371 research outputs found

    Palladium-catalyzed borylation and Suzuki coupling (BSC) to obtain beta-substituted dehydroamino acid derivatives

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    Several benzo[b]thienyldehydroamino acids were prepared by one pot palladium-catalyzed borylation and Suzuki coupling (BSC) from bromobenzo[b]thiophenes containing EDG (OMe or Me), as the component to be borylated with pinacolborane, and pure stereoisomers of beta-bromodehydroamino acid derivatives. To our knowledge it is the first time that the BSC reaction involves a non aromatic system.Fundação para a Ciência e Tecnologia - POCTI/1999/QUI/32689, SFRH/BD/4709/2001

    Immunopathogenesis in Trypanosoma cruzi infection: a role for suppressed macrophages and apoptotic cells

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    During Trypanosoma cruzi infection, macrophages phagocytose parasites and remove apoptotic cells through efferocytosis. While macrophage 1 (M1) produces proinflammatory cytokines and NO and fights infection, M2 macrophages are permissive host cells that express arginase 1 and play a role in tissue repair. The regulation of M1 and M2 phenotypes might either induce or impair macrophage-mediated immunity towards parasite control or persistence in chronic Chagas disease. Here, we highlight a key role of macrophage activation in early immune responses to T. cruzi that prevent escalating parasitemia, heart parasitism, and mortality during acute infection. We will discuss the mechanisms of macrophage activation and deactivation, such as T cell cytokines and efferocytosis, and how to improve macrophage-mediated immunity to prevent parasite persistence, inflammation, and the development of chagasic cardiomyopathy. Potential vaccines or therapy must enhance early T cell-macrophage crosstalk and parasite control to restrain the pathogenic outcomes of parasite-induced inflammation in the heart

    Leadership and management in the schools of the Autonomous Region of Madeira: A case study

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    Este estudo de investigação, de caracter misto, consistiu na aplicação de um inquérito a 504 professores e a realização de 19 entrevistas semiestruturadas (dezoito a Diretores/Presidentes das instituições escolares, e uma ao Diretor Regional da Administração Educativa). Foi nosso objetivo fazer uma análise sobre o tema da organização, gestão e liderança escolar dos Diretores/Presidentes das escolas do segundo e terceiros Ciclos do Ensino Básico e do Ensino Secundário da Região Autónoma da Madeira (RAM). Neste artigo iremos focar-nos nos resultados qualitativos resultantes da investigação. Os resultados do estudo revelaram que: os professores continuam a preocupar-se com a transmissão dos valores fundamentais e alcance do sucesso educativo numa escola em crise; que o estilo de liderança predominantemente adotado pelos Diretores/Presidentes das escolas da RAM é o estilo transformacional; que o exercício do gestor/líder obedece a um perfil enquadrado num modelo de Diretor/Presidente padrão com caraterísticas bem determinadas.This research, mixed in nature, deals with the application of a questionnaire to 504 teachers and the performance of 19 semi structured interviews (18 to school Head teachers and one to the Regional Educational Administration Director). It was our objective to do an analysis on the subject of organization, school management and leadership of the Directors / Presidents of the second and third of the schools of basic education cycles and Secondary Education of the Autonomous Region of Madeira (RAM). In this article we will focus on the qualitative results derived from the research study. The results of this study reveal that: the teachers are still worrying about the transmission of fundamental values and the reach of the educational success within a school in crisis; the predominant style of leadership adopted by Head teachers in RAM is the “transformational” style; the manager/leader performance follows a pattern of well-defined characteristics.info:eu-repo/semantics/publishedVersio

    Coupling of Cyclic Voltammetry and Electrochemical Impedance Spectroscopy for Probing the Thermodynamics of Facilitated Ion Transfer Reactions Exhibiting Chemical Kinetic Hindrances

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    Mathematical models under conditions of cyclic staircase voltammetry and electrochemical impedance spectroscopy (EIS), which consider the kinetic effects due to the complexation reaction by the facilitated transfer of metal ions at polarized interfaces, are presented. Criteria for qualitative recognition of these kinetic effects from the features of simulated cyclic voltammograms are given. In case of the existence of these effects, only the EIS can bring access to the thermodynamics and kinetics of the complexation chemical reaction. Analytical equations for estimating the thermodynamic parameters by such systems under EIS conditions are evaluated. The theoretical results are compared with the experimental results of the facilitated Cu2+ transfer at the polarized water-1,2-dichlorethane interface, assisted by two phenanthroline-containing macrocycles. In the experimental case where kinetic effects due to the complexation step exist, we show how elegantly EIS can be used as a tool for estimation of the complexation constant of Cu2+ and 5-oxo-2,8-dithia [9],(2,9)-1,10-phenanthrolinophane (PhenOS2)

