Advanced Microspatially Offset Raman Spectroscopy for Noninvasive Imaging of Concealed Texts and Figures Using Raman Signal, Fluorescence Emission, and Overall Spectral Intensity.

This study explores the possibility of using microspatially offset Raman spectroscopy (micro-SORS) imaging to reconstruct noninvasively letters and figures hidden by opaque layers. Micro-SORS experiments were conducted on mockup samples that mimic real situations encountered in the cultural heritage field, such as sealed letters with inaccessible text and original documents. Subsurface images were obtained using both the characteristic Raman bands of the hidden compounds and their different optical properties from the remaining matrix. In the latter case, contrast obtained through observing a difference in the overall spectral intensity and fluorescence profile rather than any specific Raman bands were used to track the images within the hidden layer. This approach opens new prospects for the use of micro-SORS in heritage science, with applications in the field that include the study of objects covered by opaque overlayers not only through their Raman signatures but also through differences in their optical properties (e.g., fluorescence emission, absorption).

Synchrotron radiation X-ray diffraction computed tomography (XRDCT): a new tool in cultural heritage and stone conservation for 3D non-destructive probing and phase analysis of inorganic re-treatments.

The issue of preserving carbonatic stones of cultural heritage (CH) restored in the past that have undergone new decay phenomena is strongly emerging and conservation science has not yet found a reliable solution. In this paper, we propose the application of synchrotron radiation X-ray diffraction computed tomography (XRDCT) to explore the effects of using inorganic-mineral products (ammonium oxalate; ammonium phosphate) in sequence as a novel, compatible and effective re-treatment approach to consolidate decayed carbonatic stones already treated with inorganic-mineral treatments. High-quality XRDCT datasets were used to qualitatively/quantitatively investigate and 3D localize the complex mixture of crystalline phases formed after the conservation re-treatments within a porous carbonatic stone substrate. The XRDCT reconstruction images and the structural refinements of XRD patterns with the Rietveld methods showed that the phase composition of reaction products, their volume distribution, and weight fraction vary as a function of the treatment sequence and penetration depth. The high potential of XRDCT allows (i) assessment of peculiar trends of each treatment/treatment sequence; (ii) exploration of the reaction steps of the sequential treatments and (iii) demonstration of the consolidating effect of inorganic re-treatments, non-destructively and at the micron scale. Above all, our study (i) provides new analytical tools to support the conservation choices, (ii) showcases new analytical possibilities for XRDCT in conservation science, including in investigations of CH materials and decay processes, and (iii) opens up new perspectives in analytical chemistry and material characterisation for the non-destructive and non-invasive analysis of reactions within heterogeneous polycrystalline systems.

Non-destructive distinction between geogenic and anthropogenic calcite by Raman spectroscopy combined with machine learning workflow.

Here, we demonstrate, for the first time, the possibility of distinguishing between geogenic and anthropogenic calcite in a non-destructive and effective way. Geogenic calcite derives from natural sedimentary and metamorphic rocks whereas anthropogenic calcite is formed artificially due to the carbonation process in mortars and plaster lime binders. Currently, their distinction is a major unaddressed issue although it is crucial across several fields such as 14C dating of historical mortars to avoid contamination with carbonate aggregates, investigating the origins of pigments, and studying the origins of sediments, to name a few. In this paper, we address this unmet need combining high-resolution micro-Raman spectroscopy with data mining and machine learning methods. This approach provides an effective means of obtaining robust and representative Raman datasets from which samples' origins can be effectively deduced; moreover, a distinction between sedimentary and metamorphic calcite has been also highlighted. The samples, chemically identical, exhibit systematic and reliable differences in Raman band positions, band shape and intensity, which are likely related to the degree of structural order and polarization effects.

Synchrotron X-ray diffraction computed tomography to non-destructively study inorganic treatments for stone conservation.

