Marble hydrophobicity tuned by Si-based coatings

Hydrophobic polymers applied on stone materials increase their durability against undesired weathering processes [1]. The achievement of a certain degree of surface hydrophobicity (reducing the water permeation) constitutes one of the main research focuses [2]. Herein, two commercial Si-based resins (e.g. Alpha\uaeSI30 and Bluesil\uaeBP9710), directly applied on Carrara marble substrates and a silanization process, by using trichloromethylsilane (TCMS), were adopted. Contact angle measurements were carried out to evaluate the hydrophobic features. Hence, since only in the case of TCMS a good hydrophobicity was achieved (\uf071 around 150\ub0), two commercial polysiloxane-based additives (e.g. TegoPhobe 1500N and TegoPhobe 1650) were added respectively to Alpha\uaeSI30 and Bluesil\uaeBP9710, according to their chemical compatibility. These auxiliary substances allowed to decrease the wettability features of marble. Furthermore, since all the investigated coatings could be used as stone materials protective agents, water capillary absorption and vapor permeability tests were performed. Also, in this case, TCMS revealed to be the most performing one among the adopted silane-based resins, thanks to the drastic reduction of absorbed water and the decrease of vapor permeability within the threshold value of 50%. Finally, the coatings stability was evaluated by accelerated ageing tests. References [1] Cappelletti G., Fermo P., Pino F., Pargoletti E., Pecchioni E., Fratini F., Ruffolo S.A., La Russa M.F., On the role of hydrophobic Si-based protective coatings in limiting mortar deterioration, Environ Sci Pollut Res, 22 (2015) 17733\u201317743. [2] Cappelletti G., Fermo P., Camiloni M., Smart hybrid coatings for natural stones conservation, Progress in Organic Coatings 78 (2015) 511\u2013516

Age does not count: resilience of quantity processing in healthy ageing

Quantity skills have been extensively studied in terms of their development and pathological decline. Recently, numerosity discrimination (i.e., how many items are in a set) has been shown to be resilient to healthy ageing despite relying on inhibitory skills, but whether processing continuous quantities such as time and space is equally well-maintained in ageing participants is not known. Life-long exposure to quantity-related problems may progressively refine proficiency in quantity tasks, or alternatively quantity skills may decline with age. In addition, is not known whether the tight relationship between quantity dimensions typically shown in their interactions is preserved in ageing. To address these questions, two experimental paradigms were used in 38 younger and 32 older healthy adults who showed typical age-related decline in attention, executive function and memory tasks. In both groups we first assessed time and space discrimination independently using a two-choice task (i.e., “Which of two horizontal lines is longer in duration or extension?”), and found that time and space processing were equally accurate in younger and older participants. In a second paradigm, we assessed the relation between different quantity dimensions which were presented as a dynamic pattern of dots independently changing in duration, spatial extension and numerosity. Younger and older participants again showed a similar profile of interaction between number, cumulative area and duration, although older adults showed a greater sensitivity to task-irrelevant information than younger adults in the cumulative area task but lower sensitivity in the duration task. Continuous quantity processing seems therefore resilient to ageing similar to numerosity and to other non-quantity skills like vocabulary or implicit memory; however, ageing might differentially affect different quantity dimensions

The hydrophobicity modulation of glass and marble materials by different Si-based coatings

Hydrophobic polymers applied on hydroxylated surfaces increase their durability against undesired weathering processes. The achievement of a certain degree of surface hydrophobicity (reducing the water permeation) constitutes one of the main research focuses. Herein, two commercial Si-based resins (e.g. Alpha\uaeSI30 and Bluesil\uaeBP9710), directly applied on both glass and Carrara marble substrates, and a silanization process by using trichloromethylsilane (TCMS) were adopted. Contact angle measurements together with hysteresis determination and Surface Free Energy (SFE) were carried out to evaluate the hydrophobic features. Hence, since only in the case of TCMS a good hydrophobicity was achieved (\uf071 around 150\ub0), two commercial polysiloxane-based additives (e.g. TegoPhobe 1500N and TegoPhobe 1650) were added respectively to Alpha\uaeSI30 and Bluesil\uaeBP9710, according to their chemical compatibility. These auxiliary substances allowed to decrease the wettability features of either glass or marble. Furthermore, since all the investigated coatings could be used as stone materials protective agents, water capillary absorption and vapor permeability tests were performed. Also in this case, TCMS revealed to be the most performing one among the adopted silane-based resins, thanks to the drastic reduction of absorbed water and the decrease of vapor permeability within the threshold value of 50%. Finally, the coatings stability was evaluated by accelerated ageing tests

