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The aim of this investigation was to study and evaluate the fracture toughness (KICV) of an AISI M3:2 high speed steel that was prepared by powder metallurgical processing, which consisted of uniaxial cold compaction of irregularly shaped water atomized powders, without and with 0.3% of carbon in the form of graphite, followed by vacuum sintering to obtain compacts with densities close to its theoretical value. The sintered steels were then hardened by austenitizing, quenching and triple tempering. Chevron fracture toughness test samples were prepared from the compacts and the tests conducted to determine KICV. The microstructures of the specimens were examined by scanning electron microscopy (SEM), and the composition of the phases determined by x-ray diffraction analysis (XRD). The sizes of the primary carbides and of the austenite grains were determined using Quantikov digital analysis software. No significant difference in fracture toughness (KICV) between the two high speed steels AISI M3:2, austenitized at the different temperatures, was observed.

https://doi.org/10.1590/1980-5373-mr-2023-0179

Sobre a prática científica dos economistas brasileiros: entre a virtude epistêmica e a administração da irrelevância
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Aguilar Filho, Hélio Afonso de

; Neves, Fabrício Monteiro

Sociedade e Estado

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2023, Volume 38 N. 3 elocation e45502

Abstract: En Pt | Text: En Pt | PDF: En | PDF: Pt

Abstract Economists justify the internationalization of economic science using meta-language in such a way that competition is presented as an “exemplary” mechanism which increases the quality (epistemic credibility) and productivity (the absorption of new knowledge) of science. However, competition from the perfect markets of economic theory is rarely found in the real world, much less in science, where a combination of material and symbolic factors reinforces the uneven and hierarchical character of scientific production. Based on this understanding, the present work uses the concept of the ‘Irrelevance Administration Regime’ to understand the inducing structure of scientific processes in which the knowledge produced is considered to be inferior. More specifically, the objective of this paper is to clarify elements that contribute to the existence of a self-deprecated attentional dynamic, focusing on economists’ conscious or unconscious daily scientific practices.

Resumo Os economistas justificam a internacionalização da ciência econômica recorrendo à metalinguagem, de tal modo que a competição é apresentada como o mecanismo “exemplar” de estímulo à qualidade (credibilidade epistêmica) e produtividade da ciência (novos conhecimentos). Entretanto, a competição dos mercados perfeitos da teoria econômica raramente é encontrada no mundo real, muito menos na ciência, onde uma combinação de fatores materiais e simbólicos reforça o caráter desigual e hierárquico da produção científica. Partindo desse entendimento, o presente trabalho lança mão do conceito de “regime de administração da irrelevância” para compreender a ordem indutora de processos científicos nos quais o conhecimento produzido é diminuído a uma condição de inferioridade ante outros contextos. Mais especificamente, o objetivo será evidenciar, a partir de procedimentos conscientes ou não, a prática científica cotidiana dos economistas, elementos que contribuem para a existência de uma dinâmica atencional autodepreciada.

https://doi.org/10.1590/s0102-6992-e45502

Allometric equations for biomass and contents of macronutrients in a young Tectona grandis stand
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Santos, Márcio Luiz dos

; Leite, Helio Garcia

; Cavalcante, Valéria Santos

; Fernandes, Loane Vaz

; Neves, Júlio César Lima

Revista Brasileira de Ciência do Solo

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2022, Volume 46 elocation e0220030

Abstract: En | Text: En | PDF: En

ABSTRACT Evaluations of biomass and nutrient contents in teak stands are necessary alternatives for avoiding early cutting to provide supplemental data for the plant module of fertilization recommendation systems. This study aimed to adjust allometric equations to estimate the accumulation of biomass and nutrient contents in teak plantations in the central region of Brazil. Plots in seminal and clonal stands contained 81 trees aged 75 months, that had not received previous fertilization or thinning. Additional clonal stands aged 15, 51 and 63 months and a seminal stand aged 63 months had been previously fertilized during implantation. Allometric equations for biomass and macronutrient contents were obtained for components of the aerial parts of trees as a function of diameter at 1.3 m height (DBH), and the possibility of using an equation or the need for specific equations was evaluated for genetic material (seminal or clonal) and the fertilization scheme (not fertilized or fertilized). The equations adjusted to the four sets of stands, all with elevated predictive capacity, did not differ among each other based on an identity test. Thus, the use of a robust equation adjusted with data from all stands is recommended to obtain estimates with a high degree of accuracy. The biomass and accumulation of macronutrients in components of the aerial parts of teak trees should be considered to obtain the nutrient contents in both the exportable components in thinned trees and the components maintained in the area and available for biogeochemical cycling.

