47 research outputs found

    Study of The Influence of Bulk Properties and Surface Tension on the Deposition Process of Calcium Phosphate on Modified Stainless Steel

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    In order to reduce the fouling caused by milk during heat treatment, it is important to know more about the deposition process of calcium phosphate, one of the main components of milk fouling, on stainless steel surfaces. The fouling behaviour of calcium phosphate is controlled by several factors related to both the fouling solution properties and the surface characteristics. The present work is focused on the influence of two of these factors: 1) the size and size distribution of the calcium phosphate aggregates formed in solution upon heating and 2) the surface tension values of the deposition surface. It was possible to conclude that maximum deposit build up occurs at the temperature corresponding to the formation, in the bulk, of amorphous sphere-like calcium phosphate particles of about 0.1mm diameter and considering the surface effect, the maximum deposition is obtained on those surfaces having higher surface tension values

    Doença de Crohn vulvoperineal responsiva ao metronidazole

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    Crohn's disease is a multisystem chronic granulomatous inflammatory disease that primarily affects the gastrointestinal tract. In the majority of the cases, the cutaneous manifestations follow the intestinal disease, but occasionally dermatological lesions are the inaugural event and may constitute the only sign of the disease. Vulvoperineal involvement is rare, may precede bowel symptoms by months to years and may go unrecognized. Due to the paucity of reports of Crohn's disease at this location and in the absence of randomized trials, there are no standard treatments for the cutaneous disease. We describe the case of a 47 year-old woman with vulvoperineal Crohn's disease without digestive involvement, that was successfully managed with metronidazole

    FLOW CELL STUDIES ON FOULING CAUSED BY PROTEIN -CALCIUM PHOSPHATE DEPOSITION IN TURBULENT FLOW

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    A comparative study of the calcium phosphate fouling process, with and without proteins, was carried out using both standard 316 2R stainless steel and 2R surfaces modified by TiN magnetron sputtering. Fouling behavior was assessed in a heat transfer flow cell operating in the turbulent flow regime. The fouling curves resulting from calcium phosphate deposition in the absence of proteins were substantially different from the ones obtained when protein was present. In this last case, two different fouling periods could be observed. The surface energy of the modified materials was found to affect the deposition parameters (rate of deposition and final amount of deposit) leading to higher amounts of deposit on higher energy surfaces in the absence of protein, while leading to less deposit in its presence. The standard 316 2R substrate proved to be less prone to fouling from protein-calcium phosphate solutions than the TiN modified surfaces. However, the same conclusion could not be drawn for calcium phosphate solutions

    SIMULATION OF CALCIUM PHOSPHATE DEPOSITION ON STAINLESS STEEL SURFACES: A NEW APPROACH BASED ON CELLULAR AUTOMATA

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    Fouling caused by calcium phosphate upon heating is basically a crystallization/precipitation process, which starts with the formation of stable clusters of ions or molecules in a process called nucleation that occurs either in the bulk liquid or at the surface. The cellular automata are useful tools to model complex systems of the universe. They could be considered as a good alternative to differential equations and have been used to model many physical/biological systems. In this preliminary work, a two dimensional space was considered where the cellular automata lattice was represented as a grid of squares, with each square representing a single automaton cell. Several situations were simulated, representing the growth of the deposit on stainless steel materials for different surface energies. The results of the simulations were compared with experimental data obtained in the laboratory

    Tumors of skin appendages – A 10-year review

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    Introdução: Os tumores dos anexos cutâneos representam um grupo heterogéneo de neoplasias benignas e malignas com diferentes diferenciações morfológicas. Material e Métodos: Foi efectuado o estudo retrospectivo dos tumores dos anexos cutâneos diagnosticados na consulta externa do Serviço de Dermatologia do Centro Hospitalar do Porto, EPE-HSA entre 2000 a 2009. Resultados: Foram diagnosticados 404 tumores dos anexos cutâneos. Apenas 3% dos tumores eram malignos. A maioria apresentou uma diferenciação (62,6 %) folicular. Discussão: A revisão da literatura mostrou uma escassez de dados relativos a estudos retrospectivos dos tumores dos anexos cutâneos. Mais estudos são necessários para uma melhor caracterização epidemiológica destas entidades

