302 research outputs found
Dificuldades de alunos do 1º ano do ensino médio na resolução de problemas matemáticos
Orientadora: Profª. Drª. Tania T. Bruns ZimerCoorientador:Trabalho de Conclusão de Curso (graduação) - Universidade Federal do Paraná, Setor de Ciências Exatas, Curso de Graduação em MatemáticaInclui referênciasResumo : Esta pesquisa teve o objetivo de identificar dificuldades de alunos do 1º ano do Ensino Médio, num colégio estadual de Curitiba, diante da resolução de problemas matemáticos envolvendo o conteúdo de funções do primeiro grau. O estudo trata de uma pesquisa de campo, realizada sob o contexto do estágio supervisionado obrigatório, que envolveu a observação participante em cinco turmas do 1º ano do Ensino Médio num colégio estadual de Curitiba, e contou com a aplicação de um teste contendo quatro problemas sobre função do primeiro grau para 25 alunos de uma dessas turmas. Seguindo as etapas de Polya (1995) foram desenvolvidos os seguintes critérios para analisar os desempenhos dos alunos: correto, parcialmente correto, errado, inconsistente e não fez, de modo que, por exemplo, a resolução foi considerada correta se foi possível perceber que ele compreendeu corretamente o problema (etapa 1), estabeleceu um plano coerente com o que estava proposto (etapa 2) e executou corretamente esse plano (etapa 3). Após a atribuição do desempenho para cada uma das soluções foi feita uma análise dentro das dificuldades presentes em cada uma das etapas. Através dessa análise foi constatada que a maior dificuldade dos alunos está relacionada com a assimilação do conceito de função.Abstract : The objective of this research is to identify difficulties of high school first year students, from a state school in Curitiba, facing mathematical problems involving functions of first degree functions. This is a field research conducted in the supervised internship that involved the observation in five classes of high school first year students, from a state school in Curitiba, included the application of a test containing four problems about first degree functions applied to 25 students in this class. Following the steps of Polya (1995) criteria were developed to analyze student performance: correct, partially correct, wrong, inconsistent and blank. For example, the resolution was considered correct if it could be seen that he correctly understood the problem (step 1), established a plan consistent with what was proposed (step 2) and correctly executed that plan (step 3). After assigning the performance for each of the solutions, an analysis was made within the difficulties present in each of the steps. Through this analysis it was found that the difficulty of the students is related to the assimilation of the concept of function
Stability-indicating RP-HPLC method for determination of beclomethasone dipropionate in nanocapsule suspensions
A simple stability-indicating RP-HPLC/UV method was validated for determination of beclomethasone dipropionate (BD) in nanocapsule suspensions. Chromatographic conditions consisted of a RP C18column (250 mm x 4.60 mm, 5 µm, 110 Å), using methanol and water (85:15 v/v) as mobile phase at 1.0 mL/min with UV detection at 254 nm. The calibration curve was found to be linear in the concentration range of 5.0-25.0 µg/mL with a correlation coefficient >; 0.999. Precision was demonstrated by a relative standard deviation lower than 2.0%. Accuracy was assessed by the recovery test of BD from nanocapsules (98.03% to 100.35%). Specificity showed no interference from the components of nanocapsules or from the degradation products derived from acid, basic and photolytic conditions. In conclusion, the method is suitable to be applied to assay BD in bulk drug and in nanocapsules, and it can be employed to study stability and degradation kinetics.Um método simples de CLAE-FR/UV indicativo de estabilidade foi validado para a determinação do dipropionato de beclometasona (BD) em suspensões de nanocápsulas. As condições cromatográficas foram: coluna C18 fase reversa (250 mm x 4,60 mm, 5 µm, 110 Å), usando como fase móvel metanol e água (85:15 v/v) a 1,0 mL/min, com detecção UV a 254 nm. A curva de calibração foi linear no intervalo de 5,0-25,0 µg/mL com coeficiente de correlação >;0,999. A precisão foi demonstrada por um desvio padrão relativo menor que 2,0%. A exatidão foi avaliada pelo teste de recuperação do BD a partir das nanocápsulas (98,03% a 100,35%). O teste de especificidade não mostrou interferência dos componentes das nanocápsulas e nem dos produtos de degradação derivados de condições ácidas, básicas e fotolíticas. Em conclusão, o método é adequado para ser aplicado na avaliação do BD puro e em nanocápsulas e pode ser empregado para o estudo de estabilidade e degradação cinética
