342 research outputs found
Effect of chitosan and Aloe Vera extract concentrations on the physicochemical properties of chitosan biofilms
Chitosan films have been extensively studied as dressings in formulations for the treatment of chronic wounds. The incorporation of aloe vera (Aloe barbadensis Miller) into chitosan dressings could potentialize the healing process since aloe vera shows several pharmacological activities. This work aimed to evaluate the effect of aloe vera and chitosan concentrations on the physicochemical properties of the developed films. The films were obtained by casting technique and characterized with respect to their color parameters, morphology, barrier and mechanical properties, and thermal analysis. Results showed that the presence of aloe vera modified the films color parameters, changed barrier properties, increased fluid handling capacity (FHC), and decreased water-vapor permeability (WVP). The reduced elongation at break resulted in more rigid films. Aloe vera concentration did not significantly change film properties, but the presence of this gel increased the films stability at temperatures below 200 °C, showing similar behavior as chitosan films above 400 °C. The results suggest a crosslinking/complexation between chitosan and aloe vera, which combine appropriate physicochemical properties for application as wound dressing materials.This work was supported by São Paulo Research Foundation (FAPESP) (2010/17.721-4), Portuguese Science and Technology Foundation (FCT) through the projects M-ERA-NET/0004/2015 (PAIRED) and UIDB/04469/2020 (strategic fund) funded by national funds, and co-financed Education (FCT/MEC) from national funds and FEDER, under the Partnership Agreement PT202info:eu-repo/semantics/publishedVersio
Street food in Maputo, Mozambique: The coexistence of minimally processed and ultra-processed foods in a country under nutrition transition
The aim was to characterise the extent of processing and nutritional composition of the street foods offered in Maputo, Mozambique. A cross-sectional study was conducted in October November 2014 in the urban district of KaMpfumu. Twenty public transport stops were randomly selected, around which 500 meters buffers were drawn. All streets within these buffers were can-vassed to identify all street food vending sites. Street food offer was assessed through interviews. Nutritional composition was estimated using standardised recipes (for homemade foods), food labels (for industrial products) and food composition tables (for in natura foods). The processing extent was classified using the NOVA food classification. A total of 810 vending sites were assessed. Unprocessed/minimally processed foods were available at 70.5% of vending sites (mainly fruit, water, and tea) and ultra-processed foods at 59.0% (mostly cakes, cookies, confectionery, and soft drinks). Energy content per 100 g of unprocessed or minimally processed foods was significantly lower than in all other food groups. In all food groups, contribution to total energy value was highest for carbohydrates (range: 33.151.2%), followed by fats (range: 29.336.0%) and protein (range: 6.818.6%). Public health policies targeting the improvement of this urban food environment should consider not only the nutritional composition but also the processing extent of the foods and beverages available. (c) 2021 by the authors. Licensee MDPI, Basel, Switzerland
Molybdenum(VI) complexes with ligands derived from 5-(2-pyridyl)-2H-tetrazole as catalysts for the epoxidation of olefins
The development of effective catalytic epoxidation processes that are an alternative to stoichiometric non-selective oxidation routes is important to meet environmental sustainability goals. In this work, molybdenum (VI) compounds bearing 5-(2-pyridyl)-2H-tetrazole derivatives as organic components, namely the ionic and neutral mononuclear complexes (H2ptz)[MoO2Cl2(ptz)] (1) and [MoO2Cl2(tBu-ptz)] (2), and the new Lindqvist-type polyoxometalate (POM) [tBu-Hptz]2[Mo6O19] (3), where Hptz = 5-(2-pyridyl)tetrazole and tBu-ptz = 2-tert- butyl-5-(2-pyridyl)- 2H-tetrazole, were studied as epoxidation catalysts using readily available and relatively ecofriendly hydroperoxide oxidants, namely hydrogen peroxide and tert-butyl hydroperoxide (TBHP). The pre-pared catalysts were very active. For example, 100% cis-cyclooctene conversion and 100% epoxide selectivity were reached at 1 h for 1 and 3, and 10 min for 2 (with TBHP). Catalytic and characterization studies indicated that the mononuclear complexes suffered chemical transformations under the reaction conditions, whereas 3 was structurally stable. This POM acted as a homogeneous catalyst and could be recycled by employing an ionic liquid solvent. The POM can be synthesized from 2 under different conditions, including those used in the catalytic process. Moreover, 3 was an effective epoxidation catalyst for a biobased substrate scope that included fatty acid methyl esters and the terpene dl-limonene.POCI-01-0145-FEDER-030075; LA/P/0006/2020; EMBRC.PT ALG-01–0145-FEDER-022121; (grant ref. 2021.06403.BDinfo:eu-repo/semantics/publishedVersio
