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SUMMARY: Spinal cord regeneration after mechanical injury is one of the most difficult biomedical problems. This article evaluates the effect of poly(N-[2-hydroxypropyl]-methacrylamide) hydrogel (PHPMA-hydrogel) on spinal cord regeneration in young rats after lateral spinal cord hemi-excision (laceration) at the level of segments T12-T13 (TrGel group). The locomotor function score (FS) and the paretic hindlimb spasticity score (SS) were assessed according to Basso-Beattie-Bresnahan (BBB) and Ashworth scales, respectively, and compared to a group of animals with no matrix implanted (Tr group). Regeneration of nerve fibers at the level of injury was evaluated at ~5 months after spinal cord injury (SCI). One week after the SCI induction, the FS on the BBB scale was 0.9±0.5 points in the Tr group and 3.6±1.2 points in the TrGel group. In the Tr group, the FS in 5 months was significantly lower than in 2 weeks after SCI, while no significant changes in FS were detected in the TrGel group over the entire observation period. The final FS was 0.8±0.3 points in the Tr group and 4.5±1.8 points in the TrGel group. No significant changes in SS have been observed in the TrGel group throughout the experiment, while the Tr group showed significant increases in SS at 2nd week, 6th week, 3th month and 5th month. The SS in 5 months was 3.6±0.3 points on the Ashworth scale in the Tr group and 1.8±0.7 points in the TrGel group. Throughout the observation period, significant differences in FS between groups were observed only in 5 weeks after SCI, whereas significant differences in SS were observed in 2, 3 and 6-8 weeks post-injury. Glial fibrous tissue containing newly formed nerve fibers, isolated or grouped in small clusters, that originated from the surrounding spinal cord matter have been found between the implanted hydrogel fragments. In conclusion, PHPMA-hydrogel improves recovery of the hindlimb locomotor function and promotes regenerative growth of nerve fibers. Further research is needed to clarify the mechanism of this PHPMA-hydrogel effect.

RESUMEN: La regeneración de la médula espinal después de una lesión mecánica es uno de los problemas biomédicos más difíciles. Este artículo evalúa el efecto del hidrogel de poli (N- [2-hidroxipropil] -metacrilamida) (PHPMA-hidrogel) sobre la regeneración de la médula espinal en ratas jóvenes después de la hemiescisión lateral de la médula espinal (lesión) a nivel de los segmentos T12 - T13 (Grupo TrGel). La puntuación de la función locomotora (FS) y la puntuación de espasticidad parética de las patas traseras (SS) se evaluaron de acuerdo con las escalas de Basso- Beattie-Bresnahan (BBB) y Ashworth, respectivamente, y se compararon con un grupo de animales sin matriz implantada (grupo Tr). Se evaluó la regeneración de las fibras nerviosas al nivel de la lesión ~ 5 meses después de la lesión de la médula espinal (LME). Una semana después de la inducción de SCI, el FS en la escala BBB fue 0,9 ± 0,5 puntos en el grupo Tr y 3,6 ± 1,2 puntos en el grupo TrGel. En el grupo Tr, el FS en 5 meses fue significativamente menor que en 2 semanas después de SCI, mientras que no se detectaron cambios significativos en FS en el grupo TrGel durante el período de observación. El FS final fue de 0,8 ± 0,3 puntos en el grupo Tr y de 4,5 ± 1,8 puntos en el grupo TrGel. No se han obser- vado cambios significativos en SS en el grupo TrGel durante el experimento, mientras que el grupo Tr mostró aumentos significativos en SS en la 2ª semana, 6ª semana, 3º mes y 5º mes. La SS en 5 meses fue de 3,6 ± 0,3 puntos en la escala de Ashworth en el grupo Tr y de 1,8 ± 0,7 puntos en el grupo TrGel. A lo largo del período de observación, se observaron diferencias significativas en FS entre los grupos solo en 5 semanas después de la LME, mientras que se observaron diferencias significativas en SS en 2, 3 y 6-8 semanas después de la lesión. Entre los fragmentos de hidrogel implantados se observó tejido fibroso glial que contenía fibras nerviosas recién formadas, aisladas o agrupadas en pequeños grupos, que se originaban a partir de la materia de la médula espinal circundante. En conclusión, PHPMA-hydrogel mejora la recuperación de la función locomotora de las patas traseras y promueve el crecimiento regenerativo de las fibras nerviosas. Se requieren más estudios para aclarar el mecanismo del efecto de hidrogel PHPMA.

