A fast non-invasive method for preliminary authentication of mediaeval glass enamels using UV–visible–NIR diffuse reflectance spectrophotometry

2020 ◽  
Vol 45 ◽  
pp. 33-40
Author(s):  
Maurizio Aceto ◽  
Gaia Fenoglio ◽  
Maria Labate ◽  
Marcello Picollo ◽  
Mauro Bacci ◽  
...  
Keyword(s):  
Diffuse Reflectance ◽  
Reflectance Spectrophotometry ◽  
Non Invasive ◽  
Invasive Method ◽  
Uv Visible

scholarly journals Non-Invasive Study on the Sinope Gospels

Heritage ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 1269-1278
Author(s):  
Maurizio Aceto ◽  
Elisa Calà ◽  
Angelo Agostino ◽  
Gaia Fenoglio ◽  
Maria Labate ◽  
...  
Keyword(s):  
Diffuse Reflectance ◽  
Pure Gold ◽  
Late Antique ◽  
Reflectance Spectrophotometry ◽  
Purple Colour ◽  
X Ray ◽  
Non Invasive ◽  
Ultramarine Blue ◽  
Uv Visible

The 6th century Codex Sinopensis or Sinope Gospels (Paris, Bibliothèque nationale de France) is one of the most precious purple codices that survive from the Late Antique period. Together with the Vienna Genesis (Wien, Österreichische Nationalbibliothek) and the Rossano Gospels (Rossano Calabro, Museo Diocesano), it has an unusually rich decorative apparatus with scenes representing biblical episodes. It can be, therefore, considered one of the most important preserved artistic productions of the early medieval era. The manuscript has been subjected to a non-invasive diagnostic campaign to evaluate the quality of the colourants used in its decoration, to understand how the parchment was coloured, and to carry out a comparison with the Vienna Genesis and the Rossano Gospels. The techniques used were UV-visible diffuse reflectance spectrophotometry with optical fibres (FORS), X-ray fluorescence spectrometry (XRF), spectrofluorimetry, and optical microscopy. Analyses highlighted the presence of ultramarine blue, which, besides the use of pure gold for the ink and paint, certifies the high value of the manuscript. In addition, this must be seen as one of the earliest examples of its use in paintings. The purple colour of the parchment was identified as orchil, a dye extracted from lichens, similar to the results of analytical investigations carried out on other purple codices, and not the expected Tyrian purple dye.

scholarly journals Detecting the NIR Fingerprint of Colors: The Characteristic Response of Modern Blue Pigments

Heritage ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 2255-2261 ◽  
Author(s):  
Yivlialin ◽  
Galli ◽  
Raimondo ◽  
Martini ◽  
Sassella
Keyword(s):  
Diffuse Reflectance ◽  
Near Infrared ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
Composite Sample ◽  
Model Composite ◽  
Non Invasive ◽  
Uv Visible ◽  
Invasive Techniques

Reflectance spectroscopy in the ultraviolet (UV), visible (Vis), and near infrared (NIR) range is widely applied to art studies for the characterization of paints and pigments, with the advantages of non-invasive techniques. Isolating and detecting the fingerprint of pigments, especially in the NIR range, is quite challenging, since the presence of vibrational transitions of the most common organic functional groups prevents to relate the optical spectrum of a composite sample, as an artwork is, to each one of its elements (i.e., support, binder, and specific pigment). In this work, a method is presented to obtain the UV-Vis-NIR optical response of the single components of a model composite sample reproducing an artwork, i.e., the support, the binder, and the pigment or dye, by using diffuse reflectance spectroscopy. This allowed us to obtain the NIR spectral fingerprint of blue pigments and to identify specific features possibly applicable for detecting cobalt and phthalocyanine blue colors in artwork analysis.

scholarly journals Synthesis and Optimization of Visible Light Active BiVO4Photocatalysts for the Degradation of RhB

