CDRsp - Artigos em revistas internacionais
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- Electromyographic activity of shoulder muscles on two preventive exercise programmes for swimmer’s shoulder: elastic band versus weightPublication . Tavares, Nuno; Castro, Maria António; Vilas-Boas, João Paulo; Fong, DanielStrength programmes have shown good results in preventing swimmer’s shoulder. However, there aren’t studies based on electromyographic (EMG) analysis in these programmes. This study aims to compare an EMG activity of the middle trapezius (MT), lower trapezius (LT), infraspinatus (IS), serratus anterior (SA), and pectoralis major (PM) in two swimmer’s shoulder preventive programmes – one performed with elastic band and the other with weights. Twenty competitive swimmers performed two strength programmes consisting of five exercises each, while the analysis of EMG activity in MT, LT, IS, SA, and PM for each exercise was recorded. The superficial EMG was used to collect data at a sampling frequency of 1000 hz. The Paired Sample T-test or the Wilcoxon test was applied to compare EMG activity between programmes. The internal rotation at 90º (p < 0.001) and external rotation at 90º (p ≤ 0.01) exercises produced high myoelectric shoulder muscle activity with an elastic band. Conversely, scapular punches (p < 0.001) exercise has high shoulder EMG activity when performed with weights. Performing the same preventive exercise programme with two different instruments produces great variability in the myoelectric activity of the shoulder muscles.
- Characterisation of Portuguese RC Precast Industrial Building StockPublication . Rodrigues, H.; Sousa, R.; Vitorino, H.; Batalha, N.; Varum, H.; Fernandes, P.; Liu, ZaobaoThe construction of a vulnerability model requires reliable information on the features of the buildings in the study. The purpose of this work is the characterisation of the precast industrial buildings in Portuguese industrial park, based on the survey of 73 design projects of existing buildings. The collected data are based on a previous study on the features that influence the seismic response of this type of buildings. The parameters collected are associated with the global geometry and specific elements characteristics (e.g., column dimensions, reinforcement ratios, and connections details), to the mechanical properties of the materials and other parameters that can give some important information in the characterisation of the buildings (e.g., construction year and localization). In the end, a comparison with other available databases, namely, from Italy and Turkey, is done in order to conclude about the similarity. This information is important to define representative experimental specimens and numerical simulation to conduce seismic risk analysis.
- Statistical Modeling of Lower Limb Kinetics During Deep Squat and Forward LungePublication . Roeck, Joris De; Houcke, J. Van; Almeida, D.; Galibarov, P.; Roeck, L. De; Audenaert, Emmanuel A.Purpose: Modern statistics and higher computational power have opened novel possibilities to complex data analysis. While gait has been the utmost described motion in quantitative human motion analysis, descriptions of more challenging movements like the squat or lunge are currently lacking in the literature. The hip and knee joints are exposed to high forces and cause high morbidity and costs. Pre-surgical kinetic data acquisition on a patient-specific anatomy is also scarce in the literature. Studying the normal inter-patient kinetic variability may lead to other comparable studies to initiate more personalized therapies within the orthopedics. Methods: Trials are performed by 50 healthy young males who were not overweight and approximately of the same age and activity level. Spatial marker trajectories and ground reaction force registrations are imported into the Anybody Modeling System based on subject-specific geometry and the state-of-the-art TLEM 2.0 dataset. Hip and knee joint reaction forces were obtained by a simulation with an inverse dynamics approach. With these forces, a statistical model that accounts for inter-subject variability was created. For this, we applied a principal component analysis in order to enable variance decomposition. This way, noise can be rejected and we still contemplate all waveform data, instead of using deduced spatiotemporal parameters like peak flexion or stride length as done in many gait analyses. In addition, this current paper is, to the authors’ knowledge, the first to investigate the generalization of a kinetic model data toward the population. Results: Average knee reaction forces range up to 7.16 times body weight for the forwarded leg during lunge. Conversely, during squat, the load is evenly distributed. For both motions, a reliable and compact statistical model was created. In the lunge model, the first 12 modes accounts for 95.26% of inter-individual population variance. For the maximal-depth squat, this was 95.69% for the first 14 modes. Model accuracies will increase when including more principal components. Conclusion: Our model design was proved to be compact, accurate, and reliable. For models aimed at populations covering descriptive studies, the sample size must be at least 50.
