Brownian thermal noise associated with highly reflective mirror coatings is a fundamental limit for several precision experiments, including gravitational-wave detectors. Recently, there has been a ...worldwide effort to find mirror coatings with improved thermal noise properties that also fulfill strict optical requirements such as low absorption and scatter. We report on the optical and mechanical properties of ion-beam-sputtered niobia and titania-niobia thin films, and we discuss application of such coatings in current and future gravitational-wave detectors. We also report an updated direct coating thermal noise measurement of the HR coatings used in Advanced LIGO and Advanced Virgo, and the observation of a discrepancy between ring-down measurements and thermal-noise estimations of mechanical loss in highly reflective mirror coatings. This discrepancy might be ascribed either to a dissipation of the silica layers considerably higher than expected or to an unexplained excess loss of stacked layers.
The association between PrP gene variations and scrapie susceptibility was studied in a single herd of Ionica breed goats. The entire herd comprised 100 animals, 11 of which were clinically affected ...and showed pathological prion protein (PrP(Sc)) deposition in both their central nervous system (CNS) and lymphoreticular system (LRS). Among asymptomatic goats, nine harboured PrP(Sc) in both CNS and LRS, 19 showed PrP(Sc) only at the LRS level and 61 animals had no PrP(Sc) deposition. Genetic analysis of the PrP gene coding sequence revealed the presence of several polymorphisms, namely G37V, T110P, H143R, R154H, Q222K and P240S. Silent polymorphisms were also found at codons 42, 138, 219 and 232. The effect of PrP polymorphism on scrapie susceptibility was assessed by comparing the genotype distribution at each locus among animals with different pathogenetic and clinical disease stages. Significant differences in the distribution of genotypes were observed for codons 154 and 222, with polymorphism at codon 154 modulating susceptibility to scrapie and lysine at codon 222 being associated with scrapie resistance. The allelic variant encoding lysine at position 222 could be a valuable candidate to select in the framework of appropriate breeding programmes for scrapie resistance in goats.
Bone has a sophisticated architecture characterized by a hierarchical organization, starting at the sub-micrometre level. Thus, the analysis of the mechanical and structural properties of bone at ...this scale is essential to understand the relationship between its physiology, physical properties and chemical composition. Here, we unveil the potential of Brillouin-Raman microspectroscopy (BRaMS), an emerging correlative optical approach that can simultaneously assess bone mechanics and chemistry with micrometric resolution. Correlative hyperspectral imaging, performed on a human diaphyseal ring, reveals a complex microarchitecture that is reflected in extremely rich and informative spectra. An innovative method for mechanical properties analysis is proposed, mapping the intermixing of soft and hard tissue areas and revealing the coexistence of regions involved in remodelling processes, nutrient transportation and structural support. The mineralized regions appear elastically inhomogeneous, resembling the pattern of the osteons' lamellae, while Raman and energy-dispersive X-ray images through scanning electron microscopy show an overall uniform distribution of the mineral content, suggesting that other structural factors are responsible for lamellar micromechanical heterogeneity. These results, besides giving an important insight into cortical bone tissue properties, highlight the potential of BRaMS to access the origin of anisotropic mechanical properties, which are almost ubiquitous in other biological tissues.
•Zinc-promoted materials exhibits increased self-bleaching activity.•Improved surface area does not improve the self-bleaching.•Surface insulating calcium hydroxide layer limits charge-transfer ...processes.•Multiple-heterojunctions contributed to a remarkable photoactivity enhancement.
