510 results match your criteria: "UMR 5254 CNRS-Université de Pau[Affiliation]"

Comparison of Untargeted and Markers Analysis of Volatile Organic Compounds with SIFT-MS and SPME-GC-MS to Assess Tea Traceability.

Foods

December 2024

IPREM, Institut des Sciences Analytiques et de Physicochimie Pour L'environnement et les Matériaux, UMR 5254, Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IMT Mines Ales, Helioparc, 2 Avenue President Angot, 64053 Pau, CEDEX 9, France.

Tea is one of the most consumed beverages in the world and presents a great aromatic diversity depending on the origin of the production and the transformation process. Volatile organic compounds (VOCs) greatly contribute to the sensory perception of tea and are excellent markers for traceability and quality. In this work, we analyzed the volatile organic compounds (VOCs) emitted by twenty-six perfectly traced samples of tea with two analytical techniques and two data treatment strategies.

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This study investigates whether nanoplastics are significant contributor of rare earth elements (Gd) transportation under environmental conditions. Important effects of nanoplastic concentration, Gd concentration, complexation with organic ligands, pH, ionic strength and occurrence of natural colloids competitor were studied thanks to an experimental design combining incubation follow by ultrafiltration and ICPMS analyses. In particular, we observed that even in sea water, about half of the gadolinium can be adsorbed on nanoplastics.

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Herein, we report the structure-based selection via molecular docking of four -heterocyclic bis-carbene gold(I) complexes, whose potential as ligands for the hTel23 G-quadruplex structure has been investigated using circular dichroism (CD) spectroscopy, CD melting, and polyacrylamide gel electrophoresis (PAGE). The complex containing a bis(1,2,3,4,6,7,8,9-octahydro-11-11-pyridazino[1,2-a]indazol-11-yl) scaffold induces a transition from the hybrid (3 + 1) topology to a prevalent parallel G-quadruplex conformation, whereas the complex featuring a bis(2-(2-acetamidoethyl)-3-imidazo[1,5-a]pyridin-3(2)-yl) moiety disrupted the original G-quadruplex structure. These results deserve particular attention in light of the recent findings on the pathological involvements of G-quadruplexes in neurodegenerative diseases.

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Polyelectrolyte brush in a cylindrical pore: A Poisson-Boltzmann theory.

J Chem Phys

November 2024

CNRS, Université de Pau et des Pays de l'Adour UMR 5254, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, Pau, France.

The conformation of a polyelectrolyte (PE) brush grafted to the inner surface of a long cylindrical mesopore was described within analytical Poisson-Boltzmann strong stretching approximation. The internal structure of the PE brush, including brush thickness and radial density profile of monomer units, and radial distribution of electrostatic potential were analyzed as functions of the pore radius, degree of polymerization, and grafting density of the brush-forming PE chains as well as ionic strength of the solution. It is demonstrated that narrowing of the pore leads to a non-monotonous variation of the brush thickness, which passes through a maximum when the brush thickness becomes equal to the pore radius.

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The European eel (Anguilla anguilla) juvenile stage exhibits facultative estuarine migration. The causes of this behavior are yet unknown but it may have an impact on the population's fate by altering the sex ratio of the population. Recent studies have highlighted potential stress-related issues in glass eels settling in estuaries but studying stress response in small organisms requires sensitive, accurate and precise analytical methods.

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Perfluorooctanoic acid (PFOA) is a persistent organic pollutant that accumulates in the human body, leading to major health issues. Upon oral uptake, the gastrointestinal tract is the first biological barrier against PFOA. However, the localization of PFOA and its impact on the intestinal wall are largely unknown.

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Hypervalent iodine-mediated cyclization of bishomoallylamides to prolinols.

Beilstein J Org Chem

September 2024

School of Pharmacy and Bioengineering, Keele University, Keele, Staffordshire ST5 5JX, United Kingdom.

A change in mechanism was observed in the hypervalent iodine-mediated cyclization of -alkenylamides when the carbon chain between the alkene and the amide increased from two to three atoms. In the latter case, cyclization at the amide nitrogen to form the pyrrolidine ring was favored over cyclization at the amide oxygen. A DFT study was undertaken to rationalize the change in mechanism of this cyclization process.

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Three-dimensional (3D) cancer models, such as multicellular tumor spheroids (MCTS), are biological supports used for research in oncology, drug development and nanotoxicity assays. However, due to various analytical and biological challenges, the main recurring problem faced when developing this type of 3D model is the lack of reproducibility. When using a 3D support to assess the effect of biologics, small molecules or nanoparticles, it is essential that the support remains constant over time and multiples productions.

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Unveiling Arthropod Responses to Climate Change: A Functional Trait Analysis in Intensive Pastures.

Insects

September 2024

CE3C-Centre for Ecology, Evolution and Environmental Changes, Azorean Biodiversity Group, CHANGE-Global Change and Sustainability Institute, School of Agricultural and Environmental Sciences, University of the Azores, Rua Capitão João d'Ávila, Pico da Urze, 9700-042 Angra do Heroísmo, Portugal.

