111 research outputs found
Efficiency of applying ammonium oxalate for protection of monumental limestone by poultice, immersion and brushing methods
The âHistorical Materials BAGâ: A new facilitated access to synchrotron X-ray diffraction analyses for cultural heritage materials at the European Synchrotron Radiation Facility
(This article belongs to the Special Issue Advances in Analytical Strategies to Study Cultural Heritage Samples)The European Synchrotron Radiation Facility (ESRF) has recently commissioned the new Extremely Brilliant Source (EBS). The gain in brightness as well as the continuous development of beamline instruments boosts the beamline performances, in particular in terms of accelerated data acquisition. This has motivated the development of new access modes as an alternative to standard proposals for access to beamtime, in particular via the âblock allocation groupâ (BAG) mode. Here, we present the recently implemented âhistorical materials BAGâ: a community proposal giving to 10 European institutes the opportunity for guaranteed beamtime at two X-ray powder diffraction (XRPD) beamlinesâID13, for 2D high lateral resolution XRPD mapping, and ID22 for high angular resolution XRPD bulk analysesâwith a particular focus on applications to cultural heritage. The capabilities offered by these instruments, the specific hardware and software developments to facilitate and speed-up data acquisition and data processing are detailed, and the first results from this new access are illustrated with recent applications to pigments, paintings, ceramics and wood.The Historical materials BAG has been implemented with support from the European Unionâs Horizon 2020 research and innovation programme under grant agreement No 870313, Streamline, which also supports APC. L. H. is funded via the PANOSC project (European Unionâs Horizon 2020 Research and Innovation programme under Grant Agreement No. 823852). I. F. is funded by a grant from the Marie SkĆodowska-Curie COFUND Programme âInnovaXNâ (contract number 847439 with the European Commission). The ESRF beamtime was granted through the peer-review BAG proposal HG-172 at ID13 and ID22 and in-house beamtime at ID21. The project on wood vessels received financial support from MINECO (Spain), Ref. PID2019-105823RB-I00. The project on cadmium red pigments was financially supported from the Horizon 2020 project IPERION-HS (H2020-INFRAIA-2019-1, GA No. 871034) and the Italian project AMIS (Dipartimenti di Eccellenza 2018â2022, funded by MIUR and Perugia University). V.G. has received funding from the European Unionâs Horizon 2020 research and innovation programme under the Marie SkĆodowska-Curie grant agreement No 945298-ParisRegionFP. E.A.C. and K.J. would like to acknowledge the project Smart*Light funded by the Interreg V Flanders-Netherlands program with financial support from the European Regional Development Fund (ERDF) for funding in assessing the damage caused by X-rays to model paints. K.J. acknowledges FWO (Brussels) for financial support through grants G054719N and I001919N. F.V. and K.J. acknowledge BELSPO (Brussels) for funding of the FEDtWIN mandate Macro-Imaging. C.C. (Christelle Chauffeton) is grateful to the Fondation Bettencourt-Schueller and the CitĂ© de la CĂ©ramique SĂšvres-Limoges, France for founding her work in the frame of her PhD thesis. A part of this study has been funded by the Grant-in-Aid for Scientific Research [18700680], JSPS Grant-in-Aid for Young Scientists (B) from the Ministry of Education, Culture, Sports, Science and Technology of Japan.Peer ReviewedArticle signat per 28 autors/es: Marine Cotte, Victor Gonzalez, Frederik Vanmeert, Letizia Monico, Catherine Dejoie, Manfred Burghammer, LoĂŻc Huder, Wout de Nolf, Stuart Fisher, Ida Fazlic, Christelle Chauffeton, Gilles Wallez, NĂșria JimĂ©nez, Francesc Albert-Tortosa, Nati SalvadĂł, Elena Possenti, Chiara Colombo, Marta Ghirardello, Daniela Comelli, Ermanno Avranovich Clerici, Riccardo Vivani, Aldo Romani, Claudio Costantino, Koen Janssens, Yoko Taniguchi, Joanne McCarthy, Harald Reichert and Jean Susini.Postprint (published version
Protection of Stone Monuments Using a Brushing Treatment with Ammonium Oxalate
