498 research outputs found
Células C em bócio colóide
PURPOSE: The aim of this investigation was to quantitatively evaluate C-cells in colloid goiters, analyzing 36 thyroids that were obtained through thyroidectomy from 24 patients with goiter and 12 normal glands from adult patients without thyroid disease, which were used as the control group. MATERIAL AND METHODS: On average, 6 different thyroid areas were sampled and labeled by immunohistochemistry with a monoclonal anticalcitonin antibody, utilizing the avidin-biotin-peroxidase complex. C-cells were counted in fields measuring 1 square centimeter, and the mean number of cells per field was then calculated. Data were statistically analyzed using the Mann-Whitney test. RESULTS: In the colloid goiter group, the number of C-cells ranged from 0 to 23 per field, while in normal controls they ranged from 20 to 148 per field. CONCLUSIONS: These results demonstrate a significant decrease of C-cell number in the colloid goiter group compared with control group, indicating that the hyperplastic process is restricted to follicular cells, to the detriment of C-cells, which probably cease to receive trophic stimuli.OBJETIVO: Pesquisar, quantitativamente, as células C em bócio colóide com o propósito de investigar a relação destas células na patogênese do bócio. MÉTODO: Foram analisadas 35 tiróides obtidas de tiroidectomia, sendo 24 de pacientes com bócio colóide e 11 tiróides normais de adulto usadas como controle. Seis diferentes áreas foram amostradas em média e coradas com o anticorpo monoclonal anticalcitonina. As células C foram contadas em campos de 1 cm² e o número médio de células/campo foi calculado. Os dados foram estudados estatisticamente pelo teste de Kruskal-Wallis. RESULTADOS: O número de células C variou de 0 a 23/cm² em bócio colóide e em tiróides normais de 20 a 148/cm². CONCLUSÕES: Os resultados demonstraram redução significativa no número de células C em bócio colóide comparando com tiróides normais, indicando que o processo hiperplásico é restrito às células foliculares em detrimento das células C, as quais, provavelmente, deixam de receber estímulos tróficos e se degeneram
The development of an excellence model integrating the Shingo model and sustainability
Companies are continuously looking to improve their production systems using excellence models, with lean thinking, the Shingo model, six sigma and lean six sigma being the most comprehensive and applied. It is expected that the initial focus for the survival of companies is their economic profitability, but when economic needs are met, the next step is to achieve operational excellence. For this, in addition to economic objectives, it is necessary to include social and environmental objectives, i.e., the other two pillars of sustainability. This study aims to propose a conceptual model identifying the tools that can help achieve the desired results in the three pillars of sustainability aligned with operational excellence. The design of the conceptual model was based on a bibliometric analysis of the literature that relates the concepts of lean thinking, six sigma, lean six sigma and the Shingo model. The Web of Science was the platform selected for the collection of data, and the timeframe considered was 2010 to 2021. A total of 125 articles were analyzed using the VosViewer software, through which it was possible to analyze different topics of study related to the literature. The bibliometric analysis allowed for the identification of the temporal distribution of publications, the categorization of topics, different areas of application and the importance of the tools used in different practical cases. This study points out that companies have at their disposal several tools to achieve economic objectives. On the other hand, there is a set of more restricted tools that are used to meet the objectives of the social and environmental pillars. Future research should focus on identifying tools that meet social and environmental goals in order to strengthen these pillars that are essential for operational excellence and for the sustainability of companies.The work of the author Vanda Lima is supported by national funds, through the FCT-Portuguese Foundation for Science and Technology under the project UIDB/04728/2020
Influência do agente precipitante na preparação do óxido de nióbio (V) hidratado pelo método da precipitação em solução homogênea
Chemical composition, antioxidant and antimicrobial activity of phenolic compounds extracted from wine industry by-products
Winery by-products are a rich source of polyphenols, which have proven to have several beneficial biological
properties, such as, antioxidant and antimicrobial activities. Therefore, this study aimed the extraction of
polyphenols from winery by-products of two Portuguese red grape varieties, Touriga Nacional and Preto
Martinho, and evaluate their phenolic profile, antioxidant properties and antimicrobial activity against antibiotic
resistant bacteria. The polyphenols were extracted from the grapes' skins, seeds and stems. Extracts were
analysed for total phenolic, anthocyanin and tannin contents, and the polyphenol profile was determined by
High Performance Liquid Chromatography. The antioxidant activity of the extracts was determined by ABTS+
and DPPH methods. Antimicrobial susceptibility assay was performed using Kirby-Bauer disc diffusion method.