    Evaluation of phosphorus levels in bones and serum of buffaloes (Bubalus bubalis) before and after supplementation with a selective mineral mixture

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação Amazônia de Amparo a Estudos e Pesquisas do Estado do Pará (FAPESPA), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) – Finance Code 001, Programa de Pós-graduação em Reprodução Animal na Amazônia (ReproAmazon), Instituto de Medicina Veterinária (IMV) and to Pró Reitora de Pesquisa e Pós-Graduação of the Universidade Federal do Pará (PROPESP-UFPA), Programa de Apoio à Publicação Qualificada - edital PAPQ/2022Universidade Federal do Pará-Campus Castanhal. Instituto de Medicina Veterinária. Castanhal, PA, Brazil.Universidade Federal do Sul e Sudeste do Pará. Instituto de Estudos do Trópico Úmido. Xinguara, PA, Brazil.Universidade Federal do Pará-Campus Castanhal. Instituto de Medicina Veterinária. Castanhal, PA, Brazil.Universidade Federal do Pará-Campus Castanhal. Instituto de Medicina Veterinária. Castanhal, PA, Brazil.Ministério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Laboratório de Toxicologia. Ananindeua, PA, Brasil.Universidade Federal Rural da Amazônia. Instituto de Ciências Agrárias. Belém, PA, Brazil.Universidade Federal do Pará-Campus Castanhal. Instituto de Medicina Veterinária. Castanhal, PA, Brazil.Universidade Federal do Pará-Campus Castanhal. Instituto de Medicina Veterinária. Castanhal, PA, Brazil.This study aimed to evaluate phosphorus (P) concentration in serum and bone, the percentage of ash and the specific bone density of buffaloes on Ilha de Marajó before and after mineral supplementation. For this study, 14 crossbred buffaloes of Murrah and Mediterranean descent aged between 18 and 36 months were used. The average values of P before supplementation in serum and bone, the percentage of bone ash and the specific bone density were 5.68mg/dL±1.18, 16.53%±0.53, 59.95%±1.96 and 1.52g/cm3 ±0.32, respectively, which demonstrated P deficiency in animals raised on Ilha de Marajó. After supplementation with P for a period of seven months, the values were 6.61mg/dL±0.87, 16.90%±0.56 and 60.30%±0.95 and 1.71g/cm3 ±0.21, respectively. These results showed a significant increase in P concentration in blood serum, specific bone density and percentage of P in ash (P<0.05), but there was no significant increase in the percentage of ash. The average increase in P in the serum and ash did not reach normal levels in all animals; however, 28.6% of the animals had normal values of P in serum and 50% in the ash, and 64.3% had normal specific bone density values. The nonre-establishment, in some of the animals, of the variables of P serum and bone after supplementation for seven months may have occurred as a result of the low intake of the mineral mixture and by the low concentration of P in the Brachiaria brizantha cv. Marandu used for feeding animals during the experiment

    Sodium alginate/polycaprolactone co-axial wet-spun microfibers modified with N-carboxymethyl chitosan and the peptide AAPV for Staphylococcus aureus and human neutrophil elastase inhibition in potential chronic wound scenarios