The characterization of consolidating products formed by conservation treatments within Cultural Heritage (CH) materials is a burning issue and an analytical challenge, as non-destructive approaches, phase analysis, and volume distribution analysis are simultaneously required. This paper proposes the use of synchrotron X-ray diffraction computed tomography (XRDCT) to non-destructively study diammonium hydrogen phosphate (DAP) consolidating treatments for stone conservation. The mineralogical composition and localization of crystalline phases formed in a complex mixture have been explored and spatially resolved. The coexistence of hydroxyapatite and octacalcium phosphate has been finally demonstrated. The image analysis highlights the 3D distribution of calcium phosphates, their arrangement in a binding network down to the voxel scale, and their consolidating action. Above all, this study demonstrates the feasibility and high potential of XRDCT to investigate the interactions of conservation treatments with CH stone materials, and opens new analytical perspectives for XRDCT in conservation science and materials science.

Quantification of hand functional recovery in spinal cord injury patients.

STUDY DESIGN: A prospective cohort study. OBJECTIVES: To examine the use of a circle-tracing task in quantifying hand functional recovery in cervical spinal cord injury patients. METHODS: Ten cervical spinal cord injury (SCI) patients and 10 healthy age-matched controls performed a circle-tracing task, using a computerized tablet at the beginning of the study and after 4 weeks. Data relative to performance accuracy as well as pen pressure throughout the performances were collected, and clinical assessment for all patients was performed at the beginning and at the end of the study. RESULTS: Significant differences were found in pen pressure profiles in the SCI patients between the initial assessment and after 4 weeks of assessment. SCI patients, when compared with controls, apply less pressure during the execution, though no significant differences were found for the other parameters. Examination of pen pressure profiles of both controls and SCI patients reveals that, in addition to the lower pressure registered, SCI patients present a more oscillating pressure profile which is direction-dependent. No significant correlations were found between clinical assessments and pen pressure, both within the initial assessment as well as after 4 weeks. CONCLUSIONS: This study emphasizes the potential of simple computerized means for quantifying upper limb functions in SCI patients. These results of this study could be helpful for both highlighting specific functional deficits in patients as well tailoring specific interventions.

Non-destructive Monitoring of Dye Depth Profile in Mesoporous TiO2 Electrodes of Solar Cells with Micro-SORS.

The dye distribution within a photo-electrode is a key parameter in determining the performances of dye-sensitized photon-to-electron conversion devices, such as dye-sensitized solar cells (DSSCs). A traditional, depth profiling investigation by destructive means including cross-sectional sampling is unsuitable for large quality control applications in manufacturing processes. Therefore, a non-destructive monitoring of the dye depth profile is required, which is the first step toward a non-destructive evaluation of the internal degradation of the device in the field. Here, we present a conceptual demonstration of the ability to monitor the dye depth profile within the light active layer of DSSCs by non-destructive means with high chemical specificity using a recently developed non-destructive/non-invasive Raman method, micro-spatially offset Raman spectroscopy (micro-SORS). Micro-SORS is able to probe through turbid materials, providing the molecular identification of compounds located under the surface, without the need of resorting to a cross-sectional analysis. The study was performed on the photo-electrode of DSSCs. This represents the first demonstration of the micro-SORS concept in the solar cell area as well as, more generally, the application of micro-SORS to the thinnest layer to date. A sample set has been prepared with varying concentrations of the dye and the thickness of the matrix consisting of a titanium dioxide layer. The results showed that micro-SORS can unequivocally discriminate between the homogeneous and inhomogeneous dye depth profiles. Moreover, micro-SORS outcomes have been compared with the results obtained with destructive time-of-flight secondary ion mass spectrometry measurements. The results of the two techniques are in good agreement, confirming the reliability of micro-SORS analysis. Therefore, this study is expected to pave the way for establishing a wider and more effective monitoring capability in this important field.

Enriching the knowledge of Ostia Antica painted fragments: a multi-methodological approach.

