143 research outputs found

    Speed and power predictors of change of direction ability in elite snow athletes

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    Change of direction ability (COD speed) is an important physical component of snow sports. The aim of this study was to investigate the relationships between regular speed and vertical jumping ability, and COD speed in elite snow athletes. Moreover, the correlations between relative mean propulsive power (assessed in the jump squat exercise) and COD speed were quantified. Sixteen elite snow sport athletes executed squat jumps, countermovement jumps, jump squats, and 25 m sprint tests, in addition to a Zig-zag change of direction speed test. The outcomes revealed that vertical jumping height and mean propulsive power are strongly correlated (r ≈ 0.90) with COD speed. Furthermore, snow athletes capable of sprinting faster in a linear course of 25 m performed better in COD speed tests ( r = 0.91). Our results support the use of loaded and unloaded vertical jumping and regular speed tests to evaluate/monitor predictors of COD speed in elite snow athletes. Finally, these relationships suggest that plyometrics and regular speed training should be considered by coaches as effective strategies to enhance COD ability in this specific group of subjects

    Pemetrexed enhances membrane PD-L1 expression and potentiates T cell-mediated cytotoxicity by anti-PD-L1 antibody therapy in non-small-cell lung cancer

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    Immunotherapy has significantly changed the treatment landscape for advanced non-small-cell lung cancer (NSCLC) with the introduction of drugs targeting programmed cell death protein-1 (PD-1) and programmed cell death ligand-1 (PD-L1). In particular, the addition of the anti-PD-1 antibody pembrolizumab to platinum-pemetrexed chemotherapy resulted in a significantly improved overall survival in patients with non-squamous NSCLC, regardless of PD-L1 expression. In this preclinical study, we investigated whether chemotherapy can modulate PD-L1 expression in non-squamous NSCLC cell lines, thus potentially affecting immunotherapy efficacy. Among different chemotherapeutic agents tested, only pemetrexed increased PD-L1 levels by activating both mTOR/P70S6K and STAT3 pathways. Moreover, it also induced the secretion of cytokines, such as IFN-γ and IL-2, by activated peripheral blood mononuclear cells PBMCs that further stimulated the expression of PD-L1 on tumor cells, as demonstrated in a co-culture system. The anti-PD-1/PD-L1 therapy enhanced T cell-mediated cytotoxicity of NSCLC cells treated with pemetrexed and expressing high levels of PD-L1 in comparison with untreated cells. These data may explain the positive results obtained with pemetrexed-based chemotherapy combined with pembrolizumab in PD-L1-negative NSCLC and can support pemetrexed as one of the preferable chemotherapy partners for immunochemotherapy combination regimens

    Soluble PD-L1 and Circulating CD8+PD-1+ and NK Cells Enclose a Prognostic and Predictive Immune Effector Score in Immunotherapy Treated NSCLC patients

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    Introduction: Upfront criteria to foresee immune checkpoint inhibitors (ICIs) efficacy are far from being identified. Thus, we integrated blood descriptors of pro-inflammatory/immunosuppressive or effective anti-tumor response to non-invasively define predictive immune profiles in ICI-treated advanced non-small cell lung cancer (NSCLC). Methods: Peripheral blood (PB) was prospectively collected at baseline from 109 consecutive NSCLC patients undergoing ICIs as first or more line treatment. Soluble PD-L1 (sPD-L1) (immunoassay), CD8+PD-1+ and NK (FACS) cells were assessed and interlaced to generate an Immune effector Score (IeffS). Lung Immune Prognostic Index (LIPI) was computed by LDH levels and derived Neutrophil-to-Lymphocyte Ratio (dNLR). All these parameters were correlated with survival outcome and treatment response. Results: High sPD-L1 and low CD8+PD-1+ and NK number had negative impact on PFS (P < 0.001), OS (P < 0.01) and ICI-response (P < 0.05). Thus, sPD-L1high, CD8+PD-1+low and NKlow were considered as risk factors encompassing IeffS, whose prognostic power outperformed that of individual features and slightly exceeded that of LIPI. Accordingly, the absence of these risk factors portrayed a favorable IeffS characterizing patients with significantly (P < 0.001) prolonged PFS (median NR vs 2.3 months) and OS (median NR vs 4.1) and greater benefit from ICIs (P < 0.01). We then combined each risk parameter composing IeffS and LIPI (LDHhigh, dNLRhigh), thus defining three distinct prognostic classes. A remarkable impact of IeffS-LIPI integration was documented on survival outcome (PFS, HR = 4.61; 95%CI = 2.32-9.18; P < 0.001; OS, HR=4.03; 95%CI=1.91-8.67; P < 0.001) and ICI-response (AUC=0.90, 95%CI=0.81-0.97, P < 0.001). Conclusion: Composite risk models based on blood parameters featuring the tumor-host interaction might provide accurate prognostic scores able to predict ICI benefit in NSCLC patients

    Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials

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    Quantum ESPRESSO is an integrated suite of computer codes for electronic-structure calculations and materials modeling, based on density-functional theory, plane waves, and pseudopotentials (norm-conserving, ultrasoft, and projector-augmented wave). Quantum ESPRESSO stands for "opEn Source Package for Research in Electronic Structure, Simulation, and Optimization". It is freely available to researchers around the world under the terms of the GNU General Public License. Quantum ESPRESSO builds upon newly-restructured electronic-structure codes that have been developed and tested by some of the original authors of novel electronic-structure algorithms and applied in the last twenty years by some of the leading materials modeling groups worldwide. Innovation and efficiency are still its main focus, with special attention paid to massively-parallel architectures, and a great effort being devoted to user friendliness. Quantum ESPRESSO is evolving towards a distribution of independent and inter-operable codes in the spirit of an open-source project, where researchers active in the field of electronic-structure calculations are encouraged to participate in the project by contributing their own codes or by implementing their own ideas into existing codes.Comment: 36 pages, 5 figures, resubmitted to J.Phys.: Condens. Matte

    Heat and charge transport in H2O at ice-giant conditions from ab initio molecular dynamics simulations

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    The impact of the inner structure and thermal history of planets on their observable features, such as luminosity or magnetic field, crucially depends on the poorly known heat and charge transport properties of their internal layers. The thermal and electric conductivities of different phases of water (liquid, solid, and super-ionic) occurring in the interior of ice giant planets, such as Uranus or Neptune, are evaluated from equilibrium ab initio molecular dynamics, leveraging recent progresses in the theory and data analysis of transport in extended systems. The implications of our findings on the evolution models of the ice giants are briefly discussed

    A modified Ehrenfest formalism for efficient large-scale ab initio molecular dynamics

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    We present in detail the recently derived ab-initio molecular dynamics (AIMD) formalism [Phys. Rev. Lett. 101 096403 (2008)], which due to its numerical properties, is ideal for simulating the dynamics of systems containing thousands of atoms. A major drawback of traditional AIMD methods is the necessity to enforce the orthogonalization of the wave-functions, which can become the bottleneck for very large systems. Alternatively, one can handle the electron-ion dynamics within the Ehrenfest scheme where no explicit orthogonalization is necessary, however the time step is too small for practical applications. Here we preserve the desirable properties of Ehrenfest in a new scheme that allows for a considerable increase of the time step while keeping the system close to the Born-Oppenheimer surface. We show that the automatically enforced orthogonalization is of fundamental importance for large systems because not only it improves the scaling of the approach with the system size but it also allows for an additional very efficient parallelization level. In this work we provide the formal details of the new method, describe its implementation and present some applications to some test systems. Comparisons with the widely used Car-Parrinello molecular dynamics method are made, showing that the new approach is advantageous above a certain number of atoms in the system. The method is not tied to a particular wave-function representation, making it suitable for inclusion in any AIMD software package.Comment: 28 pages, 5 figures, published in a special issue of J. Chem. Theory Comp. in honour of John Perde

    Behavioral and Chemical Ecology of Marine Organisms with Respect to Tetrodotoxin

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    The behavioral and chemical ecology of marine organisms that possess tetrodotoxin (TTX) has not been comprehensively reviewed in one work to date. The evidence for TTX as an antipredator defense, as venom, as a sex pheromone, and as an attractant for TTX-sequestering organisms is discussed. Little is known about the adaptive value of TTX in microbial producers; thus, I focus on what is known about metazoans that are purported to accumulate TTX through diet or symbioses. Much of what has been proposed is inferred based on the anatomical distribution of TTX. Direct empirical tests of these hypotheses are absent in most cases

    Circulating Pneumolysin Is a Potent Inducer of Cardiac Injury during Pneumococcal Infection

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    Streptococcus pneumoniae accounts for more deaths worldwide than any other single pathogen through diverse disease manifestations including pneumonia, sepsis and meningitis. Life-threatening acute cardiac complications are more common in pneumococcal infection compared to other bacterial infections. Distinctively, these arise despite effective antibiotic therapy. Here, we describe a novel mechanism of myocardial injury, which is triggered and sustained by circulating pneumolysin (PLY). Using a mouse model of invasive pneumococcal disease (IPD), we demonstrate that wild type PLY-expressing pneumococci but not PLY-deficient mutants induced elevation of circulating cardiac troponins (cTns), well-recognized biomarkers of cardiac injury. Furthermore, elevated cTn levels linearly correlated with pneumococcal blood counts (r=0.688, p=0.001) and levels were significantly higher in non-surviving than in surviving mice. These cTn levels were significantly reduced by administration of PLY-sequestering liposomes. Intravenous injection of purified PLY, but not a non-pore forming mutant (PdB), induced substantial increase in cardiac troponins to suggest that the pore-forming activity of circulating PLY is essential for myocardial injury in vivo. Purified PLY and PLY-expressing pneumococci also caused myocardial inflammatory changes but apoptosis was not detected. Exposure of cultured cardiomyocytes to PLY-expressing pneumococci caused dose-dependent cardiomyocyte contractile dysfunction and death, which was exacerbated by further PLY release following antibiotic treatment. We found that high PLY doses induced extensive cardiomyocyte lysis, but more interestingly, sub-lytic PLY concentrations triggered profound calcium influx and overload with subsequent membrane depolarization and progressive reduction in intracellular calcium transient amplitude, a key determinant of contractile force. This was coupled to activation of signalling pathways commonly associated with cardiac dysfunction in clinical and experimental sepsis and ultimately resulted in depressed cardiomyocyte contractile performance along with rhythm disturbance. Our study proposes a detailed molecular mechanism of pneumococcal toxin-induced cardiac injury and highlights the major translational potential of targeting circulating PLY to protect against cardiac complications during pneumococcal infections
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