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https://www.readbyqxmd.com/read/28110403/delayed-asymptomatic-coil-migrations-toward-different-arteries-after-aneurysmal-embolization-case-report
#1
Tomoya Kamide, Kouichi Misaki, Iku Nambu, Masanao Mohri, Naoyuki Uchiyama, Mitsutoshi Nakada
Delayed coil migration after endovascular treatment with detachable coils, particularly several months after treatment, is extremely rare. In this report, the authors describe a 77-year-old female in whom delayed coil migration to the anterior cerebral artery and posterior communicating artery (PCoA) developed 3 months after an uncomplicated aneurysm embolization. The patient was successfully retreated with a closed-cell stent. Computational fluid dynamics (CFD) revealed high wall shear stress (WSS) and multiple vortices in the residual cavity of the initially treated aneurysm...
January 21, 2017: Acta Neurochirurgica
https://www.readbyqxmd.com/read/28108202/evaluation-of-coronary-flow-conditions-in-complex-coronary-artery-bifurcations-stenting-using-computational-fluid-dynamics-impact-of-final-proximal-optimization-technique-on-different-double-stent-techniques
#2
Gianluca Rigatelli, Marco Zuin, Fabio Dell'Avvocata, Dobrin Vassilev, Ramesh Daggubati, Thach Nguyen, Nguyen Van Viet Thang, Nicolas Foin
BACKGROUND/PURPOSE: Computational fluid dynamics (CFD) have been recently adopted in many fields of cardiovascular medicine and in interventional cardiology. Using CFD analysis we compared the use of different PCI procedures, with and without the utilization of a proximal optimization technique (POT), on a complex coronary artery bifurcation. METHODS/MATERIALS: For the analysis, we considered a hypothetic model of a left anterior descending artery-diagonal Medina 1,1,1 bifurcation type with a diameter of the proximal main branch (MB) and the side branch (SB) set at 3...
January 9, 2017: Cardiovascular Revascularization Medicine: Including Molecular Interventions
https://www.readbyqxmd.com/read/28094902/characteristics-of-dust-particles-abraded-from-pesticide-treated-seeds-2-density-porosity-and-chemical-content
#3
Dieter Foque, Wouter Devarrewaere, Pieter Verboven, David Nuyttens
BACKGROUND: Apart from particle size, drift of abraded seed particles during sowing is mainly affected by two other physical properties viz. particle shape and envelope density. The impact of these abraded seed particles on the environment is highly dependable on their active ingredient content. In this study, the envelope density and chemical content of dust abraded from seeds was determined as a function of particle size for six seed species. RESULTS: Envelope density and active ingredient content both change as a of function of particle size...
January 17, 2017: Pest Management Science
https://www.readbyqxmd.com/read/28092136/computational-fluid-dynamic-modeling-of-nose-to-ceiling-head-positioning-for-sphenoid-sinus-irrigation
#4
John R Craig, James N Palmer, Kai Zhao
BACKGROUND: After sinus surgery, patients are commonly instructed to irrigate with saline irrigations with their heads over a sink and noses directed inferiorly (nose-to-floor). Although irrigations can penetrate the sinuses in this head position, no study has assessed whether sphenoid sinus penetration can be improved by irrigating with the nose directed superiorly (nose-to-ceiling). The purpose of this study was to use a validated computational fluid dynamics (CFD) model of sinus irrigations to assess the difference in sphenoid sinus delivery of irrigations after irrigating in a nose-to-floor vs nose-to-ceiling head position...
January 16, 2017: International Forum of Allergy & Rhinology
https://www.readbyqxmd.com/read/28089607/estimates-of-nasal-airflow-at-the-nasal-cycle-mid-point-improve-the-correlation-between-objective-and-subjective-measures-of-nasal-patency
#5
Courtney Gaberino, John S Rhee, Guilherme J M Garcia
INTRODUCTION: The nasal cycle represents a significant challenge when comparing pre- and post-surgery objective measures of nasal airflow. METHODS: Computational fluid dynamics (CFD) simulations of nasal airflow were conducted in 12 nasal airway obstruction patients showing significant nasal cycling between pre- and post-surgery computed tomography scans. To correct for the nasal cycle, mid-cycle models were created virtually. Subjective scores of nasal patency were obtained via the Nasal Obstruction Symptom Evaluation (NOSE) and unilateral visual analog scale (VAS)...
