4,174 results match your criteria variability emission


Reducing Planetary Health Risks Through Short-Lived Climate Forcer Mitigation.

Geohealth 2021 Jul 1;5(7):e2021GH000422. Epub 2021 Jul 1.

Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment Technology School of Environmental Science and Engineering Nanjing University of Information Science Technology Nanjing China.

Global air pollution and climate change are major threats to planetary health. These threats are strongly linked through the short-lived climate forcers (SLCFs); ozone (O), aerosols, and methane (CH). Understanding the impacts of ambitious SLCF mitigation in different source emission sectors on planetary health indicators can help prioritize international air pollution control strategies. Read More

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[Determination of Bone SPECT Image Reconstruction Conditions in the Head and Neck Region].

Nihon Hoshasen Gijutsu Gakkai Zasshi 2021 ;77(7):700-709

Division of Radiology, Department of Medical Technology, Kochi Medical School Hospital.

Purpose: Quantitative analysis using a standardized uptake value (SUV) has become possible for single-photon emission computed tomography-computed tomography (SPECT-CT) of bone. However, previous research was targeted to the trunk area, and there are few studies for the head and neck region. Therefore, the purpose of this study was to determine the optimal image reconstruction conditions for bone SPECT of the head and neck using a phantom study. Read More

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Production of a broad palette of positron emitting radioisotopes using a low-energy cyclotron: Towards a new success story in cancer imaging?

Appl Radiat Isot 2021 Jul 12;176:109860. Epub 2021 Jul 12.

Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India.

Over the last several years, positron emission tomography (PET) has matured as an indispensable component of cancer diagnostics. Owing to the large variability observed among the cancer patients and the need to personalize individual patient's diagnosis and treatment, the need for new positron emitting radioisotopes has continued to grow. This mini review opens with a brief introduction to the criteria for radioisotope selection for PET imaging. Read More

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Aerosol-based antimicrobial photoinactivation in the lungs: an action spectrum study.

Photochem Photobiol Sci 2021 Jul 17. Epub 2021 Jul 17.

Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, viale Pieraccini 6, 50139, Florence, Italy.

Chronic lung infections are among the most diffused human infections, being often associated with multidrug-resistant bacteria. In this framework, the European project "Light4Lungs" aims at synthesizing and testing an inhalable light source to control lung infections by antimicrobial photoinactivation (aPDI), addressing endogenous photosensitizers only (porphyrins) in the representative case of S. aureus and P. Read More

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Assessment of potential process quality indicators for systemic treatment of breast cancer in Belgium: a population-based study.

ESMO Open 2021 Jul 14;6(4):100207. Epub 2021 Jul 14.

Department of Medical Oncology, AZ Klina, Brasschaat, Belgium; University of Antwerp, Antwerp, Belgium.

Background: Quality indicators (QIs) for the management of breast cancer (BC) have been published in Europe and internationally. In Belgium, a task force was established to select measurable process indicators of systemic treatment for BC, focusing on appropriateness of delivered care. The objective of this study was to evaluate the results of the selected QIs, both nationally and among individual centres. Read More

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Characterizing Fuel Use and Emission Hotspots for a Diesel-Operated Passenger Rail Service.

Environ Sci Technol 2021 Jul 16. Epub 2021 Jul 16.

Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, North Carolina 27695-7908, United States.

Spatially varying diesel locomotive fuel use and emission rates (FUERs) are needed to accurately quantify local emission hotspots and their health impacts. However, existing locomotive FUER data are typically not spatially resolved or representative of real-world locomotive operation. Therefore, existing data are of limited use in quantifying the spatial variability in real-world FUERs. Read More

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Simulating Pollutant Dispersion from Accidental Fires with a Focus on Source Characterization.

J Health Pollut 2021 Jun 17;11(30):210612. Epub 2021 Jun 17.

Politecnico di Milano, Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Milan, Italy.

