Browsing by Issue Date, starting with "2021-12-14"
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- Multifunctional Gelatin/Chitosan Electrospun Wound Dressing Dopped with Undaria pinnatifida Phlorotannin-Enriched Extract for Skin RegenerationPublication . Ferreira, Carolina A. M.; Januário, Adriana P.; Félix, Rafael; Alves, Nuno; Lemos, Marco F.L.; Dias, Juliana R.The similarities of electrospun fibers with the skin extracellular matrix (ECM) make them promising structures for advanced wound dressings. Moreover, infection and resistance in wounds are a major health concern that may be reduced with antibacterial wound dressings. In this work, a multifunctional wound dressing was developed based on gelatin/chitosan hybrid fibers dopped with phlorotannin-enrich extract from the seaweed Undaria pinnatifida. The intrinsic electrospun structure properties combined with the antimicrobial and anti-inflammatory properties of phlorotannin-enrich extract will enhance the wound healing process. Electrospun meshes were produced by incorporating 1 or 2 wt% of extract, and the structure without extract was used as a control. Physico-chemical, mechanical, and biological properties were evaluated for all conditions. Results demonstrated that all developed samples presented a homogenous fiber deposition with the average diameters closer to the native ECM fibrils, and high porosities (~90%) that will be crucial to control the wound moist environment. According to the tensile test assays, the incorporation of phlorotannin-enriched extract enhances the elastic performance of the samples. Additionally, the extract incorporation made the structure stable over time since its in vitro degradation rates decreased under enzymatic medium. Extract release profile demonstrated a longstanding delivery (up to 160 days), reaching a maximum value of ~98% over time. Moreover, the preliminary antimicrobial results confirm the mesh’s antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus. In terms of biological characterization, no condition presented cytotoxicity effects on hDNF cells, allowing their adhesion and proliferation over 14 days, except the condition of 2 wt% after 7 days. Overall, the electrospun structure comprising phlorotannins-enriched extract is a promising bioactive structure with potential to be used as a drug delivery system for skin regeneration by reducing the bacterial infection in the wound bed.
- Establishing a minimal clinically important difference in pulmonary rehabilitation: Digging in the methodsPublication . Paixão, Cátia; Rebelo, Patrícia; Oliveira, Ana; Jácome, Cristina; Cruz, Joana; Marques, Alda
- Are Young Swimmers Short and Middle Distances Energy Cost Sex-Specific?Publication . Massini, Danilo A.; Almeida, Tiago A. F.; Vasconcelos, Camila M. T.; Macedo, Anderson G.; Espada, Mário A. C.; Reis, Joana F.; Alves, Francisco J. B.; Fernandes, Ricardo J. P.; Filho, Dalton M. PessôaThis study assessed the energy cost in swimming (C) during short and middle distances to analyze the sex-specific responses of C during supramaximal velocity and whether body composition account to the expected differences. Twenty-six swimmers (13 men and 13 women: 16.7 ± 1.9 vs. 15.5 ± 2.8 years old and 70.8 ± 10.6 vs. 55.9 ± 7.0 kg of weight) performed maximal front crawl swimming trials in 50, 100, and 200 m. The oxygen uptake ((Formula presented.) O2) was analyzed along with the tests (and post-exercise) through a portable gas analyser connected to a respiratory snorkel. Blood samples were collected before and after exercise (at the 1st, 3rd, 5th, and 7th min) to determine blood lactate concentration [La–]. The lean mass of the trunk (LMTrunk), upper limb (LMUL), and lower limb (LMLL) was assessed using dual X-ray energy absorptiometry. Anaerobic energy demand was calculated from the phosphagen and glycolytic components, with the first corresponding to the fast component of the (Formula presented.) O2 bi-exponential recovery phase and the second from the 2.72 ml × kg–1 equivalent for each 1.0 mmol × L–1 [La–] variation above the baseline value. The aerobic demand was obtained from the integral value of the (Formula presented.) O2 vs. swimming time curve. The C was estimated by the rate between total energy releasing (in Joules) and swimming velocity. The sex effect on C for each swimming trial was verified by the two-way ANOVA (Bonferroni post hoc test) and the relationships between LMTrunk, LMUL, and LMLL to C were tested by Pearson coefficient. The C was higher for men than women in 50 (1.8 ± 0.3 vs. 1.3 ± 0.3 kJ × m–1), 100 (1.4 ± 0.1 vs. 1.0 ± 0.2 kJ × m–1), and 200 m (1.0 ± 0.2 vs. 0.8 ± 0.1 kJ × m–1) with p < 0.01 for all comparisons. In addition, C differed between distances for each sex (p < 0.01). The regional LMTrunk (26.5 ± 3.6 vs. 20.1 ± 2.6 kg), LMUL (6.8 ± 1.0 vs. 4.3 ± 0.8 kg), and LMLL (20.4 ± 2.6 vs. 13.6 ± 2.5 kg) for men vs. women were significantly correlated to C in 50 (R2adj = 0.73), 100 (R2adj = 0.61), and 200 m (R2adj = 0.60, p < 0.01). Therefore, the increase in C with distance is higher for men than women and is determined by the lean mass in trunk and upper and lower limbs independent of the differences in body composition between sexes.