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Purpose: This study aimed to elaborate a hydrogel constituted by carboxymethyl chitosan (CMC), hyaluronic acid (HA) and silver (Ag) and to evaluate its healing effect on partial-thickness burn wounds experimentally induced in rats. Methods: CMC was obtained by chitosan reacting with monochloroacetic acid. The carboxymethylation was confirmed by Fourier-transform infrared spectroscopy and hydrogen nuclear magnetic resonance (NMR). Scanning electron microscopy was used to determine the morphological characteristics of chitosan and CMC. After the experimental burn wound induction, the animals (n = 126) were treated with different CMC formulations, had their occlusive dressings changed daily and were followed through 7, 14 and 30 days. Morphometric, macroscopic and microscopic aspects and collagen quantification were evaluated. Results: Significative wound contraction, granulation tissue formation, inflammatory infiltration and collagen fibers deposit throughout different phases of the healing process were observed in the CMC hydrogels treated groups. Conclusion: The results showed that, in the initial phase of the healing process, the most adequate product was the CMC/HA/Ag association, while in the other phases the CMC/HA association was the best one to promote the healing of burn wounds.(AU)

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The purpose is to estimate the oxygen diffusion coefficient and the relaxation time of the cornea with respect to the oxygen tension at the cornea-tears interface. Both findings are discussed. From the experimental data provided by Bonanno et al., the oxygen tension measurements in vivo for human cornea-tears-contact lens (CL), the relaxation time of the cornea, and their oxygen diffusion coefficient were obtained by numerical calculation using the Monod-kinetic model. Our results, considering the relaxation time of the cornea, observe a different behavior. At the time less than 8 s, the oxygen diffusivity process is upper-diffusive, and for the relaxation time greater than 8 s, the oxygen diffusivity process is lower-diffusive. Both cases depend on the partial pressure of oxygen at the entrance of the cornea. The oxygen tension distribution in the cornea-tears interface is separated into two different zones: one for conventional hydrogels, which is located between 6 and 75 mmHg, with a relaxation time included between 8 and 19 s, and the other zone for silicone hydrogel CLs, which is located at high oxygen tension, between 95 and 140 mmHg, with a relaxation time in the interval of 1.5-8 s. It is found that in each zone, the diffusion coefficient varies linearly with the oxygen concentration, presenting a discontinuity in the transition of 8 s. This could be interpreted as an aerobic-to-anaerobic transition. We attribute this behavior to the coupling formalism between oxygen diffusion and biochemical reactions to produce adenosine triphosphate. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:14-21, 2020.

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A alface é uma hortaliça bastante exigente em água, o que pode limitar sua produção em regiões com carência hídrica. Assim, o uso de tecnologias que permitam a maximização do uso da água nessas áreas se faz necessária. Nesse sentido, objetivou-se avaliar o crescimento e produção da alface utilizando diferentes reposições hídricas e polímero hidroretentor. O experimento foi conduzido em casa de vegetação em delineamento em blocos com tratamentos ao acaso, utilizando-se esquema fatorial 4 x 2 + 2, referentes as seguintes lâminas de irrigação (100%; 80%; 60%; 40% da capacidade de campo), e dois volumes de polímero hidroretentor (50 e 25 mL por planta), além de duas testemunhas, com quatro repetições. Foram determinadas a altura da planta; diâmetro da cabeça; número de folhas por planta; massa fresca e massa da matéria seca da parte aérea (caule + folhas). Observou-se efeito da lâmina de irrigação sob todas as características analisadas, no entanto, não se registrou efeito significativo das doses de polímero hidroretentor. A alface apresenta maior crescimento e produtividade com a lâmina de água de 100% da capacidade de campo.

