@article {99,
	title = {Coal fly ash impairs airway antimicrobial peptides and increases bacterial growth.},
	journal = {PLoS One},
	volume = {8},
	year = {2013},
	note = {CAPLUS AN 2013:396251(Journal; Online Computer File)},
	pages = {e57673},
	publisher = {Public Library of Science},
	abstract = {Air pollution is a risk factor for respiratory infections, and one of its main components is particulate matter (PM), which is comprised of a no. of particles that contain iron, such as coal fly ash (CFA).  Since free iron concns. are extremely low in airway surface liq. (ASL), we hypothesize that CFA impairs antimicrobial peptides (AMP) function and can be a source of iron to bacteria.  We tested this hypothesis in vivo by instilling mice with Pseudomonas aeruginosa (PA01) and CFA and det. the percentage of bacterial clearance.  In addn., we tested bacterial clearance in cell culture by exposing primary human airway epithelial cells to PA01 and CFA and detg. the AMP activity and bacterial growth in vitro.  We report that CFA is a bioavailable source of iron for bacteria.  We show that CFA interferes with bacterial clearance in vivo and in primary human airway epithelial cultures.  Also, we demonstrate that CFA inhibits AMP activity in vitro, which we propose as a mechanism of our cell culture and in vivo results.  Furthermore, PA01 uses CFA as an iron source with a direct correlation between CFA iron dissoln. and bacterial growth.  CFA concns. used are very relevant to human daily exposures, thus posing a potential public health risk for susceptible subjects.  Although CFA provides a source of bioavailable iron for bacteria, not all CFA particles have the same biol. effects, and their propensity for iron dissoln. is an important factor.  CFA impairs lung innate immune mechanisms of bacterial clearance, specifically AMP activity.  We expect that identifying the PM mechanisms of respiratory infections will translate into public health policies aimed at controlling, not only concn. of PM exposure, but physicochem. characteristics that will potentially cause respiratory infections in susceptible individuals and populations. [on SciFinder(R)]},
	isbn = {1932-6203},
	author = {Borcherding, Jennifer A. and Chen, Haihan and Caraballo, Juan C. and Baltrusaitis, Jonas and Pezzulo, Alejandro A. and Zabner, Joseph and Grassian, Vicki H. and Comellas, Alejandro P.}
}
@article {129,
	title = {Coal fly ash as iron source in atmospheric dust.},
	journal = {Environmental Science \& Technology},
	volume = {46},
	year = {2012},
	note = {CAPLUS AN 2012:79841(Journal; Online Computer File)},
	month = {2012///},
	pages = {2112 - 2120},
	publisher = {American Chemical Society},
	abstract = {Anthropogenic coal fly ash (FA) aerosol may represent a significant source of bioavailable iron in the open ocean.  Few measurements have been made that compare the soly. of atm. iron from anthropogenic aerosols and other sources.  We report here an investigation of iron dissoln. for three FA samples in acidic aq. solns. and compare the solubilities with that of Arizona test dust (AZTD), a ref. material for mineral dust.  The effects of pH, simulated cloud processing, and solar radiation on iron soly. have been explored.  Similar to previously reported results on mineral dust, iron in aluminosilicate phases provides the predominant component of dissolved iron.  Iron soly. of FA is substantially higher than of the cryst. minerals comprising AZTD.  Simulated atm. processing elevates iron soly. due to significant changes in the morphol. of aluminosilicate glass, a dominant material in FA particles.  Iron is continuously released into the aq. soln. as FA particles break up into smaller fragments.  These results suggest that the assessment of dissolved atm. iron deposition fluxes and their effect on the biogeochem. at the ocean surface should be constrained by the source, environmental pH, iron speciation, and solar radiation. [on SciFinder(R)]},
	keywords = {coal fly ash iron atm dust qual analysis aluminosilicate},
	isbn = {0013-936X},
	author = {Chen, Haihan and Laskin, Alexander and Baltrusaitis, Jonas and Gorski, Christopher A. and Scherer, Michelle M. and Grassian, Vicki H.}
}
@article {149,
	title = {Carbon dioxide adsorption on oxide nanoparticle surfaces.},
	journal = {Chemical Engineering Journal (Amsterdam, Netherlands)},
	volume = {170},
	year = {2011},
	note = {CAPLUS AN 2011:672234(Journal; Online Computer File)},