January 9, 2017: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/28088305/inertial-particle-dynamics-in-large-artery-flows-implications-for-modeling-arterial-embolisms
#6
Debanjan Mukherjee, Shawn C Shadden
The complexity of inertial particle dynamics through swirling chaotic flow structures characteristic of pulsatile large-artery hemodynamics renders significant challenges in predictive understanding of transport of such particles. This is specifically crucial for arterial embolisms, where knowledge of embolus transport to major vascular beds helps in disease diagnosis and surgical planning. Using a computational framework built upon image-based CFD and discrete particle dynamics modeling, a multi-parameter sampling-based study was conducted on embolic particle dynamics and transport...
December 29, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/28080305/critical-review-of-the-building-downwash-algorithms-in-aermod
#7
Ron L Petersen, Sergio Guerra, Anthony Bova
This paper documents theoretical and other problems in PRIME along with CFD simulations and wind tunnel observations that support these findings. While AERMOD/PRIME may provide accurate and unbiased estimates (within a factor of two) for some building configurations, a major review and update is needed so that accurate estimates can be obtained for other building configurations where significant overpredictions or underpredictions are common due to downwash effects. This will ensure that regulatory evaluations subject to dispersion modeling requirements can be based on an accurate model...
January 12, 2017: Journal of the Air & Waste Management Association
https://www.readbyqxmd.com/read/28075194/aerosol-drug-delivery-during-noninvasive-positive-pressure-ventilation-effects-of-intersubject-variability-and-excipient-enhanced-growth
#8
Ross L Walenga, P Worth Longest, Anubhav Kaviratna, Michael Hindle
BACKGROUND: Nebulized aerosol drug delivery during the administration of noninvasive positive pressure ventilation (NPPV) is commonly implemented. While studies have shown improved patient outcomes for this therapeutic approach, aerosol delivery efficiency is reported to be low with high variability in lung-deposited dose. Excipient enhanced growth (EEG) aerosol delivery is a newly proposed technique that may improve drug delivery efficiency and reduce intersubject aerosol delivery variability when coupled with NPPV...
January 11, 2017: Journal of Aerosol Medicine and Pulmonary Drug Delivery
https://www.readbyqxmd.com/read/28062122/airflow-behavior-changes-in-upper-airway-caused-by-different-head-and-neck-positions-comparison-by-computational-fluid-dynamics
#9
Wei Wei, Shi-Wei Huang, Lian-Hua Chen, Yang Qi, Yi-Min Qiu, Shi-Tong Li
The feasibility of computational fluid dynamics (CFD) to evaluate airflow characteristics in different head and neck positions has not been established. This study compared the changes in volume and airflow behavior of the upper airway by CFD simulation to predict the influence of anatomical and physiological airway changes due to different head-neck positions on mechanical ventilation. One awake volunteer with no risk of difficult airway underwent computed tomography in neutral position, extension position (both head and neck extended), and sniffing position (head extended and neck flexed)...
December 29, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/28057349/flow-patterns-in-the-jugular-veins-of-pulsatile-tinnitus-patients
#10
Evan Kao, Sarah Kefayati, Matthew R Amans, Farshid Faraji, Megan Ballweber, Van Halbach, David Saloner
Pulsatile Tinnitus (PT) is a pulse-synchronous sound heard in the absence of an external source. PT is often related to abnormal flow in vascular structures near the cochlea. One vascular territory implicated in PT is the internal jugular vein (IJV). Using computational fluid dynamics (CFD) based on patient-specific Magnetic Resonance Imaging (MRI), we investigated the flow within the IJV of seven subjects, four symptomatic and three asymptomatic of PT. We found that there were two extreme anatomic types classified by the shape and position of the jugular bulbs: elevated and rounded...
