Urban Geology for the Enhancement of the Hypogean Geosites: the Perugia Underground (Central Italy)

AbstractUrban geology analyses natural risks and promotes geoheritage in urban areas. In the cities, characterized by a high cultural value, the hypogean artificial cavities, often present in the downtown, offer a unique opportunity to show the geological substratum. Moreover, these places could be a point of interest in urban trekking with the abiotic component of the landscape as a topic (geotourism). To investigate these areas, rigorous bibliographic research and a geomorphological assessment are the first steps, but, besides, non-invasive methods are new techniques increasingly in demand. In this paper, we present a multidisciplinary study on the Etruscan Well (third century B.C.), one of the most important Etruscan artefacts in Perugia (Umbria region, Central Italy). The characteristics of the sedimentary deposits outcropping along the perimeter walls have been collected. Moreover, to show the underground geoheritage, we provide a 3D model of the well and the surrounding area integrating a georeferenced laser scanner survey with ground-penetrating radar prospecting. We aim to obtain a tridimensional mapping of accessible internal rooms to depict the geological characteristics of the Etruscan Well, also revealing a surrounding network of buried galleries. The results are not only a meaningful advancement in the archaeological, geological and historical knowledge of the downtown of Perugia but are a hint for the geoheritage promotion and dissemination, providing images and 3D reconstruction of underground areas

Tunable Porous Organic Crystals: Structural Scope and Adsorption Properties of Nanoporous Steroidal Ureas

Previous work has shown that certain steroidal bis-(N-phenyl)ureas, derived from cholic acid, form crystals in the P61 space group with unusually wide unidimensional pores. A key feature of the nanoporous steroidal urea (NPSU) structure is that groups at either end of the steroid are directed into the channels and may in principle be altered without disturbing the crystal packing. Herein we report an expanded study of this system, which increases the structural variety of NPSUs and also examines their inclusion properties. Nineteen new NPSU crystal structures are described, to add to the six which were previously reported. The materials show wide variations in channel size, shape, and chemical nature. Minimum pore diameters vary from ∼0 up to 13.1 Å, while some of the interior surfaces are markedly corrugated. Several variants possess functional groups positioned in the channels with potential to interact with guest molecules. Inclusion studies were performed using a relatively accessible tris-(N-phenyl)urea. Solvent removal was possible without crystal degradation, and gas adsorption could be demonstrated. Organic molecules ranging from simple aromatics (e.g., aniline and chlorobenzene) to the much larger squalene (Mw = 411) could be adsorbed from the liquid state, while several dyes were taken up from solutions in ether. Some dyes gave dichroic complexes, implying alignment of the chromophores in the NPSU channels. Notably, these complexes were formed by direct adsorption rather than cocrystallization, emphasizing the unusually robust nature of these organic molecular hosts

Application of atomic force microscopy to characterize liposomes as drug and gene carriers

At present, liposomes play a significant role as drug delivery vehicles being considered very promising for gene therapeutics. The in vivo application of these systems widely dependent on their physico-chemical and technological characteristics such as the structure, shape, size distribution, surface modification and drug interaction. To describe the liposomes, different analytical techniques were used. In this paper, we reviewed the application of the atomic force microscopy (AFM), one of the most commonly applied scanning probe microscopy (SPM) techniques, in the description of liposome. The advantages and limitations of these techniques are discussed comparing the reported data with those referred to other well-know microscopical and spectroscopical techniques such as trasmission electron microscopy (TEM) and photon correlation spectroscopy (PCS). A detailed description of the application of AFM to evaluate the formation and the geometry of liposomes/DNA complexes is presented

PLA-microparticles formulated by means a thermoreversible gel able to modify protein encapsulation and release without being co-encapsulated

The aim of this work was to develop a novel strategy for the formulation of biodegradable PLA microspheres as delivery systems for proteins or peptides. The strategy is based on the exploitation of the gel-sol transition of the thermoreversible Pluronic F127 gel. The gel allows the formation of the particles without be co-entrapped in the matrix. The microspheres prepared using the novel technique (TG-Ms, or thermoreversible gel-method microspheres) were characterized in vitro (as concerns the size, the morphology, the protein encapsulation, the release and the protein distribution in the polymer matrix), in comparison with microspheres prepared using the classical double emulsion/solvent evaporation method (w/o/w-Ms). Two types of bovine serum albumin (BSA), with different water solubility, were used as model proteins. TG-Ms exhibited small size (7-50 m) and high protein content (8.6%, w/w) regardless of the BSA water solubility, in contrast with w/o/w-Ms, which revealed a size range of 100-130 mu m and a protein content related to the BSA water solubility. TG-Ms, in spite of their smaller size respect of the w/o/w-Ms, displayed a reduced initial burst effect and a higher rate in the second release phase that resulted in a quasi-constant profile. The release behavior of the TG-Ms may be attributable to both the localization of the protein in the particle core, as shown by the confocal laser scanning microscopy analysis on labeled-BSA loaded microspheres, and the few pores in the matrix, as shown by the scanning electron microscopy. A working hypothesis about the mechanism of the particle formation was also discussed. (c) 2006 Elsevier B.V. All. rights reserved

Characterization of cationic SLN/protamine complex as a non-viral transfer vector

Characterization of cationic SLN/protamine complex as a non-viral transfer vecto