Micro-chemical evaluation of ancient potsherds by μ-LIBS scanning on thin section negatives

In the study of ancient pottery, thin section analysis represents the basic approach to study mineralogical and petrografic features in order to obtain preliminary information about the production technology and origin of archaeological ceramics. However, even if thin section analysis allows investigating the textural and structural characteristics of potteries, peculiar features related to clay paste and temper composition, as well as provenance issues, can be detailed addressed only by quantitative mineralogical and chemical studies. In the realization of thin sections, a negative face is always produced, similar to the thin section itself; these remains can be used for additional analyses, such as high spatial resolution micro-chemical studies using, for example, a micro-laser induced breakdown spectroscopy (LIBS) scanner. LIBS is a spectroscopic technique that, exploiting the laser radiation, is able to bring into the plasma state micrometric portions of the sample, and to analyse its content through the study of the optical emission of the plasma itself. Unlike other techniques, LIBS can detect and quantify also light elements such as aluminium and magnesium. Images produced by the micro-LIBS instrument show the spatial distribution of the chemical elements within a portion of the sample, which may have dimensions from a few hundred microns up to several centimeters. The combination of these images with algorithms derived from image processing techniques may return interesting information and supporting data to in-depth investigate pottery components detected by optical microscopy observations. In this work, we present the results of an experimental study performed on thin-section negatives with different grain size, surface treatments and aggregates, coming from some Neolithic Italian sites, exploring the potential of the LIBS method in micro-chemical studies of ancient potsherds

Multivariate calibration in Laser-Induced Breakdown Spectroscopy quantitative analysis: The dangers of a ‘black box’ approach and how to avoid them

The introduction of multivariate calibration curve approach in Laser-Induced Breakdown Spectroscopy (LIBS) quantitative analysis has led to a general improvement of the LIBS analytical performances, since a multivariate approach allows to exploit the redundancy of elemental information that are typically present in a LIBS spectrum. Software packages implementing multivariate methods are available in the most diffused commercial and open source analytical programs; in most of the cases, the multivariate algorithms are robust against noise and operate in unsupervised mode. The reverse of the coin of the availability and ease of use of such packages is the (perceived) difficulty in assessing the reliability of the results obtained which often leads to the consideration of the multivariate algorithms as ‘black boxes’ whose inner mechanism is supposed to remain hidden to the user. In this paper, we will discuss the dangers of a ‘black box’ approach in LIBS multivariate analysis, and will discuss how to overcome them using the chemical-physical knowledge that is at the base of any LIBS quantitative analysis

Anticoagulation in the early phase of non-valvular atrial fibrillation-related acute ischemic stroke: where do we stand?

The balance between the risk of early stroke recurrence and hemorrhagic transformation represents the cornerstone of practical management of non-valvular atrial fibrillation (NVAF)-related acute ischemic stroke (AIS). Patients who receive antithrombotic therapy as secondary prevention in the early phase of NVAF-related AIS have a better prognosis compared with patients who do not receive antithrombotic treatment. Recently, the RAF study showed that the best efficacy/safety profile was associated with anticoagulation started between 4 and 14 days from stroke onset. Based on the RAF study, the 2018 American Heart Association/American Stroke Association (AHA/ASA) guidelines suggest starting anticoagulants between 4 and 14 days from stroke onset with a class of recommendation IIa. Strong evidence for the use of direct oral anticoagulants (DOACs) in the early phase of NVAF-related AIS is lacking, because this kind of patients were excluded from phase III randomized clinical trials (RCT) and ad hoc RCTs are ongoing. However, the real life evidence suggests that early starting time of DOACs in patients with NVAF-related AIS is safe and associated with low recurrence risk and all-cause mortality. In the present review the Authors provide an update on anticoagulation in the early phase of NVAF-related AIS with focus on DOACs

Microplastic contamination of lettuces grown in urban vegetable gardens in Lisbon (Portugal)

