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This study investigates the applicability of elemental and Cu isotope compositions in sediments and bivalves from the Korean coast to monitor anthropogenic Cu contamination. Sediments with high Cu (>64.4 mg/kg) and/or moderate enrichment levels (EF Cu) exhibit homogenous δ65Cu AE647 values (−0.12 to +0.16 ‰), suggesting similar anthropogenic Cu fingerprints along the Korean coast. Sediments with Cu concentrations near natural background levels (< 20.6 mg/kg) display large isotopic variability (Δ65Cu max-mim : ~0.8 ‰), encompassing those from sediments under anthropic influences. We hypothesize that Cu isotopic compositions of Korean geology are heterogeneous, therefore, natural end-members of source mixing models should be established locally at small scales. Cu concentrations in Oysters correlate with sediments, and their isotopic compositions are more suitable for monitoring Cu contamination, while mussel's regulatory mechanisms seem to affect source records. The current Cu isotope data will help to detect shifts attributable to anthropic contamination in future biomonitoring. [Display omitted] • Pristine sediments show a wide range of Cu isotope compositions. • Contaminated sediments tend to have lower Cu isotope ratios. • Overlap of natural and anthropic Cu isotope ranges challenge source discrimination. • Oysters mirror sediment trends and are suitable for monitoring Cu contamination. • Cu source discrimination requires a prior local definition of end-members. [ABSTRACT FROM AUTHOR]

Marinas are central hubs of global maritime leisure and transport, yet their operations can deteriorate the environmental quality of sediments. In response, this study investigated the metal contamination history associated with antifouling paint uses in a sediment core collected from Bracuhy marina (Southeast Brazil). Analysis target major and trace elements (Cu, Zn, Pb, Cd and Sn), rare earth elements (REEs), and Pb isotopes. The modification in Pb isotopic ratios and REEs pattern unequivocally revealed sediment provenance disruption following the marina construction. Metal distribution in the sediment core demonstrates that concentrations of Cu and Zn increased by up to 15 and 5 times, respectively, compared to the local background. This severe Cu and Zn contamination coincides with the onset of marina operations and can be attributed to the use of antifouling paints. [Display omitted] • Sediment provenance changed following the marina construction. • Rare Earth Elements coupled with Pb isotopes indicate disruption in sedimentary dynamics. • Cu and Zn contamination from antifouling paints begins post marina operation. • Cu enrichment in sediment is 15 times the local natural background. [ABSTRACT FROM AUTHOR]

Zinc (Zn) isotope compositions in soft mussel tissues help identify internal biological processes and track coastal Zn sources in coastal environments, thus aiding in managing marine metal pollution. This study investigated the seasonal and multi-decadal Zn isotope compositions of blue mussels (genus Mytilus) from two French coastal sites with contrasting Zn environmental contamination. Concurrently, we characterized the isotope ratios of sediments and plankton samples at each site to understand the associations between organisms and abiotic compartments. Our primary objective was to determine whether these isotope compositions trace long-term anthropogenic emission patterns or if they reflect short-term biological processes. The multi-decadal isotope profiles of mussels in the Loire Estuary and Toulon Bay showed no isotope variations, implying the enduring stability of the relative contributions of natural and anthropogenic Zn sources over time. At seasonal scales, Zn isotope ratios were also constant; hence, isotope effects related to spawning and body growth were not discernible. The multi-compartmental analysis between the sites revealed that Toulon Bay exhibits a remarkably lower Zn isotope ratio across all studied matrices, suggesting the upward transfer of anthropogenic Zn in the food web. In contrast, the Zn isotope variability observed for sediments and organisms from the Loire Estuary fell within the natural baseline of this element. In both sites, adsorptive geogenic material carrying significant amounts of Zn masks the biological isotope signature of plankton, making it difficult to determine whether the Zn isotope ratio in mussels solely reflects the planktonic diet or if it is further modified by biological homeostasis. In summary, Zn isotope ratios in mussels offer promising avenues for delineating source-specific isotope signatures, contingent upon a comprehensive understanding of the isotope fractionation processes associated with the trophic transfer of this element through the plankton. [Display omitted] • Pristine and contaminated sites show samples with distinct isotope fingerprints. • Systematic lighter δ66Zn values identify anthropogenic Zn in contaminated samples. • Zn isotopes trace upward transfer of anthropogenic Zn in the food web. • Isotope biomonitoring indicates no alterations in Zn sources over four decades. • Zn isotope ratio constancy at seasonal scale discards biological isotope effects. [ABSTRACT FROM AUTHOR]

