156 research outputs found

    Characterization, Classification And Analysis Of The Main Properties Of The Southwestern Goias Soil

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    Characterization of the soil and the grouping of its properties through main component analysis can assist in the classification and observation of the consequences of the conversion of native forest areas in pastures. Such data can aid in management practices. Considering the lack of studies in Cerrado soils of south-western Goias, developed metagranites of Jurubatuba suite, the objective was to classify and study the physical, chemical and mineralogical soil (under native forest and pasture) Southwest of Goias. Soil sampling and classification followed the Field Methods Manual and the Brazilian System of Soil Classification, respectively. The physical, chemical and mineralogical soil were studied, as well as main component analysis made for these attributes. The profile 1 under native forest was classified as "Cambissolo Háplico Tb eutrófico latossólico". The profile 2 under degraded pasture was rated "Latossolo Amarelo eutrófico típico". In addition, the profile 3 under rotated pasture was rated as "Latossolo Vermelho eutrófico chernossólico". It was observed that the "Latossolos" have higher bulk density and soil penetration resistance, indicating greater soil compaction. They showed high amounts of iron oxides and minor amount of nutrients such as calcium and magnesium. The principal component analysis allowed the grouping of profiles into two groups. Group 1 brought together the properties related to "Latossolos", and the second was related to "Cambissolo" properties. Thus, the principal components analysis aids the understanding of soil properties and the grouping of soils with similar characteristics, the level of order and management.3731135115

    Passive direct methanol fuel cells acting as fully autonomous electrochemical biosensors: Application to sarcosine detection

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    This work describes an innovative electrochemical biosensor that advances its autonomy toward an equipment-free design. The biosensor is powered by a passive direct methanol fuel cell (DMFC) and signals the response via an electrochromic display. Briefly, the anode side of the DMFC power source was modified with a biosensor layer developed using molecularly imprinted polymer (MIP) technology to detect sarcosine (an amino acid derivative that is a potential cancer biomarker). The biosensor layer was anchored on the surface of the anode carbon electrode (carbon black with Pt/Ru, 40:20). This was done by bulk radical polymerization with acrylamide, bis-acrylamide, and vinyl phosphonic acid. This layer selectively interacted with sarcosine when integrated into the passive DMFC (single or multiple, in a stack of 4), which acted as a transducer element in a concentration-dependent process. Serial assembly of a stack of hybrid DMFC/biosensor devices triggered an external electrochromic cell (EC) that produced a colour change. Calibrations showed a concentration-dependent sarcosine response from 3.2 to 2000 µM, which is compatible with the concentration of sarcosine in the blood of prostate cancer patients. The final DMFC/biosensor-EC platform showed a colour change perceptible to the naked eye in the presence of increasing sarcosine concentrations. This colour change was controlled by the DMFC operation, making this approach a self-controlled and self-signalling device. Overall, this approach is a proof-of-concept for a fully autonomous biosensor powered by a chemical fuel. This simple and low-cost approach offers the potential to be deployed anywhere and is particularly suitable for point-of-care (POC) analysis.The authors acknowledge the financial support of EU-Horizon 2020 (Symbiotic, FET-Open, GA665046), and from national funds from FCT - Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, UIDB/50025/2020 and UID/EMS/00532/2019. Nádia Ferreira (SFRH/BD/122955/2016), Liliana Carneiro (SFRH/BD/122954/2016), and Ana Carolina Marques (SFRH/BD/115173/2016) acknowledge Fundação para a Ciência e Tecnologia (FCT) for financial support.info:eu-repo/semantics/publishedVersio

    Diversity and patterns of marine non‐native species in the archipelagos of Macaronesia

