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aerosol particle

Pyeong-Koo Lee, Soonyoung Yu, Hye Jung Chang, Hye Young Cho, Min-Ju Kang, Byung-Gon Chae
Spherical black carbon aggregates were frequently observed in dust dry deposition in Daejeon, Korea. They were tens of micrometers in diameter and presented a mixture of black carbon and several mineral phases. Transmission electron microscopy (TEM) observations with energy-dispersive X-ray spectroscopy (EDS) and selected area diffraction pattern (SADP) analyses confirmed that the aggregates were compact and included significant amounts of lead chromate (PbCrO4). The compositions and morphologies of the nanosized lead chromate particles suggest that they probably originated from traffic paint used in roads and were combined as discrete minerals with black carbon...
October 25, 2016: Scientific Reports
Jian Wang, Radovan Krejci, Scott Giangrande, Chongai Kuang, Henrique M J Barbosa, Joel Brito, Samara Carbone, Xuguang Chi, Jennifer Comstock, Florian Ditas, Jost Lavric, Hanna E Manninen, Fan Mei, Daniel Moran-Zuloaga, Christopher Pöhlker, Mira L Pöhlker, Jorge Saturno, Beat Schmid, Rodrigo A F Souza, Stephen R Springston, Jason M Tomlinson, Tami Toto, David Walter, Daniela Wimmer, James N Smith, Markku Kulmala, Luiz A T Machado, Paulo Artaxo, Meinrat O Andreae, Tuukka Petäjä, Scot T Martin
The nucleation of atmospheric vapours is an important source of new aerosol particles that can subsequently grow to form cloud condensation nuclei in the atmosphere. Most field studies of atmospheric aerosols over continents are influenced by atmospheric vapours of anthropogenic origin (for example, ref. 2) and, in consequence, aerosol processes in pristine, terrestrial environments remain poorly understood. The Amazon rainforest is one of the few continental regions where aerosol particles and their precursors can be studied under near-natural conditions, but the origin of small aerosol particles that grow into cloud condensation nuclei in the Amazon boundary layer remains unclear...
October 24, 2016: Nature
Wan-Yi Li, Xia Li, Steffen Jockusch, Han Wang, Bolei Xu, Yajing Wu, William Gang Tsui, Hai-Lung Dai, V Faye McNeill, Yi Rao
Photoactivated reactions of organic species in atmospheric aerosol particles are a potentially significant source of secondary organic aerosol material (SOA). Despite recent progress, the dominant chemical mechanisms and rates of these reactions remain largely unknown. In this work, we characterize the photo-physical properties and photochemical reaction mechanisms of imidazole-2-carboxaldehyde (IC) in aqueous solution, alone and in the presence of isoprene. IC has been shown previously in laboratory studies to participate in photoactivated chemistry in aerosols, and is a known in-particle reaction product of glyoxal...
October 24, 2016: Journal of Physical Chemistry. A
Priya Muralidharan, Don Hayes, Stephen M Black, Heidi M Mansour
This systematic and comprehensive study reports for the first time on the successful rational design of advanced inhalable therapeutic dry powders containing dimethyl fumarate, a first-in-class Nrf2 activator drug to treat pulmonary inflammation, using particle engineering design technology for targeted delivery to the lungs as advanced spray dried (SD) one-component DPIs. In addition, two-component co-spray dried (co-SD) DMF:D-Man DPIs with high drug loading were successfully designed for targeted lung delivery as advanced DPIs using organic solution advanced spray drying in closed mode...
2016: Mol Syst Des Eng
Xiang Li, Timothy R Dallmann, Andrew A May, Daniel S Tkacik, Andrew T Lambe, John T Jayne, Philip L Croteau, Albert A Presto
We measured the gas-particle partitioning of vehicle emitted primary organic aerosol (POA) in a traffic tunnel with three independent methods: artifact corrected bare-quartz filters, thermodenuder (TD) measurements, and thermal-desorption gas-chromatography mass-spectrometry (TD-GC-MS). Results from all methods consistently show that vehicle emitted POA measured in the traffic tunnel is semivolatile under a wide range of fleet compositions and ambient conditions. We compared the gas-particle partitioning of POA measured in both tunnel and dynamometer studies and found that volatility distributions measured in the traffic tunnel are similar to volatility distributions measured in the dynamometer studies, and predict similar gas-particle partitioning in the TD...
