Priming Layer Research Articles

Forecasting Epidemic Spread with Recurrent Graph Gate Fusion Transformers.

Predicting the unprecedented, nonlinear nature of COVID-19 presents a significant public health challenge. Recent advances in deep learning, such as Graph Neural Networks, Recurrent Neural Networks (RNNs), and Transformers, have enhanced predictions by modeling regional interactions, managing autoregressive time series, and identifying long-term dependencies. However, prior works often feature shallow integration of these models, leading to simplistic graph embeddings and inadequate analysis across different graph types. Additionally, excessive reliance on historical COVID-19 data limits the potential of utilizing time-lagged data, such as intervention policy information. To address these challenges, we introduce ReGraFT, a novel Sequence-to-Sequence model designed for robust long-term forecasting of COVID-19. ReGraFT integrates Multigraph-Gated Recurrent Units (MGRUs) with adaptive graphs, leveraging data from individual states, including infection rates, policy changes, and interstate travel. First, ReGraFT employs adaptive MGRU cells within an RNN framework to capture inter-regional dependencies, dynamically modeling complex transmission dynamics. Second, the model features a Self-Normalizing Priming layer using SELUs to enhance stability and accuracy across short, medium, and long-term forecasts. Lastly, ReGraFT systematically compares and integrates various graph types derived from fully connected layers, pooling, and attention-based mechanisms to provide a nuanced representation of inter-regional relationships. By incorporating lagged COVID-19 policy data, ReGraFT refines forecasts, demonstrating RMSE reductions of 2.39-35.92% compared to state-of-the-art models. This work provides accurate long-term predictions, aiding in better public health decisions. Our code is available at https://github.com/mfriendly/ReGraFT.

Adaptive Adhesions of Barnacle-Inspired Adhesive Peptides.

The strategy of robust adhesion employed by barnacles renders them fascinating biomimetic candidates for developing novel wet adhesives. Particularly, barnacle cement protein 19k (cp19k) has been speculated to be the key adhesive protein establishing the priming layer in the initial barnacle cement construction. In this work, we systematically studied the sequence design rationale of cp19k by designing adhesive peptides inspired by the low-complexity STGA-rich and the charged segments of cp19k. Combining structure analysis and the adhesion performance test, we found that cp19k-inspired adhesive peptides possess excellent disparate adhesion strategies for both hydrophilic mica and hydrophobic self-assembled monolayer surfaces. Specifically, the low-complexity STGA-rich segment offers great structure flexibility for surface adhesion, while the hydrophobic and charged residues can contribute to the adhesion of the peptides on hydrophobic and charged surfaces. The adaptive adhesion strategy identified in this work broadens our understanding of barnacle adhesion mechanisms and offers valuable insights for designing advanced wet adhesives with exceptional performance on various types of surfaces.

Biodeterioration effects of three Aspergillus species on stucco supported on a wooden panel modeled from Sultan al-Ashraf Qaytbay Mausoleum, Egypt

This study focuses on the magnificent decoration of a painted and gilded wooden panel with signs of fungal biodeterioration caused by Aspergillus species in the Mausoleum of Sultan al-Ashraf Qaytbay, Cairo, Egypt. Numerous spectroscopic analyses and investigation techniques, including Scanning Electron Microscope Equipped with Energy Dispersive X-ray analysis (SEM–EDX), Fourier Transform Infrared analysis (FTIR), and X-Ray Diffraction (XRD) have been used to study the materials that comprise this painted and gilded wooden panel composition. Aspergillus niger, A. flavus, and A. terreus were recognized as isolated fungi, and their accession numbers are OQ820164, OQ820163, and OQ820160, respectively. The findings showed that the wooden support is of pinewood (Pinus halepensis), the white priming layer on top of the wooden support was identified as gypsum, the blue paint layer has been proposed to be Azurite, Au (gold) was the primary composition of the gilding layer, while Pb (lead) was detected in some spots, suggesting the use an alloy of gold with lead, and finally, animal glue was the bonding medium. Based on these findings, mimic samples with identical substrates and structural components have been designed, and the biodeterioration signs by the growing of the three Aspergillus species—A. niger, A. flavus and A. terreus were evaluated via SEM and color change. However, A. niger was discovered with density growth on surfaces of pinewood, gypsum, and Azurite and with less growth on the gilding layer after 6-month incubation. This contrasts with A. terreus and A. flavus, which had greater density growth on Azurite and stucco than on pinewood and less growth on the gilding layer. The used analytical methods with detailed analyses revealed the novelty and significant future aspects of the conservation of the painted and gilded wooden panel. Particularly given that this location is used for prayer and is crowded with people five times a day, which increases the accumulation of fungi and negatively affects both the historic Mosque and the worshippers' health.

