1,967 research outputs found

    Fetal Heart Rate Fragmentation

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    This article was supported by National Funds through FCT– Fundação para a Ciência e a Tecnologia, I.P., within CINTESIS, R&D Unit (reference UIDB/4255/2020)info:eu-repo/semantics/publishedVersio

    Factorial validity and measurement invariance of the uncertainty response scale

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    Abstract This study presents the adaptation of the Uncertainty Response Scale (Greco & Roger, Pers. Individ. Differ, 31:519-534, 2001) to Portuguese. This instrument was administered to a non-clinical community sample composed of 1596 students and professionals, allowing a thorough validity and invariance analysis by randomly dividing participants into three subsamples to perform: an exploratory factor analysis (sample one: N = 512); a preliminary confirmatory factor analysis to identify the final solution for the scale (sample two: N = 543); and the confirmatory factor analysis (sample three: N = 541). Samples two and three were also used for multi-group analysis to assess measurement invariance, invariance across gender, sociocultural levels, and students versus active professionals. Results showed the scale reflects the original factorial structure, as well as good internal consistency and overall good psychometric qualities. Invariance results across groups reached structural invariance which provides a confident invariance measurement for this scale, while invariance across gender and sociocultural levels reached metric invariance. Accordingly, differences between these groups were explored, by comparing means with multi-group analysis to establish the scale's sensitivity toward social vulnerability, by demonstrating the existence of statistically significant differences regarding gender and sociocultural levels on how individuals cope with uncertainty, specifically in terms of emotional strategies, as a self-defeating strategy. Thus, females scored higher on emotional uncertainty, as well as low sociocultural levels, compared with higher ones. Therefore, it is proposed that this scale could be a sound alternative to explore strategies for coping with uncertainty, when considering social, economic, or other environmental circumstances that may affect them

    Antioxidant, allelopathic and toxic activity of Ochna serrulata

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    Ochna serrulata (Ochnaceae) is an ornamental plant introduced into Brazil from Asia and Africa. Species of the Ochna genus are rich in phenolic compounds, mainly flavonoids. The biological screening of extracts and fractions showed that this plant exhibited a significant antioxidant activity, when evaluated by the DPPH and reducing potential assays. Ochna serrulata also demonstrated slight toxic activity against Artemia salina and a potential inhibitory allelopathic activity, when evaluated using the Lactuca sativa seed germination test. The ethyl acetate fraction, the most active one, was partitioned on a silica gel column to obtain epicatechin, which showed potential antioxidant activity.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Antioxidant, allelopathic and toxic activity of Ochna serrulata

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    Ochna serrulata (Ochnaceae) is an ornamental plant introduced into Brazil from Asia and Africa. Species of the Ochna genus are rich in phenolic compounds, mainly flavonoids. The biological screening of extracts and fractions showed that this plant exhibited a significant antioxidant activity, when evaluated by the DPPH and reducing potential assays. Ochna serrulata also demonstrated slight toxic activity against Artemia salina and a potential inhibitory allelopathic activity, when evaluated using the Lactuca sativa seed germination test. The ethyl acetate fraction, the most active one, was partitioned on a silica gel column to obtain epicatechin, which showed potential antioxidant activity.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Avaliação da capacidade de adesão de células de biofilmes de Candida após tratamento com nanopartículas de prata

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    O objetivo deste estudo foi investigar a capacidade de adesão a células epiteliais humanas e a superfície de poliestireno de leveduras viáveis recuperadas de biofilmes de Candida albicans e Candida glabrata tratados com nanopartículas de prata (NP). Métodos: Biofilmes de Candida (48 hrs) foram formados em placas de microtitulação de 6 poços e tratados por 24 horas com NP (5 nm) nas concentrações de 13,5 e 54 mg/L. Suspensões de células de Candida (107 células viáveis/mL em RPMI 1640) provenientes dos biofilmes tratados com NP foram adicionadas a monocamadas de células HeLa e a poços vazios de placas de microtitulação de 24 poços (para estudar adesão a poliestireno). Após 2 horas de contato, a adesão das leveduras foi determinada usando a coloração com violeta cristal. Resultados: A capacidade de adesão de leveduras viáveis a células HeLa e a superfícies de poliestireno foi significativamente reduzida, e esta redução foi maior quando os biofilmes foram pré-tratados com NP na concentração de 54 mg/L. Ainda, a quantidade de leveduras aderidas das duas cepas diferiu de acordo com o substrato (células epiteliais e superfície de poliestireno). Conclusão: NP podem induzir modificações em leveduras viáveis, as quais podem diminuir a disseminação de infecções por Candida, principalmente em pacientes imunocomprometidos

    Induction of a Protective Response in Mice by the Dengue Virus NS3 Protein Using DNA Vaccines

