Search results for "valve"
showing 10 items of 576 documents
Climate variation during the Holocene influenced the skeletal properties of Chamelea gallina shells in the North Adriatic Sea (Italy)
2021
Understanding how marine taxa will respond to near-future climate changes is one of the main challenges for management of coastal ecosystem services. Ecological studies that investigate relationships between the environment and shell properties of commercially important marine species are commonly restricted to latitudinal gradients or small-scale laboratory experiments. This paper aimed to explore the variations in shell features and growth of the edible bivalve Chamelea gallina from the Holocene sedimentary succession to present-day thanatocoenosis of the Po Plain-Adriatic Sea system (Italy). Comparing the Holocene sub-fossil record to modern thanatocoenoses allowed obtaining an insight o…
Multi-isotopic and trace element evidence against different formation pathways for oyster microstructures
2021
Geochimica et cosmochimica acta 308, 326-352 (2021). doi:10.1016/j.gca.2021.06.012
Effect of Physiologic Oscillatory Fluid Shear Stress on Engineered Heart Valve Tissue Formation.
2010
It was previously demonstrated that combined flexure and flow in vitro conditioning augments engineered heart valve tissue formation using bone marrow-derived mesenchymal stem cells (MSC) seeded on polyglycolic acid (PGA)/poly-L-lactic acid (PLLA) blend nonwoven fibrous scaffolds (Engelmayr, et al., Biomaterials 2006; vol. 27 pp. 6083-95). Additionally, seeded scaffolds incorporated into a tissue engineered valve construct experienced significant increases in tissue formation rates with media supplementation (basic fibroblast growth factor [bFGF] and ascorbic acid-2-phosphate [AA2P]) and dynamic conditioning approximating pulmonary valve levels (Ramaswamy, et al., Biomaterials 2010; vol. 31…
GIV noroviruses and other enteric viruses in bivalves
2011
The impact of sewage discharge on the microbiological quality of shellfish is well known. Bivalves filter large volumes of water as part of their feeding activities, and thus accumulate and concentrate different types of pathogens from human fecal pollution. The aim of the study was to evaluate the presence, in these molluscs, of six different groups of enteric viruses: norovirus (genogroups I, II, and GIV), adenovirus, enterovirus, astrovirus, hepatitis A virus, and hepatitis E virus. The present study is the first to document the presence of GIV noroviruses in shellfish.
Effects of BDE-47 exposure on immune-related parameters of Mytilus galloprovincialis.
2019
Abstract The persistent pollutants polybrominated diphenyl ethers (PBDEs) have been demonstrated to produce several negative effects on marine organisms. Although Mytilus galloprovincialis was extensively studied as model system, the effects of PBDEs on the innate immune system of mussels remains unclear. In this study, except for the control treatment, specimens of M. galloprovincialis were fed with microalgae treated with increasing concentrations of PBDEs (maximum level 100 ng L−1 of BDE-47 per day). BDE-47 treatment was maintained for 15 days and then the animals were fed with the same control diet, without contaminants, for 15 days. Samples of haemolymph (HL) were obtained at T0, T15 a…
La lumachelle à Cardinia (Bivalves) et Alsatites (Ammonites) du " Revers de Côte Dure " dans l'Hettangien de la couverture sédimentaire du Massif du …
2011
29 pages; International audience; Ce travail est consacré à l'étude d'une faune de l'Hettangien moyen (Chronozone à Liassicus, Sous-Chronozone à Laqueus) qui, relativement peu diversifiée, mais très abondante et bien préservée, caractérise un niveau lumachellique spectaculaire dans la série du Jurassique inférieur, globalement peu fossilifère, de la couverture sédimentaire, du massif du Rochail (Bassin subalpin, zone dauphinoise). Cette faune, qui provient du Revers de Côte Dure (Villard-Notre-Dame, Isère, France), est essentiellement composée de bivalves (e.g., Cardinia, " Astarte ") et d'ammonites (e.g., Alsatites, Saxoceras), mais elle livre aussi, surtout au sommet du banc lumachellique…
Expression of endothelial cell adhesion molecules on heart valves: up-regulation in degeneration as well as acute endocarditis
2000
Inflammatory cytokines such as interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-alpha), as well as shear stress, cause endothelial cells (ECs), to undergo not only functional alterations but also structural reorganizations, which contribute to vascular leakage. Like ECs of the human aorta, ECs on heart valves are exposed to extreme shear stress. However, while ECs expression of cell adhesion molecules (CAMs) in large vessels has been widely studied, it seems that there are no such studies on ECs of heart valves, although this knowledge might be important for our understanding of the aetiological aspects of local inflammatory responses. Using immunohistochemistry, this study charac…
Giant Magnetoresistance (GMR) Magnetometers
2016
Since its discovering in 1988, the Giant Magnetoresistance (GMR) effect has been widely studied both from the theoretical and the applications points of view. Its rapid development was initially promoted by their extensive use in the read heads of the massive data magnetic storage systems, in the digital world. Since then, novel proposals as basic solid state magnetic sensors have been continuously appearing. Due to their high sensitivity, small size and compatibility with standard CMOS technologies, they have become the preferred choice in scenarios traditionally occupied by Hall sensors. In this chapter, we analyze the main properties of GMR sensors regarding their use as magnetometers. W…
Effects of sample pretreatment and external contamination on bivalve shell and Carrara marble δ18O and δ13C signatures
2017
Abstract Stable isotope signatures of bivalve shells serve as important paleoclimate proxies. However, such data can be biased as a consequence of physical and chemical sample pretreatment and contamination during sampling. As yet, the potential isotope error induced by paleontological preservation techniques and specific methods used in bivalve sclerochronology have not been systematically assessed. To address these issues, homogenized powder of a well-preserved, aragonitic fossil shell, Glycymeris obovata (ca. 30 Ma old) as well as Carrara marble powder (calcite) were exposed to ultrasound, a set of different staining solutions and cleaning agents. In addition, these reference materials w…
Computed tomography imaging needs for novel transcatheter tricuspid valve repair and replacement therapies
2020
Abstract Transcatheter tricuspid valve therapies are an emerging field in structural heart interventions due to the rising number of patients with severe tricuspid regurgitation and the high risk for surgical treatment. Computed tomography (CT) allows exact measurements of the annular plane, evaluation of adjacent structures, assessment of the access route, and can also be used to identify optimal fluoroscopic projection planes to enhance periprocedural imaging. This review provides an overview of current transcatheter tricuspid valve repair and replacement therapies and to what extent CT can support these interventions.