48 research outputs found

    A first attempt to evaluate the toxicity to Phaeodactylum tricornutum Bohlin exposed to rare earth elements

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    The increasing use and demand of rare earth elements in many emerging technologies is leading to a potentially higher input to the marine environment. This study compared for the first time the effect of lanthanum (La), cerium (Ce), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), and erbium (Er) to the microalga Phaeodactylum tricornutum Bohlin. The algal growth inhibition was investigated after 72 h of exposure. The median effect concentrations (EC50) ranged from 0.98 mg/L to 13.21 mg/L and elements were ranked as follows: Gd > Ce > Er > La > Eu > Nd > Dy > Sm. The comparison of predicted no effect concentrations (PNEC) for hazard and risk assessment with measured environmental concentrations showed that ecological risks deriving from REEs could be present, but limited to specific environments like estuarine waters. The results support evidence of actions to manage the REE impact in seawater environments, looking to improve the monitoring tailored to the different and dynamic nature of ecosystems

    Coastal high-frequency radars in the Mediterranean ??? Part 2: Applications in support of science priorities and societal needs

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    International audienceThe Mediterranean Sea is a prominent climate-change hot spot, with many socioeconomically vital coastal areas being the most vulnerable targets for maritime safety, diverse met-ocean hazards and marine pollution. Providing an unprecedented spatial and temporal resolution at wide coastal areas, high-frequency radars (HFRs) have been steadily gaining recognition as an effective land-based remote sensing technology for continuous monitoring of the surface circulation, increasingly waves and occasionally winds. HFR measurements have boosted the thorough scientific knowledge of coastal processes, also fostering a broad range of applications, which has promoted their integration in coastal ocean observing systems worldwide, with more than half of the European sites located in the Mediterranean coastal areas. In this work, we present a review of existing HFR data multidisciplinary science-based applications in the Mediterranean Sea, primarily focused on meeting end-user and science-driven requirements, addressing regional challenges in three main topics: (i) maritime safety, (ii) extreme hazards and (iii) environmental transport process. Additionally, the HFR observing and monitoring regional capabilities in the Mediterranean coastal areas required to underpin the underlying science and the further development of applications are also analyzed. The outcome of this assessment has allowed us to provide a set of recommendations for future improvement prospects to maximize the contribution to extending science-based HFR products into societally relevant downstream services to support blue growth in the Mediterranean coastal areas, helping to meet the UN's Decade of Ocean Science for Sustainable Development and the EU's Green Deal goals

    Coastal high-frequency radars in the Mediterranean ??? Part 1: Status of operations and a framework for future development

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    Due to the semi-enclosed nature of the Mediterranean Sea, natural disasters and anthropogenic activities impose stronger pressures on its coastal ecosystems than in any other sea of the world.With the aim of responding adequately to science priorities and societal challenges, littoral waters must be effectively monitored with high-frequency radar (HFR) systems. This land-based remote sensing technology can provide, in near-real time, fine-resolution maps of the surface circulation over broad coastal areas, along with reliable directional wave and wind information. The main goal of this work is to showcase the current status of the Mediterranean HFR network and the future roadmap for orchestrated actions. Ongoing collaborative efforts and recent progress of this regional alliance are not only described but also connected with other European initiatives and global frameworks, highlighting the advantages of this cost-effective instrument for the multi-parameter monitoring of the sea state. Coordinated endeavors between HFR operators from different multi-disciplinary institutions are mandatory to reach a mature stage at both national and regional levels, striving to do the following: (i) harmonize deployment and maintenance practices; (ii) standardize data, metadata, and quality control procedures; (iii) centralize data management, visualization, and access platforms; and (iv) develop practical applications of societal benefit that can be used for strategic planning and informed decision-making in the Mediterranean marine environment. Such fit-for-purpose applications can serve for search and rescue operations, safe vessel navigation, tracking of marine pollutants, the monitoring of extreme events, the investigation of transport processes, and the connectivity between offshore waters and coastal ecosystems. Finally, future prospects within the Mediterranean framework are discussed along with a wealth of socioeconomic, technical, and scientific challenges to be faced during the implementatio

    On the equipment design of a spinning disk reactor for the production of novel nano silver in amorphous zeolite particles

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    In recent years there is an increasing use of silver nanoparticles (AgNPs) in a wide range of products, due to enhanced antibacterial and antiviral properties. In most applications, AgNPs are used immobilized on supporting surfaces, such as a coating over a medium or embedded into polymer matrixes, sensibly reducing their active surface. To overcome this constraint, it appears to be profitable to use microporous materials as a support to AgNPs, such as zeolites. One difficulty to produce AgNPs in zeolite particles (AgNP-Z) is the impossibility to adopt standard coating procedures at nano-scale. For this reason, AgNPs were produced separately and then embedded into zeolites during the synthesis of the latter. This result was achieved by use of a spinning disk reactor (SDR) during both involved process steps. In a first step, AgNPs were produced by SDR, achieving the production of particles of modal size equal to 66 nm after proper process optimization. After this, the synthesised AgNPs suspension was then employed during the chemical zeolite synthesis over the disk surface. SEM analysis confirmed the homogeneous position of the AgNPs placed deep within the formed amorphous zeolite structure cavities to achieve chemical availability. By adopting this technique AgNP-Z globules of a mean diameter of 150 nm forming particles of about 54 mu m have been successfully produced. Finally, the experimental work assisted to extent general insight to the design and operation of a SDR for particles production, and a simplified model will here be proposed and validated

    Central odontogenic fibroma of the mandible: A case report with diagnostic considerations

