1,557 research outputs found

    Design of a Flapping Fins Mechanism for Roll Damping of Yachts at Anchor: Kinematic, Hydrodynamic and Structural Study

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    : The design of a flapping fins stabilization system for yachts at anchor (zero speed conditions) is presented in this study. The solution presented in this manuscript took inspiration from a solution proposed for the design of a biologically inspired flapping UAV. Although the application was different, we used the same principles and methodology to design and study the stabilization mechanism discussed hereafter. The proposed system uses flapping fins to damp the roll oscillations of the vessel, and when the stabilization system is retracted, the surface of each of the fins is flush with the hull, thus offering minimum resistance when the ship is in cruise conditions. The unsteady forces of the flapping fins were computed using computational fluid dynamics, and they were used as input to conduct the structural and durability study of the proposed mechanism. The vessel's response to roll perturbations was also studied, using a multi-body dynamics approach. From the results obtained, and the design specifications defined, it was found that the response of the stabilization system was acceptable, and that the mechanism could withstand the inertial and hydrodynamic loads

    Anchoring of Aminophosphonates on Titanium Oxide for Biomolecular Coupling

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    Aminophosphonates were chosen for a first step functionalization of TiO2 grown on titanium, as they possess a phosphonate group on one end, that can be exploited for coupling with the oxide surface, and an amino group on the other end to enable further functionalization of the surface. The deposition of aminophosphonates with different chain lengths (6 and 12 methylenes) was investigated. Oxygen plasma treatment proved useful in increasing the number of 12OH groups at the TiO2 surface, thus helping to anchor the aminophosphonates. By combining different surface-sensitive experimental techniques, we found the existence of a discontinuous monolayer where the molecules are covalently coupled to the TiO2 surface. For the molecules with longer chains, we find evidence of their covalent coupling to the surface through Ti\u2013O\u2013P bond formation, of the exposure of the amino groups at the outer surface, and of an increase in the order of the layer upon thermal annealing

    Effect of plaque accumulation and occlusal overload on peri-implant bone loss

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    This paper presents a case report where the influence of plaque accumulation and overload on a dental implant was observed. The patient presented crown loss on one implant affected by peri-implant bone resorption and gingival inflammation associated with poor oral hygiene. After 12 months a single crown was delivered, but as soon as the occlusal load was applied bone loss and implant failure occurred. In the present case report the dental implant remained stable as long as the implant was not loaded, although a 100% plaque index and bleeding on probing were present during the entire followup period. In contrast, as soon as an occlusal load was applied periimplant bone loss and implant failure occurred. These observations suggest that plaque accumulation alone is not a triggering factor for peri-implant bone loss and implant failure. On the contrary, occlusal load, when not properly controlled, might cause bone resorption

    Automated digital image quantification of histological staining for the analysis of the trilineage differentiation potential of mesenchymal stem cells

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    BACKGROUND Multipotent mesenchymal stem cells (MSCs) have the potential to repair and regenerate damaged tissues and are considered as attractive candidates for the development of cell-based regenerative therapies. Currently, there are more than 200 clinical trials involving the use of MSCs for a wide variety of indications. However, variations in their isolation, expansion, and particularly characterization have made the interpretation of study outcomes or the rigorous assessment of therapeutic efficacy difficult. An unbiased characterization of MSCs is of major importance and essential to guaranty that only the most suitable cells will be used. The development of standardized and reproducible assays to predict MSC potency is therefore mandatory. The currently used quantification methodologies for the determination of the trilineage potential of MSCs are usually based on absorbance measurements which are imprecise and prone to errors. We therefore aimed at developing a methodology first offering a standardized way to objectively quantify the trilineage potential of MSC preparations and second allowing to discriminate functional differences between clonally expanded cell populations. METHOD MSCs originating from several patients were differentiated into osteoblasts, adipocytes, and chondroblasts for 14, 17, and 21 days. Differentiated cells were then stained with the classical dyes: Alizarin Red S for osteoblasts, Oil Red O for adipocytes, and Alcian Blue 8GX for chondroblasts. Quantification of differentiation was then performed with our newly developed digital image analysis (DIA) tool followed by the classical absorbance measurement. The results from the two techniques were then compared. RESULT Quantification based on DIA allowed highly standardized and objective dye quantification with superior sensitivity compared to absorbance measurements. Furthermore, small differences between MSC lines in the differentiation potential were highlighted using DIA whereas no difference was detected using absorbance quantification. CONCLUSION Our approach represents a novel method that simplifies the laboratory procedures not only for the quantification of histological dyes and the degree of differentiation of MSCs, but also due to its color independence, it can be easily adapted for the quantification of a wide range of staining procedures in histology. The method is easily applicable since it is based on open source software and standard light microscopy

