3,361 research outputs found

    Pervasive intelligent models to predict the outcome of COVID-19 patients

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    Nowadays, there is an increasing need to understand the behavior of COVID-19. After the Directorate-General of Health of Portugal made available the infected patient’s data, it became possible to analyze it and gather some conclusions, obtaining a better understanding of the matter. In this context, the project developed—ioCOVID19—Intelligent Decision Support Platform aims to identify patterns and develop intelligent models to predict and support clinical decisions. This article explores which typologies are associated with different outcomes to help clinicians fight the virus with a decision support system. So, to achieve this purpose, classification algorithms were used, and one target was studied—Patients outcome, that is, to predict if the patient will die or recover. Regarding the obtained results, the model that stood out is composed of scenario s4 (composed of all comorbidities, symptoms, and age), the decision tree algorithm, and the oversampling sampling method. The obtained results by the studied metrics were (in order of importance): Sensitivity of 95.20%, Accuracy of 90.67%, and Specificity of 86.08%. The models were deployed as a service, and they are part of a clinical decision support system that is available for authorized users anywhere and anytime.This research was funded by Portugal 2020 program through NORTE-01-02B7-FEDER-048344

    Electron transfer driven decomposition of adenine and selected analogs as probed by experimental and theoretical methods

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    We report on a combined experimental and theoretical study of electron transfer induced decomposition of adenine and a selection of analogue molecules in collisions with potassium atoms (K). Time-of-flight negative ion mass spectra have been obtained in a wide collision energy range (6–68 eV in the centre-of-mass frame), providing a comprehensive investigation of the fragmentation patterns of purine, adenine, 9-methyl adenine, 6-dimethyl adenine and 2-D adenine. Following our recent communication about selective hydrogen loss from the transient negative ions (TNI) produced in these collisions [T. Dunha et al. J. Chem. Phys. 148, 021101 (2018)], this work focuses on the production of smaller fragment anions. In the low-energy part of the present range, several dissociation channels that are accessible in free electron attachment experiments are absent from the present mass spectra, notably NH2 loss from adenine and 9-methyl adenine. This can be understood in terms of a relatively long transit time of the K+ cation in the vicinity of the TNI tending to enhance the likelihood of intramolecular electron transfer. In this case, the excess energy can be redistributed through the available degrees of freedom inhibiting fragmentation pathways. Ab initio theoretical calculations were performed for 9-methyl adenine (9-mAd) and adenine (Ad) in the presence of a potassium atom and provided a strong basis for the assignment the lowest unoccupied molecular orbitals accessed in the collision process

    Surface photochemistry: benzophenone as a probe for the study of silica and reversed-phase silica surfaces

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    This work reports the use of benzophenone, a very well characterized probe, to study new hosts: two reversed-phase silicas. Laser-induced room temperature luminescence of argon purged solid powdered samples of benzophenone adsorbed onto the two different reversed-phase silicas, RP-18 and RP-8, revealed the existence of a low energy emission band in contrast with the benzophenone adsorbed on 60 A pore silica, where only triplet benzophenone emits. This low energy emission band was identified as the fluorescence of the ketyl radical of benzophenone, which is formed as the result of a hydrogen atom abstraction reaction of the triplet excited benzophenone from the alkyl groups of the surface of the reversed silicas. Such emission does not exist for benzophenone adsorbed onto 60 A pore silica. Room temperature phosphorescence was obtained in argon purged samples for all the surfaces under use. The decay times of the benzophenone emission vary greatly with the alkylation of the silica surface when compared with "normal" silica surface. A lifetime distributions analysis has shown that the shortest lifetimes for the benzophenone emission exist in the former case. Triplet-triplet absorption of benzophenone was detected in all cases and is the predominant absorption in the case of 60 A pore silica, while benzophenone ketyl radical formation occurs in the case of the reversed silicas. Diffuse reflectance laser. ash photolysis and gas chromatography-mass spectrometry techniques provided complementary information, the former about transient species and the latter regarding the final products formed after laser irradiation, both at 266 nm or 355 nm. Product analysis and identification show that the degradation photoproducts are dependent on the excitation wavelength, the photochemistry being much more rich and complex in the 266 nm excitation case, where an alpha-cleavage reaction occurs. A detailed mechanistic analysis is proposed

    Compilation, revision, and annotation of DNA barcodes of marine invertebrate Non-Indigenous Species (NIS) occurring in european coastal regions

