999 research outputs found

    Surges and Si IV bursts in the solar atmosphere. Understanding IRIS and SST observations through RMHD experiments

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    Surges often appear as a result of the emergence of magnetized plasma from the solar interior. Traditionally, they are observed in chromospheric lines such as Hα\alpha 6563 \AA and Ca II 8542 \AA. However, whether there is a response to the surge appearance and evolution in the Si IV lines or, in fact, in many other transition region lines has not been studied. In this paper we analyze a simultaneous episode of an Hα\alpha surge and a Si IV burst that occurred on 2016 September 03 in active region AR12585. To that end, we use coordinated observations from the Interface Region Imaging Spectrograph (IRIS) and the Swedish 1-m Solar Telescope (SST). For the first time, we report emission of Si IV within the surge, finding profiles that are brighter and broader than the average. Furthermore, the brightest Si IV patches within the domain of the surge are located mainly near its footpoints. To understand the relation between the surges and the emission in transition region lines like Si IV, we have carried out 2.5D radiative MHD (RMHD) experiments of magnetic flux emergence episodes using the Bifrost code and including the non-equilibrium ionization of silicon. Through spectral synthesis we explain several features of the observations. We show that the presence of Si IV emission patches within the surge, their location near the surge footpoints and various observed spectral features are a natural consequence of the emergence of magnetized plasma from the interior to the atmosphere and the ensuing reconnection processes.Comment: 13 pages, 8 figures. The Astrophysical Journal (Accepted

    Different ventilatory responses to progressive maximal exercise test performed with either the arms or legs

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    OBJECTIVE: This study aimed to compare respiratory responses, focusing on the time-domain variability of ventilatory components during progressive cardiopulmonary exercise tests performed on cycle or arm ergometers. METHODS: The cardiopulmonary exercise tests were conducted on twelve healthy volunteers on either a cycle ergometer or an arm ergometer following a ramp protocol. The time-domain variabilities (the standard deviations and root mean squares of the successive differences) of the minute ventilation, tidal volume and respiratory rate were calculated and normalized to the number of breaths. RESULTS: There were no significant differences in the timing of breathing throughout the exercise when the cycle and arm ergometer measurements were compared. However, the arm exercise time-domain variabilities for the minute ventilation, tidal volume and respiratory rate were significantly greater than the equivalent values obtained during leg exercise. CONCLUSION: Although the type of exercise does not influence the timing of breathing when dynamic arm and leg exercises are compared, it does influence time-domain ventilatory variability of young, healthy individuals. The mechanisms that influence ventilatory variability during exercise remain to be studied

    Metodologia científica: aperfeiçoamento metodológico para digestão assistida via micro-ondas na análise mineral de feijoeiro comum (Phaseolus vulgaris L.).

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    O objetivo deste trabalho foi determinar a eficiência na recuperação de minerais por meio do método de digestão em micro-ondas adaptado e analisar se essa recuperação é confiável com o uso de menor volume de ácido nítrico, otimizando-se, desta forma, o método. Neste comunicado, são relatadas todas as etapas e procedimentos para a condução das análises, assim como, discutidos os resultados e o alcance dos principais objetivos do trabalho com base em análise estatística e cálculo do Z Score.bitstream/item/30834/1/comt196.pd

    Acid vapor sample decomposition in open vessel microwave.

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    Micrawave decomposition has been increasingly used hr a large number of samples. A method using an open vessel microwave was used for biological sample preparation with nitric acid vapors under atmospheric pressure. A lab made Teflon@ support suited with four cups, which received the samples, was inserted in the microwave vessel. These cups were used to weight 30 mg of certi5ed re5wence materials such as spinach and apple leaves, which received 150 pL of d.i. water to improve the micrawave e%ciency. This mixture was exposed to acid vapor stemmed from 15 mL of concentrated nitrie acid plsced in the bottom of the vessel hr decompoeition. The maximum microwave temperature, 115'C, was reached in 4 min. This condition was rnaintained hr 20 min to sllow complete decomposition of the sample. The deeomposed sample, in the cup, was diluted to 1.0 mL of d.i. water, shaken and centrifuged. The cups were than placed directed into an autosampler for Co and Fe analysis in an atomic absorption graphite fumace spectrometer