Technical and economic assessment for choosing of bridge structures waterproofing under cast hot asphalt concrete

The existing technical level analysis of the polymeric materials requirements determination for waterproofing of the bridge structure carriageway slab is carried out. Nowadays new durable sprayed materials based on isocyanate: polyurea, polyurethanes, polycarbonates find mass application in transport construction. The waterproofing layer is applied on the priming layer by hot spraying method using special equipment, with the formation of a strong, elastic, seamless, waterproof coating, which when applied reproduces the shape of the geometry of the insulated surface. To ensure the service life, recommendations for improving the bridge structures sprayed polymer waterproofing technology at low temperatures are developed. The technological solution providing the directed thermophysical regulation of bridge structures roadway slab sprayed polymer waterproofing based on the isocyanates at low temperatures on the basis of prevention and elimination defects (caverns) point is presented. The technical and economic calculation confirming the sprayed waterproofing technology application efficiency in comparison with traditionally used roll materials have been carried out. Due to the new technology application, the number of current repairs is reduced from 24 to eight for a range of 49 years. By calculation means using the programme developed by the author, the discounted payback period for the sprayed polymer waterproofing technology was established at the beginning of the 17th year.

Identification of materials in oil paintings through studies of correlations and ratios between the element line intensities during LIBS stratigraphy

Small fragments of the oil paintings “Emmaus Dinner” by Bellini (XVII century) and “Annunciation” by Brughi (XVIII century) were taken to laboratory because of insufficient information collected in-situ. At first, the samples were analyzed by SEM-EDX and FTIR Spectroscopy in order to identify the elemental and molecular composition of the surface layers, mostly covered by Ca-based patina (calcium oxalate and carbonates). Afterwards, the depth profiling by LIBS made possible to distinguish surface contaminations and retouches from the original pictorial materials. Stratigraphic variations of the chemical composition were established by a proper normalization of the element line intensities, necessary due to large changes of overall plasma intensity during ablation of heterogeneous samples. So obtained layer separations were confirmed by Principal Component Analysis (PCA). Studies of the correlations and ratios between intensities of the analytical element lines were effective to identify pigments and priming layers and, in some cases, to indicate also a possible material provenance. In the Bellini's painting we identified Natural Umber, Azurite, Green Earth, Goethite, Lead-Tin Yellow and Lead White, the latter detected in all examined fragments. The surface contamination by debris and retouches by modern pigments containing Ba, Cr and Zn were also detected. The presence of K and Na in the priming layer suggests the use of glass, commonly employed in the XVII century. In the Brughi's painting we identified a thin layer of Ultramarine Blue placed over Green Earth layer while the priming layer was mainly constituted by gypsum. On this painting, we also detected surface restoration by Ba based modern pigments.