Background: Storage tanks in oil and gas processing facilities contain large volumes of flammable compounds. Once the fuel-air mixture is ignited, it may break out into a large fire or explosion. The growing interest in monitoring air quality and assessing health risks makes the evaluation of the consequences of a fire an important issue. Read More

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Variability and Time of Day Dependence of Ozone Photochemistry in Western Wildfire Plumes.

Environ Sci Technol 2021 Jul 13. Epub 2021 Jul 13.

NOAA Chemical Sciences Laboratory, Boulder, Colorado 80305, United States.

Understanding the efficiency and variability of photochemical ozone (O) production from western wildfire plumes is important to accurately estimate their influence on North American air quality. A set of photochemical measurements were made from the NOAA Twin Otter research aircraft as a part of the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) experiment. We use a zero-dimensional (0-D) box model to investigate the chemistry driving O production in modeled plumes. Read More

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Förster Resonance Energy Transfer Measurements in Living Plant Cells.

J Vis Exp 2021 Jun 28(172). Epub 2021 Jun 28.

Dynamic Cell Imaging, Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University;

Sensitized emission-based Förster resonance energy transfer (FRET) experiments are easily done but depend on the microscopic setup. Confocal laser scanning microscopes have become a workhorse for biologists. Commercial systems offer high flexibility in laser power adjustment and detector sensitivity and often combine different detectors to obtain the perfect image. Read More

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Validation of the influence of CT slice thickness on the quantitative accuracy and image quality of single photon emission computed tomography.

Asia Ocean J Nucl Med Biol 2021 ;9(2):148-157

Department of Radiology, Chiba Aoba Municipal Hospital, Chiba City, Japan.

Objectives: Computed tomography (CT) images are used for precise anatomical location of lesions and for accurate attenuation correction in single-photon emission computed tomography (SPECT) image reconstruction in SPECT/CT examination. The aim of this study was to verify the effects of varying CT collimation width and slice thickness on CT images and on CT attenuation corrected SPECT images.

Methods: We acquired SPECT/CT images of a micro-coin phantom and the National Electrical Manufacturers Association body phantom filled with Tc-pertechnetate while varying the abovementioned CT parameters. Read More

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January 2021

Exploratory Analysis of F-3'-deoxy-3'-fluorothymidine (F-FLT) PET/CT-Based Radiomics for the Early Evaluation of Response to Neoadjuvant Chemotherapy in Patients With Locally Advanced Breast Cancer.

Front Oncol 2021 24;11:601053. Epub 2021 Jun 24.

Nuclear Medicine Unit, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) "Dino Amadori," Meldola, Italy.

Purpose: The objective of this study was to evaluate a set of radiomics-based advanced textural features extracted from F-FLT-PET/CT images to predict tumor response to neoadjuvant chemotherapy (NCT) in patients with locally advanced breast cancer (BC).

Materials And Methods: Patients with operable (T2-T3, N0-N2, M0) or locally advanced (T4, N0-N2, M0) BC were enrolled. All patients underwent chemotherapy (six cycles every 3 weeks). Read More

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A new approach for health-oriented ozone control strategy: Adjoint-based optimization of NO emission reductions using metaheuristic algorithms.

J Clean Prod 2021 Aug;312(20):127533

Department of Geography and Resource Management, The Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong, China.

While levels of particulate matters in the Pearl River Delta Region (PRD) show a significant reduction, ozone (O) has an opposite increasing trend, becoming the critical air quality target in this decade. Emission control strategies are typically formulated sector by sector, spatial variability in emissions reductions and health impacts of air pollutants may not be taken into account, affecting the overall effectiveness of control strategies. This study proposes an adjoint-based optimization framework to facilitate health-oriented O control over PRD. Read More

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A modified fluorescent sensor for reporting glucose concentration in the airway lumen.

PLoS One 2021 9;16(7):e0254248. Epub 2021 Jul 9.

Institute for Infection and Immunity, St George's University of London, London, United Kingdom.

