147 research outputs found
Characterizing the Chemical Profile of Incidental Ultrafine Particles for Toxicity Assessment Using an Aerosol Concentrator
Incidental ultrafine particles (UFPs) constitute a key pollutant in industrial workplaces. However,
characterizing their chemical properties for exposure and toxicity assessments still remains a challenge. In this work, the performance of an aerosol concentrator (Versatile Aerosol Concentration
Enrichment System, VACES) was assessed to simultaneously sample UFPs on filter substrates (for
chemical analysis) and as liquid suspensions (for toxicity assessment), in a high UFP concentration
scenario. An industrial case study was selected where metal-containing UFPs were emitted during
thermal spraying of ceramic coatings. Results evidenced the comparability of the VACES system with
online monitors in terms of UFP particle mass (for concentrations up to 95 µg UFP/m3
) and between
filters and liquid suspensions, in terms of particle composition (for concentrations up to 1000 µg/
m3). This supports the applicability of this tool for UFP collection in view of chemical and toxicological characterization for incidental UFPs. In the industrial setting evaluated, results showed that
the spraying temperature was a driver of fractionation of metals between UF (<0.2 µm) and fine (0.2–
2.5 µm) particles. Potentially health hazardous metals (Ni, Cr) were enriched in UFPs and depleted in
the fine particle fraction. Metals vaporized at high temperatures and concentrated in the UF fraction
through nucleation processes. Results evidenced the need to understand incidental particle formation mechanisms due to their direct implications on particle composition and, thus, exposure. It is
advisable that personal exposure and subsequent risk assessments in occupational settings should
include dedicated metrics to monitor UFPs (especially, incidental).What’s important about this paper: Our work addresses the challenge of characterizing the bulk chemical composition of ultrafine particles in occupational settings, for exposure and toxicity assessments. We tested the performance of an aerosol concentrator (VACES) to simultaneously sample ultrafine particles (UFPs) on filter substrates and as liquid suspensions, in a high UFP concentration scenario. An industrial case study was selected where metal-bearing UFPs were emitted. We report the chemical exposures characterized in the industrial facility, and evidence the comparability of the VACES system with online monitors for UFP particle mass (up to 95 µg UFP/m3) as well as between UFP chemical composition on filters and in suspension. This supports the applicability of this tool for UFP collection in view of chemical and toxicological characterization of exposures to incidental UFPs in workplace settings.Highlights: - The VACES system is a useful tool for UFP sampling in high-concentration settings; - UFP collected simultaneously on filters and in suspension showed good comparability; - UFP chemical profiles were characterized; - Health-hazardous metals Ni and Cr accumulated in UFPs; - Understanding emission mechanisms is key to identifying exposure sources.This work was funded by SIINN ERA-NET (project id: 16), the
Spanish MINECO (PCIN-2015-173-C02-01) and the French
agency (Region Hauts de France). The Spanish Ministry of
Science and Innovation (Project CEX2018-000794-S; Severo
Ochoa) and the Generalitat de Catalunya (project number:
AGAUR 2017 SGR41) provided support for the indirect costs
for the Institute of Environmental Assessment and Water
Research (IDAEA-CSIC). We acknowledge support of the publication fee by the CSIC Open Access Publication Support
Initiative through its Unit of Information Resources for
Research (URICI).info:eu-repo/semantics/publishedVersio
The metabolic microenvironment of melanomas: prognostic value of MCT1 and MCT4
