Search Results
Results 1 - 50 of 1080
1 2 3 4 5 6 7 8 9 10 >
Spranger Katerina - - 2014
This paper presents a methodology for modeling the deployment of implantable devices used in minimally invasive vascular interventions. Motivated by the clinical need to perform preinterventional rehearsals of a stent deployment, we have developed methods enabling virtual device placement inside arteries, under the constraint of real-time application. This requirement of ...
Georgakarakos E E .Department of Vascular Surgery, "Democritus" Medical School, University Hospital of Alexandroupolis, Greece - - - 2014
The influence of the relative iliac limb length of an endograft (EG) on the displacements forces (DF) predisposing to adverse effects are underappreciated in the literature. Therefore, we conducted a computational study to estimate the magnitude of the DF acting over an entire reconstructed EG and its counterparts for a ...
Ni Xiao-Yu XY a School of Mechanical and Electronic Engineering, Nanjing Forestry University , Nanjing , Jiangsu Province 210037 , P.R. - - 2014
This paper discusses various issues relating to the mechanical properties of a braided non-vascular stent made of a Ni-Ti alloy. The design of the stent is a major factor which determines its reliability after implantation into a stenosed non-vascular cavity. This paper presents the effect of the main structural parameters ...
Hsiao Hao-Ming HM Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan, - - 2014
In recent years, interventional cardiologists have discussed over a new clinical issue called longitudinal stent compression (LSC), a failure mode not previously observed in coronary stents. This phenomenon occurs when the physician attempts to cross a deployed stent with a second device, causing the stent to dramatically shorten when two ...
Kolandaivelu Kumaran K Institute for Medical Engineering and Science, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02142, USA. Electronic address: - - 2014
Through decades of use and refinement, endovascular stents have become part and parcel of the management of obstructive atherosclerotic lesions. Upon stent placement, a variety of biophysical reactions ensue, governed not only by the mechanical and material properties of the device, but also the impact these properties have on the ...
Grogan J A JA Biomechanics Research Centre (BMEC), Mechanical and Biomedical Engineering, National University of Ireland, Galway. Electronic address: - - 2014
Absorbable metal stents (AMSs) are an emerging technology in the treatment of heart disease. Computational modelling of AMS performance will facilitate the development of this technology. In this study a physical corrosion model is developed for AMSs based on the finite element method and adaptive meshing. The model addresses a ...
Schmidt Michael M Institute for Biochemistry, University of Applied Sciences Mannheim, Mannheim, - - 2014
The separation of proteins by internally and externally generated pH gradients in chromatofocusing on ion-exchange columns is a well-established analytical method with a large number of applications. In this work, a stoichiometric displacement model was used to describe the retention behavior of lysozyme on SP Sepharose FF and a monoclonal ...
Hunter Kendall S KS Department of Bioengineering, University of Colorado Denver, Aurora, CO, - - 2014
Micro-invasive glaucoma surgery with the Glaukos iStent® or iStent inject® (Glaukos Corporation, Laguna Hills, CA, USA) is intended to create a bypass through the trabecular meshwork to Schlemm's canal to improve aqueous outflow through the natural physiologic pathway. While the iStent devices have been evaluated in ex vivo anterior segment ...
Curtin Antonia E AE Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of - - 2014
While animal models are widely used to investigate the development of restenosis in blood vessels following an intervention, computational models offer another means for investigating this phenomenon. A computational model of the response of a treated vessel would allow investigators to assess the effects of altering certain vessel- and stent-related ...
Faúndez Eduardo I EI Entomology Department, North Dakota State University, Dept. 7650, P.O. Box 6050; Fargo, ND.; Email: - - 2014
Cochabambia Marcuzzi (1985) (Coleoptera: Tenebrionidae) is a junior homonym of Cochabambia Pirán, 1959 (Hemiptera: Heteroptera: Acanthosomatidae). Allotriocochabambia is proposed as a new name for the tenebrionid genus, and as result Allotriocochabambia kulzeri (1985) is proposed as new combination. The placement of Cochabambia Pirán within the Acanthosomatidae is discussed. 
Gavrilets Sergey S From the Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996 (Gavrilets); the Department of Mathematics, University of Tennessee, Knoxville, TN 37996 (Gavrilets); and the National Institute for Mathematical and Biological Synthesis, University of Tennessee, Knoxville, TN 37996 (Gavrilets). - - 2014
Theory building is an integral part of biological research, in general, and of speciation research, in particular. Here, I review the modeling work on speciation done in the last 10 years or so, assessing the progress made and identifying areas where additional effort is required. Specific topics considered include evolutionary ...
