47 research outputs found

    Atypical presentation of juvenile multiple sclerosis in a patient with COVID-19

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    Purpose: To report our experience with a case of a very atypical clinical onset of multiple sclerosis in a young boy during a COVID-19 infection. Case report: A 16-year-old boy was referred to our ophthalmology clinic with a complete isolated bilateral horizontal gaze palsy. The condition had onset suddenly 2 weeks prior and he had no associated symptoms, as well as no significant medical history. His corrected visual acuity was 0.0 logMAR in both eyes. While hospitalized, he was found infected with COVID-19. Subsequent brain MRI showed multiple lesions typical of a yet undiagnosed MS, as well as an active pontine plaque which was highly probable the cause of the horizontal gaze palsy. High-dose steroid treatment was initiated 1 week later, after the patient exhibited negative COVID-19 test results. Conclusion: Clinical manifestations of MS are rarely seen in male teenagers and only a few cases of isolated bilateral horizontal gaze palsy have been reported as the initial manifestation, but never during concomitant COVID-19 infection. We presume that the presence of COVID-19 may have been a neuroinflammatory trigger of underlying MS

    The Outcome of Cholangitis After Percutaneous Biliary Drainage in Neoplastic Jaundice

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    The purpose of this paper is to evaluate factors affecting the outcome of cholangitis after PTBD in jaundiced cancer patients. Twenty nine patients with neoplastic jaundice (male/female ratio 13/16, median age 55 years) with full clinical data, were treated by PTBD and developed cholangitis at a median of 9 days later. Four patients (14%) died of biliary sepsis a median of one month after PTBD while the other 25 survived a median of 6 months, with one week median duration of cholangitis. The probability of the cholangitis resolving was analyzed by time to resolution and it was found that 50% and 100% of the recoveries occurred 5 and 9 months respectively from the onset of the complication

    Indoor terpene emissions from cooking with herbs and pepper and their secondary organic aerosol production potential

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    Cooking is widely recognized as an important source of indoor and outdoor particle and volatile organic compound emissions with potential deleterious effects on human health. Nevertheless, cooking emissions remain poorly characterized. Here the effect of herbs and pepper on cooking emissions was investigated for the first time to the best of our knowledge using state of the art mass spectrometric analysis of particle and gas-phase composition. Further, the secondary organic aerosol production potential of the gas-phase emissions was determined by smog chamber aging experiments. The emissions of frying meat with herbs and pepper include large amounts of mono-, sesqui- and diterpenes as well as various terpenoids and p-cymene. The average total terpene emission rate from the use of herbs and pepper during cooking is estimated to be 46 ± 5 gg-1 Herbs min-1. These compounds are highly reactive in the atmosphere and lead to significant amounts of secondary organic aerosol upon aging. In summary we demonstrate that cooking with condiments can constitute an important yet overlooked source of terpenes in indoor air

    Characterization of Gas-Phase Organics Using Proton Transfer Reaction Time-of-Flight Mass Spectrometry : Cooking Emissions

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    Cooking processes produce gaseous and particle emissions that are potentially deleterious to human health. Using a highly controlled experimental setup involving a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), we investigate the emission factors and the detailed chemical composition of gas phase emissions from a broad variety of cooking styles and techniques. A total of 95 experiments were conducted to characterize nonmethane organic gas (NMOG) emissions from boiling, charbroiling, shallow frying, and deep frying of various vegetables and meats, as well as emissions from vegetable oils heated to different temperatures. Emissions from boiling vegetables are dominated by methanol. Significant amounts of dimethyl sulfide are emitted from cruciferous vegetables. Emissions from shallow frying, deep frying and charbroiling are dominated by aldehydes of differing relative composition depending on the oil used. We show that the emission factors of some aldehydes are particularly large which may result in considerable negative impacts on human health in indoor environments. The suitability of some of the aldehydes as tracers for the identification of cooking emissions in ambient air is discussed

    Large contribution of fossil fuel derived secondary organic carbon to water soluble organic aerosols in winter haze in China

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    Water-soluble organic carbon (WSOC) is a large fraction of organic aerosols (OA) globally and has significant impacts on climate and human health. The sources of WSOC remain very uncertain in polluted regions. Here we present a quantitative source apportionment of WSOC, isolated from aerosols in China using radiocarbon (14C) and offline high-resolution time-of-flight aerosol mass spectrometer measurements. Fossil emissions on average accounted for 32–47% of WSOC. Secondary organic carbon (SOC) dominated both the non-fossil and fossil derived WSOC, highlighting the importance of secondary formation to WSOC in severe winter haze episodes. Contributions from fossil emissions to SOC were 61±4 and 50±9% in Shanghai and Beijing, respectively, significantly larger than those in Guangzhou (36±9 %) and Xi’an (26±9 %). The most important primary sources were biomass burning emissions, contributing 17–26% of WSOC. The remaining primary sources such as coal combustion, cooking and traffic were generally very small but not negligible contributors, as coal combustion contribution could exceed 10 %. Taken together with earlier 14C source apportionment studies in urban, rural, semi-urban and background regions in Asia, Europe and the USA, we demonstrated a dominant contribution of non-fossil emissions (i.e., 75±11 %) to WSOC aerosols in the Northern Hemisphere; however, the fossil fraction is substantially larger in aerosols from East Asia and the eastern Asian pollution outflow, especially during winter, due to increasing coal combustion. Inclusion of our findings can improve a modelling of effects of WSOC aerosols on climate, atmospheric chemistry and public health