BRAF mutations are known drivers of melanoma development and, recently, were also described as players in the Warburg effect, while this reprogramming of energy metabolism has been identified as a possible strategy for treating melanoma patients. Therefore, the aim of this work was to evaluate the expression and prognostic value of a panel of glycolytic metabolism-related proteins in a series of melanomas. The immunohistochemical expression of MCT1, MCT4, GLUT1, and CAIX was evaluated in 356 patients presenting melanoma and 20 patients presenting benign nevi. Samples included 20 benign nevi, 282 primary melanomas, 117 lymph node and 54 distant metastases samples. BRAF mutation was observed in 29/92 (31.5%) melanoma patients and 17/20 (85%) benign nevi samples. NRAS mutation was observed in 4/36 (11.1%) melanoma patients and 1/19 (5.3%) benign nevi samples. MCT4 and GLUT1 expression was significantly increased in metastatic samples, and MCT1, MCT4 and GLUT1 were significantly associated with poor prognostic variables. Importantly, MCT1 and MCT4 were associated with shorter overall survival. In conclusion, the present study brings new insights on metabolic aspects of melanoma, paving the way for the development of new-targeted therapies.This work was supported by FAPESP grant to VLV (2012/04194-1) and CP (2015/25351-6). VMG received a doctoral fellowship (SFRH/BD/51997/2012) from Fundacao para a Ciencia e a Tecnologia (FCT) and ON. 2 SR&TD Integrated Program (NORTE-07-0124-FEDER-000017) co-funded by Programa Operacional Regional do Norte (ON.2- O Novo Norte), Quadro de Referencia Estrategico Nacional (QREN), through Fundo Europeu de Desenvolvimento Regional (FEDER).info:eu-repo/semantics/publishedVersio
The Growth of Intracluster Light in XCS-HSC Galaxy Clusters from
We estimate the Intracluster Light (ICL) component within a sample of 18 clusters detected in XMM Cluster Survey (XCS) data using deep ( 26.8 mag) Hyper Suprime Cam Subaru Strategic Program DR1 (HSC-SSP DR1) -band data. We apply a rest-frame isophotal threshold to our clusters, below which we define light as the ICL within an aperture of (X-ray estimate of ) centered on the Brightest Cluster Galaxy (BCG). After applying careful masking and corrections for flux losses from background subtraction, we recover 20% of the ICL flux, approximately four times our estimate of the typical background at the same isophotal level ( 5%). We find that the ICL makes up about 24% of the total cluster stellar mass on average ( 41% including the flux contained in the BCG within 50 kpc); this value is well-matched with other observational studies and semi-analytic/numerical simulations, but is significantly smaller than results from recent hydrodynamical simulations (even when measured in an observationally consistent way). We find no evidence for any links between the amount of ICL flux with cluster mass, but find a growth rate of for the ICL between . We conclude that the ICL is the dominant evolutionary component of stellar mass in clusters from . Our work highlights the need for a consistent approach when measuring ICL alongside the need for deeper imaging, in order to unambiguously measure the ICL across as broad a redshift range as possible (e.g. 10-year stacked imaging from the Vera C. Rubin Observatory)
Parent of origin genetic effects on methylation in humans are common and influence complex trait variation
Parent-of-origin effects (POE) are observed when there are different effects from alleles inherited from the two parents on phenotypic measures. Here, Zeng et al. study POE on DNA methylation in 5,101 individuals and identify genetic variants that associate with methylation variation via POE and their potential phenotypic consequences
Drug resistance, AmpC-β-lactamase and extended-spectrum β-lactamase-producing Enterobacteriaceae isolated from fish and shrimp
ABSTRACT The present study aims to detect the production of extended-spectrum beta-lactamases (ESBL) by enterobacteria isolated from samples of fresh shrimp and fish obtained from the retail trade of the city of Sobral, Ceará State, Brazil. All bacterial isolates were submitted to identification and antimicrobial susceptibility testing using aminopenicillin, beta-lactamase inhibitors, carbapenem, 1st, 2nd, 3rd and 4th generation cephalosporins, and monobactam. Three types of beta-lactamases - ESBL, AmpC and KPC - were investigated. 103 strains were identified, and the most frequent species in shrimp and fish samples was Enterobacter cloacae (n = 54). All the strains were resistant to penicillin and more than 50% of the isolates were resistant to ampicillin and cephalothin. Resistance to three 3rd generation cephalosporins (cefotaxime, ceftriaxone and ceftazidime) and one fourth generation cephalosporin (cefepime) was detected in two isolates of E. cloacae from shrimp samples. Phenotypic detection of AmpC was confirmed in seven strains. The ESBL was detected in two strains of E. cloacae from shrimp samples. No strain showed KPC production. These data can be considered alarming, since food (shrimp and fish) may be carriers of enterobacteria resistant to drugs of clinical interest
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