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Allergic contact dermatitis involving the hands is a common occupational skin disease for hairdressers and the potent sensitizers p -phenylenediamine (PPD) and toluene-2,5-diamine (PTD) are associated with the development of occupational allergic contact dermatitis.The aim of the study was to analyze whether the use of the moderate sensitizer 2-methoxymethyl-PPD (ME-PPD) in professional hair dyes is a suitable tool to reduce the occupational contact allergy risk for hairdressers.Hand exposure of hairdressers (N = 11) to ME-PPD was analyzed under routine hair coloring conditions in commercial salons. By accounting for wet work and uneven hand exposure, the daily hand exposure was derived and compared with the occupational acceptable exposure level (AEL), that is, the sensitization induction threshold of ME-PPD adjusted for interindividual variability among workers.The daily hand exposure to ME-PPD was 1.6 μg/cm 2 , and the occupational AEL was 215 μg/cm 2 . The ratio of hand exposure to AEL was calculated as the margin of safety (MOS) against occupational sensitization. For ME-PPD, the MOS of 134 indicates a low likelihood of sensitization versus PPD and PTD with MOS values of 2.7 and 5.9, respectively.Our data predict that the use of ME-PPD in professional hair color products improves the protection of hairdressers against hair dye-related contact allergy versus the use of PPD and PTD.

Lighting is a critical component in a museum environment because, together with temperature, relative humidity and pollutants, it is one of the damaging factors able to produce long‐term, cumulative and irreversible photodegradation processes. To correctly preserve artworks, limiting illuminance and exposure is recommended, allowing on one side the preservation of the object, but on the other limiting the display of the object, especially for sensitive materials. The aim of this research was to develop, evaluate and compare a new lighting method for paintings and other cultural materials to improve the experience of the objects whilst reducing the risks from exposure. The idea is based on the use of selective chromatic light where the component of the spectrum absorbed by the materials is removed. This absorption is the principal cause of photodegradation. The proposed lighting system can be obtained by combining different types of projection systems together with filtering using an appropriate light source. Six methods of light projection have been compared for two mock-ups simulating real artworks with high and medium light sensitivity. The efficiency of illumination increased from 30% to 111% compared to standard lighting systems. Light stability tests were additionally performed, finding reduced colour changes compared to traditional lighting systems.

Microfading testing allows to evaluate the sensitivity to light of a specific artwork. Characterization of the illumination spot is important to determine its shape, dimensions, light distribution, and intensity in order to limit and account for possible damage. In this research the advantages and disadvantages of several methods used to determine the beam shape and intensity profiles are described with the aim of providing various options to microfading researchers interested in characterizing their irradiation spots. Conventional and imaging methods were employed and are compared in terms of their accuracy, cost, reliability, and technical features. Conventional methods consisted of an aperture technique using aluminium foil and four different materials namely stainless steel, silicon, muscovite, and Teflon used as sharp edges. The imaging methods consisted of digital photography of illumination spot, direct beam measurement using a CMOS camera, and direct beam measurement using a laser beam profiler. The results show that both conventional and imaging methods provide beam width measurements, which are in satisfactory agreement within experimental error. The two best methods were direct measurement of the beam using a CMOS camera and sharp-edge procedure. MFT illumination beam with a CMOS camera followed by a determination of the beam diameter using a direct method, more specifically one involving a sharp-edge technique.

This paper reports a comparative study on inks and pigments of nine old manuscripts belonging to the Algerian heritage. The manuscripts are held by Afniq n Ccix Lmuhib, one of the richest and best known private libraries from Kabylia region – Algeria. They date back from the 14th to the 19th century and treat disciplines ranging from astronomy to poetry. To identify the inks and pigments used by the scribes we applied several non-invasive techniques such as X-ray fluorescence, fiber optic reflectance and Raman spectroscopy. While XRF gives information about the elemental composition of pigments and inks, FORS and Raman analyses give the direct identification of the pigment. This synergy gives us a strong confidence in our identification even and allows to individuate critical cases on which deeper investigations should be done, as some results seems to contradict what is generally believed by art historians. In particular, we identified iron gall ink and ivory/bone black, while the black ink used in the Kabylia region is always reported to be made from burned sheep wool. Our work is the first case study that allows positive identification of inks and pigments used in Algerian manuscripts; interesting aspect, we could compare our findings are with manufacturing of pigments reported in a manuscript from the 17th century, held in the same library.