This paper presents the study of selected painted fragments from different contexts of Ostia Antica city, dating between 2nd century BCE and the end of the 1st century CE. The aim is to identify the raw materials used and to understand the execution techniques through a non-invasive protocol including techniques based either on multiband imaging (Visible-VIS, Ultraviolet induced Luminescence - UVL and Visible Induced Luminescence - VIL) and single spot analyses (Fiber Optic Reflectance Spectroscopy- FORS and portable X-Ray Fluorescence spectrometry - XRF). The most representative and interesting fragments were sampled for further studies with laboratory techniques such as optical microscopy (OM) and electron microscopy (SEM), Fourier Transform Infrared and micro-Raman Spectroscopies (FT-IR and µRaman). The extensive use of non-invasive techniques, even working on fragments, is proved to be the most robust and effective approach enabling the analysis of a high number of areas, dramatically increasing the statistical meaning of the collected data. The elaboration of such a huge number of data allows highlighting differences and similarities, thus achieving a more realistic overview of the materials composition and addressing the sampling to the more significant and complex areas.

Evaluation of the Psychometric Properties of the Scale A-ONE: An Italian Cross-Sectional Study.

PURPOSE: This study is aimed at validating the A-ONE scale in an Italian population with Central Nervous System (CNS) dysfunction. Material and Methods. Between May and November 2018, people aged between 60 and 90 with CNS dysfunction were recruited in a hospital in Rome, Italy. Patients were observed and evaluated during the activities of daily living. Internal consistency and reliability were evaluated with Cronbach's coefficient alpha and intraclass correlation coefficient, respectively. As measured with Pearson's correlation coefficient, the validity was examined comparing results of the A-ONE with the Barthel index. Responsiveness was evaluated 30 days after the first administration. RESULTS: A total of 70 people having a diagnosis of neurological disorders were evaluated. The internal consistency showed Cronbach's coefficient alpha ranging from 0.634 to 0.959. The measurement of reliability varied from 0.984 to 0.997 for intrarater and from 0.979 to 0.998 for interrater. Pearson's correlation coefficient between the A-ONE and the Barthel index and the responsiveness showed statistically significant values (p < 0.01). CONCLUSIONS: The present study provides preliminary evidence of reliability, validity, and responsiveness of the A-ONE when using elderly people with CNS dysfunction.

Sub-Surface Molecular Analysis and Imaging in Turbid Media Using Time-Gated Raman Spectral Multiplexing.

Obtaining molecular information deeper within optically turbid samples is valuable in many applications. However, in many cases this is challenging, in particular when the sample elicits strong laser-induced fluorescence emission. Here, we investigated the use of time-gated and micro-spatially offset Raman spectroscopy (micro-SORS) based on spectral multiplexing detection to obtain sub-surface molecular analysis and imaging for both fluorescing and non-fluorescing samples. The multiplexed spectral detection achieved with a digital micromirror device (DMD) allowed fast acquisition of the time-gated signals to enable three-dimensional Raman mapping (raster scanning in the lateral x,y plane and using time-of-flight calibration for the axial z-direction). Sub-millimeter resolution molecular depth mapping was achieved with dwell times on the order of seconds per pixel. To suppress fluorescence backgrounds and enhance Raman bands, time-gated Raman spectroscopy was combined with micro-SORS to recover Raman signals of red pigments placed behind a layer of optically turbid material. Using a defocusing micro-SORS approach, both fluorescence and Raman signals from the surface layers were further suppressed, which enhanced the Raman signals from the deeper sublayers containing the pigment. These results demonstrate that time-gated Raman spectroscopy based on spectral multiplexed detection, and in combination with micro-SORS, is a powerful technique for sub-surface molecular analysis and imaging, which may find practical applications in medical imaging, cultural heritage, forensics, and industry.

Synchrotron radiation µ X-ray diffraction in transmission geometry for investigating the penetration depth of conservation treatments on cultural heritage stone materials.

