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In this study, a multimethodological analysis involving optical and physical/chemical diagnostic techniques and 3D photogrammetric survey was successfully applied, for the first time, on the large oil on canvas St. Michael defeating Evil painting by Mattia Preti, located inside the Church of the Immaculate Conception of Sarria (Floriana) in Malta. Pigmenting agents, binder media, and raw materials were first characterized, both at elemental and molecular scales, through X-ray fluorescence spectroscopy (XRF), optical stereo microscopy (SM), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectroscopy (FT-IR), and gas chromatography coupled with mass spectrometry (GC-MS). The main goal was to properly identify the execution technique of this famous painter, the artist's palette, and possible nondocumented interventions. The 3D photogrammetric survey, on the other side, allowed us to noninvasively evaluate the extension of the areas that experienced restorations, and to properly map the domains of the different canvasses observed. The joints between canvasses suggested that the painting was folded and rolled up. In addition, the employment of a thermal camera gave evidence of the different consolidating material injection points used during the restoration to strengthen the painting. The obtained results offer useful information for the development of optimized restoration and conservation strategies to be applied and provide, at the same time, answers to open questions related to provenance and dating of the investigated artwork.

Plasters and mortars of the Church of the Annunciation (Tortorici, Sicily) were characterized, for the first time, both at the elemental and molecular levels, by means of portable X-ray fluorescence (XRF) and Raman spectroscopy, to achieve information on the “state of health” of the whole structure. The understanding of their degradation mechanisms and the identification of consequent degradation patterns can define the environmental factors responsible for interpreting the potential pathological forms that can impact the general building vulnerability. In this sense, the results obtained in this article provide relevant information to identify and address both the characterization of building materials and the fundamental causes of their deterioration. At the same time, if coupled with the attempt to supply a chronological order of the major restoration interventions carried out on the investigated site, they provide new insights to calibrate the models for building vulnerability studies., peer-reviewed

Plasters and mortars of the

Cellulose nano-sponges (CNS), obtained by cross-linking TEMPO oxidized and ultra-sonicated cellulose nano-fibers (TOUS-CNFs) with branched polyethyleneimine (bPEI), underwent here a systematic small angle neutron scattering investigation, by varying the amount of cross-linker and the water content. The aim was to provide experimental evidence of nano-porosity in the TOUS-CNF network of these nano-sponges (CNSs) by investigating the water nano-confinement geometries in the adsorbent material. Moreover, we also verified how the breaking/reformation of specific intermolecular hydrogen bond interactions between water and the chemical groups present in the architecture of the CNSs could contribute to regulate the water adsorption process observed at macroscopic level. The analysis of the experimental data, performed in terms of the correlation length model, allowed us to extract the short-range correlation length ξ, interpreted as a very first indirect estimation of the effective nano-dimension of the cavities produced by the cross-linking of the reticulated cellulose nano-fibers. From the model, power-law (n) and Lorentzian (m) exponents have been also obtained, associated with the density of TOUS-CNFs at high (larger than hundreds of A) and low (~ 10–100 A) spatial scales, respectively. These parameters were all sensitive to the structural variations induced by the progressive uptake of water on the bPEI/TOUS-CNF sponges with different bPEI:TOUS-CNF (w/w) ratios. Finally, we investigated the effect of the addition of citric acid in the CNS formulation, confirming its role in increasing cross-linking density and sponge rigidity. The obtained results appear crucial in order to rationalize the design of these sponges and to track the changes in the ability of the final products as efficient nano-confinement systems for water.

In this article, an investigation of the natural radioactivity content of pyroclastic products from Mt. Etna, eastern Sicily, Southern Italy, was carried out. In particular, the assessment of the average activity concentration of the investigated radionuclides, related to the mineralogical phase composition of the analyzed samples, and the radiological health risk for the population, was performed. High Purity Germanium (HPGe) gamma-ray spectrometry was employed in order to quantify the average specific activity of 226Ra, 232Th, and 40K natural radioisotopes. The absorbed gamma dose rate (D), the radium equivalent activity (Raeq), the hazard indices (Hin and Hex), the annual effective dose equivalent outdoor (AEDEout), and the excess lifetime cancer risk (ELCR) were also estimated in order to assess any possible radiological hazard for the population. In our case, they were found to be lower than the maximum recommended values for the population members, thus reasonably excluding radiological hazard effects. Moreover, the identification of the source of the aforementioned naturally occurring radionuclides was attempted by X-ray Diffraction (XRD) and Micro-Raman Scattering (MRS), thereby recognizing the main radioisotope-bearing minerals present in the investigated pyroclastic products. Finally, Pearson correlation, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were performed by processing observed radioactivity and radiological parameters in order to determine their correlation with the sampling locations.

