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aerosol particle

L S Usmanova, M A Ziganshin, I T Rakipov, N M Lyadov, A E Klimovitskii, T A Mukhametzyanov, A V Gerasimov
Inhalation administration is a promising alternative to the invasive drug delivery methods. The particle size required for ideal drug aerosol preparation is between 1 and 3  μ m. The application of microspherical particles of solid dispersions enhances bioavailability of poorly soluble drugs due to the solubilization. In the present work, the spray drying process of the production of microspherical particles of solid dispersions of polyvinylpyrrolidone K29-32 with model hydrophobic drug, phenacetin, was optimized using the results of DSC, PXRD, and viscometry...
2018: BioMed Research International
M R Kholghy, G A Kelesidis, S E Pratsinis
Nucleation is an important, yet poorly understood step in soot formation. Here, the importance of reactive PAH dimerization in reducing soot nucleation reversibility is investigated by simulating soot formation in a so-called "nucleation" flame (P. Desgroux et al., Combust. Flame, 2017, 184, 153-166). There, inception of soot particles is prolonged at minimal subsequent growth. With only reversible PAH dimerization, the simulated soot concentration is negligible. Accounting however for PAH chemical bond formation after physical dimerization, stabilizes dimers by covalent bonds and increases the soot concentration by four orders of magnitude, in good agreement with Laser Induced Incandescence measurements...
March 15, 2018: Physical Chemistry Chemical Physics: PCCP
Swapna Upadhyay, Lena Palmberg
Air pollution leads to inhalation of several pulmonary stimulants that includes particulate matter (PM), and gaseous substances contributing significantly to the development of chronic lung diseases. However, the pathophysiological mechanism of air pollutant mediated pulmonary toxicity remains unclear. This is primarily due to the lack of efficient test systems, mimicing human inhalation exposure scenarios to air pollutants. The majority of the pulmonary in vitro-studies have been conducted using cell lines in submerged cell culture conditions and thereby overlooking the pulmonary physiology...
March 9, 2018: Toxicological Sciences: An Official Journal of the Society of Toxicology
Sunhye Kim, Tae-Young Kim, Seung-Muk Yi, Jongbae Heo
The sources of different pollutants contributing to ambient fine particles (PM2.5 ) on Daebu Island, Korea, were estimated. Twenty four hour integrated filter samples were collected from May 21-November 1, 2016, and analyzed for organic carbon, elemental carbon, ions, and trace elements. Positive matrix factorization was conducted on the PM2.5 chemical speciation data from the samples to define the pathways and sources of PM2.5 at the sampling site. A total of 80 samples and 24 chemical species were used to run the model and a total of nine sources were identified: secondary sulfate (29...
March 10, 2018: Journal of Environmental Management
Ziyu Zhao, Zhengwei Huang, Xuejuan Zhang, Ying Huang, Yingtong Cui, Cheng Ma, Guanlin Wang, Tim Freeman, Xiang-Yun Lu, Xin Pan, Chuanbin Wu
BACKGROUND: The hygroscopicity of raffinose carrier for dry powder inhaler (DPI) was the main obstacle for its further application. Hygroscopicity-induced agglomeration would cause deterioration of aerosolization performance of raffinose, undermining the delivery efficiency. METHODS: Cyclodextrin-raffinose binary carriers (CRBCs) were produced by spray-drying so as to surmount the above issue. Physicochemical attributes and formation mechanism of CRBCs were explored in detail...
March 13, 2018: Expert Opinion on Drug Delivery
Kun Li, Junling Li, Weigang Wang, Jiangjun Li, Chao Peng, Dong Wang, Maofa Ge
The formation of secondary organic aerosol (SOA) contains partitioning processes of the oxidation products between gas and particle phase, which could change the particle-phase composition when particles grow. However, the effects of these processes on the optical properties of SOA remain poorly understood. In this study, we performed smog chamber experiments to investigate the effects of gas-particle partitioning (GPP) on the refractive index (RI) and chemical composition of the m-xylene SOA. Here, we show that the GPP processes, as organic mass increases, can increase the proportions of semi- and intermediate volatile organic compounds (SVOCs and IVOCs) in the particle phase and result in the decrease of SOA RI real part for 0...
March 12, 2018: Journal of Physical Chemistry. A
Megan Suzanne Claflin, Paul J Ziemann
Substantial amounts of gas- and particle-phase organic nitrates have been reported in field studies of atmospheric chemistry conducted around the world, and it has been proposed that a significant fraction of these may be formed from the nighttime reaction of monoterpenes with NO3 radicals. In the study presented here, β-pinene (a major global monoterpene emission) was reacted with NO3 radicals in an environmental chamber and the molecular and functional group composition of the resulting secondary organic aerosol (SOA) was determined using a variety of methods...