Reliability of manual segmentation of cornea, contact lens and tear film using a high-resolution OCT
In this study, we aimed to evaluate the intra/inter-session and intra/inter-observer variability of manual segmentation of
thickness of the pre-lens tear film, contact lens (CL), post-lens tear film, epithelium, bowman’s layer, stroma and the
whole cornea and CLs with a flat and a steep fit, using a commercial high-resolution spectral domain optical coherence
tomographer (OCT). Two different observers obtained three repeated measures in two separate sessions. A high
correlation was found between the values obtained by the two different observers, except for the thinner layers,
epithelium, and Bowman’s layer. Inter-observer analysis showed a high consistency in the measurements obtained by
both observers (r
2 ≥ 0.80; p < 0.001) for the thicker layers: CL, stroma, and total cornea. Intra-observer analysis of
measurements obtained by each observer within the same session displayed no statistically significant differences
between the three repeated measures for both observers (p > 0.05). The present results suggest that manual segmentation
of anterior segment OCT images in CL wearers provides acceptable levels of repeatability between observers and
between different sessions for the thinner layers, while presenting a high level of repeatability for the thicker layers.This work was supported by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project PEST-C/FIS/UI607/2011. Supported in part by research grants to A. Cervino from the Universitat de Valencia (UV-AE-20070225), the "Jose Castillejo" Research Grant from the Spanish Ministry of Science and Technology (JC2008-00078) and the Spanish Network for Research in Optometry (SAF2008-01114-E)
Impact of allergic rhinitis and specific subcutaneous immunotherapy on peripheral blood basophils of patients sensitized to Dermatophagoides pteronyssinus
BACKGROUND: Basophils are important effectors cells in allergic rhinitis (AR) since they are involved in immunoglobulin (Ig) E – mediated inflammation and in the release of pro-inflammatory mediators. Specific subcutaneous immunotherapy (SCIT) provides clear immunologic modulation in some immune cells, however its systemic effects on basophils are not well known. METHODS: Peripheral blood (PB) samples from 43 patients with allergic rhinitis mono-sensitized to Dermatophagoides pteronyssinus (Dpt) [33 of them under SCIT with allergoid Dpt extract, in maintenance dose (SCIT), with evaluation just before SCIT injection (SCIT-T0) and 4 hours later (SCIT-T4) and the other 10 Dpt allergic patients never having, in the past, undergone specific immunotherapy treatment (NSIT)], and 15 healthy age- and gender-matched controls (HG), were analyzed. For each sample, the total (t-IgE) and specific IgE (s-IgE) was performed, as well as, the relative frequency and absolute number of PB basophils and receptor-bound IgE and IgG expression were evaluated by flow cytometry and the Histamine N-methyltransferase (HNMT) and tryptase α/β1 (TPSAB1) gene expression was assessed by real-time PCR. RESULTS: Higher levels of receptor-bound IgE were observed in SCIT patients, which are correlated with the levels of serum t-IgE and s-IgE, whereas no significant differences were observed for receptor-bound IgG. Regarding HNMT mRNA expression, significantly lower expression levels were detected in AR patients compared to HG, independently of type of therapy. Moreover a negative correlation was found between HNMT gene expression and time under SCIT. Conversely, tryptase gene expression was significantly up-regulated in NSIT when compared to HG; however in SCIT patients, tryptase gene expression was significantly decreased than in NSIT patients. No differences were found for any parameter between SCIT-T0 and SCIT-T4 with exception of a transient increased expression of tryptase in SCIT-T4. CONCLUSION: PB basophils from patients with AR show altered functional features, which seems to be influenced by SCIT, suggesting that these cells could be useful to clarify the SCIT triggered mechanisms at a systemic level
A Molybdenum(VI) Complex of 5-(2-pyridyl-1-oxide)tetrazole: synthesis, structure, and transformation into a MoO3-Based hybrid catalyst for the epoxidation of Bio-Olefins
The discovery of heterogeneous catalysts synthesized in easy, sustainable ways for the
valorization of olefins derived from renewable biomass is attractive from environmental, sustainability, and economic viewpoints. Here, an organic–inorganic hybrid catalyst formulated as
[MoO3
(Hpto)]·H2O (2), where Hpto = 5-(2-pyridyl-1-oxide)tetrazole, was prepared by a hydrolysis–
condensation reaction of the complex [MoO2Cl2
(Hpto)]·THF (1). The characterization of 1 and 2
by FT-IR and Raman spectroscopies, as well as 13C solid-state NMR, suggests that the bidentate
N,O-coordination of Hpto in 1 (forming a six-membered chelate ring, confirmed by X-ray crystallography) is maintained in 2, with the ligand coordinated to a molybdenum oxide substructure.
