Surface Instability and Chemical Reactivity of ZrSiS and ZrSiSe Nodal-Line Semimetals

Materials exhibiting nodal-line fermions promise superb impact on technology for the prospect of dissipationless spintronic devices. Among nodal-line semimetals, the ZrSiX (X = S, Se, Te) class is the most suitable candidate for such applications. However, the surface chemical reactivity of ZrSiS and ZrSiSe has not been explored yet. Here, by combining different surface-science tools and density functional theory, it is demonstrated that the formation of ZrSiS and ZrSiSe surfaces by cleavage is accompanied by the washing up of the exotic topological bands, giving rise to the nodal line. Moreover, while the ZrSiS has a termination layer with both Zr and S atoms, in the ZrSiSe surface, reconstruction occurs with the appearance of Si surface atoms, which is particularly prone to oxidation. It is demonstrated that the chemical activity of ZrSiX compounds is mostly determined by the interaction of the Si layer with the ZrX sublayer. A suitable encapsulation for ZrSiX should not only preserve their surfaces from interaction with oxidative species, but also provide a saturation of dangling bonds with minimal distortion of the surface. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimU.S. Department of Energy, USDOE: DE-SC0014208A.P. thanks Elettra Sincrotrone Trieste S.C.p.A. for financial support. Z.M. thanks the support by the U.S. Department of Energy under grant DE-SC0014208 for material synthesis. This work was partly performed in the framework of the Nanoscience Foundry and Fine Analysis facility (NFFA-MIUR Italy Progetti Internazionali)

Liposomes loaded with bioactive lipids enhance antibacterial innate immunity irrespective of drug resistance

Phagocytosis is a key mechanism of innate immunity, and promotion of phagosome maturation may represent a therapeutic target to enhance antibacterial host response. Phagosome maturation is favored by the timely and coordinated intervention of lipids and may be altered in infections. Here we used apoptotic body-like liposomes (ABL) to selectively deliver bioactive lipids to innate cells, and then tested their function in models of pathogen-inhibited and host-impaired phagosome maturation. Stimulation of macrophages with ABLs carrying phosphatidic acid (PA), phosphatidylinositol 3-phosphate (PI3P) or PI5P increased intracellular killing of BCG, by inducing phagosome acidification and ROS generation. Moreover, ABLs carrying PA or PI5P enhanced ROS-mediated intracellular killing of Pseudomonas aeruginosa, in macrophages expressing a pharmacologically-inhibited or a naturally-mutated cystic fibrosis transmembrane conductance regulator. Finally, we show that bronchoalveolar lavage cells from patients with drug-resistant pulmonary infections increased significantly their capacity to kill in vivo acquired bacterial pathogens when ex vivo stimulated with PA-or PI5P-loaded ABLs. Altogether, these results provide the proof of concept of the efficacy of bioactive lipids delivered by ABL to enhance phagosome maturation dependent antimicrobial response, as an additional host-directed strategy aimed at the control of chronic, recurrent or drug-resistant infections

Uso sinergico della reologia e della risonanza magnetica nucleare a basso campo per caratterizzare l’espettorato di pazienti con fibrosi cistica

Hyper-concentrated and more viscous mucus presents in the lungs of patients suffering from cystic fibrosis (CF) provoke mucus stasis providing an optimal environment for bacterial growth. The sputum of CF patients has been subjected to rheological and low-field NMR investigation, providing information on i) the state of viscoelasticity (G0, h 0 ) and mucus hydration (T2avg), ii) possible correlations also with parameter of patients clinical status given by spirometry(FEV1) iii) the structure of the polymeric network in mucus. The absence of correlation among magnetic and mechanical-rheological relaxation notes that these phenomena are linked to different aspects of sputum. However, correlations exist among FEV1, T2av and rheological properties G0, h 0. Moreover, T2avg correlates with the mucociliary clearability index (MCI) and cough clearability index (CCI), two indices derived from the rheological characterization. The clinical condition of the patient can, therefore, be summarized by T2avg alone. Finally, information from the two characterizations make it possible to estimate the mesh size distribution of the polymeric network pervading sputum. This knowledge is very useful to better understand drugs penetration in mucus

Underwater intervention robotics: An outline of the Italian national project Maris

The Italian national project MARIS (Marine Robotics for Interventions) pursues the strategic objective of studying, developing, and integrating technologies and methodologies to enable the development of autonomous underwater robotic systems employable for intervention activities. These activities are becoming progressively more typical for the underwater offshore industry, for search-and-rescue operations, and for underwater scientific missions. Within such an ambitious objective, the project consortium also intends to demonstrate the achievable operational capabilities at a proof-of-concept level by integrating the results with prototype experimental systems

Spin injection in the doped bad metal SrTiO3

In this paper, we demonstrate the capability to establish spin-polarized currents in doped SrTiO3 (STO). The results are based on the study of charge and spin transport in STO layers doped by the reversible electromigration of oxygen atoms in resistive-switching La0.7Sr0.3MnO3/STO/Co vertical stacks. The formation of oxygen vacancies inside STO results in a metallic conductivity at temperatures <200–250 K, above which a transitionto an insulating like behavior is detected. A detailed theoretical analysis shows that the behavior of the metallic phase in our samples corresponds to the well-known state of the thermodynamically doped STO featuring the so-called bad metal behavior. Thus, our findings introduce this class of unconventional materials as valuable candidates for innovative spintronic devices

Italian guidelines for primary headaches: 2012 revised version

The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105–190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version

Alcohol drinking and head and neck cancer risk: the joint effect of intensity and duration

Background: Alcohol is a well-established risk factor for head and neck cancer (HNC). This study aims to explore the effect of alcohol intensity and duration, as joint continuous exposures, on HNC risk. Methods: Data from 26 case-control studies in the INHANCE Consortium were used, including never and current drinkers who drunk ≤10 drinks/day for ≤54 years (24234 controls, 4085 oral cavity, 3359 oropharyngeal, 983 hypopharyngeal and 3340 laryngeal cancers). The dose-response relationship between the risk and the joint exposure to drinking intensity and duration was investigated through bivariate regression spline models, adjusting for potential confounders, including tobacco smoking. Results: For all subsites, cancer risk steeply increased with increasing drinks/day, with no appreciable threshold effect at lower intensities. For each intensity level, the risk of oral cavity, hypopharyngeal and laryngeal cancers did not vary according to years of drinking, suggesting no effect of duration. For oropharyngeal cancer, the risk increased with durations up to 28 years, flattening thereafter. The risk peaked at the higher levels of intensity and duration for all subsites (odds ratio = 7.95 for oral cavity, 12.86 for oropharynx, 24.96 for hypopharynx and 6.60 for larynx). Conclusions: Present results further encourage the reduction of alcohol intensity to mitigate HNC risk