Vibrational stability of graphene under combined shear and axial strains

We study the vibrational properties of graphene under combined shear and uniaxial tensile strain using density-functional perturbation theory. Shear strain always causes rippling instabilities with strain-dependent direction and wavelength; armchair strain contrasts this instability, enabling graphene stability in a large range of combined strains. A complementary description based on membrane elasticity theory nicely clarifies the competition of shear-induced instability and uniaxial tension. We also report the large strain-induced shifts of the split components of the G optical phonon line, which may serve as a shear diagnostic. As to the electronic properties, we find that conical intersections move away from the Brillouin zone border under strain, and they tend to coalesce at large strains, making the opening of gaps difficult to assess. By a detailed search, we find that even at large strains, only small gaps in the tens-of-meV range open at the former Dirac points.Comment: 6 pages, 11 figure

Gap opening in graphene by shear strain

We exploit the concept of strain-induced band structure engineering in graphene through the calculation of its electronic properties under uniaxial, shear, and combined uniaxial-shear deformations. We show that by combining shear deformations to uniaxial strains it is possible modulate the graphene energy gap value from zero up to $0.9$ eV. Interestingly enough, the use of a shear component allows for a gap opening at moderate absolute deformation, safely smaller than the graphene failure strain.Comment: to appear on PRB - Rapid Communicatio

Haemolymphatic cancer among children in Sardinia, Italy: 1974–2003 incidence

Objectives To explore the time trend and geographical distribution of childhood leukaemia incidence over the territory of the Italian region of Sardinia.Setting All hospitals departments, diagnostic centres and social security agencies in Sardinia were regularly screened in 1974–2003 to identify, register and review the diagnoses of incident cases of haematological malignancies (HM).Participants The whole child population aged 0–14 resident in Sardinia.Primary and secondary outcome measures Incidence and time trend of childhood HM and childhood acute lymphoblastic leukaemia (ALL) over the study period, and use of Bayesian methods to plot the probability of areas with excess incidence on the regional map.Results Overall, 675 HM cases, including 378 ALL cases, occurred among children aged 0–14 years resident in Sardinia in 1974–2003, with an incidence rate of 6.97×10-5 (95% CI 6.47 to 7.51) and 3.85×10-5 (95% CI 3.48 to 4.26), respectively. Incidence of HM and ALL showed an upward trend along the study period especially among females. Three communes out of the 356 existing in 1974, namely Ittiri, Villa San Pietro and Carbonia, stand out as areas with excess incidence of HM and ALL in particular and another, Carloforte, for ALL only.Conclusions Our results might serve as convincing arguments for extending the coverage of routine cancer registration over the whole Sardinian population, while prompting further research on the genetic and environmental determinants in the areas at risk

Variation of the Myelin Oligodendrocyte Glycoprotein gene is not primarily associated with multiple sclerosis in the Sardinian population

Background. Multiple sclerosis (MS) is consistently associated with particular HLA-DRB1-DQB1 haplotypes. However, existing evidence suggests that variation at these loci does not entirely explain association of the HLA region with the disease. The MOG locus is a prime positional and functional candidate for such additional predisposing effects but the analysis is complicated by the strong, albeit labyrinthine pattern of linkage disequilibrium in the region. Here we have assessed the association of MOG variation with MS in the Sardinian population to see if it represents an independent contributor to MS predisposition. Results. After re-sequencing the MOG gene in 21 healthy parents of MS patients we detected 134 variants, 33 of which were novel. A set of 40 informative SNPs was then selected and assessed for disease association together with 1 intragenic microsatellite in an initial data set of 239 MS families. This microsatellite and 11 SNPs were found to be positively associated with MS, using the transmission disequilibrium test, and were followed up in an additional 158 families (total families analysed = 397). While in these 397 families, 8 markers showed significant association with MS, through conditional tests we determined that these MOG variants were not associated with MS independently of the main DRB1-DQB1 disease associations. Conclusion. These results indicate that variation within the MOG gene is not an important independent determinant of MS-inherited risk in the Sardinian population