Lettuce is a very demanding vegetable in water, which may limit its production in regions with water shortage. Thus, the use of technologies that maximize the use of water in these areas is necessary. In this sense, the objective was to evaluate the growth and yield of lettuce using different water replacements and hydroretentor polymer. The experiment was carried out in a greenhouse in a randomized block design using a 4 x 2 + 2 factorial scheme, referring to the following irrigation depths (100%; 80%; 60%; 40% of field capacity). ), and two volumes of hydroretentor polymer (50 and 25 mL per plant), plus two controls, with four replications. Plant height was determined; head diameter; number of leaves per plant; fresh mass and dry matter mass of shoot (stem+ leaves). Irrigation depth effect was observed under all the characteristics analyzed, however, there was no significant effect of hydroretentor polymer doses. Lettuce has higher growth and productivity with the water depth of 100% of field capacity.

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A alface é uma hortaliça bastante exigente em água, o que pode limitar sua produção em regiões com carência hídrica. Assim, o uso de tecnologias que permitam a maximização do uso da água nessas áreas se faz necessária. Nesse sentido, objetivou-se avaliar o crescimento e produção da alface utilizando diferentes reposições hídricas e polímero hidroretentor. O experimento foi conduzido em casa de vegetação em delineamento em blocos com tratamentos ao acaso, utilizando-se esquema fatorial 4 x 2 + 2, referentes as seguintes lâminas de irrigação (100%; 80%; 60%; 40% da capacidade de campo), e dois volumes de polímero hidroretentor (50 e 25 mL por planta), além de duas testemunhas, com quatro repetições. Foram determinadas a altura da planta; diâmetro da cabeça; número de folhas por planta; massa fresca e massa da matéria seca da parte aérea (caule + folhas). Observou-se efeito da lâmina de irrigação sob todas as características analisadas, no entanto, não se registrou efeito significativo das doses de polímero hidroretentor. A alface apresenta maior crescimento e produtividade com a lâmina de água de 100% da capacidade de campo. (AU)

Lettuce is a very demanding vegetable in water, which may limit its production in regions with water shortage. Thus, the use of technologies that maximize the use of water in these areas is necessary. In this sense, the objective was to evaluate the growth and yield of lettuce using different water replacements and hydroretentor polymer. The experiment was carried out in a greenhouse in a randomized block design using a 4 x 2 + 2 factorial scheme, referring to the following irrigation depths (100%; 80%; 60%; 40% of field capacity). ), and two volumes of hydroretentor polymer (50 and 25 mL per plant), plus two controls, with four replications. Plant height was determined; head diameter; number of leaves per plant; fresh mass and dry matter mass of shoot (stem+ leaves). Irrigation depth effect was observed under all the characteristics analyzed, however, there was no significant effect of hydroretentor polymer doses. Lettuce has higher growth and productivity with the water depth of 100% of field capacity.(AU)

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The incorporation of the hydrogel into the substrate used in the forest nursery promotes improvements in its physical-chemical attributes. However, several factors influence the hydrogel efficiency, such as the increase of salts, promoted by fertilizer of the substrate. Therefore, this study aimed to evaluate the effects of the incorporation of fertilizer levels and hydrogel doses on the physical-chemical attributes of a substrate to produce forest seedlings. Different levels of basic fertilizer commonly used in the nursery (100%, 50% and 0%) and different doses of the hydrogel (0, 1, 2 and 3 g L-1) were incorporated into the substrate Tropstrato Florestal®, consisting of 12 treatments in a 3 x 4 factorial scheme. A sample of the substrate in each treatment was sent for analysis of its physical and chemical attributes. To evaluate the effect of the treatments on the physical-chemical attributes of the substrate, was used the multivariate principal components analyses. The levels of fertilizer and hydrogel doses were correlated with the attributes of the substrates obtained in each treatment. The incorporation of different fertilizer levels and hydrogel doses to the substrate modified their chemical and physical attributes. Fertilizers have influenced mainly the chemical attributes of the substrate, whereas hydrogels have influenced the physical attributes, mainly those related to water retention capacity and availability.