Sodium risedronate-loaded poly(ε-caprolactone) nanoparticles: Development, physicochemical characterization, and in vitro drug release study
Objective: Osteoporosis is a chronic disease characterized by bone mass loss. Sodium risedronate (Na-Ris) is one of the most used drugs to its treatment. However, it has low oral bioavailability and exhibits many side effects. In order to overcome these limitations, the search for new dosage forms is necessary. One of these alternatives is the development of nanoparticles, which are able to transport the drug to its target directly, promoting maximization of the therapeutic efficiency and minimization of the toxicity. Due to its great versatility, these systems can be applied to an assorted administration routes, such as oral, pulmonary, intravenous, among others. Thus, the objective of this study was to develop Na-Ris-loaded nanoparticles and determine the drug release profile. Methods: Nanoparticles were prepared by solvent emulsification/evaporation method and characterized by mean size, polydispersity index, zeta potential, granulometric distribution, drug content and encapsulation efficiency. Afterwards, in vitro drug release was performed using the dialysis bag technique as well as the release kinetics were also studied. Results: The developed system has shown mean size of 193 ± 14 nm and polydispersity index around 0.2. Zeta potential was -9.76 ± 0,52 mV and slightly acid values for pH. The granulometric distribution demonstrated nanoparticles with a narrow size distribution and the absence of particles in the micrometer range. Regarding the in vitro release, the drug was released completely from the system in 240 minutes and the release kinetics has follow the zero-order equation. Final considerations: Thus, the Na-Ris-loaded nanoparticles were successfully developed and are a promising formulation for osteoporosis management.Population in all over the world is affected by bone diseases, such as osteoporosis and loss bone tissue. Sodium risedronate (Na-Ris) is one of the most used drugs to its treatment. However, it has low oral bioavailability and exhibits many side effects. In order to overcome these limitations, the search for new dosage forms is necessary. One of these alternatives is the development of nanoparticles, which are able to transport the drug to its target directly, promoting maximization of the therapeutic efficiency and minimization of the toxicity. Due to its great versatility, these systems can be applied to an assorted administration routes, such as oral, pulmonary, intravenous, among others. Thus, the objective of this study was to develop and characterize Na-Ris-loaded nanoparticles, as well as determine the drug release profile. Methods: Nanoparticles were prepared by solvent emulsification/evaporation method and characterized by mean size, polydispersity index, zeta potential, granulometric distribution, drug content and encapsulation efficiency. Afterwards, in vitro drug release was performed using the dialysis bag technique as well as the release kinetics were also studied. Results: The developed system has shown mean size of 193 ± 14 nm and polydispersity index around 0.2. Zeta potential was -9.76 ± 0,52 mV and slightly acid values for pH. The granulometric distribution demonstrated nanoparticles with a narrow size distribution and the absence of particles in the micrometer range. Regarding the in vitro release, the drug was released completely from the system in 240 minutes and the release kinetics has follow the zero-order equation. Final considerations: Thus, a nanocarrier containing a water-soluble drug was successfully developed, presenting adequate physicochemical characteristics, which can be promising for biological evaluations
Carbon stocks and pools in relation to the texture of kaolinitic soils from the brazilian east coast
