High-resolution geoelectrical characterization and monitoring of natural fluids emission systems to understand possible gas leakages from geological carbon storage reservoirs.

Gas leakage from deep geologic storage formations to the Earth's surface is one of the main hazards in geological carbon sequestration and storage. Permeable sediment covers together with natural pathways, such as faults and/or fracture systems, are the main factors controlling surface leakages. Therefore, the characterization of natural systems, where large amounts of natural gases are released, can be helpful for understanding the effects of potential gas leaks from carbon dioxide storage systems. In this framework, we propose a combined use of high-resolution geoelectrical investigations (i.e. resistivity tomography and self-potential surveys) for reconstructing shallow buried fracture networks in the caprock and detecting preferential gas migration pathways before it enters the atmosphere. Such methodologies appear to be among the most suitable for the research purposes because of the strong dependence of the electrical properties of water-bearing permeable rock, or unconsolidated materials, on many factors relevant to CO2 storage (i.e. porosity, fracturing, water saturation, etc.). The effectiveness of the suggested geoelectrical approach is tested in an area of natural gas degassing (mainly CH4) located in the active fault zone of the Bolle della Malvizza (Southern Apennines, Italy), which could represent a natural analogue of gas storage sites due to the significant thicknesses (hundreds of meters) of impermeable rock (caprock) that is generally required to prevent carbon dioxide stored at depth from rising to the surface. The obtained 3D geophysical model, validated by the good correlation with geochemical data acquired in the study area and the available geological information, provided a structural and physical characterization of the investigated subsurface volume. Moreover, the time variations of the observed geophysical parameters allowed the identification of possible migration pathways of fluids to the surface.

Essential Nanostructure Parameters to Govern Reinforcement and Functionality of Poly(lactic) Acid Nanocomposites with Graphene and Carbon Nanotubes for 3D Printing Application.

Poly(lactic) acid nanocomposites filled with graphene nanoplatelets (GNPs) and multiwall carbon nanotubes (MWCNTs) are studied, varying the filler size, shape, and content within 1.5-12 wt.%. The effects of the intrinsic characteristics of nanofillers and structural organization of nanocomposites on mechanical, electrical, thermal, and electromagnetic properties enhancement are investigated. Three essential rheological parameters are identified, which determine rheology-structure-property relations in nanocomposites: the degree of dispersion, percolation threshold, and interfacial interactions. Above the percolation threshold, depending on the degree of dispersion, three structural organizations are observed in nanocomposites: homogeneous network (MWCNTs), segregated network (MWCNTs), and aggregated structure (GNPs). The rheological and structural parameters depend strongly on the type, size, shape, specific surface area, and functionalization of the fillers. Consequently, the homogeneous and segregated network structures resulted in a significant enhancement of tensile mechanical properties and a very low electrical percolation threshold, in contrast to the aggregated structure. The high filler density in the polymer and the low number of graphite walls in MWCNTs are found to be determinant for the remarkable shielding efficiency (close to 100%) of nanocomposites. Moreover, the 2D shaped GNPs predominantly enhance the thermal conductivity compared to the 1D shaped MWCNTs. The proposed essential structural parameters may be successfully used for the design of polymer nanocomposites with enhanced multifunctional properties for 3D printing applications.

Morphological, Rheological and Electromagnetic Properties of Nanocarbon/Poly(lactic) Acid for 3D Printing: Solution Blending vs. Melt Mixing.

The limitation of poor mechanical stability and difficulties in printing electrically conductive components can be overcome owing to the recent introduction of nanotechnology into the field of additive manufacturing (AM) and the consequent development of nonconventional polymer nanocomposites suitable for 3D printing. In the present work, different weight percentages (up to 6 wt % in total) of carbon-based nanostructures-multiwalled carbon nanotubes (MWCNTs), graphene nanoplatelets (GNPs), and a combination of both fillers (MWCNTs/GNPs)-were incorporated into poly(lactic) acid (PLA, Ingeo™) in an attempt to overcome several limitations of conventional 3D manufacturing based on insulating materials. Solution blending and melt mixing were the two fabrication methods adopted for preparation of the samples under test. A comparison of the morphological, rheological, and electrical properties of the resulting nanocomposites was carried out. Moreover, for the same weight concentrations, the influence of physical and geometrical features (i.e., functionalization and aspect ratio) of the embedded fillers was also investigated. Rheological methods were applied to control the quality of fillers dispersion in PLA matrix. The rheological percolation threshold was considered as reference in order to evaluate the internal structure of nanodispersions. TEM visualization, combined with rheological characterizations, was used for efficient control of the nanofiller dispersion. DC characterization revealed that lower electrical percolation thresholds and higher values of electrical conductivity were achieved using fillers with a larger aspect ratio and melt mixing, respectively. Moreover, given the possibility of obtaining complex and appropriate shapes for electromagnetic compatibility (EC) applications, electromagnetic (EM) response of the nanocomposites at the highest filler concentration was investigated in GHz and THz regions. It was found that the electromagnetic shielding efficiency (EMI) of nanocomposites strongly depended on the aspect ratio of the nanofillers, whereas the type of processing technique did not have a significant effect. Therefore, a careful choice of methods and materials must be made to address the final application for which these materials and further 3D printed architectures are designed.