- Additive manufactured porous biomaterials targeting orthopedic implants: A suitable combination of mechanical, physical and topological propertiesPublication . Bartolomeu, F.; Dourado, N.; Pereira, F.; Alves, N.; Miranda, G.; Silva, F. S.Orthopedic implants are under incessant advancement to improve their interactions with surrounding bone tissue aiming to ensure successful outcomes for patients. A successful biological interaction between implant and surrounding bone depends on the combination of mechanical, physical and topological properties. Hence, Ti6Al4V cellular structures appear as very promising solutions towards the improvement of conventional orthopedic implants. This work addresses a set of fundamental tools that allow improving the design of Ti6Al4V cellular structures produced by Selective Laser Melting (SLM). Three-point bending tests were carried out to estimate the elastic modulus of the produced structures. Morphological analysis allowed to evaluate the dimensional differences that were noticed between the model CAD and the SLM structures. Finite element models (adjusted CAD) were constructed with the experimentally obtained dimensions to replicate the mechanical response of the SLM structures. Linear correlations were systematically found for the dimensions of the SLM structures as a function of the designed model CAD dimensions. This has also been observed for the measured porosities as a function of the designed CAD models. This data can be used in further FE analyses as design guidelines to help engineers fabricating near-net-shape SLM Ti6Al4V cellular structures. Besides, polished and sandblasted surface treatments performed on the Ti6Al4V cellular structures allowed to obtain suitable properties regarding roughness and wettability when compared to as-produced surfaces. The capillarity tests showed that all the analyzed Ti6Al4V structures are able to transport fluid along its structure. The cell viability tests demonstrate Ti6Al4V cellular structures SLM produced did not release toxic substances to the medium, indicating that these structures can assure a suitable environment for cells to proliferate and attach. This study proposes a design methodology for Ti6Al4V cellular structures, that owe suitable mechanical properties but also provide a proper combination of porosity, roughness, wettability, capillarity and cell viability, all of them relevant for orthopedic applications. A Ti6Al4V cellular structured hip implant prototype gathering the suitable features addressed in this study was successfully SLM-produced.
- Preserving and hydrogel-matrixing the bioactive properties of aromatic medicinal halophytic herbs from the coastline of the Iberian PeninsulaPublication . Parracho, Tiago; Cruz, Pedro F.; Peralta, Claúdia C.; Silva, Cândida G.; Campos, Maria Jorge; Neves, Marta; Cordeiro, Rachel; Trindade, Daniela; Moura, Carla; Almeida, Zaida L.; Pereira, Cidália D.; Guimarães, Carla; Brito, Rui M. M.; Guerra, Mauro; Reboredo, Fernando; Veríssimo, Paula; Vaz, Daniela C.; Santos Ribeiro, VâniaEdible wild plants are part of the ethnobotanic heritage of a certain geographical area and are important sources of essential oils, antioxidants, minerals, and special flavours. Corema album (Portuguese crowberry), Crithmum maritimum (sea fennel), Eryngium maritimum (sea holly), Helichrysum italicum (curry plant) and Otanthus maritimus (cottonweed) wildly flourish along the sandy dunes of the coast of the Iberian Peninsula. These plants are locally known for their beneficial properties, with important value for food, cosmetics and/or medicinal applications. Hence, leaves of these endemic species were collected at four different locations and submitted to different preserving treatments (oven-drying, freezing, and freeze-drying). Acetonic extracts of the different plants submitted to the different post-harvesting treatments were analysed regarding their antioxidant capacities and phenolic contents. Plant extracts were also analysed by diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR). In general, freeze-drying was the best method of preserving plant minerals, antioxidants (~4 mgVCEAC/g fw) and polyphenols (~5 mgGAE/g fw). Minerals were quantified via energy-dispersive X-ray fluorescence spectrometry, and despite their location, all plants were rich in Ca, Cl, K, S and P. Hierarchical clustering and principal component analyses (PCA) pointed towards chemical/metabolic proximity between taxonomic families. Alginate hydrogels loaded with 0.1 % and 0.2 % (w/v) of extracts presented homogenous surface properties by scanning electron microscopy, good mechanical tensile strength (~30 MPa) and antibacterial activity against S. aureus. Edible alginate hydrogels enriched with plant extracts hold great nutraceutical potential to be used as natural preservatives for food coating and packaging or as sources of bioactive compounds for biomedical applications.
