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1.
Polymers (Basel) ; 15(11)2023 May 30.
Article in English | MEDLINE | ID: mdl-37299312

ABSTRACT

In recent years, polymeric materials have been gaining prominence in studies of controlled release systems to obtain improvements in drug administration. These systems present several advantages compared with conventional release systems, such as constant maintenance in the blood concentration of a given drug, greater bioavailability, reduction of adverse effects, and fewer dosages required, thus providing a higher patient compliance to treatment. Given the above, the present work aimed to synthesize polymeric matrices derived from polyethylene glycol (PEG) capable of promoting the controlled release of the drug ketoconazole in order to minimize its adverse effects. PEG 4000 is a widely used polymer due to its excellent properties such as hydrophilicity, biocompatibility, and non-toxic effects. In this work, PEG 4000 and derivatives were incorporated with ketoconazole. The morphology of polymeric films was observed by AFM and showed changes on the film organization after drug incorporation. In SEM, it was possible to notice spheres that formed in some incorporated polymers. The zeta potential of PEG 4000 and its derivatives was determined and suggested that the microparticle surfaces showed a low electrostatic charge. Regarding the controlled release, all the incorporated polymers obtained a controlled release profile at pH 7.3. The release kinetics of ketoconazole in the samples of PEG 4000 and its derivatives followed first order for PEG 4000 HYDR INCORP and Higuchi for the other samples. Cytotoxicity was determined and PEG 4000 and its derivatives were not cytotoxic.

2.
Sci Rep ; 10(1): 22312, 2020 12 18.
Article in English | MEDLINE | ID: mdl-33339861

ABSTRACT

Plants may contain beneficial or potentially dangerous substances to humans. This study aimed to prepare and evaluate a new drug delivery system based on a glass-ionomer-Brazilian pepper extract composite, to check for its activity against pathogenic microorganisms of the oral cavity, along with its in vitro biocompatibility. The ethanolic Brazilian pepper extract (BPE), the glass-ionomer cement (GIC) and the composite GIC-BPE were characterized by scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and thermal analysis. The BPE compounds were identified by UPLC-QTOF-MS/MS. The release profile of flavonoids and the mechanical properties of the GIC-BPE composite were assessed. The flavonoids were released through a linear mechanism governing the diffusion for the first 48 h, as evidenced by the Mt/M∞ relatively to [Formula: see text], at a diffusion coefficient of 1.406 × 10-6 cm2 s-1. The ATR-FTIR analysis indicated that a chemical bond between the GIC and BPE components may have occurred, but the compressive strength of GIC-BPE does not differ significantly from that of this glass-ionomer. The GIC-BPE sample revealed an ample bacterial activity at non-cytotoxic concentrations for the human fibroblast MRC-5 cells. These results suggest that the prepared composite may represent an alternative agent for endodontic treatment.


Subject(s)
Anacardiaceae/chemistry , Glass Ionomer Cements/chemical synthesis , Mouth/drug effects , Plant Extracts/chemistry , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Brazil , Compressive Strength , Fruit/chemistry , Glass Ionomer Cements/chemistry , Glass Ionomer Cements/pharmacology , Humans , Materials Testing , Microscopy, Electron, Scanning , Mouth/chemistry , Mouth/microbiology , Plant Extracts/pharmacology , Spectroscopy, Fourier Transform Infrared
3.
Int J Sports Med ; 36(13): 1069-75, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26258825

ABSTRACT

The contribution of chronological age, skeletal age (Fels method) and body size to variance in peak velocity derived from the Carminatti Test was examined in 3 competitive age groups of Brazilian male soccer players: 10-11 years (U-12, n=15), 12-13 years (U-14, n=54) and 14-15 years (U-16, n=23). Body size and soccer-specific aerobic fitness were measured. Body composition was predicted from skinfolds. Analysis of variance and covariance (controlling for chronological age) were used to compare soccer players by age group and by skeletal maturity status within of each age group, respectively. Relative skeletal age (skeletal age minus chronological age), body size, estimated fat-free mass and performance on the Carminatti Test increased significantly with age. Carminatti Test performance did not differ among players of contrasting skeletal maturity status in the 3 age groups. Results of multiple linear regressions indicated fat mass (negative) and chronological age (positive) were significant predictors of peak velocity derived from the Carminatti Test, whereas skeletal age was not a significant predictor. In conclusion, the Carminatti Test appears to be a potentially interesting field protocol to assess intermittent endurance running capacity in youth soccer programs since it is independent of biological maturity status.


