142 research outputs found

    Searches for axion-like particles via γγ\gamma \gamma fusion at future e+e\mathrm{e}^+\mathrm{e}^- colliders

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    Opportunities for searches for axion-like particles (ALPs) coupling to photons in e+e\mathrm{e}^+\mathrm{e}^- collisions at the Future Circular Collider (FCC-ee) and International Linear Collider (ILC) are investigated. We perform a study of the photon-fusion production of ALPs decaying into two photons, e+eγγe+  a(γγ)  e\mathrm{e}^+\mathrm{e}^- \overset{\gamma \gamma}{\longrightarrow} \mathrm{e}^{+}\;a(\gamma \gamma)\;\mathrm{e}^{-}, over the light-by-light continuum background, for the planned FCC-ee and ILC center-of-mass energies and integrated luminosities. An analysis of the feasibility measurements is presented using parametrized simulations for two types of detectors. Upper limits at 95% confidence level (CL) on the cross section for ALP production, σ(γγaγγ)\sigma(\gamma \gamma \to a \to \gamma \gamma), and on the ALP-photon coupling are obtained over the ma0.1m_a \approx 0.1--1000 GeV ALP mass range, and compared to current and future collider searches. Production cross sections down to σ(γγaγγ)1\sigma(\gamma \gamma \to a \to \gamma \gamma) \approx 1 fb (1 ab) will be probed at ma1m_a\approx 1 (300) GeV, corresponding to constraints on the axion-photon coupling as low as gaγγ2103g_\mathrm{a\gamma \gamma} \approx 2\cdot10^{-3} TeV1^{-1}

    Levantamentos geofísicos no setor português da Faixa Piritosa Ibérica: perspetiva global da sua importância em prospeção de sulfuretos maciços e interpretação geológica

