Search results for "valve"
showing 10 items of 576 documents
The Endothelial Transcription Factor ERG Mediates a Differential Role in the Aneurysmatic Ascending Aorta with Bicuspid or Tricuspid Aorta Valve: A P…
2022
The pathobiology of ascending aorta aneurysms (AAA) onset and progression is not well understood and only partially characterized. AAA are also complicated in case of bicuspid aorta valve (BAV) anatomy. There is emerging evidence about the crucial role of endothelium-related pathways, which show in AAA an altered expression and function. Here, we examined the involvement of ERG-related pathways in the differential progression of disease in aortic tissues from patients having a BAV or tricuspid aorta valve (TAV) with or without AAA. Our findings identified ERG as a novel endothelial-specific regulator of TGF-β-SMAD, Notch, and NO pathways, by modulating a differential fibrotic or calcified A…
Impact of Aortic Diameter Measurements at Three Anatomical Landmarks on Left Ventricular Output Calculation in Neonates
2021
OBJECTIVES To assess reproducibility and accuracy of left ventricular output (LVO) quantifications in neonates, when left ventricular outflow tract diameter (LVOTD) was measured at the hinges of the aortic valve (AV), at the aortic sinus (AS), and at the sinotubular junction (STJ). METHODS This was an observational study. In the first cohort of very preterm neonates, we assessed intraobserver and interobserver repeatability of LVOTD measured at the AV, AS, and STJ and of the corresponding LVO. In the second cohort of older neonates, we compared paired LVO measurements by echo and magnetic resonance imaging (MRI). RESULTS In the first cohort of 48 neonates, mean (standard deviation) weight a…
Optimal design of an electro-hydraulic valve for heavy-duty vehicle clutch actuator with certain constraints
2016
Abstract The main objective of this paper is to investigate the sensitivity analysis and optimal design of a proportional solenoid valve (PSV) operated pressure reducing valve (PRV) for heavy-duty automatic transmission clutch actuators. The nonlinear electro-hydraulic valve model is developed based on fluid dynamics. In order to implement the sensitivity analysis and optimization for the PRV, the PSV model is validated by comparing the results with data obtained from a real test-bench. The sensitivity of the PSV pressure response with regard to the structural parameters is investigated by using Sobol׳s method. Finally, simulations and experimental investigations are performed on the optimi…
State of the Art in Alq3-Based Spintronic Devices
2015
Since the first observation of a magnetoresistance signal in a vertical organic spin valve in 2004, tris (8-hydroxyquinoline) aluminium (Alq3) molecule has become a standard material for organic spintronics devices. This chapter will briefly present the state of the art on Alq3-based spintronic devices and the different approaches applied through the years to try to optimize these systems. It will be remarked that, despite extensively investigated, many fundamental questions regarding the spin injection and transport mechanisms through the organic layer are still unclear. The chapter will also present some of the most controversial topics in the organic spintronic area and it will highlight…
Orthotopic MAINZ pouch bladder substitution – long-term follow-up
2021
Introduction After radical cystectomy, orthotopic neobladder is one surgical strategy for urinary diversion. To assess the usefulness of an operation, long-term data are essential. We examined long-term complications and continence rates of orthotopic ileocecal (MAINZ pouch) bladder substitution. Material and methods Between 1986 and 2011, 193 patients underwent orthotopic MAINZ pouch bladder substitution. Until July 2000, ureter implantation was performed into the ascending colon through a submucosal tunnel technique (Goodwin-Hohenfellner). After July 2000, ureters were implanted into the terminal Ileum using the ileocecal valve to prevent reflux: the left spatulated ureter by an end-to-en…
Prognostic value of the ratio between prothesis area and indexed annulus area measured by multiSlice-CT for transcatheter aortic valve implantation p…
2016
Background Postprocedural aortic regurgitations following transcatheter aortic valve implantation (TAVI) procedures remain an is- sue. Benefit of oversizing strategies to prevent them isn’t well established. We compared different level of oversizing in our cohort of con- secutive patients to address if severe oversizing compared to normal sizing had an impact on post-procedural outcomes. Methods From January 2010 to August 2013, consecutive patients were referred for TAVI with preoperative Multislice-CT (MSCT) and the procedures were achieved using Edwards Sapien® or Corevalve devices®. Retrospectively, according to pre-procedural MSCT and the valve size, pa- tients were classified into thr…
Leukoma antiqua (Bivalvia) - A high-resolution marine paleoclimate archive for southern South America?
2018
The Patagonian Sea in the SW Atlantic is one of the most productive marine ecosystems worldwide. Besides its economic relevance, this shelf sea serves as a major sink for atmospheric CO2 and thus plays a major role in global climate. Despite that, the marine climate dynamics in that region remain barely known. Instrumental records only cover the last 30 years or so and high-resolution climate archives are currently not available. Here, we explore the possibility to obtain seasonally to inter-annually resolved paleotemperature data from shells of the bivalve mollusk, Leukoma antiqua collected alive from the shallow subtidal zone of the San Jorge Gulf. Results demonstrate that this species gr…
Unconventional application of Image Correlation techniques on Biomaterials and cardiovascular applications
2022
Image Correlation techniques are increasing in popularity and are now suitable to investigate complex structural and fluid-dynamics of cardiovascular systems. These approaches operate through a digital correlation of a pair of images to determine physical quantities of complex systems. In this thesis, their application to the mechanical characterisation of complex biomaterials (Nitinol and soft materials), and the characterisation of complex biofluid-dynamics was investigated, with the aim to analyse their reliability and enhance their accuracy and field of application. Digital Image Correlation, supported by Infrared Thermography, was used to achieve a more in depth understanding of the me…
Efficacy and safety of the pars plana clip in the Ahmed valve device inserted via the pars plana in patients with refractory glaucoma
2010
Manuel Diaz-Llopis1,2,3, David Salom1,3, Salvador García-Delpech1,2,3, Patricia Udaondo1,3, Jose Maria Millan3,5, J Fernando Arevalo61Department of Ophthalmology, La Fe University Hospital of Valencia, Valencia, Spain; 2Department of Ophthalmology of the Valencia University, Valencia, Spain; 3Biomedical Network Research Centre on Rare Diseases (CIBERER), Valencia, Spain; 4Catholic University San Vicente Martir, Valencia, Spain; 5Department of Genetics, La Fe University Hospital of Valencia, Valencia, Spain; 6Clinica Oftalmologica Centro Caracas, Retina and VItreous Service, Caracas, DC, VenezuelaPurpose: To evaluate the efficacy and safety of the pars plana clip (PPC) in the Ahme…
Abstracts of the 3rd Joint Meeting of Pathology and Laboratory Medicine
2016
Background: Degenerative forms of mitral valve diseases (MVDs) are complex pathologies. Thus, it is difficult to make generalizations about MVD pathways or genetic risk factors. However, a key role of metalloproteinases (MMPs) in their pathophysiology is emerging. Thus, we performed a study to assess eventual associations of some functional SNPs in MMP-2 and MMP-9 genes with MVD risk, symptom severity and short- and long-term (4.8 years) complications. Methods: For this purpose, 90 patients and two control groups were genotyped for MMP-2 and MMP-9 gene SNPs, and systemic levels of proatrial natriuretic peptide (ANP), and two enzymes were quantified and correlated to the MMP-2 and MMP-9 SNPs…