250 research outputs found

    ANALYSIS OF STORED DATA HELP TO PROPOSE AND GENERATE NEW TRACKS

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    During experiments on vehicle simulators a large amount of data is stored. On these data, it is possible to trace some similarities in the behavior of drivers in certain areas or when performing the same task. We can assume that if the driver performs a certain type of experiment, his behavior exhibits certain traits. These elements of common behavior can be used to create virtual track forexperiments. Which elements and how they can be used is described in this article. The algorithm for automatic creation of virtual track based on type of experiment is provided. It will help us to define the purpose of measurement and the track could be generated automatically

    The Declining Enrollment of San Diego County High School Music Programs from 2006-2021

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    Since 2006, many San Diego County High Schools have experienced a dramatic decline in music program enrollment. The effects of the COVID-19 pandemic and the new teaching paradigm served as catalysts that caused some San Diego County high schools to discontinue their music programs entirely. The enrollment statistics for San Diego County high school music programs during the fifteen years from 2006-2021 fall far below the national average. The effects of these changes have left many students and communities with either a struggling music program or without a music program at all. This case study examined a set of San Diego County high school music programs from 2006-2021 to determine the internal and external causes for the decreased enrollment numbers. By examining these fifteen years, this study determined that the decline in enrollment was a trend, not an anomaly. The COVID-19 pandemic\u27s decline exacerbated the situation for students, teachers, and administrators. Further, this study identified the characteristics that distinguish the programs with sustained or increased enrollment from those with decreased enrollment. The study consisted of analyzing and evaluating enrollment data provided by the districts, festival and competition scores, and demographic data. These data were examined in light of leading literature on the subject and compared against the national averages

    Vitamin c—sources, physiological role, kinetics, deficiency, use, toxicity, and determination

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    Vitamin C (L‐ascorbic acid) has been known as an antioxidant for most people. However, its physiological role is much larger and encompasses very different processes ranging from facili-tation of iron absorption through involvement in hormones and carnitine synthesis for important roles in epigenetic processes. Contrarily, high doses act as a pro‐oxidant than an anti‐oxidant. This may also be the reason why plasma levels are meticulously regulated on the level of absorption and excretion in the kidney. Interestingly, most cells contain vitamin C in millimolar concentrations, which is much higher than its plasma concentrations, and compared to other vitamins. The role of vitamin C is well demonstrated by miscellaneous symptoms of its absence—scurvy. The only clini-cally well‐documented indication for vitamin C is scurvy. The effects of vitamin C administration on cancer, cardiovascular diseases, and infections are rather minor or even debatable in the general population. Vitamin C is relatively safe, but caution should be given to the administration of high doses, which can cause overt side effects in some susceptible patients (e.g., oxalate renal stones). Lastly, analytical methods for its determination with advantages and pitfalls are also discussed in this review

    Attenuation of doxorubicin-induced cardiotoxicity by mdivi-1: a mitochondrial division/mitophagy inhibitor

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    Doxorubicin is one of the most effective anti-cancer agents. However, its use is associated with adverse cardiac effects, including cardiomyopathy and progressive heart failure. Given the multiple beneficial effects of the mitochondrial division inhibitor (mdivi-1) in a variety of pathological conditions including heart failure and ischaemia and reperfusion injury, we investigated the effects of mdivi-1 on doxorubicin-induced cardiac dysfunction in naĂŻve and stressed conditions using Langendorff perfused heart models and a model of oxidative stress was used to assess the effects of drug treatments on the mitochondrial depolarisation and hypercontracture of cardiac myocytes. Western blot analysis was used to measure the levels of p-Akt and p-Erk 1/2 and flow cytometry analysis was used to measure the levels p-Drp1 and p-p53 upon drug treatment. The HL60 leukaemia cell line was used to evaluate the effects of pharmacological inhibition of mitochondrial division on the cytotoxicity of doxorubicin in a cancer cell line. Doxorubicin caused a significant impairment of cardiac function and increased the infarct size to risk ratio in both naĂŻve conditions and during ischaemia/reperfusion injury. Interestingly, co-treatment of doxorubicin with mdivi-1 attenuated these detrimental effects of doxorubicin. Doxorubicin also caused a reduction in the time taken to depolarisation and hypercontracture of cardiac myocytes, which were reversed with mdivi-1. Finally, doxorubicin caused a significant elevation in the levels of signalling proteins p-Akt, p-Erk 1/2, p-Drp1 and p-p53. Co-incubation of mdivi-1 with doxorubicin did not reduce the cytotoxicity of doxorubicin against HL-60 cells. These data suggest that the inhibition of mitochondrial fission protects the heart against doxorubicin-induced cardiac injury and identify mitochondrial fission as a new therapeutic target in ameliorating doxorubicin-induced cardiotoxicity without affecting its anti-cancer properties

