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https://www.readbyqxmd.com/read/28214272/fungal-monitoring-of-the-indoor-air-of-the-museo-de-la-plata-herbarium-argentina
#1
Andrea C Mallo, Lorena A Elíades, Daniela S Nitiu, Mario C N Saparrat
BACKGROUND: Biological agents, such as fungal spores in the air in places where scientific collections are stored, can attack and deteriorate them. AIMS: The aim of this study was to gather information on the indoor air quality of the Herbarium of Vascular Plants of the Museo de Ciencias Naturales de La Plata, Argentina, in relation to fungal propagules and inert particles. METHODS: This study was made using a volumetric system and two complementary sampling methods: (1) a non-viable method for direct evaluation, and (2) a viable method by culture for viable fungal propagules...
February 14, 2017: Revista Iberoamericana de Micología
https://www.readbyqxmd.com/read/28211328/excretion-characteristics-of-tetrabromobisphenol-a-in-wistar-rats-following-mouth-and-nose-inhalation-exposure
#2
Yunjiang Yu, Zhengdong Wang, Qiong Wang, Mingdeng Xiang, Yanping Zhang, Qingzhi Ge, Liangzhong Li, Hui Li, Ruixue Ma
Tetrabromobisphenol-A (TBBPA), a brominated flame retardant with the largest production volume worldwide, is employed as a reactive and additive flame retardant, and also as an intermediate in the production of other retardants. The constant release of TBBPA into the environment has attracted increasing attention to its potent health effects. To date, the vast majority of health-related research on TBBPA has focused on oral exposure. This study aims to explore the excretion characteristics of TBBPA in living organisms following inhalation exposure...
February 4, 2017: Chemosphere
https://www.readbyqxmd.com/read/28201870/self-organization-induced-by-self-assembly-in-microheterogeneous-reaction-diffusion-system
#3
Alexander A Cherkashin, Vladimir K Vanag
When acrylamide (AA) monomers are added to the Belousov-Zhabotinsky (BZ) reaction incorporated into nanodroplets of water-in-oil aerosol OT (AOT) microemulsion (the BZ-AOT system), free radicals produced in the BZ reaction initiate polymerization of AA monomers and polyacrylamide particles are formed. These particles change the microstructure of the AOT microemulsion thus inducing the transition from Turing patterns to new dissipative patterns which can be either stationary "black" spots or waves.
February 15, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28199945/contribution-of-methane-sulfonic-acid-to-new-particle-formation-in-the-atmosphere
#4
Hailiang Zhao, Xiaotong Jiang, Lin Du
Methane sulfonic acid (MSA) is present in substantial concentrations in the gas phase over oceans and coastal regions. We present an investigation into the contribution of MSA to new particle formation with the common atmospheric aerosol nucleation precursors including MSA, methanol, formic acid, acetone, dimethylether, formaldehyde, methyl formate, by making use a quantum chemical approach. Density functional theory calculations indicate that these bimolecular complexes are characterized by the presence of strong inter-molecular hydrogen bonds (SOH⋯O) with large binding energies and thermodynamic equilibrium constants...
February 7, 2017: Chemosphere
https://www.readbyqxmd.com/read/28197614/characterization-of-the-temperature-and-humidity-dependent-phase-diagram-of-amorphous-nanoscale-organic-aerosols
#5
Nicholas E Rothfuss, Markus D Petters
Atmospheric aerosols can exist in amorphous semi-solid or glassy phase states. These states are determined by the temperature (T) and relative humidity (RH). New measurements of viscosity for amorphous semi-solid nanometer size sucrose particles as a function of T and RH are reported. Viscosity is measured by inducing coagulation between two particles and probing the thermodynamic states that induce the particle to relax into a sphere. It is shown that the glass transition temperature can be obtained by extrapolation to 10(12) Pa s from the measured temperature-dependent viscosity in the 10(6) to 10(7) Pa s range...
