Studies on the Quercus hybrids in Sicily: leaf micromorphology and xylem structure in Quercus × fontanesii Guss.

In order to find new suitable characters in the taxonomic delimitation of the genus Quercus, whose hardness is well known, Quercus x fontanesii, endemic to Sicily, has been studied in comparison with its parents, i.e. Q. gussonei, wich is close to Q. cerris, and Q. suber. These taxa are here delimited as far as taxonomy, ecology, and Sicilian distribution are concerned. Furthermore, the results of SEM microstructure analysis of leaves and xylem anatomy are illustrated and commented. The analysis of the leaf microstructures shows that there is a remarkable similarity between the stomata and stellata trichomes of Q. x fontanesii and both the parental species, as the trichome rays are numerically intermediate in the nothotaxon. Also xylem anatomy in Q. x fontanesii results intermediate between both the parents. In particular, the qualitative analysis of the transverse sections on earlywood and latewood show that the vessel distribution in Q. xfontanesii gives origin to a structure with intermediate features between a diffuse porous wood (Q. suber) and a ring porous wood (Q. gussonei). The quantitative analysis, based on the maximum and minimum diameter, surface and shape factor, confirms the conclusion stated above. In particular, the minimum diameter of the wood vessels is the most significant parameter. The frequency distribution shows an increase in the number of vessels in Q. xfontanesii, from earlywood to latewood, differently from the two parental species

The essential oil compositions of three Sicilian accessions of Viscum album L. growing on three different host trees

Viscum album L., (Common Mistletoe), is a hemiparasitic shrub that lives on a wide range of woody plant species, known since Neolithic period for its ritual and for pharmacological properties. Up to now, no investigation has been reported on the chemical composition of the essential oils of V. album aerial parts in relation with the diverse host trees. Consequently, the essential oils compositions of three Sicilian accession of V. album, growing on Quercus suber L., Crataegus monogyna Jacq. and Olea europaea L. var. europaea cv. 'Santagatese', respectively, were evaluated by GC-MS. The three populations showed quite different profiles indicating that the nature of the host considerably influences the chemical composition of the guest plant, V. album

Rare malignant anomalous right coronary artery incidentally detected by dual source computed tomography angiography in an adult referred for transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is a safe treatment option for elderly patients with aortic stenosis (AS) with high or intermediate surgical risk. The anomalous origin of coronaries from a single Valsalva sinus has a higher risk of coronary obstruction during the TAVI procedure, so prior knowledge of these anatomical variants is of paramount importance as it can change the surgical strategy. In this report, we present the case of an adult patient suffering from severe aortic stenosis and incidentally diagnosed with an anomalous malignant variant of right coronary artery (RCA) by pre-procedural Computed Tomography (CT) Angiography. In TAVI planning, the use of electrocardiography (ECG) gated Dual Source CT (DSCT) enables accurate coronary and aorto-iliac vascular study, useful for detecting congenital coronary anomalies

Hydrating Cement Particle Interaction Model for Yield Stress Analysis

This study overviews existing methods for analyzing cement paste yield stress, and presents a new approach based on micro-structural computation. The proposed model explicitly considers cement particle interactions, both the colloidal and the nucleated gel ones. A new algorithm is proposed based on flocculating of poly-dispersed hard spheres in a simulation box, followed by nucleation of mono-sized nano-gel particles. The obtained virtual microstructures are than used as an input for a mechanical approach, which is conceptualized for simulating sliding kinematics needed to initiate the flow of the percolated solid network, i.e. to reach the paste yield stress. The microstructural modeling tool provides insights on how the localized gel is bridging the cement particles, responsible for the yield stress properties of bulk cement paste. Thus, it provides a promising new approach for quantifying the evolution of the bridging strength with nucleation (shear rest) time, enabling parametrization of the mechanical yield stress computation at micro-structural scale

The chemical composition of the aerial parts essential oil of Jacobaea delphiniifolia (Asteraceae) growing in Sicily (Italy)

Jacobaea is a small genus of plants belonging to Asteraceae family, formerly joint to Senecio genus, that includes more than 60 species and sub-species. Several taxa of this genus have been extensively studied both for their non-volatile and volatile metabolites. In the present study the chemical composition of the essential oil (EO) from aerial parts of Jacobaea delphiniifolia (Vahl) Pelser & Veldkamp, collected in Sicily, was analyzed by GC–MS. No one report has been previously published on the EO of this species. The result showed the presence of a large quantity of two metabolites, namely 1-undecene (63.57%) and thymol methyl ether (13.65%). Chemotaxonomic considerations were carried out by comparing the other oils of Jacobaea taxa studied so far

A mesoscale approach for modeling capillary water absorption and transport phenomena in cementitious materials

This paper proposes a mesoscale approach for simulating moisture transport by capillary action in partly-saturated porous cementitious composites. The modeling approach explicitly accounts for moisture transport through a mesostructure composed of coarse aggregates, surrounding cementitious mortar and interfaces. These latter, namely interface transition zones (ITZs), allow to describe the interaction between aggregates and mortar, and may cause an alternative path for the internal moisture movements. Basic morphology effects of the ITZs are simulated using a ribbon approach. Random spatial distribution of cement particles are stacked in the meso-geometry. Aggregate particles are introduced as randomly perturbed polygons and the moisture transport is modeled as a diffusion problem and solved by means of the finite element method. The proposed constitutive models are based on a proper description of the permeability and pore size distribution which strongly affect the local moisture content. Numerical results at both macro- and mesoscale levels demonstrate the soundness and capability of the proposed approach. The integrated modeling results actually demonstrate the potential of the mesoscale approach and shows the role of the ITZs as an internal interconnected network.Fil: Caggiano, Antonio. Universitat Technische Darmstadt; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Said Schicchi, Diego. Leibniz-Institut Für Werkstofforientierte Technologien; Alemania. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Mankel, Christoph. Universitat Technische Darmstadt; AlemaniaFil: Ukrainczyk, Neven. Universitat Technische Darmstadt; AlemaniaFil: Koenders, Eduardus A. B.. Universitat Technische Darmstadt; Alemani