Search results for "Aerosols"
showing 10 items of 105 documents
Évaluation des risques relatifs aux mesures de décontamination et de gestion des sous-produits animaux lors des cas de botulisme bovin et aviaire
2022
Le botulisme est une maladie neurologique humaine et animale, le plus souvent d’origine alimentaire, provoquée par l’action de neurotoxines bactériennes (toxines botuliques) produites par la bactérie Clostridium botulinum et qui se manifeste par une paralysie flasque pouvant aller jusqu’à la paralysie respiratoire et l’arrêt cardiaque. Neuf types toxiniques, répartis en une quarantaine de sous-types, sont actuellement connus.En France, le botulisme animal affecte essentiellement les oiseaux (sauvages et domestiques) et les bovins. Chez les volailles, on recense annuellement vingt à trente foyers, majoritairement dus aux types mosaïque C/D (élevages de poulets de chair et de dindes) suivi de…
Anti-tumor activity of CpG-ODN aerosol in mouse lung metastases
2013
Studies in preclinical models have demonstrated the superior anti-tumor effect of CpG oligodeoxynucleotides (CpG-ODN) when administered at the tumor site rather than systemically. We evaluated the effect of aerosolized CpG-ODN on lung metastases in mice injected with immunogenic N202.1A mammary carcinoma cells or weakly immunogenic B16 melanoma cells. Upon reaching the bronchoalveolar space, aerosolized CpG-ODN activated a local immune response, as indicated by production of IL-12p40, IFN-γ and IL-1β and by recruitment and maturation of DC cells in bronchoalveolar lavage fluid of mice. Treatment with aerosolized CpG-ODN induced an expansion of CD4+ cells in lung and was more efficacious tha…
Analysis of Organic Aerosols Using a Micro-Orifice Volatilization Impactor Coupled to an Atmospheric-Pressure Chemical Ionization Mass Spectrometer
2014
We present the development and characterization of a combination of a micro-orifice volatilization impactor (MOVI) and an ion trap mass spectrometer (IT/MS) with an atmospheric-pressure chemical ionization (APCI) source. The MOVI is a multi-jet impactor with 100 nozzles, allowing the collection of aerosol particles by inertial impaction on a deposition plate. The pressure drop behind the nozzles is approximately 5%, resulting in a pressure of 96 kPa on the collection surface for ambient pressures of 101.3 kPa. The cut-point diameter (diameter of 50% collection efficiency) is at 0.13 μm for a sampling flow rate of 10 L min–1. After the collection step, aerosol particles are evaporated by he…
Molecular Characterization and Source Identification of Atmospheric Particulate Organosulfates Using Ultrahigh Resolution Mass Spectrometry.
2019
Organosulfates (OSs) have been observed as substantial constituents of atmospheric organic aerosol (OA) in a wide range of environments; however, the chemical composition, sources, and formation mechanism of OSs are still not well understood. In this study, we first created an "OS precursor map" based on the elemental composition of previous OS chamber experiments. Then, according to this "OS precursor map", we estimated the possible sources and molecular structures of OSs in atmospheric PM2.5 (particles with aerodynamic diameter ≤ 2.5 μm) samples, which were collected in urban areas of Beijing (China) and Mainz (Germany) and analyzed by ultrahigh-performance liquid chromatography (UHPLC) c…
Radical Formation by Fine Particulate Matter Associated with Highly Oxygenated Molecules
2019
Highly oxygenated molecules (HOMs) play an important role in the formation and evolution of secondary organic aerosols (SOA). However, the abundance of HOMs in different environments and their relation to the oxidative potential of fine particulate matter (PM) are largely unknown. Here, we investigated the relative HOM abundance and radical yield of laboratory-generated SOA and fine PM in ambient air ranging from remote forest areas to highly polluted megacities. By electron paramagnetic resonance and mass spectrometric investigations, we found that the relative abundance of HOMs, especially the dimeric and low-volatility types, in ambient fine PM was positively correlated with the formatio…
IASI dataset v1
2020
The Infrared Atmospheric Sounding Interferometer (IASI) on board the MetOp satellite series measures the infrared spectrum with high resolution. The ground footprint resolution of the instruments is 12 km at nadir, and a spectral resolution of 0.25cm −1 in the spectrum between 645 cm −1 and 2760 cm −1 . This results in 8461 spectral samples covering 2200km scan-swath with 60 points per line. IASI is an ideal instrument for monitoring different physical/chemical parameters in the atmosphere e.g. temperature, humidity and trace gases such as ozone. Energy from different altitudes returns a different spectral shift. In this way atmospheric profiles can be obtained and these provides important …
The ACRIDICON-CHUVA campaign: Studying tropical deep convective clouds and precipitation over Amazonia using the new German research aircraft HALO
2016
Abstract Between 1 September and 4 October 2014, a combined airborne and ground-based measurement campaign was conducted to study tropical deep convective clouds over the Brazilian Amazon rain forest. The new German research aircraft, High Altitude and Long Range Research Aircraft (HALO), a modified Gulfstream G550, and extensive ground-based instrumentation were deployed in and near Manaus (State of Amazonas). The campaign was part of the German–Brazilian Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems–Cloud Processes of the Main Precipitation Systems in Brazil: A Contribution to Cloud Resolving Modeling and to the GPM (Global Precipitatio…
Alternative Methods of Sterilization in Dental Practices Against COVID-19
2020
SARS-CoV-2, and several other microorganisms, may be present in nasopharyngeal and salivary secretions in patients treated in dental practices, so an appropriate clinical behavior is required in order to avoid the dangerous spread of infections. COVID-19 could also be spread when patients touches a contaminated surface with infected droplets and then touch their nose, mouth, or eyes. It is time to consider a dental practice quite similar to a hospital surgery room, where particular attention should be addressed to problems related to the spreading of infections due to air and surface contamination. The effectiveness of conventional cleaning and disinfection procedures may be limited by seve…
Results from the Fourth WMO Filter Radiometer Comparison for aerosol optical depth measurements
2018
Abstract. This study presents the results of the Fourth Filter Radiometer Comparison that was held in Davos, Switzerland, between 28 September and 16 October 2015. Thirty filter radiometers and spectroradiometers from 12 countries participated including reference instruments from global aerosol networks. The absolute differences of all instruments compared to the reference have been based on the World Meteorological Organization (WMO) criterion defined as follows: 95% of the measured data has to be within 0.005 ± 0.001∕m (where m is the air mass). At least 24 out of 29 instruments achieved this goal at both 500 and 865 nm, while 12 out of 17 and 13 out of 21 achieved this at 368 and 412 nm,…
Characterization of the Etna volcanic emissions through an active biomonitoring technique (moss-bags): Part 2 – Morphological and mineralogical featu…
2013
Volcanic emissions were studied at Mount Etna (Italy) by using moss-bags technique. Mosses were exposed around the volcano at different distances from the active vents to evaluate the impact of volcanic emissions in the atmosphere. Morphology and mineralogy of volcanic particulate intercepted by mosses were investigated using scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS). Particles emitted during passive degassing activity from the two active vents, Bocca Nuova and North East Crater (BNC and NEC), were identified as silicates, sulfates and halide compounds. In addition to volcanic particles, we found evidences also of geogenic, anthropogenic and marin…