Graphene Oxide-Based Hybrids for Chemiresistive VOCs Sensors

INTRODUCTION The sensing of gas molecules is of primary importance for environmental monitoring, control of chemical processes, medical applications, and so on1. In recent years, graphene-based gas sensors have attracted much attention due to enhanced graphene thermo-electric conductivity, surface area and mechanical strength. Thus, different structures have been developed and high sensing performances and room temperature working conditions were achieved1. However, they still suffer from several problems, which could be overcome by covering the graphene surface with metal oxide nanoparticles2. Furthermore, studies regarding the detection of Volatile Organic Compounds (VOCs) are still at the beginning1. Hence, the present work will be aimed at: i) optimizing the synthetic routes of ad hoc composite VOCs sensing materials (based on graphene oxide/SnO2 or ZnO hybrids) and their deep physico-chemical characterizations; ii) engineering the gas sensor device; and iii) evaluating the sensing performances at both high and mild temperatures (also exploiting the UV light) towards gaseous ethanol, acetone and ethylbenzene. EXPERIMENTAL/THEORETICAL STUDY Starting from pure graphite, graphene oxide (GO) powder was synthesized by adopting the Hummer\u2019s modified method2. The synthetic route was deeply investigated by modulating both the starting carbon material (powder or flakes graphite) and the concentration of the H2O2 (i.e. the quenching/oxidizing agent), thus tailoring the final GO surface/structural properties. Once optimized this step, SnO2 or ZnO were grown on its surface by a hydrothermal method, varying the starting salt precursor/GO weight ratio (ZnxGO or SnxGO, x = 4, 8, 16, 32). For comparison, pure SnO2 and ZnO (both commercial and home-made) were also tested. Several physico-chemical techniques have been used to characterize all the as-prepared nanopowders, such as XRPD, BET, Raman, FTIR, XPS, TEM and electrochemical analyses (CV and EIS). Subsequently, a homogeneous layer was deposited by spraying technique onto Pt-Interdigitated Electrodes (IDEs) starting from an ethanol suspension of each sample (2.5 mg mL-1). Then, gaseous ethanol, acetone and ethylbenzene (the more interesting one, being nowadays the less studied VOC) were sensed by using a Linkam Scientific stage, equipped with an electrochemical workstation for the chronoamperometric measurements. RESULTS AND DISCUSSION The effective synthesis of graphene oxide sheets and, subsequently, the growth of metal oxide nanoparticles on its surface were confirmed by exploiting different physico-chemical techniques. As concerns the VOCs sensing analyses, we obtained very promising results (in terms of both response/recovery time and sensibility down to ppb levels) for either pure and hybrid materials at 350\ub0C, and at lower temperatures (150\ub0C to RT, by exploiting UV light) for the graphene-based samples (Figure 1), thanks to the presence of the carbon material.Furthermore, a similar behavior has been noticed towards acetone and ethylbenzene pollutants. CONCLUSION Very promising results have been obtained with graphene oxide-based materials, which reveal to be more performing than the corresponding pure samples. Hence, these powders may represent very potential candidates for the gas sensing of highly toxic VOCs traces, both for environmental and medical diagnosis1 purposes