Characterization of the mural blue paintings in ornamental motif of Ali Qapu palace in Isfahan, Iran, using spectroscopic and microscopic methods (a case study)

This study aimed to investigate the painting technique and identify the blue pigments used in the ornamental motif of mural paintings of Ali Qapu palace as the seat of rule of Shah Abbas I Safavid and part of Naghsh-e Jahan square world heritage site in Isfahan. For this investigation, five samples collected from the murals located at different sections of the palace were studied by polarized light microscopy (PLM), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and energy-dispersive X-ray spectroscopy (EDS). Also, the Fourier self-deconvolution was applied to the FTIR spectra of chloroform extract of the paint layer to identify the type of binder used in the painting. The results showed that the blue pigment used in all five samples is natural ultramarine (lapis lazuli). In four of the five samples, huntite has been used as the filler in the priming layer. However, the results suggest that huntite has also been combined with ultramarine to create lighter tonalities. The findings indicate the use of three different priming methods in creating the ornamental motif murals: creating a priming layer with iron-rich soil, creating a priming layer with huntite as the filler, and placing an organic layer underneath the huntite priming layer. This shows the variety of priming techniques used in creating the ornamental motif murals of Ali Qapu. Furthermore, FTIR results indicate the possible use of the tempera and oil technique in the murals.

Technical Study of the Paint Layers from Buddhist Sculptures Unearthed from the Longxing Temple Site in Qingzhou, China

In 1996, more than four hundred Buddhist statues were excavated from the Hoard of Longxing Temple site in Qingzhou, Shandong Province, China. They are of great significance in the study of Buddhism history during the Northern and Southern Dynasties of China, and have attracted widespread attention since they were unearthed. In this paper, the paint layers from 14 of the Buddhist statues unearthed from the Longxing Temple site were analyzed using portable 3D microscopy, Raman spectroscopy and X-ray fluorescence spectroscopy was used to determine the materials used in their production. Several microscopic samples were analyzed in the laboratory using scanning electron microscopy/energy dispersive spectrometer, X-ray diffraction and micro-Raman spectroscopy. The combined results from the field and laboratory analyses materials used in painting layers of these statues were identified, and the technique for the production of the sculptures was studied. After the stone sculpture of Buddha was finished, a priming layer of lead white was applied over the stone body as a ground, over which pigments were applied. These include mineral pigments (cinnabar, malachite, lapis lazuli and cerussite), Chinese ink (carbon black) and gold leaf. Cinnabar was used for the outer garments, the halos and ornaments of Buddha and Bodhisattva statues; malachite, was found primarily on the Monk’s clothing; the blue pigment, lapis lazuli, was mainly used for the Buddha’s bun, halo and outer garment edges; carbon black ink was employed for drafting and sketching clothing and decorative patterns.

Micro-Raman spectroscopy and complementary techniques applied for the analysis of rock art paintings at the archaeological locality La Angostura, lower valley of Chubut River (Patagonia, Argentina)

In this paper, we characterized for the first time the painting materials in rock art panels of the Patagonian archaeological locality La Angostura using a methodological approach that combined micro-Raman spectroscopy, attenuated total reflection Fourier Transform infrared spectroscopy, and X-ray fluorescence spectroscopy. In this way, we obtained detailed information on the red, green, and black pigments as well as on accessory minerals present in the paints. Hematite was the chromophore in the red paintings while celadonite and glauconite were identified in the green motifs. A manganese oxide, presumably pyrolusite, was characterized as the black pigment. The pigment compositions were also compared to those of natural sediments collected along the valley of the Chubut River, but the components of the red and green sediment samples differed from those present in the rock art paints. In the red motifs of two of the rock art panels, a relevant finding was the presence of gypsum and anhydrite as a priming layer of the corrugated rock support onto which the red paints were applied. This revealed a different painting technique in comparison to that at the other analyzed panels of La Angostura where paints were applied as thin layers on a smooth surface of the rock support. As far as we know, this is the first report on the identification of gypsum and anhydrite as components of a preparation layer in Patagonian rock art. This result contributes to the open discussion on the origin and function of calcium sulfate in rock art.