Extremely kaolinitic soils of Tertiary age elevations on the Brazilian east coast present a wide range of texture, which is recognized as one of the main factors controlling the soil organic matter contents. This study aimed to investigate the organic C storage of different compartments of kaolinitic soils. The studied soils had a wide particle size gradient, were under native forest vegetation, and located on Brazil’s eastern coast (Coruripe - CF, Umbaúba - UF, Nova Viçosa - VF, Sooretama - SF, and Itaboraí - IF). The forest cover of all sites allows to record soil properties reference values for a land use condition closer to that of the original sites. We determined soil organic C (SOC) content and SOC stock up to a depth of 1 m, C of topsoil (0.00-0.08 m), aggregate size classes, and dissolved organic carbon (DOC) of the soil surface horizon (A horizon). Soil C stocks at the 0.00-1.00 m depth ranged from 105 to 137 Mg ha-1 and were not regulated by soil texture. The SF soils stored more C up to a depth of 1 m, while lower mean C stocks were found for UF and CF soils. Soil texture was not a reliable index to predict the C contents of the aggregate size classes of the 0.00-0.08 m layer (within each class and in total, using equivalent soil mass of the classes). The most clayey soils had a high percentage of 2-4 mm aggregates and, as a consequence, high aggregate stability indices, which are positively correlated to silt plus clay contents of the soil surface horizon. The proportion of DOC in relation to the total organic C of the surface soil horizon was high for IF and UF areas, which are the less preserved forest fragments among all studied fragments
Management in academic libraries : bibliometric study on the Web of Science
Realizou-se um estudo bibliométrico sobre os trabalhos publicados na temática Gestão do Conhecimento em Bibliotecas Universitárias (BU) no período de 2002 a 2020 na base de dados Web of Science. A metodologia na aplicação da análise bibliométrica usando o modelo de Marschner, Ávila e Sommer (2016) com adaptações. Fez-se uma revisão de literatura sobre a temática, se constatando que só existe o estudo de Bem e Reinisch (2014) que faz análise bibliométrica sobre GC em BU. Foram recuperados 48 trabalhos, dos quais foram analisados somente 33. Foram considerados somente aqueles pertencentes a área de Ciência da Informação e Biblioteconomia. Os resultados apontaram os anos mais produtivos entre 2017 e 2019. Os tipos de documentos são: artigos, early access e trabalhos em eventos, dos quais os artigos constituem a maior parte. O periódico com maior quantitativo de publicações é o Journal of Librarianship and Information Science. Os autores mais produtivos são: Ugwu, De Bem, Ekere e Rossi. As instituições que possuem mais publicações são: Universidade da África do Sul, Universidade da Nigéria e Universidade Federal de Santa Catarina. Os países que detêm um quantitativo maior de publicações são: África do Sul, Índia, Nigéria, Brasil, Paquistão e Espanha. As agências financiadoras são: Delta State University, ICSSR New Delhi, Ministry of Science and Innovation of The Government of Spain e University of Zululand. A produção científica na base é publicada nos idiomas inglês, português e espanhol, mas a principal língua é a inglesa. Conclui-se que os estudos sobre Gestão do Conhecimento em Bibliotecas Universitárias estão crescendo gradativamente e são recentes na base Web of Science.Se realizó un estudio bibliométrico sobre los trabajos publicados sobre el tema de la Gestión del Conocimiento en las Bibliotecas Universitarias en el período de 2002 a 2020 en la base de datos de Web of Science. La metodología en la aplicación del análisis bibliométrico utilizando el modelo de Marschner, Ávila y Sommer (2016) con adaptaciones. Se realizó una revisión de la literatura sobre el tema, que muestra que solo existe el estudio de Bem y Reinisch (2014) que realiza un análisis biométrico de KM en las BU. Se recuperaron 48 obras, de las cuales solo se analizaron 33. Solo se consideraron las pertenecientes al área de Ciencias de la Información y Biblioteconomía. Los resultados mostraron los años más productivos entre 2017 y 2019. Los tipos de documentos son: artículos, acceso temprano y trabajos en eventos, de los cuales los artículos constituyen la mayoría. La revista con el mayor número de publicaciones es el Journal of Librarianship and Information Science. Los autores más productivos son: Ugwu, De Bem, Ekere y Rossi. Las instituciones con más publicaciones son: Universidad de Sudáfrica, Universidad de Nigeria y Universidad Federal de Santa Catarina. Los países con mayor número de publicaciones son: Sudáfrica, India, Nigeria, Brasil, Pakistán y España. Las agencias de financiación son: Delta State University, ICSSR New Delhi, Ministerio de Ciencia e Innovación del Gobierno de España y la Universidad de Zululand. La producción científica en la base de datos se publica en inglés, portugués y español, pero el idioma principal es el inglés. Se concluye que los estudios sobre Gestión del Conocimiento en las Bibliotecas Universitarias están creciendo gradualmente y son recientes en la base Web of Science.A bibliometric study was carried out on the works published about Knowledge Management in University Libraries in the period from 2002 to 2020 in the Web of Science