Durable Modified Polyacrylic Coatings for Cultural Heritage Protection

INTRODUCTION Deterioration phenomena of ancient and modern stone cultural heritage are natural and unrestrainable decay processes mainly arising from water adsorption and percolation into stone building materials1. Once water attacks and penetrates stone surfaces, several chemical, physical and biological degradation processes can occur altering significantly, and in some cases even irreversibly, the properties of stone materials. The application of hydrophobic coatings to stone surfaces is mandatory to protect stone artefacts from the deleterious effects occurring in the case of water exposition. The protective agent must possess several features, i.e. high compatibility with the substrate, high durability, transparency, easiness of application and removal, water-repellency, capability to avoid the attack of organic and inorganic contaminants; moreover, it should be permeable to water vapor. The aim of the present work was to synthesize new polymer coatings as stone protective with satisfactory water repellent properties and improved durability, thanks to the combined use of fluorinated and long alkyl chain monomers and without the use of any photo stabilizers agents. EXPERIMENTAL/THEORETICAL STUDY New types of polymer protectives were prepared via free radical polymerization between either 1H,1H,2H,2H-Perfluoro-octyl-methacrylate (POMA) or commercial stearyl methacrylate (STEA, Sigma Aldrich) and methacrylic monomers (methyl, MMA, and n-butyl, nBuMA, methacrylates)2,3. Specifically, POMA was synthesized via esterification reaction using methacryloyl chloride and 1H,1H,2H,2H-Perfluoro-1-octanol. RESULTS AND DISCUSSION The properties of the home-made hydrophobizing polymers in terms of macromolecular structure, molecular weights, thermal features and water repellency were determined. Furthermore, the long-term behavior of these polymeric protective agents was estimated by means of accelerated aging tests exploiting UV radiations (in according to UNI 10925:2001 standard method for 100h, 315-400 nm for UVA rays and 280-315 nm for UVB ones). Their behavior over time was checked via Size Exclusion Chromatography (SEC) by evaluating Mn and D data of aged polymeric samples (Table 1) and by Fourier Transform Infrared (FT-IR) spectroscopy. By evaluating Mn and D data reported in Table 1, all the synthesized polymers seem to be unaffected by UV aging. Thus, the present stable resins were applied on both natural (Botticino marble) and artificial (mortar) stone substrates and their wetting properties together with their absorption by capillarity and water vapour permeability were successfully assessed and compared. All the covered substrates show an increase of water contact angle of around 50\ub0 and a decrease in water absorption and permeation of about 50% and 20%, respectively. Lastly, in order to evaluate the stability of the applied coatings towards degradation induced by solar radiation and interaction with the atmospheric pollution, exposure to a typical polluted urban environment for some months have been carried out. For this purpose, the following analyses have been performed: contact angle measurements, SEM-EDS (Scanning Electron Microscopy with X-ray microanalysis), IC (Ion Chromatography), and colorimetric tests by CIELab elaboration. CONCLUSION The use of polymeric protectives is very advantageous in fields when the hydrophobic properties and high chemical stability are required. Within this context, the use of polymer resins bearing methacrylic and fluorinated monomers along the polymeric chain can be a way to create tailor-made water repellent materials with enhanced durability, without the addition of any stabilizing agent

Role of high dose octreotide LAR for the treatment of GEP-NETs

Neuroendocrine Tumours (NETs) are a heterogeneous group of rare neoplasms that account for 0,5% of all malignancies. The increased incidence observed in the last few decades may be accounted for by increased awareness, improved diagnostic tools and a revision in the definition. The main primary sites are the gastro-entero-pancreatic (GEP) tract (62-67%), and the lung (22-27%). In patients with GEP-NETs, the strongest predictor of 5-years survival is the staging. An adequate clinical management of GEP-NETs should be multidisciplinary and should aim at assuring a good quality of life. Somatostatin (sst) analogues are widely used in these tumours, which often express sst receptors, since they are demonstrated to reduce clinical symptoms and tumour growth. Herein we explore the usefulness of doubling octreotide LAR dose in selected patients after escaping from symptoms control and/or tumour stabilization in course of treatment with standard dose

