WorldWideScience

Sample records for artery comparing finite

  1. Tactile Distinction of an Artery and a Tumor in a Soft Tissue by Finite Element Method

    Directory of Open Access Journals (Sweden)

    Ali A.  Mehrizi

    2008-01-01

    Full Text Available Tactile detection of a tumor and an artery in a tissue and distinction of a healthy artery from a stenotic artery, using finite element method, are presented. Four 2D models of tissue have been created: tissue itself, tissue including a tumor (TIT, tissue including a healthy artery (TIHA, and tissue including a stenotic artery (TISA. After solving four models with similar boundary conditions and loadings, the 2D tactile mappings and stress graphs for upper nodes of models, which have key importance for transferring tactile data, were explored. Then, by comparing these results, if the stress values of nodes were constant and equal, tissue is unlikely to have any tumor or artery embedded. Otherwise, if the stress graph included a peak, the tissue had a tumor or an artery. Additionally, it was observed that the stress graph of tissue including an artery is time-dependent in comparison with the tissue including a tumor. Further, it was concluded that a stenotic artery had larger stress peak than a healthy artery.

  2. Arterial elasticity imaging: comparison of finite-element analysis models with high-resolution ultrasound speckle tracking

    Directory of Open Access Journals (Sweden)

    Park Dae

    2010-06-01

    Full Text Available Abstract Background The nonlinear mechanical properties of internal organs and tissues may be measured with unparalleled precision using ultrasound imaging with phase-sensitive speckle tracking. The many potential applications of this important noninvasive diagnostic approach include measurement of arterial stiffness, which is associated with numerous major disease processes. The accuracy of previous ultrasound measurements of arterial stiffness and vascular elasticity has been limited by the relatively low strain of nonlinear structures under normal physiologic pressure and the measurement assumption that the effect of the surrounding tissue modulus might be ignored in both physiologic and pressure equalized conditions. Methods This study performed high-resolution ultrasound imaging of the brachial artery in a healthy adult subject under normal physiologic pressure and the use of external pressure (pressure equalization to increase strain. These ultrasound results were compared to measurements of arterial strain as determined by finite-element analysis models with and without a surrounding tissue, which was represented by homogenous material with fixed elastic modulus. Results Use of the pressure equalization technique during imaging resulted in average strain values of 26% and 18% at the top and sides, respectively, compared to 5% and 2%, at the top and sides, respectively, under physiologic pressure. In the artery model that included surrounding tissue, strain was 19% and 16% under pressure equalization versus 9% and 13% at the top and sides, respectively, under physiologic pressure. The model without surrounding tissue had slightly higher levels of strain under physiologic pressure compared to the other model, but the resulting strain values under pressure equalization were > 60% and did not correspond to experimental values. Conclusions Since pressure equalization may increase the dynamic range of strain imaging, the effect of the

  3. Thermal buckling comparative analysis using Different FE (Finite Element) tools

    Energy Technology Data Exchange (ETDEWEB)

    Banasiak, Waldemar; Labouriau, Pedro [INTECSEA do Brasil, Rio de Janeiro, RJ (Brazil); Burnett, Christopher [INTECSEA UK, Surrey (United Kingdom); Falepin, Hendrik [Fugro Engineers SA/NV, Brussels (Belgium)

    2009-12-19

    High operational temperature and pressure in offshore pipelines may lead to unexpected lateral movements, sometimes call lateral buckling, which can have serious consequences for the integrity of the pipeline. The phenomenon of lateral buckling in offshore pipelines needs to be analysed in the design phase using FEM. The analysis should take into account many parameters, including operational temperature and pressure, fluid characteristic, seabed profile, soil parameters, coatings of the pipe, free spans etc. The buckling initiation force is sensitive to small changes of any initial geometric out-of-straightness, thus the modeling of the as-laid state of the pipeline is an important part of the design process. Recently some dedicated finite elements programs have been created making modeling of the offshore environment more convenient that has been the case with the use of general purpose finite element software. The present paper aims to compare thermal buckling analysis of sub sea pipeline performed using different finite elements tools, i.e. general purpose programs (ANSYS, ABAQUS) and dedicated software (SAGE Profile 3D) for a single pipeline resting on an the seabed. The analyses considered the pipeline resting on a flat seabed with a small levels of out-of straightness initiating the lateral buckling. The results show the quite good agreement of results of buckling in elastic range and in the conclusions next comparative analyses with sensitivity cases are recommended. (author)

  4. Comparable three months' outcome of total arterial revascularization versus conventional coronary surgery: Copenhagen Arterial Revascularization Randomized Patency and Outcome trial

    DEFF Research Database (Denmark)

    Damgaard, S.; Lund, J.T.; Lilleor, N.B.; Perko, M.J.; Sander, K.; Dimo, B.; Jensen, Maiken Brit; Madsen, Jan Kyst; Kelbaek, H.; Steinbruchel, D.A.

    2008-01-01

    single-center trial, 331 patients underwent total arterial revascularization using single or bilateral internal thoracic and radial arteries versus conventional revascularization using the left internal thoracic artery and saphenous vein grafts. We report the results from 3 months' follow-up. RESULTS......OBJECTIVE: The in-hospital safety of total arterial revascularization for coronary artery bypass surgery seems to be comparable to conventional revascularization, but randomized trials evaluating this are few and data on complications in the postoperative months are sparse. METHODS: In a randomized......: The mean age of patients was 59 +/- 8 years, and 39 were women (12%). The median EuroSCORE was 2 (interquartile range 1-4). The arterial group comprised 161 patients, and the conventional group comprised 170 patients. The mean number of bypasses in the arterial group was 2.9 +/- 0.9 versus 3.2 +/- 0...

  5. Comparative anatomical studies on the thyroid and thymic arteries. VI. Diprotodont marsupials.

    Science.gov (United States)

    Yamasaki, Masahiro

    2016-06-01

    The thyroid and thymic arteries in 44 specimens from 18 species belonging to the diprotodont marsupials were investigated. The results were compared with those of polyprotodont marsupials, suncuses, rats, rabbits, guinea pigs, and man. The superior thyroid artery was constant in three superfamily groups. The inferior thyroid artery was extremely rare. The superior thymic artery arising from the thyrocervical trunk was observed in 1 phalangeroid and 2 macropodoids, and that arising from the vertebral artery occurred in 1 macropodoid. The middle thymic artery occurred in 1 phalangeroid, but was abundant in macropodoids. The inferior thymic artery was constant in koalas and phalangeroids, but was absent in half of the macropodoids. The thyroid ima, middle thymothyroid, and the supreme thymic arteries were absent in all diprotodonts. In addition to the usual thymus, diprotodonts have the superficial cervical thymus, which is only shared with guinea pigs. The superior superficial cervical thymic artery was absent in koalas and in half of the macropodoids, but was abundant in the phalangeroids. Conversely, the inferior superficial cervical thymic artery was constant in koalas and was dominant in the macropodoids. These results show that variations in the arterial patterns for both organs were much more prevalent in macropodoids than in phalangeroids, while the arterial patterns in koalas were characteristic. As a whole, the arteries for both organs were more complex in diprotodonts than in polyprotodonts or rats, but more simple than those in rabbits or man. The superior superficial cervical thymic arteries, which showed various patterns, were compared with those in guinea pigs. PMID:26472114

  6. Comparative analysis of finite field-dependent BRST transformations

    CERN Document Server

    Moshin, Pavel Yu

    2016-01-01

    We present a review of our recent study (A. Reshetnyak, IJMPA 29 (2014) 1450128; P. Moshin, A. Reshetnyak, Nucl. Phys. B 888 (2014) 92; Phys. Lett B 739 (2014) 110; IJMPA 29 (2014) 1450159; IJMPA 30 (2015) 1550021; [arxiv:1506.04660 [hep-th]), in which the concept of finite field-dependent BRST and BRST-antiBRST transformations for gauge theories was introduced, and their properties investigated. An algorithm of exact calculation for the Jacobian of a respective change of variables in the path integral is presented. Applications to the Yang--Mills theory and Standard Model, in view of infra-red (Gribov) peculiarities, are discussed.

  7. Comparative anatomical studies on the thyroid and thymic arteries. II. Polyprotodont marsupials.

    OpenAIRE

    Yamasaki, M

    1993-01-01

    The thyroid and thymic arteries were investigated in 27 specimens from 9 species belonging to the Australian Polyprotodont marsupials, which are subdivided into 2 superfamilies, Dasyuroidea and Perameloidea. The results were compared with those in rats and humans. The site of origin of the superior thyroid artery ranged from the external carotid artery to the common carotid in Dasyuroids, and converged on the external carotid and the bifurcation of the common carotid in Perameloids. The cours...

  8. Finite element analyses for design evaluation of biodegradable magnesium alloy stents in arterial vessels

    International Nuclear Information System (INIS)

    Biodegradable magnesium alloy stents (MAS) can provide a great benefit for diseased vessels and avoid the long-term incompatible interactions between vessels and permanent stent platforms. However, the existing MAS showed insufficient scaffolding to the target vessels due to short degradation time. In this study, a three dimensional finite element model combined with a degradable material model of AZ31 (Al 0.03, Zn 0.01, Mn 0.002 and Mg balance, mass percentage) was applied to three different MAS designs including an already implanted stent (Stent A), an optimized design (Stent B) and a patented stent design (Stent C). One ring of each design was implanted through a simulation in a vessel model then degraded with the changing interaction between outer stent surface and the vessel. Results showed that a proper stent design (Stent B) can lead to an increase of nearly 120% in half normalized recoil time of the vessel compared to the Stent A; moreover, the expectation that the MAS design, with more mass and optimized mechanical properties, can increase scaffolding time was verified numerically. The Stent C has more materials than Stent B; however, it only increased the half normalized recoil time of the vessel by nearly 50% compared to the Stent A because of much higher stress concentration than that of Stent B. The 3D model can provide a convenient design and testing tool for novel magnesium alloy stents.

  9. Finite element analyses for design evaluation of biodegradable magnesium alloy stents in arterial vessels

    Energy Technology Data Exchange (ETDEWEB)

    Wu Wei [Laboratory of Biological Structure Mechanics, Structural Engineering Department, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan (Italy); Gastaldi, Dario, E-mail: dario.gastaldi@polimi.it [Laboratory of Biological Structure Mechanics, Structural Engineering Department, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan (Italy); Yang Ke; Tan Lili [Division of Specialized Materials and Devices, Institute of Metal Research, Chinese Academy of Sciences, Shenyang (China); Petrini, Lorenza; Migliavacca, Francesco [Laboratory of Biological Structure Mechanics, Structural Engineering Department, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan (Italy)

    2011-12-15

    Biodegradable magnesium alloy stents (MAS) can provide a great benefit for diseased vessels and avoid the long-term incompatible interactions between vessels and permanent stent platforms. However, the existing MAS showed insufficient scaffolding to the target vessels due to short degradation time. In this study, a three dimensional finite element model combined with a degradable material model of AZ31 (Al 0.03, Zn 0.01, Mn 0.002 and Mg balance, mass percentage) was applied to three different MAS designs including an already implanted stent (Stent A), an optimized design (Stent B) and a patented stent design (Stent C). One ring of each design was implanted through a simulation in a vessel model then degraded with the changing interaction between outer stent surface and the vessel. Results showed that a proper stent design (Stent B) can lead to an increase of nearly 120% in half normalized recoil time of the vessel compared to the Stent A; moreover, the expectation that the MAS design, with more mass and optimized mechanical properties, can increase scaffolding time was verified numerically. The Stent C has more materials than Stent B; however, it only increased the half normalized recoil time of the vessel by nearly 50% compared to the Stent A because of much higher stress concentration than that of Stent B. The 3D model can provide a convenient design and testing tool for novel magnesium alloy stents.

  10. Mechanical Interaction of an Expanding Coiled Stent with a Plaque-Containing Arterial Wall: A Finite Element Analysis.

    Science.gov (United States)

    Welch, Tré R; Eberhart, Robert C; Banerjee, Subhash; Chuong, Cheng-Jen

    2016-03-01

    Wall injury is observed during stent expansion within atherosclerotic arteries, related in part to stimulation of the inflammatory process. Wall stress and strain induced by stent expansion can be closely examined by finite element analysis (FEA), thus shedding light on procedure-induced sources of inflammation. The purpose of this work was to use FEA to examine the interaction of a coiled polymer stent with a plaque-containing arterial wall during stent expansion. An asymmetric fibrotic plaque-containing arterial wall model was created from intravascular ultrasound (IVUS) images of a diseased artery. A 3D model for a coil stent at unexpanded state was generated in SolidWorks. They were imported into ANSYS for FEA of combined stent expansion and fibrotic plaque-distortion. We simulated the stent expansion in the plaqued lumen by increasing balloon pressure from 0 to 12 atm in 1 atm step. At increasing pressure, we examined how the expanding stent exerts forces on the fibrotic plaque and vascular wall components, and how the latter collectively resist and balance the expansive forces from the stent. Results show the expanding coiled stent creates high stresses within the plaque and the surrounding fibrotic capsule. Lower stresses were observed in adjacent medial and adventitial layers. High principal strains were observed in plaque and fibrotic capsule. The results suggest fibrotic capsule rupture might occur at localized regions. The FEA/IVUS method can be adapted for routine examination of the effects of the expansion of selected furled stents against IVUS-reconstructed diseased vessels, to improve stent deployment practices. PMID:26621671

  11. Modeling blood flow circulation in intracranial arterial networks: a comparative 3D/1D simulation study.

    Science.gov (United States)

    Grinberg, L; Cheever, E; Anor, T; Madsen, J R; Karniadakis, G E

    2011-01-01

    We compare results from numerical simulations of pulsatile blood flow in two patient-specific intracranial arterial networks using one-dimensional (1D) and three-dimensional (3D) models. Specifically, we focus on the pressure and flowrate distribution at different segments of the network computed by the two models. Results obtained with 1D and 3D models with rigid walls show good agreement in massflow distribution at tens of arterial junctions and also in pressure drop along the arteries. The 3D simulations with the rigid walls predict higher amplitude of the flowrate and pressure temporal oscillations than the 1D simulations with compliant walls at various segments even for small time-variations in the arterial cross-sectional areas. Sensitivity of the flow and pressure with respect to variation in the elasticity parameters is investigated with the 1D model. PMID:20661645

  12. Comparing Color Doppler Ultrasonography and Angiography to Assess Traumatic Arterial Injuries of the Extremities

    International Nuclear Information System (INIS)

    Traumatic events are one of the major causes of arterial injuries. Physical examination is not a good predictor of the extent of injuries and arteriography is considered as the gold standard for this purpose. In the recent years, noninvasive modalities are increasingly replacing diagnostic arteriography. Color Doppler ultrasonography (USG) is an excellent method to investigate arterial diseases. The present study aimed to evaluate the diagnostic value of color Doppler USG compared to conventional angiography in traumatic arterial injuries of extremities. Seventy-five patients with extremity trauma suspicious for arterial injury were examined by color Doppler USG just before angiography. Doppler pattern and flow states were assessed, then angiography was performed. The results of duplex USG were compared with angiography. Color Doppler USG had a sensitivity of 95% and specificity of 98% in diagnosis of arterial injury. Positive and negative predictive values of Doppler USG were 92.5% and 94.2%, respectively. Color Doppler USG can be used as a reliable modality with acceptable sensitivity and specificity values to screen hemodynamically stable patients with limb trauma suspicious for arterial injury

  13. An Efficient Finite Element Framework to Assess Flexibility Performances of SMA Self-Expandable Carotid Artery Stents

    Science.gov (United States)

    Ferraro, Mauro; Auricchio, Ferdinando; Boatti, Elisa; Scalet, Giulia; Conti, Michele; Morganti, Simone; Reali, Alessandro

    2015-01-01

    Computer-based simulations are nowadays widely exploited for the prediction of the mechanical behavior of different biomedical devices. In this aspect, structural finite element analyses (FEA) are currently the preferred computational tool to evaluate the stent response under bending. This work aims at developing a computational framework based on linear and higher order FEA to evaluate the flexibility of self-expandable carotid artery stents. In particular, numerical simulations involving large deformations and inelastic shape memory alloy constitutive modeling are performed, and the results suggest that the employment of higher order FEA allows accurately representing the computational domain and getting a better approximation of the solution with a widely-reduced number of degrees of freedom with respect to linear FEA. Moreover, when buckling phenomena occur, higher order FEA presents a superior capability of reproducing the nonlinear local effects related to buckling phenomena. PMID:26184329

  14. Comparably improved health-related quality of life after total arterial revascularization versus conventional coronary surgery--Copenhagen arterial revascularization randomized patency and outcome trial

    DEFF Research Database (Denmark)

    Damgaard, Sune; Lund, Jens T; Lilleør, Nikolaj B; Perko, Mario J; Madsen, Jan K; Steinbrüchel, Daniel A

    2011-01-01

    OBJECTIVE: We compared health-related quality of life up to 11 months after coronary artery bypass grafting using total arterial revascularization versus conventional coronary surgery. METHODS: In this randomized single-center trial, 161 patients underwent total arterial revascularization using...... single or bilateral internal thoracic artery (ITA) and radial artery grafts versus 170 patients conventionally revascularized using left ITA and saphenous vein grafts. Preoperatively, and at 3 and 11 months, postoperatively, patients filled in the generic questionnaire Short Form-36 (SF-36). RESULTS: The...... general Danish population. On all scales of the SF-36, there was statistically significant improvement at 3 and 11 months in both groups. For 'social functioning', the improvement following total arterial revascularization was significantly higher than following conventional revascularization (P=0...

  15. Automatic Generation of Individual Finite-Element Models for Computational Fluid Dynamics and Computational Structure Mechanics Simulations in the Arteries

    Science.gov (United States)

    Hazer, D.; Schmidt, E.; Unterhinninghofen, R.; Richter, G. M.; Dillmann, R.