Zinc (Zn) and copper (Cu) stable isotopic compositions have been analyzed in various species of bivalve mollusks worldwide, but no comprehensive systematic interspecies comparison exists. Thus, we assessed isotope differences between species harvested in emblematic French coastal ecosystems to unveil biologically driven Cu and Zn isotope fractionation patterns. Inter-species isotopic variability of Cu is larger than Zn, with organisms that regulate internal concentrations displaying preferential bioaccumulation of heavy isotopes. The degree of internal isotope fractionation decreases from mussels > clams > oysters, affecting Cu more than Zn. The less pronounced Zn inter-specie variability helps preserve source information more reliably. Spatial analysis of a single oyster species denotes thus an important isotope variability of environmental Zn sources, including natural, anthropogenic and dietary components. Overall, results highlight the importance of considering systematic offset in Cu and Zn isotope values when comparing data from different bivalve species. [Display omitted] • Cu and Zn isotope differences between bivalve mollusks species were studied. • Inter-species isotopic variability of Cu is larger than Zn. • The degree of internal isotope fractionation decreases from mussels > clams > oysters. • Low Zn inter-specie variability helps preserve source information more reliably. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sequenced mitogenomes of the species Phellinotus piptadeniae and Trametes villosa. • Variation in mtDNA size is due to non-coding regions, introns, HEGs, and uORFs. • Possible existence of horizontal gene transfer events mediated by the activity of HEGs. • GC content may be used to distinguish coding from non-coding sequences. • Mitochondrial genes in the nuclear genome are not common in Agaricomycetes. The mitochondrion is an organelle found in eukaryote organisms, and it is vital for different cellular pathways. The mitochondrion has its own DNA molecule and, because its genetic content is relatively conserved, despite the variation of size and structure, mitogenome sequences have been widely used as a promising molecular biomarker for taxonomy and evolution in fungi. In this study, the mitogenomes of two fungal species of Agaricomycetes class, Phellinotus piptadeniae and Trametes villosa , were assembled and annotated for the first time. We used these newly sequenced mitogenomes for comparative analyses with other 55 mitogenomes of Agaricomycetes available in public databases. Mitochondrial DNA (mtDNA) size and content are highly variable and non-coding and intronic regions, homing endonucleases (HEGs), and unidentified ORFs (uORFs) significantly contribute to the total size of the mitogenome. Furthermore, accessory genes (most of them as HEGs) are shared between distantly related species, most likely as a consequence of horizontal gene transfer events. Conversely, uORFs are only shared between taxonomically related species, most probably as a result of vertical evolutionary inheritance. Additionally, codon usage varies among mitogenomes and the GC content of mitochondrial features may be used to distinguish coding from non-coding sequences. Our results also indicated that transposition events of mitochondrial genes to the nuclear genome are not common. Despite the variation of size and content of the mitogenomes, mitochondrial genes seemed to be reliable molecular markers in our time-divergence analysis, even though the nucleotide substitution rates of mitochondrial and nuclear genomes of fungi are quite different. We also showed that many events of mitochondrial gene shuffling probably happened amongst the Agaricomycetes during evolution, which created differences in the gene order among species, even those of the same genus. Altogether, our study revealed new information regarding evolutionary dynamics in Agaricomycetes. [ABSTRACT FROM AUTHOR]

