Characterisation of beam driven ionisation injection in the blowout regime of Plasma Acceleration

Beam driven ionisation injection is characterised for a variety of high-Z dopant. We discuss the region of extraction and why the position where electrons are captured influences the final quality of the internally-injected bunch. The beam driven ionisation injection relies on the capability to produce a high gradient fields at the bubble closure, with magnitudes high enough to ionise by tunnelling effect the still bounded electrons (of a high-Z dopant). The ionised electrons are captured by the nonlinear plasma wave at the accelerating and focusing wake phase leading to high-brightness trailing bunches. The high transformer ratio guarantees that the ionisation only occurs at the bubble closure. The quality of the ionisation-injected trailing bunches strongly and non-linearly depends on the properties of the dopant gas (density and initial ionisation state). We use the full 3D PIC code ${\tt ALaDyn}$ to consider the highly three-dimensional nature of the effect. By means of a systematic approach we have investigated the emittance and energy spread formation and the evolution for different dopant gases and configurations

Hydrogen peroxide-mediated killing of Caenorhabditis elegans by Enterococcus italicus and Lactococcus garvieae isolated from food

In this study, we used the nematode Caenorhabditis elegans as a model to assess the pathogenic potential of two species isolated from food, Enterococcus italicus and Lactococcus garvieae, for which few indications on pathogenicity are available. We identified the conditions under which E. italicus and L. garvieae are able to kill the nematode and suggest that the production of hydrogen peroxide (H2O2) by these two bacteria was involved in the death of C. elegans in our model system. The efficacy of E. italicus and L. garvieae to kill C. elegans differed, most likely related to each species' distinct ability to accumulate H2O2 (4.9 mM and 0.9–1.1 mM, respectively). Genome analysis of both species revealed that the genome of E. italicus contains a gene encoding a NADH oxidase which shows high amino acidic similarity with H2O2 -forming NOX-1 enzymes, while that of L. garvieae contains a gene codifying for a water-forming NADH-oxidase (NOX-2). Reverse transcriptase-PCR experiments carried out in presence of flavin adenine dinucleotide (50 mM) confirmed the presence of the two different genes and likely explains the different toxicity of E. italicus and L. garvieae against C. elegans in our study. The results obtained show for the first time the production of H2O2 in E. italicus and L. garvieae and indicate its toxic effect in the nematode C. elegans

Synthesis and Characterization of Thermoelectric Co2XSn (X = Zr, Hf) Heusler Alloys

In this work, we report the results of an experimental investigation on the synthesis, structure, microstructure, mechanical, electrical conductivity, and Seebeck coefficient of Co2XSn (X = Zr, Hf) alloys. In both the alloys, the main constituent is a full Heusler-type compound that coexists with small amounts of secondary phases. Both alloys show a rather high Vickers hardness (around 900 HV) and an indentation fracture toughness typical of ceramics (around 2 MPa·m1/2). The electronic transport properties of the two alloys were measured for the first time. The temperature dependence of both the Seebeck coefficient and the electrical conductivity of the two alloys shows a change in correspondence of the Curie temperature. The Seebeck coefficient reaches a constant plateau, while the electrical conductivities show a transition from metallic to semiconductor behavior. As a consequence, almost constant values of the power factor have been obtained for the power factor above the Curie temperature, which is promising for an efficient exploitation of thermal gradients of several hundreds of degree in waste heat harvesting applications. Finally, on the basis of results from this work and from the literature, the effect of the substitution of the X element on the electronic transport properties in the series Co2XSn (X = Ti, Zr, Hf) is discussed

Efficient plasma wakefield acceleration simulations via kinetic-hydro code

Start-to-end simulations are needed for sensitivity stud- ies and online analysis of experimental data of the Plasma Wakefield Acceleration experiment COMB at SPARC_LAB facility, Frascati (Italy). Ad hoc tools are needed for the plasma section modeling. Particle in cell codes are the most widely used tools for this purpose, but they suffer from the considerable amount of computational resources they re- quire. We seek for a simple, portable, quick-to-run approach. For this purpose we introduce a time-explicit cylindrical hybrid fluid-kinetic code: Architect. The beam particles are treated with PIC-like kinetic approach, while the plasma wake is treated as a fluid. Since the number of computational particles used by the hybrid model is significantly reduced with respect of full PIC codes with the same number of di- mensions, the time required for a simulation is reduced as well

Influence of Magnesium as a Major Contributor of Water Hardness on Some Cardiac Disease Risk Factors

