Search results for "RAMAN"

Bioactive glass ions induce efficient osteogenic differentiation of human adipose stem cells encapsulated in gellan gum and collagen type I hydrogels

2019

Abstract Background Due to unmet need for bone augmentation, our aim was to promote osteogenic differentiation of human adipose stem cells (hASCs) encapsulated in gellan gum (GG) or collagen type I (COL) hydrogels with bioactive glass (experimental glass 2-06 of composition [wt-%]: Na2O 12.1, K2O 14.0, CaO 19.8, P2O5 2.5, B2O3 1.6, SiO2 50.0) extract based osteogenic medium (BaG OM) for bone construct development. GG hydrogels were crosslinked with spermidine (GG-SPD) or BaG extract (GG-BaG). Methods Mechanical properties of cell-free GG-SPD, GG-BaG, and COL hydrogels were tested in osteogenic medium (OM) or BaG OM at 0, 14, and 21 d. Hydrogel embedded hASCs were cultured in OM or BaG OM fo…

Thermodynamics of interaction between risedronic acid and metal cations: investigations in solution and in the solid state

2019

Risedronic acid (see Figure 1) belongs to the class of biphosphonates (BP), widely used in the medical field to treat bone disorders. Bisphosphonates (BPs, e.g., alendronate, risedronate, and ibandronate) help to maintain bone mass, to inhibit osteoclast-mediated bone resorption, and to reduce the risk of both vertebral and non-vertebral fractures. The clinical efficacy of BPs is mainly based on two key properties: their capacity to strongly bind hydroxyapatite crystals of bone, and their inhibitory effects on osteoclast precursors and mature osteoclasts. Interaction of risedronate with metal cations is poorly investigated. Qualitatively, it is indicated that adsorption of risedronate is in…

MICROSCOPIC TECHNIQUES AND A MULTI-ANALYTICAL APPROACH TO CHARACTERIZE THE MATERIALS OF TWO RUSSIAN ICONS

2018

Two 19th century Russian icons, from the Museo Diocesano of Palermo, were analysed by UV photography, X-ray fluorescence, energy-dispersive X-ray fluorescence (ED-XRF), optical microscopy, micro-Raman spectroscopy and Scanning Electron Microscopy, combined with energy dispersive x-ray analysis, (SEM/EDS). The multi-analytical study of the icons “Protezione della Madre di Dio” (Pokrov’s Icon, Protection of Holy Mother of God) and ‘’Madre di Dio Gioia di Tutti gli Afflitti’’, (Holy Mother of God, Joy of all the afflicted), have been performed to reveal materials and technological features of the original painting of the 19th century as well as the materials used during past restoration works.…

Thermally induced doping in controlled atmosphere on Graphene

2017

Since its experimental breakthrough discovery in 2004, Graphene (Gr) paved the way for the study of the "flatland" of two dimensional (2D) materials. These systems are an emerging topic of interest in solid state physics and amterial sciences, but nont only, and today count a family of monoatomic layer of C atoms in hexgonal honey comb crystalline structure.

O2 trapping in silica nano-structures with high specific surfaces

2014

We report an experimental investigation regarding the entrapping of O2 molecules inside various silica nano– structured systems having specific surfaces from 50 to 1000 m2/g. By recording Raman spectra and Near Infrared O2 emission we studied the O2 content per mass unit. Our data show that the internal voids of these nanostructured systems can trap O2 molecules diffusing from the surrounding air or from a pure O2 atmosphere, whereas the concentration of O2 that can be trapped in the silica near–surface layer is at least one order of magnitude lower. This low ability is consistently observed in non–porous and porous silica nanoparticles and in mesoporous silica systems. Furthermore, we obse…

Influence of application method on the use of ammonium phosphate as preservative

2018

This work deals with the application of the Ammonium Hydrogen Phosphate as preservative and consolidant during the restoration and consolidation intervention on a twin columns group in the east side of the Santa Maria La Nova Cloister in Monreale, UNESCO Heritage from 2016. The Superintendency for Fine Arts in Palermo prescribes the use of ammonium phosphate as the only acceptable material for the consolidation of the Cloister, so this work deals with the influence of application method and solution concentration on the results achievable with this material. Particularly as the treatment have to be done on vertical surfaces the use of a supporting material is mandatory so the focus is on th…

La Madonna della Lavina di Cerami: preentazione estetica, osservazione dei materiali di restauro

2011

Intervento di restauro conservativo di un dipinto murale staccato, raffigurante la "Presentazione della Vergine al tempio", attribuito alla scuola de…

2014

Il restauro della lunetta dipinta: "Cristo e l'Eterno ai lati del mondo"

2015

Oggetto del nostro contributo è lo studio ed il restauro della lunetta dipinta raffigurante “Cristo e l’Eterno ai lati del mondo” realizzata da Simone de Wobreck nel 1562. L’intervento è stato realizzato come prova abilitante alla professione nell’ambito delle attività laboratoriali del Cdl in Conservazione e Restauro dei Beni Culturali, dell’Università di Palermo, con la direzione della Galleria Regionale di Palazzo Abatellis [1]. Di particolare interesse è stato lo studio dell’opera in relazione alla tecnica esecutiva utilizzata dall’autore, allo stato di conservazione ed ai precedenti interventi che l’opera ha subito negli anni. La tavola dipinta raffigura Cristo e l’Eterno ai lati del m…

Mortars and Plasters under the Mosaics and the Wall Paintings of the Roman Villa at Piazza Armerina, Sicily

2010

The Roman Villa at Piazza Armerina in Sicily, built in many successive steps over the 2nd and 3rd centuries A.D., is renowned all over the world for both the wealth and the refinement of its mosaic floors. In February 2007 the Regional Government of Sicily started a restoration project of the whole archaeological site. The systematic survey and study of all decorative elements highlighted the value of wall paintings, which until then were almost unknown except for casual approaches to specific problems of conservation, carried on without any relation to the far and away famous mosaics. This paper shows the results of a physical chemical investigation of the mortars used for both floors and …