March 12, 2018: Journal of Physical Chemistry. A
Fengxia Li, Jürgen Schnelle-Kreis, Josef Cyrys, Kathrin Wolf, Erwin Karg, Jianwei Gu, Jürgen Orasche, Gülcin Abbaszade, Annette Peters, Ralf Zimmermann
OBJECTIVE: to study the sources contributing to quasi-ultrafine particle (UFP) organic carbon and the spatial temporal variability of the sources. METHOD: 24h quasi-UFP (particulate matter <0.36μm in this study) was sampled at a reference site continuously and at one of 5 other sites (T1, T2, T3, T4 and B1) in parallel in Augsburg, Germany from April 11th, 2014 to February 22nd, 2015, attempting to conduct 2-week campaigns at each site in 3 different seasons...
March 7, 2018: Science of the Total Environment
Huan Xie, Limin Feng, Qingjing Hu, Yujiao Zhu, Huiwang Gao, Yang Gao, Xiaohong Yao
In this study, we determined the concentrations of water-extracted dimethylaminium (DMA+ ) and trimethylaminium (TMA+ ) in size-segregated atmospheric particles collected during three inland campaigns and one sea-beach campaign in Qingdao and five marine campaigns in marginal seas of China and the northwest Pacific Ocean. The averages of DMA+ and TMA+ in PM0.056 -10 (the sum of concentrations from 0.056 to 10μm) during each campaign ranged from 0.045 to 1.1nmolm-3 and from 0.029 to 0.53nmolm-3 , respectively...
March 7, 2018: Science of the Total Environment
Basanth Babu Eedara, Bhamini Rangnekar, Colin Doyle, Alex Cavallaro, Shyamal C Das
Pharmacotherapy of tuberculosis is potentially more efficient when delivered by the inhaled route than by the current oral and/or parenteral routes due to the higher concentration of drug reaching the primary region of infection in the lungs. This study investigated the influence of the amino acid L-leucine alone and in combination with the phospholipid, 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), on the aerosolization behaviour of the anti-TB drugs, pyrazinamide and moxifloxacin HCl. Spray dried powders of pyrazinamide (P), moxifloxacin (M) alone and in combination with 10% L-leucine (PL and ML) and 10% DPPC (PLD and MLD) were produced...
March 7, 2018: International Journal of Pharmaceutics
Guillaume Falgayrac, Damian Siepka, Elżbieta A Stefaniak, Guillaume Penel, Sophie Sobanska
The influence of six common substrates on the Raman imaging of micron-sized inorganic aerosol particles was examined. Laboratory-generated single-component particles of calcite (CaCO3 ) and mixed particles of calcite (CaCO3 ), nitratine (NaNO3 ), hematite (Fe2 O3 ) and anglesite (PbSO4 ) were deposited by cascade impaction on Ag, In, Si, SiO2 , microscope slide and TEM-grid substrates. The spectral contribution of substrates to Raman images of the deposited particles was evaluated by Multivariate Curve Resolution...
July 19, 2018: Analytica Chimica Acta
Manoj Kumar, Tarek Trabelsi, Joseph S Francisco
Urea is ubiquitous in rainwaters and aqueous aerosols in different environments. However, its atmospheric fate and the exact mechanism on how it influences new particle formation remains completely unexplored. Herein, we have used quantum chemical calculations and Born Oppenheimer molecular dynamics simulations to explore the potential role of urea in the particle formation events. The results suggest that urea binds more strongly to common acidic precursors than ammonia or monoamines and is capable of binding at most two molecules of an acidic precursor or hydroperoxyl radical via hydrogen bonding interactions...
March 9, 2018: Journal of Physical Chemistry. A
Paul J Hadwin, Timothy A Sipkens, Kevin A Thomson, Fengshan Liu, Kyle J Daun
Time-resolved laser-induced incandescence (TiRe-LII) data can be used to infer spatially and temporally resolved volume fractions and primary particle size distributions of soot-laden aerosols, but these estimates are corrupted by measurement noise as well as uncertainties in the spectroscopic and heat transfer submodels used to interpret the data. Estimates of the temperature, concentration, and size distribution of soot primary particles within a sample aerosol are typically made by nonlinear regression of modeled spectral incandescence decay, or effective temperature decay, to experimental data...
March 1, 2018: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Si He, Xia Wang, Runqiu Xia, Weiqi Jin, Jian'an Liang
A novel method to simulate the polarimetric infrared imaging of a synthetic sea surface with atmospheric Mie scattering effects is presented. The infrared emission, multiple reflections, and infrared polarization of the sea surface and the Mie scattering of aerosols are all included for the first time. At first, a new approach to retrieving the radiative characteristics of a wind-roughened sea surface is introduced. A two-scale method of sea surface realization and the inverse ray tracing of light transfer calculation are combined and executed simultaneously, decreasing the consumption of time and memory dramatically...