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Rong Ran ◽  
Joanne Gamage McEvoy ◽  
Zisheng Zhang
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Reflectance Spectrophotometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Range ◽  
Excellent Photocatalytic Activity ◽  
Visible Light Active ◽  
Uv Visible

Monoclinic BiVO4powders were synthesized via a novel route using potassium metavanadate (KVO3) prepared by calcination of K2CO3and V2O5as a starting material and followed by hydrothermal treatment and were investigated for the degradation of Rhodamine B (RhB) under visible light irradiation. The synthesized BiVO4particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-Visible (UV-Vis) light diffuse reflectance spectrophotometry. The synthesis produced pure monoclinic BiVO4particles with multimorphological features containing flower-like, flake-ball, flake, cuboid-like, and plate-like shapes and exhibited strong absorption in the visible light range. The BiVO4prepared via KVO3possessed excellent photocatalytic activity for the degradation of RhB under visible light. The performance of this catalyst was found to be superior to other BiVO4photocatalysts prepared via ammonium metavanadate (NH4VO3) using coprecipitation, combustion, and calcination methods reported in literature, respectively.

Malfunctional Reorganization in the Developing Limbo-Prefrontal System in Animals: Implications for Human Psychoses?

2001 ◽  
Vol 12 (1) ◽  
pp. 8-14
Author(s):  
Gertraud Teuchert-Noodt ◽  
Ralf R. Dawirs
Keyword(s):  
Prefrontal Cortex ◽  
Mental Disorders ◽  
Dentate Gyrus ◽  
Cognitive Functions ◽  
Experimental Approach ◽  
Regulatory Mechanisms ◽  
Hippocampal Dentate Gyrus ◽  
Non Invasive ◽  
Invasive Method ◽  
Activity Dependent

Abstract: Neuroplasticity research in connection with mental disorders has recently bridged the gap between basic neurobiology and applied neuropsychology. A non-invasive method in the gerbil (Meriones unguiculus) - the restricted versus enriched breading and the systemically applied single methamphetamine dose - offers an experimental approach to investigate psychoses. Acts of intervening affirm an activity dependent malfunctional reorganization in the prefrontal cortex and in the hippocampal dentate gyrus and reveal the dopamine position as being critical for the disruption of interactions between the areas concerned. From the extent of plasticity effects the probability and risk of psycho-cognitive development may be derived. Advance may be expected from insights into regulatory mechanisms of neurogenesis in the hippocampal dentate gyrus which is obviously to meet the necessary requirements to promote psycho-cognitive functions/malfunctions via the limbo-prefrontal circuit.

scholarly journals CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation

2021 ◽  
Author(s):  
Patrick Veit-Haibach ◽  
Martin W. Huellner ◽  
Martin Banyai ◽  
Sebastian Mafeld ◽  
Johannes Heverhagen ◽  
...  
Keyword(s):  
Peripheral Arterial Disease ◽  
Ct Perfusion ◽  
Arterial Disease ◽  
Lower Leg ◽  
Therapy Control ◽  
Non Invasive ◽  
Before And After ◽  
Invasive Method ◽  
The Mean ◽  
Peripheral Arterial

Abstract Objectives The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation. Methods Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests. Results The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min−1. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively). Conclusions CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease. Key Points • CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients. • This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

scholarly journals Asymmetric TCD Findings in Malignant MCA Infarction, Resolution after Decompressive Hemicraniectomy: A Case Report

2020 ◽  
Vol 12 (Suppl. 1) ◽  
pp. 127-136
Author(s):  
Hazel Gaile  Barrozo ◽  
Maria Anna De Guzman ◽  
Jose  Navarro ◽  
Narayanaswamy Venketasubramanian
Keyword(s):  
Pressure Effects ◽  
Mean Flow ◽  
Brain Swelling ◽  
Decompressive Hemicraniectomy ◽  
Non Invasive ◽  
Invasive Method ◽  
Malignant Mca Infarction ◽  
Subsequent Rise ◽  
Very High ◽  
Hemispheric Infarct