We have modified the periplasmic Escherichia coli glucose/galactose binding protein (GBP) and labelled with environmentally sensitive fluorophores to further explore its potential as a sensor for the evaluation of glucose concentration in airway surface liquid (ASL). We identified E149C/A213R GBP labelled with N,N'-Dimethyl-N-(iodoacetyl)-N'-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)ethylenediamine (IANBD, emission wavelength maximum 536nm) with a Kd for D-glucose of 1.02mM and a fluorescence dynamic range of 5. Read More

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Distinct Profiles of 50 kHz Vocalizations Differentiate Between Social Versus Non-social Reward Approach and Consumption.

Front Behav Neurosci 2021 21;15:693698. Epub 2021 Jun 21.

Comparative Psychology, Institute of Experimental Psychology, Heinrich-Heine-University, Düsseldorf, Germany.

Social animals tend to possess an elaborate vocal communication repertoire, and rats are no exception. Rats utilize ultrasonic vocalizations (USVs) to communicate information about a wide range of socially relevant cues, as well as information regarding the valence of the behavior and/or surrounding environment. Both quantitative and qualitative acoustic properties of these USVs are thought to communicate context-specific information to conspecifics. Read More

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Diurnal variability in soil nitrous oxide emissions is a widespread phenomenon.

Glob Chang Biol 2021 Jul 7. Epub 2021 Jul 7.

UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Bailrigg, Lancaster, UK.

Manual measurements of nitrous oxide (N O) emissions with static chambers are commonly practised. However, they generally do not consider the diurnal variability of N O flux, and little is known about the patterns and drivers of such variability. We systematically reviewed and analysed 286 diurnal data sets of N O fluxes from published literature to (i) assess the prevalence and timing (day or night peaking) of diurnal N O flux patterns in agricultural and forest soils, (ii) examine the relationship between N O flux and soil temperature with different diurnal patterns, (iii) identify whether non-diurnal factors (i. Read More

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Using a hybrid approach to apportion potential source locations contributing to excess cancer risk of PM-bound PAHs during heating and non-heating periods in a megacity in the Middle East.

Environ Res 2021 Jul 3;201:111617. Epub 2021 Jul 3.

Dipartimento di Scienze Ambientali Informatica e Statistica, Università Ca' Foscari Venezia, Venezia, Italy.

Polycyclic aromatic hydrocarbons (PAHs) represent one of the major toxic pollutants associated with PM with significant human health and climate effects. Because of local and long-range transport of atmospheric PAHs to receptor sites, higher global attentions have been focused to improve PAHs pollution emission management. In this study, PM samples were collected at three urban sites located in the capital of Iran, Tehran, during the heating and non-heating periods (H-period and NH-period). Read More

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Tracking POPs in Global Air from the First 10 Years of the GAPS Network (2005 to 2014).

Environ Sci Technol 2021 Jul 2;55(14):9479-9488. Epub 2021 Jul 2.

Department of Civil and Environmental Engineering and IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City, Iowa 52242, United States of America.

The Global Atmospheric Passive Sampling (GAPS) network, initiated in 2005 across 55 global sites, supports the global monitoring plan (GMP) of the Stockholm Convention on Persistent Organic Pollutants (POPs) by providing information on POP concentrations in air on a global scale. These data inform assessments of the long-range transport potential of POPs and the effectiveness evaluation of chemical regulation efforts, by observing changes in concentrations over time. Currently, measurements spanning 5-10 sampling years are available for 40 sites from the GAPS Network. Read More

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Source Apportionment of Aerosol at a Coastal Site and Relationships with Precipitation Chemistry: A Case Study over the Southeast United States.

Atmosphere (Basel) 2020 Nov 10;11(11):1212. Epub 2020 Nov 10.

Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, AZ 85721, USA.

This study focuses on the long-term aerosol and precipitation chemistry measurements from colocated monitoring sites in Southern Florida between 2013 and 2018. A positive matrix factorization (PMF) model identified six potential emission sources impacting the study area. The PMF model solution yielded the following source concentration profiles: (i) combustion; (ii) fresh sea salt; (iii) aged sea salt; (iv) secondary sulfate; (v) shipping emissions; and (vi) dust. Read More

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November 2020

A transfer learning approach to facilitate ComBat-based harmonization of multicentre radiomic features in new datasets.