: Urban vegetable gardens are very often a feature of cities that want to offer their citizens a more sustainable lifestyle by producing their own food products. However, cities can have significant pollution levels (or pollution hotspots) due to specific sources of pollution, such as traffic. Among the various pollutants, microplastics (MPs) are emerging as a consensual concern due to the awareness of the environmental contamination, their bioaccumulation potential and human intake, and, consequently unknown human health impacts. The present study compared the content of MPs in lettuce plants cultivated in Lisbon urban gardens with those cultivated in a rural area, as well as samples bought in supermarkets. Microplastics were detected in all washed leaves, with mean levels ranging from 6.3 ± 6.2 to 29.4 ± 18.2 MPs/g. Lettuce grown in urban gardens from areas with high traffic density showed higher MPs levels. Weak positive Spearman's rank correlations were found between MPs content and concentrations of Cu and S (determined by Particle Induced X-Ray Emission, PIXE), suggesting a possible role of traffic contribution to MPs levels, as both elements are considered traffic-source tracers. These results contribute to shed light on the MP contamination of vegetables grown in such urban environments, that may represent a potential MP exposure route through the dietary intake, corresponding to a 70% increase in annual MP intake compared to lettuces bought in supermarkets

Timing and significance of exercise-induced left ventricular outflow tract pressure gradients in hypertrophic cardiomyopathy.

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Recovery of archaeological wall paintings using novel multispectral imaging approaches

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The chemical-physical knowledge before the restoration: The case of "The Plague in Lucca", a masterpiece of Lorenzo Viani (1882-1936)

Background: "The Plague in Lucca", a masterpiece of the contemporary painter Lorenzo Viani, was studied by multianalytical techniques (Multiband, IR and UV fluorescence imaging, micro-Raman spectroscopy, direct exposure-mass spectrometry, gas chromatography-mass spectrometry and energy dispersive X-ray fluorescence) in view of its restoration at the Gallery of Modern and Contemporary Art (GAMC) of Palazzo delle Muse in Viareggio (Lucca, Italy). The analysis allowed to obtain a better understanding of the artistic technique of the painter and to underline critical conservation aspects. Results: At first, non-invasive techniques, such as the Multiband Imaging, Infrared Reflectometry, UV Fluorescence and X-ray Fluorescence, have been applied in order to characterize the conservation state of the painting surface and determining the more representative zones of the painting for the taking of micro-samples to be analysed in the laboratory. The destructive chemical analysis of these micro-samples, performed using mass (DEMS and GC/MS) and infrared spectroscopy (micro-Raman), permitted to reveal the nature of the organic and inorganic materials present in the painting. Conclusions: The use of different physical and chemical diagnostic techniques allowed us to obtain precious information about the palette and the technique used by Lorenzo Viani for the realization of "La Peste a Lucca". Furthermore, this approach permit to characterize paintings, to understand the nature and origin of materials used by the artist and to develop the appropriate restoration procedure

Estimating Prognosis and Frailty in Persons Aged ≥75 Years in the Emergency Department: Further Validation of Dynamic Silver Code.

OBJECTIVES To assess concurrent validity of the Dynamic Silver Code (DSC), a tool based on administrative data that predicts prognosis in older adults accessing the emergency department (ED), in terms of association with markers of poor functional and cognitive status. DESIGN Cross-sectional. SETTING AND PARTICIPANTS Data were obtained in the AIDEA study, which enrolled a cohort of ≥75-year-old patients, accessing the ED of 2 hospitals in Florence, Italy. METHODS The DSC score and classes (I to IV, corresponding to an increasing risk of death) were obtained from administrative data. Information on health and functional status prior to ED access were collected from face-to-face, direct, or proxy interviews. The 4AT test was administered to screen for possible delirium. Bivariate comparisons of the prevalence of each functional and cognitive marker across 4 DSC classes were performed. Multinomial logistic regression was used to assess the multivariable risk of being in II, III, or IV DSC class vs I. RESULTS Among 3358 participants (mean age 83 years, men 44%), 32.9%, 30.3%, 19.5%, and 17.2% were in DSC class I, II, III, and IV. Preadmission abnormal functional and cognitive conditions, and delirium in the ED, were increasingly more common from DSC class I through IV (P < .001). In particular, the prevalence of total inability to walk increased from 2.9% (class I) to 23.4% (class IV). In multivariable analyses, this was the strongest predictor of being in progressively worse DSC classes, whereas feeling of exhaustion, reporting of serious falls, weight loss, and severe memory loss or diagnosis of dementia gave some contribution. CONCLUSIONS AND IMPLICATIONS The ability of the DSC to predict survival in older persons appears to rely on its prevailing association with markers of functional impairment. These results may support clinical use of the tool