March 1, 2018: Applied Optics
Saideh Ghadimi, Giti Forghani, Gholam Abbas Kazemi
The Angouran Mine, located in northwest Iran, is the largest Zn-Pb producer in the Middle East. This study was designed to investigate the distribution, geochemistry, and mineralogy of the aerosols in the mining area and to assess their likely health impacts on the local residents. For this purpose, 36 aerosol samples were collected from 2014 to 2015 at nine sites located in mine district and upwind and downwind directions. The concentration of potentially toxic elements in the aerosols was determined using AAS instrument...
March 7, 2018: Environmental Geochemistry and Health
Jonathan P Reid, Allan K Bertram, David O Topping, Alexander Laskin, Scot T Martin, Markus D Petters, Francis D Pope, Grazia Rovelli
The importance of organic aerosol particles in the environment has been long established, influencing cloud formation and lifetime, absorbing and scattering sunlight, affecting atmospheric composition and impacting on human health. Conventionally, ambient organic particles were considered to exist as liquids. Recent observations in field measurements and studies in the laboratory suggest that they may instead exist as highly viscous semi-solids or amorphous glassy solids under certain conditions, with important implications for atmospheric chemistry, climate and air quality...
March 6, 2018: Nature Communications
Hyo-Jung Lee, Hong-Goo Lee, Yong-Bin Kwon, Ju-Young Kim, Yun-Seok Rhee, Jinmann Chon, Eun-Soek Park, Dong-Wook Kim, Chun-Woong Park
In this study, we prepared carrier-based formulations for dry powder inhalers by mixing bosentan microparticles with carrier, prepared in three separate types of lactose. Spray-dried, milled and sieved lactose resulted in formulations with various shapes, surface morphology and particle size distributions. In the spray-dried lactose, the micronized bosentan particles were trapped and strongly interlocked in the rugged surface of spray-dried lactose, whereas in the milled and sieved lactose they exhibited lower binding affinity onto the smooth surface of carrier...
March 3, 2018: European Journal of Pharmaceutical Sciences
David O De Haan, Enrico Tapavicza, Matthieu Riva, Tianqu Cui, Jason Douglas Surratt, Adam C Smith, Mary-Caitlin Jordan, Shiva Nilakantan, Marisol Almodovar, Tiffany N Stewart, Alexia de Loera, Audrey C De Haan, Mathieu Cazaunau, Aline Gratien, Edouard Pangui, Jean-Francois Doussin
Aqueous methylglyoxal chemistry has often been implicated as an important source of oligomers in atmospheric aerosol. Here we report on chemical analysis of brown carbon aerosol particles collected from cloud cycling / photolysis chamber experiments, where gaseous methylglyoxal and methylamine interacted with glycine, ammonium or methylammonium sulfate seed particles. Eighteen N-containing oligomers were identified in the particulate phase by liquid chromatography / diode array detection / electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry...
March 6, 2018: Environmental Science & Technology
Salah Awel, Richard A Kirian, Max O Wiedorn, Kenneth R Beyerlein, Nils Roth, Daniel A Horke, Dominik Oberthür, Juraj Knoska, Valerio Mariani, Andrew Morgan, Luigi Adriano, Alexandra Tolstikova, P Lourdu Xavier, Oleksandr Yefanov, Andrew Aquila, Anton Barty, Shatabdi Roy-Chowdhury, Mark S Hunter, Daniel James, Joseph S Robinson, Uwe Weierstall, Andrei V Rode, Saša Bajt, Jochen Küpper, Henry N Chapman
High-resolution Bragg diffraction from aerosolized single granulovirus nanocrystals using an X-ray free-electron laser is demonstrated. The outer dimensions of the in-vacuum aerosol injector components are identical to conventional liquid-microjet nozzles used in serial diffraction experiments, which allows the injector to be utilized with standard mountings. As compared with liquid-jet injection, the X-ray scattering background is reduced by several orders of magnitude by the use of helium carrier gas rather than liquid...
February 1, 2018: Journal of Applied Crystallography
Kevin Bihan, Noël Zahr, Marie-Hélène Becquemin, Xiao Lu, Jean-François Bertholon, Corinne Vezinet, Charlotte Arbelot, Antoine Monsel, Jean-Jacques Rouby, Olivier Langeron, Qin Lu
Objectives: Nebulized colistimethate sodium (CMS) can be used to treat ventilator-associated pneumonia caused by MDR bacteria. The influence of the diluent volume of CMS on aerosol delivery has never been studied. The main objectives of the study were to compare aerosol particle characteristics and plasma and urine pharmacokinetics between two diluent volumes in patients treated with nebulized CMS. Methods: A crossover study was conducted in eight patients receiving nebulized CMS every 8 h...
February 28, 2018: Journal of Antimicrobial Chemotherapy
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