In this article, the authors report experimental results obtained for the assessment of the 226Ra content in 80 drinking water samples from the Calabria region, Southern Italy. The activity concentration, measured with the Perkin Elmer Tricarb 4910 TR Liquid Scintillation Counter (LSC) setup, was compared with the reference values reported in the Italian Legislative Decree 28/2016 in order to evaluate any possible radiological health hazards for the population in terms of 226Ra content due to the ingestion of the investigated drinking water. The obtained results put in evidence that the average 226Ra specific activity is lower than the LSC minimum detectable activity (MDA) in all cases, thus, excluding any radiological risk. They also represent the main reference for the investigated area and can be used as a baseline to extend this investigation to the whole region.

A combination of Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR) and 2D correlation analysis (2D-COS) was applied here for the first time in order to investigate the temperature-dependent dynamical evolution occurring in a particular type of inclusion complex, based on sulfobutylether-β-cyclodextrin (SBE-β-CD) as hosting agent and Coumestrol (7,12-dihydorxcoumestane, Coum), a poorly-soluble active compound known for its anti-viral and anti-oxidant activity. For this purpose, synchronous and asynchronous 2D spectra were calculated in three different wavenumber regions (960–1320 cm−1, 1580–1760 cm−1 and 2780–3750 cm−1) and over a temperature range between 250 K and 340 K. The resolution enhancement provided by the 2D-COS offers the possibility to extract the sequential order of events tracked by specific functional groups of the system, and allows, at the same time, the overcoming of some of the limits associated with conventional 1D FTIR-ATR analysis. Acquired information could be used, in principle, for the definition of an optimized procedure capable to provide high-performance T-sensitive drug carrier systems for different applications.

Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR), combined with a 2D correlation analysis, was here employed to investigate temperature-induced spectral changes occurring in a particular type of novel cellulosic-based nano-material prepared using 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO) oxidized and ultra-sonicated cellulose nano-fibers (TOUS-CNFs) as three-dimensional scaffolds, and branched polyethyleneimine (bPEI) as cross-linking agent. The aim was to highlight the complex sequential events involving the different functional groups of the polymeric network, as well as to gain insight into the interplay between the amount of bPEI and the resulting sponge-like material, upon increasing temperature. In this framework, synchronous and asynchronous 2D spectra were computed and analyzed in three wavenumber regions (900–1200 cm−1, 1500–1700 cm−1 and 2680–3780 cm−1), where specific vibrational modes of the cellulosic structure fall, and over a T-range between 250 K and 340 K. A step-by-step evolution of the different arrangements of the polymer functional groups was proposed, with particular regard to how the cooperativity degree of inter- and intramolecular hydrogen bonds (HBs) changes upon heating. Information acquired can be useful, in principle, in order to develop a next-generation, T-sensitive novel material to be used for water remediation applications or for drug-delivery nano-vectors.

Flour investigation, in terms of physical and chemical pollutants and mineral content, is of great interest, in view of its high consumption for nutritional purposes. In this study, eleven types of flour (five samples for each one), coming from large retailers and employed by people for different cooking food purposes, were investigated through high-purity germanium (HPGe) gamma spectrometry, in order to estimate natural (40K) and anthropogenic (137Cs) radioisotope specific activity and thus, to assess the radiological risk due to the flour ingestion. Inductively-coupled plasma mass spectrometry (ICP-MS) and inductively-coupled plasma emission spectroscopy (ICP-OES) were also employed to evaluate any possible heavy metal contamination and the mineral composition, and to perform multivariate statistical analysis to deduce the flour authenticity. The evaluation of dose levels due to flour ingestion was performed, for the age category higher than 17 years, taking into account the average yearly consumption in Italy and assuming this need to be satisfied from a single type of flour as a precaution. All obtained results are under the allowable level set by Italian legislation (1 mSv y−1), thus excluding the risk of ionizing radiation effects on humans. As far as heavy metal contamination is concerned, Cd and Pb concentrations turned out to be lower than the threshold values, thus excluding their presence as pollutants. Finally, the multivariate statistical analysis allowed to unambiguously correlate flour samples to their botanical origin, according to their elemental concentrations.