[Image: see text] (R)-ND-336—designated as compound (R)-5—is a highly selective inhibitor of matrix metalloproteinase (MMP)-9 with efficacy in accelerating diabetic wound healing in murine models. (R)-ND-336 belongs to the class of thiirane inhibitors of MMPs and it is currently undergoing Investigation New Drug (IND)-enabling studies. We investigated the in vitro metabolism of (R)-ND-336 using S9 fractions obtained from mice, rats, dogs, minipigs, monkeys, and humans in order to select the rodent and nonrodent species for toxicology studies. Three metabolites were observed. One metabolite, M3, was observed across all species. Metabolite M2 was found in rats, monkeys, and humans. Metabolite M1 was observed only in rats. The identities of the metabolites were suggested by liquid chromatography/tandem mass spectroscopy (LC/MS-MS) analyses, which were authenticated by comparison to synthetic samples. Metabolites M2 and M3 arise from oxidative deamination of (R)-ND-336 by monoamine oxidase to give the arylaldehyde as a transient (and unobserved) intermediate. Reductive metabolism of this aldehyde gives the alcohol metabolite M2, while further oxidative metabolism of the aldehyde produces the carboxylate metabolite M3. A minor route of metabolism, seen only in rats, is N-acetylation of (R)-ND-336 to give the acetamide M1. The metabolism of (R)-ND-336 is distinctly different from that of the prototype member of this thiirane class ((±)-1, lacking the 4-aminomethyl aryl substituent) which is metabolized primarily by oxidation α to the sulfone to lead to a benzenesulfinate metabolite. All three metabolites are poorer MMP-9 inhibitors, compared to (R)-ND-336 (MMP-9, K(i) = 19 nM): M3, MMP-9 IC(50) > 100 μM; M2, K(i) = 390 nM; and M1, IC(50) > 100 μM). The rat and the minipig were selected as the rodent and nonrodent species, respectively, for toxicology studies.

Coexistence between closely related species can lead to intense competition for resources. Stable isotope ratio analysis (SIRA) is a reliable tool to estimate the extent of species competition. We performed SIRA to assess niche partitioning among two syntopic species of Galápagos land iguanas: Conolophus subcristatus and the critically endangered C. marthae. We collected samples from 60 C. marthae and 58 C. subcristatus within an area of about 2 km2 on Wolf Volcano, Isabela Island, where C. marthae is endemic. We determined δ13C and δ15N ratios and described the isotopic niche of each species using corrected standard ellipse area (SEAc). We tested for differentiation between the isotopic niches, while controlling for sex, using bivariate linear models. Despite the extensive overlap of the isotopic niches, our results indicate the existence of niche partitioning mechanisms acting between species and sexes. Evaluating the effect of ecological variables, we found that body size and productivity at the capture points, plus further, undetermined spatial effects explain ca. 75% of the differences observed between species and sexes, providing evidence for differential microhabitat and food-items usage. Our study provides essential baselines for evaluating conservation actions for C. marthae, such as the potential translocation to a sanctuary area.

The recent conservative project of the imposing panel painting The Martyrdom of St. Catherine painted by Gaudenzio Ferrari (c.1477–1546) has been a precious opportunity to deepen the scientific knowledge about the execution technique—hitherto scarcely investigated—of one of the prominent exponents of the Lombard and Piemontese Renaissance. The conservative intervention had become necessary because of serious problems of the wooden support: cracks and deformations had caused lifts and color gaps. In addition, over time, many overpaints and varnishes had been altered, obscuring the brilliant original color tones of the painting. A diagnostic survey was planned based on a multidisciplinary approach consisting of a well-established protocol of non-invasive imaging (UVF, IRR, IRFC, RX) and point techniques (XRF, Vis-NIR FORS). The diagnostic analyses were performed in situ and carried out in the restoration laboratory of the Pinacoteca di Brera, an ad hoc space that allows visitors to see in real time restorers and scientists at work during the different stages of the conservation treatments. Analyses on micro-samples were further performed in laboratory by means of FTIR, Raman, SEM-EDX and GC-MS techniques. The research group together with restorers and art historians were able to deepen the understanding of the artwork from a technical, material and conservative point of view, making it possible a specific conservative intervention. Furthermore, the results of this research allowed shedding light on the mounting system of the wooden support and on the reconstruction of the original color palette used by the artist. An interesting point was the presence of pararealgar as an intentional use or as a result of the realgar alteration in some yellow areas. The huge dimensions of the painting (331 × 210 cm) forced the researchers to find unconventional technical solutions for a complete overview of the conservative condition. The results obtained from the precise recognition of the state of preservation of the varnish, the painting layers, the preparatory layers and the wooden support are here presented.

Reflectographic analyses applied on paintings can be performed using cameras equipped with different detectors with different abilities in detecting and visualizing underdrawings, repainting, restorations, and other nonvisible information. In this research, the results obtained through thermographic imaging followed by statistical imaging postprocessing methods have been compared with those obtained with traditional reflectographic methods in the short-wave infrared range. The comparison has been performed studying the thermal sequence after a single pulse of light with a different spectrum of ad hoc mock-ups. Results showed that for limited cases, signal-to-noise ratio seems to be more relevant in obtaining reliable images of underdrawings with respect to the effect of optical absorption of visible light by painting layers.