The Venetian marmorino is a traditional material used for wall coating in Venice city, composed of hydrated lime and marble powders, and is part of the cultural heritage of the city. Several surface damage processes can negatively affect its aesthetic properties, such as the formation of stain deposits of different origin (i.e. pollution, bio-deterioration, vandalism) which eventually change the colour of this material. An appealing way to avoid these deposits rely on inducing self-bleaching features by introducing a photocatalyts on this material. In the present work, TiO2-based and ZnO-based photocatalysts were introduced within the marmorino, then evaluating how the addition of these materials influenced the compositional, structural and morphological properties though X-ray diffraction (XRD), N2 physisorption and electron microscopy (SEM). ZnO-modified samples, which exhibited comparable morphological and structural properties, were further analyzed to get information concerning the surface compostion and the opto-electronic properties, through attenuated total reflectance (ATR) spectroscopy and photoluminescence (PL), respectively, in turn related to the presence of defects and heterojunctions. The self-bleaching activity was evaluated by irradiation in mild condition (room temperature) in air using a dye as model stain compound. Finally, the morphological, surface and opto-electronic properties of the photocatalyst-modified marmorino were correlated to the activity results, aiming to understand how they can influence the material performances, and thus how to design an active self-bleaching Venetian marmorino.
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The unconventional infectious agents of transmissible spongiform encephalopathies (TSEs) are prions. Their infectivity co-appears with PrP
, aberrant depositions of the host's cellular prion protein ...(PrP
). Successive heat treatment in the presence of detergent and proteolysis by a keratinase from Bacillus licheniformis PWD-1 was shown before to destroy PrP
from bovine TSE (BSE) and sheep scrapie diseased brain, however data regarding expected reduction of infectivity were still lacking. Therefore, transgenic Tgbov XV mice which are highly BSE susceptible were used to quantify infectivity before and after the bovine brain treatment procedure. Also four immunochemical analyses were applied to compare the levels of PrP
. After heating at 115 °C with or without subsequent proteolysis, the original BSE infectivity of 10
ID
g
was reduced to a remaining infectivity of 10
ID
g
while strain characteristics were unaltered, even after precipitation with methanol. Surprisingly, PrP
depletion was 5-800 times higher than the loss of infectivity. Similar treatment was applied on other prion strains, which were CWD1 in bank voles, 263 K scrapie in hamsters and sheep PG127 scrapie in tg338 ovinized mice. In these strains however, infectivity was already destroyed by heat only. These findings show the unusual heat resistance of BSE and support a role for an additional factor in prion formation as suggested elsewhere when producing prions from PrP
. Leftover material in the remaining PrP
depleted BSE preparation offers a unique substrate for searching additional elements for prion infectivity and improving our concept about the nature of prions.
► Waste cooking oil was successfully deacidified over three different acid resins. ► Amberlyst®46 and Purolite®D5081 exhibit good and stable catalytic activity. ► Blending waste cooking oil and crude ...rapeseed oil lowers the viscosity. ► The lower the viscosity, the higher the esterification conversion. ► Diesel used as a solvent increase of the yields of the esterification.
The choice of waste cooking oil (WCO) as a raw material for biodiesel production is recognized to be an attractive and economic alternative to the use of vegetable oils. However, the presence of free fatty acids, impurities and high viscosity of WCO may require several pretreatments before the transesterification. In this study WCO deacidification by esterification is investigated: the results show how both Amberlyst®46 and Purolite®D5081 catalysts maintain their performance in a Carberry reactor (where catalyst is confined to minimize mechanical stress) and a slurry reactor after several recycles. A46 was tested in the free fatty acids esterification of blends of WCO with different ratios of crude rapeseed oil and diesel as a solvent. The results show how both the use of the blends with another oil with lower viscosity and diesel are both beneficial to the reaction rate and to the properties of the finished biodiesel.
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•Co and Co/Ru-based catalysts with 5%wt. Co, 10%wt. Co and 0.4%wt. Ru supported on SiO2 for the Fischer-Tropsch process have been synthesized by Flame Spray Pyrolysis (FSP).•5wt% of ...Co sample did not show any activity toward the FT synthesis while 10%wt of Co and 10%wt of Co − 0.4%wt of Ru samples are suitable catalysts for GTL process.•10%wt sample showed a great stability in function of TOS at T=250°C in terms of reactants conversion and products selectivity.•Products selectivity to CO2, CH4, light hydrocarbons (<C7) and heavy hydrocarbons (>C7) remains essentially unchanged at different temperatures.
