22 research outputs found

    Effect of the embedment of carbon doped nanocomposites in a real matrix on the enhanced photocatalytic activity

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    Solar light can be used by semiconductor nanocrystals as a free and largely available source of energy to transform air pollutants into non-volatile less harmful chemicals. The efficiency of this process can be enhanced by doping the semiconductor with carbon-based materials, such as graphene. Nevertheless, such an increased activity has been reported (i) for nanocomposite photocatalysts produced on the research laboratory scale, (ii) analyzing their performance as self-standing photocatalysts and not after incorporation into “real” matrixes (e.g. building materials) and (iii) typically using model target pollutants instead of “real” hazardous ones. Here we describe the large-scale preparation of two series of carbon based photocatalysts starting from commercial materials and we demonstrate their superior photocatalytic activity in degrading important air pollutants as nitrogen oxides, compared to undoped photocatalysts. The photocatalytic activity was evaluated by NOx abatement adopting the continuous flow procedure and the apparatus reported in the Italian standard UNI 11,247. Best performing materials were incorporated into two different inorganic matrixes (cement and lime). In both cases, the superior photocatalytic performances were maintained. An improvement up to 42±7% of the photocatalytic activity was measured in the case of a cement sample for a carbon-doped photocatalyst with respect to bare TiO2 . The materials were characterized by UV-Vis spectroscopy, high resolution powder X-ray diffraction (HR-PXRD), high-resolution scanning electron microscopy (HR-SEM) energy-dispersive X-ray spectroscopy (EDS) and micro-Raman

    Photocatalytic activity of exfoliated graphite-TiO2_2 nanocomposites

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    We investigate the photocatalytic performance of composites prepared in a one-step process by liquid-phase exfoliation of graphite in the presence of TiO2 nanoparticles (NPs) at atmospheric pressure and in water, without heating or adding any surfactant, and starting from low-cost commercial reagents. These show enhanced photocatalytic activity, degrading up to 40% more pollutants with respect to the starting TiO2-NPs, in the case of a model dye target, and up to 70% more pollutants in the case of nitrogen oxides. In order to understand the photo-physical mechanisms underlying this enhancement, we investigate the photo-generation of reactive species (trapped holes and electrons) by ultrafast transient absorption spectroscopy. We observe an electron transfer process from TiO2 to the graphite flakes within the first picoseconds of the relaxation dynamics, which causes the decrease of the charge recombination rate, and increases the efficiency of the reactive species photo-production.We acknowledge funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 785219 (GrapheneCore2), EU Neurofibres, ERC Minegrace and Hetero2D, EPSRC Grants EP/509K01711X/1, EP/K017144/1, EP/N010345/1, EP/M507799/5101, and EP/L016087/1

    Quali strumenti giuridici statali e regionali per le comunit\ue0 patrimoniali?

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    The Framework Convention on the Value of Cultural Heritage for Society (Faro Convention, 2005) recognizes a central role to heritage communities in the process of identification, study, interpretation, protection, conservation and presentation of the cultural heritage. As a signatory State of the Convention (signed on 27th February 2013, still waiting for ratification), Italy has in any case to ensure its contribution to the safeguarding of the tangible and intangible cultural heritage by adequate policies. Currently, a State law providing a general regulation of the participation of civil society to the protection and the enhancement of cultural heritage in the Italian legal system has not been adopted yet. Nevertheless, communities, groups and individuals have a wide range of instruments available, which can be drawn by an accurate interpretation of the Constitution and of many State and regional laws. In the long run, the persistent lack of common rules on this subject may be a source of uncertainty, capable of weakening, instead of strengthening, the role of heritage communities, in contrast with the principles of the Faro Convention

    Citizens of Europe

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    Il titolo della collana esprime la volont\ue0 di approfondire i profili legati al processo di integrazione europeo, non ignorandone i risvolti pi\uf9 discutibili e burocratici ma sapendo guardare al di l\ue0 di essi, nella logica che traspare dal gioco di assonanze indicato dal titolo. In questo terzo volume Citizens of Europe, dedicato ai temi delle identit\ue0 e della cittadinanza culturale, viene in rilievo la tensione tra i limiti delle politiche, culturali e di cittadinanza, perseguite dalla UE e l\u2019imporsi progressivo \u2013 malgrado le cupe ombre proiettate dalla drammatica attualit\ue0 \u2013 di una pi\uf9 ampia nozione di \u2018cittadinanza d\u2019Europa\u2019, scandita in particolare da quei recenti strumenti giuridici del Consiglio d\u2019Europa attraverso i quali l\u2019afflato europeo, non imprigionato nelle pastoie dei meccanismi della EU citizenship, si sviluppa pi\uf9 significativamente

    Efficacy and safety of reparixin in patients with severe covid-19 Pneumonia. A phase 3, randomized, double-blind placebo-controlled study

