Effect of hamstring injuries on kicking in soccer using inverse dynamics

The hamstring strain is one of the most common injuries in soccer. The aim of the study was to describe a new procedure to evaluate the effect of hamstring injuries in kicking in soccer using the principles of inverse dynamics and to compare the results with an isokinetic test. The study focused on evaluating the difference between subjects having a history of hamstring injuries in the last 5 years and those that did not. Seventeen male professional soccer players performed five instep and side- foot kicks which were analysed using a force platform and a Vicon motion-capture system operating at 500Hz. The participants also took part in an isokinetic torque measurement at 60 °/s and 120 °/s. Kinematic variables, ground reaction forces and kinetic variables were compared across the two groups. Significant differences were observed between the previously injured and uninjured group in the time taken for the follow through in the instep kick, and the maximum hip flexion moment in the instep and side-foot kicks. No significant differences were found between the two groups in the traditional isokinetic test. These results indicate that the procedure employed could probably be very useful in the assessment of the effect of hamstring injuries in soccer.Las lesiones musculares del muslo tienen una gran incidencia en el fútbol. El objetivo del estudio ha sido desarrollar un nuevo procedimiento para evaluar el efecto de las lesiones de isquiotibiales en los golpeos con el pie s en el fútbol utilizando los principios de la dinámica inversa. El trabajo se ha centrado en la evaluación de la diferencia entre sujetos que habían sufrido la lesión en los últimos 5 años y los que no. Se analizaron 17 jugadores de fútbol profesionales realizando cinco tiros con el empeine y cinco con el interior del pie. Los movimientos se registraron mediante una plataforma de fuerza y un sistema de captura de movimiento Vicon funcionando a 500Hz. Los participantes también tomaron parte en una prueba de isocinético en la que se midió el torque isocinético en 60 º/s y 120 º/s. Se observaron diferencias significativas en los parámetros cinemáticos y cinéticos entre los dos grupos (lesionados y no lesionados) en la fase posterior del golpeo y en el instante de máxima flexión de cadera. No se encontraron diferencias significativas entre los dos grupos en la prueba isocinética tradicional. Estos resultados indican que el procedimiento empleado probablemente podría ser muy útil en la evaluación del efecto de las lesiones de isquiotibiales en el fútbol.Peer ReviewedAward-winnin

Recycling of Heterogeneous Mixed Waste Polymers through Reactive Mixing

Anything that is not recycled and/or recovered from waste represents a loss of raw materials. Recycling plastics can help to reduce this loss and to reduce greenhouse gases, improving the goal of the decarbonization of plastic. While the recycling of single polymers is well assessed, the recycling of mixed plastics is very difficult because of the strong incompatibility among the different polymers usually present in urban waste. In this work, heterogeneous mixed polymers, i.e., polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyethylenetherephthalate (PET) were processed using a laboratory mixer under different conditions of temperature, rotational speed and time to evaluate the effect of the above parameters on morphology, viscosity and mechanical properties of the final blends. Morphological analysis shows a strong incompatibility between the polyethylene matrix and the other dispersed polymers. The blends show, of course, a brittle behavior, but this behavior slightly improves with decreasing temperature and increasing rotational speed. A brittle-ductile transition was observed only at a high level of mechanical stress obtained by increasing rotational speed and decreasing temperature and processing time. This behavior has been attributed to both a decrease in the dimensions of the particles of the dispersed phase and to the formation of a small amount of copolymers that act as adhesion promoters between matrix and dispersed phases

Green Composites Based on Hedysarum coronarium with Outstanding FDM Printability and Mechanical Performance

The addition of natural scraps to biodegradable polymers has gained particular interest in recent years, allowing reducing environmental pollution related to traditional plastic. In this work, new composites were fabricated by adding 10% or 20% of Hedysarum coronarium (HC) flour to Poly (lactic acid) (PLA). The two formulations were first produced by twin screw extrusion and the obtained filaments were then employed for the fabrication of composites, either for compression molding (CM) or by fused deposition modeling (FDM), and characterized from a morphological and mechanical point of view. Through FDM it was possible to achieve dense structures with good wettability of the filler that, on the contrary, cannot be obtained by CM. The results indicate that the filler effectively acts as reinforcement, especially for FDM composites. The most remarkable enhancement was found in the flexural properties (+100% of modulus and ultimate strength), followed by tensile resistance and stiffness (+60%) and impact strength (+50%), whereas a moderate loss in tensile deformability was observed, especially at the highest loading. By adding HC to the polymeric matrix, it was possible to obtain a green, high-performance, and cost-effective composite, which could find applications for the fabrication of panels for furniture or the automotive industry

Establishment of an in vitro culture system, based on small intestinal crypt organoids, for the investigation of putative small intestinal stem cells