Since its ability to precisely characterized atherosclerotic plaque phenotypes, to tailor stent implantation, as well as to guide both complex percutaneous coronary interventions (PCI) and invasive diagnostic work-ups (e.g., spontaneous coronary dissections or myocardial infarction with non-obstructive arteries), the adoption of optical coherence tomography (OCT) was raised in the past decades in order to provide complementary information to the traditional angiography and to overcome its limitations. However, the impact of OCT on daily clinical practice is currently modest, firstly because of the lack of both standardized algorithms of PCI guidance and data from prospective clinical trials. Therefore, the aim of our narrative review is to provide a comprehensive overview of the basic OCT interpretation, to summarize the evidence supporting the OCT guidance procedures and applications, to discuss its current limitations, and to highlight the knowledge gaps that need to be filled with more robust evidence.

The use of non-invasive analytical techniques on cultural heritage objects usually faces the insurmountable limit of dealing with artworks subjected to more restorations. For painted surfaces, imaging techniques, such as infrared photography (NIR) and ultraviolet-induced visible fluorescence (UVIVF), allow to distinguish areas with different kind and period of interventions. This paper presents the application of such techniques on two wooden coffins of the 21st Dynasty with a complex restoration history, the analytical inspections deal with the issues occurring in the reconstruction of a fluorescence map that is influenced by on both the use of non-original pigments and the presence of protective varnishes. In uncontrolled laboratory conditions, the possibility to associate quantitatively and univocally the luminance recorded by the camera with a certain level of fluorescence can be very difficult. An algorithm has been developed to obtain a map with an evident relationship between fluorescence and diagnostic information. First, the pixels of the fluorescent areas presenting different reflectance in the visible image have been used to equalize the visible image. Then, the ratio of the UVIVF image to the equalized image has been calculated, highlighting the low and non-fluorescent areas. After the thresholding and the segmentation of the UVIVF image, the masks obtained have been overlaid on the NIR images to merge and to map the areas with supposed similar restoration materials. The results illustrated in this work are followed by a punctual spectroscopic campaign, where the information on the imaging analysis is linked to and completed by the study of the chemical compounds in the coffins.

Microfading testers have become widely accepted by the conservation science community for establishing and recommending appropriate lighting conditions that minimize damage to collections. These devices offer the opportunity of measuring the photostability of cultural heritage objects due to their optical setup, which allows to conduct and quantify accelerated photoaging over a spot of approximately 0.5 mm. Also, by using a high sensitivity photodetector it is possible to measure spectrocolorimetric change before it is perceived by the human eye. Although a considerable amount of testing is currently performed with these instruments, there are still safety concerns in terms of possible damage to the objects due to the use of a high intensity spot during testing. Nevertheless microfadeometry is widely considered a nondestructive technique. The advantages and disadvantages of several methods used to determine the beam shape and intensity profiles are described with the aim of providing various options to microfading researchers interested in characterizing their irradiation spots. Conventional and imaging methods were employed and are compared in terms of their accuracy, cost, reliability, and technical features. It has been found that both methods provide beam width measurements in satisfactory agreement within experimental error.

In healthy subjects, the transient perturbation of body part ownership is accompanied by regional skin temperature decrease. This observation leaves an open question about a possible body part-specific thermoregulatory response in pathological conditions, in which the sense of ownership over that body part is altered. For instance, Body Integrity Dysphoria (BID), a poorly understood neuropsychiatric disorder, is characterised by the non-acceptance of one or more of one's extremities. This unsettling feeling pervasively captures the individuals' attention towards the unwanted limb. Previous studies characterised BID in terms of absent ownership feeling with preserved ownership judgment. We explored for the first time whether this altered feeling is also associated with a specific thermoregulatory response. We recorded thermal image sequences of circumscribed regions of the limbs' skin in seven individuals with BID desiring to remove one leg while they were invited to focus their attention toward one particular limb (arm or leg). Their event-related thermoregulatory pattern was compared to a group of healthy matched controls. In individuals with BID but not in control persons, we found a bilateral decrease in leg temperature when focusing their attention on either the unwanted or accepted leg. The event-related thermoregulatory response for both upper limbs was similar between individuals with BID and healthy controls. Our results suggest that the alteration of the sense of body ownership in neuropsychiatric conditions such as BID may critically rest on specific event-related thermoregulatory patterns in response to modulation of attention to body parts.