    Adsorption of the rhNGF Protein on Polypropylene with Different Grades of Copolymerization

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    The surface properties of drug containers should reduce the adsorption of the drug and avoid packaging surface/drug interactions, especially in the case of biologically-derived products. Here, we developed a multi-technique approach that combined Differential Scanning Calorimetry (DSC), Atomic Force Microscopy (AFM), Contact Angle (CA), Quartz Crystal Microbalance with Dissipation monitoring (QCM-D), and X-ray Photoemission Spectroscopy (XPS) to investigate the interactions of rhNGF on different pharma grade polymeric materials. Polypropylene (PP)/polyethylene (PE) copolymers and PP homopolymers, both as spin-coated films and injected molded samples, were evaluated for their degree of crystallinity and adsorption of protein. Our analyses showed that copolymers are characterized by a lower degree of crystallinity and lower roughness compared to PP homopolymers. In line with this, PP/PE copolymers also show higher contact angle values, indicating a lower surface wettability for the rhNGF solution on copolymers than PP homopolymers. Thus, we demonstrated that the chemical composition of the polymeric material and, in turn, its surface roughness determine the interaction with the protein and identified that copolymers may offer an advantage in terms of protein interaction/adsorption. The combined QCM-D and XPS data indicated that protein adsorption is a self-limiting process that passivates the surface after the deposition of roughly one molecular layer, preventing any further protein adsorption in the long term

    Two-stage hepatectomy after autologous CD133+ stem cells administration: a case report

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    Extreme liver resection can provide a safer option and a chance of cure to otherwise unresectable patients when liver regeneration is boosted by PVE and stem cell administratio

    Targeted next-generation sequencing helps to decipher the genetic and phenotypic heterogeneity of hypertrophic cardiomyopathy

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    Hypertrophic cardiomyopathy (HCM) is mainly associated with myosin, heavy chain 7 (MYH7) and myosin binding protein C, cardiac (MYBPC3) mutations. In order to better explain the clinical and genetic heterogeneity in HCM patients, in this study, we implemented a target-next generation sequencing (NGS) assay. An Ion AmpliSeq Custom Panel for the enrichment of 19 genes, of which 9 of these did not encode thick/intermediate and thin myofilament (TTm) proteins and, among them, 3 responsible of HCM phenocopy, was created. Ninety-two DNA samples were analyzed by the Ion Personal Genome Machine: 73 DNA samples (training set), previously genotyped in some of the genes by Sanger sequencing, were used to optimize the NGS strategy, whereas 19 DNA samples (discovery set) allowed the evaluation of NGS performance. In the training set, we identified 72 out of 73 expected mutations and 15 additional mutations: the molecular diagnosis was achieved in one patient with a previously wild-type status and the pre-excitation syndrome was explained in another. In the discovery set, we identified 20 mutations, 5 of which were in genes encoding non-TTm proteins, increasing the diagnostic yield by approximately 20%: a single mutation in genes encoding non-TTm proteins was identified in 2 out of 3 borderline HCM patients, whereas co-occuring mutations in genes encoding TTm and galactosidase alpha (GLA) altered proteins were characterized in a male with HCM and multiorgan dysfunction. Our combined targeted NGS-Sanger sequencing-based strategy allowed the molecular diagnosis of HCM with greater efficiency than using the conventional (Sanger) sequencing alone. Mutant alleles encoding non-TTm proteins may aid in the complete understanding of the genetic and phenotypic heterogeneity of HCM: co-occuring mutations of genes encoding TTm and non-TTm proteins could explain the wide variability of the HCM phenotype, whereas mutations in genes encoding only the non-TTm proteins are identifiable in patients with a milder HCM status