The Paraiba do Sul (PSR) and Guandu Rivers (GR) water diversion system (120 km long) is located in the main industrial pole of Brazil and supplies drinking water for 9.4 million people in the metropolitan region of Rio de Janeiro. This study aims to discern the trace metals dynamics in this complex aquatic system. We used a combined approach of geochemical tools such as geochemical partitioning, Zn isotopes signatures, and multivariate statistics. Zinc and Pb concentrations in Suspended Particulate Matter (SPM) and sediments were considerably higher in some sites. The sediment partition of As, Cr, and Cu revealed the residual fraction (F4) as the main fraction for these elements, indicating low mobility. Zinc and Pb were mostly associated with the exchangeable/carbonate (F1) and the reducible (F2) fractions, respectively, implying a higher susceptibility of these elements to being released from sediments. Zinc isotopic compositions of sediments and SPM fell in a binary mixing source process between lithogenic (δ66/64Zn JMC ≈ + 0.30‰) and anthropogenic (δ66/64Zn JMC ≈ + 0.15‰) end members. The lighter δ66/64Zn JMC values accompanied by high Zn concentrations in exchangeable/carbonate fraction (ZnF1) enable the tracking of Zn anthropogenic sources in the studied rivers. Overall, the results indicated that Hg, Pb, and Zn had a dominant anthropogenic origin linked to the industrial activities, while As, Cr, and Cu were mainly associated with lithogenic sources. This work demonstrates how integrating geochemical tools is valuable for assessing geochemical processes and mixing source effects in anthropized river watersheds. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• HAV and HEV prevalence and potential risk factors in a rural township of southeastern Brazil. • Declining HAV seroprevalence correlates with age. • HEV seroprevalence is higher than previously shown in Brazilian surveys. • Wantai and Mikrogen ELISA yield comparable seroprevalence results. Hepatitis A virus (HAV) infection is considered highly endemic in Brazil, especially in low-income areas. In contrast, only a few human cases of hepatitis E have been reported. This study aimed to estimate the prevalence and potential risk factors of HAV and hepatitis E virus (HEV) infections in an adult population from a rural township of southeastern Brazil. We conducted a cross-sectional survey using serum samples from urban and rural residents of Cássia dos Coqueiros, São Paulo state. A total of 990 samples were tested for anti-HAV IgG by chemiluminescent microparticle immunoassay, and a subset of 248 samples tested for anti-HEV IgG, using two commercial ELISA. Variables associated with anti-HAV and anti-HEV positivity were assessed by a multivariate analysis using a binomial logistic regression model. Seroprevalence of HAV and HEV was 89.1% and 20.7%, respectively. Age was significantly associated with HAV infection. Wantai and Mikrogen ELISA yielded comparable HEV seroprevalence results. Anti-HAV seroprevalence has declined and correlates with age, whereas anti-HEV was significantly higher than that found in previous population-based studies. These results indicate a need for further investigations of the magnitude of HEV infection in Brazil using the currently available, more sensitive diagnostic methods. [ABSTRACT FROM AUTHOR]

The mid-20th century industrial peak caused severe global lead (Pb) marine contamination. Although Europe initiated Pb emission reduction regulations in the 1980s, the short- and long-term impacts remain unclear. This study investigates the evolution of Pb contamination on the French coast through elemental and isotope analysis in oysters and mussels from the French "Mussel Watch" Program. Observations at 114 monitoring stations over four decades have shown decreasing Pb levels in these bivalve mollusks. In 1988, 95 % exceeded the background reference values; this level had dropped to 39 % by 2021. The Pb isotope ratios in bivalves from eight target sites revealed a reduction in bioaccumulated anthropogenic Pb, albeit without complete elimination. The long residence time of legacy Pb combined with inputs from diffuse urban sources likely explains the persistent presence of anthropogenic Pb on the French coast. This study endorses the importance of continuous biomonitoring to evaluate environmental regulations and policies. [Display omitted] • In 1988, Pb in bivalves exceeded background reference values at 95 % of stations. • In 2021, only 39 % of stations exceeded background reference values. • Isotope analysis revealed reduced bioaccumulated anthropogenic Pb over four decades. • Pb data demonstrated the effectiveness of implemented Pb regulatory measures. • Persisting legacy Pb and diffuse urban Pb sources require continuous biomonitoring. [ABSTRACT FROM AUTHOR]