December 14, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/28051019/hemodynamics-in-transplant-renal-artery-stenosis-and-its-alteration-after-stent-implantation-based-on-a-patient-specific-computational-fluid-dynamics-model
#11
Hong-Yang Wang, Long-Shan Liu, Hai-Ming Cao, Jun Li, Rong-Hai Deng, Qian Fu, Huan-Xi Zhang, Ji-Guang Fei, Chang-Xi Wang
BACKGROUND: Accumulating studies on computational fluid dynamics (CFD) support the involvement of hemodynamic factors in artery stenosis. Based on a patient-specific CFD model, the present study aimed to investigate the hemodynamic characteristics of transplant renal artery stenosis (TRAS) and its alteration after stent treatment. METHODS: Computed tomography angiography (CTA) data of kidney transplant recipients in a single transplant center from April 2013 to November 2014 were reviewed...
2017: Chinese Medical Journal
https://www.readbyqxmd.com/read/28047187/tu-h-campus-iep2-03-development-of-3d-printed-coronary-phantoms-for-in-vitro-ct-ffr-validation-using-data-from-320-detector-row-coronary-ct-angiography
#12
C Ionita, E Angel, D Mitsouras, S Rudin, D Bednarek, S Zaid, M Wilson, F Rybicki
PURPOSE: To validate Computed Tomography Fractional Flow Reserve (CT-FFR) measurements with accurate 3D printed coronary phantoms. METHODS: DICOM data from four phases in two patients imaged with a standard 320 × 0.5mm coronary CT acquisition (70-80% cardiac cycle) underwent semi-automated segmentation using a research workstation. Both patients had a >50% stenosis from the clinical image interpretation. Each volume was saved as a Stereo Lithographic (STL) file with 250 micron resolution...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28035168/computational-models-for-nanoscale-fluid-dynamics-and-transport-inspired-by-nonequilibrium-thermodynamics
#13
Ravi Radhakrishnan, Hsiu-Yu Yu, David M Eckmann, Portonovo S Ayyaswamy
Traditionally, the numerical computation of particle motion in a fluid is resolved through computational fluid dynamics (CFD). However, resolving the motion of nanoparticles poses additional challenges due to the coupling between the Brownian and hydrodynamic forces. Here, we focus on the Brownian motion of a nanoparticle coupled to adhesive interactions and confining-wall-mediated hydrodynamic interactions. We discuss several techniques that are founded on the basis of combining CFD methods with the theory of nonequilibrium statistical mechanics in order to simultaneously conserve thermal equipartition and to show correct hydrodynamic correlations...
March 2017: Journal of Heat Transfer
https://www.readbyqxmd.com/read/28028981/assessment-of-selected-rotem-parameters-kinetics-of-fibrinogen-polymerization-and-plasmin-amidolytic-activity-in-patients-with-congenital-fibrinogen-defects
#14
Jacek Treliński, Katarzyna Pachniewska, Justyna Matczak, Marta Robak, Krzysztof Chojnowski
BACKGROUND: Congenital fibrinogen disorders (CFD) are rare fibrinogen deficiencies which may be quantitative or functional. The clinical course of hypofibrinogenemia (hypoFI) or dysfibrinogenemia (dysFI) is unpredictable and cannot be determined by the application of standard hemostasis tests. OBJECTIVES: The main aim of this study was to assess ROTEM parameters in CFD patients. MATERIAL AND METHODS: Nine patients with CFD were studied. The fibrinogen concentration was measured functionally and antigenically...
November 2016: Advances in Clinical and Experimental Medicine: Official Organ Wroclaw Medical University
https://www.readbyqxmd.com/read/28013126/optimization-of-mbr-hydrodynamics-for-cake-layer-fouling-control-through-cfd-simulation-and-rsm-design
#15
Min Yang, Dawei Yu, Mengmeng Liu, Libing Zheng, Xiang Zheng, Yuansong Wei, Fang Wang, Yaobo Fan
Membrane fouling is an important issue for membrane bioreactor (MBR) operation. This paper aims at the investigation and the controlling of reversible membrane fouling due to cake layer formation and foulants deposition by optimizing MBR hydrodynamics through the combination of computational fluid dynamics (CFD) and design of experiment (DOE). The model was validated by comparing simulations with measurements of liquid velocity and dissolved oxygen (DO) concentration in a lab-scale submerged MBR. The results demonstrated that the sludge concentration is the most influencing for responses including shear stress, particle deposition propensity (PDP), sludge viscosity and strain rate...