This study was aimed at preparing and characterizing solid lipid nanoparticles loading rutin (RT-SLNs) for the treatment of oxidative stress-induced diseases. Phospholipon 80H® as a solid lipid and Polysorbate 80 as surfactant were used for the SLNs preparation, using the solvent emulsification/diffusion method. We obtained spherical RT-SLNs with low sizes, ranging from 40 to 60 nm (hydrodynamic radius) for the SLNs prepared starting from 2% and 5% (w/w) theoretical amount. All prepared formulations showed negative zeta-potential values. RT was efficiently encapsulated within SLNs, obtaining high encapsulation efficiency and drug content percentages, particularly for SLNs prepared with a 5% theoretical amount of RT. In vitro release profiles and analysis of the obtained data applying different kinetic models revealed Fickian diffusion as the main mechanism of RT release from the SLNs. The morphology of RT-SLNs was characterized by scanning electron microscopy (SEM), whereas the interactions between RT and the lipid matrix were investigated by Raman spectroscopy, evidencing spectral modifications of characteristic bands of RT due to the establishment of new interactions. Finally, antioxidant activity assay on human glioblastoma astrocytoma (U373) culture cells showed a dose-dependent activity for RT-SLNs, particularly at the highest assayed dose (50 μM), whereas the free drug showed the lesser activity.

Nano-sized TiO2 is widely used as photocatalysts for many applications; however, some aspects in the application in cultural heritage conservation are still unresolved. In particular, in this research, we focused our attention on nanostructured product composed by silica, polydimethylsiloxane (PDMS) and TiO2 nanoparticles. We explored the effect of variable amounts of nanoparticles on the features of coating, since this issue still has some unclear aspects. Several samples of limestone have been treated, and then, analysed. The chromatic variations induced by the treatments have been measured by colorimetric analysis, while the hydrophobic properties of coatings have been evaluated by contact angle measurements and capillary water absorption. The photocatalytic efficiency has been evaluated by methylene blue staining. In addition, two large facilities have been involved in this study, in order to obtain accurate results in a non-invasive way. On one side, middle-UV Raman spectroscopy measurements at IUVS beamline@Elettra (Trieste), by using UV synchrotron radiation (SR) source, revealed successful, with respect to conventional set-up, in order to quantify the amount of the anatase on the surface. On the other side, neutron radiography measurements at RAD Radiography Station@BNC (Budapest) permitted a sensitive monitoring of the water absorption dynamics on untreated and treated samples. (C) 2018 Elsevier Ltd. All rights reserved.

In the present article, a case study is reported regarding an investigation carried out in order to assess radioactivity concentration, heavy metals pollution and mineralogy of a beach stretch extending from Soverato to Squillace municipalities of the Ionian coast of Calabria, South of Italy, a popular tourist destination, especially in summer. The analysis of radionuclides contents was performed by using a High Purity Germanium (HPGe) gamma-ray detector, in order to quantify the average specific activity of 226Ra, 232Th and 40K natural radionuclides and 137Cs anthropogenic radioisotope. The absorbed dose rate and the annual effective dose equivalent radiological hazard indices were also estimated. Furthermore, X-ray Fluorescence (XRF) spectrometry measurements were carried out for the quantitative elemental analysis of the sand, in order to investigate any possible chemical pollution by heavy metals. For this aim, different indices such as Enrichment Factor (EF), Geoaccumulation Index (Igeo), Contamination Factor (CF) and Pollution Load Index (PLI) were applied to estimate the level of toxicity imposed on the ecosystem by the detected heavy metals. Finally, in order to identify the crystalline mineral components of the investigated sand samples, X-ray Diffraction (XRD) and Micro-Raman Scattering (MRS) measurements were carried out.

