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electrochemical Analysis of Zirconiumin Aqueous and Organic Media

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American Journal of Analytical Chemistry 2024年第2期15卷 99-118页

作者： paul Mendy Démo Koita Theodore Tzedakis Cheikhou Kane Codou Guèye Mar-Diop ecole Supérieure Polytechnique Université Cheikh Anta DIOP Dakar Sénégal Laboratoire de Génie Chimique Université de Toulouse III—Paul Sabatier Toulouse France

For the challenging nature of the zirconium environment analysis, this study consists to analyze the electrochemical behavior of Zirconium in both aqueous and organic media. To that end first the electrolytic media was selected on the basis of the Pourbaix potential-pH diagram, which provides informations on the predominance of Zr(IV) ion and Zr in aqueous media. In aqueous media, analyzes were first carried out in acidic media then in basic media. Studies have thus revealed that the acidic environment is not favourable for the electrochemical analysis of zirconium. Voltammograms obtained in an acidic environment show no zirconium detection signal;this is due to the strong presence of H+ ions in the solution. We have also observed in acidic media the phenomenon of passivation of the electrode surface. In aqueous alkaline media (pH = 13), we have drawn in reduction several Intensity-Potential curves by fixingsome technical parameterslike scanning speed, rotation speed of the electrode. The obtained voltammograms show cathodic waves, starting from -1.5 V/DHW and attributed to the reduction of Zr (IV) to Zr (0). The last phase of this study focused on the electrochemical analysis of zirconium in an organic media. In this media, several intensity-potential curves were plotted in reduction and in cyclic voltammetry with various parameters. Through several reduction analysis, the Zr (IV) was reduced to Zr (0) to the potential of -1.5 V/DHW. The electrochemical analysis of zirconium in organic media seems globally easier to achieve thanks to its large solvent window (i.e. dimethylformamide (DMF) solvent window > 6 V).

关键词： Zirconium electrochemical Reduction Cyclic Voltammetry Voltammogram Dymethylformamide

A global analysis of the introduction pathways and characteristics associated with non-native fish species introduction, establishment, and impacts

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ecological Processes 2024年第2期 16-31页

作者： Camille Bernery Céline Bellard Franck Courchamp Sébastien Brosse Boris Leroy CNRS Agro Paris Tech Ecologie Systématique Evolution Université Paris-Saclay Unité Biologie des Organismes et ecosystèmes Aquatiques (BOReA UMR 8067) Muséum National d’Histoire Naturelle Sorbonne Universités Université de Caen Normandie Université des Antilles CNRS IRD Laboratoire évolution & Diversité Biologique (eDB UMR5174) Université Paul Sabatier-Toulouse 3 CNRS IRD UPS

Background The invasion success of introduced freshwater fishes is influenced by many factors, including ecological, species, and socioeconomic characteristics. Most studies that document the importance of these characteristics are conducted at local scales and/or focus on a single step of the invasion process. In this study, we aim to determine the species characteristics, ecological characteristics, and socioeconomic characteristics of non-native freshwater fish invasions. Our assessment was done at the global scale and considers all three steps of the invasion(i.e., introduction, establishment, and impact). For this purpose, we applied generalized linear models to 20 variables collected for 307 non-native species and modeled them as a function of ecological characteristics(i.e., environmental features), species traits(i.e., functional and morphological), and socioeconomic characteristics(i.e., human use and introduction pathways). We considered the number of countries in which each species was introduced, established, or had ecological impacts as a proxy of invasion step success. We also explored the specifics of species introduced through the aquaculture and the ornamental fish trade *** We found that non-native freshwater fishes with broad diets, high parental care, and multiple introduction pathways are the most widely introduced and established worldwide. The number of countries with impacts reported was best explained by the type of introduction pathway(i.e., aquaculture or fisheries). Moreover, among non-native species introduced through aquaculture, those belonging to Cypriniformes and having broad diets were the most widely introduced and established species. In contrast, the species introduced through the ornamental fish trade pathway belonged to various taxonomic orders but were mainly native to tropical *** Considering several types of factors is important when analyzing the invasion success of freshwater fish and disentang

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Generation,bonding and reactivity of transient zinc-substituted silylenes

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Science China Chemistry 2024年第4期67卷 1256-1262页