https://doi.org/10.36783/18069657rbcs20220030

Cannabinoids in Neurology - Position paper from Scientific Departments from Brazilian Academy of Neurology
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BRUCKI, Sonia Maria Dozzi

; ADONI, Tarso

; ALMEIDA, Carlos Mauricio Oliveira

; ANDRADE, Daniel Ciampi de

; ANGHINAH, Renato

; BARBOSA, Luciana Mendonça

; BAZAN, Rodrigo

; CARVALHO, Alzira Alves de Siqueira

; CARVALHO, William

; CHRISTO, Paulo Pereira

; COLETTA, Marcus Della

; CONFORTO, Adriana Bastos

; CORREA-NETO, Ylmar

; ENGELHARDT, Eliasz

; FRANÇA JUNIOR, Marcondes Cavalcante

; FRANCO, Clelia

; VON GLEHN, Felipe

; GOMES, Helio Rodrigues

; HOULY, Caroline Gomes de Barros

; KAUP, Alexandre Ottoni

; KOWACS, Fernando

; KANASHIRO, Aline

; LOPES, Victor Gonçalves

; MAIA, Débora

; MANREZA, Maria

; MARTINEZ, Alberto Rolim Muro

; MARTINEZ, Sandra Cristina Gonçalves

; NADER, Saulo Nardy

; NEVES, Luciana de Oliveira

; OKAMOTO, Ivan Hideyo

; OLIVEIRA, Rogério Adas Ayres de

; PEIXOTO, Fabiano de Melo

; PEREIRA, Cristiana Borges

; SABA, Roberta Arb

; SAMPAIO, Leticia Pereira de Brito

; SCHILLING, Lucas Porcello

; SILVA, Marcus Tulius Teixeira

; SILVA, Emanuelle Roberta

; SMID, Jerusa

; SOARES, Cristiane Nascimento

; SOBREIRA-NETO, Manoel

; SOUSA, Nise Alessandra de Carvalho

; SOUZA, Leonardo Cruz de

; TEIVE, Hélio Afonso Ghizoni

; TERRA, Vera Cristina

; VALE, Matheus

; VIEIRA, Vitor Mendes Grise

; ZANOTELI, Edmar

; PRADO, Gilmar

Arquivos de Neuro-Psiquiatria

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apr 2021, Volume 79 N. 4 Pages 354 - 369

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

RESUMO Os canabinoides compreendem os endocanabinoides, fitocanabinoides e os canabinoides sintéticos e desempenham ações no sistema nervoso central e periférico. Uma quantidade enorme de publicações tem sido lançada nos últimos anos, embora a cannabis seja conhecida por milênios. Os Departamentos Científicos da Academia Brasileira de Neurologia descreveram as evidências do uso médico em suas áreas. A literatura está em constantes mudanças e possíveis novas evidências podem surgir nos próximos dias ou meses. A prescrição dessas substâncias deve ser discutida com os pacientes e suas famílias, com conhecimento sobre eventos adversos e sua eficácia.

ABSTRACT Cannabinoids comprehend endocannabinoids, phytocannabinoids, and synthetic cannabinoids, with actions both in the central and peripherical nervous systems. A considerable amount of publications have been made in recent years, although cannabis has been known for over a thousand years. Scientific Departments from the Brazilian Academy of Neurology described evidence for medical use in their areas. Literature is constantly changing, and possible new evidence can emerge in the next days or months. Prescription of these substances must be discussed with patients and their families, with knowledge about adverse events and their efficacy.

https://doi.org/10.1590/0004-282x-anp-2020-0432 1049 downloads

Refractory Ceramics of Clay and Alumina Waste
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Silva, Valmir José da

; Taveira, Salvador K. A.

; Silva, Karina R.

; Neves, Gelmires A.

; Lira, Hélio L.

; Santana, Lisiane N. L.