PLoS One 2021 1;16(7):e0253653. Epub 2021 Jul 1.

INSERM, UMR 1101, LaTIM, University of Brest, Brest, France.

Purpose: To facilitate the demonstration of the prognostic value of radiomics, multicenter radiomics studies are needed. Pooling radiomic features of such data in a statistical analysis is however challenging, as they are sensitive to the variability in scanner models, acquisition protocols and reconstruction settings, which is often unavoidable in a multicentre retrospective analysis. A statistical harmonization strategy called ComBat was utilized in radiomics studies to deal with the "center-effect". Read More

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Fractal motor activity regulation and sex differences in preclinical Alzheimer's disease pathology.

Alzheimers Dement (Amst) 2021 23;13(1):e12211. Epub 2021 Jun 23.

Medical Biodynamics Program Brigham and Women's Hospital Boston Massachusetts USA.

Introduction: Degradation in fractal motor activity regulation (FMAR), a measure of multiscale self-similarity of motor control, occurs in aging and accelerates with clinical progression to Alzheimer's disease (AD). Whether FMAR changes occur during the pre-symptomatic phase of the disease in women and men remains unknown.

Methods: FMAR was assessed in cognitively normal participants (n = 178) who underwent 7 to 14 days of home actigraphy. Read More

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Characterization of Chinese hamster ovary cell culture feed media precipitate.

Biotechnol Prog 2021 Jun 24:e3188. Epub 2021 Jun 24.

Department of Chemical Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA.

Process intensification of monoclonal antibody production is leading to more concentrated feed media causing issues with precipitation of solids from the media solution. This results in processing problems since components in the precipitate are no longer in solution, changing the media composition and leading to variability in cell culture performance. The goal of this work is to characterize the feed media precipitate, and in particular to identify the precipitated components so that mitigation strategies can be developed. Read More

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CO -responsiveness of leaf isoprene emission: Why do species differ?

Plant Cell Environ 2021 Jun 21. Epub 2021 Jun 21.

Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia.

Leaf isoprene emission rate, I, decreases with increasing atmospheric CO concentration with major implications for global change. There is a significant interspecific variability in [CO ]-responsiveness of I, but the extent of this variation is unknown and its reasons are not understood. We hypothesized that the magnitude of emission reduction reflects the size and changeability of precursor pools responsible for isoprene emission (dimethylallyl diphosphate, DMADP and 2-methyl-erythritol 2,4-cyclodiphosphate, MEcDP). Read More

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Exploring personal chemical exposures in China with wearable air pollutant monitors: A repeated-measure study in healthy older adults in Jinan, China.

Environ Int 2021 Jun 19;156:106709. Epub 2021 Jun 19.

Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT 06520, USA. Electronic address:

The health impact of airborne contaminants has been challenging to assess due to current limitations in measurement technologies. The emergence of wearable passive samplers coupled with high resolution mass spectrometry (HR-MS) chemical analysis has enabled comprehensive characterization of personal exposures. We conducted a repeated-measure study among 84 older adults in Jinan, China, as part of the Biomarkers for Air Pollutants Exposure (China BAPE) study. Read More

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Reverberation mapping of active galactic nuclei: from X-ray corona to dusty torus.

iScience 2021 Jun 19;24(6):102557. Epub 2021 May 19.

MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139, USA.

The central engines of active galactic nuclei (AGNs) are powered by accreting supermassive black holes, and while AGNs are known to play an important role in galaxy evolution, the key physical processes occur on scales that are too small to be resolved spatially (aside from a few exceptional cases). Reverberation mapping is a powerful technique that overcomes this limitation by using echoes of light to determine the geometry and kinematics of the central regions. Variable ionizing radiation from close to the black hole drives correlated variability in surrounding gas/dust but with a time delay due to the light travel time between the regions, allowing reverberation mapping to effectively replace spatial resolution with time resolution. Read More

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Large model structural uncertainty in global projections of urban heat waves.

