The mucosal pellicle (MP) is a biological film protecting the oral mucosa. It is composed of bounded salivary proteins and transmembrane mucin MUC1 expressed by oral epithelial cells. Previous research indicates that MUC1 expression enhances the binding of the main salivary protein forming the MP, MUC5B. This study investigated the influence of MUC1 structure on MP formation. A TR146 cell line, which does not express MUC1 natively, was stably transfected with genes coding for three MUC1 isoforms differing in the structure of the two main extracellular domains: the VNTR domain, exhibiting a variable number of tandem repeats, and the SEA domain, maintaining the two bound subunits of MUC1. Semi-quantification of MUC1 using dot blot chemiluminescence showed comparable expression levels in all transfected cell lines. Semi-quantification of MUC5B by immunostaining after incubation with saliva revealed that MUC1 expression significantly increased MUC5B adsorption. Neither the VNTR domain nor the SEA domain was influenced MUC5B anchoring, suggesting the key role of the MUC1 N-terminal domain. AFM-IR nanospectroscopy revealed discernible shifts indicative of changes in the chemical properties at the cell surface due to the expression of the MUC1 isoform. Furthermore, the observed chemical shifts suggest the involvement of hydrophobic effects in the interaction between MUC1 and salivary proteins.

Conventional techniques that measure the concentration of light elements in metallic materials lack high-resolution performance due to their intrinsic limitation of sensitivity. In that context, scanning microwave microscopy has the potential to significantly enhance the quantification of element distribution due to its ability to perform a tomographic investigation of the sample. Scanning microwave microscopy associates the local electromagnetic measurement and the nanoscale resolution of an atomic force microscope. This technique allows the simultaneous characterization of oxygen concentration as well as local mechanical properties by microwave phase shift and amplitude signal, respectively. The technique was calibrated by comparison with nuclear reaction analysis and nanoindentation measurement. We demonstrated the reliability of the scanning microwave technique by studying thin oxygen-enriched layers on a Ti-6Al-4V alloy. This innovative approach opens novel possibilities for the indirect quantification of light chemical element diffusion in metallic materials. This technique is applicable to the control and optimization of industrial processes.

Surface texturing is one of the most technologically appropriate laser surface treatment applications. Over the past few decades, texturing has emerged as an attractive surface engineering option and has been used by researchers to generate micro/nanopatterns on operating surfaces. This technique can create simple or complex patterns on component surfaces depending on their aesthetic or functional goals and without altering the overall properties. In addition, this non-contact process can be applied to hard-to-reach areas. Recently, laser surface texturing has been applied to improve the adhesion of contact surfaces. Several authors have demonstrated the impact and benefits of textured surfaces to achieve optimal adhesion of coatings and increase in-service behavior. Nevertheless, based on the laser-matter interaction phenomena, chemical and mechanical transformations of the surfaces can be noticed but are difficult to characterize. Indeed, the affected layers are of the order of a few hundred nanometers. Then, analyses must be performed with variable levels of resolution in order to analyze the structural, chemical and mechanical characteristics of the matter. To develop new applications of unconventional assemblies and improved adhesion of new materials, a control of these local modifications is required.

Significant efforts have been done in last two decades to develop nanoscale spectroscopy techniques owning to their great potential for single-molecule structural detection and in addition, to resolve open questions in heterogeneous biological systems, such as protein–DNA complexes. Applying IR-AFM technique has become a powerful leverage for obtaining simultaneous absorption spectra with a nanoscale spatial resolution for studied proteins, however the AFM-IR investigation of DNA molecules on surface, as a benchmark for a nucleoprotein complexes nanocharacterization, has remained elusive. Herein, we demonstrate methodological approach for acquisition of AFM-IR mapping modalities with corresponding absorption spectra based on two different DNA deposition protocols on spermidine and Ni 2+ pretreated mica surface. The nanoscale IR absorbance of distinctly formed DNA morphologies on mica are demonstrated through series of AFM-IR absorption maps with corresponding IR spectrum. Our results thus demonstrate the sensitivity of AFM-IR nanospectroscopy for a nucleic acid research with an open potential to be employed in further investigation of nucleoprotein complexes.

