1,259 results match your criteria: "Universite de Pau et des Pays de L'Adour[Affiliation]"

Lysozyme-responsive nanoparticles were fabricated using a hydrophilic protein (gelatin type A) as the core and a hydrophobic polysaccharide (chitosan) as the shell. In this study, curcumin was used as a model molecule for encapsulation and promoted the aggregation of gelatin nanoparticles. Transglutaminase catalyzed both intra-molecular cross-linking within gelatin and inter-molecular cross-linking between gelatin and chitosan.

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The selection of best variables is a challenging problem in supervised and unsupervised learning, especially in high-dimensional contexts where the number of variables is usually much larger than the number of observations. In this paper, we focus on two multivariate statistical methods: principal components analysis and partial least squares. Both approaches are popular linear dimension-reduction methods with numerous applications in several fields including in genomics, biology, environmental science, and engineering.

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The formulation of safe electrolytes for supercapacitors based on phosphazene used as a flame-retardant (FR) is carried out. 3 molecules are used: hexafluorocyclotriphosphazene (FR1), (ethoxy)pentafluorocyclotriphosphazene (FR2) and pentafluoro(phenoxy)cyclotriphosphazene (FR3). A comparative study on the efficacy from a safety point of view is performed to determine the minimum percentages of each to be used in a conventional acetonitrile (ACN)/1.

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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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Introduction: The aim was to compare the fatiguing effects induced by continuous (CONT) and intermittent (INT) tasks of an identical duration by equating the force-time integral.

Method: ː Fourteen men performed two sequences (4 blocks of 378s) of contractions (CONT or INT) of the quadriceps femoris. The CONT contraction of 378s corresponded to 10% of the maximum voluntary muscle contraction (MVC).

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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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Phytostabilization is an important way for the remediation of mine tailings, but the associated microbial processes and community succession remain largely unknown. In this study, we investigated the assembly mechanisms maintaining the core and satellite subcommunities diversity during phytostabilizaion of a mercury-rich mine tailings. The contents of total Hg and methylmercury decreased with a concomitant increase of total and available phosphorus content along the successive remediation stages.

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Perspectives on using peat records to reconstruct past atmospheric Hg levels.

J Hazard Mater

November 2024

Institute of Geography and Oeschger Center for Climate Change Research, University of Bern, Bern 3012, Switzerland.

Anthropogenic mercury (Hg) emissions to the atmosphere have increased the concentration of this potent neurotoxin in terrestrial and aquatic ecosystems. The magnitude of regional variation in atmospheric Hg pollution levels raises questions about the interactions between natural processes and human activities at local and regional scales that are shaping global atmospheric Hg cycling. Peatlands are potentially valuable and widespread records of past atmospheric Hg levels that could help address these questions.

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Long-chain polyunsaturated fatty acids (LC-PUFA) like arachidonic acid (ARA, 20:4n-6), eicosapentaenoic acid (EPA, 20:5n-3), and docosahexaenoic acid (DHA, 22:6n-3) constitute one-third to half of fish sperm lipids. Fish sperm is rich in phospholipid (PL)-primarily phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin. DHA is generally the most abundant LC-PUFA in each PL class, followed by competition between ARA and EPA.

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Marshes are wetlands known for providing major ecosystem services in terms of water quality and human activities. These ecosystem services are mainly provided by marshes' benthic community, composed of prokaryotes (bacteria and archaea) but also of eukaryotes (micro-eukaryotes and meiofauna). The aim of this study is to (1) assess the environmental parameters affecting benthic community composition in marshes, (2) highlight the associations between organisms from the three domains of life, and (3) determine the parameters controlling these associations.

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Agricultural organic wastes can leach dissolved organic matter (DOM) into surrounding water bodies, establishing them as significant sources of aquatic DOM. Given the importance of DOM in biogeochemical cycling of mercury (Hg), this DOM may mediate divalent Hg (Hg(II)) reduction, a process that remains poorly understood. This study investigated Hg(II) reduction using DOM derived from six representative agricultural wastes, categorized into livestock manure (chicken, pig, cow) and crop straw (rice, corn, rapeseed), with systematic considerations of the kinetics of reduction processes and the involvement of key free radicals.

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In this review, selected examples are presented to demonstrate how microfluidic approaches can be utilized for investigating microbial life from deep geological environments, both from practical and fundamental perspectives. Beginning with the definition of the deep underground biosphere and the conventional experimental techniques employed for these studies, the use of microfluidic systems for accessing critical parameters of deep life in geological environments at the microscale is subsequently addressed (high pressure, high temperature, low volume). Microfluidics can simulate a range of environmental conditions on a chip, enabling rapid and comprehensive studies of microbial behavior and interactions in subsurface ecosystems, such as simulations of porous systems, interactions among microbes/microbes/minerals, and gradient cultivation.

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Use of H-labeled nanoplastics to study their accumulation and toxicity in Daphniamagna.