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    ABSTRACT: The application of geophysical techniques to massive sulphide deposits exploration has proven to be a success in the Iberian Pyrite Belt (IPB) metallogenetic province, both in Portugal and in Spain. Several hidden deposits were discovered through the interpretation of geological models, supported by geophysical data collected in land and airborne surveys, as well as applied using down hole techniques in selected drill holes. This paper presents an overview of the methodologies applied in Portugal in the South Portuguese Zone (SPZ) geological domain, where the IPB is included, mostly by the LNEG and mining companies, with emphasis on the interpretation of the regional gravity, magnetometry and radiometry surveys, published in 1/400 000 scale by the EXPLORA/Alentejo2020 Project. In this regional mapping program, the large volume of data collected by LNEG and mining companies since the 1960’s was compiled and processed. The integrated interpretation and correlation between these methods will enable a better planning of new IPB exploration investments. IPB Volcano-Sedimentary Complex (VSC, Famennian to Late Visean age) lineaments are well defined in the gravity and magnetic fields along the IPB western region (e.g. Alcoutim/Neves Corvo/Montinho/Sesmarias/Lousal/Caveira). Aeromagnetic data also reflect deep and large anomalies related with the SPZ basement. A rock density database is presented and used to interpret the gravity data. Radiometric map (Natural Radioactivity), based mostly in airborne radiometric surveys, show contrasts between rocks in Paleozoic, Mesozoic and Cenozoic formations and correlations with geological and hydrothermal mapping are highlighted. The use of geophysical techniques is particularly critical in areas where VSC is concealed by younger sediments (e.g. Baixo Alentejo Flysch Group and/or Cenozoic formations), allowing the selection of target areas. Case studies are discussed based on electromagnetic, seismic and magnetotelluric methods and on the high mineral potential of defined targets. Multilayered data correlation (geophysics including petrophysical data, geochemistry and stratigraphic high-resolution models) is a key prospecting methodology and is essential for the accurate modelling of ore horizons and geological structures. Considering the IPB potential for VMS deposits, including the possible discovery of new giant (> 200 Mt) deposits, an increase of investment in new geophysical methods can be predicted. LNEG development of R&D projects such as EXPLORA/Alentejo2020 and SmartExplorationTM/H2020 also contribute to a favourable setting in the province, both in near mining and green fields scenarios. Thus, new discoveries are expected, like others made in the recent times in the IPB Portuguese sector, such as Lagoa Salgada (SFM, 1992, SFM; Redcorp/EDM, 2011; Redcorp/Ascendant/EDM, 2017), Semblana (Somincor-AGC-Lundin Mining, 2010), Monte Branco (Somincor Lundin Mining, 2012) and Sesmarias (Maepa/Avrupa, 2014). The importance of these data goes beyond the mineral exploration purpose. Since some of them use rock and mineral physical properties that can be related with environmental contamination (e.g. radiometry and magnetics) they can also be used in geochemical background studies, acid mine drainage and metal dispersion. Therefore, they can also promote a deeper knowledge in other areas of research related with environment preservation.RESUMO: A aplicação de técnicas de prospeção geofísica na pesquisa de jazigos de sulfuretos maciços na Faixa Piritosa Ibérica (FPI) tem-se revelado um sucesso em Portugal e em Espanha. Vários jazigos ocultos foram descobertos a partir da interpretação de modelos geológicos, com o apoio de dados geofísicos recolhidos em levantamentos terrestres, aerotransportados ou em profundidade, em sondagens (diagrafias). Neste artigo, apresenta-se uma análise das metodologias aplicadas principalmente pelo LNEG e empresas mineiras em Portugal, na Zona Sul Portuguesa (ZSP), onde se insere a FPI. Destaca-se a interpretação dos levantamentos regionais, esc. 1/400 000, de gravimetria, magnetometria e radiometria (EXPLORA/Alentejo2020). Nestes programas, foi feito o processamento de um volume de informação significativo, a partir de dados obtidos desde a década de 1960. Neste contexto indicam-se diversos alinhamentos de gravimetria e de aeromagnetometria relativos a unidades geológicas com elevado potencial mineiro, como o Complexo Vulcano-Sedimentar (CVS, idade Famenniano a Viseano sup.), sobressaindo o eixo Alcoutim/Neves Corvo/Montinho/Sesmarias/Lousal/Caveira. Os dados de aeromagnetismo refletem também anomalias com origens mais profundas e relacionadas com a estrutura basal da ZSP. A base de dados de densidades de rocha é utilizada na interpretação gravimétrica da FPI. O mapa radiométrico (Radioatividade Natural), baseado fundamentalmente em radiometria aeroportada (contagens totais) mostra o contraste à superfície de litologias das formações paleozoicas, mesozoicas e cenozoicas, sendo salientado, no primeiro caso, a sua correlação com a cartografia de alterações hidrotermais. Em áreas onde o CVS se encontra subjacente sob sedimentos mais recentes (ex. Grupo Flysch Baixo Alentejo e formações cenozoicas), o uso de técnicas geofísicas é fundamental para a seleção de alvos. São também descritos exemplos sobre a aplicação de métodos eletromagnéticos, sísmicos e magnetotelúricos na identificação e caracterização de estruturas geológicas. A análise integrada de diferentes métodos geofísicos, complementados com informação geológica e geoquímica, constitui a melhor metodologia de prospeção, sendo essencial para a pesquisa de horizontes de mineralização. Considerando a FPI como uma das principais províncias metalogenéticas do mundo, é expectável que venham a ocorrer mais investimentos e assim serem identificados novos jazigos, inclusive com dimensão superior a 200 Mt. Através de projetos ID como o EXPLORA/Alentejo2020 e SmartExplorationTM/H2020 o LNEG contribui para um melhor conhecimento na FPI em cenários de prospeção near mining e green fields. Nesta perspetiva, são esperadas novas descobertas de jazigos à semelhança do que tem acontecido em Portugal, como por exemplo Lagoa Salgada (SFM-1992, Redcorp/EDM 2011, Redcorp/Ascendant/EDM-2017), Semblana (Somincor-AGC Lundin Mining, 2010), Monte Branco (Somincor-Lundin Mining, 2012) e Sesmarias (Maepa/Avrupa, 2014). A importância destes dados vai muito para além da prospeção mineira. Uma vez que alguns métodos utilizam propriedades físicas que podem ser relacionadas com contaminações ambientais. Certos métodos geofísicos como radiometria e magnetometria, resistividade e métodos elétricos em geral, podem ser utilizados também em trabalhos de investigação sobre background geoquímico, drenagem ácida de mina e dispersão de metais. Desta forma, a aplicação destes métodos promove também um conhecimento mais aprofundado noutras áreas de investigação relacionadas com a preservação do ambiente.info:eu-repo/semantics/publishedVersio

    Rifabutin-Loaded Nanostructured Lipid Carriers as a Tool in Oral Anti-Mycobacterial Treatment of Crohn s Disease