Preto Martinho variety presented a higher polyphenolic content than Touriga Nacional. Malvidin 3-O-glucoside
was the most abundant compound found in the skins extracts in both varieties. The main phenolic compound
found in the seeds and stems extracts was catechin. From the several flavonols quantified, rutin was the most
abundant. For both varieties, the seeds extracts showed the highest antioxidant and antimicrobial properties,
followed by the stems extracts. The extracts showed antibacterial activity against all tested strains except on
gram-negative bacteria Salmonella enteritidis, Escherichia coli and Pseudomonas aeruginosa. These results show
that, natural products, such as polyphenols, may represent a source for the development of novel antimicrobials
to combat gram-positive resistant bacteria and possibly be used as natural food preservatives. However, they
were not effective against gram-negative resistant bacteria which shows that polyphenols, alone, might not
substitute antibiotics.info:eu-repo/semantics/publishedVersio
Modelling anaerobic digestion of sewage sludge: mechanistic models vs machine learning
Anaerobic digestion processes are one of the technologies most used by wastewater treatment plants (WWTPs) to stabilize and decrease the organic content of sludge. This process decreases the costs of disposal while increasing the energetic efficiency of WWTPs. In order to optimize this process, three model approaches were implemented. First, we calibrated and validated the anaerobic digestion model no.1 (ADM1) using data from an anaerobic lab digester treating sewage sludge (Phases I, II, III), and further receiving glycerol pulses (Phases IV, V). Then, to optimize the calibration and parameter estimation, an iterative procedure was applied by minimizing the root mean square error (RMSE). The second approach consisted of applying a machine learning (ML) model to the biogas and methane produced. The results showed that the ADM1 model adjusted well to the experimental results, especially to biogas, methane and pH. The optimization routine was useful to identify the most sensitive parameters, improving model calibration. Overall, the ML approach was more reliable to predict anaerobic reactors performance but did not respond so well to process perturbations (glycerol pulses).This work was supported by the Portuguese Foundation for
Science and Technology (FCT) under the scope of the strategic funding of
UIDB/04469/2020 and UIDB/00319/2020 units and the PAMWater Project
(DSAIPA/Al/0099/2019).info:eu-repo/semantics/publishedVersio
The Universal Cut Function and Type II Metrics
In analogy with classical electromagnetic theory, where one determines the
total charge and both electric and magnetic multipole moments of a source from
certain surface integrals of the asymptotic (or far) fields, it has been known
for many years - from the work of Hermann Bondi - that energy and momentum of
gravitational sources could be determined by similar integrals of the
asymptotic Weyl tensor. Recently we observed that there were certain overlooked
structures, {defined at future null infinity,} that allowed one to determine
(or define) further properties of both electromagnetic and gravitating sources.
These structures, families of {complex} `slices' or `cuts' of Penrose's null
infinity, are referred to as Universal Cut Functions, (UCF). In particular, one
can define from these structures a (complex) center of mass (and center of
charge) and its equations of motion - with rather surprising consequences. It
appears as if these asymptotic structures contain in their imaginary part, a
well defined total spin-angular momentum of the source. We apply these ideas to
the type II algebraically special metrics, both twisting and twist-free.Comment: 32 page
COMPOSTAGEM UMA OPÇÃO DE RENDA PARA A PEQUENA PROPRIEDADE RURAL: agregando valor aos resíduos sólidos orgânicos
Os resíduos orgânicos de origem urbana em grande parte são formados por restos de vegetais, resíduos domésticos ou descartes da cadeia de produção de alimentos
Shelf morphology as an indicator of sedimentary regimes: a synthesis from a mixed siliciclastic-carbonate shelf on the eastern Brazilian margin
Modern shelf morphology is the result of the interplay between short and long term sedimentary processes. The relation between rates of sediment supply/carbonate growth and accommodation space creation will not only control coastal transgression and regression, but will also define the shelf sedimentary regimes acting to shape the seabed. Herein, shelf morphology and sedimentology are investigated in order to discuss how these characteristics can be representative of distinct sedimentary regimes. The study area is the eastern Brazilian shelf where coastal transgression and regression coexist with the most important coral reef system of the South Atlantic. A compilation of existing published and unpublished data was carried out in order to produce morphological and faciological maps and compare the mapped features with high-resolution seismic and sonographic data. The results show three major regions or morphological compartments: Abrolhos Shelf, Doce River Shelf and the Paleovalleys Shelf. In terms of shelf sedimentary domain, rhodolith beds predominate over the outer shelf along the entire area, coralline reefs are present along the northern Abrolhos inner shelf and a significant terrigenous mud deposit is observed associated to the Doce River adjacent inner shelf beds. The rest of the shelf is composed by bioclastic or terrigenous mud sand and gravel. Terrigenous sedimentation is always restricted to the shoreface or inner shelf shallower areas and carbonate sands and gravels are predominant elsewhere. The Abrolhos shelf shows two distinct sectors; the northern area is a typical mixed sediment environment that has a supply regime along the coast/shoreface, mainly due to longshore transport and a carbonate regime along the inner and outer shelf. The southern shelf morphology and sedimentation are controlled by the antecedent topography and is typically a accommodation regime shelf with associated rhodolith beds. The Doce river shelf is a supply regime environment with the formation of a 5 to 8m thick regressive deposit with downlapping clinoforms. Southward from the Doce river shelf, a significant shift in sedimentary regime is observed as the morphology becomes very irregular with associated hardbottoms and unfilled paleovalleys. This sector of the shelf (Paleovalley shelf) is characterized by an accommodation regime. The interpretation shows that the entire study area can be defined as a mixed sedimentation shelf, showing supply and accommodation regimes. Shelf morphology worked as an indicator of these changes. Carbonate/terrigenous deposition during a highstand/regressive phase coeval along the eastern Brazilian shelf, either laterally and across shelf. This lateral/along coast variation in sediment supply and carbonate production leads to distinct lateral facies and geometry. These spatial changes in morphology and facies, with coexistence of carbonate and siliciclastic sedimentation, are very important for the correlation and interpretation of the geological record, especially stratigraphic surfaces and sequence units
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