The ability of Captisol® (sulphobutylether-β-cyclodextrin, SBE-β-CD), to form inclusion complexes, both in solution and in the solid state, has been tested in order to improve some unfavorable chemical-physical characteristics, such as poor solubility in water, of a bioflavonoid, Coumestrol (Coum), well known for its anti-oxidant, anti-inflammatory, anti-fungal and anti-viral activity. In pure water, a phase-solubility study was carried out to evaluate the enhancement of the solubility of Coum and, therefore, the occurred complexation with the macrocycle. The stoichiometry and the stability constant of the SBE-β-CD/Coum complex were calculated with the phase solubility method and through the Job's plot. After that, the solid SBE-β-CD/Coum complex was prepared utilizing a kneading method. The spectral changes induced by complexation on characteristic vibrational band of Coum were complementary investigated by Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR) and Raman spectroscopy, putting into evidence the guest chemical groups involved in the “host-guest” interactions responsible of the formation and stabilization of the complex. Particular attention was paid to the C O and O H stretching vibrations, whose temperature-evolution respectively furnished the enthalpy changes associated to the binding of host and guest in solid phase and to the reorganization of the hydrogen bond scheme upon complexation. From the whole set of results, an inclusion geometry is also proposed.

In this work a combined laboratory-based and neutronographic investigation was carried out on a type of limestone, known as Pietra di Lecce stone, widely used in Italian Baroque as construction material. The limestone was treated with two different commercially-available coatings, namely nanosilica and nanolime, and artificially weathered by salt crystallization and temperature/relative humidity jumps. The aim was to provide an experimental evidence of the protective and consolidating effectiveness of the two treatments by looking at the water absorption process occurring inside the pore network of the analyzed stones. The analysis of the wetting front position revealed significant variations in the water absorption kinetics among the investigated samples, suggesting different mechanisms of interaction between the inorganic consolidants and the underlying bulk stone. Finally, a quantitative evaluation of the best effectiveness of the two products was addressed, particularly useful in view of an appropriate choice of restoration procedures to be applied to building materials.

We propose here a spectroscopic method to diagnose and differentiate inflammatory bowel diseases (IBD), such as ulcerative colitis (UC) and Crohn&rsquo, s disease (CD) with pediatric onset, in a complete noninvasive way without performing any duodenal biopsy. In particular, the Raman technique was applied to proteic extract from fecal samples in order to achieve information about molecular vibrations that can potentially furnish spectral signatures of cellular modifications occurring as a consequence of specific pathologic conditions. The attention was focused on the investigation of the amide I region, quantitatively accounting the spectral changes in the secondary structures by applying deconvolution and curve-fitting. Inflammation is found to give rise to a significant increasing of the nonreducible (trivalent)/reducible (divalent) cross-linking ratio of the protein network. This parameter revealed an excellent marker in order to distinguish IBD subjects from non-IBD ones, and, among IBD patients, to differentiate between UC and CD. The proposed methodology was validated by statistical analysis using the receiver operating characteristic (ROC) curve.

In this study a multi-technique analysis was performed on the decorated surfaces of four ancient pottery fragments dated back XIX century A.D. withdrawn from the archaeological site of the medieval Agsu town, in Azerbaijan. During the last decade, the site underwent to an extensively archaeometric investigation by means of different non-destructive, or micro-destructive, techniques. In this work we focused our attention on the characterization of the pigmenting agents and glazes at different spatial scales from elemental to microscopic domain by using portable and not-portable equipments. In particular, the elemental and molecular compositions were successfully determined by X-ray fluorescence (XRF) and Raman spectroscopy, respectively. On one side, data deriving from portable instrument were compared with those previously obtained from not-portable approach, in view of futurein situinvestigations. On the other side, the overall obtained results appear crucial for the reconstruction of the production technology used by craftsman of the past.

