Novel high resolution detectors for Positron Emission Tomography (PET)

Abstract In this paper we present some recent results we have obtained in the development of detectors for small animal PET and for PEM, based on the use of Position Sensitive PMTS or Hybrid Photo Diodes (HPDs) coupled to crystal matrices. New ideas and future developments are discussed

Toxicological Findings of Self-Poisoning Suicidal Deaths: A Systematic Review by Countries

The use of illicit and non-illicit substances is widespread in suicides. The toxicological data may help in understanding the mechanism of death. This systematic review aimed to analyze autopsies related to suicides by consuming poison, focusing on the correlation between substance use and the country of origin to create an alarm bell to indicate that suicide maybe attempted and prevent it. The systematic review was conducted according to the PRISMA guidelines, with the primary objective of identifying autopsies conducted in cases of suicide by consuming poison in specific geographic areas. Significant differences in substances were observed between low-income and Western countries that confirm previous literature data. In rural areas and Asian countries, most suicides by consuming poison involve the use of pesticides, such as organophosphates and carbamates. In Western countries, illicit drugs and medically prescribed drugs are the leading cause of suicide by self-poisoning. Future research should shed light on the correlation between social, medical, and demographic characteristics and the autopsy findings in suicides by self-poisoning to highlight the risk factors and implement tailored prevention programs worldwide. Performing a complete autopsy on a suspected suicide by self-poisoning could be essential in supporting worldwide public health measures and policy makers. Therefore, complete autopsies in such cases must be vigorously promoted

Antimicrobial Effectiveness of Innovative Photocatalysts: A Review

Waterborne pathogens represent one of the most widespread environmental concerns. Conventional disinfection methods, including chlorination and UV, pose several operational and environmental problems; namely, formation of potentially hazardous disinfection by-products (DBPs) and high energy consumption. Therefore, there is high demand for effective, low-cost disinfection treatments. Among advanced oxidation processes, the photocatalytic process, a form of green technology, is becoming increasingly attractive. A systematic review was carried out on the synthesis, characterization, toxicity, and antimicrobial performance of innovative engineered photocatalysts. In recent decades, various engineered photocatalysts have been developed to overcome the limits of conventional photocatalysts using different synthesis methods, and these are discussed together with the main parameters influencing the process behaviors. The potential environmental risks of engineered photocatalysts are also addressed, considering the toxicity effects presented in the literature

Label-free fiber optic optrode for the detection of class C beta-lactamases expressed by drug resistant bacteria

This paper reports the experimental assessment of an automated optical assay based on label free optical fiber optrodes for the fast detection of class C beta-lactamases (AmpC BLs), actually considered as one of the most important sources of resistance to beta-lactams antibiotics expressed by resistant bacteria. Reflection-type long period fiber gratings (RT-LPG) have been used as highly sensitive label free optrodes, while a higher affine boronic acid based ligand was here selected to enhance the overall assay performances compared to those obtained in our first demonstration. In order to prove the feasibility analysis towards a fully automated optical assay, an engineered system was developed to simultaneously manipulate and interrogate multiple fiber optic optrodes in the different phases of the assay. The automated system tested in AmpC solutions at increasing concentrations demonstrated a limit of detection (LOD) of 6 nM, three times better when compared with the results obtained in our previous work. Moreover, the real effectiveness of the proposed optical assay has been also confirmed in complex matrices as the case of lysates of Escherichia coli overexpressing AmpC. (C) 2017 Optical Society of Americ

Photocatalytic removal of methyl orange azo dye with simultaneous hydrogen production using ru-modified zno photocatalyst

The aim of this work is to demonstrate the effectiveness of the photocatalytic process in the Methyl Orange azo dye degradation and simultaneous H2 production by using ZnO doped with ruthenium. Ru-modified ZnO photocatalysts were prepared by precipitation method and were characterized by different techniques (XRF, Raman, XRD, N2 adsorption at −196 °C, and UV–vis DRS). The experiments were carried out in a pyrex cylindrical reactor equipped with a nitrogen distributor device and irradiated by four UV lamps with the main wavelength emission at 365 nm. Different Ru amounts (from 0.10 to 0.50 mol%) were tested in order to establish the optimal amount of the metal to be used for the ZnO doping. The photocatalytic activity was evaluated both in terms of Methyl Orange removal and hydrogen production. The experimental results showed that the best activity, both in terms of H2 production and Methyl Orange degradation, was obtained with the Ru-modified ZnO photocatalyst at 0.25 mol% Ru loading. In particular, after four hours of UV irradiation time, the discoloration and mineralization degree were equal to 83% and 78%, with a simultaneous hydrogen production of 1216 µmol L−1. This result demonstrates the ability of the photocatalytic process to valorize a dye present in wastewater, managing to obtain a hydrogen production comparable with the data present in the literature today in the presence of other sacrificial substances