Materials Research

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2021, Volume 24 N. 2 elocation e20200485

Abstract: En | Text: En | PDF: En

Abstract Refractory ceramics were produced from clays and alumina waste. Specimens were shaped by uniaxial pressing, subjected to thermal analysis by dilatometry and heat-treated in a conventional furnace at 1300 and 1400ºC, applying a heating rate of 5ºC/min and a dwell time of 2 and 3 hours at the maximum temperature. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and physicomechanical properties. The dilatometric analysis before heat treatment indicated that the formulation containing the largest amount of fluxing oxides presented the highest linear shrinkage. The XRD analysis revealed that mullite was the major phase and needle shaped crystals typical of mullite obtained from clay minerals were observed by SEM. The increase in firing temperature and dwell time at the maximum temperature improved the physicomechanical properties of the specimens. The thermal expansion coefficient (TEC) in the range of 25 to 1000ºC varied from 6.2 to 6.9 x 10-6°C-1.

https://doi.org/10.1590/1980-5373-mr-2020-0485 616 downloads

Influência de diferentes solventes na síntese de mulita por sol-gel
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Braga, Aluska do Nascimento Simões

; Carvalho, Geysivana Kessya Garcia

; Lira, Hélio de Lucena

; Neves, Gelmires de Araújo

; Menezes, Romualdo Rodrigues

Matéria (Rio de Janeiro)

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2021, Volume 26 N. 2 elocation e12983

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

RESUMO Mulita é um material que tem recebido atenção especial devido às suas propriedades químicas, físicas e mecânicas, que estão correlacionadas com o método de síntese utilizado. O método sol-gel destaca-se frente aos outros métodos químicos devido à possibilidade de obtenção de materiais com elevado grau de pureza e baixas temperaturas de síntese. Sendo assim, este trabalho teve por objetivo a análise dos solventes água, álcool etílico, álcool isopropílico e tetrahidrofurano, na obtenção de mulita por meio da rota sol-gel. As amostras foram caracterizadas por difração de raios X (DRX), análise termogravimétrica e diferencial (TG/ATD), adsorção de nitrogênio, microscopia eletrônica de varredura (MEV) e microscopia eletrônica de transmissão (MET). Os resultados mostraram que a mulita foi sintetizada com todos os solventes, porém, o uso dos álcoois como solvente proporcionou a obtenção das amostras mais cristalinas, com as menores perdas de massa, com uma morfologia formada por agregados e partículas individualizadas.

ABSTRACT Mullite is a material that has received special attention due to its chemical, physical and mechanical properties, which are correlated with the synthesis method used. The sol-gel method stands out compared to other chemical methods due to the possibility of obtaining materials with a high degree of purity and low synthesis temperatures. Thus, this work aimed to analyze the solvents water, ethyl alcohol, isopropyl alcohol and tetrahydrofuran, in obtaining mullite using the sol-gel route. The samples were characterized by X-ray diffraction (XRD), thermogravimetric and differential analysis (TG/DTA), nitrogen adsorption (BET), scanning electron microscopy (SEM) and transmission electron microscopy (MET). The results showed that mullite was synthesized with all solvents, however, the use of alcohols as a solvent provided the obtaining of the most crystalline samples, with the lowest mass losses, with a morphology formed by aggregates and individualized particles.

https://doi.org/10.1590/s1517-707620210002.1283 123 downloads

Acidente de trabalho com material biológico: fatores associados ao abandono do acompanhamento clínico-laboratorial
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Sardeiro, Tatiana Luciano

; Souza, Camila Lucas de

; Salgado, Thaís de Arvelos

; Galdino Júnior, Hélio

; Neves, Zilah Cândida Pereira

; Tipple, Anaclara Ferreira Veiga

Revista da Escola de Enfermagem da USP

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dec 2019, Volume 53 elocation e03516

Abstract: En Es Pt | Text: En Es Pt | PDF: En | PDF: Es | PDF: Pt

ABSTRACT Objective: To analyze the epidemiology of abandoning clinical and laboratory follow-up among health workers who suffered accidents with biological material. Method: Cohort study based on reported work accidents with biological material in Goiânia/Goiás. Data were analyzed in Stata with descriptive and analytical statistics. Results: 2,104 exposures of the 8,596 reported accidents were analyzed, most of them involving females with completed high school education and belonging to the nursing staff. The accidents predominantly occurred by percutaneous injury involving a needle with lumen during medication administration or vascular access. Follow-up abandonment rate was 41.5%. Predictive factors for discontinuing clinical and laboratory follow-up were age, occupation, use of personal protective equipment (gowns), the object involved in the accident, situation in the labor market, circumstance of exposure and recommended prophylactic conduct. Conclusion: Given the high abandonment rate found, it is suggested to implement strategies to ensure follow-up and reduce risks to health workers.