Dermatofibroma looks dermoscopically different on trunk versus extremities.

BACKGROUND: Several dermoscopic patterns have been described in dermatofibroma (DF), but little is known about morphologic features of DF in different anatomic locations. The aim of this study was to evaluate the association between the dermoscopic pattern of DF and the anatomic location. METHODS: We conducted a retrospective observational study of 169 DF that were evaluated for the presence of dermoscopic structures and patterns. Patients' age and sex were recorded, while the anatomic location of each lesion was categorized in 2 main groups, namely extremities and trunk. The possible correlation between the dermoscopic pattern and the anatomic site was tested using the χ2 test or the Fisher's exact test, as appropriate. RESULTS: DFs resulted mainly located on extremities as compared to trunk (79.2% and 20.7%, respectively). Frequencies of dermoscopic patterns of DF were the following: atypical (26.6%), network and patch (23.7%), total structureless (17.1%), structureless and patch (9.5%), total network (6.5%), network and structureless (3.5%), double network (2.9%), white network and total structureless (2.9%), white network (2.9%), multifocal patches (2.4%), and total patch (1.8%). A significant association between network and patch pattern and extremities (27.6%) was found (P<0.05). Similarly structureless and patch pattern resulted completely absent on trunk and quite frequent on extremities (11.9%; P<0.05). In contrast, total structureless was the most common pattern on the trunk (31.4%) and less represented on extremities (P<0.05). Total network pattern followed the same trend (P<0.05). CONCLUSIONS: Our study reveals that the dermoscopic pattern of DF is significantly influenced by the anatomic location of the lesion. The "classic" pattern with a white patch surrounded by network dermoscopically characterizes DFs of the extremities, while DFs located on the trunk often exhibit different findings.

Radiation dermatitis, burns, and recall phenomena: Meaningful instances of immunocompromised district.

Ionizing and ultraviolet radiations, as well as burns, can selectively damage and immunologically mark the cutaneous area they act on through direct and indirect mechanisms. After the causal event has disappeared, the affected skin district may appear clinically normal, but its immune behavior is often compromised forever. In fact, irradiated or burned skin areas undergo a destabilization of the immune control, which can lead to either a reduction of immunity (as suggested by the facilitated local occurrence of tumors and infections) or an excess of it (as suggested by the possible local onset of disorders with exaggerated immune response). In other words, these areas become typical immunocompromised districts (ICD). Also, in recall phenomena the damaged skin area usually behaves as an ICD with an exaggerated immune response toward a wide range of drugs (especially chemotherapeutic agents) that prove to be harmless on the undamaged skin surface. The occurrence of any skin disorder on an irradiated, photoexposed, or burned skin area can be defined as an isoradiotopic, isophototopic, or isocaumatopic response, respectively; however, the opposite may also occur when elsewhere generalized cutaneous diseases or eruptions selectively spare irradiated, photoexposed, or burned skin sites (isoradiotopic, isophototopic, and isocaumatopic nonresponse, respectively). The pathomechanisms involved in any secondary disorder occurring on irradiated or burned skin areas may be linked to locally decreased or altered lymph flow (with dysfunction of lymph drainage) on the one hand, and to fibrotic throttling or reduction of peptidergic nerve fibers (with dysfunction of neuroimmune signaling) on the other hand, resulting in a significant dysregulation of the local immune response. Future clinical observations and experimental investigations on radiation dermatitis, sunburns, and thermal or chemical skin injuries should shed new light on the mechanisms regulating regional resistance to infectious agents, local oncogenesis, and district propensity to dysimmune reactions.