March 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28011839/patient-specific-modeling-of-left-ventricular-electromechanics-as-a-driver-for-haemodynamic-analysis
#16
Christoph M Augustin, Andrew Crozier, Aurel Neic, Anton J Prassl, Elias Karabelas, Tiago Ferreira da Silva, Joao F Fernandes, Fernando Campos, Titus Kuehne, Gernot Plank
AIMS: Models of blood flow in the left ventricle (LV) and aorta are an important tool for analysing the interplay between LV deformation and flow patterns. Typically, image-based kinematic models describing endocardial motion are used as an input to blood flow simulations. While such models are suitable for analysing the hemodynamic status quo, they are limited in predicting the response to interventions that alter afterload conditions. Mechano-fluidic models using biophysically detailed electromechanical (EM) models have the potential to overcome this limitation, but are more costly to build and compute...
December 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28009713/outcomes-and-trends-of-ventricular-assist-device-selection-in-children-with-end-stage-heart-failure
#17
Jacob R Miller, Timothy S Lancaster, Deirdre J Epstein, Nicholas C DuPont, Kathleen E Simpson, Chesney Castleberry, Charles E Canter, Pirooz Eghtesady, Umar S Boston
We aimed to examine trends in VAD selection, continuous-flow devices (CFD) versus pulsatile (PFD), and their associated outcomes in children eligible for both device types. To accomplish this, the United Network for Organ Sharing database was reviewed for pediatric patients listed for heart transplant (HT) from January of 2007 through June of 2014. Patients were included if a durable VAD was present at wait listing or when removed from the waiting list, and who met size eligibility for a CFD (BSA > 1.0 m2)...
December 20, 2016: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
https://www.readbyqxmd.com/read/27996695/reduced-combustion-mechanism-for-c1-c4-hydrocarbons-and-its-application-in-cfd-flare-modeling
#18
Vijaya Damodara, Daniel H Chen, Helen H Lou, Kader M A Rasel, Peyton Richmond, Anan Wang, Xianchang Li
Emissions from flares constitute unburned hydrocarbons, CO, soot, and other partially burned and altered hydrocarbons along with CO2 and water. Soot or visible smoke is of particular concern for flare operators /regulatory agencies. The goal of the study is to develop a computational fluid dynamics (CFD) model capable of predicting flare combustion efficiency (CE) and soot emission. Since detailed combustion mechanisms are too complicated for (CFD) application, a 50-species reduced mechanism, LU 3.0.1, was developed...
December 20, 2016: Journal of the Air & Waste Management Association
https://www.readbyqxmd.com/read/27993478/pharmaceutical-aerosols-deposition-patterns-from-a-dry-powder-inhaler-euler-lagrangian-prediction-and-validation
#19
Ravishekar Ravi Kannan, A J Przekwas, Narender Singh, Renishkumar Delvadia, Geng Tian, Ross Walenga
This study uses Computational Fluid Dynamics (CFD) to predict, analyze and validate the deposition patterns in a human lung for a Budesonide drug delivered from the Novolizer Dry Powder Inhaler device. We used a test case of known deposition patterns to validate our computational Euler Lagrangian-based deposition predictions. Two different lung models are used: (i) a basic ring-less trachea model and (ii) an advanced Human Zygote5 model. Unlike earlier attempts, the current simulations do not include the device in the computational domain...
December 16, 2016: Medical Engineering & Physics
https://www.readbyqxmd.com/read/27987805/spray-freeze-dried-nanofibrillated-cellulose-aerogels-with-thermal-superinsulating-properties
#20
Clara Jiménez-Saelices, Bastien Seantier, Bernard Cathala, Yves Grohens
Nanofibrillated cellulose (NFC) aerogels were prepared by spray freeze-drying (SFD). Their structural, mechanical and thermal insulation properties were compared to those of NFC aerogels prepared by conventional freeze-drying (CFD). The purpose of this investigation is to develop superinsulating bioaerogels by reducing their pore size. Severe reduction of the aerogel pore size and skeleton architecture were observed by SEM, aerogels prepared by SFD method show a fibril skeleton morphology, which defines a mesoporous structure...
February 10, 2017: Carbohydrate Polymers
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