October 20, 2016: Environmental Science & Technology
Daniela Pelclova, Vladimir Zdimal, Petr Kacer, Martin Komarc, Zdenka Fenclova, Stepanka Vlckova, Nadezda Zikova, Jaroslav Schwarz, Otakar Makes, Tomas Navratil, Sergey Zakharov, Dhimiter Bello
Nanoscale titanium dioxide (nanoTiO2) is a commercially important nanomaterial used in numerous applications. Experimental studies with nanotitania have documented lung injury and inflammation, oxidative stress, and genotoxicity. Production workers in TiO2 manufacturing with a high proportion of nanoparticles and a mixture of other air pollutants, such as gases and organic aerosols, had increased markers of oxidative stress, including DNA and protein damage, as well as lipid peroxidation in their exhaled breath condensate (EBC) compared to unexposed controls...
October 18, 2016: Reviews on Environmental Health
Suvajyoti Guha, Brady McCaffrey, Prasanna Hariharan, Matthew R Myers
Surgical respirators, surgical masks (SMs) and facemasks for pediatric use (FPUs) are routinely used in the US healthcare industry as personal protective equipment (PPE) against infectious diseases. While N95s including surgical respirators have been routinely studied, SMs and FPUs have not received as much attention, particularly in the context of aerosolized threats. This is because SMs and PFUs are not designed to protect against sub-micron aerosols. However, with the possibility of new or re-emerging airborne diseases or bio-aerosol weapons lingering, combined with the limited availability of respirators and logistical issues associated with fit-testing millions, the general adult and pediatric populations may elect to wear SMs and FPUs, respectively, in the case of a pandemic or a bio-terrorist attack...
October 18, 2016: Journal of Occupational and Environmental Hygiene
Benny Feng, Patricia Tang, Sharon Shui Yee Leung, Jayesh Dhanani, Hak-Kim Chan
BACKGROUND: Mechanically ventilated patients commonly suffer from ventilator-associated pneumonia, hypoxemia, and other lower respiratory tract infection as a result of pathogen colonization and poor sputum clearance. Consequently, there is a high rate of morbidity and mortality in these patients. Dry powder mannitol increases sputum clearance, and therefore, we developed a system to administer it to mechanically ventilated patients without disconnection from the ventilator. METHODS: The inspiratory line from a ventilator was split by using a three-way valve into two parallel lines where one contains a humidifier for normal breathing cycle and the other line contains a dry powder inhaler (Osmohaler™)...
October 18, 2016: Journal of Aerosol Medicine and Pulmonary Drug Delivery
Mingjie Kang, Pingqing Fu, Shankar G Aggarwal, Sudhanshu Kumar, Ye Zhao, Yele Sun, Zifa Wang
Size-segregated aerosol samples were collected in New Delhi, India from March 6 to April 6, 2012. Homologous series of n-alkanes (C19C33), n-fatty acids (C12C30) and n-alcohols (C16C32) were measured using gas chromatography/mass spectrometry. Results showed a high-variation in the concentrations and size distributions of these chemicals during non-haze, haze, and dust storm days. In general, n-alkanes, n-fatty acids and n-alcohols presented a bimodal distribution, peaking at 0.7-1.1 μm and 4.7-5.8 μm for fine modes and coarse modes, respectively...
October 14, 2016: Environmental Pollution
Jin Zhou, Wenjuan Fang, Qingliang Cao, Linyan Yang, Victor W-C Chang, William W Nazaroff
Utilizing the ultraviolet-light induced fluorescence (UV-LIF) measurement technique as embodied in the Waveband-Integrated Bioaerosol Sensor (WIBS-4A), we evaluated the fluorescent particle emissions associated with human shedding while walking in a chamber. The mean emission rates of supermicron (1-10 μm) fluorescent particles was in the range 6.8-7.5 million particles per person-h (~ 0.3 mg per person-h) across three participants, for conditions when the relative humidity was 60-70% and no moisturizer was applied after showering...
