Elemental composition of soils and sediments by using portable X-ray fluorescence (pXRF) spectroscopy: a preliminary study

Portable X-ray fluorescence spectrometry (pXRF) provides rapid and low-cost analysis in laboratory and field conditions for a wide range of environmental applications. Its successful application in soils requires a good instrument calibration and the possibility to implement custom calibrations and methods using known samples as well as reference materials. In the present study two set of samples, one from pedogenized sediments of a basin in Marradi (Italy; n=13) and the other from agricultural land in Meuse valley (Belgium; n=10), were analyzed by using a portable X-ray fluorescence (pXRF TRACER 5i made by Bruker) to detect and quantify the element species (Al, Si, Ca, Fe, Mg, K, Mn, P, S, Ba, Cd, Co, Cr, Cu, Mo, Pb, Sb, Sn, Sr and Zn). Element concentrations results were compared with analytical results from aqua regia extractions (AQ) followed by ICP-OES analysis. The aim of this work was to verify and find the best instrument setup for the specific matrix, elements and their concentration range with the purpose of using the pXRF technique directly insitu for the screening of sites potentially polluted. A standard factory calibration for soil applications was used for samples from Meuse valley, while a custom calibration for P, S, Ca and Fe quantification with the coefficient correction method was developed and used for pedogenized sediments from Marradi, as well as for Cu and Cr quantification in both sites. Comparing portable XRF and AQ results, elements could be grouped in three classes: 1) elements where the content determined by both methods is not correlated (p>0.05; Al, Si, and K); 2) elements strongly correlated (0.840.60), carbonates (Ca, r2>0.55) and oxy(hydr)oxides (Fe and Mn) have instead comparable concentrations between pXRF and AQ. Preliminary results showed that portable XRF can quickly provide data for some elucidations of important pedogenic processes involving many elements (class 2) in the studied soils. Alternative methods offer results after expensive and time-consuming analytical procedures. Moreover for environmental and human health purposes, the pXRF should be a valid tool for a rapid screening of heavy metals, such as Cu, Cr, Zn and Pb. A larger set of soil samples and further custom calibration will be tested

Linearity of Piezoresistive Nano-Gauges for MEMS Sensors

AbstractThe work discusses the mechanical properties and the response linearity of sub-micrometric crystalline Silicon beams used as piezoresistive sensing elements (nano-gauges) in MEMS sensors. The study is based on a suitably developed test structure that allows applying bidirectional stresses to a gauge with a cross-section of (250 nm)2, and to monitor the displacement both through a reference linear capacitive sensor and through the nano-gauge piezoresistive variation.Experimental measurements estimate a nominal strength of 6.6 GPa, and a linear range of 2.3 GPa and 1.1 GPa under tensile and compressive stresses respectively, the latter value being limited by buckling effects

A programmable emulator of MEMS inertial sensors

This paper presents a fully-configurable digital system that emulates MEMS inertial sensors. Its main function is to synthesize all the electro-thermo-mechanical features of the device, in order to allow the characterization of electronic systems (ASICs for MEMS or MEMS-dedicated instrumentation) coupled to the (emulated) MEMS, (i) without the need to have a physically available sensor and (ii) with the possibility to vary the sensors parameters as desired. The core of the system is constituted by an FPGA that emulates in the digital domain the behavior of the device. Thanks to its digital, hence easy-to-configure nature, it guarantees high versatility and adaptability to different emulation scenarios with a simple firmware update

stereoselective thio-Michael addition to chalcones in water catalyzed by bovine serum albumin

A biomimetic, inexpensive, and simple method for the stereoselective thio-Michael addition of thiols to chalcones has been developed using bovine serum albumin (BSA) as a catalyst. Optically active products are obtained in high yield and with enantiomeric excesses of up to 70

Stereoselective thio-Michael addition to chalcones in water catalyzed by bovine serum albumin

A biomimetic, inexpensive and simple method for the stereoselective thio-Michael addition of thiols to chalcones has been developed using bovine serum albumin (BSA) as a catalyst. Optically active products are obtained in high yield and with enantiomeric excesses of up 70