Helbing Dirk D ETH Zurich - Swiss Federal Institute of Technology Zurich, Chair of Sociology, in particular of Modeling and Simulation, Zurich, Switzerland; Santa Fe Institute, Santa Fe, New Mexico, United States of - - 2014
Understanding norms is a key challenge in sociology. Nevertheless, there is a lack of dynamical models explaining how one of several possible behaviors is established as a norm and under what conditions. Analysing an agent-based model, we identify interesting parameter dependencies that imply when two behaviors will coexist or when ...
Murray Thomas A - - 2013
Trial investigators often have a primary interest in the estimation of the survival curve in a population for which there exists acceptable historical information from which to borrow strength. However, borrowing strength from a historical trial that is non-exchangeable with the current trial can result in biased conclusions. In this ...
Sandtner W - - 2013
Amphetamines bind to the plasmalemmal transporters for the monoamines dopamine (DAT), norepinephrine (NET) and serotonin (SERT); influx of amphetamine leads to efflux of substrates. Various models have been put forth to account for this amphetamine-induced reverse transport in mechanistic terms. A most notable example is the molecular stent hypothesis, which ...
Lee Joo Myung JM Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, - - 2013
Along with the development of innovative stent designs, preclinical trials in animal models are essential. Many animal models have been used and appear to yield comparable results to clinical trials despite substantial criticisms about their validity. Among the animal models, porcine coronary artery models have been the standard models for ...
Hyun Dongho - - 2013
The need for newer gastrointestinal (GI) stents has been continuously raised. Newly developed stents are generally tested for physical properties in vitro and directly introduced to clinical practice because there is no reliable animal model of GI obstruction. The aim of this study was to establish an animal model both that ...
Singh Charanpreet - - 2013
Stent-graft (SG) induced biomechanical mismatch at the aortic repair site forms the major reason behind postoperative hemodynamic complications. These complications arise from mismatched radial compliance and stiffness property of repair device relative to native aortic mechanics. The inability of an exoskeleton SG design (an externally stented rigid polyester graft) to ...
Sweeney Caoimhe A - - 2013
Fatigue of CoCr alloy stents has become a major concern in recent times, owing to cases of premature fracture, often driven by microstructural phenomena. This work presents the development of a micromechanical framework for fatigue design, based on experimental characterisation of a biomedical grade CoCr alloy, including both microscopy and ...
Zarogoulidis Paul - - 2013
Currently, interventional pulmonology has the tools for efficient de-bulking of tracheal stenosis, which can either be the result of cancer tissue or benign tissue growth inside the respiratory tract. There are additionally other situations, such as thracheomalece and fistula formation, which require stent placement for efficient support in the tract ...
Semmling Beatrice B Institute of Pharmacy, Center of Drug Absorption and Transport, University of Greifswald, Felix-Hausdorff-Straße 3, 17487, Greifswald, - - 2013
The vessel-simulating flow-through cell (vFTC) has been used to examine release and distribution from drug-eluting stents in an in vitro model adapted to the stent placement in vivo. The aim of this study was to examine the effect of the admixture of different hydrophobic additives to the vessel wall simulating ...
Suh Hae Sun - - 2013
The goal of this study was to perform an economic analysis of a primary stenting with drug-eluting stents (DES) compared with bare-metal stents (BMS) in patients with acute myocardial infarction (AMI) admitted through an emergency room (ER) visit in Korea using population-based data. We employed a cost-minimization method using a ...
Asberg Dennis - - 2013
The inverse method is a numeric method for fast estimation of adsorption isotherm parameters directly from overloaded elution profiles. However, it has previously only been used for isocratic experiments. Here we will extend the inverse method so it can be used for gradient elution too. This extended inverse method will ...
Janiga Gábor - - 2013
Abstract The number of scientific publications dealing with stented intracranial aneurysms is rapidly increasing. Powerful computational facilities are now available; an accurate computational modeling of hemodynamics in patient-specific configurations is, however, still being sought. Furthermore, there is still no general agreement on the quantities that should be computed and on ...
