Cip10 Methods For Measuring Methylene Diphenyl Diisocyanate (Mdi) At An Oriented-Strand Board (Osb) Factory, Simon Aubin, El Mekki Hamdi, Audrey Joly, Philippe Sarazin, Jacques Lesage, Livain Breau, Mark Spence, Sébastien Gagné

Études primaires

Diisocyanates are occupational contaminants and known sensitizers causing irritation (skin and respiratory tract) as well as occupational asthma. Because of their physicochemical properties (semi-volatile and high reactivity) and low occupational limits, diisocyanate exposure evaluation is still a challenge nowadays for industrial hygienists and laboratories. The objective of this study was to compare the methylene diphenyl diisocyanate (MDI) concentrations measured by five methods using different collection or derivatization approaches in an oriented-strand board (OSB) factory. The methods used were: OSHA 47 (filter, 1-(2-pyridyl)piperazine) (OSHA), Asset EZ4-NCO (denuder and filter, dibutylamine) (Asset), Iso-Chek (double-filter, 9-(N-methylaminomethyl) anthracene and 1,2-methoxyphenylpiperazine), DAN (filter, 1,8-diaminonaphthalene), and …

Validation Of A Low-Cost Inertial Motion Capture System For Whole-Body Motion Analysis, X. Robert-Lachaine, H. Mecheri, A. Muller, C. Larue, A. Plamondon

Études primaires

While some low-cost inertial motion capture (IMC) systems are now commercially available, generally, they have not been evaluated against gold standard optical motion capture (OMC). The objective was to validate the low-cost Neuron IMC system with OMC. Whole-body kinematics were recorded on five healthy subjects during manual handling of boxes for about 32 min while wearing 17 magnetic and inertial measurement units with Optotrak clusters serving as a reference. The kinematical model was calibrated anatomically for OMC and with poses for IMC. Local coordinate systems were aligned with angular velocities to dissociate differences due to technology or kinematical model. Descriptive …

Conception D’Oreilles Artificielles Réalistes Dédiées À L’Étude Du Confort Acoustique Et Physique Des Protecteurs Auditifs Intra-Auriculaires, Simon Benacchio, Olivier Doutres, Éric Wagnac, Franck Sgard

Rapports de recherche scientifique

Au Québec, environ 360 000 travailleurs sont exposés quotidiennement à des niveaux de bruit susceptibles d’engendrer des problèmes d’audition. Les protecteurs auditifs individuels sont souvent utilisés pour pallier ce problème. Cependant, l’inconfort lié à l'utilisation de ces protecteurs limite la durée du port et donc l'efficacité de la protection. Le développement d'outils de conception acoustique minimisant les sources d’inconforts auditifs et physiques de ces protecteurs tout en assurant une atténuation adéquate constitue le contexte de cette recherche.

La présente étude se concentre sur deux indicateurs du confort associés au port des bouchons d’oreille : l’atténuation et l’effet d’occlusion. L’atténuation quantifie …

Mechanisms Of Value-Biased Prioritization In Fast Sensorimotor Decision Making, Kivilcim Afacan-Seref

Dissertations and Theses

In dynamic environments, split-second sensorimotor decisions must be prioritized according to potential payoffs to maximize overall rewards. The impact of relative value on deliberative perceptual judgments has been examined extensively, but relatively little is known about value-biasing mechanisms in the common situation where physical evidence is strong but the time to act is severely limited. This research examines the behavioral and electrophysiological indices of how value biases split-second perceptual decisions and the possible mechanisms underlying the process. In prominent decision models, a noisy but statistically stationary representation of sensory evidence is integrated over time to an action-triggering bound, and value-biases …

Comparative Performance Of The Nanoscan And The Classic Smps In Determining N95 Filtering Facepiece Efficiency Against Nanoparticles, Clothilde Brochot, Fariborz Haghighat, Ali Bahloul

Études primaires

Nanoparticles are defined as particles with at least one dimension in the range of 1–100 nm. Due to the special properties of nanoparticles, they are used in many workplaces, thus leading to occupational exposure. Filtering facepieces (FFPs) are generally used in these workplaces to reduce the exposure. Many studies have measured FFP efficiency in laboratories using a scanning mobility particle sizer (SMPS). The aim of this study was to determine whether a NanoScan could be used to measure FFP efficiency against nanoparticles in workplaces for one type of N95 FFP. The results showed that the NanoScan gave maximum penetration and …