October 17, 2016: Indoor Air
Min Zhou, Liping Qiao, Shuhui Zhu, Li Li, Shengrong Lou, Hongli Wang, Qian Wang, Shikang Tao, Cheng Huang, Changhong Chen
In this work, a one-year observation focusing on high time resolution characteristics of components in fine particles was conducted at an urban site in Shanghai. Contributions of different components on visibility impairment were also studied. Our research indicates that the major components of PM2.5 in Shanghai are water-soluble inorganic ions and carbonaceous aerosol, accounting for about 60% and 30% respectively. Higher concentrations of sulfate (SO4(2-)) and organic carbon (OC) in PM2.5 occurred in fall and summer, while higher concentrations of nitrate (NO3(-)) were observed in winter and spring...
October 2016: Journal of Environmental Sciences (China)
Xiaoru Zhang, Yan Yin, Zhenyi Lin, Yongxiang Han, Jian Hao, Liang Yuan, Kui Chen, Jinghua Chen, Shaofei Kong, Yunpeng Shan, Hui Xiao, Wen Tan
To quantify the physical/chemical properties, and the formation and growth processes of aerosol particles on mountainous regions in Southeast China, an intensive field campaign was conducted from April to July 2008 on the top of Mt. Huang (1840m above mean sea level). The average particle number concentration was 2.35×10(3)cm(-3), and the ultrafine particles (<0.1μm) represented 70.5% of the total particle number concentration. Excluding the accumulation mode particles, the average daytime particle number concentrations were prominently higher than those measured at nighttime, suggesting there was a diurnal pattern of changes between planetary boundary layer and free troposphere air...
October 12, 2016: Science of the Total Environment
Per Bäckman, Ulrika Tehler, Bo Olsson
BACKGROUND: Exposure following oral inhalation depends on the deposition pattern of the inhaled aerosol, the extent and rate of oral and pulmonary absorption, as well as systemic distribution and clearance. For lipophilic inhaled compounds with low water solubility and high permeability, the extent and rate of pulmonary absorption can be assumed dependent on deposition pattern as well as dissolution rate. MATERIALS AND METHODS: A mechanistic model of airway deposition, mucociliary clearance, dissolution, absorption, and dissipation was applied to simulate systemic exposure of the novel selective glucocorticoid receptor modulator, AZD5423, when dosed to healthy volunteers using two different nebulizers and two different dry powder inhalers in combination with two different primary particle size distributions...
October 14, 2016: Journal of Aerosol Medicine and Pulmonary Drug Delivery
Stephanie A Grayson, Pamela S Griffiths, Miriam K Perez, Giovanni Piedimonte
OBJECTIVE: Respiratory syncytial virus (RSV) is the most common cause of respiratory illness in infants and young children, but this virus is also capable of re-infecting adults throughout life. Universal precautions to prevent its transmission consist of gown and glove use, but masks and goggles are not routinely required because it is believed that RSV is unlikely to be transmitted by the airborne route. Our hypothesis was that RSV is present in respirable-size particles aerosolized by patients seen in a pediatric acute care setting...
October 14, 2016: Pediatric Pulmonology
Pourya Shahpoury, Gerhard Lammel, Alexandre Albinet, Aysun Sofuoglu, Yetkin Dumanoglu, Sait C Sofuoglu, Zdenek Wagner, Vladimir Zdimal
A model for gas-particle partitioning of polycyclic aromatic hydrocarbons (PAHs) was evaluated using poly-parameter linear free energy relationships (ppLFERs) following a multiphase aerosol scenario. The model differentiates between various organic (i.e. liquid water soluble (WS)/organic soluble (OS) organic matter (OM) and solid/semi-solid organic polymers) and inorganic phases of the particulate matter (PM). Dimethyl sulfoxide and polyurethane were assigned as surrogates to simulate absorption into the abovementioned organic phases, respectively, whereas soot, ammonium sulfate, and ammonium chloride simulated adsorption processes onto PM...