RESUMEN Objetivo: Analizar la epidemiología del abandono del seguimiento clínico y de laboratorio entre los trabajadores del área sanitaria que sufrieron accidente con material biológico. Método: Estudio de cohorte realizado a partir de los accidentes laborales con material biológico notificados en Goiânia/Goiás. Los datos fueron analizados en el Stata con estadística descriptiva y analítica. Resultados: De los 8.596 accidentes notificados, fueron analizadas 2.104 exposiciones, la mayoría del sexo femenino, con nivel escolar de educación secundaria y perteneciente al equipo de enfermería. Los accidentes ocurrieron, predominantemente, por lesión percutánea, involucrando aguja con lumen, durante administración de fármacos o acceso vascular. La tasa de abandono del seguimiento fue del 41,5%. Los factores predictores para la interrupción del seguimiento clínico y de laboratorio fueron edad, ocupación, uso del equipo de protección individual (delantal), objeto involucrado en el accidente, situación en el mercado laboral, circunstancia de la exposición y conductas profilácticas recomendadas. Conclusión: Ante la elevada tasa de abandono encontrada, se sugiere la implementación de estrategias para asegurar el seguimiento y reducir los riesgos para el trabajador.

RESUMO Objetivo: Analisar a epidemiologia do abandono do acompanhamento clínico-laboratorial entre os trabalhadores da área da saúde que sofreram acidente com material biológico. Método: Estudo de coorte realizado a partir dos acidentes de trabalho com material biológico notificados em Goiânia/Goiás. Os dados foram analisados no Stata com estatística descritiva e analítica. Resultados: Dos 8.596 acidentes notificados, foram analisadas 2.104 exposições, a maioria no sexo feminino, com ensino médio completo e pertencente à equipe de enfermagem. Os acidentes ocorreram, predominantemente, por lesão percutânea, envolvendo agulha com lúmen, durante administração de medicamentos ou acesso vascular. A taxa de abandono do acompanhamento foi de 41,5%. Os fatores preditores para a interrupção do seguimento clínico-laboratorial foram idade, ocupação, uso de equipamento de proteção individual (avental), objeto envolvido no acidente, situação no mercado de trabalho, circunstância da exposição e condutas profiláticas recomendadas. Conclusão: Frente à elevada taxa de abandono encontrada, sugere-se a implementação de estratégias para garantir o seguimento e reduzir os riscos para o trabalhador.

https://doi.org/10.1590/s1980-220x2018029703516 6 downloads

Acidente de trabalho com material biológico: fatores associados ao abandono do acompanhamento clínico-laboratorial
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Sardeiro, Tatiana Luciano

; Souza, Camila Lucas de

; Salgado, Thaís de Arvelos

; Galdino Júnior, Hélio

; Neves, Zilah Cândida Pereira

; Tipple, Anaclara Ferreira Veiga

Revista da Escola de Enfermagem da USP

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2019, Volume 53 elocation e03516

Abstract: Pt En Es | Text: Pt En Es | PDF: Pt | PDF: En | PDF: Es

https://doi.org/10.1590/s1980-220x2018029703516 2334 downloads

Evaluation of Fracture Toughness of Ultraviolet-Irradiated Polycarbonate Using the Essential Work of Fracture Method
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Oliveira, Celio Jorge Vasques de

; Weber, Ricardo Ponde

; Monteiro, Sergio Neves

; Vital, Hélio Carvalho

; Dias, Marcos Lopes

Materials Research

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2018, Volume 21 elocation e20171079

Abstract: En | Text: En | PDF: En

The essential work of fracture (EWF) method provides useful parameters to characterize the fracture toughness of polymers exposed to degrading environments under conditions associated with plane-stress state of failure. Exposure of polymeric engineering materials to ultraviolet (UV) radiation may produce macromolecular changes that impair their fracture toughness. In the present work, for the first time, the EWF method applying a double edge notched tensile specimen was used to quantify the fracture toughness behavior of polycarbonate (PC) exposed to different, 300 h and 600 h, UV irradiation times. In addition, molar weight M ─ n determination, differential scanning calorimetry (DSC), Fourier transformed infrared spectroscopy (FTIR) and tensile tests were also investigated for non-irradiated and UV irradiated PC. The EWF results and scanning electron microscopy analysis revealed a significant reduction (39 % for 300h and 45 % for 600h of UV exposure) in fracture toughness associated with scission of the macromolecular chains. Other investigated properties, such as M ─ n, glass transition temperature, oxidation index and tensile strength, despite decreasing with UV exposure, did not show conclusive values.

https://doi.org/10.1590/1980-5373-mr-2017-1079 1274 downloads

10.