A incorporação do hidrogel ao substrato utilizado no viveiro florestal promove melhorias em seus atributos físico-químicos. Porém vários fatores influenciam na eficiência do hidrogel, como o aumento de sais, promovido pela adubação do substrato. Portanto, este estudo teve como objetivo avaliar os efeitos da incorporação de níveis de adubação e doses de hidrogel sobre os atributos físico-químicos de um substrato para a produção de mudas florestais. Foram incorporados ao substrato Tropstrato Florestal® diferentes níveis da adubação de base comumente utilizada no viveiro (100%, 50% e 0%) e diferentes doses do hidrogel (0, 1, 2 e 3 g L-1), consistindo em 12 tratamentos em esquema fatorial 3 x 4. Uma amostra do substrato em cada tratamento foi encaminhada para análise de seus atributos físicos e químicos. Para avaliar o efeito dos tratamentos sobre os atributos físico-químicos do substrato foi utilizada a análise multivariada de componentes principais. Os níveis de adubação e doses de hidrogel foram correlacionados com os atributos dos substratos obtidos em cada tratamento. A incorporação de diferentes níveis de adubação e doses de hidrogel ao substrato modificaram seus atributos químicos e físicos. A adubação influenciou principalmente os atributos químicos do substrato, enquanto que o hidrogel os atributos físicos, principalmente os relacionados à capacidade de retenção e disponibilidade de água.

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Objetivou-se avaliar a associação do uso de hidrogel e utilização da adubação nitrogenada na cultura do tomateiro de mesa. Foi conduzido um experimento, no Instituto Federal Goiano -Campus Morrinhos. As plantas foram conduzidas verticalmente utilizando-se fitilhos como suporte e mantendo-se oito cachos por planta. O delineamento experimental adotado foi o de blocos com os tratamentos ao acaso, com quatro repetições. Os tratamentos foram dispostos em parcelas subdivididas duas aplicações (com e sem gel hidroretentor) e quatro adubações nitrogenadas (0; 180; 360 e 540 kg ha-1). As adubações de cobertura foram realizadas aos 25; 40; 55; 70; 85; 100 e 115 dias após o transplantio das mudas, respectivamente. Verificou-se que a fonte de variação hidrogel ocorreu efeito significativos, no diâmetro do caule final, matéria verde e textura do fruto. Para o fator doses de nitrogênio, os resultados apontam incrementos nas características clorofila na região basal, média e apical da planta, diâmetro do caule final, matéria seca e verde, número de frutos médios, peso por quilograma de frutos médios na área útil, taxa de crescimento absoluto par altura da planta e produtividade por hectare. A aplicação do gel hidroretentor não influenciou na produção do tomateiro de mesa cv. Santy.

The objective of this study was to evaluate the association between hydrogel use and nitrogen fertilization in tomato crop. An experiment was conducted at the Federal Institute Goiano - Campus Morrinhos. The plants were conducted vertically using strips for support and maintaining eight bunches per plant. The experimental design was a randomized complete block design with four replications. The treatments were arranged in split plots, two applications (with and without hydrochloridating gel) and four nitrogen fertilizers (0; 180; 360 and 540 kg ha-1). Topdressing was performed at 25; 40; 55; 70; 85; 100 and 115 days after seedling transplantation, respectively. It was found that the source of hydrogel variation had significant effect on the final stem diameter, green matter and fruit texture. For the nitrogen dose factor, the results indicate increases in the chlorophyll characteristics in the basal, medium and apical region of the plant, final stem diameter, dry matter and green matter, number of average fruits, weight per kilogram of average fruits in the useful area, rate. of absolute growth for plant height and productivity per hectare.

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Objetivou-se avaliar a associação do uso de hidrogel e utilização da adubação nitrogenada na cultura do tomateiro de mesa. Foi conduzido um experimento, no Instituto Federal Goiano -Campus Morrinhos. As plantas foram conduzidas verticalmente utilizando-se fitilhos como suporte e mantendo-se oito cachos por planta. O delineamento experimental adotado foi o de blocos com os tratamentos ao acaso, com quatro repetições. Os tratamentos foram dispostos em parcelas subdivididas duas aplicações (com e sem gel hidroretentor) e quatro adubações nitrogenadas (0; 180; 360 e 540 kg ha-1). As adubações de cobertura foram realizadas aos 25; 40; 55; 70; 85; 100 e 115 dias após o transplantio das mudas, respectivamente. Verificou-se que a fonte de variação hidrogel ocorreu efeito significativos, no diâmetro do caule final, matéria verde e textura do fruto. Para o fator doses de nitrogênio, os resultados apontam incrementos nas características clorofila na região basal, média e apical da planta, diâmetro do caule final, matéria seca e verde, número de frutos médios, peso por quilograma de frutos médios na área útil, taxa de crescimento absoluto par altura da planta e produtividade por hectare. A aplicação do gel hidroretentor não influenciou na produção do tomateiro de mesa cv. Santy.(AU)