Various ecological studies report a reduction in cardiovascular disease mortality risk with increasing magnesium levels in drinking water. Most of the studies done in this field were epidemiologic studies.The aim of the present study was to examine whether magnesium addition to drinking water can affect risks of cardiac disease. The study included five groups of male albino rats. The rats received either tap water or water containing 5, 10, 20 g of magnesium sulfate per liter. During the whole experiment, all the groups received hypercholesterolemic diet except for the normal control which received normal basal diet. At the end of the experiment, blood was drawn for the determination of plasma magnesium, lipid profile and liver function. In addition, the extent of obesity was determined using the body mass index (BMI). In all groups magnesium addition was associated with higher levels of plasma magnesium. The blood analysis showed a significant decrease in serum total cholesterol, triglycerides, LDL- cholesterol and VLDL- cholesterol, while there was a significant increase in HDL- cholesterol in groups received magnesium sulfate in drinking water, compared with the hypercholesterolemic group received tap water. GOT, GPT and ALP followed the same trend. The addition of MgSO4 to the drinking water results in significant decrease in BMI of the magnesium treated groups relative to the hypercholesterolemic control. These results showed that high magnesium concentration in drinking water is capable of decreasing some cardiac disease risk factors in male albino rats. Keywords: Cardiac disease, hypercholesterolemia, Magnesium, Risk factors, Water

The independent and interactive effects of changes in overtime and night shifts during the COVID-19 pandemic on burnout among nurses: a longitudinal study

Objectives: This study aimed to evaluate the independent and interactive effects of changes in overtime and night shifts on burnout among nurses during the COVID-19 pandemic. Methods: Nurses working in an Italian university hospital (N=317) completed the Maslach Burnout Inventory in September 2019 and again in December 2020. Based on hospital administrative data, changes in overtime and night shifts in the same years were categorized into three groups each. Linear regressions were used to estimate 2020 burnout differences between exposure groups, controlling for 2019 burnout levels, demographic and work-related characteristics, and to test the interaction between the two exposures. Results: Nurses in the onset of high overtime group had higher emotional exhaustion [4.33, 95% confidence interval (CI) 1.74-6.92], depersonalization (2.10, 95% CI 0.49-3.71), and poor personal accomplishment (2.64, 95% CI 0.55-4.74) compared to stable low overtime nurses. Nurses in the increase in night shifts group had lower emotional exhaustion (-4.49, 95% CI -7.46- -1.52) compared to no night shift nurses. Interaction analyses revealed that this apparently paradoxical effect was limited to stable low overtime nurses only. Moreover, increases in night shifts were associated with higher depersonalization and poor personal accomplishment in nurses in the stable high overtime group. Conclusions: Increase in overtime is an independent risk factor for burnout among nurses, highlighting the need for specific regulations and actions to address it. Long-standing guidelines for the assignment of night shifts might have contributed to attenuate the impact of their increase on nurses' mental health

The North Italian Longitudinal Study Assessing the Mental Health Effects of SARS-CoV-2 Pandemic on Health Care Workers-Part I: Study Design and Psychometric Structural Validity of the HSE Indicator Tool and Work Satisfaction Scale

Literature on the impact of the SARS-CoV-2 pandemic on the mental health of Health Care Workers (HCWs) is mostly based on cross-sectional surveys. We designed a longitudinal study to assess work-related stress and mental health before and after the pandemic onset in a university-hospital in Lombardia region, Italy. We report on sample representativeness and structural validity of questionnaires assessing work stress (HSE Indicator Tool, HSE-IT) and work satisfaction (WS), which were not validated in the HCWs population. n = 1287 HCWs from 67 hospital wards/offices were invited to an online survey in summer 2019 (pre-COVID-19 wave) and again during winter 2020 (COVID-19 wave). Selected hospital wards/offices did not differ from the remaining wards for turn-over and down-sizing rates, overload, sick leaves, and night shifts (Wilcoxon rank tests p-values > 0.05). Participation rates were 70% (n = 805) and 60% (n = 431) in the pre-COVID-19 and COVID-19 waves, respectively. Socio-demographic and work-related characteristics did not impact data completeness nor participation to the COVID-19 wave. While confirming a 7-component structure for HSE-IT, we identified a new factor related to participation in work organization. A one-factor model for WS had satisfactory fit. Our longitudinal study based on a representative sample and adopting validated questionnaires is well-suited to elucidate the role of work conditions on the development of mental health disorders in HCWs