database. The methodology in the application of bibliometric analysis using the model of Marschner, Ávila and Sommer (2016) with adaptations. A literature review was made on the subject, showing that there is only the study by De Bem and Reinisch (2014) that does a biometric analysis on KM in BUs. 48 works were recovered, of which only 33 were analyzed. Only those belonging to the area of Information Science and Library Science were considered. The results showed the most productive years between 2017 and 2019. The types of documents are articles, Early access and works in events, of which articles make up the majority. The journal with the highest number of publications is the Journal of Librarianship and Information Science. The most productive authors are: Ugwu, De Bem, Ekere and Rossi. The institutions with the most publications are: University of South Africa, University of Nigeria and Federal University of Santa Catarina. The countries with the largest number of publications are: South Africa, India, Nigeria, Brazil, Pakistan and Spain. Funding agencies are: Delta State University, ICSSR New Delhi, Ministry of Science and Innovation of The Government of Spain and University of Zululand. The scientific production in the database is published in English, Portuguese and Spanish, but the main language is English. It is concluded that studies on Knowledge Management in University Libraries are gradually growing and are recent at the base Web of Science
Gestão do Conhecimento em bibliotecas universitárias: estudo bibliométrico na base web of science no período de 1945 a 2018
A bibliometric study was carried out on the work published in the topic Knowledge Management in University Libraries from 1945 to 2018 in the Web of Science database. The methodology consisted of research on the basis and application of bibliometric analysis in the localized works. A review of the literature on the subject was made, noting that there are so far no specific studies on the subject from the perspective of bibliometric analysis. Twenty-four studies were retrieved, of which only 22 were analyzed for dealing with Knowledge Management in University Libraries. The results pointed to the occurrence of the Law of Dispersion in the area. It also identifies that the keyword Knowledge management is most commonly used by applying Zipf's Law. It has been verified from Lotka's Law that the average author publishes 1 article. The production of the works, for the most part, occurs in co-authorship. They are published in journals of Chinese nationality (50%) and written in English (77%). The topic occurs most often in the field of Information Science Library Science. It is concluded that the studies on Knowledge Management in University Libraries are recent and are growing due to the perception of the importance of the sharing of intangible knowledge in the context of these Institutions
Gestão do Conhecimento em Bibliotecas Universitárias: estudo bibliométrico na base de dados Web of Science.
Realizou-se um estudo bibliométrico sobre os trabalhos publicados na temática Gestão do
Conhecimento em Bibliotecas Universitárias (BU) no período de 2002 a 2020 na base de dados Web of
Science. A metodologia na aplicação da análise bibliométrica usando o modelo de Marschner, Ávila e
Sommer (2016) com adaptações. Fez-se uma revisão de literatura sobre a temática, se constatando que
só existe o estudo de Bem e Reinisch (2014) que faz análise bibliométrica sobre GC em BU. Foram
recuperados 48 trabalhos, dos quais foram analisados somente 33. Foram considerados somente
aqueles pertencentes a área de Ciência da Informação e Biblioteconomia. Os resultados apontaram os
anos mais produtivos entre 2017 e 2019. Os tipos de documentos são: artigos, early access e trabalhos
em eventos, dos quais os artigos constituem a maior parte. O periódico com maior quantitativo de
publicações é o Journal of Librarianship and Information Science. Os autores mais produtivos são: Ugwu,
De Bem, Ekere e Rossi. As instituições que possuem mais publicações são: Universidade da África do Sul,
Universidade da Nigéria e Universidade Federal de Santa Catarina. Os países que detêm um quantitativo
maior de publicações são: África do Sul, Índia, Nigéria, Brasil, Paquistão e Espanha. As agências
financiadoras são: Delta State University, ICSSR New Delhi, Ministry of Science and Innovation of The
Government of Spain e University of Zululand. A produção científica na base é publicada nos idiomas
inglês, português e espanhol, mas a principal língua é a inglesa. Conclui-se que os estudos sobre Gestão
do Conhecimento em Bibliotecas Universitárias estão crescendo gradativamente e são recentes na base
