249 research outputs found
Sistemas dunares do litoral de Esposende
Ciência Viva - A.N.C.C.T. (Programa Operacional Ciência Tecnologia Inovação - POCTI)Ministério da Ciência e da Tecnologia - Ciência Viva - Biologia no Verão 2001
Influence of saliva and mucin on the adhesion of Candida oral clinical isolates
Objectives: This research work intends to clarify the role of artificial saliva, in particularly the role of mucin, a salivary protein, on the surface properties and adhesion ability of Candida spp. oral clinical isolates to abiotic surfaces. Methods: Four oral clinical isolates of Candida spp. were used: two Candida albicans strains (AC; AM) and two Candida parapsilosis strains (AD; AM2). The strains were isolated from patients using oral prosthesis. The microorganisms were cultured in the absence or presence of mucin and artificial saliva, and their adhesion to an abiotic surface (coated with mucin and artificial saliva) was evaluated. Results: The presence of mucin per se onto the abiotic surface decreased the adhesion of all strains, although the combination of mucin with artificial saliva had reduced this effect. No direct correlation between adhesion and the surface free energies of adhesion of the microorganisms was found. Significance: Candida spp. were human commensal microorganisms that became pathogenic when the host immune defenses were compromised. Medical devices were colonized by Candida spp. particularly, oral prostheses, which might lead to the degradation of the prostheses and systemic infections. The salivary secretions that constantly cover the oral cavity influenced Candida spp. adhesion process. Therefore, it was important to understand the interactions between Candida spp., salivary proteins and the characteristic of oral prosthesis when developing materials for oral prostheses.The authors thank the Project “BioHealth-Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. The would also like to thank the Fundação para a Ciência e Tecnologia for the Strategic Project Pest-OE/EQB/LA0023/2013 and Fundação para a Ciência e Tecnologia (FCT) for Ana Oliveira PhD Grant (SFRH/BD/68588/2010) and Catarina L. Seabra PhD Grant (SFRH/BD/89001/2012). The authors would also like to acknowledge Professora Rosário Oliveira, which is no longer with us, for her exceptional contribution and dedication to this work
Correlation between sarcopenia and atherosclerosis/cardiovascular risk factors in the elderly
A Comparative Study
This research was funded by EU funds through the FEDER European Regional Development Fund (project LISBOA-02-0145-FEDER-031311) project LA/P/0056/2020 of Institute of Molecular Sciences, and LA/P/0140/2020 of i4HB, project UID/EEA/00066/2020 from the Center of Technology and Systems, and from the Instituto Politécnico de Lisboa with IPL/2018/STREAM_ISEL and IPL/2020/AGE-SPReS_ISEL projects. APCR and AMF thank the Instituto Superior Técnico for the scientific employment contracts IST-ID/119/2018 and IST-ID/131/2018, respectively.
Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.Aiming to develop a nanoparticle-based optical biosensor using gold nanoparticles (AuNPs) synthesized using green methods and supported by carbon-based nanomaterials, we studied the role of carbon derivatives in promoting AuNPs localized surface plasmon resonance (LSPR), as well as their morphology, dispersion, and stability. Carbon derivatives are expected to work as immobi-lization platforms for AuNPs, improving their analytical performance. Gold nanoparticles (AuNPs) were prepared using an eco-friendly approach in a single step by reduction of HAuCl4·3H2O using phytochemicals (from tea) which act as both reducing and capping agents. UV–Vis spectroscopy, transmission electron microscopy (TEM), zeta potential (ζ-potential), and X-ray photoelectron spectroscopy (XPS) were used to characterize the AuNPs and nanocomposites. The addition of reduced graphene oxide (rGO) resulted in greater dispersion of AuNPs on the rGO surface compared with carbon-based nanomaterials used as a support. Differences in morphology due to the nature of the carbon support were observed and are discussed here. AuNPs/rGO seem to be the most promising candidates for the development of LSPR biosensors among the three composites we studied (AuNPs/G, AuNPs/GO, and AuNPs/rGO). Simulations based on the Mie scattering theory have been used to outline the effect of the phytochemicals on LSPR, showing that when the presence of the residuals is limited to the formation of a thin capping layer, the quality of the plasmonic resonance is not affected. A further discussion of the application framework is presented.publishersversionpublishe
