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The COVID-19 pandemic has had a severe psychosocial impact on healthcare workers (HCWs). This systematic review and meta-analysis aimed at evaluating the association between individual features and depressive symptoms reported by HCWs during the pandemic. We searched Medline, Embase, and PsycInfo up to 23 June 2020. We included cross-sectional studies testing the association between individual correlates and depressive symptoms in HCWs during the SARS-CoV-2 outbreak. Fourteen studies met inclusion criteria, involving 14,173 HCWs (3,070 with depressive symptoms). Women (OR = 1.50; 95 %CI: 1.28–1.76; I2 = 40.0 %), individuals with suspected/confirmed COVID-19 (OR = 2.10; 95 %CI: 1.64–2.69; I2 = 0 %), and those with an infected family member or friend (OR = 1.67; 95 %CI: 1.37–2.04; I2 = 0%) were more likely to report depressive features, which, instead, were less frequent among doctors (compared with nurses) (OR = 0.80; 95 %CI: 0.66–0.98; I2 = 48.2 %) and HCWs who felt adequately protected (OR = 0.48; 95 %CI: 0.32–0.72; I2 = 36.3 %). Our study provided timely evidence on the correlates of depressive symptoms among HCWs during the pandemic. Early screening is crucial to develop tailored health interventions, redesigning the response to COVID-19.

The carrier trapping and recombination mechanisms occurring in Ce-doped silica fibers, produced by a sol–gel technique, are investigated by combining temperature-dependent steady-state X-ray-excited luminescence, wavelength- and time-resolved scintillation measurements, and wavelength-resolved thermally stimulated luminescence, focusing especially on the temperature range from 10 to 320 K. The scintillation decay features a decay time of the order of tens of nanoseconds, characteristic of the parity- and spin-allowed 5d–4f radiative transition of Ce3+ ions. In addition, a slow and complex decay contribution in the microsecond timescale is detected. We interpret these features as due to the radiative recombination at Ce centers of carriers freed from a continuous distribution of trapping sites in the forbidden gap as well as to the occurrence of an athermal tunneling recombination process between traps and Ce3+ ions. This interpretation is reinforced by good agreement between independent evaluations of trap depths and lifetimes obtained by both the numerical analysis of scintillation time decays and thermally stimulated luminescence experiments.

Rare-earth doped sol-gel glasses were proven to be suitable materials for scintillating optical fiber sensors, to be employed in real-time medical dosimetry. To exploit the high granularity and flexibility of calorimeters made of fibers, their use as the active scintillating material in a sampling electromagnetic Spaghetti Calorimeter (SpaCal) or as the scintillating component in a dual-readout calorimeter, coupled with undoped fibers acting as Cherenkov radiators, has also been recently proposed. Besides crystalline fibers, active research on silica fibers is also being carried on. An extremely good radiation hardness is a crucial property for high-energy physics applications: previous results of irradiation tests on Ce-doped silica fibers with X- and gamma -rays up to 10 kGy pointed out the formation of radiation-induced defects, however an improvement of radiation resistance by reducing Ce content inside the fiber core was achieved, paving the way for further material development. Here we present an in depth characterization of Ce-doped sol-gel silica fibers under GeV electron beam exposure: silica fibers were tested in a SpaCal prototype and the analysis of their response suggests the possibility of a dual readout of Cherenkov and scintillation light simultaneously with the same doped silica fiber. An event by event pulse shape-based discrimination of Cherenkov and scintillation signals permits a separate study of linearity as a function of energy and attenuation length, taking advantage of the double side readout technique. The investigation of various mechanisms of interaction between radiation and sol-gel silica fibers as well as of their scintillation properties represents the goal of this work. An accurate comparison with their photoluminescence and radioluminescence response has been carried out, in order to optimize silica fibers performances as both scintillators and Cherenkov radiators.

Binary alkali-earth silicate glasses doped with Ce3+, Tb3+, and Dy3+were obtained by melt-quenching technique and their photo- and radio-luminescence properties were investigated. The disordered structure of the glass is responsible for an inhomogeneous broadening of the electronic radiative 5d1energy level of Ce3+due to their localization in several positions with different surroundings, possessing a slightly different local ligand field. The influence of glass matrix composition on the Stokes shift as a function of ionic radius of the cation was shown. The radio-luminescence spectral shapes were related to the simultaneous occurrence of emissions from all Ce3+configurations with relative weights proportional to their abundance in the glasses. The possibility of excitation of Ce3+in different localizations was demonstrated and confirmed by the systematic shift of emission from excitation. On the contrary, no shift was observed in the Tb3+and Dy3+doped glasses, thanks to the lower effect of ligand field on their radiative electronic levels

Water-based liquid scintillators (WbLS) present an attractive target medium for large-scale detectors with the ability to enhance the separation of Cherenkov and scintillation signals from a single target. This work characterizes the scintillation properties of WbLS samples based on LAB/PPO liquid scintillator (LS). X-ray luminescence spectra, decay profiles, and relative light yields are measured for WbLS of varying LS concentration as well as for pure LS with a range of PPO concentrations up to 90 g L-1. The scintillation properties of the WbLS are related to the precursor LAB/PPO: starting from 90 g L-1PPO in LAB before synthesis, the resulting WbLS have spectroscopic properties that instead match 10 g L-1 PPO in LAB. This could indicate that the concentration of active PPO in the WbLS samples depends on their processing.

