Organic acids in aerosols Earth's atmosphere are ubiquitous and they have been extensively studied across urban, rural and polar environments. However, little is known about their properties, transport, source and seasonal variations in the Svalbard Archipelago. Here, we present the annual trend of organic acids in the aerosol collected at Ny-Ålesund and consider their size-distributions to infer their possible sources and relative contributions. A series of carboxylic acids were detected with a predominance of C2-oxalic acid. Pinic acid and cis-pinonic acid were studied in order to better understand the oxidative and gas-to-particle processes occurred in the Arctic atmosphere. Since the water-soluble organic fraction is mainly composed by organic acids and ions, we investigated how the seasonal variation leads to different atmospheric transport mechanisms, focusing on the chemical variations between the polar night and boreal summer. Using major ions, levoglucosan and MSA, the Positive Matrix Factorization (PMF) identified five different possible sources: a) sea spray; b) marine primary production; c) biomass burning; d) sea ice related process and e) secondary products.
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http://dx.doi.org/10.1016/j.scitotenv.2020.142954 | DOI Listing |
Sci Rep
December 2024
Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Falmouth, USA.
Coral reef sponges efficiently take up particulate and dissolved organic matter (DOM) from the water column and release compounds such as nucleosides, amino acids, and other dissolved metabolites to the surrounding reef via their exhalent seawater, but the influence of this process on reef picoplankton and nutrient processing is relatively unexplored. Here we examined the impact of sponge exhalent on the reef picoplankon community and subsequent alterations to the reef dissolved metabolite pool. We exposed reef picoplankton communities to a sponge exhalent water mixture (Niphates digitalis and Xestospongia muta) or filtered reef seawater (control) in closed, container-based dark incubations.
View Article and Find Full Text PDFCommun Med (Lond)
December 2024
Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, Rostock University Medical Center, Rostock, Germany.
Background: Menopause driven decline in estrogen exposes women to risk of osteoporosis. Detection of early onset and silent progression are keys to prevent fractures and associated burdens.
Methods: In a discovery cohort of 120 postmenopausal women, we combined repeated quantitative pulse-echo ultrasonography of bone, assessment of grip strength and serum bone markers with mass-spectrometric analysis of exhaled metabolites to find breath volatile markers and quantitative cutoff levels for osteoporosis.
Bioresour Technol
December 2024
Bioprocesses Department, Instituto Politécnico Nacional, P.O. Box 07340, Mexico City, Mexico. Electronic address:
A biohydrogen and polyhydroxyalkanoates(PHA)-producing natural photoheterotrophic mixed culture composed mainly by Rhodopseudomonas palustris and Clostridium sp was studied by a proteomic analysis under non-growth conditions (nitrogen-absence and organic acids). Proteins in C. pasteurianum were upregulated, particularly those related to stress response.
View Article and Find Full Text PDFPlant Sci
December 2024
Instituto de Fisiología Vegetal (INFIVE CCT CONICET La Plata), Universidad Nacional de La Plata (UNLP) y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Diagonal 113 Nº 495 (1900) La Plata, Argentina. Electronic address:
Nitrate reductase (NR) is an essential enzyme because of its role in nitrogen metabolism and in key signaling events through the generation of the reactive nitrogen species, nitric oxide (NO). In this work, we evaluated changes in endogenous NO levels during the onset of P-restriction in soybean plants (Glycine max), focusing on the possible pathways involved in its generation, namely NR and NO synthase like activity, NOS, and the subsequent role of NR during low P-acclimation. During the first 96h of P-starvation NO levels increased in the leaves.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China. Electronic address:
Naturally aged microplastics (NAMPs) are commonly found in farmland soils contaminated with heavy metals (HMs), such as arsenic (As) and cadmium (Cd); yet their combined effects on soil-plant ecosystems remain poorly understood. In this study, we investigated the toxic effects of NAMPs and As-Cd on lettuce, considering the influence of earthworm activity, and examined changes in As-Cd bioavailability in the rhizosphere. Four experimental systems were established: soil-only, soil-lettuce, soil-earthworms, and soil-lettuce-earthworms systems, with four NAMPs concentrations (0, 0.
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