February 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28197606/the-properties-and-behavior-of-%C3%AE-pinene-secondary-organic-aerosol-particles-exposed-to-ammonia-under-dry-conditions
#6
David M Bell, Dan Imre, Scot T Martin, Alla Zelenyuk
Chemical transformations and aging of secondary organic aerosol (SOA) particles can alter their physical and chemical properties, including particle morphology. Ammonia, one of the common atmospheric reactive constituents, can react with SOA particles, changing their properties and behavior. At low relative humidity, NH3 uptake by α-pinene SOA particles appears to be limited to the particle surface, which suggests that the reacted particles might not be homogeneous and have complex morphology. Here, we present a study aimed at detailed characterization of the effect of ammonia on the composition, density, morphology, shape, and evaporation kinetics of α-pinene SOA particles...
February 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28195722/effects-of-relative-humidity-and-particle-phase-water-on-the-heterogeneous-oh-oxidation-of-2-methylglutaric-acid-aqueous-droplets
#7
Man Mei Chim, Chun Yin Chow, James F Davies, ManNin Chan
Organic aerosols can exist as aqueous droplets, with variable water content depending on their composition and environmental conditions (e.g. relative humidity (RH)). Recent laboratory studies have revealed that oxidation kinetics in highly concentrated droplets can be much slower from those in dilute solutions. However, it remains unclear whether particle phase water affects the formation of reaction products physically and/or chemically. In this work, we investigate the role of particle phase water on the heterogeneous chemistry of aqueous organic droplets consisting of 2-methylglutaric acid (2-MGA), measuring the reaction kinetics and the reaction products upon heterogeneous OH oxidation over a range of RH...
February 14, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28194981/droplet-assisted-inlet-ionization-for-online-analysis-of-airborne-nanoparticles
#8
Andrew J Horan, Michael J Apsokardu, Murray V Johnston
Airborne nanoparticles play a key role in climate effects as well as impacting human health. Their small mass and complex chemical composition represent significant challenges for analysis. This work introduces a new ionization method, droplet assisted inlet ionization (DAII), where aqueous droplets are produced from airborne nanoparticles. When these droplets enter the mass spectrometer through a heated inlet, rapid vaporization leads to the formation of molecular ions. The method is demonstrated with test aerosols consisting of polypropylene glycol (PPG), angiotensin II, bovine serum albumin, and the "thermometer" compound p-methoxybenzylpyridinium chloride...
January 17, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28194674/biomonitoring-of-atmospheric-pollution-a-novel-approach-for-the-evaluation-of-natural-and-anthropogenic-contribution-to-atmospheric-aerosol-particles
#9
Rosa Caggiano, Giuseppe Calamita, Serena Sabia, Serena Trippetta
The investigation of the potential natural and anthropogenic contribution to atmospheric aerosol particles by using lichen-bag technique was performed in the Agri Valley (Basilicata region, southern Italy). This is an area of international concern since it houses one of the largest European on-shore reservoirs and the biggest oil/gas pre-treatment plant (i.e., Centro Olio Val d'Agri (COVA)) within an anthropized context. In particular, the concentrations of 17 trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Ti, and Zn) were measured in lichen bags exposed in 59 selected monitoring points over periods of 6 months (from October 2011 to April 2012) and 12 months (from October 2011 to October 2012)...
February 13, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28192926/mass-spectrometry-characterization-of-peroxycarboxylic-acids-as-proxies-for-reactive-oxygen-species-and-highly-oxygenated-molecules-in-atmospheric-aerosols
#10
Sarah S Steimer, Ivan Kourtchev, Markus Kalberer
A significant fraction of atmospheric aerosol particles is composed of organic material with a highly complex but poorly characterized composition. For a better understanding of aerosol effects and processes in the atmosphere, a more detailed knowledge of aerosol components at a molecular level is needed. Peroxy acids might play a significant role in particle toxicity, due to their oxidizing properties, and they were recently found to be involved in particle formation. Because of the lack of appropriate standards, the identification and quantification of peroxy acids is often highly uncertain...