The recent trends in scintillator technologies stimulate research efforts toward the development of novel materials morphologies, such as nanoparticles, able to efficiently convert ionizing radiations into light. For example, scintillating nanoparticles attract great interest in medical oncological therapies. In this work, the structural and morphological properties of HfO2:Ti nanoparticles with Ti concentrations from 0.03 to 10 mol% and subjected to calcination up to 1000 °C are thoroughly characterized; moreover, X-ray photoelectron spectroscopy reveals the incorporation of Ti in both Ti (III) and Ti (IV) chemical states in as prepared samples, while the exclusive presence of Ti(IV) is unambiguously identified in calcined nanoparticles. The optical emission under X-ray excitation evidences an intense Ti (IV)-related luminescence at 2.5 eV in high temperature calcined samples with a few microseconds scintillation lifetime, and efficiency comparable to that of Bi4Ge3O12 reference scintillator. Finally, the competitive role of defects in charge carriers capture is demonstrated by the monotonic increase of the 2.5 eV band during prolonged X-ray irradiation, more evident for nanoparticles with titanium concentration below 1 mol%. HfO2:Ti may also find application in X-ray triggered oncological therapies by using the Ti (IV)-related bright radioluminescence to excite photosensitizer molecules for singlet oxygen generation.

We establish the possibility of Landau damping for gravitational scalar waves which propagate in a non-collisional gas of particles. In particular, under the hypothesis of homogeneity and isotropy, we describe the medium at the equilibrium with a Jüttner–Maxwell distribution, and we analytically determine the damping rate from the Vlasov equation. We find that damping occurs only if the phase velocity of the wave is subluminal throughout the propagation within the medium. Finally, we investigate relativistic media in cosmological settings by adopting numerical techniques.

Aim: To develop an instrument to investigate knowledge and predictive factors of needlestick and sharps injuries (NSIs) in nursing students during clinical placements. Design: Instrument development and cross-sectional study for psychometric testing. Methods: A self-administered instrument including demographic data, injury epidemiology and predictive factors of NSIs was developed between October 2018–January 2019. Content validity was assessed by a panel of experts. The instrument's factor structure and discriminant validity were explored using principal components analysis. The STROBE guidelines were followed. Results: Evidence of content validity was found (S-CVI 0.75; I-CVI 0.50–1.00). A three-factor structure was shown by exploratory factor analysis. Of the 238 participants, 39% had been injured at least once, of which 67.3% in the second year. Higher perceptions of “personal exposure” (4.06, SD 3.78) were reported by third-year students. Higher scores for “perceived benefits” of preventive behaviours (13.6, SD 1.46) were reported by second-year students.

Single crystals of PbMoO4 were studied by means of light-induced electron paramagnetic resonance (EPR) and wavelength resolved thermally stimulated luminescence (TSL). The work is focused on the electron self-trapped at the (MoO4)2- complex. Detailed analysis of the EPR spectra of this complex allowed to determine a set of spin-Hamiltonian parameters including g factor and the 95,97Mo, 207Pb hyperfine tensors further used in calculations performed in terms of crystal field and LCAO-MO theories. They have shown a significant overlap of the Mo 5d1 and 6s6p ligand lead orbitals. The contributions of oxygen and lead to the molecular orbitals with an electron trapped at the (MoO4)3- complex were about 14% and 38%, respectively. The decay of the molybdenum center EPR intensity with annealing temperature provided information about thermal stability of the center, which thermally destroys already at 40 K. Trap depth and frequency factor, Et = 0.05 eV, and f0 = 104 s−1, have been determined. The TSL glow curve displays two overlapping peaks in the 40–50 K temperature region, corresponding to the disappearance of the EPR signal from the (MoO4)3- center. By partial cleaning technique and initial rise method it is shown that the lower temperature peak is related to a trap with thermal parameters similar to those determined for the (MoO4)3- center. This allows to correlate it to the thermal destruction of the (MoO4)3- center. The obtained results are discussed in a broader frame of charge trapping mechanism in all the family of tungstate and molybdate-based single crystals.

In recent years, oxide materials based on garnet structure are being investigated as very promising candidates in the field of scintillation because of their high density, good chemical stability, optical transparency, and the possibility to easily incorporate luminescent rare-earth ions. Several studies demonstrated that garnet crystals show high light yield and advantageous timing performances, which make them of interest for applications in medical imaging and high energy physics detectors [1]. Among synthetic garnets, Ce-doped gadolinium gallium aluminum garnet (GGAG:Ce) is a relatively new and interesting material. It is a mixed garnet that has displayed very good scintillation and luminescence properties: its high density enhances the interaction with ionizing radiation, and the presence of Gd provides a high cross section for thermal neutron capture [2]. GGAG:Ce preserves a crystalline cubic structure, which allows to produce it in the form of transparent polycrystalline ceramic [3] with favorable characteristics for optical applications such as lasers, LEDs, and scintillators. In this work, ceramic samples were produced by reaction sintering from commercial oxide powders: the mixed powders were pressed into pellets and sintered by a combined process of air sintering and hot isostatic pressing. The sintering process was carefully selected and the use of sintering additives was optimized to eliminate porosity, which is crucial to achieve a good optical transparency. Optical properties were studied by means of optical absorption spectroscopy, steady-state and time resolved photo- and radio- luminescence, and correlated to the fabrication process parameters. Moreover, trapping phenomena caused by the presence of point defects were investigated by wavelength resolved thermally stimulated luminescence in a wide temperature range (10 – 800 K); a significant persistent luminescence signal was also singled out and investigated as a function of temperature. The presen