Incorporating patient-reported symptom assessments into routine care for people with chronic kidney disease

In this issue of Clinical Kidney Journal, Brown and colleagues show that symptom burden is high across all stages of chronic kidney disease (CKD). Still, management of symptoms in kidney patients leaves room for improvement, which may partly stem from symptoms being underreported. The use of patient-reported questionnaires may facilitate a more systematic approach to symptom assessment, but to date, the majority of these instruments have been used only in the context of research studies. In this editorial, we review how systematic patient-reported symptom assessments can be incorporated in CKD care. We show examples from an initiative in the UK where 14 renal units explored how to collect and use symptom burden assessments as part of their routine ways of working. We also discuss how to move from paper-based questionnaires towards digital collection of patient-reported symptom data. Lastly, we introduce wearable and smartphone sensors as novel methods for collecting information to support and enrich symptom assessments while minimizing data collection burden

Discovering the material palette of the artist : a p-XRF stratigraphic study of the Giotto panel “God the Father with Angels”

Elemental analysis, and in particular stratigraphic distribution of elements themselves, is a fundamental method to address the composition of materials, but its nature, often invasive, crashes with the necessity of avoiding artefacts' damage when dealing with Cultural Heritage objects. In fact, when work of art are involved, sampling is often forbidden, and transferring an artistic artefact to equipped laboratories is a not negligible issue. The skill to employ in situ non-destructive and non-invasive analytical method is essential. In this scenario, portable X-ray fluorescence (p-XRF) has become one of the most employed techniques due to the development of adaptable and open architecture instruments. In this paper, we show a new data analysis protocol and its application to XRF data acquired from a work by Giotto never studied before: \u2018God the Father with Angels\u2019 (ca. 1330, San Diego Museum of Art). The measurements have been performed in situ during the closing time of the exhibition \u2018Giotto, l'Italia\u2019 (Milano Palazzo Reale \u2013 2 September 2015/10 January 2016). Combining the effectiveness of scanning p-XRF with the responsive of image spectroscopic analysis, we move step by step toward the discovery of Giotto's palette for the flesh tones in God the Father with Angels; our method allows to argue the stratigraphy of the painting without complementary measurements and, at the same time, provides a sequential and smart representation of complex data

The Giotto’s workshop in the XXI century : looking inside the “God the Father with Angels” gable

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 \u201cGiotto, l'Italia\u201d 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 \u201cGod the Father\u201d and for the faces of angels

Reasons for underreporting of uraemic pruritus in people with chronic kidney disease: A qualitative study.

CONTEXT Uraemic pruritus, or itch, is common in people with chronic kidney disease (CKD) and has a negative impact on their lives and well-being. However, for reasons currently unknown, itch often remains unreported and therefore untreated. OBJECTIVES To explore reasons for underreporting of itch in order to provide pointers for improving itch reporting and management in people with CKD. METHODS We interviewed adult patients with CKD who self-reported experiencing itching in the last three years (n=25), nephrologists (n=10) and nurses (n=12) from three kidney services in the United Kingdom. Topic guides were informed by previous studies and a theoretical model of self-regulation. We conducted a thematic analysis of verbatim transcripts using Framework Analysis. RESULTS We identified three main themes reflecting factors that may influence whether itch is reported: knowledge on causes and treatment of itch (lack of awareness of the relationship between itch and CKD; lack of knowledge of treatment options); attitudes towards importance of itch as a health issue (patients' attitudes; clinicians' attitudes); and prompts for itch assessment during consultations (routine practice; itch as a marker; itch severity). CONCLUSIONS Underreporting of itch is related to patients being unaware of its causes, accepting it as something to live with, prioritising other health issues, and the length and timing of consultations. Healthcare professionals' assessment and management of itch vary widely and are not necessarily evidence-based. Better patient information, development of clinical practice guidelines, and incorporation of routine symptom assessments into care may improve itch reporting and management in people with CKD