The objective of this study was to evaluate the association between hydrogel use and nitrogen fertilization in tomato crop. An experiment was conducted at the Federal Institute Goiano - Campus Morrinhos. The plants were conducted vertically using strips for support and maintaining eight bunches per plant. The experimental design was a randomized complete block design with four replications. The treatments were arranged in split plots, two applications (with and without hydrochloridating gel) and four nitrogen fertilizers (0; 180; 360 and 540 kg ha-1). Topdressing was performed at 25; 40; 55; 70; 85; 100 and 115 days after seedling transplantation, respectively. It was found that the source of hydrogel variation had significant effect on the final stem diameter, green matter and fruit texture. For the nitrogen dose factor, the results indicate increases in the chlorophyll characteristics in the basal, medium and apical region of the plant, final stem diameter, dry matter and green matter, number of average fruits, weight per kilogram of average fruits in the useful area, rate. of absolute growth for plant height and productivity per hectare.(AU)

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ABSTRACT: The objective of this study was to compare the polymerization shrinkage of Eclipse photopolymerization resin for prosthesis based on urethane dimethacrylate (UDMA) with that of three heat-cured acrylic resins based on polymethyl methacrylate (PMMA) after the polymerization process and immersion in water. A total of 40 prostheses were fabricated on a standard metallic upper edentulous model: group 1, Eclipse; group 2, Triplex hot; group 3, Veracril; and group 4, Lucitone 199. Subsequently, the polymerization contraction was tested using a microscope in which measurements were made in micrometres at 3 points located in the middle parts of the right and left sides and the middle part of the palate at three time points once the prosthesis was completed, after 30 days of immersion in water for 8 hours a day at a temperature of 37 °C, and after cutting the prosthesis at the level of the second premolar. ANOVA revealed that the contraction of the polymerization no statistically significant differences between the groups, (P> 0.05). The type of resin and its interaction with the processing method behaves similarly for all test resins. The Veracril heat-cured resin obtained the lowest contraction value in the three measurements (mm) and the highest value was obtained with the Eclipse photopolymerization resin. The Eclipse resin exhibited no lower polymerization shrinkage compared to conventional acrylic resins based on polymethyl methacrylate (PMMA), however it was not significantly affected by immersion in water.

RESUMEN: El objetivo de este estudio fue comparar la contracción de polimerización de la resina de fotopolimerización Eclipse para prótesis basadas en dimetacrilato de uretano (UDMA) con la de tres resinas acrílicas curadas con calor a base de polimetacrilato de metilo (PMMA) después del proceso de polimerización e inmersión en agua. Se fabricaron un total de 40 prótesis en un modelo edéntulo superior metálico estándar: grupo 1, Eclipse; grupo 2, triplex caliente; grupo 3, veracril; y grupo 4, Lucitone 199. Posteriormente, la contracción de la polimerización se probó utilizando un microscopio en el que se realizaron mediciones en micrometros en 3 puntos ubicados en las partes medias de los lados derecho e izquierdo y la parte media del paladar en tres puntos de tiempo una vez la prótesis se completó, después de 30 días de inmersión en agua durante 8 horas al día a una temperatura de 37 °C, y después de cortar la prótesis a nivel del segundo premolar. ANOVA reveló que la contracción de la polimerización no presenta diferencias estadísticamente significativas entre los grupos, (P> 0,05). El tipo de resina y su interacción con el método de procesamiento se comportan de manera similar para todas las resinas de prueba. La resina curada con calor Veracril obtuvo el valor de contracción más bajo en las tres mediciones (mm) y el valor más alto se obtuvo con la resina de fotopolimerización Eclipse. La resina Eclipse no mostró una contracción de polimerización menor en comparación con las resinas acrílicas convencionales basadas en polimetilmetacrilato (PMMA), sin embargo, no se vio afectada significativamente por la inmersión en agua.

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