    2009-08-01

    Abnormal hemodynamics and biomechanics of blood flow and vessel wall conditions in the arteries may result in severe cardiovascular diseases. Cardiovascular diseases result from complex flow pattern and fatigue of the vessel wall and are prevalent causes leading to high mortality each year. Computational Fluid Dynamics (CFD), Computational Structure Mechanics (CSM) and Fluid Structure Interaction (FSI) have become efficient tools in modeling the individual hemodynamics and biomechanics as well as their interaction in the human arteries. The computations allow non-invasively simulating patient-specific physical parameters of the blood flow and the vessel wall needed for an efficient minimally invasive treatment. The numerical simulations are based on the Finite Element Method (FEM) and require exact and individual mesh models to be provided. In the present study, we developed a numerical tool to automatically generate complex patient-specific Finite Element (FE) mesh models from image-based geometries of healthy and diseased vessels. The mesh generation is optimized based on the integration of mesh control functions for curvature, boundary layers and mesh distribution inside the computational domain. The needed mesh parameters are acquired from a computational grid analysis which ensures mesh-independent and stable simulations. Further, the generated models include appropriate FE sets necessary for the definition of individual boundary conditions, required to solve the system of nonlinear partial differential equations governed by the fluid and solid domains. Based on the results, we have performed computational blood flow and vessel wall simulations in patient-specific aortic models providing a physical insight into the pathological vessel parameters. Automatic mesh generation with individual awareness in terms of geometry and conditions is a prerequisite for performing fast, accurate and realistic FEM-based computations of hemodynamics and biomechanics in the

  16. Transcutaneous monitoring of blood gases: is it comparable with arterialized earlobe sampling?

    Science.gov (United States)

    Dawson, S; Cave, C; Pavord, I; Potter, J F

    1998-03-01

    Researchers are increasingly looking for reliable non-invasive methods of assessing blood gas concentrations, and several new techniques have recently become available. Values derived using arterialized earlobe samples have been found to be comparable with conventional arterial samples, and recent studies have compared transcutaneous blood gas analysis with the traditional arterial samples and found a reasonable level of agreement in particular for the partial pressure of carbon dioxide. There are no data comparing oxygen and carbon dioxide partial pressures (pO2, pCO2) derived from arterialized samples with one of the newer transcutaneous techniques. We therefore simultaneously studied arterialized earlobe blood gas samples and values for pO2 and pCO2 obtained by a transcutaneous monitor (TINA, Radiometer, Copenhagen) in 26 subjects with varying blood gas values. There was a close agreement between the two methods for assessment of pCO2 [mean difference (95% C.I.) between transcutaneous and earlobe values 0.25 kPa (-0.004, 0.5 kPa)], but not for pO2 [1.71 kPa (0.35, 3.07 kPa)]. Similarly, the limits of agreement were narrow for pCO2 compared to those for pO2 (-0.98, 1.47 kPa and -6.44, 3.02 kPa respectively). We conclude that transcutaneous measurement of pCO2 using the TINA is acceptable in the research setting, whereas assessment of pO2 cannot reliably be made using this technique. PMID:9692127

  17. Pituitary dysfunction in survivors of spontaneous subarachnoid hemorrhage of anterior communicating artery and middle cerebral artery aneurysms: A comparative study

    Directory of Open Access Journals (Sweden)

    Pinaki Dutta

    2012-01-01

    Full Text Available Background: The data on incidence of hypopituitarism after SAH are conflicting. Furthermore, it is still not known whether there is any difference in hormonal deficiencies between SAH due to anterior communicating artery (A-com and middle cerebral artery (MCA aneurysms. Materials and Methods: This study includes both retrospective and prospective arms. The data collected included baseline demographic profile, clinical severity on admission to the hospital by the Hunt and Hess grading system and World Federation of Neurological Surgeons (WFNS grading, radiological severity of bleed by the Fisher′s classification, and treatment details. All the patients underwent detailed hormonal evaluation at baseline and 6 months in prospective group while at the end of 1 year in the retrospective group. Hormonal deficiencies between patients with A-com and MCA aneurysmal SAH were compared using appropriate statistical tests. Results: Of 60 patients studied, 47 patients (A-com: 28 and MCA: 19 were in the retrospective group, while 13 patients (A-com-9, MCA-4 were in the prospective group. The baseline data were comparable between the two groups. At or after 6 months follow-up, 19 (31.6% patients, 10 patients with A-com and 9 patients with MCA aneurysmal SAH, had some form of hormone deficiency. Furthermore, there was no difference in endocrine dysfunctions between the two groups. There was no correlation between the severity of hormonal deficiency and the clinical severity of SAH grade by Hunt and Hess and radiological grade of SAH by Fisher′s grade. Conclusion: Hormonal deficiencies are not uncommon in patients with SAH. There is no difference in hormonal deficiencies and severity of hypopituitarism in patients with SAH due to A-com and MCA bleed.

  18. Tympanic, Infrared Skin, and Temporal Artery Scan Thermometers Compared with Rectal Measurement in Children: A Real-Life Assessment

    Directory of Open Access Journals (Sweden)

    Karel Allegaert, MD, PhD

    2014-12-01

    Conclusions: All noninvasive techniques underperformed compared with rectal measurement. The temporal artery scan deviations were smallest, but all noninvasive techniques overestimate lower temperatures and underestimate higher temperatures compared with rectal measurement. In our hands, temporal artery scan measurement seems to be second best, but not yet ideal.

  19. Comparative study of finite element method, isogeometric analysis, and finite volume method in elastic wave propagation of stress discontinuities

    Czech Academy of Sciences Publication Activity Database

    Berezovski, A.; Kolman, Radek; Blažek, Jiří; Kopačka, Ján; Gabriel, Dušan; Plešek, Jiří

    Brno : University of Technology, 2014. ISBN 978-80-214-5018-9. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. Praha (CZ), 06.10.2014-10.10.2014] R&D Projects: GA ČR(CZ) GAP101/11/0288; GA ČR(CZ) GAP101/12/2315 Institutional support: RVO:61388998 Keywords : elastic wave propagation * finite element method * isogeometric analysis * finite volume method * stress discontinuities * spurious oscillations Subject RIV: JR - Other Machinery

  20. COMPARATIVE EVALUATION OF HEMODYNAMIC CHARACTERISTICS IN PATIENTS WITH RHEUMATOID ARTHRITIS AND ARTERIAL HYPERTENSION

    Directory of Open Access Journals (Sweden)

    Y. E. Teregulov

    2015-09-01

    Full Text Available Aim. To study the peculiarities of hemodynamic disorders in patients with rheumatoid arthritis (RA and arterial hypertension (HT, and in patients with hypertension but without RA using the integral indicators of arterial stiffness.Material and methods. The study included 106 RA patients (group 1, among them 83 (78% women and 23 (22% men, mean age 45.3±10.3 years. The group of comparison (group 2 included 63 patients (22 (35% women and 41 (65% men, mean age 47.9±12.8 years with HT stages 1-3. The control group (group 3 consisted of 32 healthy volunteers: 19 women and 13 men, mean age 24.7±5.34 years. All patients underwent ECG and echocardiography. The model of cardiovascular system was used to calculate the modulus of volume elasticity (MVE, mean arterial blood pressure (BP and total peripheral vascular resistance (TPR; stroke volume and cardiac output were measured using echocardiography.Results. Significant differences in the parameters of BP, arterial stiffness and TPR were identified in patients with RA and HT as compared with the patients of the control group. Arterial stiffness in RA patients with HT, as well as without it, was significantly higher and TPR was lower than in hypertensive patients. RA patients with HT were older and had significantly higher values of cardiac output than those without HT. In RA patients hyperkinetic type of hemodynamics was observed in 53.8% of the cases, eukinetic - in 34.9%, hypokinetic - in 11.3%. Hypertensive patients had same types of hemodynamics in 3.2%, 61.9%, and 34.9%, respectively. In healthy people hyperkinetic type was observed in 22.9% of the cases, eukinetic - in 65.6%, hypokinetic - in 12.5%.Conclusions. RA patients as compared with healthy people had significantly higher arterial stiffness indices regardless of BP. At that, hyperkinetic type of hemodynamics prevailed in RA patients, while in hypertensive patients and healthy people - the eukinetic one. Increased stroke volume and cardiac

  1. Partial splenic artery embolization with gelatin sponge or with lipiodol for hypersplenism: a comparative study

    International Nuclear Information System (INIS)

    Objective: To discuss the effects and the complications of partial splenic artery embolization with gelatin sponge or with lipiodol for hypersplenism, to provide scientific information helpful for the selection of embolization materials in clinical practice. Methods: Partial splenic artery embolization with gelatin sponge was performed in forty patients with hypersplenism due to cirrhosis (gelatin sponge group) and partial splenic artery embolization with lipiodol was carried out in another thirty-nine patients (lipiodol group). The clinical data were retrospectively analyzed. The laboratory studies, complications and recurrence were observed and compared between two groups. Results: No significant difference in the reduction of splenic size, in the hemoglobin levels and in the thrombocyte and leucocyte counts existed between two groups (P > 0.05). However, the platelet count in lipiodol group was obviously decreased three months after the treatment. The occurrence of complications in gelatin sponge group was much higher than that in lipiodol group (P < 0.05). The toxic reaction of the liver and gastrointestinal tract in lipiodol group was significantly slighter than that in gelatin sponge group. Conclusion: Partial splenic artery embolization with lipiodol should be employed for the treatment of hypersplenism when the patient is elder and the disease is accompanied by poor liver function, massive ascites, severe dysfunction of blood coagulation and serious portal hypertension. (authors)

  2. [Comparative study of two methods of arterialization of foot veins in ischemic crisis].

    Science.gov (United States)

    Lengua, F; Nuss, J M; Buffet, J M; Lechner, R

    1993-01-01

    Between February 1974 and December 1991, a total of 28 arterializations of the venous network of foot were performed in patients with stage IIIB or IV arteriopathies presenting disseminated femoropopliteal and more distal lesions excluding revascularization by conventional arterial shunt operations. Two groups of patients could be distinguished. The first group, of 8 patients, underwent arterialization by shunt operation with end to end fistula at the distal part of leg and return blood emptying at the dorsal surface of foot (3 cases). The procedure was successful in 50% of cases after a mean follow up of 76 months. The intervention in the second group, of 20 patients, was by end to side fistula of foot after preoperative countercurrent phlebography and the use of a material better adapted for the destruction of the valves. Results were evaluated as successful in 70% of cases at 31 month follow up. After spontaneous closure of the fistula, the collateral circulation provoked by it was sufficient to conserve the acquired benefit. No deaths or cases of cardiac overload were reported as a result of the intervention. Comparative analysis of results showed that the use of the second procedure allowed amputation to be avoided in more than 2/3rds of cases, provided relief from pain, provoked healing of necrosed areas and permitted renewal of walking. The results of this study have demonstrated that venous arterialization of the foot by this method represents an interesting alternative in the saving of a limb destined for amputation. PMID:8496251

  3. Comparative study of finite element method, isogeometric analysis, and finite volume method in elastic wave propagation of stress discontinuities

    Czech Academy of Sciences Publication Activity Database

    Berezovski, A.; Kolman, Radek; Blažek, Jiří; Kopačka, Ján; Gabriel, Dušan; Plešek, Jiří

    2014-01-01

    Roč. 19, č. 12 (2014). ISSN 1435-4934. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. Praha, 06.10.2014-10.10.2014] R&D Projects: GA ČR(CZ) GAP101/11/0288; GA ČR(CZ) GAP101/12/2315 Institutional support : RVO:61388998 Keywords : elastic wave propagation * finite element method * isogeometric analysis * finite volume method * stress discontinuities * spurious oscillations Subject RIV: JR - Other Machinery http://www.ndt.net/events/ECNDT2014/app/ content /Paper/25_Berezovski_Rev1.pdf

  4. TNM Method Results Compared with Finite Element Analysis for a 30 KW SCIM Motor

    Directory of Open Access Journals (Sweden)

    A. Ravi Prasad

    2015-10-01

    Full Text Available The Thermal network model (TNM of ten node 37 thermal resistances is considered as the highly detailed one for thermal distribution of all the TNM models. This model is reported to be the one that can take care of most of the complexities in geometry and estimation of convective heat transfer coefficients. Results obtained for the 30 KW motor using the above TNM model have been compared with that of Finite element Analysis using ANSYS. Listing of the MATLAB programs is presented as annexure.

  5. Protocol for the Arterial Revascularisation Trial (ART. A randomised trial to compare survival following bilateral versus single internal mammary grafting in coronary revascularisation [ISRCTN46552265

    Directory of Open Access Journals (Sweden)

    Flather Marcus

    2006-03-01

    Full Text Available Abstract Background Standard coronary artery bypass graft surgery uses a single internal mammary artery and supplemental vein or radial artery grafts. Several observational studies have suggested a survival benefit with two internal mammary artery grafts compared to a single internal mammary artery graft, but this has not been tested in a randomised trial. The Arterial Revascularisation Trial is a Medical Research Council and British Heart Foundation funded, multi-centre international trial comparing single internal mammary artery grafting versus bilateral internal mammary artery grafting. Methods/Design Twenty centres in the UK, Australia, Poland and Brazil are planning to randomise 3000 coronary artery bypass graft surgery patients to single or bilateral internal mammary artery grafting. Supplemental grafts may be either saphenous vein or radial artery. Coronary artery bypass grafting can be performed as an on-pump or off-pump procedure. The primary outcome is survival at 10 years and secondary end-points include clinical events, quality of life and cost effectiveness. The effect of age, left ventricular function, diabetes, number of grafts, vein grafts and off-pump surgery are pre-specified subgroups. Discussion The Arterial Revascularisation Trial is one of the first randomised trials to evaluate the effects on survival and other clinical outcomes of single internal mammary artery grafting versus bilateral internal mammary artery grafting, and will help to establish the best approach for patients requiring coronary artery bypass graft surgery.

  6. A randomised trial comparing weight loss with aerobic exercise in overweight individuals with coronary artery disease

    DEFF Research Database (Denmark)

    Pedersen, Lene Rørholm Engelbrecht; Olsen, Rasmus H; Jürs, Anders;

    2015-01-01

    BACKGROUND: We aimed to compare the effect of aerobic interval training (AIT) versus a low energy diet (LED) on physical fitness, body composition, cardiovascular risk factors and symptoms in overweight individuals with coronary artery disease (CAD). METHODS AND DESIGN: Seventy non-diabetic parti......BACKGROUND: We aimed to compare the effect of aerobic interval training (AIT) versus a low energy diet (LED) on physical fitness, body composition, cardiovascular risk factors and symptoms in overweight individuals with coronary artery disease (CAD). METHODS AND DESIGN: Seventy non...... per protocol. VO2peak (mL/kg fat free mass(0.67)/min) increased by 10.4% (p = 0.002) following AIT, whereas no change was observed after LED (-3.0%, p = 0.095). The LED group lost 10.6% body weight and 26.6% body fat mass (p < 0.001) compared to 1.6% (p = 0.002) and 5.5% (p < 0.001) following AIT...... their antihypertensive treatment reduced following LED (between-group, p = 0.032). Canadian Cardiovascular Society (CCS), New York Heart Association (NYHA) and anxiety scores were improved, while depressive symptoms remained unchanged. Intention-to-treat analyses including 65 participants (93%) were...

  7. Cost-utility of enoxaparin compared with unfractionated heparin in unstable coronary artery disease

    Directory of Open Access Journals (Sweden)

    Milne Ruairidh

    2001-10-01

    Full Text Available Abstract Background Low molecular weight heparins hold several advantages over unfractionated heparin including convenience of administration. Enoxaparin is one such heparin licensed in the UK for use in unstable coronary artery disease (unstable stable angina and non-Q wave myocardial infarction. In these patients, two large randomised controlled trials and their meta-analysis showed small benefits for enoxaparin over unfractionated heparin at 30–43 days and potentially at one year. We found no relevant published full economic evaluations, only cost studies, one of which was conducted in the UK. The other studies, from the US, Canada and France, are difficult to interpret since their resource use and costs may not reflect UK practice. Methods We aimed to compare the benefits and costs of short-term treatment (two to eight days with enoxaparin and unfractionated heparin in unstable coronary artery disease. We used published data sources to estimate the incremental cost per quality adjusted life year (QALY, adopting a NHS perspective and using 1998 prices. Results The base case was a 0.013 QALY gain and net cost saving of £317 per person treated with enoxaparin instead of unfractionated heparin. All but one sensitivity analysis showed net savings and QALY gains, the exception (the worst case being a cost per QALY of £3,305. Best cases were a £495 saving and 0.013 QALY gain, or a £317 saving and 0.014 QALY gain per person. Conclusions Enoxaparin appears cost saving compared with unfractionated heparin in patients with unstable coronary artery disease. However, cost implications depend on local revascularisation practice.

  8. Finite element modelling of the common carotid artery in the elderly with physiological intimal thickening using layer-specific stress-released geometries and nonlinear elastic properties.