Avaliação das composições de massas argilosas a partir da incorporação de resíduo da indústria de cerâmica vermelha na obtenção de membranas cerâmicas tubulares
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Silva, Adriano Lima da

; Chaves, Alexsandra Cristina

; Luna, Carlos Bruno Barreto

; Neves, Gelmires de Araújo

; Lira, Hélio de Lucena

Matéria (Rio de Janeiro)

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2017, Volume 22 N. 1 elocation e11795

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

RESUMO O descarte inapropriado de resíduos das indústrias da cerâmica vermelha é bastante elevado. Um dos maiores desafios da atualidade é a investigação de processos para a obtenção de materiais alternativos, que permitam o emprego destes resíduos na fabricação de novos materiais. Este trabalho tem como objetivo estudar composições de massas argilosas a partir da incorporação de resíduo da indústria de cerâmica vermelha para uso em membranas cerâmicas tubulares. Foram estabelecidas duas composições de massa cerâmica; composição A (50% de resíduo) e composição B (70% de resíduo). As análises granulométricas das massas cerâmicas apresentaram um tamanho médio de partículas que prever membranas na escala de microfiltração. Outro fator observado está relacionado ao aumento da quantidade de resíduo, o mesmo, favoreceu a diminuição da plasticidade na massa cerâmica. Observou-se também um aumento na porosidade aparente, provavelmente pelo possível crescimento do número de poros maiores, decorrentes da temperatura elevada de sinterização e do próprio aumento da quantidade de resíduo.

ABSTRACT The inappropriate residue disposal of red ceramic industry is very high. Nowadays, one of the major challenges is the investigation of processes to obtain alternative materials, enabling the use of these residues to manufacture new materials. This work's objective is to study clayey masses' compositions starting from the residue incorporation of the red ceramic industry to be used in tubular ceramic membranes. Two compositions of ceramic masses were established, composition A (50% of residue) and composition B (70% of residue). Granulometric analysis of the ceramic masses presented an average size of particles, what indicates membranes in the microfiltration scale. Another observed factor is related to the increase of residue amount, what favored a decrease in the ceramic mass' plasticity. A rise in the apparent porosity was also observed, probably because of a possible growing in the bigger pores numbers, due to the sintering high temperature and the elevation of residue quantity itself.

https://doi.org/10.1590/s1517-707620170001.0127 1219 downloads

11.

MODELAGEM DO CRESCIMENTO E DA PRODUÇÃO DE POVOAMENTOS DEEucalyptus EM NÍVEL DE DISTRIBUIÇÃO DIAMÉTRICA UTILIZANDO ÍNDICE DE LOCAL1
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Castro, Renato Vinícius Oliveira

; Araújo, Raika Anairã Alves

; Leite, Helio Garcia

; Castro, Ana Flávia Neves Mendes

; Silva, Antoniomar

; Pereira, Reginaldo Sérgio

; Leal, Fabrício Assis

Revista Árvore

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feb 2016, Volume 40 N. 1 Pages 107 - 116

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

RESUMO A predição da produção de povoamentos florestais por classe diamétrica é de suma importância quando se tem por objetivo gerar multiprodutos da madeira. Assim, objetivou-se, neste trabalho, estimar a produção de um povoamento de clones do híbrido de Eucalyptus urophylla x Eucalyptus grandis por classe diamétrica, utilizando a variável índice de local (S). A classificação da capacidade produtiva de cada parcela foi feita por meio de curvas de índices de local, empregando-se os métodos da curva-guia e da equação das diferenças. Em seguida, ajustou-se a função densidade de probabilidade (f.d.p.) Weibull de dois parâmetros pelo método da máxima verossimilhança. Para a projeção dos parâmetros da f.d.p., utilizou-se um sistema de equações com inclusão da variável S. A avaliação do ajuste desse sistema foi feita por meio da análise dos gráficos de resíduos e das estatísticas de precisão: coeficiente de determinação ajustado (R2ajust) e erro-padrão da média relativo (Syx%). O ajuste foi realizado utilizando 80% das parcelas e as 20% restantes, utilizadas para validação. A classificação da capacidade produtiva por meio de índices de local foi eficiente pelos dois métodos avaliados, sendo selecionado o método da curva-guia devido à sua simplicidade e facilidade de aplicação. O sistema de equações com inclusão da variável índice de local (S) foi preciso na modelagem da distribuição diamétrica do povoamento analisado. A aplicabilidade do sistema de equações se mostrou bastante eficiente para três prognoses consecutivas.