This study investigates the chronology of copper (Cu) contamination and its stable isotopes within an emblematic Brazilian mangrove impacted by multiple urban and industrial Cu sources, deforestation, and eutrophication. In particular, it tests Cu isotopes as tracers of anthropogenic inputs into an anthropized watershed impacted by multiple sources. To do so, we used multi-isotopic approaches (δ65Cu, δ13C, and δ15N), elemental analyses (Al, Ca, Fe, P, Cu, C, and N), and selective and sequential extractions in a210Pb-dated sediment core. This geochemical "toolbox" allowed identifying two main stages of Cu evolution in the sediment core. In the first stage, before 1965, Cu isotope fingerprints responded to landscape changes, indicating a shift from marine to geogenic dominance due to the remobilization and erosion of terrestrial materials. In the second stage, after 1965, the sediment geochemical profile showed increased Cu total concentrations with a higher bioavailability (as reflected by sequential extraction data) accompanying changes in Cu isotope signatures towards anthropogenic values. The findings evidence that local industrial sources, possibly combined with diffuse urban sources, export Cu into downstream mangroves with a distinguishable isotope signature compared to natural values. This study demonstrates the applicability of Cu isotopes as new environmental forensic tools to trace anthropogenic sources in mangrove sediments. Incorporated into a robust geochemical toolbox that combines inorganic and organic proxies for sedimentary materials, this new tool provides a comprehensive understanding of Cu dynamics in mangrove ecosystems, shedding light on the historical and current sources of Cu. [Display omitted] • Chronological survey of a well-constrained Brazilian mangrove core. • Cu isotopes respond to shifts from marine to geogenic dominance. • Sediments record the evolution of Cu fluxes along periods of urban and industrial development. • Mangrove sediments record anthropogenic Cu isotope fingerprint. • Anthropogenic inputs yielding increased bioavailability of Cu in mangrove sediments. [ABSTRACT FROM AUTHOR]

The behavior, and history of lead (Pb) contamination in the ecosystem of the Loire estuary was examined using elemental concentrations and Pb isotope data in water, sediment, bivalves, shrimps, and fish. In the estuary and in the surrounding coastal area, Pb concentrations in water and sediment decreased compared to concentrations determined in the 1980s, with concentrations ranging from 15.8 to 65.7 mg kg−1 in the surface sediment, 0.04–0.26 nM in the water column, and 48.0–77.9 mg kg−1 in suspended particles. Pb biomonitoring using blue mussels collected by the French Mussel Watch Program over the last 40 years showed a concentration decrease from 3.8 to 0.8 mg kg−1. A similar trend is observed in an estuarine sediment core. Changes in accompanying Pb isotope compositions strongly suggest a binary mixing process between Pb derived from terrigenous material and anthropogenic sources. Thus, environmental regulations restricting the release of lead into the environment contribute to a decrease in estuarine levels of this pollutant, which occurs on a decadal time scale. [Display omitted] • Lead isotopes in water and sediment show traces of older lead pollution. • Dissolved lead concentrations have decreased 100-fold down to background levels. • Environmental regulations were effective at reducing anthropogenic Pb emissions and load. [ABSTRACT FROM AUTHOR]