    Science.gov (United States)

    Esmaeili Monir, Hamed; Yamada, Hiroshi; Sakata, Noriyuki

    2016-09-01

    To investigate the mechanical effects of tissue responses, such as remodelling, in the arteries of the elderly, it is important to evaluate stress in the intimal layer. In this study, we investigated a novel technique to evaluate the effect of layer-specific characteristics on stress in the arterial wall in an elderly subject. We used finite element analysis of a segment of carotid artery with intimal thickening, incorporating stress-released geometries and the stress-strain relationships for three separate wall layers. We correlated the stress-strain relationships and local curvatures of the layers with the stress on the arterial wall under physiological loading. The simulation results show that both the stress-strain relationship and the local curvature of the innermost stress-released layer influence the circumferential stress and its radial gradient. This indicates that intimal stress is influenced significantly by location-dependent intimal remodelling. However, further investigation is needed before conclusive inferences can be drawn. PMID:26710676

  9. Comparative Transcriptome Analysis Identifies CCDC80 as a Novel Gene Associated with Pulmonary Arterial Hypertension

    Science.gov (United States)

    Sasagawa, Shota; Nishimura, Yuhei; Sawada, Hirofumi; Zhang, Erquan; Okabe, Shiko; Murakami, Soichiro; Ashikawa, Yoshifumi; Yuge, Mizuki; Kawaguchi, Koki; Kawase, Reiko; Mitani, Yoshihide; Maruyama, Kazuo; Tanaka, Toshio

    2016-01-01

    Pulmonary arterial hypertension (PAH) is a heterogeneous disorder associated with a progressive increase in pulmonary artery resistance and pressure. Although various therapies have been developed, the 5-year survival rate of PAH patients remains low. There is thus an important need to identify novel genes that are commonly dysregulated in PAH of various etiologies and could be used as biomarkers and/or therapeutic targets. In this study, we performed comparative transcriptome analysis of five mammalian PAH datasets downloaded from a public database. We identified 228 differentially expressed genes (DEGs) from a rat PAH model caused by inhibition of vascular endothelial growth factor receptor under hypoxic conditions, 379 DEGs from a mouse PAH model associated with systemic sclerosis, 850 DEGs from a mouse PAH model associated with schistosomiasis, 1598 DEGs from one cohort of human PAH patients, and 4260 DEGs from a second cohort of human PAH patients. Gene-by-gene comparison identified four genes that were differentially upregulated or downregulated in parallel in all five sets of DEGs. Expression of coiled-coil domain containing 80 (CCDC80) and anterior gradient two genes was significantly increased in the five datasets, whereas expression of SMAD family member six and granzyme A was significantly decreased. Weighted gene co-expression network analysis revealed a connection between CCDC80 and collagen type I alpha 1 (COL1A1) expression. To validate the function of CCDC80 in vivo, we knocked out ccdc80 in zebrafish using the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system. In vivo imaging of zebrafish expressing a fluorescent protein in endothelial cells showed that ccdc80 deletion significantly increased the diameter of the ventral artery, a vessel supplying blood to the gills. We also demonstrated that expression of col1a1 and endothelin-1 mRNA was significantly decreased in the ccdc80-knockout zebrafish. Finally, we examined Ccdc

  10. Comparative studies on the mechanisms of action of four polysaccharides on arterial restenosis.

    Science.gov (United States)

    Deux, Jean-François; Meddahi-Pellé, Anne; Bree, Françoise; Bataille, Isabelle; Michel, Jean-Baptiste; Letourneur, Didier

    2009-01-01

    Percutaneous coronary interventions play a major role in the management of patients affected by coronary artery diseases. However, their efficiency is impaired by restenosis, defined as a reduction of the vessel lumen, occurring a few months after the procedure. A low-molecular-weight fraction of fucoidan, a vegetal heparin-like sulphated polysaccharide, was recently shown to greatly reduce in-stent restenosis after angioplasty in rabbits. To better understand the in vivo anti-restenotic effects of this polymer, we used fractions of fucoidan and compared to heparin and dextran of different sizes. We carried out in vitro growth inhibition experiments on vascular smooth muscle cells, performed an in vivo pharmacokinetic study, and locally delivered fluorescently-labeled polysaccharides in rabbit iliac arteries after angioplasty with a non-occlusive catheter. The results indicated that (i) preparation of well-characterized fractions from natural fucoidan is compulsory for in vitro and in vivo studies, (ii) antiproliferative activity of sulphated polysaccharides on cultured smooth muscle cells is not a major predictive factor for the reduction of restenosis in vivo and (iii) pharmacokinetic parameters and binding of low-molecular-weight fucoidan on angioplasty-induced injured vascular walls are important local and general factors controlling its mechanisms of action. PMID:19323884

  11. Iopamidol 150 in intra-arterial digital angiography of the peripheral vasculature: A comparative study

    International Nuclear Information System (INIS)

    The results of a comparative double-blind clinical trial involving peripheral intra-arterial DSA performed with low iodine iopamidol concentrations (150 and 200 mg. I/ml) are reported. Forty-six patients were examined for vital signs, local (heat and pain sensations) and systemic reactions and monitored throughout the procedure. No untoward effect was observed apart from mild local reactions, which on the other hand did not produce any movement artifacts. Image quality was good to optimal in 98% of the cases. In no case were higher concentrations of contrast medium (cm) needed. No significant differences between the two concentrations of cm used were observed with respect to either contrast ability of tolerability. (orig.)

  12. Decreased pre-surgical CD34+/CD144+ cell number in patients undergoing coronary artery bypass grafting compared to coronary artery disease-free valvular patients

    Directory of Open Access Journals (Sweden)

    Redondo Santiago

    2012-01-01

    Full Text Available Abstract Background Cardiovascular disease has been linked to endothelial progenitor cell (EPC depletion and functional impairment in atherosclerosis and aortic stenosis. EPCs may play a pivotal role in vascular grafting. However, the EPC depletion in coronary artery bypass grafting (CABG patients has not been compared to coronary artery disease-free valvular replacement patients with aortic stenosis. Methods We aimed to assess the basal number of CD34+/KDR+ and CD34+/CD144+ cells in CABG patients, compared to aortic stenosis valvular replacement patients. 100 patients (51 CABG and 49 valvular surgery ones were included in the present study. All CABG or valvular patients had angiographic demonstration of the presence or the absence of coronary artery disease, respectively. Numbers of CD34+/KDR+ and CD34+/CD144+ were assessed by flow cytometry of pre-surgical blood samples. Results We found a lower number of CD34+/CD144+ cells in CABG patients compared to valvular patients (0.21 ± 0.03% vs. 0.47 ± 0.08%, and this difference remained statistically significant after the P was adjusted for multiple comparisons (P = 0.01428. Both groups had more EPCs than healthy controls. Conclusions Pre-surgical CD34+/CD144+ numbers are decreased in CABG patients, compared to valvular patients with absence of coronary disease.

  13. Magnetic resonance imaging compared with echocardiography in the evaluation of pulmonary artery abnormalities in children with tetralogy of Fallot following palliative and corrective surgery

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, S.B.; Crisci, K.L.; Koenig, P.; Robinson, B.; Anisman, P.; Russo, P. [St. Christopher`s Hospital for Children, Front Street at Erie Avenue, Philadelphia, PA 19134 (United States)

    1997-12-01

    Background. Abnormalities of the pulmonary arteries following palliative or corrective surgery for tetralogy of Fallot (TOF) are common. Our purpose was to compare the usefulness of magnetic resonance imaging (MRI) and echocardiography in the post- operative evaluation of the pulmonary arteries in children with TOF. Objective. Our hypothesis was that MRI is more sensitive than echocardiography in the detection of branch pulmonary artery abnormalities in children with TOF. Materials and methods. Pulmonary artery MRI and echocardiography were performed in 20 children following palliative and/or corrective surgery for TOF. MRI and echocardiography were compared in their ability to detect abnormalities of the pulmonary arteries. Angiographic or surgical correlation was available in 15 children. A perfusion scan for confirmation of pulmonary artery patency was available in one additional child. Results. Abnormalities of the branch pulmonary arteries identified by MRI included: absence or occlusion (2), focal stenosis (15), hypoplasia (2), aneurysm (1), and non-confluence (1). Echocardiography could not adequately visualize the right and left branch pulmonary arteries in eight and ten children, respectively. Echocardiography missed stenosis in 13 branch pulmonary arteries, patency of hypoplastic pulmonary arteries in two children, non-confluence of the pulmonary arteries in one child, and a left pulmonary artery aneurysm in one child. Abnormalities identified by MRI were confirmed in 16 children by angiography, surgery or perfusion scan. Conclusion. MRI is more sensitive than echocardiography for the evaluation of branch pulmonary artery abnormalities in children following surgery for TOF. (orig.) With 2 figs., 3 tabs., 11 refs.

  14. Magnetic resonance imaging compared with echocardiography in the evaluation of pulmonary artery abnormalities in children with tetralogy of Fallot following palliative and corrective surgery

    International Nuclear Information System (INIS)

    Background. Abnormalities of the pulmonary arteries following palliative or corrective surgery for tetralogy of Fallot (TOF) are common. Our purpose was to compare the usefulness of magnetic resonance imaging (MRI) and echocardiography in the post- operative evaluation of the pulmonary arteries in children with TOF. Objective. Our hypothesis was that MRI is more sensitive than echocardiography in the detection of branch pulmonary artery abnormalities in children with TOF. Materials and methods. Pulmonary artery MRI and echocardiography were performed in 20 children following palliative and/or corrective surgery for TOF. MRI and echocardiography were compared in their ability to detect abnormalities of the pulmonary arteries. Angiographic or surgical correlation was available in 15 children. A perfusion scan for confirmation of pulmonary artery patency was available in one additional child. Results. Abnormalities of the branch pulmonary arteries identified by MRI included: absence or occlusion (2), focal stenosis (15), hypoplasia (2), aneurysm (1), and non-confluence (1). Echocardiography could not adequately visualize the right and left branch pulmonary arteries in eight and ten children, respectively. Echocardiography missed stenosis in 13 branch pulmonary arteries, patency of hypoplastic pulmonary arteries in two children, non-confluence of the pulmonary arteries in one child, and a left pulmonary artery aneurysm in one child. Abnormalities identified by MRI were confirmed in 16 children by angiography, surgery or perfusion scan. Conclusion. MRI is more sensitive than echocardiography for the evaluation of branch pulmonary artery abnormalities in children following surgery for TOF. (orig.)

  15. Comparative evaluation of despeckle filtering in ultrasound imaging of the carotid artery.

    Science.gov (United States)

    Loizou, Christos P; Pattichis, Constantinos S; Christodoulou, Christodoulos I; Istepanian, Robert S H; Pantziaris, Marios; Nicolaides, Andrew

    2005-10-01

    It is well-known that speckle is a multiplicative noise that degrades the visual evaluation in ultrasound imaging. The recent advancements in ultrasound instrumentation and portable ultrasound devices necessitate the need of more robust despeckling techniques for enhanced ultrasound medical imaging for both routine clinical practice and teleconsultation. The objective of this work was to carry out a comparative evaluation of despeckle filtering based on texture analysis, image quality evaluation metrics, and visual evaluation by medical experts in the assessment of 440 (220 asymptomatic and 220 symptomatic) ultrasound images of the carotid artery bifurcation. In this paper a total of 10 despeckle filters were evaluated based on local statistics, median filtering, pixel homogeneity, geometric filtering, homomorphic filtering, anisotropic diffusion, nonlinear coherence diffusion, and wavelet filtering. The results of this study suggest that the first order statistics filter lsmv, gave the best performance, followed by the geometric filter gf4d, and the homogeneous mask area filter lsminsc. These filters improved the class separation between the asymptomatic and the symptomatic classes based on the statistics of the extracted texture features, gave only a marginal improvement in the classification success rate, and improved the visual assessment carried out by the two experts. More specifically, filters lsmv or gf4d can be used for despeckling asymptomatic images in which the expert is interested mainly in the plaque composition and texture analysis; and filters lsmv, gf4d, or lsminsc can be used for the despeckling of symptomatic images in which the expert is interested in identifying the degree of stenosis and the plaque borders. The proper selection of a despeckle filter is very important in the enhancement of ultrasonic imaging of the carotid artery. Further work is needed to evaluate at a larger scale and in clinical practice the performance of the proposed

  16. Comparing Two Ovulation Induction Methods by Brachial Artery Ultrasonography in Infertile Women with Polycystic Ovary Syndrome

    Directory of Open Access Journals (Sweden)

    B Ghorbani Yekta

    2012-07-01

    Full Text Available Background: Endothelial dysfunction can influence fertility rate in women with polycystic ovary syndrome (PCOS as flow mediated dilatation (FMD is impaired in patients with the disease. The aim of this study was to compare two methods of ovulation induction by letrozole or letrozole plus human menopausal gonadotropins (HMGs in infertile women with PCOS who were resistant to clomiphene citrate based on brachial artery ultrasound findings.Methods: In this double -blind randomized clinical trial, 59 infertile women who had the inclusion criteria for PCOS were evaluated in the Infertility Clinic of Shariati Hospital in Tehran, Iran in 2010-2011. The patients were assigned to two letrozole and letrozole plus HMG groups and were evaluated for FMD in the brachial artery by transvaginal ultrasonography. Later, the values were recorded and analyzed statistically.Results: In the letrozole group, infertility treatment was successful in 15 (57.7% but it failed in 11 (42.3% patients. In letrozole plus HMG group, the treatment was successful in 18 (54.5% while it failed in 15 (45.5% patients. The mean FMD values in the groups with successful and unsuccessful treatment results were 19.42±10% and 18.57±7.2%, respectively, but the difference was not statistically significant (P=0.712. Moreover, the average endometrial thickness in groups with successful and unsuccessful treatment results were 8.4±1.3 mm and 9.8±3.9 mm, respectively but the difference was not significant either (P=0.06.Conclusion: In infertile women with polycystic ovary syndrome that are resistant to clomiphene, letrozole or letrozole combined with gonadotropin can be equally effective for ovulation induction.

  17. Combined intravenous and intra-arterial thrombolytic therapy for acute ischemic stroke: a comparative study with simple intra-arterial thrombolytic therapy

    International Nuclear Information System (INIS)

    Objective: to evaluate the feasibility, efficacy, safety and risk of combined intravenous and local intra-arterial thrombolytic therapy (IV + IA) for ischemic stroke and to compare the results with those obtained by simple intra-arterial thrombolytic therapy (IA). Methods: A total of 46 consecutive patients with ischemic strokes, who were suitable candidates for thrombolytic therapy, were randomly divided into (IV + IA) group (n=24) and IA group (n=22). After the treatment, the arterial recanalization rates, the early clinical improvement, the occurrence of symptomatic intracerebral hemorrhage, the favourable outcome rate and the mortality were evaluated, and the results were compared between the two groups. Results: The average interval between the onset of symptoms and the start of thrombolytic therapy in (IV + IA) group was 255 minutes, which was remarkably lower than that in IA group (310 minutes) with P=0.012. After the thrombolytic therapy, the arterial recanalization rate for (IV + IA) group and IA group was 54.1% and 40.9% respectively (P=0.226). The occurrence of symptomatic intracerebral hemorrhage for (IV + IA) group and IA group was 16.7% and 22.7% respectively (P=0.361). There months after the treatment the favourable outcome rate (modified Rankin Scale, 0 to 2) of (IV + IA) group was 54.2%, which was higher than that of IA group (36.4%), and the mortality in (IV + IA) group and IA group was 8.3% and 9.1% (P=0.927) respectively. No statistically significant difference in recanalization rate and mortality existed between the two groups. Conclusion: This pilot indicates that both (IV + IA) thrombolytic therapy and simple IA thrombolytic therapy are clinically feasible and safe in treating acute ischemic stroke. Compared to simple IA thrombolytic therapy, (IV + IA) thrombolytic therapy is more effective with rather minimal risks. The conclusion of this study needs to be further proved by double-blind and controlled studies with large sample. (authors)

  18. Research related to improved computer aided design software package. [comparative efficiency of finite, boundary, and hybrid element methods in elastostatics

    Science.gov (United States)

    Walston, W. H., Jr.

    1986-01-01

    The comparative computational efficiencies of the finite element (FEM), boundary element (BEM), and hybrid boundary element-finite element (HVFEM) analysis techniques are evaluated for representative bounded domain interior and unbounded domain exterior problems in elastostatics. Computational efficiency is carefully defined in this study as the computer time required to attain a specified level of solution accuracy. The study found the FEM superior to the BEM for the interior problem, while the reverse was true for the exterior problem. The hybrid analysis technique was found to be comparable or superior to both the FEM and BEM for both the interior and exterior problems.

  19. The comparative study of 64-slices spiral CT angiography with DSA in lower extremity arterial occlusive diseases

    International Nuclear Information System (INIS)

    Objective: To study the clinical value of 64-slices spiral CTA with DSA comparatively in diagnosis of lower extremity arterial occlusive diseases. Methods: 31 patients with lower extremity arterial occlusive diseases underwent 64-slice spiral CT angiography of lower extremity arteries and they also underwent digital subtraction angiography (DSA)two weeks later. Reconstruction by maximum intensity projection (MIP), volume render (VR)and multiplanar reformatting (MPR)in working-station was undertaken comparing with the bolus chase DSA and traditional DSA for diagnostic accuracy. Results: The 216 arterial segments of lower extremity were selected, including 157 segments with consistent results in demonstrating degree of stenosis by both examinations. On CT angiography, 5 segmental stenosis were overestimated and 9 were underestimated. When stenosis of detected segments is more than 50%, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CTA were 98.21%, 96.15%, 97.22%, 96.49%, and 98.04%, respectively. Conclusion: 64-slices spiral CT angiography is an effective and reliable method for evaluating the lower extremity arterial occlusive diseases and may provide precious information for planning interventional therapy. (authors)

  20. Comparative finite element analysis of the cranial performance of four herbivorous marsupials.

    Science.gov (United States)

    Sharp, Alana C

    2015-10-01

    Marsupial herbivores exhibit a wide variety of skull shapes and sizes to exploit different ecological niches. Several studies on teeth, dentaries, and jaw adductor muscles indicate that marsupial herbivores exhibit different specializations for grazing and browsing. No studies, however, have examined the skulls of marsupial herbivores to determine the relationship between stress and strain, and the evolution of skull shape. The relationship between skull morphology, biomechanical performance, and diet was tested by applying the finite element method to the skulls of four marsupial herbivores: the common wombat (Vombatus ursinus), koala (Phascolarctos cinereus), swamp wallaby (Wallabia bicolor), and red kangaroo (Macropus rufus). It was hypothesized that grazers, requiring stronger skulls to process tougher food, would have higher biomechanical performance than browsers. This was true when comparing the koala and wallaby (browsers) to the wombat (a grazer). The cranial model of the wombat resulted in low stress and high mechanical efficiency in relation to a robust skull capable of generating high bite forces. However, the kangaroo, also a grazer, has evolved a very different strategy to process tough food. The cranium is much more gracile and has higher stress and lower mechanical efficiency, but they adopt a different method of processing food by having a curved tooth row to concentrate force in a smaller area and molar progression to remove worn teeth from the tooth row. Therefore, the position of the bite is crucial for the structural performance of the kangaroo skull, while it is not for the wombat which process food along the entire tooth row. In accordance with previous studies, the results from this study show the mammalian skull is optimized to resist forces generated during feeding. However, other factors, including the lifestyle of the animal and its environment, also affect selection for skull morphology to meet multiple functional demands. PMID:26193997

  1. A comparative study on transradial vs transfemoral artery access for primary percutaneous coronary intervention in patients with acute myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    傅向华

    2003-01-01

    A comparative study on transradial vs transfemoral artery access for primary percutaneous coronary intervention in patients with acute myocardial infarction!050000$河北医科大学第二医院河北医科大学心脏介入中心@傅向华

  2. The Bahaviour of Non-finite Verbs in Translation: A Comparative Case Study of English, Malay and French

    Directory of Open Access Journals (Sweden)