ABSTRACT The prediction of the production of forest stands by diameter class has great importance when it aims to generate timber multiproduct. Keeping this in view, this study aimed to estimate the production of a stand of clones of hybrid Eucalyptus urophylla x Eucalyptus grandis by diameter class using the variable site index (S). The classification of the productive capacity of each plot was taken by site index curves using the methods of the guide curve and the difference equation. Then the Weibull probability density function (p.d.f.) of two parameters was adjusted by the maximum likelihood method. To project the parameters of the p.d.f., a system of equations was used with the inclusion of the variable S. The rating of system adjustment was made by analyzing the residual graphs, and accuracy statistics: adjusted coefficient of determination (R2adjust) and relative standard error of the mean (Syx%). The adjustment was performed using 80% of the plots and the remaining 20% were used for validation. The classification of productive capacity through site index was efficient by the two evaluated methods, but the guide-curve method was selected due to its simplicity and ease of application. The system of equations with inclusion of local index variable (S) was necessary for modeling the diameter distribution of the analyzed stand. The applicability of the equation system proved quite effective for three consecutive prognoses.

https://doi.org/10.1590/0100-67622016000100012 2838 downloads

12.

Efeito da natacao associada a diferentes tratamentos sobre o musculo soleo de ratos: estudo histologico e morfometrico
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Oliveira, Dean Rodrigues

; Pinho, Anna Carolina Azambuja

; Delise, Jaqueline Del Negri

; Nunes, Mariana Pereira

; Diniz, Luana Beatriz MPV

; Ribeiro Neto, Helio

; Santos, Helio Batista dos

; Oliveira, Vanessa Neves de

; Ribeiro, Rosy Iara Maciel de Azambuja

Revista Brasileira de Medicina do Esporte

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jan 2014, Volume 20 N. 1 Pages 74 - 77

Abstract: Pt En Es | Text: Pt En Es | PDF: Pt | PDF: En | PDF: Es

INTRODUÇÃO: O uso de suplementos ergogênicos farmacológicos e nutricionais cresce a cada dia no ambiente esportivo. A creatina e os esteroides anabólicos são os recursos ergogênicos mais procurados ultimamente. OBJETIVO: Avaliar as alterações histológicas e morfométricas do músculo sóleo de ratos que receberam suplementos e foram submetidos a treinamento físico (TF) de natação. MÉTODOS: Foram utilizados 50 ratos, distribuidos em cinco grupos: três não submetidos à atividade física (controles) e dois que receberam treinamento de natação (treinados). Um grupo controle recebeu apenas ração (grupo controle ração), dois grupos (um controle e outro treinado) receberam diariamente 3,3 mg de creatina por grama de dieta dissolvida em água aplicada oralmente via gavagem, e os outros dois grupos (um controle e outro treinado) receberam injeção intramuscular do esteroide anabolizante decanoato de nandrolona (Deca-durabolin(r) - Organon) 5 mg/kg duas vezes por semana. Os grupos treinados foram submetidos ao TF com duração de 60 min/sessão de segunda a sexta-feira por nove semanas, e foram sacrificados no final deste período. Após o sacrifício, o músculo sóleo foi retirado, fixado em formalina (10%) tamponada e incluído em parafina. Os cortes histológicos foram corados pela técnica de hematoxilina-eosina para avaliação de hiperplasia e hipertrofia muscular. Para análise dos dados aplicou-se a análise de variância ANOVA One-Way com post hoc de Tukey-Kramer com nível de significância de 5%. RESULTADOS: Foi demonstrado que a creatina associada ao exercício provavelmente aumente o espaço intersticial no músculo esquelético sem alterar o tamanho ou número de fibras musculares, enquanto que o anabolizante aumentou o número de fibras musculares por área de músculo analisada, embora nenhuma alteração tenha sido observada na área da fibra. CONCLUSÃO: O músculo de ratos submetidos ao treinamento de natação responde diferentemente frente ao tipo de recurso ergogênico utilizado.