Pibouleau Leslie - - 2013
Objectives: The aim of this study was to propose a statistical model that takes into account clinical data on earlier versions when evaluating the latest version of an implantable medical device (IMD). Methods: We compared the performances of a Bayesian three-level hierarchical meta-analysis model with those of a Bayesian random-effects ...
Qiao Aike - - 2013
Different from the traditional stents, a novel stent with triangular wire cross-section is proposed, and numerical simulation is performed to compare the hemodynamic effect of the novel stent with that of traditional ones. Three kinds of stents with circular, rectangular, and triangular wire cross-sections were designed to treat saccular aneurysm, ...
Pham Thuy - - 2013
Recent clinical studies of the percutaneous transvenous mitral annuloplasty (PTMA) devices have shown a short-term reduction of mitral regurgitation after implantation. However, adverse events associated with the devices such as compression and perforation of vessel branches, device migration and fracture were reported. In this study, a finite element analysis was ...
Boyle Colin J - - 2013
Many cardiovascular diseases are characterised by the restriction of blood flow through arteries. Stents can be expanded within arteries to remove such restrictions; however, tissue in-growth into the stent can lead to restenosis. In order to predict the long-term efficacy of stenting, a mechanobiological model of the arterial tissue reaction ...
Steinheimer Jan J Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-Universität, Ruth-Moufang-Strasse 1, 60438 Frankfurt am Main, - - 2013
Recent LHC data on Pb+Pb reactions at sqrt[s]_{NN}=2.7  TeV suggests that the p/π is incompatible with thermal models. We explore several hadron ratios (K/π, p/π, Λ/π, Ξ/π) within a hydrodynamic model with a hadronic after burner, namely the ultrarelativistic quantum molecular dynamics model 3.3, and show that the deviations can be ...
Grogan J A - - 2013
The dimensions of coronary stent struts are similar to those of the metallic grains of their constituent alloys. This means that statistical size effects (SSEs), which are evident in polycrystals with few grains through their dimensions, can have detrimental effects on the mechanical performance of stent struts undergoing large plastic ...
Karvounis E C - - 2013
With an ever increasing number of biological models available on the internet, a standardized modelling framework is required to allow information to be accessed and visualized. In this paper we propose a novel Extensible Markup Language (XML) based format called ART-ML that aims at supporting the interoperability and the reuse ...
Li Hongxia - - 2013
This paper presents an effective optimization method using the Kriging surrogate model combing with modified rectangular grid sampling to reduce the stent dogboning effect in the expansion process. An infilling sampling criterion named expected improvement (EI) is used to balance local and global searches in the optimization iteration. Four commonly ...
Moiseyev Gilead - - 2012
In this review, we examine the possibility of using the computational modeling of hemodynamically-induced thrombosis as an engineering tool for designing vascular implants such as stents, grafts and artificial valves, and procedures such as aneurysm coiling and vascular grafting. The success or failure of such procedures depends strongly on how ...
Wu Wei - - 2012
Biodegradable magnesium alloy stents (MAS) constitute a promising candidate which might present improved long-term clinical performances over commercial bare metal or drug eluting stents. However, MAS were found to show limited mechanical support for diseased vessels due to fast degradation. Optimizing stent designs through finite element analysis (FEA) is an ...
Rohrich Rod J RJ Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9132, USA. - - 2012
Excess infratip lobule projection is often the result of deformities of the middle crus and lower lateral cartilage. The causes and correction of excess projection have not been well described. The classification of the deformities causing excess infratip lobule projection is defined and a surgical algorithm for addressing the infratip ...
Morlacchi Stefano - - 2012
In the last two decades, numerical models have become well-recognized and widely adopted tools to investigate stenting procedures. Due to limited computational resources and modeling capabilities, early numerical studies only involved simplified cases and idealized stented arteries. Nowadays, increased computational power allows for numerical models to meet clinical needs and ...
De Cock Erwin - - 2012
PURPOSE: The Zilver PTX drug-eluting stent (Cook Ireland Ltd., Limerick, Ireland) represents an advance in endovascular treatments for atherosclerotic superficial femoral artery (SFA) disease. Clinical data demonstrate improved clinical outcomes compared to bare-metal stents (BMS). This analysis assessed the likely impact on the French public health care budget of introducing ...
Manojlovic Dragica - - 2012
Elution of potentially toxic substances, including monomers, from resin-based dental composites may affect the biocompatibility of these materials in clinical conditions. In addition to the amounts of eluted monomers, mathematical modeling of elution kinetics reveals composite restorations as potential chronic sources of leachable monomers. The aim of this work was ...