Tituli Picti are an ancient form of urban graffiti very common in the archaeological site of Pompeii (Naples, South—Italy). They are generally made of red pigments applied on walls of Campanian ignimbrite. This paper deals with a scientific investigation aimed to their conservation. This is a challenging task since it requires a multidisciplinary approach that includes restorers, archaeologists and conservation scientists. The study has provided suggestions on the proper way to conserve Tituli Picti over time. In the present work, several specimens of Campanian ignimbrite were painted with red earth pigment; lime and Arabic gum have been used as binders as well. Such painted stones were treated with three consolidants: a suspension of reactive nanoparticles of silica, ethyl silicate and an acrylic microemulsion. Treated and untreated specimens were subjected to thermal aging, artificial solar radiation and induced crystallization decay. It has been assessed the colorimetric variations induced by treatments. Moreover, the micromorphologic features of the consolidated surfaces have been highlighted by means of electron microscope observations. The scotch tape test allowed to compare the superficial cohesion induced by the three used products. According to the results, ethyl silicate seems to represent the most successful product.

The present paper reports a detailed experimental vibrational analysis, performed by Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR), of water confined in the pores of cellulose nano-sponges (CNSs), prepared using TEMPO oxidized and ultra-sonicated cellulose nano-fibers (TOUS-CNFs) as three-dimensional scaffolds, and branched polyethyleneimine (bPEI) as the cross-linking agent. The analysis was carried out by varying hydration and cross-linker amount, with the aim of achieving a deep understanding of how the hydrogen bond (H-bond) scheme developed by engaged water molecules can play a role in the water adsorption process already observed at macroscopic level, furnishing at the same time evidence of a nano-porous network for CNSs. In particular, the combined investigation of the FTIR-ATR spectra of CNSs hydrated with H2O and D2O allowed for the selective analysis of vibrational modes of entrapped water molecules, namely O–H stretching and HOH bending modes. As main result, a destructuring effect of hydration on the H-bond pattern of interfacial water molecules is revealed, associated to structural modifications of the bPEI/TOUS-CNFs network previously detected by small angle neutron scattering (SANS) technique. It turned out to be more relevant for low bPEI amounts. In addition, a supercooled behavior of entrapped water molecules is detected, supporting the idea of a nano-confinement for water in these systems. The obtained information can be very helpful in view of all the possible applications of bPEI-TOCNF sponges as efficient adsorbent materials, especially for water remediation.

The scientific investigation of the techniques employed by the artist, such as composition of the paints, color palette, and painting style represents a fundamental pre-requisite in order to develop proper conservation and restoration strategies. In this context, the combined use of non-destructive, non-invasive in situ image and chemical analyses was here successfully employed for the investigation of the XVIII century Madonna della Lettera panel painting from the ancient Basilian abbey of Santa Maria di Bordonaro in Messina (Italy). The used techniques were visible, infrared (IR) and false-color infrared (FCIR) photography, X-ray radiography, X-ray fluorescence (XRF) and Raman spectroscopy. The goal was to obtain accurate information on materials and techniques originally used and possible later interventions, with particular regard to the nature of the painting materials. From the results, details of the artwork useful for restoration and conservation procedures were revealed. The identification of most of the artist's palette was also achieved: Prussian blue for blue color, lead white for white, umber for the brown, cinnabar for the red, and carbon black for the black color. The composition of different preparatory substrates was also investigated. The obtained results, other than constituting a crucial step for future restoration works, can be at the same time useful for the dating of the painting, that does not report the date and the artist's signature.

The focus of this work is on addressing how the adsorption properties of cyclodextrin (CD) based polymeric hydrogels (cyclodextrin nanosponges, CDNS) can be regulated by a precise control of a crucial parameter such as the characteristic pore size of the polymer network. With this aim, Small Angle Neutron Scattering (SANS) experiments are performed on different CDNS polymer formulations, differing by (i) the chemical structure of the cross-linking agent used for the polymerization of CD, which affects the flexibility of the strands between two crosslinking junctions, (ii) the relative molar ratio of cross-linker to monomer, affecting the cross-linking density, and (iii) the dimension of the CD macrocycle, regulating the steric hindrance and number of available reactive sites on the monomer. The analysis of the experimental data in terms of a two-correlation-length model allows one to extract a correlation length ζ that is interpreted as an experimental assessment of the average mesh-size of the cross-linked polymer, confirming the effective nano-size of the cavities formed in the network of CDNS. The hydration-dependence of ζ is modelled by an empirical functional form, that provides as key parameters the swelling rate of the polymeric network and the upper limit for the mesh size of the material. These parameters are useful for the characterization of the dynamic response of the hydrogel to swelling and the maximum mesh size compatible with the chemical structure of the polymer.