Restoration and conservation procedures for historical musical instruments involve several issues, also connected with their frequent being played. One of the most delicate procedures for their preservation is the cleaning of surfaces from soil and dirt which have accumulated over the years. In fact, when external particles reach the surface, a fraction of them can deposit on it. Moreover, the contact with the player can generate chemical-physical changes, rapidly warming and wetting the surfaces through sweat deposition. This work focused on the cleaning methods of surfaces of bowed string musical instruments by a systematic and analytical approach. The selective cleaning procedure of varnished surfaces from grime and soil needs to be performed without compromising the original matter. Therefore, a dirty surface was reproduced on a set of varnished mock-ups and different water-based cleaning systems&mdash, generally used by restorers&mdash, were tested. The procedures were monitored in each step with several analytical methods: multispectral imaging (near-infrared (NIR), IRFC, visible imaging (VIS), UV-induced visible fluorescence), stereomicroscopy, XRF and FTIR spectroscopies allowed us to non-invasively outline the cleaning system efficacy. The results highlighted different levels of cleaning and, in some cases, it was possible to identify the best selectivity for the different procedures.

The project “Leonardesque Artists beyond the Visible” was planned on the 500th anniversary of the death of Leonardo da Vinci, with the occasion of an exhibition held in Milan in 2019, where more than twenty works made by Leonardesque masters have been put on display. Among them, five representative paintings made by his closest pupils were selected for a comprehensive and multidisciplinary project. Portable non-invasive imaging and spectroscopy techniques were applied to supply useful information to scholars but also to the wider public: description of the material composition of the pigments, of the preparation and of the binders, existence or absence of underdrawing, and identification of the painters’ technique and style. Particular attention was paid also to the image processing techniques, mostly for hyperspectral and radiographic data, to get the most from both innovative and traditional techniques. Results highlighted for each author a peculiar painting technique showing hidden features such as pentimenti and the panel preparation methods, pigments, binders and varnishes.

Pulsed thermography was exploited to identify the presence of glass defects in order to get an indication of the conservation status of archaeological glass. Indeed, the process of degradation in artifacts subjected to centuries of burial can be of great relevance. More specifically, we evaluated the potential of pulsed thermography to map the presence of flakes in archaeological glass. This was achieved by comparing different heating setups and signal-processing algorithms. Tests were carried out previously on glass mockups with surface defects and then on archaeological artifacts.

In the recent years electro-osmosis drying devices applied to walls in both modern and historic masonry has become one of the leading innovative techniques to prevent damages caused by capillary rising water in building materials. Since the scientific community is raising many doubts on these techniques, the authors aim to propose a fast, simple, noninvasive and economic method to evaluate the dehumidification process specimens of the most used building materials. The paper presents a procedure to monitor water content in different specimens of the most used building materials (e.g. brick, mortar and plaster) and verify any kind of possible effect of electro-osmosis on water diffusion, above all drying kinetic. The procedure is based on the measure of water content and drying behaviour with and without the application of electrostatic fields with the traditional gravimetric method, infrared thermography and optical reflectance in the 940–980 nm with a high sensitivity avalanche photodiode. This allowed us to visualize the surface water content gradient of different building materials. Using different voltage values between tow electrodes coupled with the material under examination, we observed no variation in water distribution inside the material nor any difference in evaporation phenomena. For strong electric field values (V > 150 V/m), compared to those normally used in electro-osmosis dehumidification, we measured mainly the heating caused by the Joule effect due to the intrinsic ion's distribution inside the material.

The Royal Museums of Art and History of Brussels holds six coffins of the 21st Dynasty coming from a single discovery, the Second Cachette of Deir el-Bahari (Bab el-Gasus) (L. Delvaux & I. Therasse, Sarcophages. Sous les etoiles de Nout, Bruxelles 2015, p. 83–111). Since their discovery in 1891, their rich decorations have been subjected to deep manipulations during the years. In 2014, six coffins and four mummy-covers, the entire collection of the 21st Dynasty, were entrusted to the European Institute of Restoration for their diagnosis and restoration. In 2015, one compete coffin (composed by the external coffin, the internal one and the mummy cover) were the subject of a first targeted diagnostic campaign at the European Institute of Restoration laboratories. On this occasion, non-invasive in situ analyses have been performed on more than one hundred measuring points of the complete object, considering the five decorated parts (the two wooden anthropoid coffins composed by lid and base and the mummy-cover) showing both different technical features and pictorial materials. After a preliminary phase of analysis by imaging techniques such as Infrared Reflectography and Visible Fluorescence induced by UV, the pigments and binders were examined exploiting the synergy between four complementary techniques, namely EDXRF (energy dispersive X-ray fluorescence), FORS (fibre optics reflectance spectroscopy), reflection FTIR (Fourier transform infrared spectroscopy) and micro-Raman spectroscopy. The application of techniques with different penetration depths on more than one hundred points allowed to detect the stratigraphic sequences without sampling, opening to the interesting application to off-limits masterpieces. Based on imaging techniques, the painted surfaces showed areas with different features: dark areas with no UV fluorescence and low reflectance in IR, bright UV fluorescence and high IR reflectance (wavelength > 700 nm) and low-intensity UV fluorescence again with high reflectance in the infrared region. Such zones can be linked to the presence or absence of marker chemical elements (for instance Ba or Ti) or compounds that give hints about the presence and the period of the restorations. In these areas, an overlapping of a modern layer on the ancient and original one is the most probable current status of the pictorial stratigraphy. Original identified pigments include Egyptian blue, copper-based green, calcium carbonate and Red Ochre on an underlying Orpiment yellow layer. In the areas considered as already restored in the past on the bases of the analytical results, we find Azurite, Prussian blue, Egyptian Blue, Vermillion, Red Ochre, Chrome Red, Chrome Green, copper-based green, Zinc Yellow and Lead White. A layer composed of a natural resin was also detected by in-situ FTIR measurements; the resin could be more precisely identified as mastic by laboratory analyses.

