The effect of polycaprolactone nanofibers on the dynamic and impact behavior of glass fibre reinforced polymer composites

In this article, the effect of polycaprolactone nanofibers on the dynamic behavior of glass fiber reinforced polymer composites is investigated. The vibratory behavior of composite beams in their pristine state (without any nano modification) and the same beams modified with polycaprolactone fibers is considered experimentally. The experimental results show that the incorporation of polycaprolactone nanofibers increases the damping; however, it does not significantly affect the natural frequencies. Additionally, the paper analyses the effect of polycaprolactone nanofibers on the impact behavior of glass fiber/epoxy composites. This has already been analyzed experimentally in a previous study. In this work, we developed a finite element model to simulate the impact behavior of such composite laminates. Our results confirm the conclusions done experimentally and prove that composites reinforced with polycaprolactone nanofibers are more resistant to damage and experience less damage when subjected to the same impact as the pristine composites. This study contributes to the knowledge about the dynamic behavior and the impact resistance of glass fiber reinforced polymer composites reinforced with polycaprolactone nanofibers. The findings of this study show that interleaving with polycaprolactone nanofibers can be used to control the vibrations and improve the impact damage resistance of structures made of composite mats as aircrafts or wind turbines

Clinical relevance of biological variation of B-Type Natriuretic Peptide

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Biomimetic Hierarchically Arranged Nanofibrous Structures Resembling the Architecture and the Passive Mechanical Properties of Skeletal Muscles: A Step Forward Toward Artificial Muscle

Skeletal muscles are considered to date the best existing actuator in nature thanks to their hierarchical multiscale fibrous structure capable to enhance their strength and contractile performances. In recent years, driven by the growing of the soft robotics and tissue-engineering research field, many biomimetic soft actuators and scaffolds were designed by taking inspiration from the biological skeletal muscle. In this work we used the electrospinning technique to develop a hierarchically arranged nanofibrous structure resembling the morphology and passive biomechanical properties of skeletal muscles. To mimic the passive properties of muscle, a low-modulus polyurethane was used. Several electrospun structures (mats, bundles, and a muscle-like assembly) were produced with different internal 3D arrangements of the nanofibers. A thermal characterization through thermogravimetric and differential scanning calorimetry analysis investigated the physico-chemical properties of the material. The multiscale morphological similarities with the biological counterpart were verified by means of scanning electron microscopy investigation. The tensile tests on the different electrospun samples revealed that the muscle-like assembly presented slightly higher strength and stiffness compared to the skeletal muscle ones. Moreover, mathematical models of the mechanical behavior of the nanofibrous structures were successfully developed, allowing to better investigate the relationships between structure and mechanics of the samples. The promising results suggest the suitability of this hierarchical electrospun nanofibrous structure for applications in regenerative medicine and, if combined with active materials, in soft actuators for robotic

Comparison between BNP values measured in capillary blood samples with a POCT method and those measured in plasma venous samples with an automated platform

Letter to the Editor. Our data suggest that it is possible to measure BNP in fresh finger-stick samples of capillary whole blood with an acceptable reproducibility, and within 10 – 20 min to obtain results close correlated to those measured by the automated platform in plasma blood samples collected from a vein. The measurement of BNP in fresh finger-stick samples of capillary whole blood with this POCT method is in particular indicated for the management of HF patients at home and for the BNP assay in neonates and children

The relation between the minor chlorophyll spectral forms and fluorescence quenching in aggregated light harvesting chlorophyll a b complex II

The hypothesis that fluorescence quenching in aggregated light harvesting chlorophyll a/b protein complex II is associated with the formation of minor spectral forms absorbing near 655 nm and between 680 nm-690 nm is examined. Using an homogeneous LHCII preparation, steady-state absorption changes measured at room temperature are quantitatively compared with the associated steady state fluorescence changes by means of the Stepanov relation. It is demonstrated that upon LHCII aggregation, the relative fluorescence yield is constant for chlorophyll forms absorbing between 650 nm and 690 nm. This indicates that the minor chlorophyll forms formed upon LHCII aggregation are not quenching species