Search results for " wedge"
showing 7 items of 97 documents
Tectono-Magmatic Evolution, Age and Emplacement of the Agardagh Tes-Chem Ophiolite in Tuva, Central Asia: Crustal Growth by Island arc Accretion
2004
Publisher Summary The Agardagh Tes–Chem ophiolite in Tuva, Central Asia, is part of the Central Asian Mobile Belt which formed during subduction–accretion processes lasting from the early Neoproterozoic to the late Palaeozoic. The Agardagh Tes–Chem ophiolite marks the northwestern border of the Tuva–Mongolian Massif (TMM), which comprises several intrusive and metamorphic complexes. These complexes consist of metatonalites, gneisses, migmatites, amphibolites, marbles, quartzites, low-grade metasedimentary rocks and minor ultramafic lenses, and radiometric ages range between 536 and 464 Ma. Field observations suggest that the southwestern part of the Tes–Chem unit represents the lower to int…
Recycling and transport of continental material through the mantle wedge above subduction zones: A Caribbean example
2016
Abstract Estimates of global growth rates of continental crust critically depend upon knowledge of the rate at which crustal material is delivered back into the mantle at subduction zones and is then returned to the crust as a component of mantle-derived magma. Quantification of crustal recycling by subduction-related magmatism relies on indirect chemical and isotopic tracers and is hindered by the large range of potential melt sources (e.g., subducted oceanic crust and overlying chemical and clastic sediment, sub-arc lithospheric mantle, arc crust), whose composition may not be accurately known. There is also uncertainty about how crustal material is transferred from subducted lithosphere …
Comparative tests on different multi-electrode arrays using models in near-surface geophysics
2008
In this paper, the response of different synthetic models to geoelectrical multi-electrode surveys is studied. The models considered are related to two main problems, which are very common in geophysical research regarding hydrogeology and engineering. The first class of models represents buried walls, similar archaeological remains or remains of buried foundations; the other class corresponds to a sea-water intrusion of a fresh water aquifer, which is generally studied in hydrogeophysics. A set of 2D simulations, starting from the synthetic models, was carried out to compare the behaviour of the different arrays when acquiring measurements of electrical resistivity tomography. For each mod…
Echocardiography to estimate high filling pressure in patients with heart failure and reduced ejection fraction
2020
Aims: Echocardiographic assessment of left ventricular filling pressures is performed using a multi-parametric algorithm. Unselected sample of patients with heart failure with reduced ejection fraction (HFrEF) patients may demonstrate an indeterminate status of diastolic indices making interpretation challenging. We sought to test improvement in the diagnostic accuracy of standard and strain echocardiography of the left ventricle and left atrium (LA) to estimate a pulmonary capillary wedge pressure (PCWP) > 15 mmHg in patients with HFrEF. Methods and results: Out of 82 consecutive patients, 78 patients were included in the final analysis and right heat catheterization, and echocardiogram…
Echocardiography in assessing acute pulmonary hypertension due to pulmonary embolism.
1980
Eighteen patients with acute pulmonary embolism were studied with right heart catheterization and M mode echocardiography. No patient had evidence of preexisting cardiopulmonary disease; pulmonary embolism was documented with pulmonary angiography. The mean pulmonary arterial pressure correlated with the angiographic severity index of embolic obstruction (r = 0.61, p 2 , p 2 ) and in 5 patients with acute pulmonary embolism and a mean normal pulmonary arterial pressure (10.9 ± 0.4 mm/m 2 ). For all measurements the index size of the right pulmonary artery correlated with the mean pulmonary arterial pressure (r = 0.84, p
Preliminary experience with lumbar facet distraction and fixation as treatment for lumbar spinal stenosis
2017
Objectives: To assess the properties of facet fixation with the Facet Wedge system in patients affected by lumbar spinal stenosis (LSS). Summary of Background Data: Implant of intra-articular spacers is an emerging technique for lumbar degenerative disease. Methods: This study included forty patients (Group 1) with symptomatic LSS in whom intra-articular spacers have been implanted along with microdecompression (MD) of the neural structures. Group 1 has been compared with a homogeneous group of patients with LSS treated with MD without intra-articular spacers implant (Group 2). Clinical findings have been observed preoperatively and 3, 6, 12 months postoperatively using dedicated questionna…
Preliminary Experience with a Novel System of Facet Fixation to Treat Patients with Lumbar Degenerative Disease. A New Perspective in Minimally Invas…
2017
Purpose We report our experience with a novel surgical device for the treatment of lumbar degenerative microinstability. Facet Wedge (DePuy Synthes, Raynham, Massachusetts, United States) is a novel technique of intra-articular lumbar facet fixation that provides a minimally invasive alternative to standard posterior fixation. Materials and Methods From November 2014 to July 2015, 38 patients underwent single-level Facet Wedge implantation. The main surgical indications included herniated disk (18 patients), spinal canal and foraminal stenosis (14 patients), and Meyerding grade I degenerative spondylolisthesis (6 patients). All the patients showed radiologic signs of microinstability: hype…