October 13, 2016: Environmental Science & Technology
Ivan Kourtchev, Chiara Giorio, Antti Manninen, Eoin Wilson, Brendan Mahon, Juho Aalto, Maija Kajos, Dean Venables, Taina Ruuskanen, Janne Levula, Matti Loponen, Sarah Connors, Neil Harris, Defeng Zhao, Astrid Kiendler-Scharr, Thomas Mentel, Yinon Rudich, Mattias Hallquist, Jean-Francois Doussin, Willy Maenhaut, Jaana Bäck, Tuukka Petäjä, John Wenger, Markku Kulmala, Markus Kalberer
Secondary organic aerosol (SOA) accounts for a dominant fraction of the submicron atmospheric particle mass, but knowledge of the formation, composition and climate effects of SOA is incomplete and limits our understanding of overall aerosol effects in the atmosphere. Organic oligomers were discovered as dominant components in SOA over a decade ago in laboratory experiments and have since been proposed to play a dominant role in many aerosol processes. However, it remains unclear whether oligomers are relevant under ambient atmospheric conditions because they are often not clearly observed in field samples...
October 13, 2016: Scientific Reports
Thiago C Carvalho, John P McCook, Niven R Narain, Jason T McConville
Coenzyme Q10 (CoQ10) is a poorly-water soluble compound that is being investigated for the treatment of carcinomas. The aim of this study was to investigate the feasibility of preparing phospholipid-stabilized dispersions of the anticancer agent for continuous pulmonary delivery using a vibrating-mesh nebulizer. We determined the physicochemical properties (drug particle size distribution in dispersion, zeta potential, surface tension, and rheology) and compared the aerosolization profiles (nebulization performance, aerodynamic drug deposition and total emitted dose) of dispersions of CoQ10 prepared with different phospholipids...
October 11, 2016: International Journal of Pharmaceutics
Francesca Tombolini, Stefano Listrani, Antonella Campopiano, Carmela Plebani
Penetration measurements through commercially available filtering facepieces were performed with monodisperse DEHS aerosols ranging from 0.03 μm to 0.40 μm (either singly charged or neutralized), before and after 500 mg of paraffin oil loading. The distinct behavior of Coulomb and polarization capture efficiency is studied: as in the case of non loading also in the case of loading 500 mg of paraffin oil, the electrostatic capture mechanisms are mainly due to the Coulomb contribution up to aerosol particle diameter of about 0...
2016: Industrial Health
Adriana R Oller, Günter Oberdörster
Dosimetric models are essential tools to refine inhalation risk assessments based on local respiratory effects. Dosimetric adjustments to account for differences in aerosol particle size and respiratory tract deposition and/or clearance among rodents, workers, and the general public can be applied to experimentally- and epidemiologically-determined points of departure (PODs) to calculate size-selected (e.g., PM10, inhalable aerosol fraction, respirable aerosol fraction) equivalent concentrations (e.g., HEC or Human Equivalent Concentration; REC or Rodent Equivalent Concentration)...
September 2016: Journal of Aerosol Science
Jayesh Dhanani, John F Fraser, Hak-Kim Chan, Jordi Rello, Jeremy Cohen, Jason A Roberts
Drug dosing in critically ill patients is challenging due to the altered drug pharmacokinetics-pharmacodynamics associated with systemic therapies. For many drug therapies, there is potential to use the respiratory system as an alternative route for drug delivery. Aerosol drug delivery can provide many advantages over conventional therapy. Given that respiratory diseases are the commonest causes of critical illness, use of aerosol therapy to provide high local drug concentrations with minimal systemic side effects makes this route an attractive option...
October 7, 2016: Critical Care: the Official Journal of the Critical Care Forum
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