Combined Energy-Seismic Retrofit of Existing Historical Masonry Buildings: The Novel “DUO System” Coating System Applied to a Case Study

The safety of the built heritage of our cities towards environmental factors and seismic actions is a pressing need for designers and researchers. The actual trend is to setup effective solutions to reduce thermal dispersions through the building envelope. Contrarily, combined systems able to enhance the resistance of constructions to earthquakes, on the one hand, and, on the other hand, to increase the energetic efficiency of existing buildings are scarcely diffused on the market and are rarely investigated in the scientific literature. In this framework, the seismic design of the new envelope DUO system for seismic-environmental requalification of existing masonry constructions is illustrated in the present paper with reference to a case study in the Neapolitan area. After the geometrical and mechanical characterization of the investigated building is performed, an FEM model of the masonry construction is setup by the SAP2000 analysis program, which has allowed performing pushover analyses. Based on the non-linear seismic response of the construction, an appropriate upgrading design mainly based on the innovative seismic envelope DUO system has been made. The static non-linear analyses applied to the upgraded FEM model of the building have shown a clear increase in performance in terms of strength, stiffness and ductility, thus confirming the effectiveness of the proposed envelope system

Comparative analysis among different analysis programs for seismic vulnerability evaluation of a masonry building compound in the District of Naples

Masonry building compounds are sets of structural units having at least one common wall. The numerical analysis of the structural units grouped in aggregate, which are very diffused in Italian historical centres, is needed for identifying the structural interactions among them. Starting from these premises, in the current paper a masonry building aggregate built in the early twentieth century in the municipality of Cercola (district of Naples, Italy) and made of four structural units has been investigated as a case study. The structural behaviour under seismic forces has been investigated through non-linear static analyses. In particular, both the whole aggregate and the individual structural units have been modelled. Moreover, the single structural units have been considered both in the grouped and isolated conditions in order to assess either the beneficial or detrimental effect of the aggregated condition. The numerical models have been carried out with three different FEM software, namely 3MURI, CDS Win and Edilus, which schematise masonry buildings in different way. The analysis purpose has been to highlight the different results obtained with the three programs and to assess the most reliable seismic behaviour of investigated structural units. Finally, the susceptibility at damage of the case study aggregate has been evaluated through empirical fragility curves and mechanical vulnerability curves, which have been compared to each other and can be considered as preliminary tools to setup effective rehabilitation interventions

Visible light driven photocatalytic hydrogen evolution using different sacrificial reagents

In this work the photocatalytic hydrogen production from aqueous solution containing organic compounds, using perovskite based photocatalyst supported on magnetic particles, was studied. In particular a photocatalyst based on Ru doped LaFeO3 was used. The photocatalyst was prepared by solution combustion synthesis using citric acid as organic fuel, and it was characterized by different techniques, such as XRD, UV-Vis DRS and Raman spectroscopy. This semiconductor has shown photocatalytic activity in presence of visible light and it was supported on Fe2O3 magnetic particles in order to remove it easily at the end of the process. The Fe2O3 particles were prepared by combustion flame synthesis, using citric acid as organic fuel and metal nitrate as iron oxide precursor. The Ru-LaFeO3 photocatalyst was coupled with magnetic Fe2O3 particles by a physical mixture in order to ensure a tight contact between the two solid phases (Ru-LaFeO3/Fe2O3). Photocatalytic tests were carried out in a pyrex cylindrical reactor equipped with a N2 distributor device and irradiated by visible-LEDs. Different aqueous solution containing organic compounds such as ethanol, glycerol or methanol were tested. The experimental results evidenced that the higher hydrogen production (about 10000 μmol L-1 after 4 h of irradiation time) was obtained in presence of methanol. The magnetic composite showed a very high stability also after several reuse cycles