Facial asymmetry is considered a marker of psychological, emotional and physiological distress, while anxiety is a behavioural, psychological and physiological response to a threat to well-being. Since individuals respond to anxiety with specific patterns (e.g., muscular tension), it is reasonable to hypothesize that anxiety could contribute to facial tension and therefore facial asymmetry. Instead, since facial asymmetry is perceived as "unpleasant" from peers, its presence may be a hindrance to social adaptation contributing to generate anxiety. In this study, we investigated whether resting facial asymmetry and anxiety are associated in young population. Full frontal facial photographs of 56 Caucasian males were taken in resting state to obtain indices of asymmetry in six facial landmarks. Anxiety status was assessed using the State-Trait Anxiety Inventory (STAI-Y). Analysis of the face showed that asymmetry and laterality of specific facial landmarks were associated with anxiety. State anxiety was associated with eyebrow and lateral angle of the eye, while trait anxiety was associated with eyebrow and lateral angle of the mouth. Moreover, as compared with contralateral landmarks, the left landmarks were lifted/expanded in subjects with elevated trait/state anxiety, whereas the right landmarks were lifted/expanded in subjects with low-trait/state anxiety.

Studies on the optical absorbance spectra of Fricke xylenol orange gel dosimeters were performed, in the wavelength range from 300 nm to 800 nm, in order to highlight some particular characteristics that can affect the achievable precision. The spectra are different mainly due to the different types of xylenol orange that was used and to a lower extent due to the different gelling agents (agarose or gelatine). The characteristic of variation of absorbance spectra versus dose, however, are similar in the various cases and can explain some peculiarities, as apparent effects of dose threshold. Changes of spectral shapes appear over the time after irradiation. Magnetic resonance measurements performed at various times after irradiation only reveal the slow changes due to the auto-oxidation effect, proving therefore that the modality of chelation of ferric ions by xylenol orange can affect the observed changes in the optical absorbance spectra.

Non-invasive, portable analytical techniques are becoming increasingly widespread for the study and conservation in the field of cultural heritage, proving that a good data handling, supported by a deep knowledge of the techniques themselves, and the right synergy can give surprisingly substantial results when using portable but reliable instrumentation. In this work, pigment characterization was carried out on 21 Leonardesque paintings applying in situ X-ray fluorescence (XRF) and fiber optic reflection spectroscopy (FORS) analyses. In-depth data evaluation allowed to get information on the color palette and the painting technique of the different artists and workshops . Particular attention was paid to green pigments (for which a deeper study of possible pigments and alterations was performed with FORS analyses), flesh tones (for which a comparison with available data from cross-sections was made), and ground preparation.

The most common method to derive a temperature value from a thermal image in humans is the calculation of the average of the temperature values of all the pixels confined within a demarcated boundary defined region of interest (ROI). Such summary measure of skin temperature is denoted as Troi in this study. Recently, an alternative method for the derivation of skin temperature from the thermal image has been developed. Such novel method (denoted as Tmax) is based on an automated (software-driven) selection of the warmest pixels within the ROI. Troi and Tmax have been compared under basal, steady-state conditions, resulting very well correlated and characterized by a bias of approximately 1 °C (Tmax > Troi). Aim of this study was to investigate the relationship between Tmax and Troi under the nonsteady-state conditions induced by physical exercise. Thermal images of quadriceps of 13 subjects performing a squat exercise were recorded for 120 s before (basal steady state) and for 480 s after the initiation of the exercise (nonsteady state). The thermal images were then analysed to extract Troi and Tmax. Troi and Tmax changed almost in parallel during the nonstead -state. At a closer inspection, it was found that during the nonsteady state the bias between the two methods slightly increased (from 0.7 to 1.1 °C) and the degree of association between them slightly decreased (from Pearson’s r = 0.96 to 0.83). Troi and Tmax had different relationships with the skin temperature histogram. Whereas Tmax was the mean, which could be interpreted as the centre of gravity of the histogram, Tmax was related with the extreme upper tail of the histogram. During the nonsteady state, the histogram increased its spread and became slightly more asymmetric. As a result, Troi deviated a little from the 50th percentile, while Tmax remained constantly higher than the 95th percentile. Despite their differences, Troi and Tmax showed a substantial agreement in assessing the changes in skin temperature following physical exercise. Further studies are needed to clarify the relationship existing among Tmax, Troi and cutaneous blood flow during physical exercise.