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    The script developed to create the DNA sequence reference library is available at https://github.com/tadeu95/Curated-BINs-Reference-Library (accessed on 25 January 2023). Metabarcoding datasets will be made available upon request since they belong to a study that is not published yet.The introduction of non-indigenous species (NIS) is one of the major threats to the integrity of European coastal ecosystems. DNA-based assessments have been increasingly adopted for monitoring NIS. However, the accuracy of DNA-based taxonomic assignments is largely dependent on the completion and reliability of DNA barcode reference libraries. As such, we aimed to compile and audit a DNA barcode reference library for marine invertebrate NIS occurring in Europe. To do so, we compiled a list of NIS using three databases: the European Alien Species Information Network (EASIN), the Information System on Aquatic Non-indigenous and Cryptogenic Species (AquaNIS), and the World Register of Introduced Marine Species (WRiMS). For each species, we retrieved the available cytochrome c oxidase subunit I (COI) mitochondrial gene sequences from the Barcode of Life Data System (BOLD) and used the Barcode, Audit & Grade System (BAGS) to check congruence between morphospecies names and Barcode Index Numbers (BINs). From the 1249 species compiled, approximately 42% had records on BOLD, among which 56% were discordant. We further analyzed these cases to determine the causes of the discordances and attributed additional annotation tags. Of the 622 discordant BINs, after revision, 35% were successfully solved, which increased the number of NIS detected in metabarcoding datasets from 12 to 16. However, a fair number of BINs remained discordant. Reliability of reference barcode records is particularly critical in the case of NIS, where erroneous identification may trigger action or inaction when not required.This research was funded by national funds through the Foundation for Science and Technology (FCT I.P.), grant number PTDC/BIA-BMA/29754/2017 (NIS-DNA: Early detection and monitoring of non-indigenous species (NIS) in coastal ecosystems based on high-throughput sequencing tools) and by the “Contrato-Programa” UIDB/04050/2020. Financial support granted by the FCT I.P. to S.D. (CEECIND/00667/2017) is also acknowledged. A.S.L. (UI/BD/150871/2021) and J.T.F. (UI/BD/150910/2021) are supported by the Collaboration Protocol for Financing the Multiannual Research Grants Plan for Doctoral Students with financial support from FCT I.P. and the European Social Fund under the Northern Regional Operational Program—Norte2020

    Electron microprobe analysis of cryolite

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    Comunicação apresentada em: EMAS 2013 : 13th European Workshop on Modern Developments and Applications in Microbeam Analysis, Centro de Congressos da Alfândega do Porto, Portugal, 12 to 16 May 2013A sample of cryolite was studied with a JEOL JXA 8500-F electron microprobe under several operating conditions. A TAP crystal was used to analyse Na and Al and a LDE1 crystal to analyse F. As F and Na are both highly "volatile" elements, special care must be taken during analysis. The measurement order of Na, F and Al is not irrelevant and optimum conditions may also result in different combinations of accelerating voltage, beam current, beam size or counting times. Relevant X-ray signals were recorded in order to investigate the behaviour of the Na Ka and F Ka counts with elapsed time. The incident beam current was also recorded at the same time. In a clear contrast to what has normally been reported in the EPMA analysis of aluminosilicates and silicate glasses, we found that the Na X-ray counts increase with time. This increment of X-rays intensities for sodium in cryolite depends on the operating conditions and is accompanied by a strong migration of fluorine from the beam excitation volume, leading to a decrease in F X-ray counting rates. It was also observed that higher incident beam currents induce higher radiation damage in the mineral. The current instability is consistent with possible electron induced dissociation in the cryolite structure. An analytical protocol was achieved for 6 kV and 15kV accelerating voltage for the correct EPMA analysis of cryolite

    Caracterização molecular de genótipos do gênero Manihot Mill (Euphorbiaceae) por meio de marcadores RAPD.

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    Espécies silvestres do gênero Manihot são importantes reservatórios de alelos de interesse a serem transferidos para espécies cultivadas visando o desenvolvimento de variedades melhoradas que sejam mais resistentes a fatores bióticos e abióticos e que expressem maior produtividade.Em paralelo aconteceram também os seguintes eventos: V Seminário de Pesquisa do Recôncavo da Bahia; V Seminário Estudantil de Pesquisa da UFRB; V Seminário da Pós-Graduação da UFRB; II Seminário Regional de Pesquisa da EBDA; 5ª Jornada Científica da Embrapa Mandioca e Fruticultura; VIII Seminário Estudantil de Pesquisa e Extensão da FAMAM; Semana de Ciência, Tecnologia e Inovação no Agronegócio; Fórum de Gestores de Iniciação Científica e Tecnológica da Bahia; II Simpósio Baiano de Defesa Agropecuária; I Semana de Educação Tutorial da UFRB

    Variabilidade genética entre acessos de espécies silvestres de manihot e cultivares de mandioca por meio de marcadores RAPD.

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    Este trabalho tem por objetivo realizar a caracterização molecular de acessos silvestres de Manihot e cultivares de mandioca com o intuito de avaliar a variabilidade genética disponível para ser explorada dentro do programa de melhoramento genético de mandioca da Embrapa Mandioca e Fruticultura. Foram caracterizados por meio de marcador molecular RAPD 20 acessos de espécies do gênero Manihot, oriundos da coleção de trabalho da Embrapa. Os dados obtidos foram submetidos à análise multivariada de agrupamento a partir da matriz de distância calculada pelo índice de dissimilaridade de Jaccard. Os agrupamentos hierárquicos foram obtidos pelo método UPGMA e a validação dos agrupamentos determinada pelo coeficiente de correlação cofenético. O marcador molecular RAPD mostrou-se eficiente na separação dos genótipos demonstrando existir variabilidade genética suficiente para ser explorada no melhoramento genético de mandioca

    Osteochondritis dissecans of the knee. Pearls and pitfalls of anatomical reduction and secure fixation

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    Osteochondritis dissecans of the knee is characterized by sterile necrosis of the subchondral bone and typically affects skeletally immature patients. When left untreated, osteochondritis dissecans can lead to early-onset osteoarthritis, resulting in pain and disability. This study shows the pearls and pitfalls of an arthroscopic technique of fixation performed successfully using a bioabsorbable nail for unstable osteochondritis dissecans lesions located in the medial femoral condyle of the knee
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