In this work, a multi-elemental approach combining Cu and Zn stable isotopes is used to assess the metal contamination evolution in the Loire estuary bulk sediments. Elemental geochemical data indicate an increase of metal concentrations from the beginning of the industrial period peaking in the 1990s, followed by an attenuation of metal contamination inputs to the estuary. Zinc isotope compositions suggest a binary mixing process between Zn derived from terrigenous material and multi-urban anthropogenic sources. Copper isotope systematics indicate a single natural dominant source represented by weathered silicate particles from soils and rocks. This work demonstrates the applicability of Zn isotopes to identify anthropogenic Zn sources in coastal systems, even under a low to moderate degree of contamination. Further studies are required to constrain Cu sources and to elucidate possible effects of grain-size and mineralogy in the Cu isotope composition of sediment in the Loire estuary. • Geochemical data and Cu and Zn isotopes were investigated in the Loire estuary. • Cu and Zn isotope compositions of sediments vary in spatial and temporal scales. • Zinc isotopes suggest a mixing process between terrigenous and urban sources. • Cu isotopes indicate a natural dominant source represented by weathered material. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Introduction The incorporation of selenium in the structure of nucleosides is a promising strategy to develop novel therapeutic molecules. Objective To assess the toxic effects of three AZT derivatives containing organoselenium moieties on human erythrocytes. Methodology Freshly human erythrocytes were acutely treated with AZT and selenium derivatives SZ1 (chlorophenylseleno), SZ2 (phenylseleno) and SZ3 (methylphenylseleno) at concentrations ranging from 10 to 500 μM. Afterwards, parameters related to membrane damage, redox dyshomeostasis and eryptosis were determined in the cells. Results The effects of AZT and derivatives toward erythrocytes differed considerably. Overall, the SZ3 exhibited similar effect profiles to the prototypal AZT, without causing cytotoxicity. Contrary, the derivative SZ1 induced hemolysis and increased the membrane fragility of cells. Reactive species generation, lipid peroxidation and thiol depletion were also substantially increased in cells after exposure to SZ1. δ -ALA-D and Na+/K+-ATPase activities were inhibited by derivatives SZ1 and SZ2. Additionally, both derivatives caused eryptosis, promoting cell shrinkage and translocation of phosphatidylserine at the membrane surface. The size and granularity of erythrocytes were not modified by any compound. Conclusion The insertion of either chlorophenylseleno or, in a certain way, phenylseleno moietes in the structure of AZT molecule was harmful to erythrocytes and this effect seems to involve a pro-oxidant activity. This was not true for the derivative encompassing methylphenylseleno portion, making it a promising candidate for pharmacological studies. [ABSTRACT FROM AUTHOR]

Several types of connections have been developed for precast structures, many of them with a focus on the beam-to-column connection. An important aspect of the design of these connections is to ensure the safety of the construction building during the assembly of the precast elements, which necessarily takes into account the safety of the temporary beam-to-column connection. Therefore, this paper presents a study of a beam-to-column connection for the assembly stage compound by a U profile steel corbel embedded in the column that support a cantilevered steel tube in the beam extremity, so-called Cazaly-Hanger device. The cantilevered steel tube fits in the U profile steel corbel that restricts the beam tipping. The results of the tests indicate that the proposed connection shows potential to be applied in the assembly phase of precast structures, having adequate torsion strength, against beam tipping, up to a loading equivalent of 60% of the theoretical strength of the steel corbel. The U profile steel corbel showed partial flexural yielding of the cross-section and ultimate load up to 38% higher than the value predicted by the analytical model. In addition, the results show that the steel strap used in the Cazaly Hanger device can be replaced by steel rebars welded to the profile without compromising its strength. The connection tested was computationally modelled using a finite element computational package, and a good agreement with results of the test was showed. Then, two proposals for modifying the connection by used wedding were analysed through the computational modelling. Results show that the connection strength can be increased by up to 17% due to better continuity of the corbel and cantilevered tube in the assembly stage. [ABSTRACT FROM AUTHOR]

This work presents, for the first time, the electrochemical detection of methyl(2S)-2-{[1-(5-fluoropentyl)-1H-indole-3-carbonyl]amino}-3,3-dimethyl butanoate (5F-MDMB-PICA), which is one of the most reported synthetic cannabinoids (SCs) in seized forensic samples. The 5F-MDMB-PICA detection is based on adsorptive stripping differential pulse voltammetry (AdSDPV) using a boron-doped diamond electrode (BDDE) with short anodic-cathodic pretreatment. This SC exhibited an irreversible oxidation process at around +1.2 V on a BDDE (vs. Ag|AgCl|KCl (sat.)) in 0.1 mol L−1 H 2 SO 4. The proposed method presents a wide linear range (1.0 to 100 µmol L−1) for 5-MDMB-PICA determination and a low limit of detection (0.09 µmol L−1). The selectivity for 5F-MDMB-PICA detection at the BDDE using AdSDPV was evaluated using six other SCs and no interference was observed. In addition, the BDDE showed a good stability of 5F-MDMB-PICA electrochemical responses. Addition-recovery studies in real seized samples presented results close to 100%. Therefore, the combination of BDDE with AdSDPV demonstrates a great potential for a simple and fast screening of 5F-MDMB-PICA and an on-site application in forensic analysis. [Display omitted] [ABSTRACT FROM AUTHOR]

