Residential indoor and outdoor fine particle (PM(2.5)) organic (OC) and elemental carbon (EC) concentrations (48 h) were measured at 173 homes in Houston, TX, Los Angeles County, CA, and Elizabeth, NJ as part of the Relationship of Indoor, Outdoor and Personal Air (RIOPA) study. The adsorption of organic vapors on the quartz fiber sampling filter (a positive artifact) was substantial indoors and out, accounting for 36% and 37% of measured OC at the median indoor (8.2 microg C/m(3)) and outdoor (5.0 microg C/m(3)) OC concentrations, respectively. Uncorrected, adsorption artifacts would lead to substantial overestimation of particulate OC both indoors and outdoors. After artifact correction, the mean particulate organic matter (OM=1.4 OC) concentration indoors (9.8 microg/m(3)) was twice the mean outdoor concentration (4.9 microg/m(3)). The mean EC concentration was 1.1 microg/m(3) both indoors and outdoors. OM accounted for 29%, 30% and 29% of PM(2.5) mass outdoors and 48%, 55% and 61% of indoor PM(2.5) mass in Los Angeles Co., Elizabeth and Houston study homes, respectively. Indirect evidence provided by species mass balance results suggests that PM(2.5) nitrate (not measured) was largely lost during outdoor-to-indoor transport, as reported by Lunden et al. This results in dramatic changes with outdoor-to-indoor transport in the mass and composition of ambient-generated PM(2.5) at California homes. On average, 71% to 76% of indoor OM was emitted or formed indoors, calculated by (1) Random Component Superposition (RCS) model and (2) non-linear fit of OC and air exchange rate data to the mass balance model. Assuming that all particles penetrate indoors (P=1) and there is no particle loss indoors (k=0), a lower bound estimate of 41% of indoor OM was indoor-generated (mean). OM appears to be the predominant species in indoor-generated PM(2.5), based on species mass balance results. Particulate OM emitted or formed indoors is substantial enough to alter the concentration, composition and behavior of indoor PM(2.5). One interesting effect of increased indoor OM concentrations is a shift in the gas-particle partitioning of polycyclic aromatic hydrocarbons (PAHs) from the gas to the particle phase with outdoor-to-indoor transport.
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http://dx.doi.org/10.1038/sj.jes.7500476 | DOI Listing |
Methods Mol Biol
January 2025
Biomic Auth, Bioanalysis and Omics Laboratory, Centre for Interdisciplinary Research of Aristotle, University of Thessaloniki, Innovation Area of Thessaloniki, Thermi, Greece.
The gut's symbiome, a hidden metabolic organ, has gained scientific interest for its crucial role in human health. Acting as a biochemical factory, the gut microbiome produces numerous small molecules that significantly impact host metabolism. Metabolic profiling facilitates the exploration of its influence on human health and disease through the symbiotic relationship.
View Article and Find Full Text PDFJ Food Sci
January 2025
Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning, China.
Fermentation is crucial for inducing desirable flavor and aroma profiles in cocoa products. This research focused on identifying microbial strains isolated from spontaneous cocoa fermentation in Hainan through 16S and Internal Transcribed Spacer (ITS) sequencing. Pectinase activity was screened, and metabolic dynamics of sugars and organic acids were analyzed using high-performance liquid chromatography.
View Article and Find Full Text PDFPhotosynthetica
January 2025
Plant Physiology Sector, State University of Norte Fluminense, Center for Sciences and Agricultural Technologies (CCTA), Avenida Alberto Lamego, 2000, 28015-620, Campos dos Goytacazes, RJ, Brazil.
The aim was to investigate the morphological, photosynthetic, and hydraulic physiological characteristics of different genotypes of under controlled cultivation conditions. Growth, conductance, and hydraulic conductivity of the root system of 16 genotypes were evaluated in Experiment 1 (November 2013). In Experiment 2 (December 2014), in addition to the previous characteristics, gas exchange, photochemical efficiency, leaf water potential, and leaf hydraulic conductivity were investigated in five genotypes.
View Article and Find Full Text PDFWearable Technol
November 2024
Department of Kinesiology, Iowa State University, Ames, IA, USA.
Placing an inertial measurement unit (IMU) at the 5th lumbar vertebra (L5) is a frequently employed method to assess the whole-body center of mass (CoM) motion during walking. However, such a fixed position approach does not account for instantaneous changes in body segment positions that change the CoM. Therefore, this study aimed to assess the congruence between CoM accelerations obtained from these two methods.
View Article and Find Full Text PDFOrthop J Sports Med
January 2025
Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
Background: The growing popularity of glucagon-like peptide-1 receptor agonists (GLP-1-RAs) for weight loss could significantly impact joint preservation and arthroplasty. While this will in part be driven by the association between obesity, osteoarthritis (OA), and total joint arthroplasty (TJA), recent evidence also indicates that GLP-1-RAs may have direct joint-protective, anti-inflammatory effects.
Purpose: To evaluate the association between GLP-1-RA use and the onset and progression of hip and knee OA in an obese population.
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