Optical properties of two-dimensional tin nanosheets epitaxially grown on graphene

Heterostacks formed by combining two-dimensional materials show novel properties which are of great interest for new applications in electronics, photonics and even twistronics, the new emerging field born after the outstanding discoveries on twisted graphene. Here, we report the direct growth of tin nanosheets at the two-dimensional limit via molecular beam epitaxy on chemical vapor deposited graphene on Al2O3(0001). The mutual interaction between the tin nanosheets and graphene is evidenced by structural and chemical investigations. On the one hand, Raman spectroscopy indicates that graphene undergoes compressive strain after the tin growth, while no charge transfer is observed. On the other hand, chemical analysis shows that tin nanosheets interaction with sapphire is mediated by graphene avoiding the tin oxidation occurring in the direct growth on this substrate. Remarkably, optical measurements show that the absorption of tin nanosheets show a graphene-like behavior with a strong absorption in the ultraviolet photon energy range, therein resulting in a different optical response compared to tin nanosheets on bare sapphire. The optical properties of tin nanosheets therefore represent an open and flexible playground for the absorption of light in a broad range of the electromagnetic spectrum and technologically relevant applications for photon harvesting and sensors.Comment: 14 pages, 7 figure

Towards a Long-Read Sequencing Approach for the Molecular Diagnosis of RPGRORF15 Genetic Variants

Sequencing of the low-complexity ORF15 exon of RPGR, a gene correlated with retinitis pigmentosa and cone dystrophy, is difficult to achieve with NGS and Sanger sequencing. False results could lead to the inaccurate annotation of genetic variants in dbSNP and ClinVar databases, tools on which HGMD and Ensembl rely, finally resulting in incorrect genetic variants interpretation. This paper aims to propose PacBio sequencing as a feasible method to correctly detect genetic variants in low-complexity regions, such as the ORF15 exon of RPGR, and interpret their pathogenicity by structural studies. Biological samples from 75 patients affected by retinitis pigmentosa or cone dystrophy were analyzed with NGS and repeated with PacBio. The results showed that NGS has a low coverage of the ORF15 region, while PacBio was able to sequence the region of interest and detect eight genetic variants, of which four are likely pathogenic. Furthermore, molecular modeling and dynamics of the RPGR Glu-Gly repeats binding to TTLL5 allowed for the structural evaluation of the variants, providing a way to predict their pathogenicity. Therefore, we propose PacBio sequencing as a standard procedure in diagnostic research for sequencing low-complexity regions such as RPGRORF15, aiding in the correct annotation of genetic variants in online databases

Course and Lethality of SARS-CoV2 Epidemic in Nursing Homes after Vaccination in Florence, Italy

Evidence on the effectiveness of SARS-CoV-2 vaccines in nursing home (NHs) residents is limited. We examined the impact of the BNT162b2 mRNA SARS-CoV-2 vaccine on the course of the epidemic in NHs in the Florence Health District, Italy, before and after vaccination. Moreover, we assessed survival and hospitalization by vaccination status in SARS-CoV-2-positive cases occurring during the post-vaccination period. We calculated the weekly infection rates during the pre-vaccination (1 October–26 December 2020) and post-vaccination period (27 December 2020–31 March 2021). Cox analysis was used to analyze survival by vaccination status. The study involved 3730 residents (mean age 84, 69% female). Weekly infection rates fluctuated during the pre-vaccination period (1.8%–6.5%) and dropped to zero during the post-vaccination period. Nine unvaccinated (UN), 56 partially vaccinated (PV) and 35 fully vaccinated (FV) residents tested SARS-CoV-2+ during the post-vaccination period. FV showed significantly lower hospitalization and mortality rates than PV and UV (hospitalization: FV 3%, PV 14%, UV 33%; mortality: FV 6%, PV 18%, UV 56%). The death risk was 84% and 96% lower in PV (HR 0.157, 95%CI 0.049–0.491) and FV (HR 0.037, 95%CI 0.006–0.223) versus UV. SARS-CoV-2 vaccination was followed by a marked decline in infection rates and was associated with lower morbidity and mortality among infected NH residents

Detection of the Emerging Rotavirus G9 Serotype at High Frequency in Italy

Group A human rotavirus strains belonging to the unusual serotype G9 were detected at high frequency in stool specimens from infected children with acute diarrhea in Bari, Italy, during a 15-month survey from March 2001 to June 2002. This may signify a local reemergence of the G9 rotaviruses detected in Italy in the early and mid-1990s or may be related to the global emergence of G9 rotaviruses in recent years

Does a parent-reported history of pneumonia increase the likelihood of respiratory symptoms needing therapy in asthmatic children and adolescents?

Background. Asthmatic children and adolescents attending outpatient clinics often have a history of pneumonia. Whether respiratory symptoms, lung function, and airway inflammation differ in asthmatic patients with and without a history of pneumonia remains controversial. Aims. To compare clinical, lung functional, and inflammatory variables in asthmatic outpatients with and without a history of pneumonia. Methods. In 190 asthmatic outpatients, aged 6-18 years, we assessed respiratory symptoms, lung function (flows, volumes, and pulmonary diffusion capacity, DLCO/VA), and atopic-airway inflammation as measured by the fractional concentration of exhaled nitric oxide (FENO). A previous medical and radiological diagnosis of pneumonia was defined as "recurrent pneumonia" if subjects had at least three pneumonia episodes or two episodes within a year. Results. Of the 190 outpatients studied, 38 (20%) had a history of pneumonia. These patients had more frequent upper-respiratory symptoms, nighttime awakenings in the past 4 weeks, daily use of inhaled corticosteroids, and lower FENO than the 152 asthmatic children without previous pneumonia (FENO: 20.6 ppb, 95% CI: 15.2-28.0 vs. 31.1 ppb, 95% CI: 27.0-35.8; p < .05). Of the 38 patients with previous pneumonia, 14 had recurrent pneumonia. Despite comparable lung volumes and flows, they also had lower DLCO/VA than asthmatic children with no recurrent pneumonia and asthmatic children without previous pneumonia (DLCO/VA%: 91.2 +/- 11.3 vs. 108.5 +/- 14.7 vs. 97.9 +/- 18.6, p < .05). Conclusion. Respiratory assessment in asthmatic children and adolescents with a history of pneumonia, especially recurrent pneumonia, often discloses symptoms needing corticosteroid therapy, and despite normal lung volumes and flows, mild reductions in the variables reflecting gas diffusion and atopic-airway inflammation (DLCO/VA and FENO). Whether these respiratory abnormalities persist in adulthood remains an open question