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    Aims The present study is the first attempt to grasp the scale and richness of marine biological invasions in Macaronesia. We pioneered a comprehensive non-native species (NNS), inventory in the region to determine their diversity patterns and native distribution origins. NNS were defined here as the result of both introductions and range expansions. We also used statistical modelling to examine relationships among NNS richness, anthropogenic activities, demographic and geographical variables across Macaronesia. Location Macaronesia. Methods A comprehensive literature search was conducted for marine NNS records in Macaronesia, registering the first record's location and year from 1884 to 2020. We used univariate and multivariate analyses to evaluate differences and similarities in community composition. By applying a Generalized Linear Model (GLM), we tested hypotheses regarding NNS richness as a function of anthropogenic activities, demographic and geographical variables. Results A total of 144 marine non-native species (NNS) were recorded for the whole of Macaronesia. The highest NNS richness was registered in the Canary Islands (76 NNS), followed by the Azores (66 NNS), Madeira (59 NNS) and finally Cabo Verde (18 NNS). Some differences amongst archipelagos were observed, such as the high number of non-native macroalgae in the Azores, fishes in the Canary Islands and tunicates in Cabo Verde. Overall, macroalgae, tunicates and bryozoans were the predominant taxonomic groups in the Macaronesian archipelagos. Madeira and Canary Islands were the archipelagos with more similarity in marine NNS, and Cabo Verde the most divergent. Finally, GLM suggested that non-native richness patterns across Macaronesia were dependent on the considered archipelago and strongly affected by (1) minimum distance to the mainland, (2) the total number of ports and marinas and (3) total marinas area (km2). Conclusions The model results and NNS listing in the present study will likely raise the awareness and response regarding marine NNS in the whole Macaronesia region, serving as a baseline for future research as well as implementing and enforcing regulations related to the introduction of marine NNS in oceanic islands

    Libxc: a library of exchange and correlation functionals for density functional theory

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    The central quantity of density functional theory is the so-called exchange-correlation functional. This quantity encompasses all non-trivial many-body effects of the ground-state and has to be approximated in any practical application of the theory. For the past 50 years, hundreds of such approximations have appeared, with many successfully persisting in the electronic structure community and literature. Here, we present a library that contains routines to evaluate many of these functionals (around 180) and their derivatives.Comment: 15 page

    Nanocellulose toxicity in vitro models: contributing to its safety assessment to human health

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    As nanoceluloses são nanomateriais inovadores com potencial para uma vasta gama de aplicações industriais e biomédicas. No entanto, a expansão da sua produção tem vindo a suscitar preocupações quanto aos possíveis efeitos, a longo prazo, na saúde humana. Este estudo teve como objetivo avaliar a segurança de algumas nanoceluloses produzidas a partir de matéria-prima nacional, através da caracterização da sua potencial toxicidade em células de mamífero. Para tal, testaram-se duas celuloses nano /microfibrilares (CNF e CMF ) e uma celulose nanocristalina (CNC). Analisou-se a citotoxicidade usando ensaios colorimétricos e o ensaio clonogénico, e a genotoxicidade pelo ensaio do micronúcleo in vitro em células pulmonares de mamífero (A549 e V79 ) e em osteoblastos humanos ( MG-63 ). A indução de espécies reativas de oxigénio (ROS) e a internalização celular foram também estudadas nas células A549. Observou- -se citotoxicidade no ensaio clonogénico, principalmente no caso da CNC, mas não nos restantes ensaios, não havendo também indução de ROS. Todas as nanoceluloses revelaram efeitos genotóxicos nalgumas concentrações, uma vez que induziram micronúcleos e /ou pontes nucleoplásmicas num dos modelos celulares. Para além disso, visualizou-se a internalização da CNF e CMF, mas não da CNC, em células A549. Esta primeira avaliação toxicológica veio contribuir para prevenir a exposição a materiais celulósicos potencialmente perigosos, procurando impulsionar o desenvolvimento de materiais inovadores e mais seguros.Nanocelluloses are innovative nanomaterials with potential for a wide range of industrial and biomedical applications. However, the expansion of its production has raised concerns about their possible long-term effects on human health. This study aimed to evaluate the safety of various nanocelluloses through the characterization of their potential toxicity in mammalian cells. Two samples of nano/microfibrillar celluloses with different pre-treatments (CNF and CMF) and a nanocrystalline cellulose (CNC) were tested. The cytotoxicity of the nanocelluloses was analyzed using colorimetric assays and the clonogenic assay, and genotoxicity by the in vitro micronucleus assay in human alveolar epithelial cells (A549), human osteoblasts (MG-63) and Chinese hamster fibroblasts (V79). Induction of reactive oxygen species (ROS) and cellular internalization were also studied in A549 cells. Cytotoxicity was observed through the clonogenic assay, mainly in the case of CNC, but not in the remaining assays, with no induction of ROS. All nanocelluloses, at some of the concentrations tested, induced micronuclei and/or nucleoplasmic bridges in one of the cellular models. Furthermore, the internalization of CNF and CMF, but not of CNC was visualized in A549 cells. These results aim to contribute to preventing exposure to potentially hazardous cellulosic materials, seeking to boost the development of innovative and safer materials.Projeto ToxApp4NanoCELFI – Uma abordagem de toxicologia preditiva para a caracterização dos potenciais efeitos respiratórios de fibras de nanocelulose funcionalizadas num sistema de co-cultura (PTDC/SAU-PUB/32587/2017).info:eu-repo/semantics/publishedVersio