Subject(s)
Athletic Performance , Physical Endurance/physiology , Skeleton/physiology , Soccer , Adolescent , Age Determination by Skeleton , Anthropometry , Athletes , Body Composition , Body Size , Brazil , Child , Humans , Male
4.
Int J Sports Med ; 36(4): e5, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25958939
5.
Rev. andal. med. deporte ; 7(4): 155-161, dic. 2014. ilus, tab
Article in Portuguese | IBECS | ID: ibc-129982

ABSTRACT

Objetivo. Analisar o consumo de oxigênio (VO2) acumulado e o tempo em que o VO2 é mantido (TMcg) em elevados valores durante o exercício realizado na máxima fase estável de lactato (MLSS) determinada de forma contínua (MLSScon) e intermitente (MLSSint) até à exaustão. Método. Catorze ciclistas treinados realizaram um teste incremental máximo no cicloergômetro; 2‐5 testes contínuos e 2‐4 testes intermitentes, para determinação da MLSScon e MLSSint, respectivamente; por fim mais 2 testes até a exaustão (TTE) (contínuo e intermitente), conduzidos nas respectivas cargas de MLSS. Resultados. O TTE contínuo foi significativamente menor do que o TTE intermitente (54,7 ± 10,9 vs. 67,8 ± 14,3, respectivamente; p = 0,001). O VO2 da carga (VO2cg) foi significantemente maior na condição intermitente (p < 0,05), em ambas as situações (MLSS e TTE). Por outro lado, o TMcg e o VO2 acumulado na carga (VO2ACcg) foram maiores na condição contínua (p < 0,0001), em ambas as situações. O total de VO2 acumulado (VO2ACt) foi similar entre as condições contínuas e intermitentes (104,7 ± 8,7 L vs. 103,9 ± 41,1 L para a MLSS e 193,8 ± 41,1 L vs. 226,4 ± 53,0 L para o TTE, respectivamente). Conclusão. Os exercícios contínuo e intermitente realizados com a mesma duração ou até a exaustão, e em condições metabólicas similares, apresentam valores de VO2ACt similares, embora o TMcg e o VO2ACcg sejam inferiores no exercício intermitente (AU)


Objetivo. Analizar el consumo de oxígeno (VO2) acumulado y el tiempo en que el VO2 es mantenido (TMcg) en valores elevados, durante el ejercicio realizado en la máxima fase estable de lactato (MLSS), determinada de forma continua (MLSScon) e intermitente (MLSSint) hasta el agotamiento. Método. Catorce ciclistas entrenados realizaron un test incremental máximo en el cicloergómetro; 2‐5 test continuos y 2‐4 test intermitentes, para determinación de la MLSScon y MLSSint, respectivamente; por último realizaron 2 test hasta el agotamiento (TTE) (continuo e intermitente), a las respectivas cargas de MLSS. Resultados. El TTE continuo fue significativamente menor que el TTE intermitente (54,7 ± 10,9 vs. 67,8 ± 14,3, respectivamente; p = 0,001). El VO2 de la carga (VO2cg) fue significativamente mayor en la condición intermitente (p < 0,05), en ambas situaciones (MLSS y TTE). Por otro lado, el TMcg y el VO2 acumulado en la carga (VO2ACcg) fueron mayores en la condición continua (p < 0,0001), en ambas las situaciones. El total de VO2 acumulado (VO2ACt) fue similar entre las condiciones continuas e intermitentes (104,7 ± 8,7 L vs. 103,9 ± 41,1 L para a MLSS y 193,8 ± 44,1 L vs. 226,4 ± 53,0 L para el TTE, respectivamente). Conclusión. Los ejercicios continuo e intermitente realizados con la misma duración o hasta el agotamiento, y en condiciones metabólicas similares presentan valores de VO2ACt similares, aunque el TMcg y el VO2ACcg sean inferiores en el ejercicio intermitente (AU)