    L-asparaginase recovery through supported ionic liquid materials based on silica

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    Acute lymphoblastic leukemia (ALL) accounts with approximately 6500 new cases in the United States each year [1]. The first-line biopharmaceutical being used to treat ALL, Oncaspar, is based on L-asparaginase (LA), with annual sales of approximately USD $100 million [2]. The main problem related to the therapeutic use of LA is the difficulty in its purification, accounting for up to 80% of total production costs [3]. Therefore, it is crucial to find new strategies to purify LA in order to decrease its current cost and allow its routinely use by a widespread population. Supported ionic liquid materials based on silica (SILs) are reported in the literature for the separation of natural compounds from vegetable biomass [4]. Although SILs represent a class of materials with high potential in protein purification, this specific application has been scarcely considered [5]. In this work, the search for SILs able to establish (non-covalent) specific interactions with LA, which subsequently allow its purification from the fermentation broth in which it is produced, was studied. In a first set of experiments, commercial LA was used in order to understand the adsorption behaviour of the enzyme onto SILs. Experimental conditions, such as pH, contact time and SILs/LA ratio were evaluated and optimized in what concerns the LA recovery yield. LA activity was assessed by the Nessler reaction, which quantifies the amount of ammonium released after the enzymatic reaction [6]. The results show that the ideal conditions for LA are pH 8 and a contact time with SILs of 30 min. With the envisioned strategy, process costs, energy consumed, and waste generated, can be considerably reduced, which can lead to the LA cost decrease and wider application. Further investigations on the purification of LA from the fermentation broth are ongoing.publishe

    Monozygotic twins concordant for common variable immunodeficiency : strikingly similar clinical and immune profile associated with a polygenic burden

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    Copyright © 2019 Silva, Fonseca, Pereira, Silva, Barbosa, Serra-Caetano, Blanco, Rosmaninho, Pérez-Andrés, Sousa, Raposo, Gama-Carvalho, Victorino, Hammarstrom and Sousa. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Monozygotic twins provide a unique opportunity to better understand complex genetic diseases and the relative contribution of heritable factors in shaping the immune system throughout life. Common Variable Immunodeficiency Disorders (CVID) are primary antibody defects displaying wide phenotypic and genetic heterogeneity, with monogenic transmission accounting for only a minority of the cases. Here, we report a pair of monozygotic twins concordant for CVID without a family history of primary immunodeficiency. They featured a remarkably similar profile of clinical manifestations and immunological alterations at diagnosis (established at age 37) and along the subsequent 15 years of follow-up. Interestingly, whole-exome sequencing failed to identify a monogenic cause for CVID, but unraveled a combination of heterozygous variants, with a predicted deleterious impact. These variants were found in genes involved in relevant immunological pathways, such as JUN, PTPRC, TLR1, ICAM1, and JAK3. The potential for combinatorial effects translating into the observed disease phenotype is inferred from their roles in immune pathways, namely in T and B cell activation. The combination of these genetic variants is also likely to impose a significant constraint on environmental influences, resulting in a similar immunological phenotype in both twins, despite exposure to different living conditions. Overall, these cases stress the importance of integrating NGS data with clinical and immunological phenotypes at the single-cell level, as provided by multi-dimensional flow-cytometry, in order to understand the complex genetic landscape underlying the vast majority of patients with CVID, as well as those with other immunodeficiencies.This work received funding from PAC - PRECISE - LISBOA-01-0145-FEDER-016394, co-funded by FEDER through POR Lisboa 2020 - Programa Operacional Regional de Lisboa PORTUGAL 2020 and Fundação para a Ciência e a Tecnologia; and UID/BIM/50005/2019, project funded by Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e Ensino Superior (MCTES) through Fundos do Orçamento de Estado. Work in MG-C lab is supported by UID/MULTI/04046/2019 Research Unit grant from FCT, Portugal (to BioISI) and FCT research grant PTDC/BIA-CEL/29257/2017.info:eu-repo/semantics/publishedVersio
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