    Randomized controlled field trial to assess the immunogenicity and safety of rift valley fever clone 13 vaccine in livestock

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    BACKGROUND:Although livestock vaccination is effective in preventing Rift Valley fever (RVF) epidemics, there are concerns about safety and effectiveness of the only commercially available RVF Smithburn vaccine. We conducted a randomized controlled field trial to evaluate the immunogenicity and safety of the new RVF Clone 13 vaccine, recently registered in South Africa. METHODS:In a blinded randomized controlled field trial, 404 animals (85 cattle, 168 sheep, and 151 goats) in three farms in Kenya were divided into three groups. Group A included males and non-pregnant females that were randomized and assigned to two groups; one vaccinated with RVF Clone 13 and the other given placebo. Groups B included animals in 1st half of pregnancy, and group C animals in 2nd half of pregnancy, which were also randomized and either vaccinated and given placebo. Animals were monitored for one year and virus antibodies titers assessed on days 14, 28, 56, 183 and 365. RESULTS:In vaccinated goats (N = 72), 72% developed anti-RVF virus IgM antibodies and 97% neutralizing IgG antibodies. In vaccinated sheep (N = 77), 84% developed IgM and 91% neutralizing IgG antibodies. Vaccinated cattle (N = 42) did not develop IgM antibodies but 67% developed neutralizing IgG antibodies. At day 14 post-vaccination, the odds of being seropositive for IgG in the vaccine group was 3.6 (95% CI, 1.5 - 9.2) in cattle, 90.0 (95% CI, 25.1 - 579.2) in goats, and 40.0 (95% CI, 16.5 - 110.5) in sheep. Abortion was observed in one vaccinated goat but histopathologic analysis did not indicate RVF virus infection. There was no evidence of teratogenicity in vaccinated or placebo animals. CONCLUSIONS:The results suggest RVF Clone 13 vaccine is safe to use and has high (>90%) immunogenicity in sheep and goats but moderate (> 65%) immunogenicity in cattle

    Transpiration and leaf growth of potato clones in response to soil water deficit

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    Potato (Solanum tuberosum ssp. Tuberosum) crop is particularly susceptible to water deficit because of its small and shallow root system. The fraction of transpirable soil water (FTSW) approach has been widely used in the evaluation of plant responses to water deficit in different crops. The FTSW 34 threshold (when stomatal closure starts) is a trait of particular interest because it is an indicator of tolerance to water deficit. The FTSW threshold for decline in transpiration and leaf growth was evaluated in a drying soil to identify potato clones tolerant to water deficit. Two greenhouse experiments were carried out in pots, with three advanced clones and the cultivar Asterix. The FTSW, transpiration and leaf growth were measured on a daily basis, during the period of soil drying. FTSW was an efficient method to separate potato clones with regard to their response to water deficit. The advancedclones SMINIA 02106-11 and SMINIA 00017-6 are more tolerant to soil water deficit than the cultivar Asterix, and the clone SMINIA 793101-3 is more tolerant only under high solar radiation
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