This study investigates the impact of elevated temperatures on arthropod communities in intensively managed pastures on the volcanic island of Terceira, Azores (Portugal), using a functional trait approach. Open Top Chambers (OTCs) were employed to simulate increased temperatures, and the functional traits of ground dwelling arthropods were analyzed along a small elevation gradient (180-400 m) during winter and summer. Key findings include lower abundances of herbivores, coprophagous organisms, detritivores, and fungivores at high elevations in summer, with predators showing a peak at middle elevations.

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Impaired Upper Airway Muscle Function with Excessive or Deficient Dietary Intake of Selenium in Rats.

Antioxidants (Basel)

September 2024

Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, T12 XF62 Cork, Ireland.

Obstructive sleep apnoea (OSA) involves impaired upper airway muscle function and is linked to several pathologies including systemic hypertension, daytime somnolence and cognitive decline. Selenium is an essential micronutrient that exerts many of its effects through selenoproteins. Evidence indicates that either deficient or excessive dietary selenium intake can result in impaired muscle function, termed nutritional myopathy.

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Catechol/-benzoquinone exchange at gold(iii).

Chem Sci

September 2024

CNRS/Université Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA, UMR 5069) 118 Route de Narbonne 31062 Toulouse Cedex 09 France

Although gold(iii) chemistry has tremendously progressed in the past 2 decades, gold(iii) catecholate complexes remain extremely scarce and underdeveloped. Upon preparation and full characterization of P^C-cyclometalated gold(iii) complexes, we serendipitously uncovered an intriguing catechol exchange process at gold(iii). Electron-rich catecholates turned out to be readily displaced by electron-poor -benzoquinones.

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In this study, a novel method using hydrophilic interaction liquid chromatography (HILIC) coupled with inductively coupled plasma high-resolution mass spectrometry (ICP-HRMS) was introduced for the quantification of phospholipids in oil samples. The method employed a bridged ethyl hybrid (BEH) stationary phase HILIC column with a tetrahydrofuran (THF)/water mobile phase, enhancing the solubility and detection of phospholipids. During the study, a gradient/matrix effect on ICP-HRMS sensitivity was observed and successfully compensated for experimentally, ensuring reliable quantification results.

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Turning black soldier fly rearing by-products into valuable materials: Valorisation through chitin and chitin nanocrystals production.

Carbohydr Polym

November 2024

Universite de Pau et Pays de l'Adour, E2S UPPA, CNRS, IPREM UMR 5254, 64000 Pau, France; MANTA - Marine Materials Research Group, Universite de Pau et des Pays de l'Adour, E2S UPPA, 64600 Anglet, France. Electronic address:

The industry of insect-based proteins as feed and food products has been encountering a huge development since the last decade, and industrial-scale factories are now arising worldwide. Among all the species studied, Black Soldier Fly is one of the most promising and farmed. This rearing activity generates several by-products in the form of chitin-rich biomass that can be valorised to keep a virtuous production cycle embedded in the scope of the bioeconomy.

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Investigating natural processes in arsenic (As) polluted areas and plants that have naturally chosen to grow there pose practical restoration recommendations. This study aimed to assess long-term changes in natural As dendroremediation dynamics for Quercus robur L. and Tilia cordata Mill.

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Porphyrin-silver acetylide cluster catalysts with dual active sites for the electrochemical reduction of CO.

Chem Commun (Camb)

September 2024

Universite de Pau et Pays de l'Adour, E2S UPPA, CNRS, IPREM UMR 5254 Technopole Hélioparc 2 avenue du Président Pierre Angot, 64053 PAU CEDEX 09, France.

A one-step synthesis of porphyrin-silver acetylide clusters from tetra alkyne-substituted porphyrin is described. The solid-state properties of three 2D-like compounds were fully characterised using XPS and XRD while their catalytic properties under CO electroreduction reaction conditions were assessed and their faradaic efficiency quantified.

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Selectivity of a Copper Oxide CO Reduction Electrocatalyst Shifted by a Bioinspired pH-Sensitive Polymer.

ACS Appl Mater Interfaces

August 2024

Universite de Pau et Pays de l'Adour, E2S UPPA, CNRS, IPREM UMR 5254, Technopole Hélioparc, 2 Avenue du Président Pierre Angot, 64053 PAU CEDEX 09, France.

A bioinspired polymeric membrane capable of shifting the selectivity of a copper oxide electrocatalyst in the CO reduction reaction is described. The membrane is deposited on top of copper oxide thin films from wet deposition techniques under controlled conditions of humidity and self-assembles into an arranged network of micrometer-sized pores throughout the polymer cross-section. The membrane was composed of a block copolymer with a precisely controlled ratio of poly-4-vinylpyridine and poly(methyl methacrylate) blocks (PMMA--P4VP).

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Arsenic (As) speciation analysis is scientifically relevant due to the pivotal role the As chemical form plays in toxicity, which, in turn, directly influences the effect it has on the environment. The objective of this study was to develop and optimize a method tailored for studying As compounds in plant samples. Different extraction procedures and HPLC methods were explored to assess their efficiency, determine mass balance, and improve the resolution of compounds in the chromatograms.