Single-Molecule Analysis Of Subtelomeres And Telomeres In Alternative Lengthening Of Telomeres (Alt) Cells, Heba Z. Abid, Jennifer Mccaffrey, Kaitlin Raseley, Eleanor Young, Katy Lassahn, Dharma Varapula, Harold Riethman, Ming Xiao

School of Medical Diagnostics & Translational Sciences Publications

BACKGROUND: Telomeric DNA is typically comprised of G-rich tandem repeat motifs and maintained by telomerase (Greider CW, Blackburn EH; Cell 51:887-898; 1987). In eukaryotes lacking telomerase, a variety of DNA repair and DNA recombination based pathways for telomere maintenance have evolved in organisms normally dependent upon telomerase for telomere elongation (Webb CJ, Wu Y, Zakian VA; Cold Spring Harb Perspect Biol 5:a012666; 2013); collectively called Alternative Lengthening of Telomeres (ALT) pathways. By measuring (TTAGGG) n tract lengths from the same large DNA molecules that were optically mapped, we simultaneously analyzed telomere length dynamics and subtelomere-linked structural changes at a large …

Tunable Multiphase Dynamics Of Arginine And Lysine Liquid Condensates, Rachel S. Fisher, Shana Elbaum-Garfinkle

Advanced Science Research Center

Liquid phase separation into two or more coexisting phases has emerged as a new paradigm for understanding subcellular organization, prebiotic life, and the origins of disease. The design principles underlying biomolecular phase separation have the potential to drive the development of novel liquid-based organelles and therapeutics, however, an understanding of how individual molecules contribute to emergent material properties, and approaches to directly manipulate phase dynamics are lacking. Here, using microrheology, we demonstrate that droplets of poly-arginine coassembled with mono/polynucleotides have approximately 100 fold greater viscosity than comparable lysine droplets, both of which can be finer tuned by polymer length. We …

Molecular And Behavioral Mechanisms Mediated Paclitaxel-Induced Changes In Affect-Like Behavior In Mice, Julia Meade

Theses and Dissertations

Paclitaxel and oxaliplatin are two chemotherapeutics that cause acute neurotoxicity and chemotherapy-induce peripheral neuropathy (CIPN) in 70-90% of cancer patients. Chemotherapy-induced sensory changes are correlated with depression and anxiety. We characterized the effects of these drugs on sensation and various mood-related behaviors in mice, to determine if changes in sensation are associated with depression-like behavior, to explore putative mechanisms of chemotherapy-induced depression-like behavior (Aim 1), and to develop a mouse model of chemotherapy-induced operant responding deficit (Aim 2). In Aim 1, we observed that a cumulative dose of 32 mg/kg paclitaxel induced mechanical hypersensitivity and transiently reduced preference for sucrose …

Vibrational Spectroscopy For In Vitro Monitoring Stem Cell Differentiation, Francesca Ravera, Esen Efeoglu, Hugh Byrne

Other resources

Stem cell technology has attracted considerable attention over recent decades due to its enormous potential in regenerative medicine and disease therapeutics. Studying the underlying mechanisms of stem cell differentiation and tissue generation is critical, and robust methodologies and different technologies are required. Towards establishing improved understanding and optimised triggering and control of differentiation processes, analytical techniques such as flow cytometry, immunohistochemistry, reverse transcription polymerase chain reaction, RNA in situ hybridisation analysis, and fluorescence-activated cell sorting have contributed much. However, progress in the field remains limited because such techniques provide only limited information, as they are only able to address specific, …

Visual Estimates Of Blood Loss By Medical Laypeople: Effects Of Blood Loss Volume, Victim Gender, And Perspective, Rachel Phillips, Marc Friberg, Mattias Lantz Cronqvist, Carl-Oscar Jonson, Erik Prytz

Psychology Faculty Publications

A severe hemorrhage can result in death within minutes, before professional first responders have time to arrive. Thus, intervention by bystanders, who may lack medical training, may be necessary to save a victim's life in situations with bleeding injuries. Proper intervention requires that bystanders accurately assess the severity of the injury and respond appropriately. As many bystanders lack tools and training, they are limited in terms of the information they can use in their evaluative process. In hemorrhage situations, visible blood loss may serve as a dominant cue to action. Therefore, understanding how medically untrained bystanders (i.e., laypeople) perceive hemorrhage …