Small intestinal (SI) stem cells differentiate into short-lived progeny, except lysozyme-expressing Paneth cells. In vivo, the Tet-Op histone 2 B (H2B) - green fluorescent protein (GFP) fusion protein transgenic mouse has been employed to analyse the slow-cycling putative small intestinal epithelial stem cells, at cell position +4 (cp4 cells), through doxycycline-inducible transient expression of H2B-GFP. The aim of the study was to employ the same genetic mouse model in order to develop a culture system in which was possible to detect and investigate H2B-GFP-retaining putative SI stem cells. SI crypts isolated from 6-12 weeks old Tet-Op-H2B-GFP transgenic mice were established in culture (designated organoids) using growth factors and Matrigel. For in vitro transgene expression, doxycycline was added to the complete culture medium for 24/48 hours (pulse). H2B-GFP and lysozyme expression was studied by confocal and fluorescence microscopy. Percentages of H2B-GFP-retaining putative SI stem cells and of H2B-GFP-retaining Paneth cells persisting in organoids were determined by scoring GFP-immunoreactive cells. Ulex europaeus-I lectin (UEA-I) cell labelling, combined with flow cytometry, was employed in a pilot study aimed at establishing a protocol for the separation of H2B-GFP-retaining putative SI stem cells from H2B-GFP-retaining Paneth cells persisting in the small intestine of chased mice. After both 24 hours and 48 hours exposure (pulse) to the optimal concentration of doxycycline, the nuclei of all cells in SI organoids expressed H2B-GFP. During subsequent culture, in absence of doxycycline (chase period), there was gradual loss (due to cell division) of H2B-GFP. After 6 day chase, small numbers of H2B-GFP-retaining putative slow-cycling stem cells and Paneth cells were seen. Flow cytometric analyses indicated that to label SI crypt cells with UEA-I lectin is a promising approach for isolating putative SI stem cells for functional characterization. A method to induce ubiquitous transient expression of H2B-GFP in cultured SI organoids, compatible with regular organoid development, has been optimized. It allows detection, after a short chase period, of the slow-cycling H2B-GFP-retaining putative SI epithelial stem cells. The developed in vitro culture system will enable further characterisation of these cells and Paneth cells

Green composites based on pla and agricultural or marine waste prepared by fdm

Three dimensional-printability of green composites is recently growing in importance and interest, especially in the view of feasibility to valorize agricultural and marine waste to attain green fillers capable of reducing bioplastic costs, without compromising their processability and performance from an environmental and mechanical standpoint. In this work, two lignocellulosic fillers, obtained from Opuntia ficus indica and Posidonia oceanica, were added to PLA and processed by FDM. Among the 3D printed biocomposites investigated, slight differences could be found in terms of PLA molecular weight and filler aspect ratio. It was shown that it is possible to replace up to 20% of bioplastic with low cost and ecofriendly natural fillers, without significantly modifying the processability and the mechanical performance of the neat matrix; at the same time, an increase of surface hydrophilicity was found, with possible positive influence on the biodegradability of such materials after disposal

The effects of nanoclay on the mechanical properties, carvacrol release and degradation of a pla/pbat blend

The formulation of polymeric films endowed with the abilities of controlled release of antimicrobials and biodegradability is the latest trend of food packaging. Biodegradable polymer (Bio-Flex)-based nanocomposites containing carvacrol as an antimicrobial agent, and a nanoclay as a filler, were processed into blown films. The presence of such hybrid loading, while not affecting the overall filmability of the neat matrix, led to enhanced mechanical properties, with relative increments up to +70% and +200% in terms of elastic modulus and elongation at break. FTIR/ATR analysis and release tests pointed out that the presence of nanoclay allowed higher carvacrol loading efficiency, reasonably hindering its volatilization during processing. Furthermore, it also mitigated the burst delivery, thereby enabling a more controlled release of the antimicrobial agent. The results of mass loss tests indicated that all the formulations showed a rather fast degradation with mass losses ranging from 37.5% to 57.5% after 876 h. The presence of clay and carvacrol accelerated the mass loss rate of Bio-Flex, especially when added simultaneously, thus indicating an increased biodegradability. Such ternary systems could be, therefore, particularly suitable as green materials for food packaging applications, and for antimicrobial wrapping applications

The Turin Shroud face: the evidence of maxillo-facial trauma

The Turin Shroud (TS) is a linen cloth commonly associated with Jesus Christ, his crucifixion and burial. Several medical specialists have debated the injuries of the TS Man, nevertheless there are no detailed and quantitative data about the anatomy of the TS face. The purpose of this study was to analyse the cephalometric measurements of the face image of the TS. The TS face image was acquired by a picture and processed using a cephalometric software, Oris Ceph® (Up to date 2012). The image of the soft tissues was processed in order to obtain skeletal points and a cephalometric analysis of the soft and skeletal tissues was performed. Image processing of the TS face shows that the Man represented in it has undergone a maxillo-facial trauma, especially a left displacement of the mandible, probably due to temporo-mandibular joint lesions. This condition has not been described before, despite several studies on the subject

The Turin Shroud face: the evidence of maxillo-facial trauma

The Turin Shroud (TS) is a linen cloth commonly associated with Jesus Christ, his crucifixion and burial. Several medical specialists have debated the injuries of the TS Man, nevertheless there are no detailed and quantitative data about the anatomy of the TS face. The purpose of this study was to analyse the cephalometric measurements of the face image of the TS. The TS face image was acquired by a picture and processed using a cephalometric software, Oris Ceph® (Up to date 2012). The image of the soft tissues was processed in order to obtain skeletal points and a cephalometric analysis of the soft and skeletal tissues was performed. Image processing of the TS face shows that the Man represented in it has undergone a maxillo-facial trauma, especially a left displacement of the mandible, probably due to temporo-mandibular joint lesions. This condition has not been described before, despite several studies on the subject