Catalytic studies suggested that 2 is a rare case of a molybdenum oxide/organic hybrid that acts as a
stable solid catalyst for olefin epoxidation with tert-butyl hydroperoxide. The catalyst was effective
for converting biobased olefins, namely fatty acid methyl esters (methyl oleate, methyl linoleate,
methyl linolenate, and methyl ricinoleate) and the terpene limonene, leading predominantly to the
corresponding epoxide products with yields in the range of 85–100% after 24 h at 70 ◦C. The versatility
of catalyst 2 was shown by its effectiveness for the oxidation of sulfides into sulfoxides and sulfones,
at 35 ◦C (quantitative yield of sulfoxide plus sulfone, at 24 h; sulfone yields in the range of 77–86%).
To the best of our knowledge, 2 is the first molybdenum catalyst reported for methyl linolenate
epoxidation, and the first of the family [MoO3
(L)x] studied for methyl ricinoleate epoxidation.LA/P/0006/2020; POCI-01-0145-FEDER-030075; ALG-01-0145-FEDER-022121; grant ref. 2021.06403.BD; grant ref. 2021.04756.BD;info:eu-repo/semantics/publishedVersio
Seleção de avaliações adaptativas em sistemas gerenciadores de aprendizagem utilizando mineração de dados
A avaliação da aprendizagem é um dos aspectos mais relevantes e controversos no ensino presencial e esta dificuldade parece ter se transferido para os Sistemas Gerenciadores de Aprendizagem. Na grande maioria desses ambientes todos os estudantes são avaliados de maneira uniforme independente do seu nÃvel de aquisição de conhecimentos e dos conteúdos abordados. O insucesso recorrente nessas avaliações pode ser desestimulante para o aprendiz e torna o processo de avaliação ineficaz uma vez que os resultados não são utilizados para realimentar o próprio processo de avaliação. Este artigo tem por objetivo apresentar um modelo para a seleção de avaliações adaptativas num ambiente computacional de aprendizagem utilizando técnicas de mineração de dados com base no nÃvel de aquisição de conhecimentos do estudante em cada item do domÃnio em questão e também nos conteúdos abordados nas unidades de Avaliação.Facultad de Informátic
Riggia cryptocularis (Crustacea: Cymothoidae) parasitizing three fish species in a hydroelectric dam
Introduction: Parasites play important roles in ecosystems, but can also create disturbances in the composition of host fauna in anthropogenic environments. Objective: Knowledge about these organisms can contribute to the conservation of diversity and environmental quality and prediction of disease risks. Methods: Parasites were collected from fish hosts in the Doce River (Claro River Basin, Middle ParanaÃba) in areas of a small hydropower plant, following specific protocol and identified in the laboratory. Results: This is the first report of Riggia cryptocularis (Crustacea: Cymothoidae) parasitizing Hypostomus ancistroides, Leporinus friderici and Serrasalmus maculatus. Conclusion: The presence of this parasite in three fish species during the same sampling period and the severity of mutilation in the host suggest that the dam may favor a possible outbreak of the parasite R. cryptocularis due to changes introduced in the environment by the establishment of this type of project
Root causes and outcomes of postoperative pulmonary complications after abdominal surgery: A retrospective observational cohort study
FCT project IPOscore (DSAIPA/DS/0042/2018).Background: Postoperative pulmonary complications (PPCs) contribute significantly to overall postoperative morbidity and mortality. In abdominal surgery, PPCs remain frequent. The study aimed to analyze the profile and outcomes of PPCs in patients submitted to abdominal surgery and admitted in a Portuguese polyvalent intensive care unit. Methods: From January to December 2017 in the polyvalent intensive care unit of Hospital Garcia de Orta, Almada, Portugal, we conducted a retrospective, observational study of inpatients submitted to urgent or elective abdominal surgery who had severe PPCs. We evaluated the perioperative risk factors