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

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)

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

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

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

Perinatal Maternal Mental Health, Fetal Programming and Child Development

Maternal mental disorders over pregnancy show a clear influence on child development. This review is focused on the possible mechanisms by which maternal mental disorders influence fetal development via programming effects. This field is complex since mental health symptoms during pregnancy vary in type, timing and severity and maternal psychological distress is often accompanied by higher rates of smoking, alcohol use, poor diet and lifestyle. Studies are now beginning to examine fetal programming mechanisms, originally identified within the DOHaD framework, to examine how maternal mental disorders impact fetal development. Such mechanisms include hormonal priming effects such as elevated maternal glucocorticoids, alteration of placental function and perfusion, and epigenetic mechanisms. To date, mostly high prevalence mental disorders such as depression and anxiety have been investigated, but few studies employ diagnostic measures, and there is very little research examining the impact of maternal mental disorders such as schizophrenia, bipolar disorder, eating disorders and personality disorders on fetal development. The next wave of longitudinal studies need to focus on specific hypotheses driven by plausible biological mechanisms for fetal programming and follow children for a sufficient period in order to examine the early manifestations of developmental vulnerability. Intervention studies can then be targeted to altering these mechanisms of intergenerational transmission once identified