Effects of polydopamine coatings on nucleation modes of surface mineralization from simulated body fluid

Polydopamine (PDA) has been recently used as a versatile priming layer for further functionalization of a biomaterial surface, particularly in biomimetic mineralization of biomaterials. Yet most of the existing literature is on inorganic substrates and the underlying effects of the PDA layer coatings on the nucleation and mineralization process and the mineral-substrate interface have not been clearly identified. Here we aimed to investigate the effects of the PDA layer on the nucleation and growth and interfacial morphology of calcium phosphate mineral layer (CaP) from 10× simulated body fluid (10× SBF) on polymeric substrates. It is found that the nucleation of CaP on PDA-coated surface favors a mixed “islanding” and planar growth mode (Stranski–Krastanov) while the “islanding” mode (Volmer–Weber) was observed on the surface without PDA. This different early nucleation stage of mineralization was found to correlate with a more “bonded” interface between the mineral layer and the PDA-coated substrates, a slight increase in the interfacial strength and a different delamination mode. This study therefore provided new insights on how polydopamine priming layer influenced the mineralization process and the interface between the mineral layer and the substrate.

Scenes from the life of Picasso’s Still Life (1922): history, materials, and conservation

Pablo Picasso manipulated his paints to achieve a range of visual effects in his painting Still Life (Art Institute of Chicago, 1953.28). The addition of excess medium and the superposition of multiple paint layers with different drying rates contributed to localized areas of wrinkling, tenting, and lifting paint. Discolored surface coatings and overpaint from an early restoration treatment posed challenges to the understanding and conservation treatment of the work. Research and analysis were undertaken to study Picasso’s process and to aid treatment decisions. X-ray and infrared imaging revealed that Picasso had originally painted a neo-classical still life on the canvas. He applied a lead-white-based priming layer over the first composition before painting the linear abstract Still Life dated February 4, 1922. The results of pyrolysis–gas chromatography-mass spectrometry analysis of paint samples and restoration coatings from past treatments helped to clarify our understanding of the painting and supplement previously published analytical results.

Expanding the Scope of Surface Grafted Polymers Using Electroinitiated Polymerization.

The ability to rapidly modify the surface of materials is a powerful means of tailoring interfaces and interphases for a variety of applications. In this work, we demonstrate the extensive scope of an electrochemically mediated surface modification technique, able to install a range of surface grafted polymers of varying polarity and functionality. The irreversible reduction of aryldiazonium salts initiates polymer growth and provides a "priming layer" for the polymers to attach to, covalently anchoring them to the surface. We show the broad applicability of this technique through polymerization of 19 acrylate monomers, as well as a noncarbonyl bearing monomer species, styrene. Surface bound films were characterized using FT-IR, ellipsometry, and water contact angle.

Immobilization of Antimicrobial Silver and Antioxidant Flavonoid as a Coating for Wound Dressing Materials.

PurposeThe aim of this study is to develop a new coating for wound dressings that is comprised of antimicrobial silver (Ag) and antioxidant flavonoid quercetin (Q).MethodsDip-coating was used to apply the coating on cotton gauge as a model dressing. Ag was immobilised using polydopamine as a priming and catalytic layer followed by coating of quercetin that was incorporated in a functionalized polydimethylsiloxane. The coating was investigated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and release assay. The antimicrobial activity of quercetin and Ag was tested against Staphylococcus aureus (S. aureus). A surgical wound model on mice was used to evaluate the effects of the coated dressing on wound healing rates and tissue histology.ResultsAg and quercetin showed enhanced antimicrobial activity against S. aureus when used in combination. Ag and quercetin were successfully immobilized onto the fibre of the dressing using the dip-coating process. The coating released Ag and quercetin over 8 days and showed strong antioxidant activity. In the wound healing model, complete wound closure was achieved in 12 days in the group receiving coated dressing and was associated with an enhancement in tissue remodelling and neo-angiogenesis and the reduction in tissue inflammation.ConclusionThese new antimicrobial-antioxidant coatings may be promising in the development of advanced wound care therapies.

