227 research outputs found

    Large-scale seismic vulnerability and risk of masonry churches in seismic-prone areas: Two territorial case studies

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    In this paper, seismic vulnerability and risk assessment of two samples of churches, located in Teramo and Ischia island (Naples gulf), both affected by the most recent earthquakes that occurred in Italy, are presented. To this aim, we applied a simplified method particularly suitable for seismic evaluations at a territorial scale, providing a global resulting score to be compared among the cases analyzed. The data obtained allowed us to provide vulnerability maps and a seismic risk index for all the considered churches. In addition, the calculated indexes permit a preliminary health state evaluation of the inspected churches, for ranking the priorities and planning additional in-depth evaluations

    Behavior of N-Doped TiO2 and N-Doped ZnO in Photocatalytic Azo Dye Degradation under UV and Visible Light Irradiation: A Preliminary Investigation

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    Abstract: N-doped TiO2 (N-TiO2) and N-doped ZnO (N-ZnO) were synthesized utilizing ammonia as a dopant source. The chemico-physical characteristics of synthesized samples were studied by Raman spectroscopy, X-ray diffraction, SEM analysis, N2 adsorption–desorption at −196 ◦C, and diffuse reflectance spectroscopy. Compared to undoped samples, the introduction of nitrogen in the semiconductor lattice resulted in a shift of band-gap energy to a lower value: 3.0 eV for N-ZnO and 2.35 eV for N-TiO2. The photocatalysts were tested for the degradation of Eriochrome Black T (EBT), which was selected as a model azo dye. Both N-doped semiconductors evidenced an improvement in photocatalytic activity under visible light irradiation (62% and 20% EBT discoloration for N-TiO2 and N-ZnO, respectively) in comparison with the undoped samples, which were inactive in the presence of visible light. Different behavior was observed under UV irradiation. Whereas N-TiO2 was more photoactive than commercial undoped TiO2, the introduction of nitrogen in ZnO wurtzite resulted in a drastic reduction in photocatalytic activity, with only 45% EBT discoloration compared to total color removal obtained with the commercial ZnO sample, suggesting intrinsic limitations for doping of this class of semiconductors

    Novel high resolution detectors for Positron Emission Tomography (PET)

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    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

    Detector development for a novel Positron Emission Mammography scanner based on YAP:Ce crystals

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    A prototype for positron emission mammography is under development within a collaboration of the Departments of Physics of Pisa and Ferrara. The device will be composed of two opposing detectors (parallel plane geometry). The active part of the detector head is constituted by a matrix of scintillators with a small pixel size (2 2m m 2 ). We have evaluated the possibility to use an array of Position Sensitive PhotoMultiplier Tube (PSPMT mod R8520-C12 from Hamamatsu) for the readout of the scintillation matrix. Two different crystal-PMT coupling techniques have been explored: the results for each method are reported in this work. The overall performance, in terms of efficiency and pixel identification of the final prototype of the detector head are also presented. For future applications the new H8500 (also called the 'flat panel' PMT) has been studied and compared to the R8520 in terms of the imaging performance and other considerations such as cost and geometry. The imaging performance of these tubes is characterized in terms of the pixel image resolution and the peak-to-valley ratio. r 2004 Elsevier B.V. All rights reserved

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

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    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

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

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    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

    Intravitreal Brolucizumab for Pachychoroid Neovasculopathy Associated With Chronic Central Serous Chorioretinopathy

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    Purpose: To evaluate the anatomical and functional outcomes of intravitreal brolucizumab in eyes with chronic central serous chorioretinopathy complicated by pachychoroid neovasculopathy. Methods: Retrospective analysis of 34 eyes treated with intravitreal brolucizumab. Twenty-five eyes (73.5%) had been treated with other anti-vascular endothelial growth factor agents before switching to brolucizumab, whereas nine eyes were naïve. Outcome measures included the change of central foveal thickness and subfoveal choroidal thickness, evaluation of sub/intraretinal fluid on optical coherence tomography, and change in best-corrected visual acuity. Results: Before starting brolucizumab, 23 eyes showed subretinal fluid, 8 both subretinal and intraretinal fluid, and 3 intraretinal fluid only. At the last visit, 22 eyes (64.7%) showed complete reabsorption of both intraretinal and subretinal fluid, whereas subretinal fluid was still present in 8 eyes (23.5%), and both intraretinal and subretinal fluid in 4 eyes (11.8%). The mean number of brolucizumab injections required to achieve complete fluid reabsorption was 2.8 ± 1.8. central foveal thickness decreased from 317.8 ± 109.3 μm to 239.8 ± 74.8 μm (P = 0.0005) and subfoveal choroidal thickness decreased from 399.3 ± 86.2 μm to 355.5 ± 92.7 μm at the end of the follow-up period (P = 0.0008). The mean logarithm of the minimum angle of resolution best-corrected visual acuity improved from 0.4 ± 0.2 to 0.3 ± 0.2 at 1 month after the first injection and remained stable at the same values at the end of the follow-up period (P = 0.04). Conclusions: Intravitreal brolucizumab is effective for the treatment of naïve and recalcitrant pachychoroid neovasculopathy. Translational relevance: Intravitreal brolucizumab may represent an option in patients with pachychoroid neovasculopathy complicating chronic central serous chorioretinopathy

    Optical, morphological and photocatalytic properties of biobased tractable films of chitosan/donor-acceptor polymer blends

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    Biobased tractable films consisting of blends of chitosan (CS) with polymer bearing carbazole derivatives as pendant groups and fluorene-thiophene as donor-acceptor units (referred to as DA) were prepared, and their optical, morphological and photocatalytic properties were studied. DA was dissolved in tetrahydrofuran (THF) and mixed with an acidified aqueous solution containing chitosan to obtain chitosan/DA (CS/DA) films by solution casting. The fabricated biobased films were characterized using spectroscopic techniques (FT-IR and UV–vis), thermogravimetry, mechanical assays, contact angle analysis, and atomic force microscopy (AFM). The effects of varying DA compositions and the results of exposure to visible-light irradiation of the films were also analyzed. The results indicated the existence of interactions between chitosan and DA and a potentially profitable light-driven response of these biobased films. This behavior was reflected in the optical, topographical, and contact angle properties of the films, which exhibited different characteristics before and after visible-light exposure. Finally, the photocatalytic performance of the biobased films was tested via the decomposition of methyl orange (MO), as a reaction model system. Our results revealed a significant photocatalytic activity (according to biobased film composition, approximately 64 % and 87 % of methyl orange were degraded under continuous visible-light irradiation for 120 min) of the films which is attributed to the combined presence and synergetic effects of the film-forming ability of chitosan and the photoproperties of DA
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