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    Introduction: Odontogenic fibroma (OF), a rare odontogenic tumor of mesodermal origin, has been thought to originate from either dental follicle, periodontal ligament, or dental papilla [1]. Different studies reported high variability in the incidence rate as being between 3 and 23% of all odontogenic tumors [2,3]. OF manifests a dual character at the histopathological examination showing odontogenic epithelial structures mimicking those observed in biopsy of ameloblastoma and, in addition, peculiar fragments of cellular stroma. The clinical and radiological features of OF are similar to other odontogenic and/or non-odontogenic tumours and the differential diagnosis may first occur at fine-needle aspiration biopsy. Presentation of case: In the case reported, a young patient showed a localized gingival enlargement involving radiologically the superior margin of the right angle of the mandible and associated with an un-erupted tooth. The morphological characteristics together with clinical and radiologic findings confirmed the tumor to be a central odontogenic fibroma (COF) with secondary gingival involvement. Discussion and conclusion: Benign odontogenic tumors may be distinguished from other odontogenic/non-odontogenic neoplasias and from malignant tumours through a cytologic differential diagnosis as treatment differs accordingly

    Insights into the Ecotoxicology of Radicinin and (10<i>S</i>,11<i>S</i>)-(—)-<i>epi</i>-Pyriculol, Fungal Metabolites with Potential Application for Buffelgrass (<i>Cenchrus ciliaris</i>) Biocontrol

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    Buffelgrass (Cenchrus ciliaris L.) is an invasive C4 perennial grass species that substantially reduces native plant diversity of the Sonoran Desert through fire promotion and resource competition. Broad-spectrum herbicides are essentially used for its control, but they have a negative environmental and ecological impact. Recently, phytotoxicity on C. ciliaris has been discovered for two metabolites produced in vitro by the phytopathogenic fungi Cochliobolus australiensis and Pyricularia grisea. They were identified as (10S,11S)-(—)-epi-pyriculol and radicinin and resulted in being potential candidates for the development of bioherbicides for buffelgrass biocontrol. They have already shown promising results, but their ecotoxicological profiles and degradability have been poorly investigated. In this study, ecotoxicological tests against representative organisms from aquatic ecosystems (Aliivibrio fischeri bacterium, Raphidocelis subcapitata alga, and Daphnia magna crustacean) revealed relatively low toxicity for these compounds, supporting further studies for their practical application. The stability of these metabolites in International Organization for Standardization (ISO) 8692:2012 culture medium under different temperatures and light conditions was also evaluated, revealing that 98.90% of radicinin degraded after 3 days in sunlight. Significant degradation percentages (59.51–73.82%) were also obtained at room temperature, 30 °C or under ultraviolet (254 nm) light exposure. On the other hand, (10S,11S)-epi-pyriculol showed more stability under all the aforementioned conditions (49.26–65.32%). The sunlight treatment was also shown to be most effective for the degradation of this metabolite. These results suggest that radicinin could provide rapid degradability when used in agrochemical formulations, whereas (10S,11S)-epi-pyriculol stands as a notably more stable compound

    Synthesis of platinum (II) complexes of thymidine (Thy) and 1-methylthymine (MeThy); crystal structure of cis-[PtCl(PPh3)2(3-MeThy)]

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    The reaction of 39,59-di-O-acetylthymidine with [Pt(PPh3)4] and KCl yielded a platinum(II) complex where the platinum is co-ordinated to the nucleobase through the N3 atom. In a similar reaction 1-methylthymine (1-MeThy) furnished the complex cis-[PtCl(1-MeThy)(PPh3)2], whose structure was determined by spectroscopic data and single crystal X-ray diffraction. When 1-MeThy was treated with [Pt(PPh3)4] in the absence of chloride ions the complex trans-[Pt(OH)(1-MeThy)(PPh3)2] was obtained

    Amoxicillin in Water: Insights into Relative Reactivity, Byproduct Formation, and Toxicological Interactions during Chlorination

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    In recent years, many studies have highlighted the consistent finding of amoxicillin in waters destined for wastewater treatment plants, in addition to superficial waters of rivers and lakes in both Europe and North America. In this paper, the amoxicillin degradation pathway was investigated by simulating the chlorination process normally used in a wastewater treatment plant to reduce similar emerging pollutants at three different pH values. The structures of 16 isolated degradation byproducts (DPs), one of which was isolated for the first time, were separated on a C-18 column via a gradient HPLC method. Combining mass spectrometry and nuclear magnetic resonance, we then compared commercial standards and justified a proposed formation mechanism beginning from the parent drug. Microbial growth inhibition bioassays with Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were performed to determine the potential loss of antibacterial activity in isolated degradation byproducts. An increase of antibacterial activity in the DPs was observed compared to the parent compound

    Amoxicillin in Water: Insights into Relative Reactivity, Byproduct Formation, and Toxicological Interactions during Chlorination

    No full text
    In recent years, many studies have highlighted the consistent finding of amoxicillin in waters destined for wastewater treatment plants, in addition to superficial waters of rivers and lakes in both Europe and North America. In this paper, the amoxicillin degradation pathway was investigated by simulating the chlorination process normally used in a wastewater treatment plant to reduce similar emerging pollutants at three different pH values. The structures of 16 isolated degradation byproducts (DPs), one of which was isolated for the first time, were separated on a C-18 column via a gradient HPLC method. Combining mass spectrometry and nuclear magnetic resonance, we then compared commercial standards and justified a proposed formation mechanism beginning from the parent drug. Microbial growth inhibition bioassays with Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were performed to determine the potential loss of antibacterial activity in isolated degradation byproducts. An increase of antibacterial activity in the DPs was observed compared to the parent compound
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