323 research outputs found

    Controls on grain-size distribution in an ancient sand sea

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    The authors would like to thank Subhasish Dey for editing, Claiton Scherer and an anonymous reviewer for their constructive reviews. We thank Bernardo Peixoto for reviewing the manuscript and palaeocoordinate conversion code debug. We thank several colleagues from the all over the world that joined us during field-trips in Brazil, Uruguay and Namibia.Peer reviewedPublisher PD

    Companion animals-An overlooked and misdiagnosed reservoir of carbapenem resistance

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    Research Areas: Infectious Diseases ; Pharmacology & PharmacyABSTRACT - The dissemination of antimicrobial-resistance is a major global threat affecting both human and animal health. Carbapenems are human use β-lactams of last resort; thus. the dissemination of carbapenemase-producing (CP) bacteria creates severe limitations for the treatment of multidrugresistant bacteria in hospitalized patients. Even though carbapenems are not routinely used in veterinary medicine, reports of infection or colonization by carbapenemase-producing Enterobacterales in companion animals are being reported. NDM-5 and OXA-48-like carbapenemases are among the most frequently reported in companion animals. Like in humans, Escherichia coli and Klebsiella pneumoniae are the most represented CP Enterobacterales found in companion animals, alongside with Acinetobacter baumannii. Considering that the detection of carbapenemase-producing Enterobacterales presents several difficulties, misdiagnosis of CP bacteria in companion animals may lead to important animal and public-health consequences. It is of the upmost importance to ensure an adequate monitoring and detection of CP bacteria in veterinary microbiology in order to safeguard animal health and minimise its dissemination to humans and the environment. This review encompasses an overview of the carbapenemase detection methods currently available, aiming to guide veterinary microbiologists on the best practices to improve its detection for clinical or research purposes.info:eu-repo/semantics/publishedVersio

    Synthesis of Bi2O3/TiO2 nanostructured films for photocatalytic applications

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    Dendritic growth of bismuth oxide nanostructured films was accomplished by reactive magnetron sputtering. The deposition of the Bi2O3 template layers was adapted to abide a vapour-liquid-solid mechanism in order to develop a 3D growth morphology with high surface area templates for photocatalytic applications. TiO2 photocatalytic thin films were deposited at a later stage onto Bi2O3 layers. The obtained heterostructured films were characterized by scanning electron microscopy, X-ray diffraction and atomic force microscopy. Additionally, the photocatalytic efficiency was assessed by conducting an assay using methylene blue dye as testing pollutant under a UV-A illumination. The photocatalytic tests revealed that the Bi2O3 layers functionalized with TiO2 thin films are more efficient at degrading the pollutant, by a factor of 6, when compared with the individual layered films.The authors acknowledge the funding from the Portuguese institution Fundacao para a Ciencia e Tecnologia, through the Strategic project reference UID/FIS/04650/2013, Ph.D grant SFRH/BD/111720/2015 for Filipe C. Correia and Ph.D grant SFRH/BD/112868/2015 Juliana Marques

    Microencapsulation of essential oils: a review

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    Essential oils (EOs) are complex mixtures of volatile compounds extracted from different parts of plants by different methods. There is a large diversity of these natural substances with varying properties that lead to their common use in several areas. The agrochemical, pharmaceutical, medical, food, and textile industry, as well as cosmetic and hygiene applications are some of the areas where EOs are widely included. To overcome the limitation of EOs being highly volatile and reactive, microencapsulation has become one of the preferred methods to retain and control these compounds. This review explores the techniques for extracting essential oils from aromatic plant matter. Microencapsulation strategies and the available technologies are also reviewed, along with an in-depth overview of the current research and application of microencapsulated EOs.roject ReleaseME-POCI-01-0247-FEDER-033268, for their research grants from the Agência Nacional de Inovação, co-funded by the European Regional Development Fund (ERDF), through the Operational Programme for Competitiveness and Internationalisation (COMPETE 2020), under the PORTUGAL 2020 Partnership Agreement. Juliana F. Marques and Marta A. Forte are grateful to the Fundação para a Ciência e Tecnologia (FCT) of Portugal for their Ph.D. grants, SFRH/BD/112868/2015 and PD/BD/128491/2017, respectively. The authors also acknowledge the funding from FCT/PIDDAC through the Strategic Funds project reference UIDB/04650/2020-2023. This research was funded by the project Repel+: New solutions for mosquito repellence as an application for malaria control (project number 47036) from the Agência Nacional de Inovação, co-funded by the European Regional Development Fund (ERDF), through the Operational Programme for Competitiveness and Internationalisation (COMPETE 2020), under the PORTUGAL 2020 Partnership Agreement

    Effects of Green Tea Marinade in the Bioaccessibility of Tonalide and Benzophenone 3 in Cooked European Seabass