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    In chronic wound (CW) scenarios, Staphylococcus aureus-induced infections are very prevalent. This leads to abnormal inflammatory processes, in which proteolytic enzymes, such as human neutrophil elastase (HNE), become highly expressed. Alanine-Alanine-Proline-Valine (AAPV) is an antimicrobial tetrapeptide capable of suppressing the HNE activity, restoring its expression to standard rates. Here, we proposed the incorporation of the peptide AAPV within an innovative co-axial drug delivery system, in which the peptide liberation was controlled by N-carboxymethyl chitosan (NCMC) solubilization, a pH-sensitive antimicrobial polymer effective against Staphylococcus aureus. The microfibers' core was composed of polycaprolactone (PCL), a mechanically resilient polymer, and AAPV, while the shell was made of the highly hydrated and absorbent sodium alginate (SA) and NCMC, responsive to neutral-basic pH (characteristic of CW). NCMC was loaded at twice its minimum bactericidal concentration (6.144 mg/mL) against S. aureus, while AAPV was loaded at its maximum inhibitory concentration against HNE (50 μg/mL), and the production of fibers with a core-shell structure, in which all components could be detected (directly or indirectly), was confirmed. Core-shell fibers were characterized as flexible and mechanically resilient, and structurally stable after 28-days of immersion in physiological-like environments. Time-kill kinetics evaluations revealed the effective action of NCMC against S. aureus, while elastase inhibitory activity examinations proved the ability of AAPV to reduce HNE levels. Cell biology testing confirmed the safety of the engineered fiber system for human tissue contact, with fibroblast-like cells and human keratinocytes maintaining their morphology while in contact with the produced fibers. Data confirmed the engineered drug delivery platform as potentially effective for applications in CW care.Authors acknowledge the Portuguese Foundation for Science and Technology (FCT), FEDER funds by means of Portugal 2020 Competitive Factors Operational Program (POCI) and the Portuguese Government (OE) for funding the project PEPTEX with reference PTDC/CTMTEX/28074/2017 (POCI-01-0145-FEDER-028074). Authors also acknowledge project UIDP/00264/2020 of 2C2T and UID/QUI/00686/2020 of CQ, funded by national funds through FCT/MCTES. C.S.M. and H.P.F. also acknowledge FCT for PhD funding via scholarship 2020.08547.BD and for auxiliary researcher contract via 2021.02720.CEEIND, respectively

    Bioactivity of chitosan-based particles loaded with plant-derived extracts for biomedical applications: emphasis on antimicrobial fiber-based systems

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    Marine-derived chitosan (CS) is a cationic polysaccharide widely studied for its bioactivity, which is mostly attached to its primary amine groups. CS is able to neutralize reactive oxygen species (ROS) from the microenvironments in which it is integrated, consequently reducing cell-induced oxidative stress. It also acts as a bacterial peripheral layer hindering nutrient intake and interacting with negatively charged outer cellular components, which lead to an increase in the cell permeability or to its lysis. Its biocompatibility, biodegradability, ease of processability (particularly in mild conditions), and chemical versatility has fueled CS study as a valuable matrix component of bioactive small-scaled organic drug-delivery systems, with current research also showcasing CS's potential within tridimensional sponges, hydrogels and sutures, blended films, nanofiber sheets and fabric coatings. On the other hand, renewable plant-derived extracts are here emphasized, given their potential as eco-friendly radical scavengers, microbicidal agents, or alternatives to antibiotics, considering that most of the latter have induced bacterial resistance because of excessive and/or inappropriate use. Loading them into small-scaled particles potentiates a strong and sustained bioactivity, and a controlled release, using lower doses of bioactive compounds. A pH-triggered release, dependent on CS's protonation/deprotonation of its amine groups, has been the most explored stimulus for that control. However, the use of CS derivatives, crosslinking agents, and/or additional stabilization processes is enabling slower release rates, following extract diffusion from the particle matrix, which can find major applicability in fiber-based systems within ROS-enriched microenvironments and/or spiked with microbes. Research on this is still in its infancy. Yet, the few published studies have already revealed that the composition, along with an adequate drug release rate, has an important role in controlling an existing infection, forming new tissue, and successfully closing a wound. A bioactive finishing of textiles has also been promoting high particle infiltration, superior washing durability, and biological response.FCT. Portuguese Foundation for Science and Technology (FCT), FEDER funds by means of Portugal 2020 Competitive Factors Operational Program (POCI) and the Portuguese Government (OE), grant number PTDC/CTMTEX/28074/2017 (POCI-01-0145- FEDER-028074). Authors also acknowledge project UID/CTM/00264/2021 of Centre for Textile Science and Technology (2C2T), funded by national funds through FCT/MCTES. J.D. and C.S.M. also acknowledge FCT for PhD grants 2020.07387.BD and 2020.08547.BD, respectivel

    Avaliação biomecânica dos trabalhadores em marcenarias no Distrito Federal.