Infrared reflectography is an imaging technique used to visualize the underdrawings of ancient paintings; it relies on the fact that most pigment layers are quite transparent to infrared radiation in the spectral band between 0.8 μm and 2.5 μm. InGaAs sensor cameras are nowadays the most used devices to visualize the underdrawings but due to the small size of the detectors, these cameras are usually mounted on scanning systems to record high resolution reflectograms. This work describes a portable scanning system prototype based on a peculiar spherical scanning system built through a light weight and low cost motorized head. The motorized head was built with the purpose of allowing the refocusing adjustment needed to compensate the variable camera-painting distance during the rotation of the camera. The prototype has been tested first in laboratory and then in-situ for the Giotto panel “God the Father with Angels” with a 256 pixel per inch resolution. The system performance is comparable with that of other reflectographic devices with the advantage of extending the scanned area up to 1 m × 1 m, with a 40 min scanning time. The present configuration can be easily modified to increase the resolution up to 560 pixels per inch or to extend the scanned area up to 2 m × 2 m.

In the context of paintings characterization, X-Ray Fluorescence (XRF) combined with Fibre Optics Reflectance Spectroscopy (FORS) is a well-known methodology. The latter allows to classify the pigments constituting the external layers (few microns) of the painting while the former provides the fingerprint of the main chemical elements present in almost all layers (tens of microns) of the sample. The synergetic application of XRF and FORS is a key turn for non-invasive scientific analysis of works of art since it exhaustively describes the pigments employed by the masters and supplies a first insight into their distribution on the panels. In this scenario, Optical Microscopy (OM) applied directly on the painting surface, without any type of sampling, is traditionally deemed as a descriptive tool for showing microscopic features such as craquelure, brushstrokes or painting material distribution. It can be eventually expendable as a qualitative help during the discussion of spectroscopic data, but not considered fundamental. Nonetheless, the application of image processing protocols can make OM a concrete support for the characterization of paintings. In this work a new image analysis strategy has been introduced, its potential has been demonstrated studying different flesh tones from the panel “The Holy Family with St. Anne and the young St. John” by Bernardino Luini (Pinacoteca Ambrosiana Collection of Milan) and, finally, it has been discussed how OM could quantitatively complete XRF and FORS analysis. The results show that optical microscopy, other than provide a glance of the investigated surface spots, effectively integrates the description given by the spectroscopic techniques and, properly managed, can be a useful resource for solving ambiguous cases.

Low intensity resistance training with slow movement and tonic force generation has been shown to create blood flow restriction within muscles that may affect thermoregulation through the skin. We aimed to investigate the influence of two speeds of exercise execution on skin temperature dynamics using infrared thermography. Thirteen active males performed randomly two sessions of squat exercise (normal speed, 1s eccentric/1s concentric phase, 1s; slow speed, 5s eccentric/5s concentric phase, 5s), using ~50% of 1 maximal repetition. Thermal images of ST above muscles quadriceps were recorded at a rate of 0.05Hz before the exercise (to determine basal ST) and for 480s following the initiation of the exercise (to determine the nonsteady-state time course of ST). Results showed that ST changed more slowly during the 5s exercise (p=0.002), whereas the delta (with respect to basal) excursions were similar for the two exercises (p>0.05). In summary, our data provided a detailed nonsteady-state portrait of ST changes following squat exercises executed at two different speeds. These results lay the basis for further investigations entailing the joint use of infrared thermography and Doppler flowmetry to study the events taking place both at the skin and the muscle level during exercises executed at slow speed.