	month = {2011///},
	pages = {471 - 481},
	publisher = {Elsevier B.V.},
	abstract = {In this paper, focused on environmental nanotechnol., we review some recent results for carbon dioxide (CO2) adsorption on hydroxylated Fe2O3, γ-Al2O3, and TiO2 nanoparticle surfaces at 296 K as followed by transmission FTIR spectroscopy.  In the absence of water vapor (<1\% relative humidity, RH), following exposure to CO2 different species formed on the oxide surface due to the presence of adsorption sites with different basicities.  While the majority surface species on Fe2O3, γ-Al2O3 is detd. to be adsorbed bicarbonate, on TiO2 nanoparticles bidentate carbonate was more prevalent.  A carboxylate species was obsd. on TiO2 nanoparticles under dry conditions as well.  When water is present at 40\% RH, the nature of the adsorbed CO2 species changed to that of solvated carbonate formation in the adsorbed water layer.  Obsd. initial adsorption rates were calcd. from time-course expts. under dry conditions and in the presence of 40\% RH.  When initial adsorption rates were compared between dry and wet expts., a larger value was found for dry expts. suggesting that CO2 mols. have to compete for adsorption sites with water on these nanoparticle surfaces.  As discussed here, quantum chem. calcns. provide some addnl. insights into CO2 adsorption on hydroxylated metal oxide surfaces in the presence and absence of molecularly adsorbed water. [on SciFinder(R)]},
	keywords = {carbon dioxide adsorption oxide nanoparticle surface relative humidity water},
	isbn = {1385-8947},
	author = {Baltrusaitis, Jonas and Schuttlefield, Jennifer and Zeitler, Elizabeth and Grassian, Vicki H.}
}
@article {164,
	title = {Carbonic Acid Formation from Reaction of Carbon Dioxide and Water Coordinated to Al(OH)3: A Quantum Chemical Study.},
	journal = {Journal of Physical Chemistry A},
	volume = {114},
	year = {2010},
	note = {CAPLUS AN 2010:112419(Journal)},
	month = {2010///},
	pages = {2350 - 2356},
	publisher = {American Chemical Society},
	abstract = {D. functional and ab initio calcns. have been performed on CO2-nH2O and Al(OH)3-CO2-nH2O (where n = 1, 2, 3) cluster models to elucidate the catalytic effect of a hydroxylated metal center on the formation of carbonic acid (H2CO3).  B3LYP/6-311++G(d,p)-calcd. geometries and RI-SCS-MP2/aug-cc-pVTZ//B3LYP/6-311++G(d,p)-calcd. energies with respect to isolated gas-phase mols. and various H2O, CO2, and H2CO3-Al(OH)3 complexes are presented.  It is shown here that H2CO3 formation proceeds via direct CO2 and nH2O reaction with very high activation barriers in the gas phase, 51.40, 29.64, and 19.84 kcal/mol for CO2-H2O, CO2-2H2O, and CO2-3H2O clusters, resp., decreasing in magnitude with an increase in the no. of H2O mols.  The energetics as well as the reaction mechanism and energy landscape change significantly when carbonic acid is formed from CO2 and nH2O in the presence of Al(OH)3, a hydroxylated metal center.  Results presented here show important details of the influence of the coordinating metal center in the formation of H2CO3. [on SciFinder(R)]},
	keywords = {carbonic acid formation quantum chem, reaction carbon dioxide water coordinated aluminum hydroxide quantum chem},
	isbn = {1089-5639},
	author = {Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {173,
	title = {Calcite ( 1 0 1 4 ) surface in humid environments.},
	journal = {Surface Science},
	volume = {603},
	year = {2009},
	note = {CAPLUS AN 2009:1033091(Journal)},
	month = {2009///},
	pages = {L99-L104},
	publisher = {Elsevier B.V.},
	abstract = {A.c. mode At. Force Microscopy (AFM) height images combined with force measurements and phase imaging were used to investigate the surface reconstruction and chem. of the lowest energy surface, ( 1 0 1 4 ) plane, of calcite, a stable form of calcium carbonate (CaCO3), in the presence of relative humidity at different temps.  At 296 K and 70\% RH, calcite ( 1 0 1 4 ) undergoes rapid restructuring during hydration forming regions on the surface that are most likely characterized as an amorphous hydrate layer similar to what forms in soln. under high [Ca2+] supersatn. conditions.  This hydrate layer in turn serves as a substrate for the crystn. of another layer that possesses structural properties which differ from hydrate layer.  Phase imaging reveals that these different layer structures formed in the process of water adsorption and surface reconstruction have very different energy dissipation modes.  