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Sulfate-reducing consortium HQ23 stabilizes metal(loid)s and activates biological N-fixation in mixed heavy metal-contaminated soil.

Sci Total Environ

October 2024

School of Water Resource and Environment, Research Center of Environmental Science and Engineering, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, Beijing 100083, PR China.; Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Drive, Ste-Anne-de-Bellevue, Quebec H9X 3V9, Canada.

Article Synopsis
  • Sulfate-reducing bacteria (SRB) can help clean up mine pollution but need more research on how they stabilize heavy metals in low oxygen environments.
  • The study created a new bacterial consortium, HQ23, using SRB and local microbes, confirming the presence of important species through advanced genetic techniques.
  • Results showed HQ23 thrives in low oxygen and varying pH levels, effectively reducing harmful metals in contaminated soils, while also enhancing nitrogen-fixing activity, suggesting it could be valuable for future environmental clean-ups.
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Aerated compost teas (ACTs) are rich in soluble humic substances (SHS) that have high affinity for metals, notably Cu. Using a batch experiment, we measured the extent to which two ACTs altered Cu dynamics in vineyard topsoils one day and 21 days after their addition. Soils were extracted with 0.

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A library of novel structurally related singlet carbenes, namely, acyclic amino(haloaryl)carbenes, was designed by a high-yielding two-step procedure, and their chemical stability explored both experimentally and theoretically. Thanks to a careful selection of both the amino and the aryl substitution pattern, these carbenes exhibit a wide range of stability and reactivity, spanning from rapid self-dimerization for carbenes featuring -F substituents to very high chemical stability as bare carbenes, up to 60 °C for several hours for compounds carrying -Br substituents. Their structure was determined through NMR and X-ray diffraction studies, and their reactivity evaluated in benchmark reactions, highlighting the ambiphilic character of this novel class of singlet carbenes.

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Infiltration of effluents from wastewater treatment plants (WWTP) into groundwater can be a source of Contaminants of Emerging Concern (CECs), such as pharmaceutical compounds, that are not fully removed during the treatment processes. A multi-tracer approach, based on hydrogeochemical, isotopic, and organic tracers, is applied in the Vistrenque Aquifer (Gard, France) to assess the dispersion of such unintentional plumes and its potential implication on groundwater quality for CECs in a small catchment area. In this area, a point source of WWTP effluent causes contaminant infiltration and unintentional transfer to the aquifer.

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A critical review on bioremediation technologies of metal(loid) tailings: Practice and policy.

J Environ Manage

May 2024

School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, 100083, Beijing, China; Université de Pau et des Pays de l'Adour/E2S UPPA, IPREM UMR CNRS 5254, BP 1155, 64013, Pau Cedex, France.

Globally, most high-grade ores have already been exploited. Contemporary mining tends to focus on the extraction of lower-grade ores thereby leaving large stored tailings open to the environment. As a result, current mines have emerged as hotspots for the migration of metal(loid)s and resistance genes, thereby potentially contributing to a looming public health crisis.

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Effects of soil metal(loid)s pollution on microbial activities and environmental risks in an abandoned chemical smelting site.

J Environ Sci (China)

September 2024

School of Water Resources and Environment, Research Center of Environmental Science and Engineering, China University of Geosciences (Beijing), Beijing 100083, China; Equipe Environnement et Microbiologie, MELODY group, Université de Pau et des Pays de l'Adour, E2S-UPPA, IPREM UMR CNRS 5254, BP 1155, 64013 Pau Cedex, France.

Article Synopsis
  • Abandoned chemical smelting sites pose significant environmental risks due to the presence of toxic substances, with soil samples analyzed for metal(loid) content revealing high ecological risk indices that vary with depth.
  • Soil depth D-1 showed the highest risk, primarily attributed to cadmium (Cd), while other metals like arsenic (As) contributed less to the overall risk.
  • The study utilized a modified pollution risk index to assess contamination levels, and findings indicated low microbial activity in heavily contaminated soils, suggesting heavy metal stress impacts on microbial health.
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Ligand-Enabled Oxidative Fluorination of Gold(I) and Light-Induced Aryl-F Coupling at Gold(III).

J Am Chem Soc

April 2024

Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA, UMR 5069) , CNRS/Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, Cedex 09, France.

MeDalphos Au(I) complexes featuring aryl, alkynyl, and alkyl groups readily react with electrophilic fluorinating reagents such as -fluorobenzenesulfonimide and Selectfluor. The ensuing [(MeDalphos)Au(R)F] complexes have been isolated and characterized by multinuclear NMR spectroscopy as well as X-ray diffraction. They adopt a square-planar contra-thermodynamic structure, with F to N.

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Arsenic (As) remediation is challenging due to the complex nature and the persistence of these metalloid compounds. While it may seem that differences between As forms influence have been extensively described, new findings challenge the previously accepted knowledge, particularly for woody plants. Therefore, this study focused on 2-year-old Tilia cordata Mill.

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