    Mohamed Abdou Moindjie

    2016-07-01

    Full Text Available Non-finite verbs are verbs which are void of tenses but have definite meanings. Their behaviour in translation may bring about meaning loss or gain. This study is an investigation on their translation behaviour from English into Malay and French.  Analyses are carried out following Toury comparative translation theory for translation modeling. The text used is Shakespeare’s Hamlet; it is a literary text whose findings are expected to be reflexive to other genres.  The analysis reveals that English language use more non-finites verbs than Malay and French; this behaviour is determined by some factors relative to language peculiarity and language norms in terms of translators’ decisions and choices. Although English has historically some impacts on Malay language, it is found that Malay and French share more characteristics than do Malay and English as far as non-finite verb translation is concerned.Keywords: Non-finite verbs, finite verbs, language peculiarities, translatability, translation norms, English- French translation, English-Malay translation

  3. Multi-section CT angiography compared with digital subtraction angiography in diagnosing major arterial hemorrhage in inflammatory pancreatic disease

    International Nuclear Information System (INIS)

    Purpose: Major arterial hemorrhage is an uncommon but serious complication of pancreatitis with high morbidity and mortality. Digital subtraction angiography (DSA) has long been the gold standard for the detection of a visceral artery pseudoaneurysm or for the site of active bleeding in patients with pancreatitis. Multi-section CT angiography is a minimally invasive technique which can provide high-resolution and high-contrast images of the arterial lumen and wall, with a much lower risk of complication and morbidity compared to DSA. The aim of this study was to determine the accuracy of multi-section CT angiography for the diagnosis of arterial complications of inflammatory pancreatitic disease. Materials and methods: A retrospective analysis of all patients undergoing visceral angiography for major bleeding as a complication of pancreatitis between 1998 and 2004 was performed. Twenty-nine studies in 25 patients (20 males, 5 females) with a mean age of 50.9 years (range 11-67 years) were identified where multi-section CT angiography was performed in the 24 h preceding the digital subtraction angiogram. Results: Digital subtraction angiography detected a pseudoaneurysm or contrast extravasation in 19 studies and no bleeding was demonstrated in 9 studies. CT angiography correctly identified the site and type of bleeding in 18 of the 19 positive studies. CT angiography detected extravasation of contrast in one study that was not demonstrated on digital subtraction angiography. The sensitivity and specificity for multi-section CT angiography for the detection of major arterial bleeding on a background of pancreatitis were 0.947 and 0.900, respectively. Conclusion: Multi-section CT angiography is a sensitive and accurate technique for the detection of major arterial hemorrhage in inflammatory pancreatic disease and should be considered as the first investigation in the management of these patients

  4. Multi-section CT angiography compared with digital subtraction angiography in diagnosing major arterial hemorrhage in inflammatory pancreatic disease

    Energy Technology Data Exchange (ETDEWEB)

    Hyare, Harpreet [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom)]. E-mail: hhyare@doctors.org.uk; Desigan, Sharmini [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Nicholl, Helen [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Guiney, Michael J. [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Brookes, Jocelyn A. [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Lees, William R. [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom)

    2006-08-15

    Purpose: Major arterial hemorrhage is an uncommon but serious complication of pancreatitis with high morbidity and mortality. Digital subtraction angiography (DSA) has long been the gold standard for the detection of a visceral artery pseudoaneurysm or for the site of active bleeding in patients with pancreatitis. Multi-section CT angiography is a minimally invasive technique which can provide high-resolution and high-contrast images of the arterial lumen and wall, with a much lower risk of complication and morbidity compared to DSA. The aim of this study was to determine the accuracy of multi-section CT angiography for the diagnosis of arterial complications of inflammatory pancreatitic disease. Materials and methods: A retrospective analysis of all patients undergoing visceral angiography for major bleeding as a complication of pancreatitis between 1998 and 2004 was performed. Twenty-nine studies in 25 patients (20 males, 5 females) with a mean age of 50.9 years (range 11-67 years) were identified where multi-section CT angiography was performed in the 24 h preceding the digital subtraction angiogram. Results: Digital subtraction angiography detected a pseudoaneurysm or contrast extravasation in 19 studies and no bleeding was demonstrated in 9 studies. CT angiography correctly identified the site and type of bleeding in 18 of the 19 positive studies. CT angiography detected extravasation of contrast in one study that was not demonstrated on digital subtraction angiography. The sensitivity and specificity for multi-section CT angiography for the detection of major arterial bleeding on a background of pancreatitis were 0.947 and 0.900, respectively. Conclusion: Multi-section CT angiography is a sensitive and accurate technique for the detection of major arterial hemorrhage in inflammatory pancreatic disease and should be considered as the first investigation in the management of these patients.

  5. Comparing finite difference forward models using free energy based on multiple sparse priors

    OpenAIRE

    Strobbe, Gregor; Lopez, Jose; Montes Restrepo, Victoria Eugenia; van Mierlo, Pieter; Hallez, Hans; Vandenberghe, Stefaan

    2012-01-01

    Due to the ill-posed nature of the EEG source localization problem, the spatial resolution of the reconstructed activity is limited to several centimeters (Baillet, 2001). Advanced forward modeling of the head can contribute to improve the spatial resolution (Hallez, 2007). The boundary element method or BEM is commonly used due to its computation speed. More advanced volume modeling methods, such as finite difference methods or FDM, are computationally more intensive but allow estimating sou...

  6. Comparative study of intraarterial and intravenous thrombolysis with urokinase in canine models of acute pulmonary arterial embolism

    International Nuclear Information System (INIS)

    Objective: To evaluate the efficiency and safety of intraarterial thrombolysis with urokinase (UK)in canine models of acute pulmonary arterial embolism. Methods: 24 Canine models of selective acute pulmonary artery embolism with autologous blood clot were divided randomly into 3 groups(each with 8 dogs): intraarterial thrombolytic group (10 000 u/kg of UK infused in 30 rain), intravenous thrombolytic group (20 000 u/kg of UK infused in 2 h) and control group (100 ml of saline infused in 2 h). The value of pulmonary arterial mean pressure (PAMP), blood gas analysis (PaO2 and PaCO2), coagulation index(PT and APTT)and D-dimer were tested at 2 h, 4 h after the thrombolytic procedure and pulmonary arterial angiography was repeated. Results: Comparing the levels of PAMP, PaO2 and D-dimer, showed significant difference in the 3 groups (P2 and blood supply restores more rapidly than the intravenous one. (authors)

  7. Inflammatory response in patients undergoing uterine artery embolization as compared to patients undergoing conventional hysterectomy

    DEFF Research Database (Denmark)

    Brøchner, A C; Mygil, B; Elle, B;

    2009-01-01

    BACKGROUND: Uterine fibroids are benign tumors seen in 20-40% of women of childbearing age, and these fibroids are usually treated by hysterectomy. During the last decade, embolization of the uterine arteries with polyvinyl alcohol microparticles has become an alternative treatment. PURPOSE: To...

  8. A randomised trial comparing the effect of exercise training and weight loss on microvascular function in coronary artery disease

    DEFF Research Database (Denmark)

    Olsen, Rasmus Huan; Pedersen, Lene Rørholm; Jürs, Anders;

    2015-01-01

    BACKGROUND: Coronary microvascular function is associated with outcome and is reduced in coronary artery disease (CAD) and obesity. We compared the effect of aerobic interval training (AIT) and weight loss on coronary flow reserve (CFR) and peripheral vascular function in revascularised obese CAD...... might impact prognosis of CAD through improvement of coronary microvascular function. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01724567....

  9. Tympanic, Infrared Skin, and Temporal Artery Scan Thermometers Compared with Rectal Measurement in Children: A Real-Life Assessment

    OpenAIRE

    Karel Allegaert, MD, PhD; Kristina Casteels, MD, PhD; Ilse van Gorp, RN; Guy Bogaert, MD, PhD

    2014-01-01

    Introduction: Body temperature measurement in children is of clinical relevance. Although rectal measurement is the gold standard, less invasive tools have become available. We aimed to describe the accuracy of tympanic, infrared skin, or temporal artery scan thermometers compared with rectal measurement to reflect core temperature. Methods: Rectal (Filac 3000; Covidien, Mechelen, Belgium), tympanic (AccuSystem Genius2 Typmanic Infrared Ear Thermometer, Covidien, Mechelen, Belgium), tempor...

  10. COMPARATIVE STUDY OF EXTRACRANIAL CAROTID AND VERTEBRAL ARTERY DOPPLER WITH CONTRAST ENHANCED MR ANGIOGRAPHY IN PATIENTS WITH STROKE

    Directory of Open Access Journals (Sweden)

    Archana

    2016-01-01

    Full Text Available CONTEXT Cerebrovascular accident or stroke is one of the most common causes of death. Ultrasonography of the carotid arteries is an easily available, cost effective, non-invasive method of evaluation. Treatment of stroke depends on reaching the most accurate diagnosis. Accurate and prompt diagnosis is crucial because timely and appropriate therapy can significantly reduce the risk of stroke and long-term sequelae. Several modalities of investigation are available to determine carotid artery status. The value of safe, non-invasive screening test is therefore great. AIMS The purpose of this study is to compare the diagnostic value of extracranial carotid and vertebral artery Doppler and Magnetic Resonance Angiography for the diagnosis of carotid artery pathology in patients with stroke. SETTINGS AND DESIGN The principal appealing points in favour of sonography are patient comfort, accuracy and lack of risk. MR Angiography produces reproducible three dimensional image of carotid bifurcation with good sensitivity for high-grade stenosis. METHODS AND MATERIAL After taking consent, 50 patients presenting with focal neurological deficit underwent Colour Doppler and Gadolinium enhanced MRA examination of the carotid and vertebral arteries at KIMS Hospital, Bangalore, with the help of VOLUSON 730 [WIPRO GE ULTRASOUND MACHINE] and GE SIGNA HDXT 1.5 TESLA 16 CHANNEL MRI. RESULTS The highest incidence of stroke was found in the age group of 50-70 years with male population commonly affected. The various risk factors include family history of stroke, hypertension and diabetes mellitus. Total pathologies were most commonly found on the right side. Most common site for atheromatous plaque was carotid bifurcation. Grading of stenosis was done based on the NASCET criteria and the findings of Doppler and MRA were compared. MRA had a better role than Doppler for detecting 80-99% stenosis. CONCLUSIONS MRA has progressively gained clinical relevance in the

  11. Comparing stochastic point-source and finite-source ground-motion simulations: SMSIM and EXSIM

    Science.gov (United States)

    Boore, D.M.

    2009-01-01

    Comparisons of ground motions from two widely used point-source and finite-source ground-motion simulation programs (SMSIM and EXSIM) show that the following simple modifications in EXSIM will produce agreement in the motions from a small earthquake at a large distance for the two programs: (1) base the scaling of high frequencies on the integral of the squared Fourier acceleration spectrum; (2) do not truncate the time series from each subfault; (3) use the inverse of the subfault corner frequency for the duration of motions from each subfault; and (4) use a filter function to boost spectral amplitudes at frequencies near and less than the subfault corner frequencies. In addition, for SMSIM an effective distance is defined that accounts for geometrical spreading and anelastic attenuation from various parts of a finite fault. With these modifications, the Fourier and response spectra from SMSIM and EXSIM are similar to one another, even close to a large earthquake (M 7), when the motions are averaged over a random distribution of hypocenters. The modifications to EXSIM remove most of the differences in the Fourier spectra from simulations using pulsing and static subfaults; they also essentially eliminate any dependence of the EXSIM simulations on the number of subfaults. Simulations with the revised programs suggest that the results of Atkinson and Boore (2006), computed using an average stress parameter of 140 bars and the original version of EXSIM, are consistent with the revised EXSIM with a stress parameter near 250 bars.

  12. Finite element analysis of vibration energy harvesting using lead-free piezoelectric materials: A comparative study

    Directory of Open Access Journals (Sweden)

    Anuruddh Kumar

    2014-06-01

    Full Text Available In this article, the performance of various piezoelectric materials is simulated for the unimorph cantilever-type piezoelectric energy harvester. The finite element method (FEM is used to model the piezolaminated unimorph cantilever structure. The first-order shear deformation theory (FSDT and linear piezoelectric theory are implemented in finite element simulations. The genetic algorithm (GA optimization approach is carried out to optimize the structural parameters of mechanical energy-based energy harvester for maximum power density and power output. The numerical simulation demonstrates the performance of lead-free piezoelectric materials in unimorph cantilever-based energy harvester. The lead-free piezoelectric material K0.5Na0.5NbO3-LiSbO3-CaTiO3 (2 wt.% has demonstrated maximum mean power and maximum mean power density for piezoelectric energy harvester in the ambient frequency range of 90–110 Hz. Overall, the lead-free piezoelectric materials of K0.5Na0.5NbO3-LiSbO3 (KNN-LS family have shown better performance than the conventional lead-based piezoelectric material lead zirconate titanate (PZT in the context of piezoelectric energy harvesting devices.

  13. Sorafenib and hepatic arterial infusion chemotherapy for unresectable advanced hepatocellular carcinoma: A comparative study

    OpenAIRE

    Hiramine, Yasunari; Uto, Hirofumi; Imamura, Yasushi; Tabu, Kazuaki; BABA, YOSHIROU; HIWAKI, TAKUYA; SHO, YUKIHIKO; TAHARA, KENJI; HIGASHI, HIROFUMI; TAMAI, TUTOMU; Oketani, Makoto; Ido, Akio; Tsubouchi, Hirohito

    2011-01-01

    Sorafenib is a kinase-targeted drug that has high efficacy for advanced hepatocellular carcinoma (HCC). The aim of the present study was to determine whether sorafenib is more effective than hepatic arterial infusion chemotherapy (HAIC) for HCC. Twenty patients treated with sorafenib (sorafenib group) initiated at 800 mg/day and 45 patients treated with HAIC (HAIC group) for unresectable Child-Pugh A advanced HCC were investigated retrospectively. The treatment effect was assessed using the R...

  14. Two-Fluid Mathematical Models for Blood Flow in Stenosed Arteries: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Sankar DS

    2009-01-01

    Full Text Available The pulsatile flow of blood through stenosed arteries is analyzed by assuming the blood as a two-fluid model with the suspension of all the erythrocytes in the core region as a non-Newtonian fluid and the plasma in the peripheral layer as a Newtonian fluid. The non-Newtonian fluid in the core region of the artery is assumed as a (i Herschel-Bulkley fluid and (ii Casson fluid. Perturbation method is used to solve the resulting system of non-linear partial differential equations. Expressions for various flow quantities are obtained for the two-fluid Casson model. Expressions of the flow quantities obtained by Sankar and Lee (2006 for the two-fluid Herschel-Bulkley model are used to get the data for comparison. It is found that the plug flow velocity and velocity distribution of the two-fluid Casson model are considerably higher than those of the two-fluid Herschel-Bulkley model. It is also observed that the pressure drop, plug core radius, wall shear stress and the resistance to flow are significantly very low for the two-fluid Casson model than those of the two-fluid Herschel-Bulkley model. Hence, the two-fluid Casson model would be more useful than the two-fluid Herschel-Bulkley model to analyze the blood flow through stenosed arteries.

  15. Cross-Sectional Elasticity Imaging of Arterial Wall by Comparing Measured Change in Thickness with Model Waveform

    Science.gov (United States)

    Tang, Jiang; Hasegawa, Hideyuki; Kanai, Hiroshi

    2005-06-01

    For the assessment of the elasticity of the arterial wall, we have developed the phased tracking method [H. Kanai et al.: IEEE Trans. Ultrason. Ferroelectr. Freq. Control 43 (1996) 791] for measuring the minute change in thickness due to heartbeats and the elasticity of the arterial wall with transcutaneous ultrasound. For various reasons, for example, an extremely small deformation of the wall, the minute change in wall thickness during one heartbeat is largely influenced by noise in these cases and the reliability of the elasticity distribution obtained from the maximum change in thickness deteriorates because the maximum value estimation is largely influenced by noise. To obtain a more reliable cross-sectional image of the elasticity of the arterial wall, in this paper, a matching method is proposed to evaluate the waveform of the measured change in wall thickness by comparing the measured waveform with a template waveform. The maximum deformation, which is used in the calculation of elasticity, was determined from the amplitude of the matched model waveform to reduce the influence of noise. The matched model waveform was obtained by minimizing the difference between the measured and template waveforms. Furthermore, a random error, which was obtained from the reproducibility among the heartbeats of the measured waveform, was considered useful for the evaluation of the reliability of the measured waveform.

  16. Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom

    Energy Technology Data Exchange (ETDEWEB)

    King, Deirdre M.; Fagan, Andrew J.; Moran, Carmel M.; Browne, Jacinta E. [Medical Ultrasound Physics and Technology Group, School of Physics, Dublin Institute of Technology, Dublin 8 (Ireland); Centre for Advanced Medical Imaging (CAMI), St James' s Hospital, Dublin 8 (Ireland); Department of Medical Physics, University of Edinburgh, Edinburgh EH16 4TJ (United Kingdom); Medical Ultrasound Physics and Technology Group, School of Physics, Dublin Institute of Technology, Dublin 8 (Ireland)

    2011-02-15

    Purpose: A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease. Methods: The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound, magnetic resonance imaging, x-ray computed tomography, and x-ray digital subtraction angiography. The construction materials used were optimized with respect to their ultrasonic speed of sound and attenuation coefficient, MR relaxometry (T{sub 1},T{sub 2}) properties, and Hounsfield number/x-ray attenuation coefficient, with a design capable of tolerating high-pressure pulsatile flow. Fiducial targets, incorporated into the phantoms to allow for registration of images among modalities, were chosen to minimize geometric distortions. Results: High quality distortion-free images of the phantoms with good contrast between vessel lumen, fiducial markers, and background tissue to visualize all stenoses were obtained with each modality. Quantitative assessments of the grade of stenosis revealed significant discrepancies between modalities, with each underestimating the stenosis severity for the higher-stenosed phantoms (70% and 85%) by up to 14%, with the greatest discrepancy attributable to DSA. Conclusions: The design and construction of a range of anatomically realistic renal artery phantoms containing varying degrees of stenosis is described. Images obtained using the main four diagnostic techniques used to detect RAS were free from artifacts and exhibited adequate contrast

  17. Comparative study on triangular and quadrilateral meshes by a finite-volume method with a central difference scheme

    KAUST Repository

    Yu, Guojun

    2012-10-01

    In this article, comparative studies on computational accuracies and convergence rates of triangular and quadrilateral meshes are carried out in the frame work of the finite-volume method. By theoretical analysis, we conclude that the number of triangular cells needs to be 4/3 times that of quadrilateral cells to obtain similar accuracy. The conclusion is verified by a number of numerical examples. In addition, the convergence rates of the triangular meshes are found to be slower than those of the quadrilateral meshes when the same accuracy is obtained with these two mesh types. © 2012 Taylor and Francis Group, LLC.