Whole Genome Sequencing Refines Knowledge on the Population Structure of Mycobacterium bovis from a Multi-Host Tuberculosis System
Classical molecular analyses of Mycobacterium bovis based on spoligotyping and Variable Number Tandem Repeat (MIRU-VNTR) brought the first insights into the epidemiology of animal tuberculosis (TB) in Portugal, showing high genotypic diversity of circulating strains that mostly cluster within the European 2 clonal complex. Previous surveillance provided valuable information on the prevalence and spatial occurrence of TB and highlighted prevalent genotypes in areas where livestock and wild ungulates are sympatric. However, links at the wildlife–livestock interfaces were established mainly via classical genotype associations. Here, we apply whole genome sequencing (WGS) to cattle, red deer and wild boar isolates to reconstruct the M. bovis population structure in a multi-host, multi-region disease system and to explore links at a fine genomic scale between M. bovis from wildlife hosts and cattle. Whole genome sequences of 44 representative M. bovis isolates, obtained between 2003 and 2015 from three TB hotspots, were compared through single nucleotide polymorphism (SNP) variant calling analyses. Consistent with previous results combining classical genotyping with Bayesian population admixture modelling, SNP-based phylogenies support the branching of this M. bovis population into five genetic clades, three with apparent geographic specificities, as well as the establishment of an SNP catalogue specific to each clade, which may be explored in the future as phylogenetic markers. The core genome alignment of SNPs was integrated within a spatiotemporal metadata framework to further structure this M. bovis population by host species and TB hotspots, providing a baseline for network analyses in different epidemiological and disease control contexts. WGS of M. bovis isolates from Portugal is reported for the first time in this pilot study, refining the spatiotemporal context of TB at the wildlife–livestock interface and providing further support to the key role of red deer and wild boar on disease maintenance. The SNP diversity observed within this dataset supports the natural circulation of M. bovis for a long time period, as well as multiple introduction events of the pathogen in this Iberian multi-host system.info:eu-repo/semantics/publishedVersio
Actividades experimentais nas escolas através de uma interacção com a universidade
A forma como a ciência é ensinada nas escolas afecta profundamente a percepção que os estudantes têm do mundo que os rodeia e
consequentemente a escolha de uma futura carreira nas ciências. Por outro lado, a abertura da escola à comunidade envolvente, proporciona
as condições para a sua participação activa na vida escolar, assim como a promoção do sucesso escolar, através da formação integral dos
alunos, dotando-os das competências científicas, tecnológicas e sócio-culturais necessárias a sólidas opções futuras.
A química como uma ciência de cariz experimental oferece aos estudantes uma melhor compreensão dos conceitos teóricos leccionados. Este
trabalho descreve actividades experimentais realizadas no âmbito de um intercâmbio entre a Escola Secundária/3 de Barcelinhos e o
Departamento de Química. Os projectos desenvolvidos foram “Museu das Ciências” na disciplina de Área Projecto do 12º ano de
escolaridade. A actividade A Ciência na investigação criminal foi baseada nas oficinas apresentadas no projecto Sentidos da Ciência [1].
Estas actividades experimentais executadas em colaboração entre as escolas e a universidade contribuem para uma maior motivação dos
alunos, uma formação científica mais sólida e um conhecimento mais integrado
Cr(VI)-induced malignant transformation of a bronchial epithelial cell line association with altered mitochondria and bioenergetic phenotypes
Erratum: Moreira, J., et al., Spin-Coated Polysaccharide-Based Multilayered Freestanding Films with Adhesive and Bioactive Moieties. Molecules 2020, 25, 840
Erratum: Moreira, J., et al., Spin-Coated Polysaccharide-Based Multilayered Freestanding
Films with Adhesive and Bioactive Moieties. Molecules 2020, 25, 840. DOI: 10.3390/molecules25040840The authors wish to make changes to the published paper 11 j. 1. UV-Vis Analysis of Catechol-Modified Polymers In the original manuscript theie is a mistake concerning the word "Wavenumber" in the X-Coordinate in Figure 1. Tile corrected word is "Wavelength". Tlx- A uthors also wish to change mg«mL-l to mg ml-1 in the legend of Figure l;see corrected Figure 1 below. (Figure Presented).(undefined
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