Monitoring surface moisture content (MC)is a required activity and a topic of current interest in conservation studies. The present work examines the possibility of using the spectral reflectance factor at 970 nm (Rλ970) for the noninvasive quantitative determination of surface MC in building materials. Indeed, the quantification of surface liquid water by optical measurements is poorly exploited on porous media despite it is well documented in many remote sensing technologies such as in agriculture, soil science and some industrial application. The measurements apparatus is tested in a laboratory experiment on different specimens of building materials. The custom-made detector is a Si-core Avalanche Photo Diode (APD) operating in Geiger mode which satisfy the requirements of non-invasiveness and ease of use with the additional opportunity for developing economic, automated and reliable solutions. The results obtained for six representative cultural heritage building materials clearly show the dependence between Rλ970 and surface SMC: Rλ970 increases as surface MC decrease following the drying process of an unsaturated porous matrix i.e. evaporative flux supported by capillary pumping. This work reports the possibility to use the reflectance value at a specific wavelength for an alternative and non-invasive measurements of MC.

Purpose of this study is to test if possible effects of gelation temperature and pH on the cross-linking process between poly(vinyl alcohol) (PVA) and glutaraldehyde (GTA), have consequences on the dosimetric properties of PVA-GTA Xylenol Orange Fricke gel dosimeters. Therefore, dose-response curves and Fe3+ diffusion rate of PVA-GTA Fricke gel dosimeters prepared using different sulfuric acid concentrations and different gelation temperature were investigated by optical absorbance measurements. The results demonstrated that the sulfuric acid concentration determines both the dose sensitivity of the PVA-GTA Xylenol Orange Fricke gel dosimeters and the interval of linearity of the dose-response curve. Although the effects of gelation temperature and sulfuric acid concentration on the PVA-GTA cross-linking process may occur, no significant consequences on diffusion properties of PVA polymer network were observed. Indeed, Fe3+ diffusion rates in all investigated samples were very similar, and less than half of those achievable in Fricke gel dosimeters prepared with natural gel matrices like gelatin and agarose.

God the Father with Angels (about 1330, tempera on panel) by Giotto is the Gable of the altarpiece of Baroncelli Chapel in the church of Santa Croce in Florence. Very little is known about its history since the separation from the so-called Baroncelli Polyptych. Now at the San Diego Museum of Art, the Gable had never been studied by means of scientific methods before our team took the opportunity to during the exhibition “Giotto, l’Italia”, held in Milan. Exploiting the integration of different knowledge, technologies and resources of our team, we were able to provide data for understanding the organizational model of Giotto's workshop performing non-invasive analyses with portable instruments during closing hours of exhibition (four diagnostic campaigns, six hours of work/campaign, no interruption of the exhibition). The achieved results confirm the painting technique based on different layers of pigments, a technique already used by Giotto. Combining the effectiveness of scanning MA-XRF with the responsive of IR reflectography and IR false colour, we moved step by step toward the discovery of Giotto's palette for the flesh tones in God the Father with Angels. FORS and XRF single point analyses were performed on some selected areas too. The IR reflectography results support the hypothesis of a detailed underdrawing with both thin and flat brushstrokes. By applying image-processing algorithms to the collected reflectograms, we obtained quantitative objective measures supporting the hypothesis that a guide could have been used in the realization of human figures; this means the use of sketches for the face of “God the Father” and for the faces of angels.

The process of degradation of archaeological glass subjected to centuries of burial can be of great relevance: typical consequence of degradation in the original vitreous material is rainbow-like iridescence due to chemical alteration of surface layers, salts formation and ion migration. The research presented in this paper is focused on the study of a collection of Roman glass (I - II century A.D.) held by the Museo Civico Etnografico Archeologico Fanchini of Oleggio, Italy. Chemical characterization (namely flux, chromophores and opacifiers determination) has been performed by a combination of X-Ray Fluorescence (XRF) and Fibre Optics Reflectance Spectroscopy (FORS) in the UV–Vis-NIR region. Conservation conditions have been studied and degraded areas have been mapped through Infrared thermography (IRT). IRT is a non-invasive method typically used to measure the apparent temperature of objects and represent it as pseudo-colour images. In the present work, we demonstrate the feasibility of IRT for identifying and mapping glass substrate defects due to ageing of glass, assuming that they may be considered as thermal anomalies. Thermogram sequences have been processed by high order statistical analysis, which is particularly suitable since it is based on automated processes where the output is a single representative image. The use of a thermal camera allows furthermore to perform remote analysis in areas hardly reachable in a fast and effective way.

A promising approach in oncology consists in combining Radiation Therapy (RT) with Magnetic Fluid Hyperthermia (MFH). Modern day RT takes advantage by imaging techniques able to provide information about the correct patient set-up, target position and movement during the treatments. For these purposes, gold fiducial markers, implanted into the tumors, or in their proximity, are used in the so-called Image-Guided Radiation Therapy (IGRT). In this study, hyperthermia produced by different gold fiducial markers under the application of an alternating magnetic field in the typical conditions used in Magnetic Fluid Hyperthermia (MFH) clinical trials was investigated. The temperature increase of different types of gold fiducial markers and of tissue mimicking hydrogel phantoms containing the fiducials were measured during the magnetic stimulation by means of a high-resolution thermal camera and a fiber optic temperature sensor. The results demonstrated that, within few tens of seconds after the start of the magnetic stimulation, the gold fiducial markers might reach temperatures higher than 70 °C. Local increases of the hydrogel temperature to values higher than 45 °C were also measured. These evidences highlight the need to evaluate carefully the presence and location of gold fiducial markers in patients undergoing combined IGRT and MFH treatments in order to prevent any thermal ablation of health tissues surrounding the markers.