February 10, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28190686/role-of-snow-in-the-fate-of-gaseous-and-particulate-exhaust-pollutants-from-gasoline-powered-vehicles
#11
Yevgen Nazarenko, Sébastien Fournier, Uday Kurien, Rodrigo Benjamin Rangel-Alvarado, Oleg Nepotchatykh, Patrice Seers, Parisa A Ariya
Little is known about pollution in urban snow and how aerosol and gaseous air pollutants interact with the urban snowpack. Here we investigate interactions of exhaust pollution with snow at low ambient temperature using fresh snow in a temperature-controlled chamber. A gasoline-powered engine from a modern light duty vehicle generated the exhaust and was operated in homogeneous and stratified engine regimes. We determined that, within a timescale of 30 min, snow takes up from the exhaust a large mass of organic pollutants and aerosol particles, which were observed by electron microscopy, mass spectrometry and aerosol sizers...
February 9, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28187746/slow-lung-clearance-and-limited-translocation-of-four-sizes-of-inhaled-iridium-nanoparticles
#12
Alison Buckley, James Warren, Alan Hodgson, Tim Marczylo, Konstantin Ignatyev, Chang Guo, Rachel Smith
BACKGROUND: Concerns have been expressed that inhaled nanoparticles may behave differently to larger particles in terms of lung clearance and translocation, with potential implications for their toxicity. Studies undertaken to investigate this have typically involved limited post-exposure periods. There is a shortage of information on longer-term clearance and translocation patterns and their dependence on particle size, which this study aimed to address. METHODS: Rats were exposed (<3 h) nose-only to aerosols of spark-generated radioactive iridium-192 nanoparticles of four sizes: 10 nm, 15 nm, 35 nm and 75 nm (count median diameter) (aerosol mass concentrations 17, 140, 430, and 690 μg/m(3), respectively)...
February 10, 2017: Particle and Fibre Toxicology
https://www.readbyqxmd.com/read/28187383/characterization-of-the-ambient-air-content-of-parent-polycyclic-aromatic-hydrocarbons-in-the-fort-mckay-region-canada
#13
Andrzej Wnorowski
This study presents the characterization of the gas-particle partition and size distribution of seven parent polycyclic aromatic hydrocarbons (PAHs) in ambient air samples collected in the proximity of oil sands exploration and compares their time-integrated concentration levels with nineteen analogous oxidation products - quinones. Gas-phase (GP) and particle-phase (PM) ambient air aerosol samples that were collected separately in summer for either 24 h or 12 h (day and night) revealed a higher PAH partition in the GP than in the PM, with the distribution over tenfold higher for light over heavy PAHs...
January 25, 2017: Chemosphere
https://www.readbyqxmd.com/read/28181839/anhydrous-reverse-micelle-nanoparticles-new-strategy-to-overcome-sedimentation-instability-of-peptide-containing-pressurized-metered-dose-inhalers
#14
Zhengwei Huang, Han Wu, Beibei Yang, Longkai Chen, Ying Huang, Guilan Quan, Chune Zhu, Xing Li, Xin Pan, Chuanbin Wu
The objective of this study was to develop a novel anhydrous reverse micelle nanoparticles (ARM-NPs) system to overcome the sedimentation instability of peptide-containing pressurized metered-dose inhalers (pMDIs). A bottom-up method was utilized to fabricate ARM-NPs. Tertiary butyl alcohol (TBA)/water system, freeze-drying and lipid inversion method were successively used to produce the ARM-NPs for pMDI. Various characteristics of ARM-NPs were investigated including particle size, morphology, secondary structure of the peptide drug, aerosolization properties and storage stability...
November 2017: Drug Delivery
https://www.readbyqxmd.com/read/28181520/novel-concept-for-neutron-detection-proportional-counter-filled-with-10-b-nanoparticle-aerosol
#15
F D Amaro, C M B Monteiro, J M F Dos Santos, A Antognini
The high neutron detection efficiency, good gamma-ray discrimination and non-toxicity of (3)He made of proportional counters filled with this gas the obvious choice for neutron detection, particularly in radiation portal monitors (RPM), used to control the illicit transport of nuclear material, of which neutron detectors are key components. (3)He is very rare and during the last decade this gas has become increasingly difficult to acquire. With the exception of BF3, which is toxic, no other gas can be used for neutron detection in proportional counters...