Objective. The aim of this study was to analyse the accumulated oxygen uptake (VO2), as well the maintained time (TMcg) at high levels during a maximal lactate steady state (MLSS) exercise, determined in continuous (MLSScon) and intermittent (MLSSint) modes, until exhaustion. Method. Fourteen trained cyclists performed an incremental maximal testing; 2‐5 continuous and 2‐4 intermittent constant workload trials, in order to identify the MLSScon and MLSSint, respectively; two tests until exhaustion (TTE) (continuous and intermittent) were conducted using their respective MLSS workloads. Results. The continuous TTE was significantly lower than TTE at intermittent protocol (54.7 ± 10.9 vs. 67.8 ± 14.3 min; p = 0.001). The VO2 at target workload (VO2cg) was higher at intermittent exercise (p < 0.05), at both situations (MLSS and TTE). On the other hand, TMcg and the VO2 accumulated in MLSS workloads (VO2ACcg) were higher during continuous mode (p < 0.0001), at both situations. The total VO2 accumulated (VO2ACt) was similar between intermittent and continuous cycling (MLSS: 104.7 ± 8.7 L vs. 103.9 ± 41.1 L and TTE: 193.8 ± 41.1 L vs. 226.4 ± 53.0 L, respectively). Conclusion. When MLSS continuous and intermittent were performed with same duration or until exhaustion, the VO2ACt was similar, although the TMcg and VO2ACcg were smaller during intermittent exercise (AU)


Subject(s)
Humans , Male , Adult , Oxygen Consumption/physiology , Bicycling/classification , Bicycling/physiology , Bicycling/trends , Physical Exertion/physiology , Lactic Acid/analysis , Lactic Acid/blood , Kinetics , Metabolism/physiology , Sports/standards , Sports/trends , Body Mass Index , Helsinki Declaration , Experimental Development
6.
Rev. andal. med. deporte ; 7(4): 162-169, dic. 2014. tab
Article in Portuguese | IBECS | ID: ibc-129983

ABSTRACT

A patinação de velocidade in‐line é uma modalidade que está crescendo nos últimos anos, contudo, ainda é pouco estudada devido a dificuldade de ser reproduzida em laboratório. Neste artigo, foi realizada uma revisão bibliográfica sobre o conhecimento, com base em investigações prévias desta modalidade esportiva. As consultas foram realizadas nas bases de dados LILACS, SCOPUS, PubMed, SciELO, Science Direct, Ovid e Google. Foram incluídos apenas estudos com humanos, publicados em inglês, português, italiano e francês sem restrição de ano de publicação. Do total de 143 artigos, 27 abordaram sobre patinação in-line, destes, 14 investigaram as variáveis fisiológicas, 8 as variáveis biomecânicas e 5 investigaram ambas. Seis estudos compararam as respostas fisiológicas durante a patinação com protocolos de corrida ou ciclismo; somente 2 verificaram a validade de um protocolo específico, para determinar indiretamente a capacidade aeróbica de patinadores de velocidade in-line. Os resultados dos estudos foram controversos e inconsistentes, revelando que existe a necessidade de investigar profundamente este esporte (AU)


El patinaje de velocidad sobre ruedas es una modalidad que ha crecido en los últimos años, pero que aún está poco estudiada debido a la dificultad de ser reproducida en laboratorio. En este artículo, fue realizada una revisión bibliográfica sobre el estado del conocimiento con base en las investigaciones ya realizadas acerca de esta modalidad deportiva. Fueron consultadas las bases de datos LILACS, SCOPUS, PubMed, SciELO, Science Direct, Ovid y Google. Se incluyeron estudios con humanos, publicados en inglés, portugués, italiano y francés, sin restricciones de año de publicación. De un total de 143 artículos, 27 tratan del patinaje sobre ruedas; de estos, 14 investigaron las variables fisiológicas, 8 las biomecánicas y 5 investigaron ambas variables. Seis estudios compararon la respuesta fisiológica durante el patinaje con protocolos de carrera o ciclismo; solamente 2 verificaron la validez de un protocolo específico para determinar indirectamente la capacidad aeróbica de los patinadores de velocidad sobre ruedas. Se pudo verificar que los resultados de los estudios fueron controvertidos e inconsistentes, lo cual revela que existe la necesidad de investigar más a fondo este deporte (AU)