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    The dengue non-structural 3 (NS3) is a multifunctional protein, containing a serino-protease domain, located at the N-terminal portion, and helicase, NTPase and RTPase domains present in the C-terminal region. This protein is considered the main target for CD4+ and CD8+ T cell responses during dengue infection, which may be involved in protection. However, few studies have been undertaken evaluating the use of this protein as a protective antigen against dengue, as well as other flavivirus. In the present work, we investigate the protective efficacy of DNA vaccines based on the NS3 protein from DENV2. Different recombinant plasmids were constructed, encoding either the full-length NS3 protein or only its functional domains (protease and helicase), fused or not to a signal peptide (t-PA). The recombinant proteins were successfully expressed in transfected BHK-21 cells, and only plasmids encoding the t-PA signal sequence mediated protein secretion. Balb/c mice were immunized with the different DNA vaccines and challenged with a lethal dose of DENV2. Most animals immunized with plasmids encoding the full-length NS3 or the helicase domain survived challenge, regardless of the presence of the t-PA. However, some mice presented clinical signs of infection with high morbidity (hind leg paralysis and hunched posture), mainly in animal groups immunized with the DNA vaccines based on the helicase domain. On the other hand, inoculation with plasmids encoding the protease domain did not induce any protection, since mortality and morbidity rates in these mouse groups were similar to those detected in the control animals. The cellular immune response was analyzed by ELISPOT with a specific-CD8+ T cell NS3 peptide. Results revealed that the DNA vaccines based on the full-length protein induced the production of INF-γ, thus suggesting the involvement of this branch of the immune system in the protection

    Genotypic and phenotypic diversity of Bacillus spp. isolated from steel plant waste

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    Background: Molecular studies of Bacillus diversity in various environments have been reported. However, there have been few investigations concerning Bacillus in steel plant environments. In this study, genotypic and phenotypic diversity and phylogenetic relationships among 40 bacterial isolates recovered from steel plant waste were investigated using classical and molecular methods. Results: 16S rDNA partial sequencing assigned all the isolates to the Bacillus genus, with close genetic relatedness to the Bacillus subtilis and Bacillus cereus groups, and to the species Bacillus sphaericus. tDNA-intergenic spacer length polymorphisms and the 16S–23S intergenic transcribed spacer region failed to identify the isolates at the species level. Genomic diversity was investigatedby molecular typing with rep (repetitive sequence) based PCR using the primer sets ERIC2 (enterobacterial repetitive intergenic consensus), (GTG)5, and BOXAIR. Genotypic fingerprinting of the isolates reflected high intraspecies and interspecies diversity. Clustering of the isolates using ERIC-PCR fingerprinting was similar to that obtained from the 16S rRNA gene phylogenetic tree, indicating the potential of the former technique as a simple and useful tool for examining relationships among unknown Bacillus spp. Physiological, biochemical and heavy metal susceptibility profiles also indicated considerable phenotypic diversity. Among the heavy metal compounds tested Zn, Pb and Cu were least toxic to the bacterial isolates, whereas Ag inhibited all isolates at 0.001 mM. Conclusion: Isolates with identical 16S rRNA gene sequences had different genomic fingerprints and differed considerably in their physiological capabilities, so the high levels of phenotypic diversity found in this study are likely to have ecological relevance

    Multilayer thin-film optical filters for reflectance-based malaria diagnostics

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    Malaria diagnosis relies on optical microscopy and/or rapid diagnostic tests based on detecting specific malaria antigens. The clinical sensitivity of these methods is highly dependent on parasite density, with low levels of detection at low parasite density, challenging the worldwide malaria elimination efforts. Therefore, there is a need for diagnostic methods with higher sensitivity, demanding innovative diagnostics devices able to detect malaria at low parasite density and at early stages of the disease. We propose an innovative optical device for malaria diagnosis, based on optical reflectance spectrophotometry, for the detection of parasites through the quantification of haemozoin. For this purpose, a set of eight thin-film optical filters, based on multilayer stacks of MgO/TiO2 and SiO2/TiO2 thin-films, with high transmittance and low full width at half maximum (FWHM) at specific wavelengths, was designed and fully characterized (both numerically and experimentally). A preliminary assessment of its potential to reconstruct the original spectra of red blood cells was performed, both in uninfected and Plasmodium falciparum-infected samples. The obtained results show that, although the experimental filters have a non-ideal performance characteristic, they allow us to distinguish, based on only 8 discrete points in the optical spectrum, between healthy and malaria infected samples, up to a detection limit of 12 parasites/μL of red blood cells. Those results enhance the potential of using such a device for malaria diagnostics, aiming for non-invasiveness.Project NORTE-01-0145-FEDER-028178 funded by NORTE 2020 Portugal Regional Operational Program under PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund and the Fundação para a Ciência e Tecnologia (FCT), IP. This work was also supported by national funds, through the Portuguese FCT, under the reference projects UIDB/04436/2020, UIDP/04436/2020, UIDB/50026/2020 and UIDP/50026/2020, and by the ICVS Scientific Microscopy Platform, member of the national infrastructure PPBIPortuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122). V. Baptista thanks FCT for the SFRH/BD/145427/2019 grant. Maria Isabel Veiga thanks FCT for her contract funding provided through 2020.03113.CEECIND. Susana Catarino thanks FCT for her contract funding provided through 2020.00215.CEECIN
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