  18. Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study) : an interim analysis of a randomised controlled trial

    NARCIS (Netherlands)

    Ederle, Joerg; Dobson, Joanna; Featherstone, Roland L.; Bonati, Leo H.; van der Worp, H. Bart; de Borst, Gert J.; Lo, T. Hauw; Gaines, Peter; Dorman, Paul J.; Macdonald, Sumaira; Lyrer, Philippe A.; Hendriks, Johanna M.; McCollum, Charles; Nederkoorn, Paul J.; Brown, Martin M.; Algra, A.; Bamford, J.; Beard, J.; Bland, M.; Bradbury, A. W.; Brown, M. M.; Clifton, A.; Gaines, P.; Hacke, W.; Halliday, A.; Malik, I.; Mas, J. L.; McGuire, A. J.; Sidhu, P.; Venables, G.; Bradbury, A.; Brown, M. M.; Clifton, A.; Gaines, P.; Collins, R.; Molynewc, A.; Naylor, R.; Warlow, C.; Ferro, J. M.; Thomas, D.; Bonati, L. H.; Coward, L.; Dobson, J.; Ederle, J.; Featherstone, R. F.; Tindall, H.; McCabe, D. J. H.; Wallis, A.; Brooks, M.; Chambers, B.; Chan, A.; Chu, P.; Clark, D.; Dewey, H.; Donnan, G.; Fell, G.; Hoare, M.; Molan, M.; Roberts, A.; Roberts, N.; Beiles, B.; Bladin, C.; Clifford, C.; Fell, G.; Grigg, M.; New, G.; Bell, R.; Bower, S.; Chong, W.; Holt, M.; Saunder, A.; Than, P. G.; Gett, S.; Leggett, D.; McGahan, T.; Quinn, J.; Ray, M.; Wong, A.; Woodruff, P.; Foreman, R.; Schultz, D.; Scroop, R.; Stanley, B.; Allard, B.; Atkinson, N.; Cambell, W.; Davies, S.; Field, P.; Milne, P.; Mitchell, P.; Tress, B.; Yan, B.; Beasley, A.; Dunbabin, D.; Stary, D.; Walker, S.; Cras, P.; d'Archambeau, O.; Hendriks, J. M. H.; Van Schil, P.; Bosiers, M.; Deloose, K.; van Buggenhout, E.; De Letter, J.; Devos, V.; Ghekiere, J.; Vanhooren, G.; Astarci, P.; Hammer, F.; Lacroix, V.; Peeters, A.; Verhelst, R.; DeJaegher, L.; Peeters, A.; Verbist, J.; Blair, J-F; Caron, J. L.; Daneault, N.; Giroux, M-F; Guilbert, F.; Lanthier, S.; Lebrun, L-H; Oliva, V.; Raymond, J.; Roy, D.; Soulez, G.; Weill, A.; Hill, M.; Hu, W.; Hudion, M.; Morrish, W.; Sutherland, G.; Wong, J.; Alback, A.; Harno, H.; Ijas, P.; Kaste, M.; Lepantalo, M.; Mustanoja, S.; Paananen, T.; Porras, M.; Putaala, J.; Railo, M.; Sairanen, T.; Soinne, L.; Vehmas, A.; Vikatmaa, P.; Goertler, M.; Halloul, Z.; Skalej, M.; Brennan, P.; Kelly, C.; Leahy, A.; Moroney, J.; Thornton, J.; Koelemay, M. J. W.; Nederkoorn, P. J.; Reekers, J. A. A.; Roos, Y. B. W. E. M.; Hendriks, J. M.; Koudstaal, P. J.; Pattynama, P. M. T.; van der Lugt, A.; van Dijk, L. C.; van Sambeek, M. R. H. M.; van Urk, H.; Verhagen, H. J. M.; Bruininckx, C. M. A.; de Bruijn, S. F.; Keunen, R.; Knippenberg, B.; Mosch, A.; Treurniet, F.; van Dijk, L.; van Overhagen, H.; Wever, J.; de Beer, F. C.; van den Berg, J. S. P.; van Hasselt, B. A. A. M.; Zeilstra, D. J.; Boiten, J.; van Otterloo, J. C. A. de Mol; de Vries, A. C.; Nieholt, G. J. Lycklama A.; van der Kallen, B. F. W.; Blankensteijn, J. D.; De Leeuw, F. E.; Kool, L. J. Schultze; van der Vliet, J. A.; de Borst, G. J.; de Kort, G. A. P.; Kapelle, L. J.; Lo, T. H.; Mali, W. P. Th M.; Moll, F.; van der Worp, H. Bart; Verhagen, H.; Barber, P. A.; Bourchier, R.; Hill, A.; Holden, A.; Stewart, J.; Bakke, S. J.; Krohg-Sorensen, K.; Skjelland, M.; Tennoe, B.; Bialek, P.; Biejat, Z.; Czepiel, W.; Czlonkowska, A.; Dowzenko, A.; Jedrzejewska, J.; Kobayashi, A.; Lelek, M.; Polanski, J.; Kirbis, J.; Milosevic, Z.; Zvan, B.; Blasco, J.; Chamorro, A.; Macho, J.; Obach, V.; Riambau, V.; San Roman, L.; Branera, J.; Canovas, D.; Estela, Jordi; Gimenez Gaibar, A.; Perendreu, J.; Bjorses, K.; Gottsater, A.; Ivancev, K.; Maetzsch, T.; Sonesson, B.; Berg, B.; Delle, M.; Formgren, J.; Gillgren, P.; Kall, T-B; Konrad, P.; Nyman, N.; Takolander, R.; Andersson, T.; Malmstedt, J.; Soderman, M.; Wahlgren, C.; Wahlgren, N.; Binaghi, S.; Hirt, L.; Michel, P.; Ruchat, P.; Bonati, L. H.; Engelter, S. T.; Fluri, F.; Guerke, L.; Jacob, A. L.; Kirsch, E.; Lyrer, P. A.; Radue, E-W; Stierli, P.; Wasner, M.; Wetzel, S.; Bonvin, C.; Kalangos, A.; Lovblad, K.; Murith, N.; Ruefenacht, D.; Sztajzel, R.; Higgins, N.; Kirkpatrick, P. J.; Martin, P.; Adam, D.; Bell, J.; Bradbury, A. W.; Crowe, P.; Gannon, M.; Henderson, M. J.; Sandler, D.; Shinton, R. A.; Scriven, J. M.; Wilmink, T.; D'Souza, S.; Egun, A.; Guta, R.; Punekar, S.; Seriki, D. M.; Thomson, G.; Brennan, A.; Enevoldson, T. P.; Gilling-Smith, G.; Gould, D. A.; Harris, P. L.; McWilliams, R. G.; Nasser, H-C; White, R.; Prakash, K. G.; Serracino-Inglott, F.; Subramanian, G.; Symth, J. V.; Walker, M. G.; Clarke, M.; Davis, M.; Dixit, S. A.; Dolman, P.; Dyker, A.; Ford, G.; Golkar, A.; Jackson, R.; Jayakrishnan, V.; Lambert, D.; Lees, T.; Louw, S.; Macdonald, S.; Mendelow, A. D.; Rodgers, H.; Rose, J.; Stansby, G.; Wyatt, M.; Baker, T.; Baldwin, N.; Jones, L.; Mitchell, D.; Munro, E.; Thornton, M.; Baker, D.; Davis, N.; Hamilton, G.; McCabe, D.; Platts, A.; Tibballs, J.; Beard, J.; Cleveland, T.; Dodd, D.; Gaines, P.; Lonsdale, R.; Nair, R.; Nassef, A.; Nawaz, S.; Venables, G.; Belli, A.; Clifton, A.; Cloud, G.; Halliday, A.; Markus, H.; McFarland, R.; Morgan, R.; Pereira, A.; Thompson, A.; Chataway, J.; Cheshire, N.; Gibbs, R.; Hammady, M.; Jenkins, M.; Malik, I.; Wolfe, J.; Adiseshiah, M.; Bishop, C.; Brew, S.; Brookes, J.; Brown, M. M.; Jaeger, R.; Kitchen, N.; Ashleigh, R.; Butterfield, S.; Gamble, G. E.; McCollum, C.; Nasim, A.; O'Neill, P.; Wong, J.; Edwards, R. D.; Lees, K. R.; MacKay, A. J.; Moss, J.; Rogers, P.

    2010-01-01

    Background Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. Methods The International Carotid

  19. Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial.

    LENUS (Irish Health Repository)

    Ederle, Jörg

    2010-03-20

    Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy.

  20. A randomised trial comparing the effect of exercise training and weight loss on microvascular function in coronary artery disease

    DEFF Research Database (Denmark)

    Olsen, Rasmus Huan; Pedersen, Lene Rørholm; Jürs, Anders;

    2015-01-01

    BACKGROUND: Coronary microvascular function is associated with outcome and is reduced in coronary artery disease (CAD) and obesity. We compared the effect of aerobic interval training (AIT) and weight loss on coronary flow reserve (CFR) and peripheral vascular function in revascularised obese CAD...... patients. METHODS AND RESULTS: Seventy non-diabetic patients (BMI 28-40 kg × m(-2), age 45-75 years) were randomised to 12 weeks' AIT (three weekly sessions lasting 38 min with ≈ 16 min at 85-90% of VO2peak) or low energy diet (LED, 800-1000 kcal/day). Per protocol adherence was defined by training...

  1. Non-invasive continuous arterial pressure and pulse pressure variation measured with Nexfin(®) in patients following major upper abdominal surgery: a comparative study.

    Science.gov (United States)

    de Wilde, R B P; de Wit, F; Geerts, B F; van Vliet, A L; Aarts, L P H J; Vuyk, J; Jansen, J R C

    2016-07-01

    We compared the accuracy and precision of the non-invasive Nexfin(®) device for determining systolic, diastolic, mean arterial pressure and pulse pressure variation, with arterial blood pressure values measured from a radial artery catheter in 19 patients following upper abdominal surgery. Measurements were taken at baseline and following fluid loading. Pooled data results of the arterial blood pressures showed no difference between the two measurement modalities. Bland-Altman analysis of pulse pressure variation showed significant differences between values obtained from the radial artery catheter and Nexfin finger cuff technology (mean (SD) 1.49 (2.09)%, p agreement -2.71% to 5.69%). The effect of volume expansion on pulse pressure variation was identical between methods (concordance correlation coefficient 0.848). We consider the Nexfin monitor system to be acceptable for use in patients after major upper abdominal surgery without major cardiovascular compromise or haemodynamic support. PMID:27291598

  2. Finite Difference Radiative Transfer Model Calculations Compared to Measurements at the Top and Bottom of the Atmosphere

    Science.gov (United States)

    LeCroy, Stuart R.; Whitlock, Charles H.; Suttles, John T.

    1997-01-01

    A finite difference radiative transfer program was developed to handle most anisotropic scattering and reflectance problems encountered in the Earth's atmospheric system. The model has been used to reproduce the radiance received by both satellite and ground based radiation measuring instruments. It accurately replicates the radiance measured by both narrow and wide field-of-view instruments with either narrow or broadband wavelength ranges located on the surface and at satellite altitudes. The output of the finite difference code is compared to the measurements by surface pyranometers and a spectroradiometer aboard a high flying aircraft. The program output is also compared to ERBE measurements aboard the ERBS and NOAA-9 satellites as well as the visible bands aboard the GOES-6 and GOES-7 satellites and AVHRR bands 1 and 2 of the NOAA-9 and NOAA-1 1 satellites. The model is within 0.2 % of the radiance received by pyranometers, within 0.6 % of the ERBE radiances, and within 3 % of the radiances measured by the visible bands of the GOES and NOAA AVHRR radiometers.

  3. Radiotherapy of renal arterial stenosis using percutaneous transluminal angioplasy (PTA) as compared with surgical measures

    International Nuclear Information System (INIS)

    The techniques and findings of percutaneous transluminal angioplasy (PTA) are described. The method was technically applicable in 24 (86%) of 28 cases of renal arterial stenosis. Two clinically quiescent complications are reported. After a mean observation period of 16.7 months, normal blood pressure was recorded in 8 patients, improved blood pressure in 7 patients, and unchanged values in 5 patients. The disturbed renal function observed in 8 patients was found to have returned to normal in 4 cases and improved in 4 cases. PTA is an alternative to surgical revascularisation in the treatment of renovascular hypertension. Owing to its low traumatic effect on the patient, it is recommended as the method of choice. (orig./MG)

  4. Anastomose arterial com fio de polidioxanona e fio de polipropileno. Estudo comparativo em cães Arterial anastomose with polydioxanone and polypropilene suture. Comparative study in dogs

    Directory of Open Access Journals (Sweden)

    Eloísa de Brida Tormena

    2002-03-01

    Full Text Available Este estudo teve por objetivo comparar os efeitos do fio absorvível de polidioxanona com o fio inabsorvível de polipropileno, em anastomoses término-terminais, em artérias femorais de cães. Foram utilizados 20 cães, separados em dois grupos, para observação no 7º e no 30º dia de pós-operatório. Cada cão teve suas artérias femorais seccionadas e aproximadas em um lado com pontos separados de fio de polidioxanona 6-0, e no lado contralateral com o fio de polipropileno 6-0. A escolha do fio foi feita por sorteio, totalizando 40 anastomoses. Para análise estatística dos resultados aplicaram-se os testes de Fisher, Mac Nemar, Wilcoxon, Mann-Witney e o teste T de Student (a ≤ 0,05. Nas avaliações clínicas não foram observadas diferenças significantes entre os fios utilizados. Os resultados obtidos nas avaliações arteriográfica e macroscópica dos segmentos arteriais foram semelhantes, assim como na análise histológica morfológica. Na análise histológica morfométrica o fio de polipropileno apresentou número de células gigantes de corpo estranho significativamente maior que o fio de polidioxanona aos 7 e 30 dias de pós-operatório. Os resultados nos permitem concluir que, apesar da maior reação de corpo estranho observada com o fio de polipropileno, o fio de polidioxanona apresentou resultados semelhantes ao fio de polipropileno, em anastomoses arteriais em cães.The objetive of this study was to compare the effects of the absorbable polidioxanone suture to the nonabsorbable polypropylene suture, in end-to-end anastomoses, using dog’s femoral arteries. Twenty dogs were separated in two groups for observation on the 7th and 30th post-operatory day. Each dog had its femoral arteries seccioned and then aproximated one side with separate stitches of polidioxanone 6-0 suture, and the other side with polypropylene 6-0 suture. For the statistical studies Fisher, Mac nemar, Wilsoxon, Mann-Witney and T of Student tests (a

  5. Comparative Finite Element Analysis of the Effects of Tillage Tool Geometry on Soil Disturbance and Reaction Forces

    Directory of Open Access Journals (Sweden)

    Mohamed Ahmed Elbashir

    2014-04-01

    Full Text Available In this study a comparative finite element analysis was conducted to investigate the effects of tillage tool geometry on soil disturbance and reaction forces. A nonlinear three dimensional finite element model, using ANSYS software, was developed to study the soil cutting process by trapezoidal (T1 and rectangular (T2 flat tools that inclined to the horizontal at three rake angles (R1 = 30°, R2 = 60° and R3 = 90°, therefore a total of six treatments were considered in this analysis. The soil media was assumed as elastic-perfectly plastic material with Drucker-Prager’s model. Results of this study revealed that the maximum vertical soil displaced by T1 is greater than that of T2; hence T1 disturbed the soil better than T2 . Results also showed that a significant reduction in draft force was noticed when cutting the soil with T1 in comparison to T2 . Designing the tool in the form of T1 significantly reduces the surface area of the tool; thus conserving the engineering material.

