106 research outputs found
Ophthalmological emergencies and the SARSCoV-2 outbreak
Since the end of 2019, an outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), originating in the Chinese city of Wuhan has spread rapidly worldwide causing thousands of deaths. Coronavirus disease (COVID-19) is supported by SARS-CoV-2 and represents the causative agent of a potentially fatal disease that is of great global public health concern. Italy has been the first European country recording an elevated number of infected forcing the Italian Government to call for total lockdown. The lockdown had the aim to limit the spread of infection through social distancing. The purpose of this study is to analyze how the pandemic has affected the patient’s accesses to the Ophthalmological Emergency Department of a tertiary referral center in central-northern Italy, during the lockdown period. The charts of all patients that came to the Emergency Department during the lockdown period (March 10 –May 4, 2020) have been retrospectively collected and compared with those in the same period of 2019 and the period from 15 January– 9 March 2020. A significant reduction of visits during the lockdown has been observed, compared with those of pre-lockdown period (reduction of 65.4%) and with those of the same period of 2019 (reduction of 74.3%). Particularly, during the lockdown, minor and not urgency visits decreased whereas the undeferrable urgency ones increased. These pieces of evidence could be explained by the fear of patients to be infected; but also revealed patients misuse of emergency services
Comparison of techniques for computing shell-model effective operators
Different techniques for calculating effective operators within the framework
of the shell model using the same effective interaction and the same excitation
spaces are presented. Starting with the large-basis no-core approach, we
compare the time-honored perturbation-expansion approach and a model-space
truncation approach. Results for the electric quadrupole and magnetic dipole
operators are presented for Li. The convergence trends and dependence of
the effective operators on differing excitation spaces and Pauli Q-operators is
studied. In addition, the dependence of the electric-quadrupole effective
charge on the harmonic-oscillator frequency and the mass number, for A=5,6, is
investigated in the model-space truncation approach.Comment: 18 pages. REVTEX. 4 PostScript figure
Photoluminescence Emission Induced by Localized States in Halide Passivated Colloidal Two-Dimensional WS2 Nanoflakes
Engineering physicochemical properties of two-dimensional transition metal dichalcogenide (2D-TMD) materials by surface
manipulation is essential for their practical and large-scale application especially for colloidal 2D-TMDs that are plagued by the unintentional
formation of structural defects during the synthetic procedure. However, the available methods to manage surface states of 2D-TMDs in solution-phase are still limited hampering the production of high quality colloidal 2D-TMD inks to be straightforwardly assembled into actual devices. Here, we demonstrate an efficient solution-phase strategy to passivate surface defect states of colloidally synthetized WS2 nanoflakes with halide ligands, resulting in the activation of the photoluminescence emission. Photophysical investigation and density functional theory calculations suggest that halide atoms enable the suppression of non-radiative recombination through the elimination deep gap trap states, and introduce localized states in the energy band structure from which excitons efficiently recombine. Halide passivated WS2 nanoflakes importantly
preserve colloidal stability and photoluminescence emission after several weeks of storing in ambient atmosphere, corroborating the potential of our developed 2D-TMD inks
Transition Rates between Mixed Symmetry States: First Measurement in 94Mo
The nucleus 94Mo was investigated using a powerful combination of
gamma-singles photon scattering experiments and gamma-gamma-coincidence studies
following the beta-decay of 94mTc. The data survey short-lived J^pi=1+,2+
states and include branching ratios, E2/M1 mixing ratios, lifetimes, and
transition strengths. The mixed-symmetry (MS) 1+ scissors mode and the 2+ MS
state are identified from M1 strengths. A gamma transition between MS states
was observed and its rate was measured. Nine M1 and E2 strengths involving MS
states agree with the O(6) limit of the interacting boson model-2 using the
proton boson E2 charge as the only free parameter.Comment: 9 pages, 3 PostScript figures included, ReVTeX, accepted for
publication in Physical Review Letters, tentatively scheduled for August 9,
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Sugar-and-acid profile of Penjar tomatoes and its evolution during storage
The alcobaca mutation in the Penjar tomato (Solanum lycopersicum L.) variety alters the ripening process and confers a long shelf life (more than four months). Storage of Penjar tomatoes leads to a distinctive sensory profile valued by local consumers, who prefer aged tomatoes to fresh ones. To study chemical changes occurring during storage, we characterized the complete sugar-and-acid profile of 25 accessions at harvest and at 2 and 4 months after harvest. We found considerable variability in the sugar-and-acid profile within the Penjar variety, especially for fructose and glucose. Some accessions presented exceptionally high values for sugars, making them especially interesting for breeding programs. During postharvest, the concentration of glucose, fructose, and citric acid decreased, whereas the concentration of malic and glutamic acids increased. Data from this study offer novel insights into postharvest changes in tomato quality parameters and help elucidate the reasons for the appreciation of this variety by consumers.Postprint (published version