Ultrasound imaging of the axilla

: Axilla is a pyramidal-in-shape "virtual cavity" housing multiple anatomical structures and connecting the upper limb with the trunk. To the best of our knowledge, in the pertinent literature, a detailed sonographic protocol to comprehensively assess the axillary region in daily practice is lacking. In this sense, the authors have briefly described the anatomical architecture of the axilla-also using cadaveric specimens-to propose a layer-by-layer sonographic approach to this challenging district. The most common sonographic pathological findings-for each and every anatomical compartment of the axilla-have been accurately reported and compared with the corresponding histopathological features. This ultrasound approach could be considered a ready-to-use educational guidance for the assessment of the axillary region. CRITICAL RELEVANCE STATEMENT: Axilla is a pyramidal-in-shape "virtual cavity" housing multiple anatomical structures and connecting the upper limb with the trunk. The aim of this review article was to describe the anatomical architecture of the axilla, also using cadaveric specimens, in order to propose a layer-by-layer sonographic approach to this challenging district

Management of hepatitis B virus prophylaxis in patients treated with disease-modifying therapies for multiple sclerosis: a multicentric Italian retrospective study

Background: Patients with multiple sclerosis (MS) often receive disease-modifying therapies (DMTs) that can expose them to reactivation of potential occult hepatitis B virus (HBV) infection (pOBI). We aimed to evaluate the MS Centers behavior regarding HBV screening and prophylaxis in a large cohort of MS patients receiving anti-CD20 or cladribine. Methods: Retrospective, multicentric study recruiting Italian MS patients treated with rituximab, ocrelizumab and cladribine. Results: We included 931 MS patients from 15 centers. All but 38 patients performed a complete HBV screening. Patients' age > 50 years was significantly associated with no history of vaccination and HBsAb titres < 100 mIU at baseline (p < 0.001). No significant correlation was found between post-vaccination HBsAb titres and type of treatment (p = 0.5), pre-or post-therapy vaccination (p = 0.2) and number of previous DMTs (p = 0.2). Among pOBI patients (n = 53), 21 received antiviral prophylaxis, while only 13 had HBV DNA monitoring and 19 patients neither monitored HBV DNA nor received prophylaxis. Conclusions: Baseline HBV screening in patients receiving anti-CD20 and cladribine is a consolidated practice. Nonetheless, HBV vaccination coverage is still lacking in such population and age is a significant factor associated with low HBV protection. Rituximab, ocrelizumab and cladribine did not impair HBV vaccine response. Almost 35% of pOBI patients fail to receive HBVr prevention. Management of HBV prophylaxis could be improved in MS patients and further prospective studies are needed to assess the effectiveness of prophylactic strategies in such patients

Notulae to the Italian alien vascular flora: 11

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1

A machine-learning based bio-psycho-social model for the prediction of non-obstructive and obstructive coronary artery disease

Background: Mechanisms of myocardial ischemia in obstructive and non-obstructive coronary artery disease (CAD), and the interplay between clinical, functional, biological and psycho-social features, are still far to be fully elucidated. Objectives: To develop a machine-learning (ML) model for the supervised prediction of obstructive versus non-obstructive CAD. Methods: From the EVA study, we analysed adults hospitalized for IHD undergoing conventional coronary angiography (CCA). Non-obstructive CAD was defined by a stenosis < 50% in one or more vessels. Baseline clinical and psycho-socio-cultural characteristics were used for computing a Rockwood and Mitnitski frailty index, and a gender score according to GENESIS-PRAXY methodology. Serum concentration of inflammatory cytokines was measured with a multiplex flow cytometry assay. Through an XGBoost classifier combined with an explainable artificial intelligence tool (SHAP), we identified the most influential features in discriminating obstructive versus non-obstructive CAD. Results: Among the overall EVA cohort (n = 509), 311 individuals (mean age 67 ± 11 years, 38% females; 67% obstructive CAD) with complete data were analysed. The ML-based model (83% accuracy and 87% precision) showed that while obstructive CAD was associated with higher frailty index, older age and a cytokine signature characterized by IL-1β, IL-12p70 and IL-33, non-obstructive CAD was associated with a higher gender score (i.e., social characteristics traditionally ascribed to women) and with a cytokine signature characterized by IL-18, IL-8, IL-23. Conclusions: Integrating clinical, biological, and psycho-social features, we have optimized a sex- and gender-unbiased model that discriminates obstructive and non-obstructive CAD. Further mechanistic studies will shed light on the biological plausibility of these associations. Clinical trial registration: NCT02737982