Hedysarum coronarium-Based Green Composites Prepared by Compression Molding and Fused Deposition Modeling

In this work, an innovative green composite was produced by adding Hedysarum coronarium (HC) flour to a starch-based biodegradable polymer (Mater-Bi\uae, MB). The flour was obtained by grinding together stems, leaves and flowers and subsequently sieving it, selecting a fraction from 75 \ub5m to 300 \ub5m. Four formulations have been produced by compression molding (CM) and fused deposition modeling (FDM) by adding 5%, 10%, 15% and 20% of HC to MB. The influence of filler content on the processability was tested, and rheological, morphological and mechanical properties of composites were also assessed. Through CM, it was possible to obtain easily homogeneous samples with all filler amounts. Concerning FDM, 5% and 10% HC-filled composites proved also easily printable. Mechanical results showed filler effectively acted as reinforcement: Young\u2019s modulus and tensile strengths of the composites increased from 74.3 MPa to 236 MPa and from 18.6 MPa to 33.4 MPa, respectively, when 20% of HC was added to the pure matrix. FDM samples, moreover, showed higher mechanical properties if compared with CM ones due to rectilinear infill and fibers orientation. In fact, regarding the 10% HC composites, Young\u2019s modulus of the CM and FDM ones displayed a relative increment of 176% and 224%, respectively

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

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

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

Processing-structure-property relationships of electrospun PLA-PEO membranes reinforced with enzymatic cellulose nanofibers

Three different solvent mixtures were used to prepare electrospun membranes based on polylactic acid (PLA), polyethylene oxide (PEO) and enzymatic cellulose nanofibers (CNF). The materials were characterized from a morphological, spectroscopic, mechanical and rheological point of view. Furthermore, swelling test were performed in order to assess the water uptake of each sample. The results put into evidence that the choice of the solvents affects the structure and the properties of the membranes. Among the protocols tested, using chloroform/acetone/ethanol mixture was found to allow a high degree of CNF dispersion and a good electrospinnability of polymer solutions. These features led to membranes with impressive improvement of mechanical properties (+350% in stiffness, +350% in tensile strength and +500% in toughness) with respect to those of PLA/PEO and dramatically increased the water uptake of these materials (up to +350% within 120 min)

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

Rapid One-Step Fabrication of Graphene Oxide-Decorated Polycaprolactone Three-Dimensional Templates for Water Treatment

Coating of flexible substrates is crucial to prepare versatile, multifunctional materials. However, exploration of effective fabrication approaches is still a challenging issue, because the pathways generally proposed require time-consuming, multistep protocols. Here, we developed a one-pot process for decorating either pearl necklace-like or fibrous fluffy-like structures of polycaprolactone (PCL) with graphene oxide (GO) skin. PCL solutions were dry jet-wet electrosprayed or electrospun into a stirred liquid collector constituted by ethanol-containing GO nanoparticles. The stirred liquid collector enables the formation of 3D-structures, whose microarchitecture can be designed by controlling the rheological behavior of PCL solutions. Two molecular weights of PCL were used (45 or 80 kDa) with ensuing different viscosity, which determines the prevalent formation of beads or fibers. The presence of GO in the coagulation bath allows the polymeric structures to be rapidly wrapped by those nanoparticles. Graphenic coating endows these materials with the intriguing peculiarities of GO: PCL/GO nanocomposites displayed increments of elastic modulus ranging from 1250% (beads) to 3300% (fibers) with respect to the neat matrices and a change from hydrophobic to amphiphilic character. A potential application of such devices in water treatment was assessed in phenol removal. The results pointed out that PCL/GO scaffolds retain the same sorption capacity of GO nanoparticles, while bringing several advantages in terms of handling, robustness, and recyclability. The ease of control of the process, as well as its fastness and cost-effectiveness could open a wide range of scenarios, including sensors, energy, catalysis, biomedicine

In vitro and in vivo inhibition of breast cancer cell growth by targeting the Hedgehog/GLI pathway with SMO (GDC-0449) or GLI (GANT-61) inhibitors.

Aberrant Hedgehog (Hh)/glioma-associated oncogene (GLI) signaling has been implicated in cancer progression. Here, we analyzed GLI1, Sonic Hedgehog (Shh) and NF-κB expression in 51 breast cancer (ductal carcinoma) tissues using immunohistochemistry. We found a positive correlation between nuclear GLI1 expression and tumor grade in ductal carcinoma cases. Cytoplasmic Shh staining significantly correlated with a lower tumor grade. Next, the in vitro effects of two Hh signaling pathway inhibitors on breast cancer cell lines were evaluated using the Smoothened (SMO) antagonist GDC-0449 and the direct GLI1 inhibitor GANT-61. GDC-0449 and GANT-61 exhibited the following effects: a) inhibited breast cancer cell survival; b) induced apoptosis; c) inhibited Hh pathway activity by decreasing the mRNA expression levels of GLI1 and Ptch and inhibiting the nuclear translocation of GLI1; d) increased/decreased EGFR and ErbB2 protein expression, reduced p21- Ras and ERK1/ERK2 MAPK activities and inhibited AKT activation; and e) decreased the nuclear translocation of NF-κB. However, GANT-61 exerted these effects more effectively than GDC-0449. The in vivo antitumor activities of GDC-0449 and GANT- 61 were analyzed in BALB/c mice that were subcutaneously inoculated with mouse breast cancer (TUBO) cells. GDC-0449 and GANT-61 suppressed tumor growth of TUBO cells in BALB/c mice to different extents. These findings suggest that targeting the Hh pathway using antagonists that act downstream of SMO is a more efficient strategy than using antagonists that act upstream of SMO for interrupting Hh signaling in breast cancer