作者： Cheng Xu Thayalan Rajeshkumar Laurent Maron Xuebing Leng Yaofeng Chen State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032China Spin-X Institute School of Chemistry and Chemical EngineeringState Key Laboratory of Luminescent Materials and DevicesGuangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional MaterialsSouth China University of TechnologyGuangzhou 510641China LPCNO CNRS&INSAUniversitéPaul SabatierToulous 31077France

The metal-substituted silylenes are of high interest,as the theoretical studies indicated that the silylenes with electropositive substituents have a small Δe_(S-T)(singlet-triplet energy gap)or even the ground-state ***,such compounds are highly unstable,and only two transient alkali metal-substituted silylenes M(^(t)Bu_(3)Si)Si:(M=Li,K)were generated by photoextrusion of the alkali metal-substituted silacyclopropenes and merely studied by spectroscopic method(ePR)at low temperature(14 to 50 K).Herein,we report the generation of transient zinc-substituted silylenes from zinc silacyclopropanyl complexes under very mild and convenient *** generated transient zinc-substituted silylenes are highly reactive and undergo intermolecular cycloaddition with alkenes for the synthesis of zinc-substituted Si-heterocyclic *** there is no substrate,the zinc-substituted silylenes attack the C-C bonds of the β-diketiminato ligands and break the C-C *** studies further highlight the silylene nature of the zinc-substituted silylene and a very small Δe_(S-T)(4.4 kcal/mol).

关键词： zinc complex silylene C-C bond cleavage cycloaddition DFT calculations

Associations between physical activity levels and ATPase inhibitory factor 1 concentrations in older adults

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Journal of Sport and Health Science 2024年第3期13卷 409-418页

作者： Jérémy Raffin Yves Rolland Annelise Genoux Guillaume Combes Mikael Croyal Bertrand Perret Sophie Guyonnet Bruno Vellas Laurent O.Martinez Philipe de Souto Barreto For the MAPT/DSA Group Institut du Vieillissement Gérontopôle de ToulouseCentre Hospitalo-Universitaire de ToulouseToulouse 31000France Centre d'epidémiologie et de Recherche en Santédes Populations UnitéMixte de Recherche 1295Institut National de la Santéet de la Recherche MédicaleUniversitéToulouse-III-Paul-SabatierToulouse 31000France LimitAging Team Institut des Maladies Métaboliques et CardiovasculairesUnitéMixte de Recherche 1297Institut National de la Santéet de la Recherche MédicaleUniversitéToulouse III-Paul SabatierToulouse 31432France Service de Biochimie Pôle de biologieHôpital de PurpanCentre Hospitalo-Universitaire de ToulouseToulouse 31300France L'Institut du Thorax Institut National de la Santéet de la Recherche MédicaleCentre National de la Recherche ScientifiqueCentre Hospitalo-Universitaire de NantesNantes UniversitéNantes 44000France BioCore US16Structure Fédérative de Recherche BonamyInstitut National de la Santéet de la Recherche MédicaleCentre National de la Recherche ScientifiqueCentre Hospitalo-Universitaire de NantesNantes UniversitéNantes 44000France Plate-forme de spectrométrie de masse Centre de Recherche en Nutrition HumaineOuestNantes 44000France 不详

Background:Adenosine triphosphatase inhibitory factor 1(IF1)is a key protein involved in energy ***1 has been linked to various agerelated diseases,although its relationship with physical activity(PA)remains ***,the apolipoprotein A-I(apoA-I),a PA-modulated lipoprotein,could play a role in this relationship because it shares a binding site with IF1 on the cell-surface ATP *** examined here the associations between chronic PA and plasma IF1 concentrations among older adults,and we investigated whether apoA-I mediated these ***:In the present work,1096 healthy adults(63.8%females)aged 70 years and over who were involved in the Multidomain Alzheimer Prevention Trial study were ***1 plasma concentrations(square root of ng/mL)were measured at the 1-year visit of the Multidomain Alzheimer Prevention Trial,while PA levels(square root of metabolic equivalent task min/week)were assessed using questionnaires administered each year from baseline to the 3-year *** linear regressions were performed to investigate the associations between the first-year mean PA levels and IF1 *** analyses were conducted to examine whether apoA-I mediated these *** linear regressions were carried out to investigate whether the 1-year visit IF1 concentrations predicted subsequent changes in ***:Multiple linear regressions indicated that first-year mean PA levels were positively associated with IF1 concentrations(B=0.021;Se=0.010;p=0.043).Mediation analyses revealed that about 37.7%of this relationship was mediated by apoA-I(B_(ab)=0.008;Se=0.004;p=0.023).Longitudinal investigations demonstrated that higher concentrations of IF1 at the 1-year visit predicted a faster decline in PA levels over the subsequent 2 years(time×IF1:B=0.148;Se=0.066;p=0.025).Conclusion:This study demonstrates that regular PA is associated with plasma IF1 concentrations,and it suggests that apoA-I partly med