Crystallinity Effects in Sequentially Processed and Blend-Cast Bulk-Heterojunction Polymer/Fullerene Photovoltaics
Although most polymer/fullerene-based solar cells are cast from a blend of the components in solution, it is also possible to sequentially process the polymer and fullerene layers from quasi-orthogonal solvents. Sequential processing (SqP) not only produces photovoltaic devices with efficiencies comparable to the more traditional bulk heterojunction (BHJ) solar cells produced by blend casting (BC) but also offers the advantage that the polymer and fullerene layers can be optimized separately. In this paper, we explore the morphology produced when sequentially processing polymer/fullerene solar cells and compare it to the BC morphology. We find that increasing polymer regioregularity leads to the opposite effect in SqP and BC BHJ solar cells. We start by constructing a series of SqP and BC solar cells using different types of poly(3-hexylthiophene) (P3HT) that vary in regioregulary and polydispersity combined with [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM). We use grazing incidence wide-angle X-ray scattering to demonstrate how strongly changes in the P3HT and PCBM crystallinity upon thermal annealing of SqP and BC BHJ films depend on polymer regioregularity. For SqP devices, low regioregularity P3HT films that possess more amorphous regions allow for more PCBM crystallite growth and thus show better photovoltaic device efficiency. On the other hand, highly regioregular P3HT leads to a more favorable morphology and better device efficiency for BC BHJ films. Comparing the photovoltaic performance and structural characterization indicates that the mechanisms controlling morphology in the active layers are fundamentally different for BHJs formed via SqP and BC. Most importantly, we find that nanoscale morphology in both SqP and BC BHJs can be systematically controlled by tuning the amorphous fraction of polymer in the active layer. © 2014 American Chemical Society
Tre Giorni d'Architettura. Ciclo di incontri sul tema dell'abitare
La 3GA – Tre giorni di Architettura ad Altamura è un esperimento culturale nato in maniera
proactive dall’iniziativa di tre giovani altamurani, studenti di architettura presso l’universitĂ
La Sapienza di Roma, che decidono di mettersi in gioco e di organizzare un ciclo di incontri
pubblici sul tema dell’abitare con l’intento di animare un fermento culturale sopito,
promuovendo pratiche di cittadinanza attiva e incentivando la partecipazione dei cittadini
nei processi di trasformazione della cittĂ .
Se si intende l’architettura come strumento fondamentale dell’uomo per abitare la terra,
risulta spontaneo chiedersi come mai non ci siano occasioni nel territorio altamurano
per promuovere una cultura architettonica autorevole in grado di contrastare il dilagare
dell’edilizia troppo spesso priva di qualità e fuori dalle regole.
Il mondo dell’architettura è spesso visto come un ambito chiuso, accessibile e comprensibile
solo per gli addetti ai lavori. A tal proposito la 3GA riunisce i principali soggetti del processo
progettuale (pubblica amministrazione, professionisti e imprese, universitĂ e studenti),
costituendosi come un’importante momento di dibattito e confronto sulle principali
questioni relative al territorio e alla cittĂ . Si intende sensibilizzare i cittadini, riportando
alla coscienza collettiva il tema sempre attuale dell’abitare, e ridurre le evidenti distanze
esistenti tra il mondo universitario e quello professionale, offrendo la possibilitĂ a studenti
e giovani professionisti locali di confrontarsi, raccontando le proprie esperienze. In ultima
analisi l’operazione crea i presupposti per un network di relazioni in grado di generare
opportunitĂ in chiave formativa e professionale per i giovani.
Il ciclo di incontri si è tenuto ad Altamura nelle giornate 3, 4 e 5 Agosto 2011 presso l’aula
magna del Liceo Classico “Luca de Samuele Cagnazzi”
AlphaScope vs lens-based hysteroscope for office polypectomy without anesthesia: randomized controlled study.
In this randomized controlled study, effectiveness, operative time, and acceptability of endometrial polypectomy were compared using an AlphaScope vs an office operative lens-based hysteroscope (LBH). One hundred fifty women with a diagnosis of endometrial polyp were operated on using an AlphaScope or LBH in the office setting. In 73 procedures using the AlphaScope (97.3%) and 68 using the LBH (90.7%), the polyp was successfully removed completely. In the AlphaScope group, 2 procedures were incomplete because of excessive endometrial mucosa thickness. In the LBH group, 3 procedures were incomplete because of difficulty in management of a large polyp, and 4 procedures were stopped because of patient pain and low compliance. Time to completion of the procedure and complete removal of the polyp was significantly shorter in the AlphaScope group than in the LBH group (p < .05). Similarly, the pain score at the end of the procedure was significantly lower in the AlphaScope group than in the LBH group (p < .05). The AlphaScope is an effective operative hysteroscope that increases the possibility of performing endometrial polypectomy in the office setting without anesthesia and improves the indications for and acceptability of office hysteroscopy
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