Chloride Incorporation Process in CH\u3csub\u3e3\u3c/sub\u3eNH\u3csub\u3e3\u3c/sub\u3ePbI\u3csub\u3e3-x\u3c/sub\u3eCl\u3csub\u3ex\u3c/sub\u3e Perovskites via Nanoscale Bandgap Maps

CH3NH3PbI3-xClx perovskites enable fabrication of highly efficient solar cells. Chloride ions benefit the morphology, carrier diffusion length and stability of perovskite films; however, whether those benefits stem from the presence of Cl− in the precursor solution or from their incorporation in annealed films is debated. In this work, the photothermal induced resonance (PTIR), an in situ technique with nanoscale resolution, is leveraged to measure the bandgap of CH3NH3PbI3-xClx films obtained by a multicycle coating process that produces high efficiency (≈16 %) solar cells. Because chloride ions modify the perovskite lattice, thereby widening the bandgap, measuring the bandgap locally yields the local chloride content. After a mild annealing (60 min, 60°C) the films consist of Cl-rich (x \u3c 0.3) and Cl-poor phases that, upon further annealing (110 °C), evolve into a homogenous Cl-poorer (x \u3c 0.06) phase, suggesting that methylammonium-chrloride is progressively expelled from the film. Despite the small chloride content, CH3NH3PbI3-xClx films show better thermal stability up to 140 °C with respect CH3NH3PbI3 films fabricated with the same methodology

Nanoscale mapping and spectroscopy of non-radiative hyperbolic modes in hexagonal boron nitride nanostructures

The inherent crystal anisotropy of hexagonal boron nitride (hBN) sustains naturally hyperbolic phonon polaritons, i.e. polaritons that can propagate with very large wavevectors within the material volume, thereby enabling optical confinement to exceedingly small dimensions. Indeed, previous research has shown that nanometer-scale truncated nanocone hBN cavities, with deep subwavelength dimensions, support three-dimensionally confined optical modes in the mid-infrared. Due to optical selection rules, only a few of many such modes predicted theoretically have been observed experimentally via far-field reflection and scattering-type scanning near-field optical microscopy. The Photothermal induced resonance (PTIR) technique probes optical and vibrational resonances overcoming weak far-field emission by leveraging an atomic force microscope (AFM) probe to transduce local sample expansion due to light absorption. Here we show that PTIR enables the direct observation of previously unobserved, dark hyperbolic modes of hBN nanostructures. Leveraging these optical modes could yield a new degree of control over the electromagnetic near-field concentration, polarization and angular momentum in nanophotonic applications.Comment: 14 pages with references, 4 figure

No evidence of SARS-CoV-2 in hospitalized patients with severe acute respiratory syndrome in five Italian hospitals from 1st November 2019 to 29th February 2020

Background On 9th January 2020, China CDC reported a novel coronavirus (later named SARS-CoV-2) as the causative agent of the coronavirus disease 2019 (COVID-19). Identifying the first appearance of virus is of epidemiological importance to tracking and mapping the spread of SARS-CoV-2 in a country. We therefore conducted a retrospective observational study to detect SARS-CoV-2 in oropharyngeal samples collected from hospitalized patients with a Severe Acute Respiratory Infection (SARI) enrolled in the DRIVE (Development of Robust and Innovative Vaccine Effectiveness) study in five Italian hospitals (CIRI-IT BIVE hospitals network) (1st November 2019 – 29th February 2020). Objectives To acquire new information on the real trend in SARS-CoV-2 infection during pandemic phase I and to determine the possible early appearance of the virus in Italy. Materials and methods Samples were tested for influenza [RT-PCR assay (A/H1N1, A/H3N2, B/Yam, B/Vic)] in accordance with the DRIVE study protocol. Subsequently, swabs underwent molecular testing for SARS-COV-2. [one-step real-time multiplex retro-transcription (RT) PCR]. Results In the 1683 samples collected, no evidence of SARS-CoV-2 was found. Moreover, 28.3% (477/1683) of swabs were positive for influenza viruses, the majority being type A (358 vs 119 type B). A/H3N2 was predominant among influenza A viruses (55%); among influenza B viruses, B/Victoria was prevalent. The highest influenza incidence rate was reported in patients aged 0–17 years (40.3%) followed by those aged 18–64 years (24.4%) and ≥65 years (14.8%). Conclusions In Italy, some studies have shown the early circulation of SARS-CoV-2 in northern regions, those most severely affected during phase I of the pandemic. In central and southern regions, by contrast no early circulation of the virus was registered. These results are in line with ours. These findings highlight the need to continue to carry out retrospective studies, in order to understand the epidemiology of the novel coronavirus, to better identify the clinical characteristics of COVID-19 in comparison with other acute respiratory illnesses (ARI), and to evaluate the real burden of COVID-19 on the healthcare system