The origin of the different dissipation modes are likely due to differences in water content and hydrophobicity of these regions.  The newly formed layer on top of the hydration layer is proposed to be vaterite, another polymorph of CaCO3.  At 278 K the formation mechanism of the vaterite layer changes due to nucleation of a more cryst. hydrate layer, similar to CaCO3 hexahydrate, instead of the amorphous hydrate layer that forms at 296 K.  Force measurements corroborate the assignment of the speciation of different regions on the surface.  Importantly, the AFM data show that the surface of calcite is highly inhomogeneous with regions that vary in water content.  The reactivity of calcite in humid environments will be highly spatially dependent. [on SciFinder(R)]},
	keywords = {calcite surface humidity hydration vaterite nucleation},
	isbn = {0039-6028},
	author = {Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {180,
	title = {Characterization and acid-mobilization study of iron-containing mineral dust source materials.},
	journal = {Journal of Geophysical Research, [Atmospheres]},
	volume = {113},
	year = {2008},
	note = {CAPLUS AN 2008:617952(Journal)},
	month = {2008///},
	pages = {D05202/1-D05202/18},
	publisher = {American Geophysical Union},
	abstract = {Processes that solubilize iron in mineral dust aerosol may increase the amt. of iron supplied to ocean surface waters, and thereby stimulate phytoplankton productivity.  In particular, the uptake of acids such as H2SO4 and HNO3 on mineral dust surfaces can produce extremely acidic environments that promote iron dissoln.  Here, four samples that represent source materials for mineral dust (Saudi Beach sand (SB), Inland Saudi sand (IS), Saharan Sand (SS) and China Loess (CL)) and one com. ref. material (Arizona Test Dust (AZTD)) were characterized, and examd. in dissoln. studies in solns. of sulfuric, nitric and hydrochloric acid ranging from pH 1 to 3.  Mossbauer spectroscopy revealed Fe(III) in all samples, whereas SB, CL and AZTD also contained appreciable Fe(II).  Spectra suggest that both Fe(II) and Fe(III) were substituted into aluminosilicates, although CL, AZTD and IS also contained Fe(III) oxide phases.  Total iron soly. measured after 24 h ranged between 4-16\% of the initial iron content for each material, but did not scale with either the sp. surface area or the total iron content of the samples.  Instead, we show that Fe(II)-contg. solid phases such as Fe(II)-substituted aluminosilicates represent a significant, and sometimes dominant, source of sol. Fe in acidic environments.  Results of dissoln. studies also show that the nature of the acid influences iron solubilization, as elevated concns. of nitrate encountered from nitric acid at pH 1 suppressed Fe(II) formation.  We propose a surface-mediated, non-photochem. redox reaction between nitrate and Fe(II), which may contribute to Fe(II)/Fe(III) cycling in the atm. [on SciFinder(R)]},
	keywords = {iron mineral dust source material acid mobilization},
	author = {Cwiertny, David M. and Baltrusaitis, Jonas and Hunter, Gordon J. and Laskin, Alexander and Scherer, Michelle M. and Grassian, Vicki H.}
}
@conference {183,
	title = {Chemical properties of oxide nanoparticles: surface adsorption studies from gas- and liquid-phase environments.},
	booktitle = {Synthesis, Properties, Applications of Oxide Nanomaterials},
	year = {2007},
	note = {CAPLUS AN 2007:1408672(Conference; General Review)},
	month = {2007///},
	pages = {335 - 351},
	publisher = {John Wiley \& Sons, Inc.},
	organization = {John Wiley \& Sons, Inc.},
	abstract = {A review.  This article is to describe the potential use of ATR-FTIR spectroscopy, which is somewhat unique in that surface adsorption can be investigated at both the nanoparticle oxide/gas and nanoparticle oxide/liq. interfaces.  The mol. nature of oxide nanoparticle surfaces will most likely be different in these two phases.  The quantification of surface adsorption as a function of size could be done with this technique under these different conditions.  The results should be revealing and may provide addnl. insight into the chem. properties of oxide nanoparticles. [on SciFinder(R)]},
	keywords = {review oxide nanoparticle surface adsorption ATR FTIR spectroscopy interface},
	author = {Pettibone, John M. and Baltrusaitis, Jonas and Grassian, Vicki H.}
}