    Development and validation of an art-inspired multimodal interactive technology system for a multi-component intervention for older people: a pilot study

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    IntroductionThe World Health Organization (WHO) acknowledges the presence of a significant body of research on the positive effects of the arts on health, considering a variety of factors including physical well-being, quality of life, and social and community impact. The model that underlies cultural welfare puts the performing arts, visual arts, and cultural heritage at the service of people personal and societal well-being. The potential connections between movements of the body and artistic content have been extensively studied over time, considering movement as a non-verbal language with a universal character.MethodsThis pilot study presents the results of the validation of an innovative multimodal system, the DanzArTe-Emotional Wellbeing Technology, designed to support active and participative experience of older people providing physical and cognitive activation through a full-body physical interaction with a traditional visual work of art of religious subject. DanzArTe supports a replicable treatment protocol for multidimensional frailty, administered through a low cost and scalable technological platform capable of generating real-time visual and auditory feedback (interactive sonification) from the automated analysis of individual as well as joint movement expressive qualities. The study involved 45 participants, 23 of whom participated in the DanzArTe program and 22 who were included in the control group.ResultsThe two groups were similar in terms of age (p = 0.465) and gender (p = 0.683). The results showed that the DanzArTe program had a positive impact on participants' self-perceived psychological health and well-being (Mean Psychological General Well-Being Index—Short T1 = 19.6 ± 4.3 Vs. T2 = 20.8 ± 4.9; p = 0.029). The same trend was not observed in the control group (p = 0.389).DiscussionThe findings suggest that such programs may have a significant impact particularly on the mental and social well-being of older adults and could be a valuable tool for promoting healthy aging and improving quality of life

    p38 MAPK and JNK Antagonistically Control Senescence and Cytoplasmic p16INK4A Expression in Doxorubicin-Treated Endothelial Progenitor Cells

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    Patients treated with low-dose anthracyclines often show late onset cardiotoxicity. Recent studies suggest that this form of cardiotoxicity is the result of a progenitor cell disease. In this study we demonstrate that Cord Blood Endothelial Progenitor Cells (EPCs) exposed to low, sub-apoptotic doses of doxorubicin show a senescence phenotype characterized by increased SA-b-gal activity, decreased TRF2 and chromosomal abnormalities, enlarged cell shape, and disarrangement of F-actin stress fibers accompanied by impaired migratory ability. P16 INK4A localizes in the cytoplasm of doxorubicin-induced senescent EPCs and not in the nucleus as is the case in EPCs rendered senescent by different stimuli. This localization together with the presence of an arrest in G2, and not at the G1 phase boundary, which is what usually occurs in response to the cell cycle regulatory activity of p16INK4A, suggests that doxorubicin-induced p16 INK4A does not regulate the cell cycle, even though its increase is closely associated with senescence. The effects of doxorubicin are the result of the activation of MAPKs p38 and JNK which act antagonistically. JNK attenuates the senescence, p16 INK4A expression and cytoskeleton remodeling that are induced by activated p38. We also found that conditioned medium from doxorubicin-induced senescent cardiomyocytes does not attract untreated EPCs, unlike conditioned medium from apoptotic cardiomyocytes which has a strong chemoattractant capacity. In conclusion, this study provides a better understanding of the senescence of doxorubicin-treated EPCs, which may be helpful in preventing and treating late onset cardiotoxicity

    Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

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    Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.
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