  6. Comparative safety and tolerability of endothelin receptor antagonists in pulmonary arterial hypertension.

    Science.gov (United States)

    Aversa, Meghan; Porter, Sandra; Granton, John

    2015-05-01

    Pulmonary arterial hypertension (PAH) is a condition that leads to progressive right heart failure and death unless recognized and treated early. Endothelin, a potent endogenous vasoconstrictor, has been identified as an important mediator of PAH. Endothelin receptor antagonists (ERAs) have been associated with an improvement in exercise capacity and time to clinical worsening in patients with Group 1 PAH, and three different ERAs are currently approved for use in this population: bosentan, ambrisentan, and macitentan. While all three ERAs are generally well-tolerated, they each have important adverse effects that need to be recognized and monitored. In particular, they may cause anemia, peripheral edema, and mild cardiac, respiratory, neurologic, and gastrointestinal adverse effects to varying degrees. Although bosentan increases a patient's risk of developing liver transaminitis, ambrisentan and macitentan do not appear to confer the same risk of hepatotoxicity at this time. Important drug-drug interactions, particularly involving other drugs metabolized via the cytochrome P450 pathway, are important to recognize when prescribing ERAs. In this review, we provide a brief overview of the current state of knowledge as it relates to the adverse effect profiles, tolerability, and drug-drug interactions of this class of medication as informed by the results of randomized clinical trials, drug surveillance programs, and regulatory agencies. PMID:25792028

  7. The usefulness of computed tomography angiography comparing to Duplex Doppler Ultrasound in the diagnosis of carotid artery stenosis in patients with cerebral circulation insufficiency symptoms

    International Nuclear Information System (INIS)

    To compare diagnostic usefulness of CT angiography (angioCT) vs. Dupplex Doppler Ultrasound (US) in the evaluation of extracranial internal carotid stenosis. The results of extracranial carotid angioCT and US were compared in 70 cases of patients with cerebral circulation insufficiency syndromes. The degree of stenosis was measured according to NASCET. Correlation, contingency and regression coefficients were used to assess the convergence between angioCT and US. The morphology of atherosclerotic plaque depicted in angioCT was assessed as well, and the results were compared to US. Additionally, in 33 patients cerebral angioCT was performed to exclude surgery contraindications. The value of correlation coefficient, which measures the angioCT vs. US convergence in the assessment of carotid artery stenosis, is 0.96. The results correspond best in following groups of cases: normal arteries and occluded arteries (CC contingency coefficient values are 0.68 and 0.65). A statistically significant dependence occurs also in atherosclerotic plaque morphology imaging (Chi=42.114; p=0.0001; CC=0.636). The high degree of convergence between angioCT and US in assessing the extracranial carotid artery stenosis was recorded. AngioCT is useful as the complementary diagnostic method in cases of difficult anatomy, artery loops or kinking. A precise assessment of 'soft' atherosclerotic plaques morphology is not possible with angioCT, but artery wall calcifications are better depicted with this method. (author)

  8. Thallium-201 myocardial perfusion imaging at rest and during exercise. Comparative sensitivity to electrocardiography in coronary artery disease

    International Nuclear Information System (INIS)

    The sensitivity of myocardial perfusion imaging (MPI) using thallium-201 injected both at rest and during peak exercise was compared to simultaneously recorded 12 lead electrocardiography (ECG) for the detection of transient ischemia in 20 normal subjects and 63 patients with coronary artery disease (CAD). No significant perfusion defects or ECG changes were seen on either the rest or exercise studies in any of the normal subjects. Fifty-six percent of patients with CAD developed new perfusion defects with exercise compared to 38 percent who developed ischemic ST-segment depression (P < 0.02). However, when chest pain and/or ST depression were considered indices of ischemia, the sensitivity of exercise testing and thallium-201 MPI was similar. The increased sensitivity of MPI compared to ST-segment depression on the ECG was due to patients with baseline ECG abnormalities and those who failed to achieve 85 percent of predicted maximum heart rate with exercise. Analysis of the exercise results according to the extent of coronary artery disease revealed a progressive increase in both positive ECGs and MPI with the number of vessels involved. In patients with single vessel disease the MPI was more sensitive than the ECG (P < 0.02). The combination of the rest and exercise ECG, MPI and chest pain during exercise failed to identify 11 percent of patients with CAD. Exercise thallium-201 MPI is a useful adjunct to conventional exercise testing particularly when evaluating patients with abnormal resting ECGs, those who develop ventricular conduction defects or arrhythmias during exercise, and those who fail to achieve their predicted heart rate because of fatigue or breathlessness

  9. Comparing Ovarian Radiation Doses in Flat-Panel and Conventional Angiography During Uterine Artery Embolization: A Randomized Clinical Trial

    International Nuclear Information System (INIS)

    Uterine artery embolization (UAE) is a minimally invasive procedure performed under fluoroscopy for the treatment of uterine fibroids and accompanied by radiation exposure. To compare ovarian radiation doses during uterine artery embolization (UAE) in patients using conventional digital subtraction angiography (DSA) with those using digital flat-panel technology. Thirty women who were candidates for UAE were randomly enrolled for one of the two angiographic systems. Ovarian doses were calculated according to in-vitro phantom study results using entrance and exit doses and were compared between the two groups. The mean right entrance dose was 1586±1221 mGy in the conventional and 522.3±400.1 mGy in the flat panel group (P=0.005). These figures were 1470±1170 mGy and 456±396 mGy, respectively for the left side (P=0.006). The mean right exit dose was 18.8±12.3 for the conventional and 9.4±6.4 mGy for the flat panel group (P=0.013). These figures were 16.7±11.3 and 10.2±7.2 mGy, respectively for the left side (P=0.06). The mean right ovarian dose was 139.9±92 in the conventional and 23.6±16.2 mGy in the flat panel group (P<0.0001). These figures were 101.7±77.6 and 24.6±16.9 mGy, respectively for the left side (P=0.002). Flat panel system can significantly reduce the ovarian radiation dose during UAE compared with conventional DSA

  10. Coronary artery calcium score using electron beam tomography in the patients with acute obstructive coronary arterial disease : comparative study within asymptomatic high-risk group of atherosclerosis and chronic obstructive coronary arterial disease group

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Seok Jong; Choi, Byoung Wook; Choe, Kyu Ok [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    2001-04-01

    To compare, through analysis of the coronary artery calcium (CAC) score and the risk factors for atherosclerosis, the characteristics of acute coronary syndrome between an asymptomatic high-risk group of atherosclerosis patients and a chronic coronary arterial obstructive disease(CAOD) group. The CAC scores of an asymptomatic high-risk group of atherosclerosis patients (group I, n=284), a chronic CAOD croup (group II, n=39) and an acute coronary syndrome group (group III, n=21) were measured by electron beam tomography. Forty-seven patients with CAOD from groups II and III underwent coronary angiography, and we scrutinized age, sex and risk factors including diabetes mellitus, hypertension, obesity, smoking, hypercholesterolemia and low high-density lipoproteinemia. The numbers of stenotic coronary arterial branches and degree of stenosis revealed by coronary angiography were also recorded. We determined the differences between the three groups in terms of CAC score and the risk factors, the relationship between CAC score and risk factors, and the characteristic features of each type of CAOD group. The mean CA score of group III (135.1) was not statistically different from that of group I (135.7) or group II (365.8). Among patients aged below 50, the mean CAC score of group III (127.4) was significantly higher than that of group I (6.2), (p=0.0006). The mean CAC score at the sixth decade was also significantly different between group I(81.5) and group II (266.9). The mean age of group III (54.2 years) was significantly lower than that of group I (58.1 years) (p=0.047) and of group II (60.1) (p=0.022). There was significant correlation between the number of stenotic coronary arterial branches and log(CAC +1) (p<.01). The square root of the CAC score and the maximal degree of stenosis was also well correlated (p<.01). There was no difference in the mean number of risk factors among the three groups, though the incidence of smoking in group III was significantly

  11. Coronary artery calcium score using electron beam tomography in the patients with acute obstructive coronary arterial disease : comparative study within asymptomatic high-risk group of atherosclerosis and chronic obstructive coronary arterial disease group

    International Nuclear Information System (INIS)

    To compare, through analysis of the coronary artery calcium (CAC) score and the risk factors for atherosclerosis, the characteristics of acute coronary syndrome between an asymptomatic high-risk group of atherosclerosis patients and a chronic coronary arterial obstructive disease(CAOD) group. The CAC scores of an asymptomatic high-risk group of atherosclerosis patients (group I, n=284), a chronic CAOD croup (group II, n=39) and an acute coronary syndrome group (group III, n=21) were measured by electron beam tomography. Forty-seven patients with CAOD from groups II and III underwent coronary angiography, and we scrutinized age, sex and risk factors including diabetes mellitus, hypertension, obesity, smoking, hypercholesterolemia and low high-density lipoproteinemia. The numbers of stenotic coronary arterial branches and degree of stenosis revealed by coronary angiography were also recorded. We determined the differences between the three groups in terms of CAC score and the risk factors, the relationship between CAC score and risk factors, and the characteristic features of each type of CAOD group. The mean CA score of group III (135.1) was not statistically different from that of group I (135.7) or group II (365.8). Among patients aged below 50, the mean CAC score of group III (127.4) was significantly higher than that of group I (6.2), (p=0.0006). The mean CAC score at the sixth decade was also significantly different between group I(81.5) and group II (266.9). The mean age of group III (54.2 years) was significantly lower than that of group I (58.1 years) (p=0.047) and of group II (60.1) (p=0.022). There was significant correlation between the number of stenotic coronary arterial branches and log(CAC +1) (p<.01). The square root of the CAC score and the maximal degree of stenosis was also well correlated (p<.01). There was no difference in the mean number of risk factors among the three groups, though the incidence of smoking in group III was significantly

  12. Validation and absolute quantification of MR perfusion compared with CT perfusion in patients with unilateral cerebral arterial stenosis

    International Nuclear Information System (INIS)

    Objective: The aim of the study was to assess absolute quantification of dynamic susceptibility contrast-enhanced magnetic resonance perfusion (MRP) comparing with computed tomography perfusion (CTP) in patients with unilateral stenosis. Materials and methods: We retrospectively post-processed MRP in 20 patients with unilateral occlusion or stenosis of >79% at the internal carotid artery or the middle cerebral artery (MCA). Absolute quantification of MRP was performed after applying the following techniques: cerebrospinal fluid removal, vessel removal, and automatic segmentation of brain to calculate the scaling factors to convert relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) values to absolute values. For comparison between MRP and CTP, we manually deposited regions of interest in bilateral MCA territories at the level containing the body of the lateral ventricle. Results: The correlation between MRP and CTP was best for mean transit time (MTT) (r = 0.83), followed by cerebral blood flow (CBF) (r = 0.52) and cerebral blood volume (CBV) (r = 0.43). There was no significant difference between CTP and MRP for CBV, CBF, and MTT on the lesion side, the contralateral side, the lesion-contralateral differences, or the lesion-to-contralateral ratios (P > 0.05). The mean differences between MRP and CTP were as follows: CBV −0.57 mL/100 g, CBF 2.50 mL/100 g/min, and MTT −0.90 s. Conclusion: Absolute quantification of MRP is possible. Using the proposed method, measured values of MRP and CTP had acceptable linear correlation and quantitative agreement.

  13. Validation and absolute quantification of MR perfusion compared with CT perfusion in patients with unilateral cerebral arterial stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Fang-Ying, E-mail: fychiou@hotmail.com [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); Kao, Yi-Hsuan, E-mail: yhkao@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); Teng, Michael Mu Huo, E-mail: mhteng@gmail.com [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); School of Medicine, National Yang-Ming University, Taipei City, Taiwan (China); Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan (China); Chung, Hsiao-Wen, E-mail: chung@cc.ee.ntu.edu.tw [Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Chang, Feng-Chi, E-mail: fcchang374@gmail.com [School of Medicine, National Yang-Ming University, Taipei City, Taiwan (China); Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan (China); Cho, I-Chieh, E-mail: jessie8030@yahoo.com.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); Chen, Wen-Chun, E-mail: sky7408695@hotmail.com [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China)

    2012-12-15

    Objective: The aim of the study was to assess absolute quantification of dynamic susceptibility contrast-enhanced magnetic resonance perfusion (MRP) comparing with computed tomography perfusion (CTP) in patients with unilateral stenosis. Materials and methods: We retrospectively post-processed MRP in 20 patients with unilateral occlusion or stenosis of >79% at the internal carotid artery or the middle cerebral artery (MCA). Absolute quantification of MRP was performed after applying the following techniques: cerebrospinal fluid removal, vessel removal, and automatic segmentation of brain to calculate the scaling factors to convert relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) values to absolute values. For comparison between MRP and CTP, we manually deposited regions of interest in bilateral MCA territories at the level containing the body of the lateral ventricle. Results: The correlation between MRP and CTP was best for mean transit time (MTT) (r = 0.83), followed by cerebral blood flow (CBF) (r = 0.52) and cerebral blood volume (CBV) (r = 0.43). There was no significant difference between CTP and MRP for CBV, CBF, and MTT on the lesion side, the contralateral side, the lesion-contralateral differences, or the lesion-to-contralateral ratios (P > 0.05). The mean differences between MRP and CTP were as follows: CBV −0.57 mL/100 g, CBF 2.50 mL/100 g/min, and MTT −0.90 s. Conclusion: Absolute quantification of MRP is possible. Using the proposed method, measured values of MRP and CTP had acceptable linear correlation and quantitative agreement.

  14. Comparism of Computer Based Yield Line Theory with Elastic Theory and Finite Element Methods for Solid Slabs

    Directory of Open Access Journals (Sweden)

    J.O. Akinyele

    2011-02-01

    Full Text Available The complexity and conservative nature of the Yield Line Theory and its being an upper bound theory have made many design engineers to jettison the use of the analytical method in the analysis of slabs. Before now, the method has basically been a manual or hand methodwhich some engineers did not see a need for its use since there are many computer based packages in the analysis and design of slabs and other civil engineering structures. This paper presents a computer program that has adopted the yield line theory in the analysis of solid slabs. Two rectangular slabs of the same depth but differentdimensions were investigated. The Yield Line Theory was compared with two other analytical methods namely, Finite Element Method and Elastic Theory Method. The results obtained for a two-way spanning slab showed that the yield line theory is truly conservative, butincreasing the result by 25% caused the moment obtained to be very close to the results of the other two methods. Although it was still conservative, the check for deflections showed that it is reliable and economical in terms of reinforcement provision. For a one way spanning slab the results without any increment falls in between the two other methods with the Elastic method giving a conservative results. The paper concludes that the introduction of a computer-based yield line theory program will make the analytical method acceptable to design engineers in the developing countries of the world.

  15. Bronchopulmonary arterial anastomosis at the precapillary level in human lung. Visualization using CT angiography compared with microangiography of autopsied lung

    International Nuclear Information System (INIS)

    To investigate the interrelationships between the bronchial and pulmonary circulations including the existence of precapillary bronchopulmonary arterial anastomoses, CT of bronchial arteriography (BAG-CT) was performed in 10 patients and BAG-CT during a pulmonary artery block test (PA-block) in 5 patients with lung cancer. Bronchial and pulmonary circulations were evaluated in 5 autopsied normal lungs by injecting silicone rubber with different colors into the bronchial and pulmonary arteries. BAG-CT correlated well with the findings at silicone rubber injection into lung autopsy samples. BAG-CT demonstrated inflow of contrast medium into the pulmonary artery during PA-block in all cases, while no inflow was observed before and following reversal of PA-block. Mixed silicone rubber was observed in the lobar to subsubsegmental bronchial arteries in all cases and in the subsubsegmental pulmonary artery in one case. Precapillary bronchopulmonary arterial anastomoses may exist at the level of the lobar bronchi to the periphery. If either the pulmonary or bronchial circulation is disturbed, flow occurs inside the anastomoses to supplement the other flow, especially flow from the bronchial to the pulmonary arteries via the anastomoses, which occurs within 30 min

  16. Bronchopulmonary arterial anastomosis at the precapillary level in human lung. Visualization using CT angiography compared with microangiography of autopsied lung

    International Nuclear Information System (INIS)

    Purpose: To investigate the interrelationships between the bronchial and pulmonary circulations including the existence of precapillary bronchopulmonary arterial anastomoses. Material and Methods: CT of bronchial arteriography (BAG-CT) was performed in 10 patients and BAG-CT during a pulmonary artery block test (PA-block) in 5 patients with lung cancer. Bronchial and pulmonary circulations were evaluated in 5 autopsied normal lungs by injecting silicone rubber with different colors into the bronchial and pulmonary arteries. Results: BAG-CT correlated well with the findings at silicone rubber injection into lung autopsy samples. BAG-CT demonstrated inflow of contrast medium into the pulmonary artery during PA-block in all cases, while no inflow was observed before and following reversal of PA-block. Mixed silicone rubber was observed in the lobar to subsubsegmental bronchial arteries in all cases and in the subsubsegmental pulmonary artery in one case. Conclusion: Precapillary bronchopulmonary arterial anastomoses may exist at the level of the lobar bronchi to the periphery. If either the pulmonary or bronchial circulation is disturbed, flow occurs inside the anastomoses to supplement the other flow, especially flow from the bronchial to the pulmonary arteries via the anastomoses, which occurs within 30 min. (orig.)

  17. Comparative study of software techniques for 3D mapping of perforators in deep inferior epigastric artery perforator flap planning

    Science.gov (United States)

    Hunter-Smith, David J.; Rozen, Warren Matthew

    2016-01-01

    Background Computed tomographic (CT) angiography (CTA) is widely considered the gold standard imaging modality for preoperative planning autologous breast reconstruction with deep inferior epigastric artery (DIEA) perforator (DIEP) flap. Improved anatomical understanding from CTA has translated to enhanced clinical outcomes. To achieve this, the use of appropriate CT hardware and software is vital. Various CT scanners and contrast materials have been demonstrated to consistently produce adequate scan data. However, the availability of affordable and easily accessible imaging software capable of generating 3D volume-rendered perforator images to clinically useful quality has been lacking. Osirix (Pixmeo, Geneva, Switzerland) is a free, readily available medical image processing software that shows promise. We have previously demonstrated in a case report the usefulness of Osirix in localizing perforators and their course. Methods In the current case series of 50 consecutive CTA scans, we compare the accuracy of Osirix to a commonly used proprietary 3D imaging software, Siemens Syngo InSpace 4D (Siemens, Erlangen, Germany), in identifying perforator number and location. Moreover, we compared both programs to intraoperative findings. Results We report a high rate of concordance with Osirix and Siemens Syngo InSpace 4D (99.6%). Both programs correlated closely with operative findings (92.2%). Most of the discrepancies were found in the lateral row perforators (90%). Conclusions In the current study, we report the accuracy of Osirix that is comparable to Siemens Syngo InSpace 4D, a proprietary software, in mapping perforators. However, it provides an added advantage of being free, easy-to-use, portable, and potentially a superior quality of 3D reconstructed image. PMID:27047778

  18. Arterial spin-labeling MR imaging in moyamoya disease compared with clinical assessments and other MR imaging finings

    Energy Technology Data Exchange (ETDEWEB)

    Noguchi, Tomoyuki, E-mail: tnogucci@radiol.med.kyushu-u.ac.jp [Department of Radiology, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Kawashima, Masatou [Department of Neurosurgery, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Nishihara, Masashi; Hirai, Tetsuyoshi [Department of Radiology, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Matsushima, Toshio [Department of Neurosurgery, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Irie, Hiroyuki [Department of Radiology, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan)

    2013-12-01

    Purpose: Our purpose was to identify the causal factors for the perfusion distribution obtained with ASL-MRI by comparing ASL-MRI with clinical information and other MRI findings in moyamoya disease. Methods: Seventy-one patients with moyamoya disease underwent ASL-MRI and other MRI, including fluid-attenuated inversion recovery imaging (FLAIR) and three-dimensional time-of-flight magnetic resonance angiography (MRA) on 3.0-Tesla MRI system. Cerebral blood flow (CBF) values (ASL values) for the cerebral hemispheres (142 sides) were measured on CBF maps generated by ASL-MRI. Relationships between the ASL values and the following 9 factors were assessed: sex, family history, revascularization surgery, age at MR exam, age at onset, the steno-occlusive severity on MRA (MRA score), degree of basal collaterals, degree of leptomeningeal high signal intensity seen on FLAIR, and size of ischemic or hemorrhagic cerebrovascular accident lesion (CVA score). Results: Patients with a family history had significantly higher ASL values than those without such a history. There were significant negative correlations between ASL values and age at MR exam, MRA score, and CVA score. Conclusions: ASL-MRI may have cause-and-effect or mutual associations with family history, current patient age, size of CVA lesion, and intracranial arterial steno-occlusive severity in Moyamoya disease.