Chemosphere

November 2024

Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), UMR5254, Hélioparc, 64053, Pau, France. Electronic address:

Understanding the interactions between nanoplastics (NP) and biota is essential for risk assessment. However, NP quantification in complex matrices remains a challenge, especially when they are not labeled. Most labeling strategies consists in adding another compound (fluorophore, metal, lanthanide …) to the polymer, which can alter the NP properties and poses a risk of leaching phenomena.

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Article Synopsis
  • The text discusses a method for analyzing survival data where some patients may never experience the event of interest, using a mixture cure Cox model and an accelerated failure time (AFT) model when applicable.
  • It introduces a penalized likelihood technique to estimate mixture cure semi-parametric AFT models, which accounts for various types of censored data and uses Gaussian basis functions for baseline hazard estimation.
  • The method's efficacy is validated through simulation studies and a real case study on melanoma recurrence, showcasing its advantages over existing methods like the smcure R package and making it accessible via the aftQnp R package.
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Charge as a key physicochemical factor in adsorption of organic micropollutants from wastewater effluent by rice husk bio-silica.

Water Res

January 2025

Analytical Chemistry Group, Department of Plant and Environmental Science, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg 1871, Denmark.

Wastewater treatment plants (WWTPs) often fail to fully remove organic micro-pollutants (OMPs), necessitating advanced treatment methods. This study examines the potential of an agricultural waste-derived adsorbent, rice husk (RH) - silica, for removing a complex mixture of 20 OMPs in MilliQ water and wastewater effluent. While RH-silica shows potential for OMP removal, its performance with multicomponent mixtures in real wastewater has yet to be investigated.

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Methylmercury degradation by hot spring sulfur-linked microbial communities as a dominant pathway in regulating mercury speciation.

Water Res

January 2025

Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), Pau 64000, France. Electronic address:

Sulfidic hot springs harbor unique microbial communities and are important in mercury (Hg) species transformations, although the fine scale drivers of these processes remain poorly understood. Here we studied Hg speciation in water, biofilms, and sediment across three sampling seasons in a French sulfidic hot spring with low Hg concentrations. Microbial Hg species methylation and demethylation potentials were evaluated using incubation experiments with species-specific Hg isotope tracers.

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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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In the past few years, there has been an increasing interest in mycosporines-UV-absorbing molecules-bringing important insights into their intrinsic properties as natural sunscreens. Herein, mycosporine-serinol and gadusol (enolate form)/gadusolate were exposed to UV radiation via a solar simulator and the photostability was assessed in pure water and different natural matrices like river, estuary and ocean water. In general, this study revealed that the photodegradation of gadusolate and mycosporine-serinol was higher in natural matrices than in pure water due to the generation of singlet oxygen on UV irradiation.

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Over the next few years, it is planned to convert all or part of the underground gas storage (UGS) facilities used for natural gas (salt caverns, depleted hydrocarbon reservoirs, and deep aquifers) into underground dihydrogen (H2) storage reservoirs. These deep environments host microbial communities, some of which are hydrogenotrophic (sulfate reducers, acetogens, and methanogens). The current state of microbiological knowledge is thus presented for the three types of UGS facilities.

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Unravelling the metabolomic signatures of migrant and non-migrant glass eels (Anguilla anguilla) and their response to diazepam exposure.

Mar Environ Res

November 2024

Department of Analytical Chemistry, University of the Basque Country, 48080 Leioa (Biscay), Basque Country, Spain; Plentzia Marine Station, University of the Basque Country, 48620 Plentzia (Biscay), Basque Country, Spain.

Understanding the migratory cycle of the European eel is crucial for implementing effective conservation measures. The reasons why some glass eels settle in lower estuaries rather than migrating upriver remain unclear. This study aims to identify metabolomic signatures that distinguish active (migrant) from inactive (non-migrant) glass eels.

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Effects of refeeding with low- or high-carbohydrate diets on intermediary carbohydrate metabolism in juvenile and adult Nile tilapia.

Animal

November 2024

School of Animal Technology and Innovation, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand. Electronic address:

Generally, energy expenditure and compensation according to food deprivation and refeeding often occur along the life cycle of farmed-raised fish. Fasting and refeeding are also hypothesised to modulate carbohydrate metabolism particularly for herbivorous and/or omnivorous. This study aims to investigate the effects of short-term fasting and subsequent refeeding with high or low-carbohydrate diets on the intermediary carbohydrate metabolism of juvenile and adult Nile tilapia (Oreochromis niloticus) which is known to be a good user of carbohydrate as an energy source.

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Article Synopsis
  • * The Ne/Nc ratio varies due to ecological and evolutionary factors, influencing conservation strategies, and different types of effective population sizes must be considered to grasp their implications.
  • * Despite technological advancements in marine species documentation, predicting the Ne/Nc ratio remains challenging, highlighting the need for more research to effectively manage genetic diversity and population viability in these fish populations.
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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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