Chemical Differences in Environmental Films Collected on Surfaces with Different Hydrophilicity.

Environmental films form when airborne particles and molecular species adsorb on solid surfaces. Recent studies have characterized these films but overlook how collection methods and host-surface character (orientation, chemical functionality, or height) change the deposition process. In this work, environmental films are collected at a rural location on gold and silicon surfaces (water contact angles of ca.

Enhanced light absorption for solid-state brown carbon from wildfires due to organic and water coatings.

Wildfires emit solid-state strongly absorptive brown carbon (solid S-BrC, commonly known as tar ball), critical to Earth's radiation budget and climate, but their highly variable light absorption properties are typically not accounted for in climate models. Here, we show that from a Pacific Northwest wildfire, over 90% of particles are solid S-BrC with a mean refractive index of 1.49 + 0.

Harvest Initiated Volatile Organic Compound Emissions from In-Field Tall Wheatgrass.

While crop and grassland usage continues to increase, the full diversity of plant-specific volatile organic compounds (VOCs) emitted from these ecosystems, including their implications for atmospheric chemistry and carbon cycling, remains poorly understood. It is particularly important to investigate VOCs in the context of potential biofuels: aside from the implications of large-scale land use, harvest may shift both the flux and speciation of emitted VOCs. To this point, we evaluate the diversity of VOCs emitted both pre and postharvest from "Alkar" tall wheatgrass (), a candidate biofuel that exhibits greater tolerance to frost and saline land compared to other grass varieties.

Tethered balloon system and High-Resolution Mass Spectrometry Reveal Increased Organonitrates Aloft Compared to the Ground Level.

Atmospheric particles play critical roles in climate. However, significant knowledge gaps remain regarding the vertically resolved organic molecular-level composition of atmospheric particles due to aloft sampling challenges. To address this, we use a tethered balloon system at the Southern Great Plains Observatory and high-resolution mass spectrometry to, respectively, collect and characterize organic molecular formulas (MF) in the ground level and aloft (up to 750 m) samples.

Quantifying the Chemical Composition and Real-Time Mass Loading of Nanoplastic Particles in the Atmosphere Using Aerosol Mass Spectrometry.

Plastic debris, including nanoplastic particles (NPPs), has emerged as an important global environmental issue due to its detrimental effects on human health, ecosystems, and climate. Atmospheric processes play an important role in the transportation and fate of plastic particles in the environment. In this study, a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was employed to establish the first online approach for identification and quantification of airborne submicrometer polystyrene (PS) NPPs from laboratory-generated and ambient aerosols.

A plasma membrane-associated form of the androgen receptor enhances nuclear androgen signaling in osteoblasts and prostate cancer cells.

Androgen binding to the androgen receptor (AR) in the cytoplasm induces the AR to translocate to the nucleus, where it regulates the expression of target genes. Here, we found that androgens rapidly activated a plasma membrane-associated signaling node that enhanced nuclear AR functions. In murine primary osteoblasts, dihydrotestosterone (DHT) binding to a membrane-associated form of AR stimulated plasma membrane-associated protein kinase G type 2 (PKG2), leading to the activation of multiple kinases, including ERK.

Exploiting the microbiome associated with normal and abnormal sprouting rice (Oryza sativa L.) seed phenotypes through a metabarcoding approach.

Rice germination and seedlings' growth are crucial stages that influence crop establishment and productivity. These performances depend on several factors, including the abundance and diversity of seed microbial endophytes. Two popular rainfed rice varieties cultivated in Cameroon, NERICA 3 and NERICA 8, were used for investigating the seed-associated microbiome using the Illumina-based 16 S rRNA gene.

Alkylperoxy radicals are responsible for the formation of oxygenated primary organic aerosol.

Organic aerosol (OA) is an air pollutant ubiquitous in urban atmospheres. Urban OA is usually apportioned into primary OA (POA), mostly emitted by mobile sources, and secondary OA (SOA), which forms in the atmosphere due to oxidation of gas-phase precursors from anthropogenic and biogenic sources. By performing coordinated measurements in the particle phase and the gas phase, we show that the alkylperoxy radical chemistry that is responsible for low-temperature ignition also leads to the formation of oxygenated POA (OxyPOA).

Optical Properties of Individual Tar Balls in the Free Troposphere.

Tar balls are brown carbonaceous particles that are highly viscous, spherical, amorphous, and light absorbing. They are believed to form in biomass burning smoke plumes during transport in the troposphere. Tar balls are also believed to have a significant impact on the Earth's radiative balance, but due to poorly characterized optical properties, this impact is highly uncertain.

Nonequilibrium Behavior in Isoprene Secondary Organic Aerosol.

Recent studies have shown that instantaneous gas-particle equilibrium partitioning assumptions fail to predict SOA formation, even at high relative humidity (∼85%), and photochemical aging seems to be one driving factor. In this study, we probe the minimum aging time scale required to observe nonequilibrium partitioning of semivolatile organic compounds (SVOCs) between the gas and aerosol phase at ∼50% RH. Seed isoprene SOA is generated by photo-oxidation in the presence of effloresced ammonium sulfate seeds at <1 ppbv NO, aged photochemically or in the dark for 0.

Cloud condensation nuclei activity of internally mixed particle populations at a remote marine free troposphere site in the North Atlantic Ocean.