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    The aim of this study was the biomechanical assessment of carpentry woodworkers, located in Brasília, DF. It was filmed the profile of each worker during the performance of his activities in the carpentry and the forces involved in the work were assessed. The image of each woodworker was congealed to accomplish the measurement of articulation angles. The data were submitted to the software of posture analysis “Winowas” (OWAS Method) and to the biomechanic model of posture prognosis and static forces, developed by Michigan University. The OWAS method showed that, for all machines and carpentries assessed, the worst posture occurred when the worker lifted and placed the pieces of wood on the floor and during the feeding in the smoother. The tridimensional biomechanic model registered the worst posture in different phases of the work cycle. In the first one, there were problems in all articulations, except the hips, when placing the pieces on the floor from the smoother. In the second one, there were problems in all articulations, except the elbows and the L5-S1 column disc, by feeding the surface planer. The third one, the ankles were the most injured when feeding the smoother, the surface planer, the circular saw and the band saw. According to the results, the woodworkers should try to eliminate the constant work standing upright, use auxiliary machinery to handle pieces of wood, reduce the load during feeding the machines and improve postures.A pesquisa foi desenvolvida com base em dados coletados com funcionários de marcenarias no Distrito Federal com o objetivo de fazer uma avaliação biomecânica do trabalhador nas mais diversas máquinas. A avaliação foi feita com a filmagem dos trabalhadores em perfil, avaliação das forças envolvidas e posterior congelamento das imagens e medição dos ângulos das articulações para análise no software "Winowas" de análise de posturas e no modelo biomecânico tridimensional de predição de posturas e forças estáticas desenvolvido pela Universidade de Michigan. Os resultados mostraram que, pelo método OWAS, as piores posturas foram obtidas durante o levantamento e deposição das peças no piso em todas as máquinas e postos de trabalho avaliados e durante a alimentação na desengrossadeira, necessitando de reorganização ergonômica em breve. Pela análise com o modelo desenvolvido pela Universidade de Michigan, as fases do ciclo de trabalho mais problemáticas foram a deposição das peças no piso na desengrossadeira quando houve o comprometimento de todas as articulações com exceção dos quadris. Durante a alimentação na desempenadeira, houve grande comprometimento das articulações com exceção dos cotovelos e do disco L5-S1 da coluna. Na fase de alimentação na desengrossadeira, desempenadeira, serra circular e serra de fita, as articulações mais prejudicadas foram os tornozelos. Para melhoria das posturas adotadas, deve-se buscar eliminar o constante trabalho em pé, utilizar mecanização auxiliar para manuseio das peças, diminuir o peso manuseado durante a alimentação das máquinas (menor número e tamanho de peças) e realizar treinamentos específicos constantes para adoção de melhores posturas

    Concurrent Validation and Reference Values of Gluteus Medius Clinical Test

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    # Context The hip abductor muscles, mainly the gluteus medius, are responsible for controlling hip adduction in a closed kinetic chain. Frontal plane knee alignment, assessed during functional activities such squatting, jumping and running, may overload joint structures, like the anterior cruciate ligament and patellofemoral joint. The hand-held dynamometer is reliable and effective for testing the muscular strength of the hip abductors. # Objectives (1) To assess the concurrent validity between the gluteus medius clinical test and a maximum isometric force test of the hip abductors using the hand-held dynamometer; (2) to determine the intra and inter-examiner reliability for the application of the gluteus medius clinical test; and (3) to describe reference values of gluteus medius clinical test on a population of youth athletes. # Design Cross-sectional. # Methods Thirty healthy individuals were recruited for validity and reliability testing. On the first day, participants performed the maximal isometric test of the hip abductors, measured via hand-held dynamometry. On the following week, the gluteus medius clinical test was performed. Intraclass correlation coefficients (ICC~2,2~) were computed for the reliability analysis, with a 95% confidence interval. To generate reference values, the gluteus medius clinical test was performed on 273 athletes. # Results The results of this study indicated a weak positive correlation (r = 0.436, p = 0.001) between tests, which indicates that they examine different domains of gluteus medius muscle function, likely endurance and muscle strength. The magnitude of computed ICCs (\>0.95) indicates excellent intra- and inter-examiner reliability. # Conclusion The findings of the current study indicate that the gluteus medius clinical test is reliable and examines a domain of muscular function not fully captured by HHD. The clinical test developed in this study is low-cost and can be included for gluteus medius assessment. # Level of evidence Level 3
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