2,363 research outputs found

    A methodology to obtain accurate potential energy Functions for diatomic systems: mathematical point of view

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    The mathematics used in physical chemistry has changed greatly in the past forty years and it will certainly continue to change more quickly. Theoretical chemists and physicists must have an acquaintance with abstract mathematics if they are to keep up with their field, as the mathematical language in which it is expressed changes. Thinking about it, in this article, we want to show some of the most important concepts of Mathematical Analysis involved in obtaining analytical functions to represent the potential energy interaction for diatomic systems. A basic guide for the construction of a potential based on Dunham's coefficients and an example of a new potential obtained from this methodology is also presented

    ANALYSIS OF DISCRIMINATORY GAME VARIABLES BETWEEN WINNERS AND LOSERS IN WOMEN’S HANDBALL WORLD CHAMPIONSHIPS FROM 2007 TO 2017

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    The aim of this study was to identify game variables that discriminated winning from losing teams and to understand how these variables contributed to victory by observing goal differences in matches of the women’s handball world championships. The sample comprised 471 WCh’s games played between 2007 and 2017. The games were grouped into three clusters: balanced games – difference of 1-8 goals; unbalanced games – difference of 9-20 goals; and very unbalanced games – difference of > 20 goals. Generally, the performance of winning teams was significantly higher (in most variables), or lower in the case of the number of technical faults (p<.05). In the balanced games, there was a greater contribution of defensive variables (stolen balls, blocked throws, and goalkeeper’s efficiency indicators) in relation to attack variables (attack efficiency and throw efficiency indicators). For victory, the number of technical faults reduce the chances of winning. Games with the unbalanced and very unbalanced goal differences seem to follow the same tendency; however, in the very unbalanced games, there were more assists, yellow cards and 2-min suspensions. We concluded that the decisive variables for victory in the balanced games showed a greater weight, with a special emphasis on stolen balls followed by offensive variables (throw efficiency indicators, attack efficiency, and technical faults). There was an equal tendency for the games with unbalanced and very unbalanced outcomes

    Extraction of bioactive compounds from Curcuma longa L. using deep eutectic solvents: in vitro and in vivo biological activities

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    In this work, deep eutectic solvents (DES-based menthol and cholinium chloride) and the ethanol, temperature, and times were selected to extract bioactive compounds from the rhizome, leaves, and flowers Curcuma longa L., using ultrasound-assisted extraction. Analyzes antioxidant, flavonoids, antimicrobial, chelation Fe2+, inhibition of the cholinesterase's enzymes, cytotoxicity, and genotoxicity in Allium cepa cells were performed. The extracts showed results of iron chelation and antibacterial. Curcuma flowers and leaves' extracts inhibited food spoilage bacteria with values above 45%, with substantial iron-chelating activity above 50%. Extracts obtained by DES based on menthol and lactic acid exhibited a high percentage of inhibition of acetyl and butyryl cholinesterase. In contrast, flower extracts obtained by menthol and acetic acid showed low inhibition of cholinesterase enzyme activity. No extract showed cytotoxicity and genotoxicity. Biological activities showed a high potential for the application of these extracts in the food and pharmaceutical industries.This study was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) – Finance Code 001. The authors thank both CAPES for the financial support, the Federal University of Paraná (UFPR) and the Federal University of Technology - Paraná (UTFPR), Labmulti-CM (UTFPR) for the technical support provided. M. R. Mafra and L. Igarashi-Mafra are grateful to the Brazilian National Council for Scientific and Technological Development (CNPq - Grant 310182/2018-2 and 308517/2018-0, respectively).info:eu-repo/semantics/publishedVersio

    Knocking Down Low Molecular Weight Protein Tyrosine Phosphatase (LMW-PTP) Reverts Chemoresistance through Inactivation of Src and Bcr-Abl Proteins

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    The development of multidrug resistance (MDR) limits the efficacy of continuous chemotherapeutic treatment in chronic myelogenous leukemia (CML). Low molecular weight protein tyrosine phosphatase (LMW-PTP) is up-regulated in several cancers and has been associated to poor prognosis. This prompted us to investigate the involvement of LMW-PTP in MDR. In this study, we investigated the role of LMW-PTP in a chemoresistant CML cell line, Lucena-1. Our results showed that LMW-PTP is highly expressed and 7-fold more active in Lucena-1 cells compared to K562 cells, the non-resistant cell line. Knocking down LMW-PTP in Lucena-1 cells reverted chemoresistance to vincristine and imatinib mesylate, followed by a decrease of Src and Bcr-Abl phosphorylation at the activating sites, inactivating both kinases. On the other hand, overexpression of LMW-PTP in K562 cells led to chemoresistance to vincristine. Our findings describe, for the first time, that LMW-PTP cooperates with MDR phenotype, at least in part, through maintaining Src and Bcr-Abl kinases in more active statuses. These findings suggest that inhibition of LMW-PTP may be a useful strategy for the development of therapies for multidrug resistant CML