- Biomechanical and bioenergetical evaluation of swimmers using fully-tethered swimming: A qualitative reviewPublication . Amado, Nuno M.; Morouço, Pedro, G.; Marques, Mário C.; Fernandes, Ricardo J.; Marinho, Daniel A.It is presented a qualitative review of the specialized literature on fully-tethered swimming, with the scopes of summarizing and highlighting published knowledge, identifying its gaps and limitations, and motivate future research. The major research conclusions can be summarized as follows: (i) tethered swimming is a reliable test to evaluate force exerted in water by swimmers; (ii) higher maximum values of force are obtained in breaststroke and butterfly, while average values are higher in front crawl; (iii) tethered forces present moderate to strong relationships with swimming velocity, and associations between forces diminish as swimming distance increases; (iv) 30 s maximal tethered swimming may be used as an adaptation of Wingate test for swimming; (v) differences in stroke mechanics can occur in tethered swimming but there is no evidence to suggest that they affect swimming performance; (vi) Tethered swimming is a valid methodology to evaluate aerobic energy contribution in swimming and recent investigations concluded that it can also provide information on the anaerobic contribution. Based on and stimulated by current knowledge, further research should focus on the following topics: (i) the usefulness of tethered swimming as a valid tool to evaluate other swimming techniques; (ii) differences in force parameters induced by gender or competitive level; (iii) defining accurate variables for estimation of anaerobic power and/or capacity using tethered swimming; (iv) bilateral asymmetries in exerted forces, and corresponding influence of breathing; (v) relative contribution of arms and legs for whole-body propelling forces
- Nanocomposites from β-Pinene and α-Pinene Copolymer: Synthesis, Characterization, and Antioxidant EvaluationPublication . Derdar, Hodhaifa; Cherifi, Zakaria; Mitchell, Geoffrey; Mateus, Artur; Zerrouki, Meziane; Hammoudi, Naima; Bachari, Khaldoun; Chebout, Redouane; Touahra, Fouzia; Bouchama, Abdelghani; Harrane, Amine; Meghabar, RachidIn this study, we present a novel and straightforward approach for the synthesis of copolymers and nanocomposites based on α- and β-pinene, employing an eco-friendly and cost-effective nano-reinforcing filler. The copolymers (α-co-β-P) were produced through cationic copolymerization, using AlCl3 as a catalyst. The structural characterization of the resulting copolymer was validated through FT-IR, 1H-NMR spectroscopy, and differential scanning calorimetry (DSC). The molecular weight of the obtained polymer is determined by Gel Permeation Chromatography (GPC) analysis and is about 4500 g/mol. Nanocomposites (α-co-β-P/Clay 2, 5, 8, and 10% by weight of nano-clay) were synthesized by combining clay and α-co-β-P copolymer in solution using ultrasonic irradiation. This ultrasound-assisted method was employed to enhance and assess the structural, morphological, and thermal properties of the pure copolymer. The morphology of the resultant nanocomposites was characterized using infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Thermogravimetric analysis (TGA) revealed that the nanocomposites exhibit a higher degradation temperature compared to the pure copolymer. The analyses provided evidence of the chemical modification of nano-clay layers and their uniform dispersion in the α-co-β-P copolymer matrix. Exfoliated structures were achieved for lower clay concentration (2% by weight), while intercalated structures and immiscible regions were observed for higher clay concentrations (5, 8, and 10% by weight). The antioxidant activity of α-pinene, β-pinene, and the obtained nanocomposites were studied using DPPH (2,2-diphenyl-1-picrylhydrazyl) as a model free-radical. The results demonstrate a significant antioxidant potential of the nanocomposites, showcasing their ability to effectively neutralize free-radicals. Finally, a novel procedure was devised for the rapid synthesis of copolymers and nanocomposites using α- and β-pinene.
