431 research outputs found
Crystallographic orientation and grain size data obtained by Electron Back Scatter Diffraction (EBSD) on quartz analysed in mylonitic quartzite from the Island of Elba (Italy)
Raw Electron Back Scatter Diffraction (EBSD) data on deformed quartz from a mylonitic quartzite sample of the Calamita Schists (Island of Elba, Italy) is available at https://doi.org/10.17632/8c937t6zs4.32. The investigated sample (IESP3SP78) was collected in quartz-rich outcrops exposed at the Praticciolo Cape and was used to realize an oriented thin section (cut parallel to lineation and perpendicular to foliation). Preliminary investigations were carried out by transmitted-light and scanning electron microscopy (SEM), in order to select key areas for EBSD analysis. EBSD mapping was performed on selected areas of deformed quartz, which was the only phase indexed and were processed to derive orientation maps, pole figures, inverse pole figures, misorientation axis distribution in sample and crystal coordinates. While the processed data is available on the original research article (âFluid-assisted Strain Localization in Quartz at the Brittle/Ductile Transitionâ; https://doi.org/10.1029/2019GC008270), this contribution is devoted to supply the unprocessed EBSD data, together with a methodological description, aimed to allow the reproduction of the processed dataset. A brief statistical description of the investigated EBSD maps is also available. This data is valuable because it offers grain size and orientation analysis of deformed quartz investigated in a natural study case and the present publication makes it accessible to those working on naturally and experimentally deformed quartz
New Insights on Mechanical Stimulation of Mesenchymal Stem Cells for Cartilage Regeneration
Successful tissue regeneration therapies require further understanding of the environment in which the cells are destined to be set. The aim is to structure approaches that aspire to a holistic view of biological systems and to scientific reliability. Mesenchymal stem cells represent a valuable resource for cartilage tissue engineering, due to their chondrogenic differentiation capacity. Promoting chondrogenesis, not only by growth factors but also by exogenous enhancers such as biomechanics, represents a technical enhancement. Tribological evaluation of the articular joint has demonstrated how mechanical stimuli play a pivotal role in cartilage repair and participate in the homeostasis of this tissue. Loading stresses, physiologically experienced by chondrocytes, can upregulate the production of proteins like glycosaminoglycan or collagen, fundamental for articular wellness, as well as promote and preserve cell viability. Therefore, there is a rising interest in the development of bioreactor devices that impose compression, shear stress, and hydrostatic pressure on stem cells. This strategy aims to mimic chondrogenesis and overcome complications like hypertrophic phenotyping and inappropriate mechanical features. This review will analyze the dynamics inside the joint, the natural stimuli experienced by the chondrocytes, and how the biomechanical stimuli can be applied to a stem cell culture in order to induce chondrogenesis
Late Visean mylonitic granitoids in the Argentera Massif (western Alps, Italy): age and kinematic constraints on the FerriĂšreâMolliĂšres shear zone
ADAM10 Localization in Temporomandibular Joint Disk with Internal Derangement: An Ex Vivo Immunohistochemical Study
The purpose of this study was to determine the presence of ADAM10 in temporomandibular joint disk with internal derangement. Twenty-five paraffin blocks of displaced temporomandibular joint (TMJ) disk specimens from earlier investigations were retrieved from the archives of the University of Catania. Of these 16 had been removed from females and 9 from males; 11 with anterior disk displacement with reduction (ADDwR) and 14 with anterior disk displacement without reduction (ADDwoR). The sections were dehydrated, embedded in paraffin and cut. Then they were incubated in 0.3% H2O2/methanol and half of sections from each sample were incubated in diluted rabbit polyclonal anti-ADAM10 antibody. Then biotinylated anti-mouse/anti-rabbit IgG was applied to the sections, followed by avidinâbiotinâperioxidase complex. The results were analyzed and the results were that ADAM10 was overexpressed in the posterior band of sections from patients with ADDwR compared to the other bands of both ADDwR and ADDwoR sections. Overexpression correlated with severe histopathological degeneration. We believe these results have the potential to provide insights into the pathogenesis of TMJ disk degeneration and to help design new therapeutic approaches targeting the proteolytic events that lead to tissue degeneration. Early therapeutic block of ADAM10 activity could succeed in limiting aggrecan-rich matrix breakdown without affecting normal physiology
Fluid transfer and vein thickness distribution in high and low temperature hydrothermal systems at shallow crustal level in southern Tuscany (Italy)
Geometric analysis of vein systems hosted in upper crustal rocks and developed in high and low temperature hydrothermal systems is presented. The high temperature hydrothermal system consists of tourmaline-rich veins hosted within the contact aureole of the upper Miocene Porto Azzurro pluton in the eastern Elba Island. The low temperature hydrothermal system consists of calcite-rich veins hosted within the Oligocene sandstones of the Tuscan Nappe, exposed along the coast in southern Tuscany. Vein thickness distribution is here used as proxy for inferring some hydraulic properties (transmissivity) of the fluid circulation at the time of veinsâ formation. We derive estimations of average thickness of veins by using the observed distributions. In the case of power law thickness distributions, the lower the scaling exponent of the distribution the higher the overall transmissivity. Indeed, power law distributions characterized by high scaling exponents have transmissivity three order of magnitude lower than negative exponential thickness distribution. Simple observations of vein thickness may thus provides some clues on the transmissivity in hydrothermal systems
Caseous calcification of the mitral annulus with mitral regurgitation and impairment of functional capacity: a case report