Stone monuments and buildings are susceptible to weathering. Carbonate-based stones are especially vulnerable in acidic environments, whereas magmatic acidic stones are more susceptible to chemical weathering in basic environments. To slow down surface corrosion of limestone and marble artworks/buildings, protective coatings which inhibit calcite dissolution have been proposed. In this work, samples from two stone types with different porosity were treated with ammonium oxalate (AmOx) to create a protective layer of calcium oxalate (CaOx) using the previously developed brushing method. Two different synchrotron microscopy experiments were performed to determine its protective capability. X-ray powder diffraction (SR-ÎŒ-XRPD) in transmission geometry allowed visualization of the distributions of calcium carbonate and oxalates along the sample depths. In a second step, X-ray fluorescence (SR-ÎŒ-XRF) was used to check the efficiency/integrity of the protective surface coating layer. This was done by measuring the sulfur distribution on the stone surface after exposing the protected stones to sulfuric acid. XRPD showed the formation of a protective oxalate layer with a thickness of 5â15 ”m on the less porous stone, while a 20â30 ”m thick layer formed on the more porous stone. The XRF study showed that the optimal treatment time depends on the stone porosity. Increasing the treatment time from 1 to 3 h resulted in a decreased efficiency of the protective layer for the low porosity stone. We assume that this is due to the formation of vertical channels (cracks) in the protective layer
Plasmonic gold-embedded TiO2 thin films as photocatalytic self-cleaning coatings
Transparent photocatalytic TiO2 thin films hold great potential in the development of self-cleaning glass surfaces, but suffer from a poor visible light response that hinders the application under actual sunlight. To alleviate this problem, the photocatalytic film can be modified with plasmonic nanoparticles that interact very effectively with visible light. Since the plasmonic effect is strongly concentrated in the near surroundings of the nanoparticle surface, an approach is presented to embed the plasmonic nanostructures in the TiO2 matrix itself, rather than deposit them loosely on the surface. This way the interaction interface is maximised and the plasmonic effect can be fully exploited. In this study, pre-fabricated gold nanoparticles are made compatible with the organic medium of a TiO2 solgel coating suspension, resulting in a one-pot coating suspension. After spin coating, homogeneous, smooth, highly transparent and photoactive gold-embedded anatase thin films are obtained
Probing the chemistry of CdS paints in The Scream by in situ noninvasive spectroscopies and synchrotron radiation x-ray techniques
The degradation of cadmium sulfide (CdS)-based oil paints is a phenomenon potentially threatening the iconic painting The Scream (ca. 1910) by Edvard Munch (Munch Museum, Oslo) that is still poorly understood. Here, we provide evidence for the presence of cadmium sulfate and sulfites as alteration products of the original CdS-based paint and explore the external circumstances and internal factors causing this transformation. Macroscale in situ noninvasive spectroscopy studies of the painting in combination with synchrotron-radiation x-ray microspectroscopy investigations of a microsample and artificially aged mock-ups show that moisture and mobile chlorine compounds are key factors for promoting the oxidation of CdS, while light (photodegradation) plays a less important role. Furthermore, under exposure to humidity, parallel/secondary reactions involving dissolution, migration through the paint, and recrystallization of water-soluble phases of the paint are associated with the formation of cadmium sulfates
Common variable immunodeficiency in two kindreds with heterogeneous phenotypes caused by novel heterozygous NFKB1 mutations
NFKB1 haploinsufficiengcy was first described in 2015 in three families with common variable immunodeficiency (CVID), presenting heterogeneously with symptoms of increased infectious susceptibility, skin lesions, malignant lymphoproliferation and autoimmunity. The described mutations all led to a rapid degradation of the mutant protein, resulting in a p50 haploinsufficient state. Since then, more than 50 other mutations have been reported, located throughout different domains of NFKB1 with the majority situated in the N-terminal Rel homology domain (RHD). The clinical spectrum has also expanded with possible disease manifestations in almost any organ system. In silico prediction tools are often used to estimate the pathogenicity of NFKB1 variants but to prove causality between disease and genetic findings, further downstream functional validation is required. In this report, we studied 2 families with CVID and two novel variants in NFKB1 (c.1638-2A>G and c.787G>C). Both mutations affected mRNA and/or protein expression of NFKB1 and resulted in excessive NLRP3 inflammasome activation in patient macrophages and upregulated interferon stimulated gene expression. Protein-protein interaction analysis demonstrated a loss of interaction with NFKB1 interaction partners for the p.V263L mutation. In conclusion, we proved pathogenicity of two novel variants in NFKB1 in two families with CVID characterized by variable and incomplete penetrance.Peer reviewe
