Sensorineural hearing loss (SNHL) affects the inner ear compartment and can be caused by different factors. Usually, the lack, death, or malfunction of sensory cells deputed to transduction of mechanic-into-electric signals leads to SNHL. To date, the therapeutic option for patients impaired by severe or profound SNHL is the cochlear implant (CI), a high-tech electronic device replacing the entire cochlear function. Piezoelectric materials have catalyzed attention to stimulate the auditory neurons by simply mimicking the function of the cochlear sensory epithelium. In this study, the authors investigated lithium niobate (LiNbO 3 ) as a potential candidate material for next generation CIs. LiNbO 3 nanoparticles resulted otocompatible with inner ear cells in vitro, had a pronounced immunomodulatory activity, enhanced human beta-defensin in epithelial cells, and showed direct antibacterial activity against P. aeruginosa. Moreover, LiNbO 3 nanoparticles were incorporated into poly(vinylidene fluoride-trifluoro ethylene) fibers via electrospinning, which enhanced the piezoelectric response. Finally, the resulting fibrous composite structures support human neural-like cell growth in vitro, thus showing promising features to be used in new inner ear devices.

Collagen is a key structural protein in the human body, which undergoes mineralization during the formation of hard tissues. Earlier studies have described the mechanical behavior of bone at different scales highlighting material features across hierarchical structures. Here we present a study that aims to understand the mechanical properties of mineralized collagen fibrils upon tensile/compressive transient loads, investigating how the kinetic energy propagates and it is dissipated at the molecular scale, thus filling a gap of knowledge in this area. These specific features are the mechanisms that Nature has developed to passively dissipate stress and prevent structural failures. In addition to the mechanical properties of the mineralized fibrils, we observe distinct nanomechanical behaviors for the two regions (i.e., overlap and gap) of the Dperiod to highlight the effect of the mineralization. We notice decreasing trends for both wave speeds and Young's moduli over input velocity with a marked strengthening effect in the gap region due to the accumulation of the hydroxyapatite. In contrast, the dissipative behavior is not affected by either loading conditions or the mineral percentage, showing a stronger dampening effect upon faster inputs compatible to the bone behavior at the macroscale. Our results improve the understanding of mineralized collagen composites unveiling the energy dissipative behavior of such materials. This impacts, besides the physiology, the design and characterization of new bioinspired composites for replacement devices (e.g., prostheses for sound transmission or conduction) and for optimized structures able to bear transient loads, e.g., impact, fatigue, in structural applications.

In this paper, we report a few examples showing how energy dispersive XRF analysis (EDXRF) coupled with visible reflectance spectroscopy (vis‐RS) can be successfully applied for the investigation of wood or canvas paintings by performing stratigraphic analyses with non‐invasive techniques. The specific aim is to reconstruct layers and their thicknesses. The method has been tested in the laboratory on paint layers similar to traditional Renaissance ones. In situ analyses of a famous wood painting by Andrea Mantegna—‘Madonna col bambino e un coro di cherubini’, Pinacoteca di Brera, Milan—were also carried out. While illustrating the results concerning the identification of pigments and the discrimination of layer stratigraphy, advantages and limitation of this method are pointed out. Copyright © 2007 John Wiley & Sons, Ltd.

This paper describes the physico-chemical analyses performed on an Egyptian wood coffin on the occasion of its restoration in the hall of the National Archaeological Museum of Parma (Italy), with the aim of investigating the pigments and organic materials originally used. Pigment determination was performed both in situ by a portable energy-dispersive X-ray fluorescence (EDXRF) spectrometer and in the laboratory using a micro-Fourier-transforminfrared (micro-FTIR) and a Fourier-transform (FT) Raman spectrometer. The identification of organic materials was performed through gas chromatography -mass spectrometry (GC-MS) and micro-FTIR analysis. Amongst the pigments, special attention was paid to the green, which appeared to be severely degraded and was examined using powder X-ray diffraction (XRD) and scanning electron microscopy -energy-dispersive X-ray (SEM-EDX) in addition to the above-cited techniques. Other materials used in the polychromatic decorations are Egyptian blue, cinnabar and possibly orpiment, while calcium carbonate was used for the ground layer. The organic materials were identified as beeswax, mastic and gum arabic, sometimes as mixtures.

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