<p>Abstract</p> <p>Introduction</p> <p>Mitral annular calcification is a common echocardiographic finding, especially in the elderly. Caseous calcification of the mitral annulus, however, is a relatively rare variant, having an echocardiographic prevalence of 0.6% in patients with mitral annular calcification. Caseous calcification needs to be differentiated from infected mitral annular calcification, mitral annular abscess and tumours. It is not malignant, and medical therapy with clinical follow-up is the therapeutic option. Surgery should be reserved for co-existent mitral valve dysfunction.</p> <p>Case presentation</p> <p>We report the case of a 69-year-old woman, in whom caseous calcification of the mitral annulus was found at transthoracic echocardiography. Cardiac surgery was performed because of significant mitral regurgitation and impairment of functional capacity.</p> <p>Conclusion</p> <p>Caseous calcification of the mitral annulus needs to be considered and confirmed by transthoracic echocardiography since there is potential for diagnostic confusion or misdiagnosis. This lesion appears to have a benign prognosis but, when associated with mitral valve dysfunction, cardiac surgery appears to be the best therapeutic option.</p
Random wave run-up with a physically-based Lagrangian shoreline model
n the present paper the run-up of random waves was calculated by means of a numerical method. In situ measurements based on a video imaging technique have been used for the validation of the present numerical model. The on-site run-up measurements have been carried out at Lido Signorino beach, near Marsala, Italy,along a transect, normal to the shore. A video camera and a linear array of rods have been used to obtain field data. Numerical simulations with a 1DH Boussinesq-type of model for breaking waves which takes into account the wave run-up by means of a Lagrangian shoreline model have been carried out. In such simulations random waves of given spectrum have been propagated in a numerical flume having the same beach slope of the measured transect. The comparison between registered and estimated run-up underlined an acceptable agreement. Indeed, the numerical model tends to underestimate the actual R2%, with the maximum underestimate being less than 24%, which is a reasonable error in many cases of engineering interest
Garnetârich veins in an ultrabasic amphibolite from NE Sardinia, Italy: An example of vein mineralogical reâequilibration during the exhumation of a granulite terrane
A complex system of monoâ and polymineralic centimeterâthick veins occurs within the
ultrabasic amphibolites of Montigiu Nieddu hill in northeastern Sardinia, and they are filled with garnet, amphibole, chlorite, and epidote. Some garnetârich veins are margined by an amphibole layer at the interface with the host rock and/or show replacement of epidote concentrated in the vein core. Together with homogeneous matrix garnet (Grt1), millimetric, euhedral, and strongly zoned garnet porphyroblasts occur within these veins. The estimated pressureâtemperature conditions (P = 1.0â1.7 GPa, T = 650â750 °C) for the formation of Grt1 match the metamorphic peak and early exhumation derived previously for the host rocks and confirm that the garnet veins also formed under highâpressure (HP) conditions. The igneous protolith of the host rocks experienced HP metamorphism in a subduction zone and underwent exhumation in an exhumation channel. The vein system in the ultrabasic amphibolites formed by cyclic hydrofracturing as rapid and transient events such as crackâseal veining. The growth of multiple veinâfilling mineral assemblages indicates the formation of separate veinâproducing cycles
The Cotoncello Shear Zone (Elba Island, Italy): The deep root of a fossil oceanic detachment fault in the Ligurian ophiolites
The ophiolite sequences in the western Elba Island are classically interpreted as a well-exposed ocean-floor section
emplaced during the Apennines orogeny at the top of the tectonic nappe-stack. Stratigraphic, petrological and geochemical
features indicate that these ophiolite sequences are remnants of slow-ultraslow spreading oceanic lithosphere
analogous to the present-day Mid-Atlantic Ridge and Southwest Indian Ridge.
Within the oceanward section of Tethyan lithosphere exposed in the Elba Island,we investigated for the first time
a 10s of meters-thick structure, the Cotoncello Shear Zone (CSZ), that records high-temperature ductile deformation.
We used a multidisciplinary approach to document the tectono-metamorphic evolution of the shear zone
and its role during spreading of the western Tethys. In addition, we used zircon UâPb ages to date formation of
the gabbroic lower crust in this sector of the Apennines. Our results indicate that the CSZ rooted below the
brittleâductile transition at temperature above 800 °C. A high-temperature ductile fabric was overprinted by fabrics
recorded during progressive exhumation up to shallower levers under temperature b500 °C.Wesuggest that
the CSZ may represent the deep root of a detachment fault that accomplished exhumation of an ancient oceanic
core complex (OCC) in between two stages of magmatic accretion.We suggest that the CSZ represents an excellent
on-land example enabling to assess relationships between magmatism and deformation when extensional
oceanic detachments are at work
An isolated anterior mitral leaflet cleft: a case report
<p>Abstract</p> <p>Introduction</p> <p>The anterior mitral leaflet cleft is an unusual congenital lesion most often encountered in association with other congenital heart defects. The isolated anterior leaflet cleft is quite a rare anomaly and is usually cause of mitral valve regurgitation. The importance of the lesion is that it is often correctable. When feasible, cleft suture and, eventually, annuloplasty are preferable to valve replacement. Echocardiography is the first choice technique in the evaluation of mitral valve disease, providing useful information about valve anatomy and hemodynamic parameters.</p> <p>Case presentation</p> <p>We present a case of an isolated anterior mitral leaflet cleft producing moderate-severe mitral regurgitation correctly identified by echocardiography and successfully surgically corrected.</p> <p>Conclusion</p> <p>Isolated cleft is a rare aberration, that has to be known in order to be diagnosed. Transthoracic and transesophageal echocardiography is the most useful non invasive technique for cleft diagnosis and to indicate the right surgical correction.</p
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