• A 3D finite element model is developed for the two-step corbel. • A database with 126 corbels is made by parametric analysis. • An analytical model is proposed for the design of two-step corbels. • The proposed analytical model has strength reduction factors calculated. Corbels are a common element in the beam–column connections of precast concrete structures. This paper analyses the failure of a two-step corbels system using computational modeling. A finite element model is developed and calibrated using the test results for two-step corbels without secondary reinforcement but with steel fiber–reinforced concrete. A database is developed from the parametric analyses of two-step corbels, varying the a/d ratio (0.34–0.76), the rate of the main reinforcement (0.19–0.50%), the compressive strength of the concrete (30–70 MPa) and the amount of steel fibers (1.0% and 1.5%). An improved analytical model, using the developed database, is proposed to design the two-step corbels. The reliability of the proposed analytical model is evaluated using a second database, developed in this paper, and a strength reduction factor of 0.66 for failure by yielding of the main reinforcement and 0.56 for failure by crushing of the concrete strut, were obtained. Therefore, the improved analytical model obtained for the design of two-step corbels represents an advance, in terms of structural safety and economy, when compared to the previous analytical models recommended in the literature. [ABSTRACT FROM AUTHOR]

The application of zinc (Zn) isotopes in bivalve tissues to identify zinc sources in estuaries was critically assessed. We determined the zinc isotope composition of mollusks ( Crassostrea brasiliana and Perna perna ) and suspended particulate matter (SPM) in a tropical estuary (Sepetiba Bay, Brazil) historically impacted by metallurgical activities. The zinc isotope systematics of the SPM was in line with mixing of zinc derived from fluvial material and from metallurgical activities. In contrast, source mixing alone cannot account for the isotope ratios observed in the bivalves, which are significantly lighter in the contaminated metallurgical zone (δ 66 Zn JMC = +0.49 ± 0.06‰, 2σ, n = 3) compared to sampling locations outside (δ 66 Zn JMC = +0.83 ± 0.10‰, 2σ, n = 22). This observation suggests that additional factors such as speciation, bioavailability and bioaccumulation pathways (via solution or particulate matter) influence the zinc isotope composition of bivalves. [ABSTRACT FROM AUTHOR]

An old electroplating plant in Sepetiba Bay discharged metal-enriched wastes into the surrounding mangroves for 30 years (from the 1960s to 1990s), resulting in a hotspot zone of legacy sediments highly concentrated in toxic trace metals. This study applies Cu and Pb isotope systems to investigate the contributions of past punctual sources relative to emerging modern diffuse sources. The electroplating activity imprinted particular isotopic signatures (average δ65Cu SRM-976 : 0.4 ‰ and 206Pb/207Pb: 1.14) distinct from the natural baseline and urban fluvial sediments. The isotopic compositions of tidal flat sediments show intermediate isotope compositions reflecting the mixing of Cu and Pb from the hotspot zone and terrigenous materials carried by rivers. Oyster isotope fingerprints match legacy sediments, attesting that anthropogenic Cu and Pb are bioavailable to the biota. These findings confirm the interest in combining two or more metal isotope systems to discriminate between modern and past metal source emissions in coastal environments. [Display omitted] • Electroplating wastes imprint particular metal isotope ratios in legacy sediments. • Isotope analysis reveals the anthropogenic Cu and Pb dispersion across the bay. • Tidal flat isotope ratios reflect mixing of legacy and fluvial sediment particles. • Isotope fingerprints of Cu and Pb in oysters match legacy contaminated sediments. [ABSTRACT FROM AUTHOR]