Transcranial Doppler (TCD) is a non-invasive method for assessing cerebral hemodynamics in the acute phase of stroke. We report a case of a 33-year-old man who presented with a massive left hemispheric infarct developing into “malignant” MCA infarction. TCD was utilized to monitor intracranial hemodynamics while the clinical and neuroimaging findings were used to help us in the decision to proceed with decompressive craniectomy (DC). Pre-operatively, there was reduced mean flow velocities (MFV) of the middle cerebral artery (MCA) with increasing pulsatility index (PI) ipsilateral to the infarct. The subsequent but smaller rise in the PI in the contralateral MCA was suggestive of very high intracranial pressure (ICP) from massive brain swelling. Serial TCD examinations post-operatively showed normalization of the PI, and subsequent rise in the left MCA MFV. Clinical improvement was also noted as the TCD findings improved. The asymmetry in TCD findings can be attributed to occlusion of the MCA with subsequent spontaneous recanalisation, occlusion of the MCA with subsequent recanalisation due to the DC, or initial occlusion and subsequent pressure effects on the arterioles of the MCA due to the “malignant” edema of that hemisphere that was relieved by DC. This case illustrates the value of TCD as a useful modality in monitoring intracranial hemodynamics in acute stroke.

CEUS detection of biliary ischaemia during the first 4 weeks after liver transplantation predicts non-anastomotic biliary stricture

2021 ◽  
pp. 1-12
Author(s):  
Bo-wen Zheng ◽  
Shu-hong Yi ◽  
Tao Wu ◽  
Mei Liao ◽  
Ying-cai Zhang ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Predictive Value ◽  
Biliary Stricture ◽  
Characteristic Curve ◽  
Validation Group ◽  
Gamma Glutamyl Transpeptidase ◽  
Full Cohort ◽  
Non Invasive ◽  
Invasive Method ◽  
Nas Score

BACKGROUND: Biliary ischaemia is an important factor in the pathogenesis of non-anastomotic biliary stricture (NAS) after liver transplantation (LT). Contrast-enhanced ultrasound (CEUS) can be used to detect biliary ischaemia, but no study has examined the utility of CEUS in predicting NAS. OBJECTIVE: To evaluate whether repeated CEUS as a non-invasive method of biliary ischaemia can identify NAS. METHODS: Consecutive LT patients who underwent CEUS examinations at 1–4 weeks after LT from September 2012 to December 2015 at our institution were included. The CEUS images and clinical data were analysed. RESULTS: Among 116 eligible LT patients, 39 (33.6%) were diagnosed with NAS within 1 year after LT. The patients with NAS had a significantly higher CEUS score at weeks 2–4 (all P <  0.05) and a higher slope of CEUS score progression (0.480 vs –0.044, P <  0.001). The accuracy of CEUS in identifying NAS improved over time after LT, reaching its maximum at week 4, with a sensitivity of 66.7%, a specificity of 87.9%, a positive predictive value (PPV) of 75.9%, a negative predictive value (NPV) of 82.3%, and an accuracy of 80.2%in the full cohort when a CEUS score≥3 was used as the cut-off. Multivariate analysis identified gamma-glutamyl transpeptidase (GGT), alanine transaminase (ALT) and the CEUS score at week 4 as independent predictors of NAS. In the task of identifying NAS, an NAS score combining the above 3 variables at week 4 showed areas under the receiver operating characteristic curve of 0.88 (95%CI, 0.78–0.99) in the estimation group (n = 60) and 0.82 (95%CI, 0.69–0.96) in the validation group (n = 56). An NAS score cut-off of 0.396 identified 87.2%of NAS cases in the estimation group, with a PPV of 93.3%; and 75.0%of NAS cases in the validation group, with a PPV of 58.8%. CONCLUSIONS: CEUS examination during the first 4 weeks is useful in assessing the risk of NAS within 1 year after LT. In particular, an NAS score combining the CEUS score, GGT level, and ALT level at week 4 can be used to accurately predict the risk of NAS in LT patients.

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