关键词： Aging Apolipoprotein Bioenergetics exerkine Mitochondria

强磁场下Cu−Co难混溶合金凝固过程中晶体取向和性能的调控

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Transactions of Nonferrous Metals Society of China 2024年第6期34卷 1878-1892页

作者：魏晨李金山闫育洁贺一轩 eric BeAUGNON 王军西北工业大学凝固技术国家重点实验室西安710072 Univ.Grenoble Alpes INSA ToulouseUniv.Toulouse Paul SabatierEMFLCNRSLNCMI38000 GrenobleFrance

对Cu50Co50合金在不同磁场强度下进行非平衡凝固实验,研究富钴相的取向、显微组织演化和磁性能。结果表明,凝固后相分离的棒状富钴相可以实现排列形态,在5 T强磁场下富钴相的晶体取向为111平行磁场方向。然而,发生二次液−液相分离的富... 详细信息

对Cu50Co50合金在不同磁场强度下进行非平衡凝固实验,研究富钴相的取向、显微组织演化和磁性能。结果表明,凝固后相分离的棒状富钴相可以实现排列形态,在5 T强磁场下富钴相的晶体取向为111平行磁场方向。然而,发生二次液−液相分离的富铜相的取向没有受到HMF的显著影响。在0 T磁场下凝固的合金表现出近磁各向同性行为,而在5 T磁场下凝固的合金则表现出磁各向异性行为。合金的饱和磁化强度略有增加,矫顽力相应降低,这与富钴晶体的取向演化行为密切相关。

关键词：强磁场显微组织演化铜钴合金相分离磁性能

Nile tilapia(Oreochromis niloticus) invasion impacts trophic position and resource use of commercially harvested piscivorous fishes in a large subtropical river

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ecological Processes 2023年第2期12卷 98-114页

作者： Fangmin Shuai Jie Li Sovan Lek Pearl River Fisheries Research Institute CAFS université de Toulouse-paul sabatier

Background Although freshwater ecosystems cover less than 1% of the earth's surface, they support extremely high levels of biodiversity and provide vital ecosystem services. However, due to the introduction of non-native fishes, aquatic ecosystem functioning has been altered, and in some cases, declined sharply. Quantifying the impacts of invasive species has proven problematic. In this study, we examined the relative trophic position of native piscivorous fishes to estimate the effects of invasive Nile tilapia on food webs in the downstream sections of an invaded large subtropical river, the Pearl River, China. Furthermore, we quantified how native piscivorous fish diets changed as the Nile tilapia invasion *** The trophic position of the widely distributed and locally important economically harvested piscivorous culter fish(Culter recurviceps), mandarinfish(Siniperca kneri), and catfish(Pelteobagrus fulvidraco) lowered significantly in the invaded Dongjiang River compared to an uninvaded reference Beijiang River. The lower trophic position of these piscivorous fishes was reflected by a major reduction in the proportion of prey fish biomass in their diets following the Nile tilapia invasion. Small fishes in the diet of culter fish from the reference river(33% small fishes, 17% zooplankton) shifted to lower trophic level zooplankton prey in the invaded river(36% zooplankton, 25% small fish), possibly due to the presence of Nile tilapia. Additionally, small fishes in the diet of mandarinfish in the reference river(46% small fishes, 11% aquatic insects) declined in the invaded river(20% aquatic insects, 30% small fishes). Similarly, the diet of catfish from the reference river shifted from fish eggs(25% fish eggs, 25% aquatic insects) to aquatic insects in the invaded river(44% aquatic insects, 5% fish eggs).Conclusions The results of this study contributed to a growing body of evidence, suggesting that Nile tilapia can modify trophic interactions in in

关键词： Nile tilapia Invasion Stable isotope ratio Trophic position Stable isotope mixing model

Nile tilapia(Oreochromis niloticus) invasion impacts trophic position and resource use of commercially harvested piscivorous fishes in a large subtropical river