This work focused on the study of decorated pottery dated back to the 16th century from the Roman archaeological site of Villa dei Quintili, a monumental complex located in the south-eastern part of Rome (Italy). A minero-petrographic and geochemical study was undertaken to analyse five archaeological samples in order to define textural features and raw materials used for their production, along with the chemical and physical composition of the superficial decorative glazed coatings. For this purpose, different analytical methods were used, such as polarising optical microscope (POM), X-ray diffraction (XRD), micro-Raman spectroscopy, X-Ray fluorescence (XRF), and electron microprobe analysis coupled with energy dispersive spectrometry (EMPA-EDS). The results of such a multidisciplinary approach allowed us to achieve important results crucial to recognise the shards as majolica of the Renaissance period, improving knowledge about manufacturing processes of these renowned painted ceramic artefacts.

Elastic incoherent neutron scattering was employed to investigate the molecular mobility of inclusion complexes, formed by two β-cyclodextrin (β-CD) derivatives, namely (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD) and methyl-β-cyclodextrin (Me-β-CD), with Genistein (Gen), a phytoestrogen having antioxidant and anticarcinogenic activities, compared to the physical mixtures and single components. The results, collected in the 20–300 K temperature range, revealed a purely vibrational dynamics up to ∼100 K, where a first anharmonic contribution, corresponding to the methyl rotational dynamics, was observed and represented by an Arrhenius trend. At higher temperatures, a second anharmonic process, also found to obey an Arrhenius-like behavior, occurred at Td and was mainly ascribed to the relaxation of the H-bond network formed by host and guest molecules. Enthalpy and entropy changes associated to the activated anharmonic processes were obtained. The picoseconds timescale dynamics was finally connected to the thermal stability, suggesting HP-β-CD as the most effective carrier for Gen.

In the present paper, we report on a recent ultraviolet (UV) Raman study in conjunction with an FTIR absorbance investigation by using synchrotron radiation techniques, performed on wall paintings samples of frescoes, stored in the charming sites of San Gennaro and San Gaudioso Catacombs (Naples, Italy). The main goal was the analysis of the pigmenting materials in order to characterize the pigmenting agents and the binders used by the artists. In this frame, the combined use of both complementary SR-based techniques played a fundamental role. In addition, in principle the characterization of the pigmenting matter could be useful for reproducing similar materials in accordance with the ancient recipes to use in any restoration process.

The present work reports a multi-analytical study, based on Polarized Optical Microscopy (POM), Scanning Electron Microscopy equipped with an Energy Dispersive X-ray detector (SEM-EDX), micro-Raman and Fourier Transform Infrared Spectroscopy (FT-IR) techniques, aimed at establishing the painting techniques and palettes used to decorate a variety of fragments of frescoes coming from Villa dei Quintili in Rome (Italy) and dated back 2nd century CE. This combined methodological approach, covering different spatial scales extending from the macroscopic to the elemental domain, revealed successful for the unambiguous identification and characterization, in non-invasive or at least micro-destructive way, of pigments, binders and stone materials. The used chromatic palette was identified as yellow ochre (goethite), carbon black (vegetal origin), probably green earth and Cu-green pigment, red ochre (haematite), lime white and Egyptian blue (cuprorivaite). Organic and inorganic binders were respectively identified as linseed oil and lime, this latter carbonated to calcium carbonate. Textural features of plasters were also evaluated in order to investigate raw materials used for their production. The obtained data revealed crucial for improving knowledge of materials and preparation methods of pigmenting agents of these fragments, taken from the warehouse of the Villa and hence of unknown provenance area, in view of their right positioning in a specific area of the archaeological complex. In fact, the characterization of the different pigments could support conservators to better identify the distribution of the frescoes among the different rooms, and to reconstruct the original aesthetics of the Villa during the Quintili age.

