VUV-Vis optical characterization of Tetraphenyl-butadiene films on glass and specular reflector substrates from room to liquid Argon temperature

The use of efficient wavelength-shifters from the vacuum-ultraviolet to the photosensor's range of sensitivity is a key feature in detectors for Dark Matter search and neutrino physics based on liquid argon scintillation detection. Thin film of Tetraphenyl-butadiene (TPB) deposited onto the surface delimiting the active volume of the detector and/or onto the photosensor optical window is the most common solution in current and planned experiments. Detector design and response can be evaluated and correctly simulated only when the properties of the optical system in use (TPB film + substrate) are fully understood. Characterization of the optical system requires specific, sometimes sophisticated optical methodologies. In this paper the main features of TPB coatings on different, commonly used substrates is reported, as a result of two independent campaigns of measurements at the specialized optical metrology labs of ENEA and University of Tor Vergata. Measured features include TPB emission spectra with lineshape and relative intensity variation recorded as a function of the film thickness and for the first time down to LAr temperature, as well as optical reflectance and transmittance spectra of the TPB coated substrates in the wavelength range of the TPB emission

Modulation of microRNA editing, expression and processing by ADAR2 deaminase in glioblastoma.

Background: ADAR enzymes convert adenosines to inosines within double-stranded RNAs, including microRNA (miRNA) precursors, with important consequences on miRNA retargeting and expression. ADAR2 activity is impaired in glioblastoma and its rescue has anti-tumoral effects. However, how ADAR2 activity may impact the miRNome and the progression of glioblastoma is not known. Results: By integrating deep-sequencing and array approaches with bioinformatics analyses and molecular studies, we show that ADAR2 is essential to edit a small number of mature miRNAs and to significantly modulate the expression of about 90 miRNAs in glioblastoma cells. Specifically, the rescue of ADAR2 activity in cancer cells recovers the edited miRNA population lost in glioblastoma cell lines and tissues, and rebalances expression of onco-miRNAs and tumor suppressor miRNAs to the levels observed in normal human brain. We report that the major effect of ADAR2 is to reduce the expression of a large number of miRNAs, most of which act as onco-miRNAs. ADAR2 can edit miR-222/221 and miR-21 precursors and decrease the expression of the corresponding mature onco-miRNAs in vivo and in vitro, with important effects on cell proliferation and migration. Conclusions: Our findings disclose an additional layer of complexity in miRNome regulation and provide information to better understand the impact of ADAR2 editing enzyme in glioblastoma. We propose that ADAR2 is a key factor for maintaining edited-miRNA population and balancing the expression of several essential miRNAs involved in cancer

Fano collective resonance as complex mode in a two dimensional planar metasurface of plasmonic nanoparticles

Fano resonances are features in transmissivity/reflectivity/absorption that owe their origin to the interaction between a bright resonance and a dark (i.e., sub-radiant) narrower resonance, and may emerge in the optical properties of planar two-dimensional (2D) periodic arrays (metasurfaces) of plasmonic nanoparticles. In this Letter, we provide a thorough assessment of their nature for the general case of normal and oblique plane wave incidence, highlighting when a Fano resonance is affected by the mutual coupling in an array and its capability to support free modal solutions. We analyze the representative case of a metasurface of plasmonic nanoshells at ultraviolet frequencies and compute its absorption under TE- and TM-polarized, oblique plane-wave incidence. In particular, we find that plasmonic metasurfaces display two distinct types of resonances observable as absorption peaks: one is related to the Mie, dipolar resonance of each nanoparticle; the other is due to the forced excitation of free modes with small attenuation constant, usually found at oblique incidence. The latter is thus an array-induced collective Fano resonance. This realization opens up to manifold flexible designs at optical frequencies mixing individual and collective resonances. We explain the physical origin of such Fano resonances using the modal analysis, which allows to calculate the free modes with complex wavenumber supported by the metasurface. We define equivalent array dipolar polarizabilities that are directly related to the absorption physics at oblique incidence and show a direct dependence between array modal phase and attenuation constant and Fano resonances. We thus provide a more complete picture of Fano resonances that may lead to the design of filters, energy-harvesting devices, photodetectors, and sensors at ultraviolet frequencies.Comment: 6 pages, 5 figure

Adoption and Implementation of the Surgical Safety Checklist: Improving Safety in an Italian Teaching Hospital

Although it is known that clinical risk management tools such as the Surgical Checklist lead to greater safety for patients and protection for the operators, clinical risk management units have much work to do to implement and spread the use of quality health care tools

Versatile lithium fluoride thin-film solid-state detectors for nanoscale radiation imaging

Point defects in insulating materials are successfully used for radiation detectors. Among them, colour centres in lithium fluoride (LiF) are well known for application in dosimeters and in light-emitting devices and lasers. LiF thin-film detectors for extreme ultraviolet radiation, soft and hard X-rays, based on photoluminescence from aggregate electronic defects, are currently under development for imaging application with laboratory radiation sources, e.g. laser-driven plasma sources and conventional X-ray tubes, as well as large-scale facilities, e.g. synchrotrons and free-electron lasers. Among the peculiarities of these detectors, noteworthy ones are the very high intrinsic spatial resolution ( 1 cm2) and the wide dynamic range. Moreover, they are insensitive to ambient light and no development process is needed. The latent images stored in the LiF thin layer can be read with fluorescence optical microscopy techniques. These detectors prove to be highly versatile, as LiF is sensitive to almost any kind of radiation, including charged particles and neutrons, and can be grown in the form of polycrystalline thin films, whose photoluminescence response can be tailored trough the control of the growth conditions

Early lactation ratio of fat and protein percentage in milk is associated with health, milk production, and survival.

An observational study was conducted on 1,498 cows in 3 large Italian dairy farms. The objective of the study was to evaluate the prognostic value of early lactation fat-to-protein ratio in milk. In all 3 herds, an intensive herd health monitoring program was being practiced that included weekly visits and extensive data collection on health, reproduction, production, and culling. A milk sample was collected from all cows at approximately 7 d postpartum and the ratio of fat-to-protein percentage in this milk sample was measured. Animals with a fat-to-protein ratio in early lactation greater than 2.0 showed an increase in postpartum diseases such as retained placenta, left-displaced abomasums, metritis and clinical endometritis. We also observed a decrease in early lactation milk production but this was limited to cows in lactation 2 and higher when the fat-to-protein ratio was greater than 2.0 in the early postpartum milk sample. Finally, an increased risk of being culled from the herd was observed, with the risk of culling increasing with increasing fat-to-protein ratio in the early lactation milk sample. No effect of fat-to-protein ratio was found on the incidence of clinical mastitis in the 3 herds. From this study, we conclude that analyses of milk components in early postpartum (6-9 days in milk), particularly the ratio of fat-to-protein percentage, is a valuable indicator of lipo-mobilization and the negative energy balance status in postpartum cows. Because a single milk sample is sufficient to provide valuable information, we suggest that this is a valuable addition to herd health programs on dairy farms