Detection of VOCs Traces by Graphene Oxide-Metal Oxide Gas Sensors

The sensing of gas molecules is of fundamental importance for environmental monitoring, control of chemical processes, medical applications, and so on [1-3]. In recent years, graphene-based gas sensors have attracted much attention due to enhanced graphene thermo-electric conductivity, surface area and mechanical strength. Thus, different structures have been developed and high sensing performances and room temperature working conditions were achieved [2,4]. However, they still suffer from several problems, which could be overcome by covering the graphene surface with metal oxide nanoparticles [2]. Furthermore, studies regarding the detection of Volatile Organic Compounds (VOCs) are still at the beginning [3]. Hence, the present work will be aimed at: i) optimizing the synthetic routes of ad hoc composite VOCs sensing materials (based on graphene oxide/SnO2 or ZnO hybrids) and their deep physico-chemical characterizations; ii) engineering the gas sensor device; and iii) evaluating the sensing performances at both high and mild temperatures (also exploiting the UV light) towards gaseous ethanol, acetone and ethylbenzene. Starting from pure graphite, graphene oxide (GO) powder was synthesized by adopting the Hummer\u2019s modified method [5]. The synthetic route was deeply investigated by modulating both the starting carbon material (powder or flakes graphite) and the concentration of the H2O2 (i.e. the quenching/oxidizing agent), thus tailoring the final GO surface/structural properties (TEM images in Fig. 1a and 1b). Once optimized this step, SnO2 or ZnO were grown on its surface by a hydrothermal method, varying the starting salt precursor/GO weight ratio between 4 and 32 (Fig. 1c and 1d). For comparison, pure SnO2 and ZnO (both commercial and home-made) were also tested. Several physico-chemical techniques have been used to characterize all the as-prepared nanopowders, such as XRPD, Raman, FTIR, XPS and TEM analyses. Subsequently, a homogeneous layer was deposited by spraying technique onto Pt-Interdigitated Electrodes (IDEs) starting from an ethanol suspension of each sample (2.0\u20132.5 mg mL-1). Then, gaseous ethanol, acetone and the less studied ethylbenzene were sensed, obtaining very promising results (in terms of both response/recovery time and sensibility down to ppb levels) for either pure and hybrid materials at 350\ub0C, and at lower temperatures (150\ub0C to 30\ub0C) for the graphene-based samples. Hence, these powders may represent very potential candidates for the gas sensing of highly toxic VOCs traces, both for environmental [1] and medical [3] diagnosis purposes

New insight on tomato seed priming with Anabaena minutissima phycobiliproteins in relation to Rhizoctonia solani root rot resistance and seedling growth promotion

Cyanobacteria phycobiliproteins (PBPs) are already exploited in the food industries and for biotechnological applications but not in the agricultural field. Different concentrations (0.6 - 4.8 mg/mL) of Anabaena minutissima PBPs were applied to tomato seed to study their priming effect against the soil-borne fungal pathogen Rhizoctonia solani and in promoting plant growth. PBPs increased seedling emergence and vigour, showed activity against root rot disease (67%), and enhanced plant dry weight, length, and height. Generally, no dose effect has been observed except for dry weight (55% at 4.8 mg/mL). Seed treatment primed seeds and seedlings by leading to the activation of defence responses raising phenol (26% in hypocotyls) and flavonoid (26 and 45% in hypocotyls and epicotyls, respectively) contents and chitinase (4-fold at 2.4 and 4.8 mg/mL in hypocotyls) and beta-1,3-D-glucanase (up to about 2-fold at all doses in epicotyls) activities. Micro-Attenuated Total Reflection Fourier Transform Infrared revealed changes in functional groups of primed seeds, hypocotyls and exudates released into the agar because of treatment. Protein extract from PBP-primed seedlings inhibited mycelial growth (67% for epicotyl proteins) and caused morphological alterations in hyphae. This research emphasizes the potential priming role of PBPs applied by seed treatment against soil-borne pathogens

Takotsubo cardiomyopathy and sepsis: a systematic review

Takotsubo cardiomyopathy (TTC) is characterized by a systolic dysfunction localized in the apical and medial aspect of the left ventricle. It is usually related to physical or emotional stress. Recent evidence highlighting the role of infection led us to analyze the links between TTC and sepsis. A systematic review of the literature was undertaken to assess any trends in clinical findings, diagnosis, and outcomes in such patients. We identified 23 selected papers reporting a total of 26 patients, having sepsis, in whom TTC occurred. For each case, we collected data identifying population characteristics, source of sepsis, clinical disease description, and the results of cardiovascular investigations. The majority of patients were females (n = 16), mean age was 62.8 (14.0 standard deviation) years, and clinical outcome was favorable in 92.3% of the cases once the management of sepsis was initiated. A better understanding of the mechanisms of sepsis-associated TTC may generate novel strategies to treat the complications of this cardiomyopathy and may even help predict and prevent its occurrence