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    The authors acknowledgment Fundação para a Ciência e Tecnologia: NORTE-01-0145-FEDER-000041; IM acknowledges FCT for Ph.D. Grant DFA/BD/4413/2020. Publisher Copyright: © 2022 by the authors.Fish consumption is an indicator of human exposure to personal care products (PCP) such as tonalide (AHTN) and benzophenone 3 (BP3). Although most fish consumed is cooked, the impact of cooking procedures on PCP levels is difficult to evaluate. Hence, the aim of this work was to provide thorough information on the stability and bioaccessibility of AHTN and BP3 upon cooking and in vitro digestion. A green tea (Camellia sinensis) marinade, rich in polyphenol, was used as mitigating strategy to reduce these contaminants. Roasting and frying reduced AHTN and BP3 levels in European seabass (Dicentrarchus labrax) spiked samples. Additionally, the green tea marinade promoted a reduction of up to 47% AHTN and 35% BP3. Bioaccessibility of AHTN was higher (up to 45%), and increased with the use of green tea marinades. BP3 showed a bioaccessibility below 19% in all cooked samples. Overall, a decrease in PCP levels was observed after cooking; this decrease was even more pronounced when marination was previously used. However, this decrease is cancelled out by the fact that the bioaccessible fraction of the contaminants increases in an inverse way; therefore, none of these processes can be considered a mitigating alternative.publishersversionpublishe

    Human and companion animal proteus mirabilis sharing

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    Research Areas: MicrobiologyProteus mirabilis is an important pathogen that is associated with urinary tract infections. This study aims to determine the colonization and sharing of P. mirabilis between healthy companion animals and humans that are living together and to evaluate the clonal relatedness of the fecal and clinical stains. Eighteen households (24 humans, 18 dogs, 8 cats) with at least one human–animal pair were studied. Fecal samples were plated onto MacConkey and Hektoen agar and P. mirabilis PFGE analysis (NotI; Dice/UPGMA; 1.5% tolerance) was conducted for the households with multiple positive participants. Antimicrobial-resistance was tested according to CLSI. The fecal P. mirabilis pulse-types were compared with uropathogenic clinical strains (n = 183). Forty-nine P. mirabilis were isolated from eight households. The percentage of colonization in the dogs (44.4%, n = 8/18) was significantly higher (p = 0.0329) than in the humans (12.5%, n = 3/24). Three households had multiple colonized participants. One human–dog pair shared related P. mirabilis strains, which clustered with a clinical strain of animal origin (82.5%). One fecal P. mirabilis strain, from a dog, clustered with two human community-acquired clinical strains (80.9%, 88.9%). To our knowledge, this is the first report of dogs and humans living in close contact and sharing related P. mirabilis strains. The high frequency of colonization in the dogs underlines their possible role as P. mirabilis reservoirs for humans and other dogs.info:eu-repo/semantics/publishedVersio

    Caracterização e geocronologia SHRIMP U-Pb em zircão das rochas subvulcânicas do sistema pórfiro Yarumalito, Distrito de Marmato, Colômbia

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    The mining District of Marmato, located in the Central Cordillera, is considered one of the oldest gold districts in Colombia and its exploration dates back to the Inca’s times, being exploited regularly for more than a thousand years. Inserted in this context lies the Yarumalito porphyry system (YPS), characterized to concentrate ore in structure related veins and stockworks. The YPS is related to the Miocene magmatism of the Combia Formation. In this paper, the subvolcanic rocks directly associated with the mineralized zones were described in order to obtain U-Pb ages in zircon to the intrusions. Selected samples from two fertile intrusions, one andesitic (more abundant in the area) and other dioritic (more restricted), were carefully described and dated by SHRIMP. The results points to a very restricted interval for the ages, with weighted average 206Pb/238U varying from 7,00 ± 0,15 Ma for the andesitic porphyry and 6.95 ± 0.16 Ma for the dioritic porphyry. These results constrain the Yarumalito system to the final stages of the Combia magmatism and suggest a brief period for the crystallization of the mineralized subvolcanic rocks in the area and in the Marmato District.O Distrito Mineiro de Marmato, localizado na Cordilheira Central Andina, é considerado um dos mais antigos da Colômbia e as atividades de extração de ouro remontam à época dos Incas, tendo sido explorado de forma intermitente há mais de mil anos. Inserido neste contexto encontra-se o sistema pórfiro Yarumalito (SPY), caracterizado por concentrar minério em veios controlados por estruturas e stockworks. O sistema ígneo é relacionado ao magmatismo mioceno da Formação Combia. Neste trabalho foram descritas as rochas subvulcânicas diretamente relacionadas às zonas mineralizadas do SPY com o objetivo de caracterizar as intrusões e realizar datação através do método U-Pb em zircão. Amostras selecionadas de duas intrusões férteis, uma andesítica (mais abundante na área) e outra diorítica (de ocorrência mais restrita) com características intrusivas na primeira, foram criteriosamente descritas e datadas por SHRIMP na Universidade de São Paulo. Os resultados apontaram para um intervalo bastante restrito para as idades 206Pb/238U, com médias ponderadas variando de 7,00 ± 0,15 Ma para o andesito pórfiro a 6,95 ± 0,16 Ma para o diorito pórfiro. Estes resultados posicionam o sistema Yarumalito nas fases finais do magmatismo Combia e sugerem um intervalo de tempo restrito para a cristalização das intrusivas portadoras de mineralizações no Yarumalito e do Distrito de Marmato