Afara I - - 2012
The determination of the characteristics of articular cartilage such as thickness, stiffness and swelling, especially in the form that can facilitate real-time decisions and diagnostics is still a matter for research and development. This paper correlates near infrared spectroscopy with mechanically measured cartilage thickness to establish a fast, non-destructive, repeatable ...
Afara Isaac - - 2012
OBJECTIVE: The aim of this study was to demonstrate the potential of near-infrared (NIR) spectroscopy for categorizing cartilage degeneration induced in animal models. METHOD: Three models of osteoarthritic degeneration were induced in laboratory rats via one of the following methods: (i) menisectomy (MSX); (ii) anterior cruciate ligament transaction (ACLT); and ...
Räsänen Lasse P - - 2012
A subject-specific collagen architecture of cartilage, obtained from T(2) mapping of 3.0 T magnetic resonance imaging (MRI; data from the Osteoarthritis Initiative), was implemented into a 2D finite element model of a knee joint with fibril-reinforced poroviscoelastic cartilage properties. For comparison, we created two models with alternative collagen architectures, addressing the ...
Argente Dos Santos H A F - - 2012
Cardiovascular disease has become a major global health care problem in the present decade. To tackle this problem, the use of cardiovascular stents has been considered a promising and effective approach. Numerical simulations to evaluate the in vivo behavior of stents are becoming more and more important to assess potential ...
Hutson Joel D - - 2012
Recent studies have presented range of motion (ROM) data in degrees for dinosaur forelimb joints, usually via physical manipulation of one individual. Using these data, researchers have inferred limb orientations, postures, gaits, ecological functions and even phylogenetic trends within clades. However, important areas of concern remain unaddressed; for example, how ...
Murphy Colm - - 2012
The leatherback turtle regularly undertakes deep dives and has been recorded attaining depths in excess of 1,200 m. Its trachea is an almost solid, elliptical-section tube of uncalcified hyaline cartilage with minimal connective tissue between successive rings. The structure appears to be advantageous for diving and perfectly designed for withstanding ...
Halloran J P - - 2012
Articular cartilage experiences significant mechanical loads during daily activities. Healthy cartilage provides the capacity for load bearing and regulates the mechanobiological processes for tissue development, maintenance, and repair. Experimental studies at multiple scales have provided a fundamental understanding of macroscopic mechanical function, evaluation of the micromechanical environment of chondrocytes, and ...
Moody Hayley R HR Science and Engineering Faculty, Queensland University of Technology, Brisbane, Queensland, - - 2012
A total histological grade does not necessarily distinguish between different manifestations of cartilage damage or degeneration. An accurate and reliable histological assessment method is required to separate normal and pathological tissue within a joint during treatment of degenerative joint conditions and to sub-classify the latter in meaningful ways. The Modified ...
Seifzadeh A - - 2012
BACKGROUND: Conventional models to evaluate degenerated cartilage do not consider nonlinear permeability and proteoglycan viscous effects. Some models also utilize spring elements to represent the viscous effects of the fibers, thus application tothe modeling of nonuniform deformations such as those that occur in indentation tests. The purpose of this study ...
Mabvuure Nigel - - 2012
Conditions affecting cartilage through damage or age-related degeneration pose significant challenges to individual patients and their healthcare systems. The disease burden will rise in the future as life expectancy increases. This has resulted in vigorous efforts to develop novel therapies to meet current and future needs. Due to the limited ...
Forman Jason L - - 2012
The costal cartilage often undergoes progressive calcification with age. This study sought to investigate the effects of calcification on the structural mechanics of whole costal cartilage segments. Models were developed for five costal cartilage specimens, including representations of the cartilage, the perichondrium, calcification, and segments of the rib and sternum. ...
Rousseau J Ch - - 2012
Osteoarthritis (OA) is considered as a chronic disease with a long "silent" period. The diagnosis is generally based on clinical symptoms and radiographic changes. However X-ray has a poor sensitivity and a relatively large precision error that does not allow an early detection of OA or the monitoring of joint ...
Abd Latif Mohd Juzaila - - 2012
The spinal facet joints are known to be an important component in the kinematics and the load transmission of the spine. The articular cartilage in the facet joint is prone to degenerative changes which lead to back pain and treatments for the condition have had limited long term success. There ...
1 2 3 4 5 6 7 8 9 10 >