252 research outputs found
Quantification of the Fraction of Particulate Matter Derived from a Range of C-13-Labeled Fuels Blended into Heptane, Studied in a Diesel Engine and Tube Reactor
This paper presents the results of an experimental study that was carried out to determine the conversion rates to particulate matter (PM) of several liquid fuel hydrocarbon molecules and specific carbon atoms within those molecules. The fuels investigated (ethanol, n-propanol, i-propanol, acetone, and toluene) were blended in binary mixtures with n-heptane to a level of 10 mol percent. The contribution of the additive molecules to PM was quantified using a carbon-13 (13C) labeling experiment, in which the fuel of interest was enriched with 13C to serve as an atomic tracer. Measurement of the 13C/12C in the fuel and in the resulting PM was carried out using isotope ratio mass spectrometry. The fuel binary mixtures were tested under pyrolysis conditions in a tube reactor and also combusted in a direct injection compression ignition engine. In the tube reactor, samples were generated under oxygen-free pyrolysis conditions and at a temperature of 1300 °C, while the engine experiments were carried out at an intermediate load. Both in the tube reactor and in the engine it was found that, dependent on the fuel molecular structure, there were significant differences in the overall conversion rates to PM of the fuel molecules and of the “submolecular” carbon atoms. A separate experiment was also carried out in the compression ignition engine, with n-heptane as fuel, in order to determine the contribution of the engine lubrication oil to exhaust PM; the results showed that a significant portion (∼60%) of the total particulate was derived from the lubrication oil
Les grands marquages de thons de la CTOI 2005-2009 : les principaux résultats préliminaires des marquages et quelques unes de leurs conséquences
PARP-1 dependent recruitment of the amyotrophic lateral sclerosis-associated protein FUS/TLS to sites of oxidative DNA damage
Amyotrophic lateral sclerosis (ALS) is associated with progressive degeneration of motor neurons. Several of the genes associated with this disease encode proteins involved in RNA processing, including fused-in-sarcoma/translocated-in-sarcoma (FUS/TLS). FUS is a member of the heterogeneous nuclear ribonucleoprotein (hnRNP) family of proteins that bind thousands of pre-mRNAs and can regulate their splicing. Here, we have examined the possibility that FUS is also a component of the cellular response to DNA damage. We show that both GFP-tagged and endogenous FUS re-localize to sites of oxidative DNA damage induced by UVA laser, and that FUS recruitment is greatly reduced or ablated by an inhibitor of poly (ADP-ribose) polymerase activity. Consistent with this, we show that recombinant FUS binds directly to poly (ADP-ribose) in vitro, and that both GFP-tagged and endogenous FUS fail to accumulate at sites of UVA laser induced damage in cells lacking poly (ADP-ribose) polymerase-1. Finally, we show that GFP-FUS(R521G), harbouring a mutation that is associated with ALS, exhibits reduced ability to accumulate at sites of UVA laser-induced DNA damage. Together, these data suggest that FUS is a component of the cellular response to DNA damage, and that defects in this response may contribute to ALS
Further investigations of underground resistivity structures in coastal areas using grounded-source airborne electromagnetics
Inventory of long and short term future needs of food chain users for future functions of internet
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A systematic review of contamination (aerosol, splatter and droplet generation) associated with oral surgery and its relevance to COVID-19
IntroductionThe current COVID-19 pandemic caused by the SARS-CoV-2 virus has impacted the delivery of dental care globally and has led to re-evaluation of infection control standards. However, lack of clarity around what is known and unknown regarding droplet and aerosol generation in dentistry (including oral surgery and extractions), and their relative risk to patients and the dental team, necessitates a review of evidence relating to specific dental procedures. This review is part of a wider body of research exploring the evidence on bioaerosols in dentistry and involves detailed consideration of the risk of contamination in relation to oral surgery.MethodsA comprehensive search of Medline (OVID), Embase (OVID), Cochrane Central Register of Controlled Trials, Scopus, Web of Science, LILACS and ClinicalTrials.Gov was conducted using key terms and MeSH (Medical Subject Headings) words relating to the review questions. Methodological quality including sensitivity was assessed using a schema developed to measure quality aspects of studies using a traffic light system to allow inter- and intra-study overview and comparison. A narrative synthesis was conducted for assessment of the included studies and for the synthesis of results.ResultsEleven studies on oral surgery (including extractions) were included in the review. They explored microbiological (bacterial and fungal) and blood (visible and/or imperceptible) contamination at the person level (patients, operators and assistants) and/or at a wider environmental level, using settle plates, chemiluminescence reagents or air samplers; all within 1 m of the surgical site. Studies were of generally low to medium quality and highlighted an overall risk of contaminated aerosol, droplet and splatter generation during oral surgery procedures, most notably during removal of impacted teeth using rotatory handpieces. Risk of contamination and spread was increased by factors, including proximity to the operatory site, longer duration of treatment, higher procedural complexity, non-use of an extraoral evacuator and areas involving more frequent contact during treatment.ConclusionA risk of contamination (microbiological, visible and imperceptible blood) to patients, dental team members and the clinical environment is present during oral surgery procedures, including routine extractions. However, the extent of contamination has not been explored fully in relation to time and distance. Variability across studies with regards to the analysis methods used and outcome measures makes it difficult to draw robust conclusions. Further studies with improved methodologies, including higher test sensitivity and consideration of viruses, are required to validate these findings
Rhetoric But Whose Reality? The Influence of Employability Messages on Employee Mobility Tactics and Work Group Identification
Over the last decade, employability has been presented by its advocates as the solution to employment uncertainty, and by its critics as a management rhetoric possessing little relevance to the experiences of most workers. This article suggests that while employability has failed to develop into a key research area, a deeper probing of its message is warranted. In particular, it is suggested that employability may have resonance with employees as workers rather than as employees of their immediate employing organisation. This demands a slightly different approach to studying employability than some other related phenomena such as employee commitment which has resonance only in relation to the employing organization. In adopting a social identity approach, the significance of the employability message is shown not only to lie in employees’ willingness to disassociate from their existing work groups and pursue individual mobility, but also in its capacity to undermine workers’ collective responses to grievances and unwanted organizational changes. A future research agenda is presented which highlights the need to address recent attempts to develop employability expectations among graduate career entrants, and for a closer critical engagement with management writings that attempt to justify the unnecessary espousal of the self development message
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