Avaliação da Actividade Muscular com e sem utilização de calçado instável e aplicação de um desequilíbrio

Objectivo: Este estudo visa avaliar a influência de sapatilhas MBT na actividade electromiográfica do tibial anterior, gastrocnémio, recto femoral e bicípite femoral, aplicando um desequilíbrio. Metodologia: A amostra foi constituída por 30 indivíduos do sexo feminino, com idades entre os 21 e os 57 anos. Os dados foram recolhidos através de electromiografia, tendo sido utilizada a plataforma de forças e dinamómetro para monitorizar o desequilíbrio. Resultados: Não foram encontradas diferenças estatisticamente significativas no tempo de início de activação muscular com calçado MBT e descalço. Conclusão: O uso de MBT, comparando com descalço, não influenciou os tempos de início de activação muscular.Objective: The main purpose of this project were to study the infl uence of MBT in electromyographi c activity of, Tibialis Anterior, Gastrocnemius, Rectus femoris and Biceps femoris during an external pertubation . Metodology : 30 subjects (female) with ages between 21 and 57 years old participate in this study. EMG activities were recorded during an exte rnal perturbation by surface electromyography, and monitorized using a platform and a dynamometer to measure the force . Results: Results showed no statistically significative differences in the initial time muscular activation, comparing the use of MBT and with bare feet Conclusion: The use of MBT doesn’t influenciate the initial time of muscular activation

Short-latency responses in chronic ankle instability

Ankle proprioceptive impairments after ankle sprain appear to be in the origin of the neuromuscular dysfunction in Chronic Ankle Instability (CAI), however the analysis of this condition has been focused on a unilateral approach. Considering that proprioceptive information have a determinant role in ipsilesional limb responses but also the contralesional ones, the present study aims to analyze the bilateral Short Latency Responses (SLR) in response to an unilateral perturbation in individuals with CAI. Two groups of athletes participated in the present study. One was composed by participants presenting CAI (CAI group, n = 16), while the other was composed by participants not presenting ankle sprain episodes (control group, n = 20). The electromyographic activity of the Peroneal Brevis and Longus (PB and PL), Tibialis Anterior (TA) and Soleus (SOL) muscles was collected during a unilateral sudden inversion perturbation in both the support and perturbed limbs. The timing of muscle activation of both limbs was used for analysis. Delayed SLR of TA (p = 0.009) and in SOL (p = 0.042) muscles were observed in the contralesional limb of the CAI group in the support position compared to the control group. In CAI group, delayed SLR of PB (p = 0.023) and SOL (p = 0.004) muscles was found in the contralesional limb in the support position compared to the ipsilesional one. The rehabilitation of individuals with CAI should also be focused on the contralesional limb while assuming a support position and also, contralesional limb should not be considered a reference for comparison between limbs.info:eu-repo/semantics/publishedVersio

La posición taxonómica de Scilla beirana Samp. (Hyacinthaceae)

Populations of Scilla beirana Samp. were sampled in NW Portugal and compared with its relatives S. ramburei Boiss, and S. peruviana L. Leaf and scape anatomy, morphology, chromosome number and idiogram were identical in S. beirana and S. ramburei, but differed from S. peruviana. Diagnostic characters previously used to discriminate S. beirana (width of leaves and flower number) showed continuous, but not clinal, variation, and failed to provide a clear-cut basis for identification and no other morphological attributes were found to separate the taxa. All available evidence suggests that S. beirana should be put into synonymy with S. ramburei, as was earlier suggested by COUTINHO (1935).Se muestreó Scilla beirana Samp. en diversas poblaciones del noroeste de Portugal y se comparó con dos táxones con los que se había relacionado previamente, S. ramburei Boiss, y S. peruviana L. La macromorfología, la anatomía de la hoja y escapo, el número cromosomático y el idiograma de S. beirana y S. ramburei fueron indistinguibles, pero diferentes de los de S. peruviana. Los caracteres diagnósticos que se habían utilizado previamente para discriminar a S. beirana -anchura foliar y número de flores- revelaron una variación continua y no permitieron diferenciarla de S. ramburei, en la cual debería ser incluida como sinónimo, tal como había sugerido COUTINHO (1935)

SERS from pyridine adsorbed on electrodispersed platinum electrodes

SERS of pyridine adsorbed on electrodispersed platinum electrodes is reported. Electrodispersed platinum surfaces are obtained by electroreducing hydrous platinum oxide layers. The intensity of the Raman scattering for adsorbed pyridine is enhanced by at least one order of magnitude, after normalizing with respect to the area increase. The estimated Raman enhancement factor is lower than that reported for roughened silver electrodes but it is still sufficiently large to allow Raman scattering from adsorbates on platinum to be detectable. Surface changes (ageing) of the metal surface can be also followed by SERS.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Synthesis, Characterization and use of Nb2 O5 based Catalysts in Producing Biofuels by Transesterification, Esterification and Pyrolysis

Nb2O5/HX (X = HSO4-, H2PO4-, NO3-) compounds were obtained from the treatment of niobium acid (Nb2O5·xH2O) with sulfuric, phosphoric, and nitric acids as well as Nb2O5 and Nb2O5·xH2O have been investigated as catalysts for the transesterification, esterification and pyrolysis of vegetable oils. The compounds were characterized by thermal analysis (DTA-TGA), spectroscopy (DRX, FT-IR and FT-Raman), surface area (BET) and the acidity (Ho) determined by n-butylamine titration using the Hammet´s indicator method. It was observed that after the acid treatment both the surface area and the acidity decreased as compared to the starting Nb2O5·xH2O. The only exception was a higher acidity verified when nitric acid was used. Among the catalyst investigated, the Nb2O5/H3PO4 presented the highest activity in the alcoholysis of soybean oil with different mono-alcohols (methanol, ethanol, 2-propanol, n-butanol). All tested solids seemed to stabilize the carboxylic acids formed during the pyrolysis, yielding higher acid numbers for the obtained products. Finally, the use of Nb2O5/H3PO4 and Nb2O5/H2SO4 as catalysts for the esterification showed better activity than Nb2O5·xH2O and Nb2O5