INTRODUCTION: The use of pharmacologic and nutritional ergogenic supplements is growing every day in sports environment. Creatine and anabolic steroids are the most popular ergogenic resources used lately. OBJECTIVE: To evaluate the histological and morphometric changes of the soleus muscle of rats receiving supplements and submitted to physical training (swimming). METHODS: 50 rats were allocated into five groups: three did not undergo physical activity (controls) and two that received swimming training (trained). A control group received only rat chow (control chow group), two groups (one control and one trained) received 3.3mg of creatine per gram of diet dissolved in water daily applied orally via gavage, and the other two groups (control and other trained) received intramuscular injections of the anabolic steroid nandrolone decanoate (Deca-durabolin(r) - Organon) 5mg/kg twice weekly. The trained groups were submitted to the physical training 60min/day lasting from Monday to Friday for 9 weeks and were sacrificed at the end of the period. After sacrifice, the soleus muscle was removed, fixed in buffered formalin (10%) and embedded in paraffin. The histological sections were stained by hematoxylin-eosin for evaluation of muscle hyperplasia and hypertrophy. For data analysis we applied the One-Way ANOVA with post hoc Tukey-Kramer significance level of 5%. RESULTS: It was shown that creatine during exercise probably increase the interstitial space in skeletal muscle without changing the size or number of muscle fibers, whereas the anabolic agent increased the number of muscle fibers per muscle area examined, though no changes have been observed in the area of the fiber. CONCLUSION: The muscle of rats submitted to swimming training responds differently opposite type of ergogenic aid used.

INTRODUCCIÓN: El uso de suplementos ergogénicos farmacológicos y nutricionales crece, cada día, en el ambiente deportivo. La creatina y los esteroides anabólicos son los recursos ergogénicos más procurados en los últimos tiempos. OBJETIVO: Evaluar las alteraciones histológicas y morfométricas del músculo sóleo de ratones que recibieron suplementos y fueron sometidos a entrenamiento físico (EF) de natación. MÉTODOS: Se utilizaron 50 ratones, distribuidos en cinco grupos: tres de estos no sometidos a la actividad física (controles) y dos que recibieron entrenamiento de natación (entrenados). Un grupo de control recibió solamente ración (grupo de controle por ración), dos grupos (uno de control y otro entrenado) recibieron diariamente 3,3 mg de creatina, por gramo de dieta, disuelta en agua aplicada oralmente vía gavaje, y los otros dos grupos (uno de control y otro entrenado) recibieron inyección intramuscular del esteroide anabolizante decanoato de nandrolona (Deca-durabolin(r) - Organon), 5 mg/kg dos veces por semana. Los grupos entrenados fueron sometidos al EF, con duración de 60 min/sesión, de lunes a viernes durante nueve semanas, y fueron sacrificados al final de este período. Después del sacrificio, el músculo sóleo fue retirado, fijado en formalina (10%) tamponada e insertado en parafina. Los cortes histológicos fueron coloridos mediante la técnica de hematoxilina-eosina para evaluación de hiperplasia e hipertrofia muscular. Para el análisis de los datos se aplicó el análisis de variancia ANOVA One-Way con post hoc de Tukey-Kramer, con nivel de significancia de 5%. RESULTADOS: Se demostró que la creatina, vinculada al ejercicio, aumenta probablemente el espacio intersticial en el músculo esquelético, sin alterar el tamaño ni el número de fibras musculares, mientras que el anabolizante aumentó la cantidad de fibras musculares por área de músculo que se analizó, aunque no se observó cualquier alteración en el área de la fibra. CONCLUSIÓN: El músculo de ratones, sometidos al entrenamiento de natación, responde de manera diferente frente al tipo de recurso ergogénico utilizado.

https://doi.org/10.1590/S1517-86922014000100015 4933 downloads Cited 1 time in SciELO

13.