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    Introduction: Polymorphonuclear cell influx into the interstitial and bronchoalveolar spaces is a cardinal feature of severe coronavirus disease 2019 (COVID-19), principally mediated by interleukin-8 (IL-8). We sought to determine whether reparixin, a novel IL-8 pathway inhibitor, could reduce disease progression in patients hospitalized with severe COVID-19 pneumonia. Methods: In this Phase 3, randomized, double-blind, placebo-controlled, multicenter study, hospitalized adult patients with severe COVID-19 pneumonia were randomized 2:1 to receive oral reparixin 1200 mg three times daily or placebo for up to 21 days or until hospital discharge. The primary endpoint was the proportion of patients alive and free of respiratory failure at Day 28, with key secondary endpoints being the proportion of patients free of respiratory failure at Day 60, incidence of intensive care unit (ICU) admission by Day 28 and time to recovery by Day 28. Results: Of 279 patients randomized, 182 received at least one dose of reparixin and 88 received placebo. The proportion of patients alive and free of respiratory failure at Day 28 was similar in the two groups {83.5% versus 80.7%; odds ratio 1.63 [95% confidence interval (CI) 0.75, 3.51]; p = 0.216}. There were no statistically significant differences in the key secondary endpoints, but a numerically higher proportion of patients in the reparixin group were alive and free of respiratory failure at Day 60 (88.7% versus 84.6%; p = 0.195), fewer required ICU admissions by Day 28 (15.8% versus 21.7%; p = 0.168), and a higher proportion recovered by Day 28 compared with placebo (81.6% versus 74.9%; p = 0.167). Fewer patients experienced adverse events with reparixin than placebo (45.6% versus 54.5%), most mild or moderate intensity and not related to study treatment. Conclusions: This trial did not meet the primary efficacy endpoints, yet reparixin showed a trend toward limiting disease progression as an add-on therapy in COVID-19 severe pneumonia and was well tolerated. Trial registration: ClinicalTrials.gov: NCT04878055, EudraCT: 2020-005919-51

    Mental Health Around the Transition to First Birth: Does Medically Assisted Reproduction Matter?

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    Previous research has shown that childbearing is associated with short-term improvements in women's subjective well-being but that these effects depend on the timing and quantum of the birth as well as on the parents' education and socioeconomic status. These studies did not address whether and, if so, how this effect varies according to the mode of conception. This represents an important knowledge gap, given that conceptions through medically assisted reproduction (MAR) have been increasing rapidly in recent decades, exceeding 5% of live births in some European countries. Drawing on nine waves (2009/2010-2017/2018) of the UK Household Longitudinal Study, we use distributed fixed -effects linear regression models to examine changes in women's mental health before, during, and after natural and MAR conceptions. The results show that the mental health of women who conceived naturally improved around the time of conception and then gradually returned to baseline levels; comparatively, the mental health of women who conceived through MAR declined in the year before pregnancy and then gradually recovered. The findings also indicate that women's happiness decreased both two years and one year before an MAR conception and then increased above the baseline in the year of pregnancy. We further show that the deterioration in mental health and subjective well-being before an MAR conception affects both partners, which could be part of a longer process in which the partners potentially suffer from stress related not solely to the MAR treatments themselves but also to the experience of subfertility

    Shaping Calcite Crystals by Means of Comb Polyelectrolytes Having Neutral Hydrophilic Teeth

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    Comb polyelectrolytes (CPs) having neutral hydrophilic teeth, similar to double hydrophilic block copolymers, are a powerful tool to modify the chemical-physical properties of inorganic crystalline materials. One of their main applications is in concrete technology, where they work as superplasticizers, particle-dispersing agents. Here, CPs, having the same poly(acrylic acid) (PAA) backbone chain and differing in the grafting with methoxy poly(ethylene glycol) chains (MPEG) of two molecular weights, were used to investigate the influence of tooth chains in polymer aggregation and in control on morphology and aggregation of calcite particles. These polymers aggregate, forming interpolymer hydrogen bonds between carboxylic groups and ether oxygen functionalities. The presence of calcium ions in solution further enhances aggregation. Crystallization experiments of calcite in the presence of CPs show that the specificity of interactions between polymers and crystal planes and control on aggregation and size of particles is a function of the content and chain length of the MPEG in the PAA backbone. These parameters limit and can make specific the electrostatic interactions with ionic crystalline planes. Moreover, the mechanism of crystallization, classical or nonclassical, is addressed by the CP structure and concentration. These findings have implications in the understanding of the complex chemical processes associated to concrete superplasticizers action and in the study of the biomineralization processes, where biological comb polyelectrolytes, the acidic glycoproteins, govern formation of calcitic structures

    Medically assisted reproduction and mental health: a 24-year longitudinal analysis using Finnish register data

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    Background: Medically assisted reproduction (MAR) can negatively impact women's mental health, particularly when the treatments do not result in a live birth. While the number of women relying on MAR to conceive has grown rapidly, our knowledge about the mental health effects before, during, and after treatment is limited. / Objective: To understand the long-term association between medically assisted reproduction and mental health outcomes for women before, during and after their treatments, and according to whether the treatment resulted in a live birth or not. / Study design: Using Finnish register data for the period 1995-2018 we estimated the probability of psychotropic purchases (antidepressants, anxiolytics, hypnotics and sedatives) for three groups of women who: 1) gave birth after natural conception (NC), 2) gave birth after MAR treatments (MAR+), or 3) underwent MAR but remained childless (MAR-). We followed women for up to 12 years before and 12 years after the reference date which corresponded to the conception date for women who had a first live birth either after a natural or a MAR conception, or the date of the last MAR treatment for women with no live birth by the end of 2017. We estimated linear probability models before and after the adjustment for socio-demographic characteristics. / Results: The results show that women who did not have a live birth after undergoing MAR treatments purchased more psychotropics than women who gave birth after conceiving naturally or through MAR, and that these differences did not attenuate over time. 12 years after the reference date 17.73% (95% CI: 16.82-18.63) of MAR- women purchased psychotropics, versus 11.11% of NC (95% CI: 10.98-11.26) and 12.17% (95% CI: 11.65-12.69) of MAR+ women. In addition, women who conceived naturally and through MAR had very similar psychotropic use patterns from three years before conception to four years after, and over the long term. Adjustment for women's socio-demographic characteristics did not change the results. / Conclusions: The similarities in psychotropic purchases of women who had a live birth, whether naturally or through MAR, suggest that the higher psychotropic use among women who remained childless after undergoing MAR were likely driven more by involuntary childlessness than by treatment-related stress. The results highlight the importance of counselling for women undergoing MAR treatments, especially if their attempts to conceive are unsuccessful
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