International audience

Imaging techniques are commonly used to improve the legibility of text in ancient or degraded documents. Infrared reflectography is one of the best methods for examining documents written in a carbon-based ink since the contrast between the ink and the support is usually much greater in that band. In these cases, for archival and study purposes, the visible and the corresponding infrared images are usually shown next to one another. In other cases, like e.g. papyri, this separation between text and background is not easily achievable, and therefore, a more sophisticated elaboration is needed. Moreover, in these cases, the background is a relevant source of information on the original document, and thus its integration with the extracted text could represent an effective solution for scholars. In this paper, we present a new method to improve the legibility of the text in visible light reflectance images without altering the appearance of the support. The method is based on the fusion of the text extracted from the infrared image with the visible image. The contrast of the text in the infrared image is first enhanced with the Automatic Color Equalization algorithm, a perceptual-based enhancement technique, and then extracted with a thresholding process. The proposed method allows to visualize different information (text, background, alterations, etc.) on a single image, and can be also used for an efficient archival approach.

The Giotto’s masterpiece God the Father with Angels, never investigated till now, was studied by our team of local researchers, involved in application of scientific methods for cultural heritage since many years. Exploiting the integration of different knowledges, technologies and resources of our team, we were able to provide data to understand the painting technique, the pigment used and the underdrawing of this Giotto’s painting. We performed the following non-invasive analyses: Macro-XRF scanning (MA-XRF), Fiber optic reflectance spectroscopy (FORS), high resolution IR scanning reflectography, infrared false color (IRFC). Only portable instrumentations were used, with operating times compatible with the opening hours of exhibition. In particular, the analytical campaign was the opportunity to test the portable IR scanning prototype based on a peculiar spherical scanning system characterized by light weight and low cost motorized head. The analytical results revealed a painting technique already used by Giotto and based on different superimposed pigment layers. By combining the effectiveness of scanning portable-XRF (pXRF) with the responsive of image spectroscopic analysis, we move step by step toward the discovery of Giotto’s palette, with particular attention to the flesh tones in God the Father with Angels. The imaging data support the hypothesis of a detailed underlying sketch that includes also a drawing characterized by larger brush signs; the use of patrones for the face of “God” was supposed thanks to comparison with other Giotto masterpieces.

The response of Fricke xylenol orange gelatin dosimeter has been studied to investigate the possibility of achieving a calibration method based on a preirradiation procedure. With this aim, different preirradiation parameters have been tested, and the system response to subsequent irradiations has been investigated. Both Fricke gel layers and cuvettes were considered, and no dependence on shape and wall material was observed. An increase of the system response was observed, depending on the total absorbed dose and not on the number of subsequent irradiations performed, as evidenced by the changes of the absorption spectra shapes. Moreover, different calibration curves, and consequently different sensitivities, were obtained with different preirradiation parameters. In order to propose a calibration procedure, further studies are of fundamental importance to deeper comprehending the influence of preirradiation parameters on the system sensitivity and response. In particular, a systematic analysis of the whole absorption spectra has proved to be central.

Scintillating optical fibres have shown interesting results for ionizing radiation monitoring. Since they may enable a remote, punctual and real-time dose assessment, their application in medical dosimetry is very promising. This work aims to summarize some recent progresses in the development and characterization of rare-earth doped silica optical fibres. The radioluminescent and dosimetric properties of Ce, Eu and Yb-doped fibres are presented and the advantages and challenges in the use of these sensors for radiation therapy dosimetry are discussed. For such application, an effective approach to deal with the stem effect, i.e. the spurious luminescent signal originated in the light guide as a consequence of its exposition to ionizing radiations (i.e. Cerenkov light and intrinsic fluorescence) must be considered. The stem effect mainly occurs in the UV-VIS region. We demonstrated that the use of a dopant emitting in the near infrared, like Yb, is suitable for an optical discrimination of the dosimetric signal. Indeed, through a characterization of the dosimetric properties of Yb-doped fibres in conjunction with an optical filter and an avalanche detector, we proved that the drawback due to the stem effect does not impair the system response even in the most challenging irradiation geometries, attesting to the robustness of the device in complex dosimetric scenarios.