The assessment of the penetration depth of conservation treatments applied to cultural heritage stone materials is a burning issue in conservation science. Several analytical approaches have been proposed but, at present, many of them are not fully exhaustive to define in a direct way the composition and location of the conservation products formed after inorganic mineral treatments. Here, we explored, for the first time, the analytical capability of synchrotron radiation µ X-ray diffraction in transmission geometry (SR-µTXRD) for the study of the crystal chemistry and penetration depth of the consolidating phases formed after the application of diammonium hydrogen phosphate (DAP) treatments on a porous carbonatic stone (Noto limestone). The SR-µTXRD approach provided unambiguous information on the nature of the newly formed calcium phosphates (hydroxyapatite, HAP, and octacalcium phosphate, OCP) with depth, supplying important indications of the diffusion mechanism and the reactivity of the substrate. Qualitative and semi-quantitative data were obtained at the microscale with a non-destructive protocol and an outstanding signal-to-noise ratio. The SR-µTXRD approach opens a new analytical scenario for the investigation of a wide range of cultural heritage materials, including natural and artificial stone materials, painted stratigraphies, metals, glasses and their decay products. Furthermore, it can potentially be used to characterize the penetration depth of a phase "A" (or more crystalline phases) in a matrix "B" also beyond the cultural heritage field, demonstrating the potential wide impact of the study.

Umbilical cord management strategies at cesarean section.

AIM: To evaluate the effect of different strategies to improve placental transfusion in cesarean section (CS). METHODS: Retrospective analysis of all singleton term pregnancies that underwent CS over 6 months. Delayed umbilical cord clamping (dUCC) was defined as one done at least 60 s after birth. Umbilical cord milking (UCM) was an option when waiting 60 s was deemed unsafe. The two strategies were compared against early (<60 s) umbilical cord clamping (eUCC) without milking. Neonatal hematocrit (Hct) at 48 h was the main outcome variable. RESULTS: Of the 223 CS in the cohort, 100 were performed in labor and 123 were elective. dUCC was performed in 137, eUCC without milking in 53 and UCM in 33 cases. Neonatal Hct was higher in CS carried out in labor versus in elective CS (59.76% ± 6.17 vs 56.91% ± 5.95, P = 0.001). At multivariate analysis, CS performed in labor (coefficient [coeff.] 3.44, confidence interval [CI] 1.75-5.13, P < 0.001), UCM (coeff. 3.88, CI 1.61-6.14, P = 0.001) and birth weight (coeff. -0.003, CI -0.005 to -0.001, P = 0.001) were the only variables independently associated with neonatal Hct. In elective CS, UCM led to higher neonatal Hct (61.5% ± 5.5) compared to eUCC without milking (55.1% ± 5.5) and dUCC (56.4% ± 5.7, P = 0.001), while in CS performed in labor there were no significant differences among the placental transfusion strategies. CONCLUSION: In term CS, neonatal Hct is significantly higher when the CS is performed in labor or with UCM. In elective CS, UCM could be a valid option to favor placental transfusion.

What's underneath? A non-destructive depth profile of painted stratigraphies by synchrotron grazing incidence X-ray diffraction.

Many works of art are complex systems consisting of a core completed by the overlapping of several painted layers. In this work, we apply an innovative method based on grazing incidence X-ray diffraction (GIXRD) with synchrotron radiation (SR) to investigate polychrome stratigraphies with a completely non-destructive approach. The SR-GIXRD measurements provided direct and unambiguous compositional and stratigraphic information of the crystalline species lying in different layers. The investigations performed on a small fragment sampled from a painted terracotta statue allowed the identification of pigments, fillers, aggregates of the matrix and newly formed decay salts in micrometric-thin paint layers. Furthermore, the great potentiality of this study is the feasibility of depth profile investigations on multi-layered painted samples from cultural heritage objects without resorting to cross sectional analyses. Currently, the method is non-destructive but it can be potentially non-invasive in situations where small moveable artworks can be placed into the measurement chamber of the SR-XRD beamlines. The overall study paves the way to a new scenario of artwork investigations, shedding light on new unexplored approaches for non-destructive studies of cultural heritage objects, their conservation history and their interaction with the environment.

Chemically and size-resolved particulate matter dry deposition on stone and surrogate surfaces inside and outside the low emission zone of Milan: application of a newly developed "Deposition Box".