Spectroscopic and chromatographic investigation of the wall painted surfaces of an 18th century Indian temple, New Delhi

Understanding and building knowledge about color pigments, their history and development have always been a matter of great interest through scientific exploration in the complex system of identification. The characterization of historical works of art is complicated due to the association of several other elements that influence the recorded observations. This entails investigations with multi-analytical techniques to identify the archaeological pigments and confirm their characteristics. The spectroscopic techniques especially Raman spectroscopy and Infrared spectroscopy are very useful for the identification of such materials. In the present communication, the pigments of an historical 18th century wall painting were investigated with micro-Raman spectroscopy, FTIR-ATR & FTIR-KBr, and scanning electron microscopy coupled with energy dispersive x-ray micro-analysis (SEM-EDX). The temple is an exquisite Hindu architecture with valuable artworks still surviving in New Delhi. The results demonstrated the use of red ochre contaminated with carbon for red, yellow ochre for yellow, green ochre for green color and gypsum for the white color in decorations. Lapis lazuli was identified as a pigment for blue probably sourced from Afghanistan through trade on the silk route. The stratigraphy of layers showed the use of lime as a priming layer. FTIR spectroscopy revealed the minor transformation of proteinaceous binding material into calcium oxalate in the paint layer. GC–MS results indicated the possible use of beeswax as a binder for pigments which was further support by FTIR analysis. The analytical data also reveals the trade and resources available in that period.

Raman and Fourier transform infrared microspectroscopies reveal medieval Hispano–Muslim wood painting techniques and provide new insights into red lead production technology

AbstractThis paper describes the study of two Nasrid polychrome wooden ceilings from the Alhambra monumental ensemble using vibrational spectroscopic techniques. The study is focused on the identification of the constituent materials and execution techniques used employing non‐invasive and non‐destructive scientific investigation methods. Information about both inorganic (pigments) and organic (binders and coatings) materials has been obtained without the need for time‐consuming procedures. A complex stratigraphy involving the use of a protective priming layer of red lead covered with animal glue and white lead was revealed. The identification of Raman signatures of different lead oxide compounds, including lead‐tin oxide (Pb2SnO4), in the priming layer, allowed us to hypothesize the synthesis of red lead (Pb3O4) from litharge (α‐PbO), a common by‐product of the cupellation process used since antiquity for silver production. Furthermore, the pigments employed in hidden drawings found in the reverse of the wood pieces of one of the ceilings were also studied and compared with those found in the visible external face.

Identification of pigments in the Annunciation sculptural group (Cordoba, Spain) by micro-Raman spectroscopy.

A highly flexible method based on micro-Raman spectroscopy was used to examine pigment traces on an Annunciation sculpture group dating from the late Middle Ages. The group comprises a statue of the Archangel Gabriel and another of the Virgin Mary. Both are currently housed in the Archaeological Museum of Cordoba, southern Spain. Information about the pigment palette used by the artists of the time to decorate religious limestone sculptures was for the first time obtained. The pigments found included vermilion (HgS), hematite (α-Fe2O3), azurite [Cu3(CO3)2(OH)2], cerussite (PbCO3) and anatase (TiO2). None was directly applied to the sculptures; rather, the limestone was coated with a primer containing calcium carbonate (possibly chalk or half-chalk). The polychromy on both sculptures, which was originally applied in the XV century and seriously damaged in the XVIII, had been treated with an ochre-coloured priming layer of gypsum to make it more uniform and optically similar to the underlying stone.

Characterization of Wallpaintings from the Caliphal Baths of Cordoba (Spain) by X-Ray Diffraction and Raman Microspectroscopy

Wallpainting fragments from the Caliphal Baths of Cordoba, Spain, were studied in this work for the first time. X-ray diffraction (XRD) and Raman microspectroscopy allowed the chemical nature of the pigments used by the Arabic artists of the time to be identified. All pigments were applied over a gypsum priming layer. The white, red, and yellow colors used were obtained from gypsum, hematite, and goethite, respectively. Some pigments were prepared by mixing these materials. The analytical techniques used also allowed the mortar material to be identified. The results of this study may be useful to develop effective conservation strategies for archaeological remains.