    Oxygen reactions on Pt{hkl} in a non-aqueous Na+ electrolyte: site selective stabilisation of a sodium peroxy species

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    Sodium–oxygen battery cathodes utilise the reversible redox species of oxygen in the presence of sodium ions. However, the oxygen reduction and evolution reaction mechanism is yet to be conclusively determined. In order to examine the part played by surface structure in sodium–oxygen electrochemistry for the development of catalytic materials and structures, a method of preparing clean, well-defined Pt electrode surfaces for adsorption studies in aprotic solvents is described. Using cyclic voltammetry (CV) and in situ electrochemical shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS), the various stages of oxygen reduction as a function of potential have been determined. It is found that on Pt{111} and Pt{110}-(1 × 1) terraces, a long lived surface sodium peroxide species is formed reversibly, whereas on Pt{100} and polycrystalline electrodes, this species is not detected

    Boosting hydrogen evolution performance by using a plasma-sputtered porous monolithic W2C@WC1−x/Mo film electrocatalyst

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    The establishment of an efficient and economic means of producing hydrogen via electrocatalytic water-splitting will facilitate the extensive commercialization of fuel cells, and the round-the-clock model of electrocatalytic hydrogen production will alleviate the intermittency issue associated with sustainable energy sources. To enable this feature of renewable hydrogen energy, the key point is to develop cheap, large-scale and high-performance hydrogen evolution electrocatalysts as an alternative to noble metals. Here, a simple and robust physically sputtering strategy is reported to massively prepare a porous and defect-enriched W2C@WC1−x film electrocatalyst on carbon cloth (CC) in a W, C and Ar ion plasma atmosphere. The preferential re-sputtering mechanism promotes the loss of activated W and C ions in plasma and extracts more C from plasma, resulting in the ultimate formation of a defective W2C@WC1−x film. The ratio of W2C to WC1−x increased and the particle size decreased when additional nano-scale thickness Mo sublayers were further incorporated. A monolithic and porous W2C@WC1−x/Mo multilayer film as a binder-free electrocatalyst on flexible CC is created. It exhibits excellent HER performance with a low overpotential of 58 mV vs. RHE to drive a current density of −10 mA cm−2, a low Tafel slope of 41 mV dec−1 and over 6 days of long-term running stability in 0.5 M H2SO4 solution. It outperforms most of the recently reported outstanding non-noble metal electrocatalysts. This work sheds light on a new route to regulate the tungsten-carbide catalyst morphology and composition with an aim to boost its HER activity

    Oxygen reduction reaction features in neutral media on glassy carbon electrode functionalized by chemically prepared gold nanoparticles

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    Gold nanoparticles (AuNPs) were prepared by chemical route using 4 different protocols by varying reducer, stabilizing agent and solvent mixture. The obtained AuNPs were characterized by transmission electronic microscopy (TEM), UV-Visible and zeta potential measurements. From these latter surface charge densities were calculated to evidence the effect of the solvent mixture on AuNPs stability. The AuNPs were then deposited onto glassy carbon (GC) electrodes by drop-casting and the resulting deposits were characterized by cyclic voltammetry (CV) in H2SO4 and field emission gun scanning electron microscopy (FEG-SEM). The electrochemical kinetic parameters of the 4 different modified electrodes towards oxygen reduction reaction (ORR) in neutral NaCl-NaHCO3 media (0.15 M / 0.028 M, pH 7.4) were evaluated by rotating disk electrode voltammetry and subsequent Koutecky-Levich treatment. Contrary to what we previously obtained with electrodeposited AuNPs [Gotti et al., Electrochim. Acta 2014], the highest cathodic transfer coefficients were not obtained on the smallest particles, highlighting the influence of the stabilizing ligand together with the deposits morphology on the ORR kinetics
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