The collection of atmospheric particles on not-filtering substrates via dry deposition, and the subsequent study of the particle-induced material decay, is trivial due to the high number of variables simultaneously acting on the investigated surface. This work reports seasonally resolved data of chemical composition and size distribution of particulate matter deposed on stone and surrogate surfaces obtained using a new method, especially developed at this purpose. A "Deposition Box" was designed allowing the particulate matter dry deposition to occur selectively removing, at the same time, variables that can mask the effect of airborne particles on material decay. A pitched roof avoided rainfall and wind variability; a standardised gentle air exchange rate ensured a continuous "sampling" of ambient air leaving unchanged the sampled particle size distribution and, at the same time, leaving quite calm condition inside the box, allowing the deposition to occur. Thus, the "Deposition Box" represents an affordable tool that can be used complementary to traditional exposure systems. With this system, several exposure campaigns, involving investigated stone materials (ISMs) (Carrara Marble, Botticino limestone, Noto calcarenite and Granite) and surrogate (Quartz, PTFE, and Aluminium) substrates, have been performed in two different sites placed in Milan (Italy) inside and outside the low emission zone. Deposition rates (30-90 µg cm-2 month-1) showed significant differences between sites and seasons, becoming less evident considering long-period exposures due to a positive feedback on the deposition induced by the deposited particles. Similarly, different stone substrates influenced the deposition rates too. The collected deposits have been observed with optical and scanning electron microscopes and analysed by ion chromatography. Ion deposition rates were similar in the two sites during winter, whereas it was greater outside the low emission zone during summer and considering the long-period exposure. The dimensional distribution of the collected deposits showed a significant presence of fine particles in agreement with deposition rate of the ionic fraction. The obtained results allowed to point out the role of the fine particles fraction and the importance of making seasonal studies.

Close to the diffraction limit in high resolution ATR FTIR mapping: demonstration on micrometric multi-layered art systems.

This paper is aimed at demonstrating the potentiality of high resolution Attenuated Total Reflection Fourier Transform Infrared micro-mapping (micro-ATR-FTIR) to reconstruct the images of micrometric multi-layered systems. This method can be an effective analytical alternative when the layer thickness requires high lateral resolution, and fluorescence or thermal effects prevent the deployment of conventional analytical techniques such as micro-Raman spectroscopy. This study demonstrates the high micro-ATR-FTIR setup performances in terms of lateral resolution, spectral quality and chemical image contrast using a new laboratory instrument equipped with a single element detector. The method has been first validated on mock-ups and then successfully applied on cross-sectional samples from real artworks: Leonardo da Vinci's mural painting, characterised by a few micrometers thin sequence of organic and inorganic layers, and an outdoor marble statue, with a complex sequence of decay products on its surface. This study paves the way to a new investigation modality of micrometric systems, combining high lateral resolution with excellent spectral quality, essential in the field of Cultural Heritage as well as in the wider area of materials and forensic sciences.

Investigation of Heterogeneous Painted Systems by Micro-Spatially Offset Raman Spectroscopy.

A recently developed technique of Micro-Spatially Offset Raman Spectroscopy (micro-SORS) extends the applicability of Raman spectroscopy to probing thin, highly diffusely scattering layers such as stratified paint samples, enabling their nondestructive chemical characterization. The technique has a wide applicability across areas such as cultural heritage, polymer research, forensics, and biological fields; however, currently, it suffers from a major unaddressed issue related to its ineffectiveness with highly heterogeneous samples. In this paper, we address this unmet need while demonstrating an effective strategy to probe such samples, involving a mapping on scales substantially larger than the scale of heterogeneity. This approach provides an effective means of obtaining robust and representative micro-SORS datasets from which sample composition can be effectively deduced, even in these extreme scenarios. The approach is compared with a basic point collection approach on two-layer paint systems where different layers-top, bottom, or both-are heterogeneous. The study has particular relevance to cultural heritage, where heterogeneous layers are often encountered with painted stratigraphies.

Development of neutron imaging quantitative data treatment to assess conservation products in cultural heritage.

Distribution, penetration depth and amount of new mineralogical phases formed after the interaction between an inorganic treatment and a matrix are key factors for the evaluation of the conservation treatment behaviour. Nowadays, the conventional analytical methodologies, such as vibrational spectroscopies, scanning electron microscopy and X-ray diffraction, provide only qualitative and spot information. Here, we report, for the first time, the proof of concept of a methodology based on neutron imaging able to achieve quantitative data useful to assess the formation of calcium oxalate in a porous carbonatic stone treated with ammonium oxalate. Starting from the neutron attenuation coefficient of Noto stone-treated specimens, the concentrations of newly formed calcium oxalate and the diffusion coefficient have been calculated for both sound and decayed substrates. These outcomes have been also used for a comparative study between different treatment modalities. Graphical abstract Horizontal slice at 300 mm depth and CaOx molar density profile by NEUTRA output.