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    © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Oral anti-mycobacterial treatment of Crohn’s disease (CD) is limited by the low aqueous solubility of drugs, along with the altered gut conditions of patients, making uncommon their clinical use. Hence, the aim of the present work is focused on the in vitro evaluation of rifabutin (RFB)-loaded Nanostructured lipid carriers (NLC), in order to solve limitations associated to this therapeutic approach. RFB-loaded NLC were prepared by hot homogenization and characterized in terms of size, polydispersity, surface charge, morphology, thermal stability, and drug payload and release. Permeability across Caco-2 cell monolayers and cytotoxicity and uptake in human macrophages was also determined. NLC obtained were nano-sized, monodisperse, negatively charged, and spheroidal-shaped, showing a suitable drug payload and thermal stability. Furthermore, the permeability profile, macrophage uptake and selective intracellular release of RFB-loaded NLC, guarantee an effective drug dose administration to cells. Outcomes suggest that rifabutin-loaded NLC constitute a promising strategy to improve oral anti-mycobacterial therapy in Crohn’s disease.This research was funded by V-A POCTEP Program (0245_IBEROS_1_E) of EU (FEDER), Xunta de Galicia (Competitive Reference Groups, ED431C 2016/008 and ED431C2017/09-FEDER), as well as by Fundação para a Ciência e Tecnologia, Portugal (under iMED.ULisboa project Pest-UID/DTP/04138/2019).info:eu-repo/semantics/publishedVersio

    Population homogeneity for the antibody response to COVID-19 BNT162b2/Comirnaty vaccine is only reached after the second dose across all adult age ranges

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    ABSTRACT: While mRNA vaccines are administrated worldwide in an effort to contain the COVID-19 pandemic, the heterogeneity of the humoral immune response they induce at the population scale remains unclear. Here, in a prospective, longitudinal, cohort-study, including 1245 hospital care workers and 146 nursing home residents scheduled for BNT162b2 vaccination, together covering adult ages from 19 to 99 years, we analyse seroconversion to SARS-CoV-2 spike protein and amount of spike-specific IgG, IgM and IgA before vaccination, and 3-5 weeks after each dose. We show that immunogenicity after a single vaccine dose is biased to IgG, heterogeneous and reduced with increasing age. The second vaccine dose normalizes IgG seroconversion in all age strata. These findings indicate two dose mRNA vaccines is required to reach population scale humoral immunity. The results advocate for the interval between the two doses not to be extended, and for serological monitoring of elderly and immunosuppressed vaccinees.info:eu-repo/semantics/publishedVersio

    Rifabutin-Loaded Nanostructured Lipid Carriers as a Tool in Oral Anti-Mycobacterial Treatment of Crohn’s Disease

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    Oral anti-mycobacterial treatment of Crohn’s disease (CD) is limited by the low aqueous solubility of drugs, along with the altered gut conditions of patients, making uncommon their clinical use. Hence, the aim of the present work is focused on the in vitro evaluation of rifabutin (RFB)-loaded Nanostructured lipid carriers (NLC), in order to solve limitations associated to this therapeutic approach. RFB-loaded NLC were prepared by hot homogenization and characterized in terms of size, polydispersity, surface charge, morphology, thermal stability, and drug payload and release. Permeability across Caco-2 cell monolayers and cytotoxicity and uptake in human macrophages was also determined. NLC obtained were nano-sized, monodisperse, negatively charged, and spheroidal-shaped, showing a suitable drug payload and thermal stability. Furthermore, the permeability profile, macrophage uptake and selective intracellular release of RFB-loaded NLC, guarantee an effective drug dose administration to cells. Outcomes suggest that rifabutin-loaded NLC constitute a promising strategy to improve oral anti-mycobacterial therapy in Crohn’s diseaseThis research was funded by V-A POCTEP Program (0245_IBEROS_1_E) of EU (FEDER), Xunta de Galicia (Competitive Reference Groups, ED431C 2016/008 and ED431C2017/09-FEDER), as well as by Fundação para a Ciência e Tecnologia, Portugal (under iMED.ULisboa project Pest-UID/DTP/04138/2019)S

    TPCS/PBAT blown extruded films added with curcumin as a technological approach for active packaging materials

