Gas chromatography with mass spectrometric detection (GC-MS) coupled with solid phase micro-extraction as pre-concentration method (SPME) was applied to identify and quantify volatile organic compounds (VOCs) emitted by human skin. A total of 64 C4-C10 compounds were quantified in skin emanation of 31 healthy volunteers. Amongst them aldehydes and hydrocarbons were the predominant chemical families with eighteen and seventeen species, respectively. Apart from these, there were eight ketones, six heterocyclic compounds, six terpenes, four esters, two alcohols, two volatile sulphur compounds, and one nitrile. The observed median emission rates ranged from 0.55 to 4,790 fmol cm(-2)min(-1). Within this set of analytes three volatiles; acetone, 6-methyl-5-hepten-2-one, and acetaldehyde exhibited especially high emission rates exceeding 100 fmol cm(-2)min(-1). Thirty-three volatiles were highly present in skin emanation with incidence rates over 80%. These species can be considered as potential markers of human presence, which could be used for early location of entrapped victims during Urban Search and Rescue Operations (USaR).
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http://dx.doi.org/10.1016/j.jchromb.2014.04.006 | DOI Listing |
Environ Sci Pollut Res Int
January 2025
Program in Biodiversity and Nature Conservation (UFJF), Institute of Biological Sciences (ICB), Federal University of Juiz de Fora (UFJF), University Campus, Martelos, Juiz de Fora, Minas Gerais, CEP, 36036-900, Brazil.
In 2020, the largest continuous wetland area on the planet, the Brazilian Pantanal, experienced an unprecedented fire that affected the entire ecosystem. Our goal was to elucidate the effects of ash presence following the fire events. We quantified the impact of ashes, collected in four Conservation Units, on soil, water, and atmosphere.
View Article and Find Full Text PDFJAMA Neurol
January 2025
Department of Radiology, Mayo Clinic, Rochester, Minnesota.
Importance: Although 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established cross-sectional biomarker of brain metabolism in dementia with Lewy bodies (DLB), the longitudinal change in FDG-PET has not been characterized.
Objective: To investigate longitudinal FDG-PET in prodromal DLB and DLB, including a subsample with autopsy data, and report estimated sample sizes for a hypothetical clinical trial in DLB.
Design, Setting, And Participants: Longitudinal case-control study with mean (SD) follow-up of 3.
Cureus
December 2024
Pathological Anatomy, Instituto Português de Oncologia do Porto Francisco Gentil, Porto, PRT.
Sclerosing epithelioid fibrosarcoma (SEF) is a rare and aggressive neoplasm composed of epithelioid cells arranged in strands and nests embedded in a highly sclerotic collagenous stroma. We report a case of a 36-year-old man who started with lumbar pain, with extension to both legs, night sweats, and weight loss. He underwent magnetic resonance imaging (MRI) of the lumbar spine; computed tomography (CT) scan of the chest, abdomen, and pelvis; and [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China.
Molecular photoswitch research has drawn much attention in the last century owing to its great potential in the development of smart materials. However, photoswitches suitable for constructing light-responsive luminescent materials remain limited, especially those involving triplet-state phosphorescence. Herein, we designed a novel molecular photoswitch based on the conformation transition of phenothiazine derivatives, minimizing steric hindrance (-CH > -Cl > -F) to regulate the conformation transition process while introducing a cyanobenzene acceptor to promote phosphorescence emission potential.
View Article and Find Full Text PDFJ Alzheimers Dis
January 2025
Genentech, Inc., South San Francisco, CA, USA.
Background: In Alzheimer's disease (AD), tau and white matter lesion pathology are associated with clinical severity and subsequent decline, but their relative relationships with clinical assessments remain uncertain.
Objective: To examine cross-sectional and prognostic associations between baseline [F]GTP1 tau positron emission tomography (PET) standardized uptake value ratio (SUVRs) and T1 white matter hypointensity (WMHypo) volumes with clinical indices.
Methods: We analyzed participants with biomarker-confirmed prodromal (n = 127) or mild (n = 233) AD with baseline [F]GTP1 tau PET and MRI and longitudinal Clinical Dementia Rating-Sum of Boxes (CDR-SB), 13-item version of the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog13), Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Mini-Mental Status Examination (MMSE), and Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) data.
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