Flame spray pyrolysis (FSP) is an innovative and scalable technique, used to synthesize monometallic and bimetallic Co-Ru catalysts with 5%wt. Co, 10%wt. Co and 0.4%wt. Ru supported on SiO2 active in the Gas-to-Liquids (GTL)-Fischer-Tropsch (FT) process, which converts syngas to hydrocarbons. The catalysts were characterized by TEM, FE-SEM-EDX, TPR, XRD and N2 adsorption/desorption. All the three samples have been tested in a fixed bed FT-bench scale plant. Results demonstrated that the 5%wt. Co catalyst was not active toward FT synthesis, while samples containing 10% wt. Co and 10% wt. Co - 0.4% wt. Ru were suitable candidates for the GTL-FT process. With an increase in temperature, the CO conversion increased, the product selectivity remained unchanged, and the 10%wt. Co catalyst showed higher stability as a function of time-on-stream (TOS) with respect to traditionally prepared materials. The addition of 0.4%wt. of Ru improved the performance in terms of CO conversion and C2+ yield.
•Synthesis strategy of CaO incorporation into calcium aluminates was approached.•Three innovative sorbents (M1, M2, M3) were synthesized and characterized.•Sorption capacity of developed sorbents was ...evaluated in multi-cycle processes.•M3 sorbent showed best performance, much higher than conventional CaO ones.•M3 sorbent functionality in SE-SR process was verified.
Greenhouse gases emission of power generation plants will be continuously tightened to achieve European targets in terms of CO2 emissions. In particular, the switching to a sustainable power generation using fossil fuels will be strongly encouraged in the future. In this context, sorption-enhanced steam reforming (SE-SR) is a promising process because it can be implemented as a CCS pre-combustion methodology. The purpose of this study is to develop and test innovative materials in order to overcome main limitations of standard CaO sorbent, usually used in the SE-SR process. The investigated innovative sorbents are based on incorporation of CaO particles into inert materials which significantly reduce the performance degradation. In particular, sorbent materials based on calcium aluminates were considered, investigating different techniques of synthesis. All synthesized materials were packed, together with the catalyst, in a fixed bed reactor and tested in sorption/regeneration cycles. Significant improvements were obtained respect to standard CaO regarding sorption capacity stability exhibited by the sorbent.
The resolution of the three-dimensional structure of infectious prions at the atomic level is pivotal to understand the pathobiology of Transmissible Spongiform Encephalopathies (TSE), but has been ...long hindered due to certain particularities of these proteinaceous pathogens. Difficulties related to their purification from brain homogenates of disease-affected animals were resolved almost a decade ago by the development of in vitro recombinant prion propagation systems giving rise to highly infectious recombinant prions. However, lack of knowledge about the molecular mechanisms of the misfolding event and the complexity of systems such as the Protein Misfolding Cyclic Amplification (PMCA), have limited generating the large amounts of homogeneous recombinant prion preparations required for high-resolution techniques such as solid state Nuclear Magnetic Resonance (ssNMR) imaging. Herein, we present a novel recombinant prion propagation system based on PMCA that substitutes sonication with shaking thereby allowing the production of unprecedented amounts of multi-labeled, infectious recombinant prions. The use of specific cofactors, such as dextran sulfate, limit the structural heterogeneity of the in vitro propagated prions and makes possible, for the first time, the generation of infectious and likely homogeneous samples in sufficient quantities for studies with high-resolution structural techniques as demonstrated by the preliminary ssNMR spectrum presented here. Overall, we consider that this new method named Protein Misfolding Shaking Amplification (PMSA), opens new avenues to finally elucidate the three-dimensional structure of infectious prions.
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