Nat Commun 2021 06 18;12(1):3736. Epub 2021 Jun 18.

Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO, USA.

Urban heat waves (UHWs) are strongly associated with socioeconomic impacts. Here, we use an urban climate emulator combined with large ensemble global climate simulations to show that, at the urban scale a large proportion of the variability results from the model structural uncertainty in projecting UHWs in the coming decades under climate change. Omission of this uncertainty would considerably underestimate the risk of UHW. Read More

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A novel theory of Asian elephant high-frequency squeak production.

BMC Biol 2021 Jun 17;19(1):121. Epub 2021 Jun 17.

Department of Behavioural and Cognitive Biology, Mammal Communication Lab, University of Vienna, Vienna, Austria.

Background: Anatomical and cognitive adaptations to overcome morpho-mechanical limitations of laryngeal sound production, where body size and the related vocal apparatus dimensions determine the fundamental frequency, increase vocal diversity across taxa. Elephants flexibly use laryngeal and trunk-based vocalizations to form a repertoire ranging from infrasonic rumbles to higher-pitched trumpets. Moreover, they are among the few evolutionarily distantly related animals (humans, pinnipeds, cetaceans, birds) capable of imitating species-atypical sounds. Read More

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Respirators, face masks, and their risk reductions via multiple transmission routes for first responders within an ambulance.

J Occup Environ Hyg 2021 07 15;18(7):345-360. Epub 2021 Jun 15.

Department of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, Arizona.

First responders may have high SARS-CoV-2 infection risks due to working with potentially infected patients in enclosed spaces. The study objective was to estimate infection risks per transport for first responders and quantify how first responder use of N95 respirators and patient use of cloth masks can reduce these risks. A model was developed for two Scenarios: an ambulance transport with a patient actively emitting a virus in small aerosols that could lead to airborne transmission (Scenario 1) and a subsequent transport with the same respirator or mask use conditions, an uninfected patient; and remaining airborne SARS-CoV-2 and contaminated surfaces due to aerosol deposition from the previous transport (Scenario 2). Read More

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On the Long-Term Temporal Variations in Methane Emissions from an Unconventional Natural Gas Well Site.

ACS Omega 2021 Jun 27;6(22):14200-14207. Epub 2021 May 27.

Mechanical & Aerospace Engineering, West Virginia University, P.O. Box 6106, Morgantown, West Virginia26506, United States.

Understanding methane emissions from the natural gas supply chain continues to be of interest. Previous studies identified that measurements are skewed due to "super-emitters", and recently, researchers identified temporal variability as another contributor to discrepancies among studies. We focused on the latter by performing 17 methane audits at a single production site over 4 years, from 2016 to 2020. Read More

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Experimental phantom evaluation to identify robust positron emission tomography (PET) radiomic features.

EJNMMI Phys 2021 Jun 12;8(1):46. Epub 2021 Jun 12.

German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany.

Background: Radiomics analysis usually involves, especially in multicenter and large hospital studies, different imaging protocols for acquisition, reconstruction, and processing of data. Differences in protocols can lead to differences in the quantification of the biomarker distribution, leading to radiomic feature variability. The aim of our study was to identify those radiomic features robust to the different degrading factors in positron emission tomography (PET) studies. Read More

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Comparative in vitro study of commercially available products for alveolar ridge preservation.

J Periodontol 2021 Jun 11. Epub 2021 Jun 11.

Naval Medical Research Unit San Antonio, JBSA, Fort Sam Houston, TX.

Background: Ridge preservation is performed by placing a biocompatible product, following tooth extraction, to maintain bone volume. However, current ridge preservation therapies do not always maintain the volume required for future implant placement. Variations in surgical technique and material selection contribute to determining clinical outcomes. Read More

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