Antifouling paints (APs) are one of the important sources of Cu and Zn contamination in coastal environments. This study applied for the first-time a multi-isotope (Cu, Zn, and Pb) and multi-elemental characterization of different AP brands to improve their tracking in marine environments. The Cu and Zn contents of APs were shown to be remarkably high ∼35% and ∼8%, respectively. The δ65Cu AE647 , δ66Zn IRMM3702 , and 206Pb/207Pb of the APs differed depending on the manufacturers and color (−0.16 to +0.36‰, −0.34 to +0.03‰, and 1.1158 to 1.2140, respectively). A PCA analysis indicates that APs, tires, and brake pads have also distinct elemental fingerprints. Combining isotopic and elemental ratios (e.g., Zn/Cu) allows to distinguish the environmental samples. Nevertheless, a first attempt to apply this approach in highly urbanized harbor areas demonstrates difficulties in source apportionments, because the sediment was chemically and isotopically homogeneous. The similarity of isotope ranges between the harbor and non-exhaust traffic emission sources suggests that most metals are highly affected by urban runoff, and that APs are not the main contributors of these metals. It is suspected that AP-borne contamination should be punctual rather than dispersed, because of APs low solubility properties. Nevertheless, this study shows that the common coastal anthropogenic sources display different elemental and isotopic fingerprints, hence the potential for isotope source tracking applications in marine environments. Further study cases, combined with laboratory experiments to investigate isotope fractionation during releasing the metal sources are necessary to improve non-traditional isotope applications in environmental forensics. [Display omitted] • First multi-isotopic and elemental fingerprints of antifouling paints (APs). • APs isotopic compositions vary depending on manufacturer and color. • Unique chemical fingerprint of APs differentiates them from other pollutants. • Major contribution of harbor sediments in Korea indicated urban sources than APs. • Metal isotopic signatures may enable source discrimination in forensic studies. [ABSTRACT FROM AUTHOR]

This study provides the first geographic and temporal large-scale analysis of Cu stable isotope compositions in indigenous oysters to biomonitor anthropogenic Cu inputs in aquatic systems. It includes oyster samples from French marine environments with distinct Cu-pollution levels and histories and extends over several decades of biomonitoring. Sample series composed of oysters from the same season and similar size/age intended to avoid biological biases. Oysters in macrotidal estuaries (Loire and Gironde, Western France) display fluctuating Cu concentrations without clear temporal trends, challenging to infer anthropogenic influence. Conversely, the time series of their Cu isotope ratios indicate a constant proportion of natural and anthropogenic Cu sources since the 1980s. In contrast, Cu isotope compositions in oysters from the progressively developing locales (urbanization and recreational boating) of Arcachon and Vilaine bays shift positively over time, along with increasing Cu concentrations. This finding suggests a gradual augmentation in the bioaccumulation of anthropogenic Cu over time. Thus, Cu isotope compositions in oysters is an unambiguous and robust approach to pinpoint anthropogenic Cu contamination in marine biomonitoring. Furthermore, Cu concentrations combined with isotope compositions yield site-specific fingerprints allowing geographic discrimination among oysters. This two-dimensional Cu signature is promising as a tool for seafood traceability. [Display omitted] • The first large-scale analysis of Cu stable isotope ratios in oysters is presented. • Bioaccumulation of anthropogenic Cu shift isotope ratios of oysters' soft tissues. • Isotope biomonitoring indicates temporal trends in anthropogenic Cu contamination. • Elemental and isotope Cu discriminate geographic origins of oysters. [ABSTRACT FROM AUTHOR]