Modulatory effects of cAMP and PKC activation on gap junctional intercellular communication among thymic epithelial cells

<p>Abstract</p> <p>Background</p> <p>We investigated the effects of the signaling molecules, cyclic AMP (cAMP) and protein-kinase C (PKC), on gap junctional intercellular communication (GJIC) between thymic epithelial cells (TEC).</p> <p>Results</p> <p>Treatment with 8-Br-cAMP, a cAMP analog; or forskolin, which stimulates cAMP production, resulted in an increase in dye transfer between adjacent TEC, inducing a three-fold enhancement in the mean fluorescence of coupled cells, ascertained by flow cytometry after calcein transfer. These treatments also increased Cx43 mRNA expression, and stimulated Cx43 protein accumulation in regions of intercellular contacts. VIP, adenosine, and epinephrine which may also signal through cyclic nucleotides were tested. The first two molecules did not mimic the effects of 8-Br-cAMP, however epinephrine was able to increase GJIC suggesting that this molecule functions as an endogenous inter-TEC GJIC modulators. Stimulation of PKC by phorbol-myristate-acetate inhibited inter-TEC GJIC. Importantly, both the enhancing and the decreasing effects, respectively induced by cAMP and PKC, were observed in both mouse and human TEC preparations. Lastly, experiments using mouse thymocyte/TEC heterocellular co-cultures suggested that the presence of thymocytes does not affect the degree of inter-TEC GJIC.</p> <p>Conclusions</p> <p>Overall, our data indicate that cAMP and PKC intracellular pathways are involved in the homeostatic control of the gap junction-mediated communication in the thymic epithelium, exerting respectively a positive and negative role upon cell coupling. This control is phylogenetically conserved in the thymus, since it was seen in both mouse and human TEC preparations. Lastly, our work provides new clues for a better understanding of how the thymic epithelial network can work as a physiological syncytium.</p

Analysis of ground reaction force and electromyographic activity of the gastrocnemius muscle during double support

O documento em anexo encontra-se na versão post-print (versão corrigida pelo editor).Purpose: Mechanisms associated with energy expenditure during gait have been extensively researched and studied. According to the double-inverted pendulum model energy expenditure is higher during double support, as lower limbs need to work to redirect the centre of mass velocity. This study looks into how the ground reaction force (GRF) of one limb affects the muscle activity required by the medial gastrocnemius (MG) of the contralateral limb during step-to-step transition. Methods: Thirty-five subjects were monitored as to the MG electromyographic activity (EMGa) of one limb and the GRF of the contralateral limb during double support. Results: After determination of the Pearson correlation coefficient (r), a moderate correlation was observed between the MG EMGa of the dominant leg and the vertical (Fz) and anteroposterior (Fy) components of GRF of the non-dominant leg (r=0.797, p<0.0001; r=-0.807, p<0.0001) and a weak and moderate correlation was observed between the MG EMGa of the non-dominant leg and the Fz and Fy of the dominant leg, respectively (r=0.442, p=0.018; r=-0.684 p<0.0001). Conclusions: The results obtained suggest that during double support, GRF is associated with the EMGa of the contralateral MG and that there is an increased dependence between the GRF of the non-dominant leg and the EMGa of the dominant MG

Modelo farmacocinético de florfenicol en tilapias (Oreochromis niloticus) sometidas a diferentes temperaturas de crianza.

El objetivo de este trabajo fue desarrollar un modelo farmacocinético de florfenicol en plasma de tilapia (Oreochromis niloticus) sometido a diferentes temperaturas de crianza para estimar la concentración plasmática de los protocolos indicados en los prospectos de productos de florfenicol autorizados en Brasil. Para ello, se creó un modelo farmacocinético a partir de datos previamente publicados sobre la concentración plasmática de florfenicol en tilapia del Nilo sometida a diferentes temperaturas. La construcción del modelo farmacocinético se realizó con el programa Monolix 2020R1 de Lixoft®, partiendo de los datos de farmacocinética plasmática de florfenicol encontrados en la literatura. Las concentraciones plasmáticas de florfenicol se estimaron a partir de tratamientos con dosis de 10, 15 y 20 mg/kg administradas cada 24 horas durante 10 días, a temperaturas de 18, 21, 26 y 30°C, utilizando el programa Simulx 2020 de Lixoft®. Los parámetros de tiempo de latencia de absorción (Tlag) y aclaramiento (Cl) mostraron una correlación positiva con la temperatura, mientras que la constante de absorción (Ka) mostró una correlación negativa. Asimismo, se puede observar que los animales mantenidos a 30 ºC tienen una mediana de la concentración plasmática móvil de aproximadamente la mitad que los animales criados a 18 ºC y tratados con las mismas dosis. Por otra parte, las dosis crecientes determinaron un aumento de aproximadamente el doble de las medianas de la concentración plasmática. El modelo propuesto permitió cuantificar el impacto de la temperatura en los parámetros farmacocinéticos, además de estimar las concentraciones plasmáticas de florfenicol para tilapia a diferentes temperaturas de crianza