    ACTRIS ACSM intercomparison – Part 2: Intercomparison of ME-2 organic source apportionment results from 15 individual, co-located aerosol mass spectrometers

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    Chemically resolved atmospheric aerosol data sets from the largest intercomparison of the Aerodyne aerosol chemical speciation monitors (ACSMs) performed to date were collected at the French atmospheric supersite SIRTA. In total 13 quadrupole ACSMs (Q-ACSM) from the European ACTRIS ACSM network, one time-of-flight ACSM (ToF-ACSM), and one high-resolution ToF aerosol mass spectrometer (AMS) were operated in parallel for about 3 weeks in November and December~2013. Part 1 of this study reports on the accuracy and precision of the instruments for all the measured species. In this work we report on the intercomparison of organic components and the results from factor analysis source apportionment by positive matrix factorisation (PMF) utilising the multilinear engine 2 (ME-2). Except for the organic contribution of mass-to-charge ratio m/z 44 to the total organics (f44), which varied by factors between 0.6 and 1.3 compared to the mean, the peaks in the organic mass spectra were similar among instruments. The m/z 44 differences in the spectra resulted in a variable f44 in the source profiles extracted by ME-2, but had only a minor influence on the extracted mass contributions of the sources. The presented source apportionment yielded four factors for all 15 instruments: hydrocarbon-like organic aerosol (HOA), cooking-related organic aerosol (COA), biomass burning-related organic aerosol (BBOA) and secondary oxygenated organic aerosol (OOA). ME-2 boundary conditions (profile constraints) were optimised individually by means of correlation to external data in order to achieve equivalent / comparable solutions for all ACSM instruments and the results are discussed together with the investigation of the influence of alternative anchors (reference profiles). A comparison of the ME-2 source apportionment output of all 15 instruments resulted in relative standard deviations (SD) from the mean between 13.7 and 22.7 % of the source's average mass contribution depending on the factors (HOA: 14.3 ± 2.2 %, COA: 15.0 ± 3.4 %, OOA: 41.5 ± 5.7 %, BBOA: 29.3 ± 5.0 %). Factors which tend to be subject to minor factor mixing (in this case COA) have higher relative uncertainties than factors which are recognised more readily like the OOA. Averaged over all factors and instruments the relative first SD from the mean of a source extracted with ME-2 was 17.2 %.JRC.H.2-Air and Climat

    Organic aerosol source apportionment by offline-AMS over a full year in Marseille

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    We investigated the seasonal trends of OA sources affecting the air quality of Marseille (France), which is the largest harbor of the Mediterranean Sea. This was achieved by measurements of nebulized filter extracts using an aerosol mass spectrometer (offline-AMS). In total 216 PM2.5 (particulate matter with an aerodynamic diameter < 2.5 μm) filter samples were collected over 1 year from August 2011 to July 2012. These filters were used to create 54 composite samples which were analyzed by offline-AMS. The same samples were also analyzed for major water-soluble ions, metals, elemental and organic carbon (EC/OC), and organic markers, including n-alkanes, hopanes, polycyclic aromatic hydrocarbons (PAHs), lignin and cellulose pyrolysis products, and nitrocatechols. The application of positive matrix factorization (PMF) to the water-soluble AMS spectra enabled the extraction of five factors, related to hydrocarbon-like OA (HOA), cooking OA (COA), biomass burning OA (BBOA), oxygenated OA (OOA), and an industry-related OA (INDOA). Seasonal trends and relative contributions of OA sources were compared with the source apportionment of OA spectra collected from the AMS field deployment at the same station but in different years and for shorter monitoring periods (February 2011 and July 2008). Online- and offline-AMS source apportionment revealed comparable seasonal contribution of the different OA sources. Results revealed that BBOA was the dominant source during winter, representing on average 48 % of the OA, while during summer the main OA component was OOA (63 % of OA mass on average). HOA related to traffic emissions contributed on a yearly average 17 % to the OA mass, while COA was a minor source contributing 4 %. The contribution of INDOA was enhanced during winter (17 % during winter and 11 % during summer), consistent with an increased contribution from light alkanes, light PAHs (fluoranthene, pyrene, phenanthrene), and selenium, which is commonly considered as a unique coal combustion and coke production marker. Online- and offline-AMS source apportionments revealed evolving levoglucosan : BBOA ratios, which were higher during late autumn and March. A similar seasonality was observed in the ratios of cellulose combustion markers to lignin combustion markers, highlighting the contribution from cellulose-rich biomass combustion, possibly related to agricultural activities. © 2017 Author(s).Acknowledgements. Carlo Bozzetti thanks the Lithuanian–Swiss Cooperation Programme “Research and Development” project AEROLIT (no. CH-3-.MM-01/08). Jay Gates Slowik acknowledges the support of the Swiss National Science Foundation (starting grant no. BSSGI0 155846). Imad El Haddad acknowledges the support of the Swiss National Science Foundation (IZERZ0 142146). María Cruz Minguillón acknowledges the Ramón y Cajal Fellowship awarded by the Spanish Ministry of Economy, Industry and Competitiveness. This work has also been supported by the MED program (APICE, grant number 2G-MED09-026: http://www.apice-project.eu/), the French Environment and Energy Management Agency (ADEME), and Provence-Alpes-Côte d’Azur (PACA) region. Part of the OC/ EC analysis carried out in MRS was supported by the French national CARA program. This program is directed by Olivier Favez (INERIS; http://www.ineris.fr/). He is gratefully acknowledged.Peer reviewe
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