Development of a Physiologically Relevant Online Chemical Assay To Quantify Aerosol Oxidative Potential.

Large-scale epidemiological studies have shown a close correlation between adverse human health effects and exposure to ambient particulate matter (PM). The oxidative potential (OP) of ambient PM has been implicated in inducing toxic effects associated with PM exposure. In particular, reactive oxygen species (ROS), either bound to PM or generated by particulate components in vivo, substantially contribute to the OP and therefore toxicity of PM by lowering antioxidant concentrations in the lung, which can subsequently lead to oxidative stress, inflammation, and disease.

Does centrifugation matter? Centrifugal force and spinning time alter the plasma metabolome.

Background: Centrifugation is an indispensable procedure for plasma sample preparation, but applied conditions can vary between labs.

Aim: Determine whether routinely used plasma centrifugation protocols (1500× 10 min; 3000× 5 min) influence non-targeted metabolomic analyses.

Methods: Nuclear magnetic resonance spectroscopy (NMR) and High Resolution Mass Spectrometry (HRMS) data were evaluated with sparse partial least squares discriminant analyses and compared with cell count measurements.

Retrieving the translational diffusion coefficient of water from experiments on single levitated aerosol droplets.

The time-dependent growth and shrinkage of aqueous aerosol particles trapped in an electrodynamic balance exposed to changes in relative humidity (RH) depend on the translational diffusion coefficient of water (DH2O). Resonances in the Mie scattering patterns of the illuminated micrometre-sized droplets are used to follow the compositional evolution through stepwise changes in RH. Under conditions where the diffusion of water molecules becomes sufficiently slow, e.

Morphologies of mixed organic/inorganic/aqueous aerosol droplets.

Despite major progress in the understanding of properties of tropospheric aerosol particles, it remains challenging to understand their physical state and morphology. To obtain more detailed knowledge of the phases, phase transitions and morphologies of internally mixed organic/inorganic aerosol particles, we evaluated liquid-liquid phase separation (LLPS), deliquescence relative humidity (DRH) and efflorescence relative humidity (ERH) of 33 organic/ammonium sulfate (AS)/H2O systems from our own and literature data. The organic fraction consists of single compounds or mixtures with up to ten aliphatic and/or aromatic components with carboxylic acid, hydroxyl, carbonyl, ether, and ester functionalities, covering O : C ratios between 0.

Measurements of thermodynamic and optical properties of selected aqueous organic and organic-inorganic mixtures of atmospheric relevance.

Atmospheric aerosol particles can exhibit liquid solution concentrations supersaturated with respect to the dissolved organic and inorganic species and supercooled with respect to ice. In this study, thermodynamic and optical properties of sub- and supersaturated aqueous solutions of atmospheric interest are presented. The density, refractive index, water activity, ice melting temperatures, and homogeneous ice freezing temperatures of binary aqueous solutions containing L(+)-tartaric acid, tannic acid, and levoglucosan and ternary aqueous solutions containing levoglucosan and one of the salts NH(4)HSO(4), (NH(4))(2)SO(4), and NH(4)NO(3) have been measured in the supersaturated concentration range for the first time.

Comparing the mechanism of water condensation and evaporation in glassy aerosol.

Atmospheric models generally assume that aerosol particles are in equilibrium with the surrounding gas phase. However, recent observations that secondary organic aerosols can exist in a glassy state have highlighted the need to more fully understand the kinetic limitations that may control water partitioning in ambient particles. Here, we explore the influence of slow water diffusion in the condensed aerosol phase on the rates of both condensation and evaporation, demonstrating that significant inhibition in mass transfer occurs for ultraviscous aerosol, not just for glassy aerosol.

High salt intake down-regulates colonic mineralocorticoid receptors, epithelial sodium channels and 11β-hydroxysteroid dehydrogenase type 2.

Besides the kidneys, the gastrointestinal tract is the principal organ responsible for sodium homeostasis. For sodium transport across the cell membranes the epithelial sodium channel (ENaC) is of pivotal relevance. The ENaC is mainly regulated by mineralocorticoid receptor mediated actions.

Experimental evidence for excess entropy discontinuities in glass-forming solutions.

Glass transition temperatures T(g) are investigated in aqueous binary and multi-component solutions consisting of citric acid, calcium nitrate (Ca(NO(3))(2)), malonic acid, raffinose, and ammonium bisulfate (NH(4)HSO(4)) using a differential scanning calorimeter. Based on measured glass transition temperatures of binary aqueous mixtures and fitted binary coefficients, the T(g) of multi-component systems can be predicted using mixing rules. However, the experimentally observed T(g) in multi-component solutions show considerable deviations from two theoretical approaches considered.

Epigenetic regulation of somatic angiotensin-converting enzyme by DNA methylation and histone acetylation.

Somatic angiotensin-converting enzyme (sACE) is crucial in cardiovascular homeostasis and displays a tissue-specific profile. Epigenetic patterns modulate genes expression and their alterations were implied in pathologies including hypertension. However, the influence of DNA methylation and chromatin condensation state on the expression of sACE is unknown.