617 research outputs found

    A preliminary numerical investigation of airborne droplet dispersion in aircraft cabins

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    The emergence of the novel coronavirus has led to a global pandemic which has led to the airline industry facing severe losses. For air travel to recover, airlines need to ensure safe air travel. In this paper, the authors have modelled droplet dispersion after a single breath from an index patient. Computational Fluid Dynamics (CFD) simulations are conducted using the k-w SST turbulence model in ANSYS Fluent. The authors have taken into consideration several parameters such as the size of the mouth opening, the velocity of the cabin air as well as the number of droplets being exhaled by the index patient to ensure a realistic simulation. Preliminary results indicate that after a duration of 20s, droplets from the index patient disperse within a 10 m2 cabin area. About 75% of the droplets are found the disperse for up to 2m axially behind the index patient. This could possess an enhanced risk to passengers sitting behind the index patient. Ultimately, this paper provides an insight into the potential of CFD to visualise droplet dispersal and give impetus to ensuring necessary mitigating measures can be taken to reduce the risk of infection through droplet dispersal

    search for cpt and lorentz symmetry violation in neutral kaons at kloe kloe 2

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    The KLOE experiment at the DAΦNE φ -factory of the INFN Frascati Laboratory collected data corresponding to 2.5 fb−1 of integrated luminosity. Neutral kaon pairs produced in φ decays offers a unique possibility to perform tests of fundamental discrete symmetries. In this contribution the entanglement of the two kaons is exploited to search for possible violation of CPT symmetry and Lorentz invariance in the context of the Standard-Model Extension (SME) framework. A new approach to the analysis of φ → KSKL → π+π−,π+π− events has been adopted allowing us to independently measure all four CPT violating parameters ∆aμ appearing for neutral kaons in the SME. The final KLOE results on ∆aμ are presented: ∆a0 = (−6.0± 7.7stat ± 3.1syst)× 10−18 GeV ∆aX = ( 0.9± 1.5stat ± 0.6syst)× 10−18 GeV ∆aY = (−2.0± 1.5stat ± 0.5syst)× 10−18 GeV ∆aZ = ( 3.1± 1.7stat ± 0.5syst)× 10−18 GeV We also shortly discuss the perspectives for a new measurement using the KLOE-2 apparatus equipped with a new inner tracker

    Soil structure and bypass flwo processes in a Vertsol under sprinkler and drip irrigation.

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    In this paper morphological and physical characteristics, as well as flow behaviour of a Mediterranean Vertisol under the influence of two different irrigation systems currently used for irrigation, i.e. drip and sprinkler systems, were compared. No differences in soil texture, compaction and in potential cracking were found on cores from the two fields. However, field application of methylene blue showed the presence of continuous macropores, penetrating up to depths of 20-25 cm from the soil surface, in the field where the drip system was in use (field 1). This was considered to be the pre-existing soil structure. Instead, macropores terminating at a depth ranging between 5 and 10 cm from the soil surface were observed in the sprinkler irrigated field (field 2). The same difference in terms of macropores' continuity was also observed on soil cores sampled from the two irrigated fields. The higher raindrop impact and the non-point water application involved in the sprinkler irrigation system were assumed to have determined, during several years, the different depth of penetration of the macropores in the two fields. A different hydraulic behaviour was evidenced by laboratory measurement of bypass flow on soil cores taken from the two fields. Specifically, higher values of the saturated hydraulic conductivity were found in the cores from the drip irrigated field compared to those sampled in the sprinkler field. In addition no bypass flow was measured in the columns under the sprinkler field, while high rates and amounts of bypass flow were obtained in the cores taken from the drip irrigated field. The different hydraulic behaviour observed in the cores taken from the drip and from the sprinkler irrigated field was in agreement with the difference in terms of macropores' continuity between the two fields. Being bypass flow a mechanism inducing leaching of solutes, results of this investigation suggest that irrigation systems affecting soil structure, and altering macropores' continuity, should be avoided in clay soils. (c) 2006 Published by Elsevier B.