The use of in‐line skates has become popular in recent years for recreational and conditioning purposes. Nevertheless, in‐line speed skating is not widely investigated yet, due to the difficulty to conduct specific tests under laboratory conditions. This study aimed to investigate the state of the art of in‐line speed skating researches. A systematic literature review on LILACS, Scopus, PubMed, SciELO, Science Direct, Ovid and Google was performed, including studies on human, which were published in English, Portuguese, Italian or French, with no restrictions related to the year of publication. From a total of 143 articles with skating, 27 investigated the in‐line skating, of which 14 investigated physiological variables, eight investigated biomechanical variables, and five investigated both variables. Six studies compared the physiological response during skating with running or cycling protocols and only two verified the validity of a specific protocol to indirectly determine the aerobic capacity of in‐line speed skaters. Finally, the results found were controversial and inconsistent, showing the need of more investigations about this sport (AU)


Subject(s)
Humans , Male , Female , Young Adult , Adult , Skating/classification , Skating/physiology , Psychomotor Performance/physiology , Anaerobic Threshold/physiology , Athletic Performance/physiology , Metabolism/physiology , Bibliometrics , Lactic Acid/analysis , Lactic Acid/blood , Sports/physiology
7.
Rev. andal. med. deporte ; 7(2): 83-89, jun. 2014. tab
Article in Portuguese | IBECS | ID: ibc-123915

ABSTRACT

Objetivo: O presente estudo teve como objetivo analisar os efeitos de diferentes métodos de treinamento intervalado (TI) nos parâmetros fisiológicos e no desempenho de ciclistas competitivos. Método: A classificação dos métodos de TI foram: a) sub-máximo (TIsub), b) máximo (TImax) e c ) supra-máximo (TIsup). A estratégia de busca incluiu os seguintes termos: treinamento intervalado, treinamento intervalado em ciclistas, treinamento intervalado de alta intensidade, treinamento intervalado de alta intensidade em ciclistas e sprint. Foram consultadas as seguinte bases de dados: PubMed, Google Scholar e SPORTDiscus. Para isso, foi realizada uma pesquisa entre julho de 2011 e fevereiro de 2012. Resultados: Dentre as diferentes metodologias de TI em ciclistas competitivos, todos os métodos foram suficientes para demonstrar melhorias na potência aeróbia máxima (Pmax), consumo máximo de oxigênio (VO2max), limiares fisiológicos, tempo de exaustão (Tlim) e contra-relógio de 40 km no ciclismo (CR40km ) em ciclistas competitivos. Conclusão: Portanto, os três métodos de TI demonstraram que são necessárias de 6-8 sessões de treino durante um período de 4-6 semanas para se obter ganhos nas variáveis fisiológicas e na performance em ciclistas competitivos


Objetivo. En la presente investigación hemos planteado como objetivo analizar los efectos de diferentes métodos de entrenamiento de intervalos (EI) en los parámetros de la capacidad fisiológica y el desempeño de los ciclistas de competición. Método. La clasificación de los métodos de EI es: a) sub-máxima (EIsub), b) máxima (EImax), y c) supramáxima (EIsup). La estrategia de búsqueda incluyó los términos siguientes: entrenamiento de intervalos, entrenamiento de intervalos en el ciclismo, entrenamiento de intervalo de alta intensidad, entrenamiento de intervalo de alta intensidad en el ciclismo y sprint. Para este fin, se realizó una búsqueda entre julio de 2011 y febrero de 2012 en las bases de datos: PubMed y Google Scholar SPORTDiscus. Resultados. Entre las diferentes metodologías de EI en ciclistas de competición, todos los métodos fueron suficientes para demostrar mejoras de la potencia aeróbica máxima (Pmax), el consumo máximo de oxígeno (VO2max), los umbrales fisiológicos, tiempo hasta el agotamiento (Tlim) y la prueba de 40 km de contrarreloj de ciclismo (CR40km). Conclusión. Los tres métodos de EI mostraron que es necesario 6-8 sesiones de entrenamiento durante un período de 4-6 semanas para que los ciclistas entrenados mejoraron las variables fisiológicas y de rendimiento (AU)