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ecological Processes 2023年 313-329页

作者： Fangmin Shuai Jie Li Sovan Lek Pearl River Fisheries Research Institute CAFS université de Toulouse-paul sabatier

Background Although freshwater ecosystems cover less than 1% of the earth's surface, they support extremely high levels of biodiversity and provide vital ecosystem services. However, due to the introduction of non-native fishes,aquatic ecosystem functioning has been altered, and in some cases, declined sharply. Quantifying the impacts of invasive species has proven problematic. In this study, we examined the relative trophic position of native piscivorous fishes to estimate the effects of invasive Nile tilapia on food webs in the downstream sections of an invaded large subtropical river, the Pearl River, China. Furthermore, we quantified how native piscivorous fish diets changed as the Nile tilapia invasion *** The trophic position of the widely distributed and locally important economically harvested piscivorous culter fish(Culter recurviceps), mandarinfish(Siniperca kneri), and catfish(Pelteobagrus fulvidraco) lowered significantly in the invaded Dongjiang River compared to an uninvaded reference Beijiang River. The lower trophic position of these piscivorous fishes was reflected by a major reduction in the proportion of prey fish biomass in their diets following the Nile tilapia invasion. Small fishes in the diet of culter fish from the reference river(33% small fishes, 17% zooplankton)shifted to lower trophic level zooplankton prey in the invaded river(36% zooplankton, 25% small fish), possibly due to the presence of Nile tilapia. Additionally, small fishes in the diet of mandarinfish in the reference river(46% small fishes, 11% aquatic insects) declined in the invaded river(20% aquatic insects, 30% small fishes). Similarly, the diet of catfish from the reference river shifted from fish eggs(25% fish eggs, 25% aquatic insects) to aquatic insects in the invaded river(44% aquatic insects, 5% fish eggs).Conclusions The results of this study contributed to a growing body of evidence, suggesting that Nile tilapia can modify trophic interactions in inva

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Functional responses to deforestation in fish communities inhabiting neotropical streams and rivers

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ecological Processes 2023年第4期12卷 74-90页

作者： Isabel Cantera Céline Jézéquel Tony Dejean Jér?me Murienne Régis Vigouroux Alice Valentini Sébastien Brosse Department of environmental Science and Policy Università degli Studi di Milano Laboratoire evolution et Diversité Biologique UMR5174-Université Paul Sabatier CNRS IRD SPYGeN HYDReCO Laboratoire Environnement de Petit Saut

Background Deforestation is a widespread disturbance for neotropical freshwater ecosystems. While biodiversity declines have been associated with deforestation, its functional consequences for stream and river fish faunas remain poorly understood. In this study, we explored how deforestation affects the different facets of the functional structure of fish communities inventoried using environmental DNA metabarcoding in 64 river and 35 stream sites of French Guiana. Specifically, we investigated how functional richness, divergence, evenness and identity of fish faunas are affected by *** We showed that anthropogenic disturbances in French Guiana are modifying the functional diversity of freshwater fish communities. These disturbances not only affected the amount of functional traits held by the communities but also the identity of the traits and the internal structure of the functional space. Consequently, different facets of the functional diversity supported by fish assemblages were altered. In streams, deforestation did not affect the overall diversity of traits but reduced functional redundancy, underlined by a shift in functional identity towards assemblages dominated by pelagic detritivores. In contrast, river fish faunas experienced a decline in functional richness, paired with shifts in functional identity and a loss of fish species with extreme *** The response to deforestation differed between streams and rivers, but it supports the hypothesis that deforestation is linked to functional changes in fish assemblages. By diminishing the range of the functions in rivers or by jeopardizing the redundancy of functions in streams, deforestation could severely hamper the functioning and stability of neotropical freshwater ecosystems.

关键词： eDNA Traits Functional space Richness Divergence evenness Identity Gold mining

Bounded critical Fatou components are Jordan domains for polynomials

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Science China Mathematics 2022年第2期65卷 331-358页

作者： Pascale Roesch Yongcheng Yin Institut de Mathematiques de Toulouse Universite Paul SabatierToulouse 31062France School of Mathematical Sciences Zhejiang UniversityHangzhou 310027China

We prove that any bounded Fatou component of a polynomial of degree at least two, which is not(eventually) a Siegel disk, is a Jordan domain.

关键词： Fatou component Jordan domain puzzle local connectivity