February 9, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28161667/aerodynamic-properties-and-in-silico-deposition-of-meloxicam-potassium-incorporated-in-a-carrier-free-dpi-pulmonary-system
#16
Anita Chvatal, Árpád Farkas, Imre Balásházy, Piroska Szabó-Révész, Rita Ambrus
Dry powder inhalers (DPIs) have been among the fastest developing inhaler forms in the past decades. Researches are focusing on the formulation of carrier-free powders to obtain a higher deep-lung deposition and hereby to increase the effectiveness of the medicine. The aim of our study was to prepare a carrier-free dry powder formulation of meloxicam potassium (MP), a novel salt form of meloxicam, using a one-step co-spray drying technology. Different types of excipients were used to modify the crystal structure and to increase aerosolization efficacy...
February 1, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28160538/fine-and-ultrafine-aerosol-in-ostrava-ambient-air
#17
Karel Lach, Karel Klouda, Vladimír Mička, Lucie Hellebrandová
Air quality in the Moravian-Silesian Region and especially in the Ostrava agglomeration represents a very important factor influencing the environment and health of the local population. The area has been burdend for more than two centuries with rapid development of the mining industry and related metallurgical and chemical production. As a result, hundreds of tons of pollutants have progressively been released into the atmosphere. Some of them have been gradually eliminated from the environment; others, such as some heavy metals, remain locally present and burden the local landscape...
December 2016: Central European Journal of Public Health
https://www.readbyqxmd.com/read/28159683/measurement-of-the-raman-spectra-and-hygroscopicity-of-four-pharmaceutical-aerosols-as-they-travel-from-pressurised-metered-dose-inhalers-pmdi-to-a-model-lung
#18
N Davidson, H-J Tong, M Kalberer, P C Seville, A D Ward, M K Kuimova, F D Pope
Particle inhalation is an effective and rapid delivery method for a variety of pharmaceuticals, particularly bronchodilation drugs used for treating asthma and COPD. Conditions of relative humidity and temperature inside the lungs are generally very different from the outside ambient air, with the lung typically being warmer and more humid. Changes in humidity, from inhaler to lung, can cause hygroscopic phase transitions and particle growth. Increasing particle size and mass can negatively affect particle deposition within the lung leading to inefficient treatment, while deliquescence prior to impaction is liable to accelerate drug uptake...
January 31, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28158028/light-scattering-computation-model-for-nonspherical-aerosol-particles-based-on-multi-resolution-time-domain-scheme-model-development-and-validation
#19
Shuai Hu, Taichang Gao, Hao Li, Bo Yang, Feng Zhang, Ming Chen, Lei Liu
Due to the inadequate understanding of the scattering properties of nonspherical aerosols, considerable uncertainties still exist in the radiative transfer numerical simulation. To this end, a new scattering model for nonspherical aerosols is established based on Multi-Resolution Time-Domain (MRTD) scheme. The model is comprised of three modules: near field calculation module, near-to-far transformation module and scattering parameters computation module, in which, the near electromagnetic field is calculated by MRTD technique, the near-to-far transformation scheme is performed by volume integral method, and the calculation models for extinction and absorption cross section are directly derived from Maxwell's curl equations in the frequency domain...
January 23, 2017: Optics Express
https://www.readbyqxmd.com/read/28157859/measurement-of-back-scattering-patterns-from-single-laser-trapped-aerosol-particles-in-air
#20
Yong-Le Pan, Chuji Wang, Leonid A Beresnev, Alex J Yuffa, Gorden Videen, David Ligon, Joshua L Santarpia
We demonstrate a method for measuring elastic back-scattering patterns from single laser trapped micron-sized particles, spanning the scattering angle range of θ=167.7°-180° and φ=0°-360° in spherical coordinates. We calibrated the apparatus by capturing light-scattering patterns of 10 μm diameter borosilicate glass microspheres and comparing their scattered intensities with Lorenz-Mie theory. Back-scattering patterns are also presented from a single trapped Johnson grass spore, two attached Johnson grass spores, and a cluster of Johnson grass spores...
January 20, 2017: Applied Optics
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