and associated mortality. Logistic regression was performed to find which perioperative risk factors were most important in the occurrence of PPCs. Results: Sixty patients (75% male) with a median age of 64.5 [47-81] years who were submitted to urgent or elective abdominal surgery were included in the analysis. Thirty-six patients (60%) developed PPCs within 48 h and twenty-four developed PPCs after 48 h. Pneumonia was the most frequent PPC in this sample. In this cohort, 48 patients developed acute respiratory failure and needed mechanical ventilation. In the emergency setting, peritonitis had the highest rate of PPCs. Electively operated patients who developed PPCs were mostly carriers of digestive malignancies. Thirty-day mortality was 21.7%. The risk of PPCs development in the first 48 h was related to the need for neuromuscular blocking drugs several times during surgery and preoperative abnormal arterial blood gases. Median abdominal surgical incision, long surgery duration, and high body mass index were associated with PPCs that occurred more than 48 h after surgery. The American Society of Anesthesiologists physical status score 4 and COPD/Asthma determined less mechanical ventilation needs since they were preoperatively optimized. Malnutrition (low albumin) before surgery was associated with 30-day mortality. Conclusion: PPCs after abdominal surgery are still a major problem since they have profound effects on outcomes. Our results suggest that programs before surgery, involve preoperative lifestyle changes, such as nutritional supplementation, exercise, stress reduction, and smoking cessation, were an effective strategy in mitigating postoperative complications by decreasing mortality.publishersversionpublishe
Um modelo para seleção de avaliações adaptativas em ambientes computacionais de aprendizagem
No sistema tradicional de ensino e também na grande maioria dos Ambientes Computacionais de Aprendizagem todos os estudantes são avaliados de maneira uniforme independente do seu nÃvel de aquisição de conhecimentos e dos conteúdos abordados. O insucesso recorrente nessas avaliações pode ser desestimulante para o aprendiz e torna o processo de avaliação formativa ineficaz uma vez que os resultados não são utilizados para realimentar o próprio processo de avaliação. Este artigo tem por objetivo apresentar um modelo para a seleção de avaliações adaptativas num ambiente computacional de aprendizagem utilizando técnicas de mineração de dados com base no nÃvel de aquisição de conhecimentos do estudante em cada item do domÃnio em questão e também nos conteúdos abordados nas unidades de Avaliação. A seleção de unidades de avaliação adequadas ao perfil atual do estudante criará condições para avaliações personalizadas de modo a proteger ou desafiar o aprendiz nos seus sucessos ou insucessos.In the traditional system of education and also in the great majority of Computational Environments of Learning all the students are evaluated in an independent uniform way it its level of acquisition of knowledge and them boarded contents. The recurrent failure in these evaluations can be discouraged for the apprentice and becomes the process of inefficacious formative evaluation once that the results are not used to feedback the proper process of evaluation. This article has for objective to present a model for the selection of adaptive evaluations in a computational environment of learning using data mining techniques based on the level of acquisition of knowledge of the student in each item of the domain in question and also in the boarded contents in the units of the Evaluation. The selection of adequate units of evaluation to the current profile of the student will create conditions for personalized evaluations in order to protect or to defy the apprentice in its successes or failures.VI Workshop de TecnologÃa Informática Aplicada en EducaciónRed de Universidades con Carreras en Informática (RedUNCI
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