    Preparation of robust polyamide microcapsules by interfacial polycondensation of p-phenylenediamine and sebacoyl chloride and plasticization with oleic acid

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    Microcapsules produced by interfacial polycondensation of p-phenylenediamine (PPD) and sebacoyl chloride (SC) were studied. The products were characterized in terms of morphology, mean diameter and effectiveness of dodecane encapsulation. The use of Tween 20 as dispersion stabilizer, in comparison with polyvinyl alcohol (PVA), reduced considerably the mean diameter of the microcapsules and originated smoother wall surfaces. When compared to ethylenediamine (EDA), microcapsules produced with PPD monomer were more rigid and brittle, prone to fracture during processing and ineffective retention of the core liquid. The use of diethylenetriamine (DETA) cross-linker in combination with PPD did not decrease capsule fragility. On the other hand, addition of a small fraction of oleic acid to the organic phase remarkably improved wall toughness and lead to successful encapsulation of the core-oil. Oleic acid is believed to act as a plasticizer. Its incorporation in the polymeric wall was demonstrated by FTIR and (1)H-NMR.This work was funded by FEDER funds through the Operational Programme for Competitiveness Factors (COMPETE), ON.2 – O Novo Norte – North Portugal Regional Operational Programme and National Funds through Foundation for Science and Technology (FCT) under the projects: PEst-C/EQB/UI0511, NORTE-07-0124-FEDER-000026 – RL1_ Energy and PTDC/CTM-NAN/119979/2010. The Bruker Avance III 400 spectrometer is part of the National NMR network and was purchased under the framework of the National Programme for Scientific Reequipment, REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and (FCT). Joana R. Góis acknowledges FCT-MCTES for her PhD scholarship (SFRH/BD/69635/2010)

    Release of volatile compounds from polymeric microcapsules mediated by photocatalytic nanoparticles

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    In this study we propose a suitable method for the solar-activated controlled release of volatile compounds from polymeric microcapsules bonded with photocatalytic nanoparticles. These reservoirs can find applications, for example, in the controlled release of insecticides, repellents, or fragrances, amongst other substances. The surfaces of the microcapsules have been functionalized with TiO2 nanoparticles.Upon ultraviolet irradiation, redox mechanisms are initiated on the semiconductor surface resulting in the dissociation of the polymer chains of the capsule wall and, finally, volatilization of the encapsulated compounds. The quantification of the output release has been performed by gas chromatography analysis coupled with mass spectroscopy.Strategic Project PEST-C/FIS/UI607/2011 and PTDC/CTMNAN/119979/2010 Projec

    Total facial selectivity in 2π+4π reactions of (2R,4S,5R)-4-((E)-((4-Methoxyphenyl)imino)methyl)-2-phenyl-1,3-dioxan-5-ol to electron-rich dienophiles

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    Tetrahydroquinoline (THQ) is an important structural unit present in various natural products and pharmaceutical agents having a large range of biological activities. Many approaches have been developed for the construction of THQ scaffold. Among these, the inverse electron demand hetero-Diels-Alder reaction1 or its ionic version2 is regarded as a powerful tool. The imine 3 is generated in situ from D-erythrose and p-methoxy-aniline. When the reaction is finished dienophiles were added at – 78 ºC giving products in moderate to high yields, with formation of a single diastereoisomer. In this work BF3·Et2O3 used as catalyst is supposed to help to induce facial selectivity in 2π+4π reactions. The boron atom is able to form a bridge between the oxygen and nitrogen atoms, neighbor in space. In this way rotation around bound a would be avoided, and the structure would obtain some rigidity. According to X-ray crystallography of product 4a, dienophiles approach the imine by the re face. It is likely that the packing of the dienophile hydrogens with diene’s H-4 explains the si face impediment. Reactions of the imine with vinyl ether and (E)-5-bromopenta-1,3-diene occurred in the absence of catalyst, but a single product was also formed. This was rationalized by an intramolecular hydrogen bond between the alcohol and the nitrogen atom that would confer to the structure the same rotational restriction. When 2,3-dimethylbutadiene was used as dienophile a mixture of inverse and normal polarity 2π+4π reaction product occurred in a 1:2 ratio.The FCT for financial support PTDC/EQF-MED/1671/2012, the national network of NMR (PTNMR, Bruker Avance III 400-Univ. Minho) and FEDER-COMPETE-QREN-EU funding the Department Chemistry-UM.info:eu-repo/semantics/publishedVersio
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