Web of ScienceLibraries in the period from 2002 to 2020 in the Web of Science database. The methodology
in the application of bibliometric analysis using the model of Marschner, Ávila and Sommer (2016) with
adaptations. A literature review was made on the subject, showing that there is only the study by De
Bem and Reinisch (2014) that does a biometric analysis on KM in BUs. 48 works were recovered, of
which only 33 were analyzed. Only those belonging to the area of Information Science and Library
Science were considered. The results showed the most productive years between 2017 and 2019. The
types of documents are articles, Early access and works in events, of which articles make up the
majority. The journal with the highest number of publications is the Journal of Librarianship and
Information Science. The most productive authors are: Ugwu, De Bem, Ekere and Rossi. The institutions
with the most publications are: University of South Africa, University of Nigeria and Federal University of
Santa Catarina. The countries with the largest number of publications are: South Africa, India, Nigeria,
Brazil, Pakistan and Spain. Funding agencies are: Delta State University, ICSSR New Delhi, Ministry of
Science and Innovation of The Government of Spain and University of Zululand. The scientific production
in the database is published in English, Portuguese and Spanish, but the main language is English. It is
concluded that studies on Knowledge Management in University Libraries are gradually growing and are
recent at the base Web of Science.Se realizó un estudio bibliométrico sobre los trabajos publicados sobre el tema de la Gestión
del Conocimiento en las Bibliotecas Universitarias en el período de 2002 a 2020 en la base de datos de
Web of Science. La metodología en la aplicación del análisis bibliométrico utilizando el modelo de
Marschner, Ávila y Sommer (2016) con adaptaciones. Se realizó una revisión de la literatura sobre el
tema, que muestra que solo existe el estudio de Bem y Reinisch (2014) que realiza un análisis biométrico
de KM en las BU. Se recuperaron 48 obras, de las cuales solo se analizaron 33. Solo se consideraron las
pertenecientes al área de Ciencias de la Información y Biblioteconomía. Los resultados mostraron los años más productivos entre 2017 y 2019. Los tipos de documentos son: artículos, acceso temprano y
trabajos en eventos, de los cuales los artículos constituyen la mayoría. La revista con el mayor número
de publicaciones es el Journal of Librarianship and Information Science. Los autores más productivos
son: Ugwu, De Bem, Ekere y Rossi. Las instituciones con más publicaciones son: Universidad de
Sudáfrica, Universidad de Nigeria y Universidad Federal de Santa Catarina. Los países con mayor número
de publicaciones son: Sudáfrica, India, Nigeria, Brasil, Pakistán y España. Las agencias de financiación
son: Delta State University, ICSSR New Delhi, Ministerio de Ciencia e Innovación del Gobierno de España
y la Universidad de Zululand. La producción científica en la base de datos se publica en inglés, portugués
y español, pero el idioma principal es el inglés. Se concluye que los estudios sobre Gestión del
Conocimiento en las Bibliotecas Universitarias están creciendo gradualmente y son recientes en la base
Web of Science
Pullulan as a stabilizer agent of polymeric nanocapsules for drug delivery
Polymeric stabilizers have received attention in the preparation of nanostructured systems due to their ability to enhance formulation stability. Considering this, the objective of this work was to prepare poly(ε-caprolactone) nanocapsules using the pullulan as a polymeric stabilizer. The nanocapsules were prepared using the interfacial deposition method of preformed polymers and they were characterized in terms of pH, average diameter, polydispersity index, zeta potential, beclomethasone dipropionate content, encapsulation efficiency, photostability and drug release profiles. The formulations showed physicochemical characteristics consistent with nanocarriers for drug delivery such as: average diameter lower than 270 nm, polydispersity indexes lower than 0.2, negative zeta potential (-22.7 to -26.3 mV) and encapsulation efficiencies close to 100%. In addition, the nanocapsules were able to delay the beclomethasone dipropionate photodegradation under UVC radiation and by the dialysis bag diffusion technique, the nanocapsules were able to prolong the drug release. Thus, pullulan could be considered an interesting excipient to formulate polymeric nanocapsules
Education of networks of university libraries: a case study in the Federal Rural University of Amazonia).
