Temporal Variations in the Usefulness of Normalized Difference Vegetation Index as a Predictor for Ixodes ricinus (Acari: Ixodidae) in a Borrelia lusitaniae Focus in Tuscany, Central Italy

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Effects of Defects on Friction for a Xe Film Sliding on Ag(111)

The effects of a step defect and a random array of point defects (such as vacancies or substitutional impurities) on the force of friction acting on a xenon monolayer film as it slides on a silver (111) substrate are studied by molecular dynamic simulations and compared with the results of lowest order perturbation theory in the substrate corrugation potential. For the case of a step, the magnitude and velocity dependence of the friction force are strongly dependent on the direction of sliding respect to the step and the corrugation strength. When the applied force F is perpendicular to the step, the film is pinned forF less than a critical force Fc. Motion of the film along the step, however, is not pinned. Fluctuations in the sliding velocity in time provide evidence of both stick-slip motion and thermally activated creep. Simulations done with a substrate containing a 5 percent concentration of random point defects for various directions of the applied force show that the film is pinned for the force below a critical value. The critical force, however, is still much lower than the effective inertial force exerted on the film by the oscillations of the substrate in experiments done with a quartz crystal microbalance (QCM). Lowest order perturbation theory in the substrate potential is shown to give results consistent with the simulations, and it is used to give a physical picture of what could be expected for real surfaces which contain many defects.Comment: 13 pages, 17 figures, latex plus postscript files for figure

Strongly Temperature Dependent Sliding Friction for a Superconducting Interface

A sudden drop in mechanical friction, between an adsorbed nitrogen monolayer and a lead substrate, occurs when the lead passes through the superconducting transition temperature. We attribute this effect to a sudden drop at the superconducting transition temperature of the substrate Ohmic heating. The Ohmic heating is due to the electronic screening current that results from the sliding adsorbed film.Comment: Revte

Mesenchymal Stem Cells: The Secret Children’s Weapons against the SARS-CoV-2 Lethal Infection

Due to the promising effects of mesenchymal stem cells (MSCs) in the treatment of various diseases, this commentary aimed to focus on the auxiliary role of MSCs to reduce inflammatory processes of acute respiratory infections caused by the 2019 novel coronavirus (COVID-19). Since early in 2020, COVID-19, a consequence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly affected millions of people world-wide. The SARS-CoV-2 infection in children appears to be an unusual event. Despite the high number of affected adult and elderly, children and adolescents remained low in amounts, and marginally touched. Based on the promising role of cell therapy and regenerative medicine approaches in the treatment of several life-threatening diseases, it seems that applying MSCs cell-based approaches can also be a hopeful strategy for improving subjects with severe acute respiratory infections caused by COVID-19

Covid-19 and covid-like patients: A brief analysis and findings of two deceased cases

BACKGROUND: The predominant pattern of lung lesions in patients affected by coronavirus disease (COVID-19) disease is diffuse alveolar damage with massive thromboembolism similar as described in patients infected with severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronaviruses. Hyaline membrane formation and pneumocyte atypical hyperplasia were frequent. Importantly, the formation of platelet– fibrin thrombi in small vessels was seen consistent with coagulopathy, which appeared to be a common feature in patients who died of COVID-19. However, many were the cases found with similar COVID-19 symptomatology though negative results from nasal-pharyngeal swab performed by reverse transcription-polymerase chain reaction (RT-PCR). This latter typology of patients, otherwise named COVID-like, showed analogous clinical signs with similar arterial blood gas, cell blood count and laboratory parameters, and same computed tomography (CT)-scan ground-glass opacities. Symptoms such as cough, fever, and difficulty breathing were highly similar as well. Both forms, COVID-19 and COVID-like, are primarily respiratory with multi-organ involvement and both revealed comparable incubation periods often with a rapid onset and unexpected decay. CASE REPORT: In this brief paper, we described two cases regarding two deceased males, one confirmed COVID-19 (RT-PCR but not CT scan) and the second a COVID-like (negative for RT-PCR but positive to CT scan with ground-glass opacity) whom condition, disease patterns, and analysis were highly similar. CONCLUSION: Improved investigation is mandatory, in which RT-PCR and CT scan procedures are completed by data from more detailed laboratory analysis, ABG analysis, BALF, and a deeper clinical assessment

Radiative heat transfer between nanostructures

We simplify the formalism of Polder and Van Hove [Phys.Rev.B {\bf 4}, 3303(1971)], which was developed to calculate the heat transfer between macroscopic and nanoscale bodies of arbitrary shape, dispersive and adsorptive dielectric properties. In the non-retarded limit, at small distances between the bodies, the problem is reduced to the solution of an electrostatic problem. We apply the formalism to the study of the heat transfer between: (a) two parallel semi-infinite bodies, (b) a semi-infinite body and a spherical body, and (c) that two spherical bodies. We consider the dependence of the heat transfer on the temperature $T$, the shape and the separation $d$. We determine when retardation effects become important.Comment: 11 pages, 5 figure

Detection of Invasive Borrelia burgdorferi Strains in North-Eastern Piedmont, Italy.

SummaryFollowing reports of human cases of Lyme borreliosis from the Ossola Valley, a mountainous area of Piemonte, north‐western Italy, the abundance and altitudinal distribution of ticks, and infection of these vectors with Borrelia burgdorferi sensu lato were evaluated. A total of 1662 host‐seeking Ixodes ricinus were collected by dragging from April to September 2011 at locations between 400 and 1450 m above sea level. Additional 104 I. ricinus were collected from 35 hunted wild animals (4 chamois, 8 roe deer, 23 red deer). Tick density, expressed as the number of ticks per 100 m2, resulted highly variable among different areas, ranging from 0 to 105 larvae and from 0 to 22 nymphs. A sample of 352 ticks (327 from dragging and 25 from wild animals) was screened by a PCR assay targeting a fragment of the 16S rRNA gene of B. burgdorferi s.l. Positive samples were confirmed with a PCR assay specific for the 5S‐23S rRNA intergenic spacer region and sequenced. Four genospecies were found: B. afzelii (prevalence 4.0%), B. lusitaniae (4.0%), B. garinii (1.5%) and B. valaisiana (0.3%). Phylogenetic analysis based on the ospC gene showed that most of the Borrelia strains from pathogenic genospecies had the potential for human infection and for invasion of secondary body sites