Common variable immunodeficiency in two kindreds with heterogeneous phenotypes caused by novel heterozygous NFKB1 mutations
NFKB1 haploinsufficiengcy was first described in 2015 in three families with common variable immunodeficiency (CVID), presenting heterogeneously with symptoms of increased infectious susceptibility, skin lesions, malignant lymphoproliferation and autoimmunity. The described mutations all led to a rapid degradation of the mutant protein, resulting in a p50 haploinsufficient state. Since then, more than 50 other mutations have been reported, located throughout different domains of NFKB1 with the majority situated in the N-terminal Rel homology domain (RHD). The clinical spectrum has also expanded with possible disease manifestations in almost any organ system. In silico prediction tools are often used to estimate the pathogenicity of NFKB1 variants but to prove causality between disease and genetic findings, further downstream functional validation is required. In this report, we studied 2 families with CVID and two novel variants in NFKB1 (c.1638-2A>G and c.787G>C). Both mutations affected mRNA and/or protein expression of NFKB1 and resulted in excessive NLRP3 inflammasome activation in patient macrophages and upregulated interferon stimulated gene expression. Protein-protein interaction analysis demonstrated a loss of interaction with NFKB1 interaction partners for the p.V263L mutation. In conclusion, we proved pathogenicity of two novel variants in NFKB1 in two families with CVID characterized by variable and incomplete penetrance.Peer reviewe
Highly specific X-ray powder diffraction imaging at the macroscopic and microscopic scale
Plumbonacrite Identified by X-ray Powder Diffraction Tomography as a Missing Link during Degradation of Red Lead in a Van Gogh Painting
Red lead, a semiconductor pigment used by artists since antiquity, is known to undergo several discoloration phenomena. These transformations are either described as darkening of the pigment caused by the formation of either plattnerite (ÎČâPbO) or galena (PbS) or as whitening by which red lead is converted into anglesite (PbSO) or (hydro)cerussite (2âPbCOâ
Pb(OH); PbCO). Xâray powder diffraction tomography, a powerful analytical method that allows visualization of the internal distribution of different crystalline compounds in complex samples, was used to investigate a microscopic paint sample from a Van Gogh painting. A very rare lead mineral, plumbonacrite (3âPbCOâ
Pb(OH)â
PbO), was revealed to be present. This is the first reported occurrence of this compound in a painting dating from before the mid 20th century. It constitutes the missing link between on the one hand the photoinduced reduction of red lead and on the other hand (hydro)cerussite, and thus sheds new light on the whitening of red lead
XRDUA : crystalline phase distribution maps by two-dimensional scanning and tomographic (micro) X-ray powder diffraction
Imaging of crystalline phase distributions in heterogeneous materials, eitherplane projected or in virtual cross sections of the object under investigation, canbe achieved by scanning X-ray powder diffraction employing X-ray micro beamsand X-ray-sensitive area detectors. Software exists to convert the two-dimensional powder diffraction patterns that are recorded by these detectorsto one-dimensional diffractograms, which may be analysed by the broad varietyof powder diffraction software developed by the crystallography community.However, employing these tools for the construction of crystalline phasedistribution maps proves to be very difficult, especially when employing micro-focused X-ray beams, as most diffraction software tools have mainly beendeveloped having structure solution in mind and are not suitable for phaseimaging purposes.XRDUAhas been developed to facilitate the execution of thecomplete sequence of data reduction and interpretation steps required toconvert large sequences of powder diffraction patterns into a limited set ofcrystalline phase maps in an integrated fashion
- âŠ