Laser surface texturing has emerged as an environmental technological option and fast developing technique to provide different surface conditions. In order to improve its efficiency, it is necessary to overcome the usual trial and error approach by carefully mastering operating parameters. The present work analyzes the effects of a pulsed nanosecond laser beam on the processing of titanium surfaces. The textured surfaces were characterized using various experimental techniques, including scanning microwave microscopy (SMM). The results show the impact of laser fluence, number of laser pulses and laser dimple pitch on textured surfaces mainly from a morphological (microscopies) and mechanical (XRD and SMM) perspective. The topography was analyzed according to the laser texturing parameters. A model of the cumulative effect of the number of laser pulses has been demonstrated. In addition, laser texturing modifies the surface residual stresses. Laser texturing effects on the surface mechanical state were analyzed by varying the laser texturing parameters and also by comparing isolated textured dimples and textured regions as a whole. Many changes were found such as surface topography and residual stresses, surface changes that need to be characterized and known to provide a better understanding of the performance and operating behavior of the materials.

Flavor is one of the main drivers of food consumption and acceptability. It is associated with pleasure feels during eating. Flavor is a multimodal perception corresponding to the functional integration of information from the chemical senses: olfaction, gustation, and nasal and oral somatosensory inputs. As a result, astringency, as a sensation mediated by the trigeminal nerves, influences food flavor. Despite the importance of astringency in food consumer acceptance, the exact chemosensory mechanism of its detection and the nature of the receptors activated remain unknown. Herein, after reviewing the current hypotheses on the molecular origin of astringency, we proposed a ground-breaking hypothesis on the molecular mechanisms underpinning this sensation as a perspective for future research.

Whichever the application field, every material forming process generates residual stresses on the surface. While they are likely to enhance the aimed properties of the final mechanical part, these stresses may also drastically reduce them and result in early failures. Therefore, understanding the residual stress state remains a major challenge when coating complex parts, especially as most characterization methods at the microscopic scale involve specific sample preparation procedures which may affect the residual stresses field. This work investigates the residual stress state that exists in chromium oxide coatings deposited via Atmospheric Plasma Spray (APS), using two pioneering techniques featuring high spatial resolution: Scanning Microwave Microscopy and Raman Micro-Spectroscopy. The first technique combines the measurement of microwave electromagnetic capacities of a Vector Network Analyzer with the subnanometric resolution of an Atomic Force Microscope: it thus enables performing depth investigations at very accurately defined positions of the probe on the surface. The second technique relies on the principle of photons inelastic scattering and involves a laser beam aiming at the material sample: it allows a fine characterization of the microstructure as well as defects and stresses detection via molecular vibratory signatures. The investigation scale is limited here to a few cubic micrometers. Due to the highly localized scales of our investigations, which also depend on the device, the objective of our procedure required that the comparison should be made not on individual points but on definite mapped areas, every spot being analyzed and post-treated one after another, with optimum measuring parameters. Results have been correlated with XRD measurements to cross-check the average amount of stress observed over a wider area.

Le parchemin est une peau d’animal minutieusement preparee pour servir de support a l’ecriture. Comment elabore-t-on un parchemin ? Qui sont les eleveurs de betail, les parcheminiers au Moyen-Âge ? Vous le decouvrirez grâce aux chartes, registres et partitions musicales exposes.

Supported lipid bilayers represent a very attractive way to mimic biological membranes, especially to investigate molecular mechanisms associated with the lateral segregation of membrane components. Observation of these model membranes with high-speed atomic force microscopy (HS-AFM) allows the capture of both topography and dynamics of membrane components, with a spatial resolution in the nanometer range and image capture time of less than 1 s. In this context, we have developed new protocols adapted for HS-AFM to form supported lipid bilayers on small mica disks using the vesicle fusion or Langmuir-Blodgett methods. In this chapter we describe in detail the protocols to fabricate supported artificial bilayers as well as the main guidelines for HS-AFM imaging of such samples.

The mucosal pellicle, also called salivary pellicle, is a thin biological layer made of salivary and epithelial constituents, lining oral mucosae. It contributes to their protection against microbiological, chemical, or mechanical insults. Pellicle formation depends on the cells' surface properties, and in turn the pellicle deeply modifies such properties. It has been reported that the expression of the transmembrane mucin MUC1 in oral epithelial cells improves the formation of the mucosal pellicle. Here, we describe an approach combining classical and functionalized tip atomic force microscopy and scanning microwave microscopy to characterize how MUC1 induces changes in buccal cells' morphology, hydrophobicity, and electric properties to elucidate the physicochemical mechanisms involved in the enhancement of the anchoring of salivary proteins. We show that MUC1 expression did not modify drastically the morphology of the epithelial cells' surface. MUC1 expression, however, resulted in the presence of more hydrophobic and more charged areas at the cell surface. The presence of salivary proteins decreased the highest attractive and repulsive forces recorded between the cell surface and a functionalized hydrophobic atomic force microscopy (AFM) tip, suggesting that the most hydrophobic and charged areas participate in the binding of salivary proteins. The cells' dielectric properties were altered by both MUC1 expression and the presence of a mucosal pellicle. We finally show that in the absence of MUC1, the pellicle appeared as a distinct layer poorly interacting with the cells' surface. This integrative AFM/scanning microwave microscopy approach may usefully describe the surface properties of various cell types, with relevance to the bioadhesion or biomimetics fields.