Objective. The aim of this study was to analyze the effects of different methods of interval training (IT) on physiological variables and performance in competitive cyclists. Method. The classification of the IT methods were: a) sub-maximal (ITsub), b) high (ITmax) and c) supramaximum (ITsup). The search strategy included the following terms: interval training, interval training on cycling, high intensity interval training, high intensity interval training in cycling and sprint. We choose for the followed databases: PubMed, Google Scholar and SPORTDiscus. For this purpose, a search were in a period between July 2011 and February 2012. Results. The different methods of IT increased maximal aerobic power (Pmax), maximum oxygen consumption (VO2max), physiological thresholds, time to exhaustion (Tlim) and 40-km cycling time trial CR40km ) in competitive cyclists. Conclusion. Therefore, the three methods of IT showed that 6-8 sessions of training during 4-6 weeks isnecessary to improve physiological variables and cycling performance in competitive cyclists (AU)


Subject(s)
Humans , Bicycling/physiology , Physical Education and Training , Athletic Performance/physiology , Exercise/physiology , Exercise Movement Techniques/methods
8.
Vis Neurosci ; 18(2): 245-51, 2001.
Article in English | MEDLINE | ID: mdl-11417799

ABSTRACT

Adult albino mammals have specific retinal defects, including reduced numbers of rod photoreceptors. To examine when this rod deficit arises and whether it exists in nonmammalian albinos, we have used absorbance spectrophotometry to measure photopigment levels in dark-adapted eyes taken from three groups of pigmented and albino animals: adult rodents (rats and mice), developing rats, and mature Xenopus frogs. Rhodopsin concentrations were consistently and significantly reduced in mammalian albinos compared to their wild-type counterparts from before the time of eye opening, but photopigment levels were similar in frogs of both pigmentation phenotypes. The results strongly suggest that deficits in the rod cell population arise early in development of the mammalian albino retina, but do not generalize to nonmammalian mutants lacking retinal melanin.


Subject(s)
Albinism, Ocular/metabolism , Retinal Rod Photoreceptor Cells/metabolism , Rhodopsin/metabolism , Animals , Animals, Newborn , Dark Adaptation , Female , Male , Mice , Mice, Inbred CBA , Microspectrophotometry , Rats , Rats, Mutant Strains , Rats, Wistar , Xenopus laevis
9.
J Sci Med Sport ; 3(1): 1-8, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10839223

ABSTRACT

The objectives of this study were to verify the effects of wet suits (WS) on the performance during 1500m swimming (V1500), on the velocity corresponding to the anaerobic threshold (VAT) and on the drag force (AD) as well as its coefficient (Cx). 19 swimmers randomly completed the following protocols on different days (with and without WS): 1) maximal performance of 1500m swimming; 2) VAT in field test, with fixed concentration of blood lactate (4 mM) and 3) determination of hydrodynamic indices (AD and Cx). The results demonstrated significant differences (p < 0.05) in the VAT (1.27 +/- 0.09; 1.21 +/- 0.06 m.s-1), and in the V1500 (1.21 +/- 0.08; 1.17 +/- 0.08 m.s-1), with and without WS, respectively. However the AD, and its Cx did not present significant differences (p>0.05) for the respective maximal speeds of swimming. In summary, we can conclude that WS allows swimmers to reach greater speeds in both, long- and short-course swims. This improvement can be related to the decrease of the AD, since with higher speeds (with WS) the subjects presented the same resistance, as they did when compared to speeds without a WS. Moreover, these data suggest that the methodology used in this study to determine the Cx is unable to detect the improvement caused by WS.


Subject(s)
Protective Clothing , Swimming/physiology , Adult , Anaerobic Threshold , Analysis of Variance , Biomechanical Phenomena , Female , Humans , Lactic Acid/blood , Male , Models, Theoretical , Psychomotor Performance
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