This study uses Cu and Zn isotopic compositions as proxies of sources and metal transfers in the planktonic food webs from the Mediterranean Sea. Plankton was collected in spring 2019 in the deep chlorophyll maximum (DCM) along a North-South transect including coastal and offshore zones (MERITE-HIPPOCAMPE campaign). δ65Cu and δ66Zn were determined on four planktonic size fractions from 60 to 2000 μm. Combined δ65Cu and δ66Zn with geochemical tracers (Ti, particulate organic phosphorus) showed that geogenic particles were ubiquitous with plankton assemblages. The δ15N ecological tracer showed that planktonic food web was enriched in heavy isotopes of Cu and Zn in the higher trophic levels. δ65Cu were correlated with picoplankton in the offshore zone, and with zooplankton in the southern coastal zone. Firmicutes bacteria were found correlated with δ66Zn in northern and southern coastal zones suggesting decomposition of particulate matter at the DCM. These findings suggest that biogeochemical process may impact Cu and Zn isotopy in the planktonic community. • Cu and Zn transfers in the Mediterranean planktonic food web • δ65Cu and δ66Zn compositions are impacted by geogenic inputs. • δ65Cu and δ66Zn compositions correlated with planktonic community. [ABSTRACT FROM AUTHOR]

Composite beams of steel and concrete have been studied for a long time. The transfer of longitudinal shear stresses at the interface between the beam and the slab is a key point in obtaining the composite beam behaviour, which is usually achieved by means of shear connectors. In this case, the joint behaviour of the two materials depends on the strength and stiffness of the interface connector. Headed stud connectors for solid concrete slabs are the most common solution to achieve the composite behaviour. However, there is little information on shear connectors associated with precast concrete hollow-core slabs. This study aims to determine, through push-out tests, the shear strength of headed stud connectors associated with precast hollow-core slabs with a structural concrete topping. The analysed hollow-core slabs have two different heights and a minimum structural concrete topping of 40 mm. The strength of the in situ concrete infill joints and the rate of transverse reinforcement were varied in the present study. The results were compared to code prescriptions, and a proposition to modify an existing design equation for the ultimate shear capacity of headed studs in composite precast hollow-core slab beams is presented, focusing on the influence of the structural concrete topping. [ABSTRACT FROM AUTHOR]

Marine suspended particulate matter (SPM) plays a pivotal role in the marine biogeochemical cycling of trace elements. This study investigates metal distributions and copper (Cu) and zinc (Zn) stable isotope ratios in different size fractions of SPM from two sampling stations on the inner continental shelf of northern Bay of Biscay (NE Atlantic), a zone highly influenced by the macrotidal Loire estuary, the outlet of a major European river. The objective of this study is to test stable isotopes as tools to infer the origins of particles and their formation processes, and to infer relevant Cu and Zn biogenic pools involved in marine trophic transfers of these metals. SPM samples were nearly quantitatively mineralized (i.e., without HF) to determine metals and Cu and Zn isotopes in their more labile and reactive phases. Their δ65Cu SRM-976 values ranged from −0.45 to +0.51‰, with higher Cu concentrations accompanying particle size decreasing. The δ66Zn JMC-Lyon values in SPM sub-fractions varied from +0.14 to +0.76‰, and were uncorrelated to both Zn concentrations and particle size. Compared to larger size fractions, increased Al and Fe levels (proxies for terrigenous materials) and enrichments in lighter Cu and Zn isotopes observed in the smaller size SPM sub-fractions suggest that a major proportion of SPM Cu and Zn is associated with geogenic particles. Conversely, the relative enrichment of heavy isotopes in coarser particles is attributable to an increase of Cu and Zn metabolically incorporated into biogenic organic particles (e.g., plankton), and by surface adsorption onto organic detrital particles. The higher δ-values attributed to biogenic particles likely represents the isotope composition of the local marine organic matter available to primary consumers like filter-feeders (oysters). Thus, this study shows that targeting particles of specific size classes allows to identify relative dominances of biogenic and geogenic carrier phases. Identifying these pools and their isotopic composition may help to track Cu and Zn transfers through marine food-web in future studies. [Display omitted] • Cu and Zn isotopes in different particle sizes of SPM from Biscay Bay. • Four size fractions (63–250; 250–500; 500–1000; and >2000 μm) were target. • Isotopes help identify geogenic and biogenic pools in SPM sub-fractions. • Geogenic pools are enriched in the light and biogenic pools in the heavy isotopes. • Isotopes in SPM sub-fractions may help to constrain food-web metal transfers. [ABSTRACT FROM AUTHOR]