    A methodology to obtain accurate potential energy Functions for diatomic systems: mathematical point of view

    Get PDF
    The mathematics used in physical chemistry has changed greatly in the past forty years and it will certainly continue to change more quickly. Theoretical chemists and physicists must have an acquaintance with abstract mathematics if they are to keep up with their field, as the mathematical language in which it is expressed changes. Thinking about it, in this article, we want to show some of the most important concepts of Mathematical Analysis involved in obtaining analytical functions to represent the potential energy interaction for diatomic systems. A basic guide for the construction of a potential based on Dunham's coefficients and an example of a new potential obtained from this methodology is also presented

    El nivel de satisfacción de los usuarios de envases de conserva (vidrio), cuanto a la apertura de las mismas

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    Desde los tiempos más remotos, el hombre busca soluciones para trasportar y almacenar sus productos. Debido a la evolución de las actividades comerciales, el envase pasó, a lo largo del tiempo, a acumular funciones, superando las necesidades iniciales de transporte y de conservación de los productos, transformándose también en importante vehículo de comunicación

    Multi-scale assessment of human-induced changes to Amazonian instream habitats

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    Context Land use change and forest degradation have myriad effects on tropical ecosystems. Yet their consequences for low-order streams remain very poorly understood, including in the world´s largest freshwater basin, the Amazon. Objectives Determine the degree to which physical and chemical characteristics of the instream habitat of low-order Amazonian streams change in response to past local- and catchment-level anthropogenic disturbances. Methods To do so, we collected field instream habitat (i.e., physical habitat and water quality) and landscape data from 99 stream sites in two eastern Brazilian Amazon regions. We used random forest regression trees to assess the relative importance of different predictor variables in determining changes in instream habitat response variables. Results Multiple drivers, operating at multiple spatial scales, were important in determining changes in the physical habitat and water quality of the sites. Although we found few similarities in modelled relationships between the two regions, we observed non-linear responses of specific instream characteristics to landscape change; for example 20 % of catchment deforestation resulted in consistently warmer streams. Conclusions Our results highlight the importance of local riparian and catchment-scale forest cover in shaping instream physical environments, but also underscore the importance of other land use changes and activities, such as road crossings and upstream agriculture intensification. In contrast to the property-scale focus of the Brazilian Forest code, which governs environmental regulations on private land, our results reinforce the importance of catchment-wide management strategies to protect stream ecosystem integrity

    Uso de árvores nativas em pastagens agroecológicas

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    O conhecimento tradicional tem sido a base da parceria entre o Centro de Tecnologias Alternativas, as organizações dos agricultores familiares da Zona da Mata de Minas Gerais e as Universidades Federais de Viçosa e, mais recentemente, de Lavras. O objetivo desse trabalho foi identificar o conhecimento tradicional sobre os usos comuns de árvores nativas em pastagens de famílias agricultoras dos municípios de Divino e Araponga, aplicando metodologias participativas (observação participante e entrevista semi-estruturada). O principal uso da terra na região é com café e pastagens. Foi observado pelas famílias que os animais comem ramos de Solanum mauritianum, Senna macranthera, Aegiphila sellowiana e Inga edulis. De acordo com as famílias, a maioria das árvores já estava na pastagem antes do capim. É necessário aprofundamento que dialogue com o aprendizado de famílias agricultoras.Traditional knowledge has been the main base of the partnership among the Center of Alternative Technologies, the organizations of family farmers of Zona da Mata of Minas Gerais and the Federal Universities of Viçosa and, more recently, of Lavras. The objective was to identify the traditional knowledge about the common uses of native trees in the pastures of the properties of family farmers in the municipalities of Divino and Araponga, applying qualitative methodologies (participant observation and semi-structured interviews). The land use in the region is mainly coffee and pastures. Was observed by the families that the animals feed themselves with branches of Solanum mauritianum, Senna macranthera, Aegiphila sellowiana and Inga edulis. According to the families the majority of the trees was already in the field before the grass. It is necessary to deep the dialogue to keep leaning and exchange knowledge with smallholders families.Eje A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale
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