  19. Effect of aliskiren on arterial stiffness, compared with ramipril in patients with mild to moderate essential hypertension

    Institute of Scientific and Technical Information of China (English)

    GUO Jian-qiang; WANG Hong-yi; SUN Ning-ling

    2013-01-01

    Background Aliskiren is a novel blood pressure-lowering agent acting as an oral direct renin inhibitor.The aim of this study was to assess the effect of aliskiren on arterial stiffness,compared with that of ramipril in mild to moderate essential hypertensive patients.Methods Following a two week placebo run-in period,patients with a mean sitting diastolic blood pressure (ms-DBP) >95 and <110 mmHg (1 mmHg=0.133 kPa),and a mean sitting systolic blood pressure (ms-SBP) <180 mmHg were randomly allocated to treatment with aliskiren (150 mg/d,n=20) or ramipril (5 mg/d,n=20) for eight weeks.Blood pressure,plasma renin activity,and the brachial-ankle pulse wave velocity (ba-PWV) were measured before and after eight weeks of treatment.Results Eight weeks of treatment significantly decreased systolic blood pressure and diastolic blood pressure in both the aliskiren group and ramipril group.The hypotensive effect did not differ between the two groups.Plasma renin activity decreased after aliskiren treatment and increased after ramipril treatment.There was no significant difference in baseline ba-PWV between the aliskiren and ramipril groups (P=-0.892).The ba-PWV was significantly reduced in both the aliskiren group (1535 (1405-1666) vs.1464 (1360-1506) cm/s) (P <0.01) and the ramipril group (1544 (1433-1673) vs.1447 (1327-1549) cm/s) (P <0.01).No statistically significant difference was found in the decline of ba-PWV between the two groups (P=0.766).Conclusions The current study revealed that aliskiren (150 mg/d) could ameliorate arterial stiffness and its effect was similar to ramipril (5 mg/d) in mild to moderate hypertensive patients,indicating that in addition to lowering blood pressure,aliskiren had beneficial effect on vascular protection.

  20. Comparative study of myocardial perfusion imaging and 64 multi-slice spiral CT for the diagnosis of coronary artery disease

    International Nuclear Information System (INIS)

    Objective: To compare the diagnostic value of myocardial perfusion imaging (MPI) and 64 multi-slice spiral CT (64-MSCT) for coronary artery disease (CAD). Methods: Fifty-two patients with suspected or known CAD were included in the study. Each patient underwent both stress and rest MPI, MSCT as well as conventional coronary angiography (CAG) within 1 month. The stress and rest MPI were scored by a 5-grade criteria (0-4) based on 17 coronary artery segments. The difference between summed stress and rest scores > 1 was defined as myocardial ischemia. Stenosis in one main vessel or one main branch of the main vessel ≥50% was defined as myocardial ischemia by MSCT. CAG was used as the reference for comparison. Statistical analysis was performed using SPSS 13.0 software. Kappa value was used to test the accordance of MPI and MSCT results. χ2 test was used to evaluate the difference between MPI and MSCT results. Results: The patient-based sensitivity, specificity, positive and negative predictive values and accuracy of MPI and MSCT for the diagnosis of CAD were 86.7% (26/30), 77.3% (17/22),83.9% (26/31), 81.0% (17/21), 82.7% (43/52) and 83.3% (25/30), 86.4% (19/22), 89.3%( 25/28), 79.2% (19/24), 84.6% (44/52), respectively. The vessel-based sensitivity, specificity, positive and negative predictive values and accuracy of MPI and MSCT were 74.5% (38/51), 81.0% (85/105), 65.5% (38/58), 86.7% (85/98), 78.8% (123/156) and 90.2% (46/51), 88.6% (93/105),79.3 % (46/58), 94.9% (93/98), 89.1% (139/156), respectively. There was no statistically significant difference between MPI and MSCT for either patient or lesion-based diagnosis (χ2 =0.44, 0.21, both P>0.05). 96.0% (24/25) patients with both abnormal MPI and MSCT positive were validated by CAG while 83.3% (15/18) patients with both MPI and MSCT negative were excluded by CAG. Conclusions: Both MPI and MSCT are reliable diagnostic modalities for CAD. They also provide complementary diagnostic value to each other. (authors)

  1. Imaging anatomy of dorsal pancreatic artery in patients with diabetes: a comparative study between CTA and DSA

    International Nuclear Information System (INIS)

    Objective: To investigate the clinical value of 64-section CT angiography (CTA) in detecting the origin of dorsal pancreatic artery (DPA). Methods: Ninety-seven consecutive patients with diabetes received transcatheter infusion of autologous bone marrow-derived stem cell transplantation into DPA. Abdominal CTA was performed in 42 patients before angiography. Celiac trunk, splenic, common hepatic and superior mesenteric arteries were reconstructed in order to locate the origin and traveling course of DPA. A routine angiography of both celiac and superior mesenteric arteries was performed for the demonstration of DPA. Further angiography of splenic and gastroduodenal arteries was carried out if necessary. Taking DSA images as the reference standard, the sensitivity, specificity and accuracy of CTA for DPA detection were calculated. Results: DPA was the main supply artery of pancreas in 85.7% patients (36/42). CTA demonstrated the origin of DPA in 35 cases, although one of which was confirmed to be misjudged (false positive). In seven cases CTA could not demonstrate DPA, and DSA proved that 2 of them was misjudged (false negative). The sensitivity,specificity and accuracy of CTA for DPA detection were 94.4%, 83.3% and 92.9%, respectively. Conclusion: 64-section CTA can accurately detect the origin of main supply artery of pancreas, which is of great value in guiding the interventional procedure for pancreatic diseases. (authors)

  2. Acute cerebrovascular incident in a young woman: Venous or arterial stroke? – Comparative analysis based on two case reports

    International Nuclear Information System (INIS)

    Cerebrovascular diseases are the most common neurological disorders. Most of them are arterial strokes, mainly ischemic, less often of hemorrhagic origin. Changes in the course of cerebral venous thrombosis are less common causes of acute cerebrovascular events. Clinical and radiological presentation of arterial and venous strokes (especially in emergency head CT) may pose a diagnostic problem because of great resemblance. However, the distinction between arterial and venous stroke is important from a clinical point of view, as it carries implications for the treatment and determinates patient’s prognosis. In this article, we present cases of two young women (one with an acute venous infarction, the second with an arterial stroke) who presented with similar both clinical and radiological signs of acute vascular incident in the cerebral cortex. We present main similarities and differences between arterial and venous strokes regarding the etiology, clinical symptoms and radiological appearance in various imaging techniques. We emphasize that thorough analysis of CT (including cerebral vessels), knowledge of symptoms and additional clinical information (e.g. risk factors) may facilitate correct diagnosis and allow planning further diagnostic imaging studies. We also emphasize the importance of MRI, especially among young people, in the differential diagnosis of venous and arterial infarcts

  3. Acute cerebrovascular incident in a young woman: Venous or arterial stroke? – Comparative analysis based on two case reports

    Science.gov (United States)

    Sleiman, Katarzyna; Zimny, Anna; Kowalczyk, Edyta; Sąsiadek, Marek

    2013-01-01

    Summary Background Cerebrovascular diseases are the most common neurological disorders. Most of them are arterial strokes, mainly ischemic, less often of hemorrhagic origin. Changes in the course of cerebral venous thrombosis are less common causes of acute cerebrovascular events. Clinical and radiological presentation of arterial and venous strokes (especially in emergency head CT) may pose a diagnostic problem because of great resemblance. However, the distinction between arterial and venous stroke is important from a clinical point of view, as it carries implications for the treatment and determinates patient’s prognosis. Case Report In this article, we present cases of two young women (one with an acute venous infarction, the second with an arterial stroke) who presented with similar both clinical and radiological signs of acute vascular incident in the cerebral cortex. We present main similarities and differences between arterial and venous strokes regarding the etiology, clinical symptoms and radiological appearance in various imaging techniques. Conclusions We emphasize that thorough analysis of CT (including cerebral vessels), knowledge of symptoms and additional clinical information (e.g. risk factors) may facilitate correct diagnosis and allow planning further diagnostic imaging studies. We also emphasize the importance of MRI, especially among young people, in the differential diagnosis of venous and arterial infarcts. PMID:24505227

  4. The influence of thread geometry on biomechanical load transfer to bone: A finite element analysis comparing two implant thread designs

    Directory of Open Access Journals (Sweden)

    Manisha G Herekar

    2014-01-01

    Full Text Available Background: The success of dental implants depends on the manner in which stresses are transferred to the surrounding bone. An important consideration is to design an implant with a geometry that will minimize the peak bone stresses caused by standard loading. The aim of this study was to assess the influence of implant thread geometry on biomechanical load transfer and to compare the difference between two different thread designs. Materials and Methods: A three-dimensional finite element model of D2 bone representing mandibular premolar region was constructed. Two implants of differing thread geometries, 13-mm length, and 4-mm diameter along with superstructures were simulated. One design featured fourfold microthread of 0.4-mm pitch, 0.25-mm depth in the crestal one-third; 0.8-mm pitch, 0.5-mm depth in the apical two-third. The other design had a single-pitch microthread of 0.8-mm pitch, 0.25-mm depth in the crestal one-third; 0.8-mm pitch, 0.5-mm depth in the apical two-third. A static axial load of 100-N was applied to the occlusal surface of the prosthesis. ANSYS CLASSIC 9.0 (PA,USAsoftware was used for stress analysis as von Mises stresses. Results: A comparison of von Mises stresses between two thread designs revealed that fourfold microthread allows better stress distribution within the implant body by 43.85%, abutment by 15.68%, its superstructure by 39.70% and 36.30% within cancellous bone as compared to single-pitch microthread. The effective stress transfer to the cortical bone is lowered by 60.47% with single-pitch microthread. Conclusion: Single-pitch microthread dissipates lesser stresses to cortical bone while the implant body, abutment, and superstructure absorb more stress. This will have a positive influence on the bone-implant contact and contribute to preservation of crestal bone. Implant with single pitch microthread will thus be preferable to be used in areas where the amount of cortical bone available is less.

  5. Comparing the Effects of Morphine Sulfate and Diclofenac Suppositories on Postoperative Pain in Coronary Artery Bypass Graft Patients

    Science.gov (United States)

    Imantalab, Vali; Mirmansouri, Ali; Sedighinejad, Abbas; Naderi Nabi, Bahram; Farzi, Farnoush; Atamanesh, Hadi; Nassiri, Nassir

    2014-01-01

    Background: Simple and efficient way of pain management after Coronary Artery Bypass Graft (CABG) surgery is an important aspect of patients' care. Objectives: This study aimed to compare the effects of morphine and diclofenac suppositories on postoperative pain management. Patients and Methods: In this double-blinded clinical trial study, 120 patients aged 30-65 years old, undergone CABG, were equally divided into two groups of A (morphine) and B (diclofenac). All patients were anesthetized with intravenous fentanyl 10 μg/kg, etomidate 0.2 mg/kg and cisatracurium 0.2 mg/kg. Anesthesia was maintained with oxygen 50% and air 50%, propofol 50 μg/kg/min, fentanyl 1-2 μg/kg/h and atracurium 0.6 mg/kg/h. Analgesics were administered after the operation at intensive care unit (ICU) and Visual Analogue Score (VAS) was evaluated in both groups in 4-hour intervals after extubation for 24 hours. After extubation in case of VAS > 3, morphine suppository 10 mg (group A) or diclofenac suppository 50 mg (group B) was administered for patients. Results: No significant statistical relationship was found between the two groups regarding gender, age, BMI, paracetamol consumption, length of operation time, cardiopulmonary bypass pump (CPB) time, and stay time at ICU (P Value ≥ 0.05). Total dosage of used morphine was 22 ± 8.3 mg in each patient and total dosage of used diclofenac was 94 ± 32.01 mg. Average variation of VAS at measured intervals was significant (P Value ≤ 0.0001), but these variations were not significantly different when comparing the two groups (P Value = 0.023). Conclusions: Both morphine and diclofenac suppositories reduced pain significantly and similarly after CABG surgery. PMID:25346897

  6. Patient Satisfaction After Femoral Arterial Access Site Closure Using the ExoSeal® Vascular Closure Device Compared to Manual Compression: A Prospective Intra-individual Comparative Study

    International Nuclear Information System (INIS)

    PurposeTo intra-individually compare discomfort levels and patient satisfaction after arterial access closure using the ExoSeal® vascular closure device (VCD) and manual compression (MC) in a prospective study design.MethodsPatients undergoing two planned interventions from 07/2013 to 09/2014 could participate in the study. Access closure was performed with an ExoSeal®-VCD in one and MC in the other intervention. Patients were clinically and sonographically examined and were given questionnaires 1 day after intervention [groin- and back-pain during bedrest (100-point visual analog scale; 0: no pain); comfortability of bedrest (10-point Likert scale, 1: comfortable), satisfaction with closure (10-point Likert scale, 1: very satisfied)]. Results were analyzed in a cross-over design.Results48 patients (29 male, median age 62.5 (32–88) years) were included. An ExoSeal®-VCD was used first in 25 cases. As four of these subsequently refused MC as second intervention, data from 44 patients could be analyzed. All closures were technically successful (successful device deployment) without major complications. Groin- and back-pain after VCD-use/MC was 0 (0–15) vs. 10 (0–80) and 0 (0–75) vs. 25 (0–90), respectively (p < 0.0001). Bedrest after VCD-use was more comfortable than after MC [1 (range 1–7) vs. 6 (2–10); p < 0.0001]. Satisfaction with the closure procedure and with the intervention in general was higher after VCD-use compared to MC [1 (1–3) vs. 5 (2–10) and 1 (1–2) vs. 2 (1–4), respectively; p < 0.0001].ConclusionIntra-individual comparison showed pain levels and discomfort to be significantly lower after ExoSeal® use compared to MC. VCD closure was associated with higher satisfaction both with the closure itself and with the intervention in general

  7. Comparative study of dobutamine stress electron-beam computed tomography and exercise thallium scintigraphy in the diagnosis of patients with suspected coronary artery disease

    International Nuclear Information System (INIS)

    To evaluate the diagnostic value of dobutamine stress electron-beam computed tomography (EBCT) as compared with exercise stress thallium-201 single-photon emission computed tomography (201Tl-SPECT) for the detection of myocardial ischemia, 10 patients with proven or suspected coronary artery disease underwent both tests. Nine of the 10 patients also underwent coronary angiography. EBCT images were analyzed objectively to evaluate systolic wall thickening and analyzed segmentally to determine the distribution of the coronary arteries. Dobutamine stress EBCT revealed the presence of ischemia in 59 segments, whereas exercise stress 201Tl-SPECT revealed ischemia in 51 segments (agreement=73%). The advantage of dobutamine stress EBCT was demonstrated in the inferior/posterior segments as compared with the results of exercise stress 201Tl-SPECT. The overall sensitivity for detecting ischemic regions supplied by coronary arteries with significant stenosis (diameter stenosis >50%) was 83% for dobutamine stress EBCT and 79% for exercise stress 201Tl-SPECT (p=NS), with specificities of 75% and 82% (p=NS). Thus, dobutamine stress EBCT presents a reasonable alternative to exercise stress 201Tl-SPECT for the objective assessment of patients with suspected coronary artery disease. (author)

  8. Comparative study on percutaneous coronary intervention of unprotected left main coronary artery disease: transradial versus transfemoral approach

    Directory of Open Access Journals (Sweden)

    Quan-min JING

    2011-11-01

    Full Text Available Objective To compare the safety,feasibility,and clinical efficacy of transradial approach(TRA percutaneous coronary intervention(PCI with transfemoral approach(TFA PCI for unprotected left main coronary artery(ULMCA disease.Methods The current study selected 286 patients who underwent PCI for ULMCA lesions in the General Hospital of Shenyang Military Region between Jan.2007 and Dec.2008,which included 144(TRA group patients with TRA PCI and 142(TFA group with TFA PCI for review analysis.Difference in coronary angiography(CAG,operation success rate,implantation of complex bifurcate lesion stent,X-ray exposure period,contrast agent dosage,local vascular complications,major adverse cardiac events(MACE rate during hospitalization and visiting period,post-PCI ambulation,post-PCI hospitalization period,and the total hospitalization period between the two groups were compared.Results The two groups have similar baseline features.The difference between the TRA and TFA groups in CAG and operation success rate(96.5% and 98.6% for TRA and 92.3% and 97.9% for TFA,respectively has no statistical significance(P=0.116,P=0.641.The difference between the TRA and TFA groups in terms of implantation rate(29.9% vs 26.8% of complex bifurcate lesion stent(crushed,culotte,T stent,exposure period(53.1min±10.42min vs 51.23min±9.80min,and contrast agent dosage(247.66ml±106.98ml vs 267.26ml±136.09ml has no statistical significance(P=0.561,P=0.105,P=0.175.The TRA group has lower local vascular complications(10.4% vs 19.7% than the TFA group(P=0.028.MACE during hospitalization in the TRA group(6.3% is lower than that in the TFA group(12.7%,but the difference has no statistical significance(P=0.066.Neither group has post-PCI myocardial infarction,stroke,or emergency coronary artery bypass grafting.The TRA group has shorter(P < 0.001 post-PCI ambulation period(1.37days±0.62days vs 2.40days±1.45days,post-PCI hospitalization period(4.16days±3.19days vs 7.75days±5.29days

  9. Intra-arterial infusion of MTX for the treatment of cesarean scar pregnancy: a comparative study between different doses

    International Nuclear Information System (INIS)

    Objective: To investigate the effective dose of methotrexate (MTX) via intra-arterial infusion for the treatment of cesarean scar pregnancy. Methods: Thirty-six cases of incisional scar pregnancy at the gestational age of 5-9 weeks received bilateral uterine arterial infusion of MTX. According to the dose of MTX used, the patients were randomly and equally divided into four groups with MTX dose of 60, 100, 150 and 200 mg respectively. After the perfusion was completed the embolization of both uterine arteries with Gelfoam was carried out until the uterine arteries were no longer visualized on DSA. Uterine curettage was conducted within 1-7 days after the treatment. Results: In one week after the procedure, the difference in the decreasing rate of serum β-HCG and progesterone between group 60 mg and group 200 mg was of statistical significance (P 0.05). The hospitalization days of group 60 mg was the longest, while that of group 200 mg was the shortest. Conclusion: The recommended dose of MTX used via intra-arterial infusion in treating cesarean scar pregnancy is 200 mg. The interventional procedure can kill the embryo tissue and quickly lower the serum β-HCG and progesterone levels,it can also shorten the patient's hospitalization time. (authors)