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    The development of active packaging is a relevant topic demanding the development of films with diverse properties to preserve specific foodstuff. The objective of this work was to obtain extruded TPCS/PBAT films containing curcumin and evaluate it as an active antimicrobial and antioxidant packaging to protect chia oil from oxidative degradation. Morphology, thermal, mechanical, antimicrobial, and antioxidant evaluation of the films were conducted to determine whether the presence of curcumin affected the film’s properties. Infrared Spectroscopy indicated that curcumin addition affected the crosslinking reaction between citric acid and starch, which explains the changes in hydrophilicity and mechanical strength of the films. The incorporation of curcumin conferred antimicrobial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria, as well as antioxidant activity. Films were tested as chia oil packaging, being verified that they successfully prevented oil degradation under accelerated stability test (60 °C for 7 days), demonstrating the feasibility of using TPCS/PBAT biodegradable films containing curcumin to obtain active packaging materials.Authors thank to CNPq (Chamada Universal– MCTI/CNPq Nº 14/2014, Processo 447768/2014-0), CAPES (Coordenação de Pessoal de Nível Superior Master's scholarship) and Fundação Araucária (Programa Universal/Pesquisa Básica e Aplicada 24/2012, protocolo 7334133700514041013) for the finantial support. This work was financially supported by Associate Laboratory LSRE-LCM (UID/EQU/50020/2019) funded by national funds through FCT/MCTES (PIDDAC), and Foundation for Science and Technology (FCT, Portugal). CIMO (UID/AGR/00690/2019) through FEDER under Program PT2020. To the national funding by FCT, P.I., through the institutional scientific employment program-contract for I.P. Fernandes contract.info:eu-repo/semantics/publishedVersio

    Report of Working Group on Widely Distributed Stocks (WGWIDE).

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    As a consequence of the impact of the COVID pandemic on international travel which prevented the traditional meeting from taking place, the Working Group on Widely Distributed Stocks (WGWIDE) met online via WebEx hosted by ICES. Prior to the 2020 meeting, the generic ToRs for species and regional working groups were re-prioritised by ACOM to allow the WG to focus primarily on those ToRs most applicable to the provision of advice. WGWIDE reports on the status and considerations for management of Northeast Atlantic mackerel, blue whiting, Western and North Sea horse mackerel, Northeast Atlantic boarfish, Norwegian springspawning herring, striped red mullet (Subareas 6, 8 and Divisions 7.a-c, e-k and 9.a), and red gurnard (Subareas 3, 4, 5, 6, 7, and 8) stocks. Northeast Atlantic (NEA) Mackerel. This stock is highly migratory and widely distributed throughout the Northeast Atlantic with significant fisheries is most ICES subareas. A diverse range of fleets from smaller artisanal, handline vessels to large (100m+) factory freezer vessels and modern RSW trawlers and purse seiners take part in what is one of the most valuable European fisheries. The assessment conducted in 2020 is an update assessment, based on the configuration agreed during the most recent inter-benchmark exercise in 2019 and incorporates the most recent data available from sampling of the commercial catch in 2019, the final 2019 egg survey SSB estimate, an updated recruitment index and tagging time series along with 2020 survey data from the IESSNS swept area survey. Advice is given based on stock reference points which were updated during a management strategy evaluation carried out in 2020. Following a strong increase from 2007 to 2014, SSB has been declining although it remains well above MSY Btrigger. Fishing mortality has been below FMSY since 2016. There have been a number of large year classes since 2001 with above average recruitment over much of the most recent decade. Blue Whiting. This pelagic gadoid is widely distributed in the eastern part of the North Atlantic. The 2020 update assessment followed the protocol from the most recent inter-benchmark in 2016 and used preliminary catch data from 2020. Due to the cancellation of the 2020 acoustic survey, this data was not available. The effect on the assessment was minimal and limited to increases in uncertainty of the terminal year estimates. The SSB continues to decrease from the most recent maximum in 2017 mainly due to below average recruitment since 2017, although it remains above MSY Btrigger. Fishing mortality has been above FMSY since 2014. Norwegian Spring Spawning Herring. This is one of the largest herring stocks in the world. It is highly migratory, spawning along the Norwegian coast and feeding throughout much of the Norwegian Sea. The 2020 assessment is based on an implementation of the XSAM assessment model introduced at the benchmark in 2016. This years’ assessment indicates that the stock is continuing to decline from the peak in 2008 of 7Mt to just above MSY Btrigger due to successive years of average or below average recruitment. Catch advice for 2021 is given on the basis of the agreed management plan and represents a substantial increase over the 2020 advice due to an upward revision in the estimate of the 2016 year-class which is considered to be the most significant year-class since 2004
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