This study reports results from research conducted at the Observatory of Mount Pico (OMP), 2225 m above mean sea level on Pico Island in the Azores archipelago in June and July 2017. We investigated the chemical composition, mixing state, and cloud condensation nuclei (CCN) activities of long-range transported free tropospheric (FT) particles. FLEXible PARTicle Lagrangian particle dispersion model (FLEXPART) simulations reveal that most air masses that arrived at the OMP during the sampling period originated in North America and were highly aged (average plume age > 10 days).

Electric-Field-Induced Assembly of an Ionic Liquid-Water Interphase Enables Efficient Heavy Metal Electrosorption.

Controlling ion desolvation, transport, and charge transfer at the electrode-electrolyte interface (EEI) is critical to enable the rational design of the efficient and selective separation of targeted heavy metals and the decontamination of industrial wastewater. The main challenge is to sufficiently resolve and interrogate the desolvation of solvated metal ions and their subsequent electroreduction at the EEI and establish pathways to modulate these intermediate steps to achieve efficient energy transfer for targeted reactive separations. Herein, we obtained a predictive understanding of modulating the desolvation and electrosorption of Pb cations using the hydrophobic ionic liquid 1-ethyl-3-methylimidazolium chloride (EMIMCl) in aqueous electrolyte.

A Microbial Co-Culturing System for Producing Cellulose-Hyaluronic Acid Composites.

In this study, a co-culture system combining bacterial cellulose (BC) producers and hyaluronic acid (HA) producers was developed for four different combinations. AAB of the genus sp. and LAB of the genus were used to produce BC and HA, respectively.

Acetic acid bacteria in agro-wastes: from cheese whey and olive mill wastewater to cellulose.

In this study, cheese whey and olive mill wastewater were investigated as potential feedstocks for producing bacterial cellulose by using acetic acid bacteria strains. Organic acids and phenolic compounds composition were assayed by high-pressure liquid chromatography. Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction were used to investigate modifications in bacterial cellulose chemical and morphological structure.

Vertical Gradient of Size-Resolved Aerosol Compositions over the Arctic Reveals Cloud Processed Aerosol in-Cloud and above Cloud.

Arctic aerosols play a significant role in aerosol-radiation and aerosol-cloud interactions, but ground-based measurements are insufficient to explain the interaction of aerosols and clouds in a vertically stratified Arctic atmosphere. This study shows the vertical variability of a size resolved aerosol composition via a tethered balloon system at Oliktok Point, Alaska, at different cloud layers for two representative case studies (background aerosol and polluted conditions). Multimodal microspectroscopy analysis during the background case reveals a broadening of chemically specific size distribution above the cloud top with a high abundance of sulfate particles and core-shell morphology, suggesting possible cloud processing of aerosols.

Defining (P8) and (UMCC 2951) strains performances in producing acetic acid.

In this study, spore-forming bacteria isolated from saccharified rice were selected for producing acetic acid. From the screening of 15 strains, P8 strain was chosen as a candidate. The strain was identified as by 16S rRNA analysis (99.

Better under stress: Improving bacterial cellulose production by K2G30 (UMCC 2756) using adaptive laboratory evolution.

Among naturally produced polymers, bacterial cellulose is receiving enormous attention due to remarkable properties, making it suitable for a wide range of industrial applications. However, the low yield, the instability of microbial strains and the limited knowledge of the mechanisms regulating the metabolism of producer strains, limit the large-scale production of bacterial cellulose. In this study, K2G30 was adapted in mannitol based medium, a carbon source that is also available in agri-food wastes.

Cobinamide is a strong and versatile antioxidant that overcomes oxidative stress in cells, flies, and diabetic mice.

Increased oxidative stress underlies a variety of diseases, including diabetes. Here, we show that the cobalamin/vitamin B analog cobinamide is a strong and multifaceted antioxidant, neutralizing superoxide, hydrogen peroxide, and peroxynitrite, with apparent rate constants of 1.9 × 10, 3.

Candidate Acetic Acid Bacteria Strains for Levan Production.

In this study, twelve strains of acetic acid bacteria (AAB) belonging to five different genera were tested for their ability to produce levan, at 70 and 250 g/L of sucrose concentration, respectively. The fructan produced by the bacterial strains was characterized as levan by NMR spectroscopy. Most of the strains produced levan, highlighting intra- and inter-species variability.

Direct observation and assessment of phase states of ambient and lab-generated sub-micron particles upon humidification.

We present a new analytical platform that uses a tilted stage (60°) integrated to the Peltier cooling stage interfaced with an Environmental Scanning Electron Microscope (ESEM) to directly observe and assess the phase state of particles as a function of RH at a controlled temperature. Three types of organic particles have been studied: (a) Suwannee River Fulvic Acid (SRFA) particles, (b) lab generated soil organic particles, and (c) field-collected ambient particles. The chemical composition, morphology, and functional groups of individual particles were probed using computer-controlled scanning electron microscopy with energy-dispersive X-ray spectroscopy (CCSEM/EDX) and scanning transmission X-ray microscopy with near-edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS).

Solid organic-coated ammonium sulfate particles at high relative humidity in the summertime Arctic atmosphere.

SignificancePhysical and chemical properties of individual atmospheric particles determine their climate impacts. Hygroscopic inorganic salt particles mixed with trace amounts of organic material are predicted to be liquid under typical tropospheric conditions in the summertime Arctic. Yet, we unexpectedly observed a significant concentration of solid particles composed of ammonium sulfate with an organic coating under conditions of high relative humidity and low temperature.