A color image is the result of a very complex physical process. This process involves both light reflectance due to the surface of the object and the sensor. The sensor is the human eye or the image acquisition system. To avoid metamerism phenomena and to give better rendering to the color images resulting from the synthesis, it is sometimes necessary to work in the spectral field. Now, we meet two classes of methods that enable the closest spectral image to be produced from color images. The first method uses circular and exponential functions. The second method uses the Penrose inverse or the Wiener inverse. In this article, we first of all describe the two methods used in a variety of fields from image synthesis to colorimetry not to forget satellite imagery. We then propose a new method linked with the neural network so as to improve the first two approximation methods. This new method can also be used for calibrating most of color digitization systems and sub wavelengths color array filters.

Conductive indium-tin oxide (ITO) and non-conductive glass substrates were successfully modified with embedded gold nanoparticles (AuNPs) formed by controlled thermal annealing at 550 °C for 8 h in a preselected oven. The authors characterized the formation of AuNPs using two microscopic techniques: scanning electron microscopy (SEM) and atomic force microscopy (AFM). The analytical performances of the nanostructured-glasses were compared regarding biosensing of Hsp70, an ATP-driven molecular chaperone. In this work, the human heat-shock protein (Hsp70), was chosen as a model biomarker of body stress disorders for microwave spectroscopic investigations. It was found that microwave screening at 4 GHz allowed for the first time the detection of 12 ng/µL/cm2 of Hsp70.

The interaction of tannins with salivary proteins is involved in astringency. This paper focussed on saliva lining oral mucosae, the mucosal pellicle. Using a cell-based model, the impact of two dietary tannins (EgC and EgCG) on the mucosal pellicle structure and properties was investigated by microscopic techniques. The role of basic Proline-Rich-Proteins (bPRPs) in protecting the mucosal pellicle was also evaluated. At low (0.05 mM) tannin concentration, below the sensory detection threshold, the distribution of salivary mucins MUC5B on cells remained unaffected. At 0.5 and 1 mM, MUC5B-tannin aggregates were observed and their size increased with tannin concentration and with galloylation. In addition, 3 mM EgCG resulted in higher friction forces measured by AFM. In presence of bPRPs, the size distribution of aggregates was greatly modified and tended to resemble that of the "no tannin" condition, highlighting that bPRPs have a protective effect against the structural alteration induced by dietary tannins.

A technique based on scanning microwave microscopy (SMM) has recently been developed to analyze solid solutions of light elements. This technique consists in local measurements of effects produced by electrical conductivity variations produced by light elements solutions in metals. The penetration of the microwaves into the metals depends on their frequency and the material parameters. Information regarding the local conductivity of the material at different depths can be recorded using various frequencies. In this paper, SMM measurements of the oxygen-enriched zone are presented for several materials: TA6V, pure Ti, and pure Zr. Comparisons with concentration measurements made by nuclear reaction analysis allow one to affirm that for all the materials investigated here the phase shift measured by SMM is proportional to the oxygen concentration dissolved into the metal. Calibration functions are proposed for each material and frequency used. After calibration, the SMM can be used to measure local enrichments.

Metallic nanoparticles are considered as active supports in the development of specific chemical or biological biosensors. Well-organized nanoparticles can be prepared either through expensive (e.g., electron beam lithography) or inexpensive (e.g., thermal synthesis) approaches where different shapes of nanoparticles are easily obtained over large solid surfaces. Herein, the authors propose a low-cost thermal synthesis of active plasmonic nanostructures on thin gold layers modified glass supports after 1 h holding on a hot plate (~350 °C). The resulted annealed nanoparticles proved a good reproducibility of localized surface plasmon resonance (LSPR) and surface enhanced Raman spectroscopy (SERS) optical responses and where used for the detection of low concentrations of two model (bio)chemical molecules, namely the human cytochrome b5 (Cyt-b5) and trans-1,2-bis(4-pyridyl)ethylene (BPE).