In the archaeological site of Pompeii, epigraphs Tituli Picti applied on stone, such as Campanian ignimbrite in Oscan and Latin language, were surveyed by different authors. Although there are several publications concerning the building materials and artefacts of Pompeii, the scientific literature lacks of studies regarding the knowledge and conservation of such paints. The diagnostic and conservation project is aimed at determining the execution technique, as well as at defining the state of conservation of the Tituli Picti realized on the Campanian ignimbrite. In addition, the study will provide experimental data useful to suggest proper conservation procedures, mainly in terms of protective and consolidating products to be used. Results carried out by means of Optical Microscopy, Electron Probe Microanalysis, portable XRF and portable Raman techniques revealed that the epigraphs were applied on the stone surface, without any setting layer. Hematite-based red ochre was detected as pigment. On the contrary, it is still unclear if any substance was used to bind the pigment on the stone substrate. The subsequent stage of the project will include the reproduction of Tituli Picti in laboratory and the development of suitable conservation procedures to be tested in situ.

The molecular mechanism responsible for the thermosensitive behaviour exhibited by pH-responsive cyclodextrin-based hydrogels is explored here with the twofold aim of clarifying some basic aspects of H-bond interactions in hydrogel phases and contributing to a future engineering of cyclodextrin hydrogels for targeted delivery and release of bioactive agents. The degree of H-bond association of water molecules entrapped in the gel network and the extent of intermolecular interactions involving the hydrophobic/hydrophilic moieties of the polymer matrix are probed by UV Raman and IR experiments, in order to address the question of how these different and complementary aspects combine to determine the pH-dependent thermal activation exhibited by these hydrogels. Complementary vibrational spectroscopies are conveniently employed in this study with the aim of safely disentangling the spectral response arising from the two main components of the hydrogel systems, i.e. the polymer matrix and water solvent. The experimental evidence suggests that the dominant effects in the mechanism of solvation of cyclodextrin-based hydrogels are due to the changes occurring, upon increasing of temperature, in the hydrophobicity character of specific chemical moieties of the polymer, as triggered by pH variations. The achievements of this work corroborate the potentiality of the UV Raman scattering technique, in combination with more conventional IR experiments, to provide a "molecular view" of complex macroscopic phenomena exhibited in hydrogel phases.

Hydroxypropyl-β-cyclodextrin (HP-β-CyD) and sulfobutyl ether-β-cyclodextrin (SBE-β-CyD) were used to generate hydrophilic complexes of the poorly water-soluble drug testosterone propionate (TP). The inclusion complexes were obtained by freeze-drying, and then analyzed at both liquid and solid states. Phase solubility studies, performed according to the type-AL solubility diagrams of TP in presence of both CyDs, suggested the formation of water-soluble complexes at 1:1 molar ratio. These results were confirmed by continuous variation method (Job’s plot). Both CyDs increased water-solubility of TP 100-fold as compared to the native drug. The host-guest arrangement of CyD complexes in a water solution was further investigated by one- and two-dimensional NMR spectroscopy, highlighting the insertion of the tetracyclic ring of TP into the CyD cavity, and the interaction of the pending ester chain of drug with the primary hydroxyl groups of CyDs at the narrow end of the toroid structure. In solid phase, FTIR-ATR spectroscopy showed that the C O stretching mode of the TP vibrational spectrum changed if the complex between the drug and CyDs occurred. This change is temperature-dependent, and its evolution, accounted for by deconvolution procedures, provided the thermodynamic parameters explaining the mechanisms involved in the formation of inclusion complexes.

In the last decade, Raman spectroscopy has been used for routine investigation for gemmological purposes, being non-destructive and non-invasive. In addition, this technique grants short measurement times without any sample preparation. In this context, this work is focused on the spectroscopic characterization of different kinds of blue gems, including sapphires, by comparing the performance of a handheld Raman instrumentation along with a micro-Raman spectrometer, with the aim to provide gemmological certification and to get information on the provenance of the gems. The main goal of the present study is to identify imitation gems and to distinguish between natural and synthetic sapphire; in this latter case, micro-Raman measurements were fundamental for the characterization of the inclusions. Moreover, the chemical composition of blue gems has been obtained by portable XRF technique. The obtained data show that a portable Raman spectrometer can be recommended as a fast and easy instrument to discriminate sapphire from imitations. Copyright © 2014 John Wiley & Sons, Ltd.