As bibliotecas procuram, cada vez mais, novas formas de disponibilizar o seu
acervo e dinamizar os serviços e produtos, buscando trabalhar de maneira cooperativa com
outras unidades de informação. O presente trabalho tem como objetivo mostrar o processo de
formação da Rede de Bibliotecas da Universidade Federal Rural da Amazônia, visando
melhorar os processos de gestão e acesso a informação. Foi realizado um estudo de caso na
instituição, por meio da descrição dos encontros de bibliotecários. A coleta de dados foi
realizada através do registro documental dos materiais gerados nestas reuniões. Considera-se
pontos importantes para a fundamentação teórica, os conceitos de rede, cooperativas de
bibliotecas, os fatores de sucesso e fracasso e cita-se alguns exemplos de consócios, sistemas
e redes de bibliotecas no Brasil. Entende-se com este estudo que as bibliotecas universitárias,
necessitam trabalhar de forma integrada como é o caso da instituição em questão, objeto deste
estudo. No que se refere aos resultados foi possível observar também que a formação das
redes permitiu o compartilhamento da informação em escala maior alcançando assim a
comunidade interna e externa e o estudo de caso demonstrou a importância do trabalho
participativo, sendo as tomadas de decisões igualmente democráticas.Libraries increasingly seek new ways of making their collections available and
invigorating services and products, seeking to work cooperatively with other information
units. The present work aims to show the process of formation of the Libraries Network of the
Federal Rural University of Amazonia, aiming to improve the processes of management and
access to information. A case study was carried out at the institution, through the description
of the librarian meetings. The data collection was done through the documentary record of the
materials generated in these meetings. It is considered important points for the theoretical
foundation, network concepts, library cooperatives, success and failure factors, and some examples of partnerships, systems and networks of libraries in Brazil. It is understood with
this study that the university libraries, need to work in an integrated way as is the case of the
institution in question, object of this study. Regarding the results, it was also possible to
observe that the formation of networks allowed the sharing of information on a larger scale,
thus reaching the internal and external community, and the case study demonstrated the
importance of participatory work, and decision making is equally democratic
Food consumption and eating behavior among Brazilian adolescents: National Adolescent School-based Health Survey (PeNSE), 2009
O objetivo deste artigo é descrever características de consumo e comportamento alimentar de adolescentes brasileiros e sua associação com fatores sociodemográficos. Estudou-se, em 2009, amostra representativa de alunos do 9º ano do ensino fundamental de escolas públicas e privadas das 26 capitais brasileiras e do Distrito Federal. Utilizou-se questionário autoaplicável sobre atributos sociodemográficos, consumo e comportamento alimentar, entre outros. Estimativas dos indicadores construídos foram apresentadas para o total da população e por sexo. A associação de cada um dos indicadores com variáveis sociodemográficas foi examinada por meio de regressão logística. A maioria dos adolescentes consumia regularmente feijão (62,6%), leite (53,6%) e guloseimas (50,9%), realizava pelo menos o almoço ou o jantar com a mãe ou responsável (62,6%) e comia assistindo televisão ou estudando (50,9%). Em geral, as meninas estavam mais expostas a práticas alimentares não desejáveis, e o melhor nível socioeconômico associou-se a maiores prevalências dos indicadores estudados. Os resultados revelaram consumo regular dos marcadores de alimentação não saudável e consumo inferior ao recomendado dos de alimentação saudável, apontando a necessidade de ações de promoção de saúde dirigidas a jovens.The objective of this article is to describe the characteristics of food consumption and eating behavior of adolescents and its association with socio-demographic factors. In 2009, a random sample of students in 9th grade of elementary education at public and private schools from 26 Brazilian state capitals and Federal District was studied. It was applied a self-administered questionnaire with socio-demographic attributes, food consumption and eating behavior, among others. Estimates of the constructed indicators were presented for the total population and by sex. The association of each indicator with socio-demographic variables was examined by logistic regression. The results showed that over half of adolescents presented frequent consumption of beans (62.6%), milk (53.6%) and sweets (50.9%), and held at least lunch or dinner with the mother or responsible (62.6%) and watching television or studying (50.9%). In general, girls were more exposed to undesirable eating habits and higher socioeconomic status was associated with a higher prevalence of the indicators studied. The results revealed regular consumption of unhealthy diet markers and consumption of less than the recommended for a healthy diet, pointing the need for strengthening health promotion activities targeting young people
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