Population-level benefits of increasing influenza vaccination uptake among Italian older adults: results from a granular panel model

BackgroundThe impact of seasonal influenza vaccination (SIV) on mortality is still controversial; some studies have claimed that increasing vaccination coverage rates is beneficial, while others have found no significant association. This study aimed to construct a granular longitudinal dataset of local VCRs and assess their effect on pneumonia- and influenza-related (P&I) mortality among Italian adults aged ≥ 65 years.MethodsNUTS-3 (nomenclature of territorial units for statistics) level data on SIV coverage were collected via a survey of local data holders. Fixed- and random-effects panel regression modeling, when adjusted for potential confounders, was performed to assess the association between local SIV coverage rates and P&I mortality in older adults.ResultsA total of 1,144 local VCRs from 2003 to 2019 were ascertained. In the fully adjusted fixed-effects model, each 1% increase in vaccination coverage was associated (P < 0.001) with a 0.6% (95% CI: 0.3–0.9%) average over-time decrease in P&I mortality. With an annual average of 9,293 P&I deaths in Italy, this model suggested that 56 deaths could have been avoided each year by increasing SIV coverage by 1%. The random-effects model produced similar results. The base-case results were robust in a sensitivity analysis.ConclusionOver the last two decades, Italian jurisdictions with higher SIV uptake had, on average, fewer P&I deaths among older adults. Local policy-makers should implement effective strategies to increase SIV coverage in the Italian senior population

SHARK-NIR: from K-band to a key instrument, a status update

SHARK-NIR channel is one of the two coronagraphic instruments proposed for the Large Binocular Telescope, in the framework of the call for second generation instruments, issued in 2014. Together with the SHARK-VIS channel, it will offer a few observing modes (direct imaging, coronagraphic imaging and coronagraphic low resolution spectroscopy) covering a wide wavelength domain, going from 0.5μm to 1.7μm. Initially proposed as an instrument covering also the K-band, the current design foresees a camera working from Y to H bands, exploiting in this way the synergy with other LBT instruments such as LBTI, which is actually covering wavelengths greater than L' band, and it will be soon upgraded to work also in K band. SHARK-NIR has been undergoing the conceptual design review at the end of 2015 and it has been approved to proceed to the final design phase, receiving the green light for successive construction and installation at LBT. The current design is significantly more flexible than the previous one, having an additional intermediate pupil plane that will allow the usage of coronagraphic techniques very efficient in term of contrast and vicinity to the star, increasing the instrument coronagraphic performance. The latter is necessary to properly exploit the search of giant exo-planets, which is the main science case and the driver for the technical choices of SHARK-NIR. We also emphasize that the LBT AO SOUL upgrade will further improve the AO performance, making possible to extend the exo-planet search to target fainter than normally achieved by other 8-m class telescopes, and opening in this way to other very interesting scientific scenarios, such as the characterization of AGN and Quasars (normally too faint to be observed) and increasing considerably the sample of disks and jets to be studied. Finally, we emphasize that SHARK-NIR will offer XAO direct imaging capability on a FoV of about 15"x15", and a simple coronagraphic spectroscopic mode offering spectral resolution ranging from few hundreds to few thousands. This article presents the current instrument design, together with the milestones for its installation at LBT. <P /

Berechnung von Zuverlaessigkeits- und Sicherheitskenngroessen der Hardware periodisch gepruefter einkanaliger Automatisierungseinrichtungen

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Nanostructured Lipid-Based Films for Substrate-Mediated Applications in Biotechnology

Amphiphilic in nature, lipids spontaneously self-assemble into a range of nanostructures in the presence of water. Among lipid self-assembled structures, liposomes and supported lipid bilayers have long held scientific interest for their main applications in drug delivery and plasma membrane models, respectively. In contrast, lipid-based multilayered membranes on solid supports only recently begin drawing scientists' attention. Current studies show that the stacking of multiple bilayers on a solid support yields cooperative structural and dynamic behavior that enables new functionalities. Lipid films provide compartmentalization, templating, and enhanced release of molecules of interest. Importantly, supported lipid phases exhibit long-range periodic nanoscale order and orientation that is tunable in response to a changing environment. Herein, the current understanding of lipid-based film research is summarized focusing on how unique structural characteristics enable the emergence of new applications including label-free biosensors, macroscale drug delivery, and substrate-mediated gene delivery. The authors' recent contributions focusing on the structural characterization of lipid-based films using small-angle X-ray scattering and atomic force microscopy are highlighted. In addition, new photothermally induced resonance and solid-state nuclear magnetic resonance data are described, providing insights into drug partition in lipid-based films as well as structure and dynamics at the molecular scale