    One special question to start with: can HIF/NFkB be a target in inflammation?

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    Hypoxia and Inflammation are strictly interconnected with important consequences at clinical and therapeutic level. While cell and tissue damage due to acute hypoxia mostly leads to cell necrosis, in chronic hypoxia, cells that are located closer to vessels are able to survive adapting their phenotype through the expression of a number of genes, including proinflammatory receptors for alarmins. These receptors are activated by alarmins released by necrotic cells and generate signals for master transcription factors such as NFkB, AP1, etc. which control hundreds of genes for innate immunity and damage repair. Clinical consequences of chronic inflammatory reparative response activation include cell and tissue remodeling, damage in the primary site and, the systemic involvement of distant organs and tissues. Thus every time a tissue environment becomes stably hypoxic, inflammation can be activated followed by chronic damage and cell death or repair with vessel proliferation and fibrosis. This pathway can occur in cancer, myocardial infarction and stroke, diabetes, obesity, neurodegenerative diseases, chronic and autoimmune diseases and age-related diseases. Interestingly, proinflammatory gene expression can be observed earlier in hypoxic tissue cells and, in addition, in activated resident or recruited leukocytes. Herewith, the reciprocal relationships between hypoxia and inflammation will be shortly reviewed to underline the possible therapeutic targets to control hypoxia-related inflammation in a number of epidemiologically important human diseases and conditions

    A Cross-Sectional Survey on Burnout Prevalence and Profile in the Sicilian Population of Ambulance Driver-Rescuers

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    Introduction: Burnout is present at a high rate in emergency medicine. The ambulance driver-rescuers, who furnish first aid to the victims, are the non-medical part of the Italian 118-service staff. There is a lack of research on burnout risk in Italian Emergency Medical Services and, particularly, for this category of workers. The two Italian studies, including a little group of ambulance driver-rescuers, reported inconsistent findings. Hypothesis: This survey investigated for the first time the prevalence and exact profile of burnout in a large sample of Italian driver-rescuers. As a secondary aim, the study described how the items of the Italian version of the Maslach Burnout Inventory-Human Services Survey (MBI-HSS) cluster in components in this sample. Methods: This cross-sectional census survey was conducted from June 2015 through May 2016 and involved all the driver-rescuers operating in Sicily, the biggest and most southern region of Italy. The subjects received a classification according to different profiles of burnout by using the Italian version of the MBI-HSS (burnout, engagement, disengagement, over-extension, and work-inefficacy). In order to explore the existence of independent factors, a Principal Component Analysis (PCA) was conducted on the survey to obtain eigenvalues >one for each component in the data. Results: The final sample comprised 2,361 responders (96.6% of the initial sample). Of them, 29.8% were in burnout (95% confidence interval [CI], 27.8% to 31.8%) and 1.7% presented a severe form (95% CI, 1.1% to 2.3%); 30.0% were engaged in their work (95% CI, 21.0% to 34.8%), 24.7% of responders were disengaged (95% CI, 22.9% to 26.5%), 1.2% presented an over-extension profile (95% CI, 0.8% to 1.7%), and 12.6% felt work-inefficacy (95% CI, 11.3% to 14.1%). The factors loaded into a five-factor solution at PCA, explaining 48.1% of the variance and partially replicating the three-factor structure. The Emotional Exhaustion (EE) component was confirmed. New dimensions from Personal Accomplishment (PA) and Depersonalization (DP) sub-scales described empathy and disengagement with patients, respectively, and were responsible for the increased risk of burnout. Conclusions: These results endorse the importance of screening and psychological interventions for this population of emergency workers, where burnout could manifest itself more insidiously. It is also possible to speculate that sub-optimal empathy skills could be related to the disengagement and work-inefficacy feelings registered

    “Evidence-Based Dentistry in Oral Surgery: Could We Do Better?”

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    Evidence-based Dentistry (EBD), like Evidence-based Medicine (EBM), was born in order to seek the “best available research evidence” in the field of dentistry both in research and clinical routine
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