Development of a Fiber-Optics Microspatially Offset Raman Spectroscopy Sensor for Probing Layered Materials.

Microspatially offset Raman spectroscopy (micro-SORS) has been proposed as a valuable approach to sample molecular information from layers that are covered by a turbid (nontransparent) layer. However, when large magnifications are involved, the approach is not straightforward, as spatial constraints exist to position the laser beam and the objective lens with the external beam delivery or, with internal beam delivery, the maximum spatial offset achievable is restricted. To overcome these limitations, we propose here a prototype of a new micro-SORS sensor, which uses bare glass fibers to transfer the laser radiation to the sample and to collect the Raman signal from a spatially offset zone to the Raman spectrometer. The concept also renders itself amenable to remote delivery and to the miniaturization of the probe head which could be beneficial for special applications, e.g., where access to sample areas is restricted. The basic applicability of this approach was demonstrated by studying several layered structure systems. Apart from proving the feasibility of the technique, also, practical aspects of the use of the prototype sensor are discussed.

Development of a full micro-scale spatially offset Raman spectroscopy prototype as a portable analytical tool.

We present, for the first time, a portable full micro-Spatially Offset Raman Spectroscopy (micro-SORS) prototype permitting the in situ analysis of thin, highly turbid stratified layers at depths not accessible to conventional Raman microscopy. The technique is suitable for the characterisation of painted layers in panels, canvases and mural paintings, painted statues and decorated objects in cultural heritage or stratified polymers, and biological, catalytic and forensics samples where invasive analysis is undesirable or impossible to perform. The new device is characterised conceptually in polymer and paint layer systems. The provision of portability with full micro-SORS delivers subsurface micro-SORS capability unlocking the non-invasive and non-destructive potential of micro-SORS at its most effective form permitting it to be applied to large and non-portable objects in situ without recourse to removing micro-fragments for laboratory analysis on benchtop Raman microscopes.

Discovering Hidden Painted Images: Subsurface Imaging Using Microscale Spatially Offset Raman Spectroscopy.

We demonstrate for the first time the mapping capability of micro-spatially offset Raman spectroscopy (micro-SORS). The technique enables to form noninvasive images of thin sublayers through highly turbid overlayers. The approach is conceptually demonstrated on recovering overpainted images in situations where conventional Raman microscopy was unable to visualize the sublayer. The specimens mimic real situations encountered in Cultural Heritage that deal, for example, with hidden paintings vandalized with graffiti or covered by superimposed painted layers or whitewash. Additionally, using a letter as a hidden image, we demonstrated the micro-SORS potential to reconstruct also a hidden writing covered, for example, with paper sheets that cannot be easily removed. Potential applications could also include other disciplines such as polymers, biological, catalytic, and forensic sciences where thin, highly turbid layers mask chemically distinct subsurface structures.

A multi-analytical approach for the characterization of wall painting materials on contemporary buildings.

Samples from Keith Haring's wall painting of the Necker Children Hospital in Paris were studied by a multi-analytical protocol. X-ray fluorescence (XRF), powder X-ray diffraction (XRDP), Electron microscope (SEM-EDS), Infrared and Raman spectroscopy (µ-FT-IR and µ-Raman) measurements were performed in order to characterize the materials and to identify the art technique used to produce this contemporary work. Materials from the mural suffered from severe detachments of materials and several fragments were found on the ground beneath. Some of these fragments, which were representative of the whole palette and stratigraphic sequence, were collected and studied. The fragments were sufficiently large to enable non-invasive measurements to be performed in order to characterize the materials. A comparison of the data of the techniques applied revealed that Haring's palette was composed of organic pigments such as Naphtol red, phthalocyanine blue and green and Hansa yellow, in accordance with those used previously by the artist in other painted murals.