A Painted Viking-Age Sculpture from York

This paper records and discusses a recent discovery of a Viking-age stone carving from York, the subsequent cleaning and conservation of which has revealed large areas of original lime plaster priming layer and pigment coating, including the first recorded use in Northumbrian sculpture of lead white.

Significant Performance Enhancement of Polymer Resins by Bioinspired Dynamic Bonding.

Marine mussels use catechol-rich interfacial mussel foot proteins (mfps) as primers that attach to mineral surfaces via hydrogen, metal coordination, electrostatic, ionic, or hydrophobic bonds, creating a secondary surface that promotes bonding to the bulk mfps. Inspired by this biological adhesive primer, it is shown that a ≈1 nm thick catecholic single-molecule priming layer increases the adhesion strength of crosslinked polymethacrylate resin on mineral surfaces by up to an order of magnitude when compared with conventional primers such as noncatecholic silane- and phosphate-based grafts. Molecular dynamics simulations confirm that catechol groups anchor to a variety of mineral surfaces and shed light on the binding mode of each molecule. Here, a ≈50% toughness enhancement is achieved in a stiff load-bearing polymer network, demonstrating the utility of mussel-inspired bonding for processing a wide range of polymeric interfaces, including structural, load-bearing materials.

Surface Modification: Simple Multipurpose Surface Functionalization by Phase Transited Protein Adhesion (Adv. Mater. Interfaces 2/2015)

By exploiting the lysozyme from egg white that is distinct from classical polydopamines, P. Yang and co-workers report in article 1400401 a universal method for multipurpose functionalization on arbitrary material surfaces. Small molecules, macromolecules and colloids are immobilized onto versatile substrates of metals, oxides, and synthetic polymers by manipulating the phase-transited protein as a priming layer.

A study on the painting techniques and materials of the murals in the Five Northern Provinces’ Assembly Hall, Ziyang, China

A limited amount of analytical data is available on the techniques and materials used in the murals of the Qing dynasty (1636–1911) in China. The Five Northern Provinces’ Assembly Hall (1861–1874) is located in Wafangdian on the confluence of two rivers. It has the largest murals in Shaanxi Province. This paper presents the first comprehensive investigation of the painting techniques and materials of the murals in the Five Northern Provinces’ Assembly Hall. The analytical methods include polarized light microscopy (PLM), microscopic examination on cross-sections, x-ray fluorescence (XRF), x-ray diffraction (XRD), micro-Raman spectroscopy (μ-RS), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with an energy-dispersive spectrometer (SEM-EDX), which have been used to examine the paint layer stratigraphy, plaster layers, the priming layer and inorganic pigments composition. The results show that the carrier was firstly prepared with two levels of coarse layers, which are made of clay, sand and rice straw applied onto the brick wall, and a fine coat layer made of lime, clay, sand and cotton follows. Then a kaolin-pigmented priming layer was painted on the fine coat, which was finally painted with red lead, red ochre, cinnabar, atacamite, malachite, botallackite, orpiment, yellow ochre, Prussian blue, smalt, azurite, lead white and flame carbons on top. The research suggests that the painting materials of the murals of the Five Northern Provinces’ Assembly Hall are original and the techniques were well implemented and followed the traditional and standard way in ancient China. But a few details present strong local characteristics, such as using rice straw, cotton and kaolin as original materials which were more convenient to obtain. This study also indicates that only one red dyestuff was found, and the other colourants are all inorganic. Except Prussian blue, smalt and botallackite used in ancient mural in China were less reported, and the rest of the pigments represent traditional Chinese painting materials. In addition, the usage of the imported pigments Prussian blue and smalt proves that the geographic position of the Five Northern Provinces’ Assembly Hall was of crucial importance for trade.