Morphogenesis in guinea grass pastures under rotational grazing strategies
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Montagner, Denise Baptaglin

; Nascimento Júnior, Domicio do

; Sousa, Braulio Maia de Lana

; Vilela, Hélio Henrique

; Silveira, Márcia Cristina Teixeira da

; Euclides, Valéria Pacheco Batista

; Silva, Sila Carneiro da

; Carloto, Marciele Neves

Revista Brasileira de Zootecnia

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apr 2012, Volume 41 N. 4 Pages 883 - 888

Abstract: En | Text: En | PDF: En

This study was conducted in order to evaluate the morphogenetic and structural characteristics of guinea grass cv. Mombasa under three post-grazing heights (intense - 30 cm, lenient - 50 cm and variable - 50 in spring-summer and 30 cm in autumn-winter) when sward light interception reached 95% during regrowth. Post-grazing heights were allocated to experimental units (0.25 ha) in a completely randomized block design with three replications. Post-grazing heights affected only leaf elongation rate and the number of live leaves. Pastures managed with variable post-grazing height showed higher leaf elongation rate in the summer of 2007. This management strategy also resulted in a higher number of live leaves. During the spring of 2006, plants showed lower leaf elongation rate, leaf appearance rate and number of live leaves, and greater phyllochron and leaf lifespan. In contrast, during the summer of 2007, the leaf appearance rate, leaf elongation rate, number of live leaves, and final leaf length were greater while phyllochron, stem elongation rate, and leaf senescence rate were lower. The management of the guinea grass cv. Mombasa with intense or variable post-grazing height throughout the year seems to represent an interesting management target, in terms of leaf appearance rate and number of live leaves.

2546 downloads Cited 2 times in SciELO

14.

Tillering dynamics in pastures of guinea grass subjected to grazing severities under intermittent stocking
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Montagner, Denise Baptaglin

; Nascimento Júnior, Domicio do

; Vilela, Hélio Henrique

; Sousa, Braulio Maia de Lana

; Euclides, Valéria Pacheco Batista

; Silva, Sila Carneiro da

; Carloto, Marciele Neves

Revista Brasileira de Zootecnia

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mar 2012, Volume 41 N. 3 Pages 544 - 549

Abstract: En | Text: En | PDF: En

This experiment was carried out to analyze the tillering dynamics of the species Panicum maximum cv. Mombaca subjected to three post-grazing heights: residue of 30 cm (30); residue of 50 cm (50); and residue of 50 cm during spring and summer, lowered to 40 cm in the first fall season grazing and to 30 cm in the following grazing cycle, resuming to 50 cm after the first grazing of the following spring season (50-30). Grazings were initiated whenever the swards intercepted 95% of the incident light. The post-grazing heights were allocated in the experimental units in a completely randomized block design with three replications. The density of basal tillers did not vary between the residual heights evaluated. Swards managed with variable residual height (50-30) presented higher rates of appearance and mortality of basal tillers during the summer of 2007, indicating high tiller renovation. Regardless of the post-grazing height evaluated, lower rates of appearance of basal tillers were found in the spring of 2006. The stability index of guinea grass cv. Mombaca was close to 1.0 throughout the experimental period. Swards managed with variable post-grazing present structural changes able to improve the regrowth vigor, which may be important to maximize the use of the forage species in the production system.

1761 downloads Cited 6 times in SciELO

15.

Morphogenetic and structural characteristics of tillers of guinea grass of different age and grazing severities
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Montagner, Denise Baptaglin

; Nascimento Júnior, Domicio do

; Sousa, Braulio Maia de Lana

; Vilela, Hélio Henrique

; Euclides, Valéria Pacheco Batista

; Silva, Sila Carneiro da

; Sbrissia, André Fischer

; Carloto, Marciele Neves

Revista Brasileira de Zootecnia

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oct 2011, Volume 40 N. 10 Pages 2105 - 2110

Abstract: En | Text: En | PDF: En

The objective of this research was to evaluate the effects of tiller age on morphogenic and structural characteristics of guinea grass cv. Mombaca subjected to intermittent stocking and three stubble heights: 30 cm, 50 cm and 50-30 cm. Stubble heights were assigned to experimental units in a completely randomized block design with three replicates. Grazing was performed when canopy intercepted 95% of light incidence. Leaf appearance rate, leaf elongation rate and number of live leaves per tiller were higher in the summer when compared with the winter. Contrarily, stem elongation rate, phyllochron and leaf lifespan were lower in the summer when compared with the winter. During the summer, young tillers had higher leaf appearance and elongation rates when compared with the older ones. Young and mature tillers had the highest values of live leaves per tiller in the summer. There was no difference between summer and winter for the final length of leaf blade between tillers of the same age, except in mature tillers, which had higher final leaf length during the summer. Senescence rate of leaves was higher in young tillers, followed by mature and old tillers. Age of tiller affects morphogenic and structural characteristics of pasture, showing that young tillers have better growth compared with mature and old tillers

2085 downloads Cited 7 times in SciELO

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