- Permeation studies of chlorpyrifos through skin and synthetic membranes to improve the in vitro dermal absorption assay of lipophilic compounds with ethanolic receptorsPublication . Marques da Silva, Dorinda; Franco, Margarida; Lagoa, Ricardo; Violante, CristianaThe in vitro percutaneous absorption assay is standardized, but the common use of 50 % ethanol in the receptor compartment for lipophilic compounds is questioned. In parallel, the demand for animal-free methodologies is driving the application of synthetic membranes without standardization guidelines. To address these issues, this study investigated the permeation of the lipophilic compound chlorpyrifos using different ethanol-containing receptor fluids with human and pig skin ex vivo, and silicone and STRAT-M® membranes. The results considered several factors, particularly chlorpyrifos solubility and the contact angles between skin models and receptor fluids. Original experimental approaches demonstrated that ethanol from the receptor rapidly crosses to the donor compartment increasing chlorpyrifos diffusivity. Compared to the described in vivo dermal absorption, human skin and STRAT-M® yielded the best predictive permeation parameters. However, high percentage of ethanol in the receptor fluid can lead to an overestimation of percutaneous absorption. Summing up, it is important to carefully determine the concentration of ethanol to be used in the receptor fluid of lipophilic compounds’ assays while further research with synthetic membranes is needed prior to their wider adoption.
- Electrospun PEDOT-Based Meshes for Skin RegenerationPublication . Alves, Alexandra I. F.; Alves, Nuno M.; Dias, JulianaThe application of conductive polymers in wound dressings presents great potential for accelerated wound healing since their high electrical conductivity and biocompatibility facilitate the delivery of external electrical stimuli to cells and tissues, promoting cell differentiation and proliferation. Electrospinning is a very straightforward method for the preparation of polymeric wound dressings capable of mimicking the extracellular matrix of skin, promoting hemostasis, absorbing wound exudate, allowing atmospheric oxygen permeation and maintaining an appropriately moist environment. In this work, in situ chemically polymerized poly(3,4-ethylenedioxythiophene) (PEDOT) was achieved through hyaluronic acid-doping. The synthesized PEDOT was used for the production of conductive and biodegradable chitosan (CS)/gelatin (GEL)/PEDOT electrospun meshes. Additionally, the randomly aligned meshes were crosslinked with a 1,4-butanediol diglycidyl ether and their physicochemical and mechanical properties were investigated. The results show that the incorporation of a conductive polymer led to an increase in conductivity of the solution, density and fiber diameter that influenced porosity, water uptake, and dissolvability and biodegradability of the meshes, while maintaining appropriate water vapor permeation values. Due to their intrinsic similarity to the extracellular matrix and cell-binding sequences, CS/GEL/PEDOT electrospun nanofibrous meshes show potential as conductive nanofibrous structures for electrostimulated wound dressings in skin tissue engineering applications.
- Effect of Preventive Exercise Programs for Swimmer’s Shoulder Injury on Rotator Cuff Torque and Balance in Competitive Swimmers: A Randomized Controlled TrialPublication . Tavares, Nuno; Vilas-Boas, João Paulo; Castro, Maria AntónioBackground: Over the season, competitive swimmers experience a progressive imbalance in rotator cuff strength, predisposing them to a significant risk factor for a swimmer’s shoulder injury. Objectives: Verify the effectiveness of two 12-week preventive programs on the shoulder rotators’ peak torque and conventional/functional ratios. Design: A care provider- and participant-blinded, parallel, randomized controlled trial with three groups. Participants: Competitive swimmers aged 16 to 35 years with no prior clinical issues related to their shoulders. Interventions: Twice a week, over 12 weeks, the two experimental groups performed five exercises where the only difference was executing the program with weights or elastic bands, and the control group performed a sham intervention. Main outcome measures: The concentric and eccentric peak torque of the internal and external rotators of the dominant shoulder were assessed before and after the intervention using an isokinetic dynamometer Biodex System 3, at 60°/s, 120°/s, and 180°/s. Results: Among the experimental groups, only one test indicated a reduction (p ≤ 0.05) in rotator peak torque, while the control group showed a decrease (p ≤ 0.05) in five tests. Swimmers who completed the prevention programs demonstrated less imbalance in conventional/functional ratios than controls. Conclusions: Implementing a 12-week preventive program minimizes the progressive shoulder rotational imbalance over the season in competitive swimmers. Clinical Trial Registration number: NCT06552585.