    species identification, distribution, and new host records in Portugal

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    Funding Information: This research was supported by the “Fundação para a Ciência e a Tecnologia” (FCT, Portugal) and the European Social Funds, through the “Programa Operacional Regional Centro”, under the Ph.D. fellowship 2020.05541.BD and through the R&D Unit, UIDB/04551/2020 (GREEN-IT—Bioresources for Sustainability). Acknowledgments Funding Information: This research was supported by the “Fundação para a Ciência e a Tecnologia” (FCT, Portugal) and the European Social Funds, through the “Programa Operacional Regional Centro”, under the Ph.D. fellowship 2020.05541.BD and through the R&D Unit, UIDB/04551/2020 (GREEN-IT—Bioresources for Sustainability). Publisher Copyright: Copyright © 2023 Rusinque, Camacho, Serra, Nóbrega and Inácio.Considered one of the most devastating plant parasitic nematodes worldwide, Meloidogyne spp. (commonly known as the root-knot nematodes (RKNs)) are obligate sedentary endoparasites that establish in the roots, causing hyperplasia and hypertrophy of surrounding cells, triggering the formation of galls. These galls will affect root development and physiology, leading to substantial yield losses. During 2017–2022, an extensive survey of Meloidogyne species was undertaken in Portugal (mainland and islands). A total of 1,071 samples were collected by the National Plant Protection Organization (DGAV) and private farmers from different regions of the country and were analysed at the Laboratory of Nematology (NemaINIAV). Samples in which the presence of Meloidogyne sp. was detected were used to perform bioassays to obtain females and juveniles for further studies. Since the accurate identification of RKNs is an important aspect of crop management, morphological and biochemical characterisation was performed. The most common morphological features were observed, showing consistency with previous descriptions of the genus. The biochemical identification using the esterase (EST) phenotype revealed the phenotypes of Meloidogyne arenaria, M enterolobi, M. hispanica, M. hapla, M. incognita, M javanica, and M. luci. Meloidogyne incognita and M. javanica were found to be the most prevalent species in the different regions followed by M. arenaria and M. hapla. This is the first distribution report performed in Portugal on RKNs, contributing to the development of management strategies and to updated information on the status of these pests in Europe.publishersversionpublishe

    The cholesterol 24-hydroxylase activates autophagy and decreases mutant huntingtin build-up in a neuroblastoma culture model of Huntington’s disease

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    Objective Compromised brain cholesterol turnover and altered regulation of brain cholesterol metabolism have been allied with some neurodegenerative diseases, including Huntington’s disease (HD). Following our previous studies in HD, in this study we aim to investigate in vitro in a neuroblastoma cellular model of HD, the effect of CYP46A1 overexpression, an essential enzyme in cholesterol metabolism, on huntingtin aggregation and levels. Results We found that CYP46A1 reduces the quantity and size of mutant huntingtin aggregates in cells, as well as the levels of mutant huntingtin protein. Additionally, our results suggest that the observed beneficial effects of CYP46A1 in HD cells are linked to the activation of autophagy. Taken together, our results further demonstrate that CYP46A1 is a pertinent target to counteract HD progression.This work was supported by Brainvectis and E.rare: E-Rare Joint Transnational Call for Proposals 2017 “Transnational Research Projects for Innovative Therapeutic Approaches for Rare Diseases”. CN laboratory is supported by the French Muscular Dystrophy Association (AFM-Téléthon), the Ataxia UK, and the Fundação para a Ciência e Tecnologia (project ALG-01-0145-FEDER-29480 “SeGrPolyQ”). AM is supported by a Ph.D. fellowship from FCT (SFRH/BD/133192/2017)info:eu-repo/semantics/publishedVersio

    A flexible-docking approach for the design of novel cancer peptidomimetic drugs

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    Cancer is the second leading cause of death worldwide and the lack of alternative therapies has kept patients dependent on classic chemotherapy. The most occurring form of cancer amongst women is breast cancer and the triple negative cell subtype (TNBC) is responsible for a high metastatic and mortality rate, as it presents molecular and genetic shifts, lacks specific targeting and responds poorly to existing therapies. Recent studies have provided convincing evidence that the therapeutic outcome of chemotherapy may be affected by the expression and activity of receptor tyrosine kinases and their phosphatase pathways (MAPK/ERK, PI3/AKT, among others). These proteins are implicated in mechanisms of cell survival, drug resistance and Epithelial-Mesenchymal Transition (EMT), and are therefore key targets for TNBC cancer cell subtype. However, many inhibitors developed for these targets have not succeeded at a clinical level and present low solubility. As a result of the pronounced decline in productivity experienced by drug discovery efforts in the last years, novel approaches to the rational design of new drugs are now being pursued. A potential solution might be the use of natural or synthetic peptides and peptidomimetics targeting protein-protein interactions essential for signaling networks function. The combination of several bioinformatic approaches (docking, virtual screening, pharmacophore models, among others) allows the use of the vast amount of existing information on available compounds and protein-protein interactions in structural databases. In this study we designed a procedure for small peptidomimetics structure-based rational drug design capable of blocking the active sites of SNAiL1, a protein that has been suggested as a potent repressor of E-cadherin expression and consequently, as an inducer of EMT transition in TNBCs. A random library was created using a composite approach for drug-like compound identification from the PubChem and Development Therapeutics NCI/NIH compound databases, which combined structure-based virtual screening (known motifs of peptide structures within proteins and small molecules) and Z-score comparison. Docking studies were performed to map the polypeptides activity and stability: (1) point alteration studies using non-natural aminoacids for helical stability over a wider range (since linear peptides adopt many confirmations in aqueous solution) using Ramachandran plot dihedral angles estimation; (2) quantitative structure-activity relationships (QSAR) using radical modification chemical studies and (3) umbrella sampling for dissociations studies. The peptidomimetic SNAiL1 model created suggested at least two radical modifications for a strong inhibition

    Efeito de câmara simuladora de radiação solar sobre cor e tempo de cocção de grãos de feijão carioca.

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    O objetivo do trabalho foi analisar o efeito da câmara simuladora de radiação solar sobre as características de cor e tempo de cocção de feijão carioca.CONAFE
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