  10. Comparative study of coronary flow reserve, coronary anatomy and results of radionuclide exercise tests in patients with coronary artery disease

    International Nuclear Information System (INIS)

    A comparative assessment of regional coronary flow reserve, quantitative percent diameter coronary stenosis and exercise-induced perfusion and wall motion abnormalities was performed in 39 patients with coronary artery disease. Coronary flow reserve was determined by a digital angiographic technique utilizing contrast medium as the hyperemic agent. Percent diameter stenosis was calculated by an automated quantification program applied to orthogonal cineangiograms. Thallium-201 scintigraphy and radionuclide ventriculography were used to assess regional perfusion and wall motion abnormalities, respectively, at rest and during exercise. In Group A, 19 patients without transmural infarction or collateral vessels, coronary flow reserve was inversely related to percent diameter stenosis (r = -0.61, p less than 0.0001), and scintigraphic abnormalities occurred only in vascular distributions with a coronary flow reserve of less than 2.00. There was a strong relation among abnormal regional exercise results, stenoses greater than 50% and reactive hyperemia of less than 2.00. Patients with multivessel disease, however, often had normal exercise scintigrams in regions associated with greater than 50% stenosis and low coronary flow reserve when other regions had a lower coronary flow reserve or higher grade stenosis, or both. In Group B, 20 patients with angiographically visible collateral vessels, 12 of whom had prior myocardial infarction, coronary flow reserve correlated less well with percent diameter stenosis than in Group A (r = -0.47, p less than 0.004). As in Group A patients, there was a significant relation between abnormal exercise test results and stenoses greater than 50%. However, reactive hyperemia values were generally lower than in Group A, and positive exercise stress results were strongly correlated only with highly impaired flow reserves of 1.3 or less

  11. Evaluation of batroxobin in preventing vascular restenosis in diabetic patients after infrapopliteal arterial angioplasty: a randomized comparative study

    International Nuclear Information System (INIS)

    Objective: To evaluate batroxobin in preventing vascular restenosis in diabetic patients after infrapopliteal arterial angioplasty through comparing the clinical results of the combination use of batroxobin and aspirin with that of simple use of aspirin. Methods: After a successful angioplasty, fifty-two diabetic patients with symptomatic infrapopliteal obstructions were randomly divided into the study group (n=26) and the control group (n=26). Patients in both groups received 100 aspirin everyday, but the patients in study group additionally received 5 IU batroxobin intravenous drip every day for six times. At the end of the follow-up period lasting for 12 months, magnetic resonance angiography (MRA) or Doppler ultrasonic angiography was performed to check the vessels to see if there was any restenosis or reocclusion. The relief degree of clinical symptoms were observed, and both preoperative and postoperative ankle-brachial index (ABI) were regularly determined and compared. Kaplan-Meier curves were constructed to evaluate restenosis/reocclusion-free rate, limb salvage rate and amputation-free rate. Results: During the follow-up period the occurrence of restenosis/reocclusion in study group and control group was 22.0% and 34.5% respectively (P=0.0307). Statistically significant difference in ABI existed between two groups both after the procedure (P<0.05) and at 12 months after the treatment (P=0.0094). Clinical improvement and tissue healing in study group and control group were observed in 23 and 19 patients respectively (P=0.0544). Twelve months after angioplasty, Kaplan-Meier analysis showed that the restenosis/reocclusion-free rate, the limb salvage rate and the amputation-free rate for study group were 74.0%, 96.2% and 84.6% respectively, while they was 54.8%, 92.3% and 84.6% respectively for control group. Conclusion: The results of this study indicate that the use of the clinical therapeutic efficacy and markedly relieve the symptoms, although this

  12. Finite Element Method Modeling of Sensible Heat Thermal Energy Storage with Innovative Concretes and Comparative Analysis with Literature Benchmarks

    OpenAIRE

    Claudio Ferone; Francesco Colangelo; Domenico Frattini; Giuseppina Roviello; Raffaele Cioffi; Rosa di Maggio

    2014-01-01

    Efficient systems for high performance buildings are required to improve the integration of renewable energy sources and to reduce primary energy consumption from fossil fuels. This paper is focused on sensible heat thermal energy storage (SHTES) systems using solid media and numerical simulation of their transient behavior using the finite element method (FEM). Unlike other papers in the literature, the numerical model and simulation approach has simultaneously taken into consideration vario...

  13. COMPARATIVE EVALUATION OF THE ANTIHYPERTENSIVE EFFECT OF PERINDOPRIL AND LOSARTAN POTASSIUM IN PATIENTS WITH ARTERIAL HYPERTENSION AND STENOTIC CORONARY ATHEROSCLEROSIS BEFORE REVASCULARIZATION: AN OPEN RANDOMIZED COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    O. A. Osipova

    2011-01-01

    Full Text Available Aim. To compare effects of perindopril and losartan potassium on the parameters of the ambulatory blood pressure (BP monitoring (ABPM and circadian BP profile in patients with arterial hypertension (HT and stenotic coronary atherosclerosis before myocardium revascularization. Material and methods. 59 patients with HT degree 2-3 at the age of 35-69 were examined. ABPM was performed in all patients. Daily profile was assessed by the degree of nocturnal BP reduction. Patients were randomized to receive perindopril or losartan potassium. Perindopril was administered at dose of 4 mg/day with subsequent rising up to 8 mg/day in next 7 days. The initial dose of losartan potassium was 25 mg with subsequent rising up to 50 mg 2 times a day. Duration of observation was 8 weeks. Results. Perindopril reduced 24-hour and daytime systolic BP (SBP by 17.2% (p<0.0001, nighttime SBP - by 22.5% (p<0.0001, 24-hour and daytime diastolic BP (DBP - by 18.3% and 17.6% (p<0.0001, respectively , nighttime DBP - by 27.2% (p<0.0001. Losartan potassium reduced 24-hour SBP by 25.7% (p<0.0001, daytime SBP - by 23.6% (p<0.0001, night-time SBP – by 25.5% (p<0.0001, 24-hour DBP - by 27.4%, daytime DBP - by 26.3%, nighttime DBP - by 18.5% (p=0.003. Perindopril decreased in number of non-dippers by 24,3% and night-peakers by 5.4% as well as increased in number of dippers by 27% and over-dippers by 2.7%. A number of patients with SAD profile corresponding to non-dipper type was 45.5% more in losartan taking than this when perindopril receiving (p=0.027. Conclusion. In patients with HT and stenotic coronary atherosclerosis perindopril therapy increases a number of patients with normal BP profile before myocardium revascularization.

  14. Arterial Catheterization

    Science.gov (United States)

    ... version AMERICAN THORACIC SOCIETY Patient Information Series Arterial Catheterization An arterial catheter is a thin, hollow tube ... PHYSICIANS: AND COPY Why Do I Need Arterial Catheterization? Common reasons an arterial catheterization is done include: ■ ...

  15. Less invasive coronary artery revascularization with a minimized extracorporeal circulation system: preliminary results of a comparative study with off-pump-procedures

    OpenAIRE

    Wittwer, Thorsten; Sabashnikov, Anton; Rahmanian, Parwis B; Choi, Yeong-Hoon; Zeriouh, Mohamed; Mehler, Thorsten O; Wahlers, Thorsten

    2013-01-01

    Background Coronary-artery-bypass-grafting (CABG) with conventional extracorporeal circulation (CECC) is associated with adverse effects such as systemic inflammatory response leading to a decrease in systemic vascular resistance and hemodynamic instability. Modern "less invasive" procedures have been established recently which potentially avoid negative side effects of CECC. The aim of this study was to compare perioperative outcome following coronary revascularization using either a minimiz...

  16. Sensitivity of 3D Gradient Recalled Echo Susceptibility-Weighted Imaging Technique Compared to Computed Tomography Angiography for Detection of Middle Cerebral Artery Thrombus in Acute Stroke

    OpenAIRE

    Amit Agarwal; Kanupriya Vijay; Krishnamoorthy Thamburaj; Sangam Kanekar; Paul Kalapos

    2014-01-01

    We aimed at comparing the sensitivity of magnetic resonance (MR) susceptibility-weighted imaging (SWI) with computed tomography angiography (CTA) in the detection of middle cerebral artery (MCA) thrombus in acute stroke. Seventy-nine patients with acute MCA stroke was selected using our search engine software; only the ones showing restricted diffusion in the MCA territory on diffusion-weighted images were included. We finally selected 35 patients who had done both MRI (including SWI) and CTA...

  17. Comparative analysis of nodal and edge finite element method for numerical analysis of 3-D magnetostatic systems

    International Nuclear Information System (INIS)

    The possibilities for applying the Finite Element Method (FEM) with gauged magnetic vector potential and the Edge Element Method (EEM) for three-dimensional numerical analysis of magnetostatic systems are analyzed. It is established that the EEM ensures sufficient accuracy for engineering calculations but in some cases its use results in bad convergence. The use of the FEM with gauged magnetic vector potential instead of the EEM is recommended for preliminary calculations of devices with complex geometry and large air gaps between the ferromagnetic parts. (Author)

  18. A comparative study of the effect of coronary atherosclerosis and age on aortic and pulmonary arterial pulse wave velocity

    International Nuclear Information System (INIS)

    The effect of coronary artery disease (CAD) and age on aortic (AO-PWV) and pulmonary arterial pulse wave velocity (PA-PWV) was studied. Aortic and pulmonary arterial pressure were measured at two sites (ascending and abdominal aorta, and the main pulmonary trunk and one of its principle branches, respectively) using a catheter-tip micromanometer in 24 patients divided in two groups. Control group (n=12) consisted of patients with normal coronaries, while the CAD group (n=12) consisted of patients with coronary artery disease estimated by coronary angiography. The interval between these two sites was determined by measuring the withdrawal distance of the microtip-catheter. AO-PWV was significantly higher (p<0.02) in the CAD group (12.0±4.1 m/sec) than in the control group (8.2±2.7 m/sec). There was no significant difference between the two groups in PA-PWV. AO-PWV was significantly (r=0.731, p<0.01) increased with age in the control group, while no significant correlation between the two was observed in the CAD group. There was no significant correlation between PA-PWV and age in control group. The results of this study indicate that only coronary atherosclerosis and age have significant predictive value regarding AO-PWV, but there was no significant correlation with PA-PWV for any of these parameters. The PA-PWV invasively measured in the 12 control subjects in this study was 2.3±0.7 m/sec, which is very close to values reported in the recent literatures using MRI. (author)

  19. A comparative study of intra-arterial and intramuscular administration of phVEGF165 in a chronic ischemic model of rabbit hindlimb

    International Nuclear Information System (INIS)

    To obtain phVEGF165 for angiogenesis and to compare the effects of its intra-arterial and intramuscular administration in a chronic ischemic rabbit hindlimb model. Chronic ischemic models were constructed in the left hindlimb of rabbits and divided into control (n=6), intra-arterial (n=7) and intramuscular groups (n=5). Plasmid DNA (phVEGF165) expressing vascular endothelial growth factor (VEGF) was obtained from HL60 cells, and transfection into CHO cells and western blot analysis of the medium, as well as proliferation assay of CPAE cells were performed. Two weeks after construction of the models, 500μg phVEGF165 was injected into both the left common iliac artery and thigh muscles. Angiography was performed and the number of vessels counted, and ELISA was used to determine the quantity of VEGF in blood samples. Wilcoxon signed rank test was employed for statistical analysis. VEFG165 was expressed on western blot of the culture medium. Proliferation assay showed that optical densities were 0.73±0.043 in the control study and 1.09±0.015 in phVEGF165. The angiographic scores were 1.32±0.13 (pre-gene therapy) and 1.30±0.07 (post-gene therapy) in the control group, 1.42±0.15 and 1.59±0.09 in the intra-arterial group, 1.59±0.27 and 1.14±0.12 in the intramuscular group. The differences were not statistically significant. In the intra-arterial group, serum VEGF levels were 39.96±1.08 pg/ml (pre-gene therapy), 44.99±2.13 pg/ml (4th day), 48.18±1.49 pg/ml (1st week), 45.70±3.77 pg/ml (2nd week), and 46.54±5.47 pg/ml (3rd week), but in the control and intramuscular groups there were no increases. phVEGF165 affected the proliferation of CPAE cells. There was no difference in angiographic scores and serum VEGF levels between intra-arterial and intramuscular administrations

  20. Comparative study of on-pump and off-pump coronary bypass surgery in patients with triple-vessel coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    陈鑫; 徐明; 史宏伟; 穆心伟; 陈振强; 邱志兵

    2004-01-01

    Background Studies on selected patients undergoing off-pump versus on-pump coronary artery bypass surgery have produced inconsistent results, especially in patients with multiple coronary artery disease. This study compared the clinical results of on-pump and off-pump coronary bypass surgery in patients with triple-vessel disease.Methods A total of 300 consecutive isolated, multiple coronary artery bypass grafting (CABG) patients were assigned to the off-pump coronary artery bypass (OPCAB, n=150) or CABG with cardiopulmonary bypass (CCABG, n=150) groups. There were no significant differences regarding degree of angina, history of myocardial infarction or diabetes, and presence of left main coronary artery disease between the two groups. Ejection fraction in the OPCAB group before surgery was lower than in the CCABG group (P<0.01). In addition, more patients had a history of stroke and abnormal renal function preoperatively in the OPCAB group(P< 0.01). In OPCAB patients, single deep pericardial stay suture with a sling snared down was used to expose the target vessels, along with a stabilizer and a coronary shunt. A Medi-Stim Butterfly Flowmeter was used to measure blood flow through grafts in both groups.Results No OPCAB patient was converted to the CCABG group. The average numbers of distal anastomoses and the indexes of completeness of revascularization (ICR) were similar in both groups. Postoperative respiratory support time and the volumes of chest tube drainage and of blood transfusions were less in the OPCAB group than in the CCABG group (both P<0.01). The postoperative incidences of pulmonary dysfunction and renal insufficiency were lower in the OPCAB group than in the CCABG group (both P<0.05). There were no significant differences between the two groups in mortality and other causes of morbidity (periopetative myocardial infarction, stroke, atrial fibrillation). Conclusions OPCAB can be applied to patients with triple-vessel coronary artery disease and can

  1. Finite Element Method Modeling of Sensible Heat Thermal Energy Storage with Innovative Concretes and Comparative Analysis with Literature Benchmarks

    Directory of Open Access Journals (Sweden)

    Claudio Ferone

    2014-08-01

    Full Text Available Efficient systems for high performance buildings are required to improve the integration of renewable energy sources and to reduce primary energy consumption from fossil fuels. This paper is focused on sensible heat thermal energy storage (SHTES systems using solid media and numerical simulation of their transient behavior using the finite element method (FEM. Unlike other papers in the literature, the numerical model and simulation approach has simultaneously taken into consideration various aspects: thermal properties at high temperature, the actual geometry of the repeated storage element and the actual storage cycle adopted. High-performance thermal storage materials from the literatures have been tested and used here as reference benchmarks. Other materials tested are lightweight concretes with recycled aggregates and a geopolymer concrete. Their thermal properties have been measured and used as inputs in the numerical model to preliminarily evaluate their application in thermal storage. The analysis carried out can also be used to optimize the storage system, in terms of thermal properties required to the storage material. The results showed a significant influence of the thermal properties on the performances of the storage elements. Simulation results have provided information for further scale-up from a single differential storage element to the entire module as a function of material thermal properties.

  2. Peripheral Arterial Disease. Contrast-Enhanced 3D MR Angiography of the Lower Leg and Foot Compared with Conventional Angiography

    International Nuclear Information System (INIS)

    Purpose: To determine whether contrast-enhanced 3D MR angiography (CE MRA) could replace digital subtraction angiography (DSA) for the evaluation of atherosclerotic peripheral vascular disease of the lower leg and foot. Material and Methods: Thirty-five patients with symptoms of atherosclerotic disease of the leg were examined prospectively with CE MRA of the foot and the lower legs as well as with DSA from the aorta to the pedal arches. The MRA technique was focused on optimal imaging of the arteries of the foot. Results: The agreement between CE MRA and DSA for grading of stenosis was moderate to good (weighted -values 0.48-0.80). The sensitivity of CE MRA for detection of significant stenosis (50%) was 92% and the specificity was 64% with DSA as gold standard. Conclusion: CE MRA is a fairly accurate method for the demonstration of atherosclerotic disease below the knee including the pedal arches. It can replace DSA for the assessment of distal arteries in patients with impaired renal function. However, image quality and resolution still needs to be improved before CE MRA can become the method of choice in all patients

  3. Peripheral Arterial Disease. Contrast-Enhanced 3D MR Angiography of the Lower Leg and Foot Compared with Conventional Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Cronberg, C.N.; Albrechtsson, U.; Larsson, E.M. [Univ. Hospital, Lund (Sweden). Center for Medical Imaging and Physiology; Sjoeberg, S.; Leander, P.; Lindh, M. [Univ. Hospital, Malmoe (Sweden). Dept. of Diagnostic Radiology; Norgren, L.; Danielsson, P.; Sonesson, B. [Univ. Hospital, Malmoe (Sweden). Dept. of Vascular Surgery

    2003-03-01

    Purpose: To determine whether contrast-enhanced 3D MR angiography (CE MRA) could replace digital subtraction angiography (DSA) for the evaluation of atherosclerotic peripheral vascular disease of the lower leg and foot. Material and Methods: Thirty-five patients with symptoms of atherosclerotic disease of the leg were examined prospectively with CE MRA of the foot and the lower legs as well as with DSA from the aorta to the pedal arches. The MRA technique was focused on optimal imaging of the arteries of the foot. Results: The agreement between CE MRA and DSA for grading of stenosis was moderate to good (weighted -values 0.48-0.80). The sensitivity of CE MRA for detection of significant stenosis (50%) was 92% and the specificity was 64% with DSA as gold standard. Conclusion: CE MRA is a fairly accurate method for the demonstration of atherosclerotic disease below the knee including the pedal arches. It can replace DSA for the assessment of distal arteries in patients with impaired renal function. However, image quality and resolution still needs to be improved before CE MRA can become the method of choice in all patients.

  4. ALL-CERAMIC AND PORCELAIN-FUSED-TO-METAL FIXED PARTIAL DENTURES: A COMPARATIVE STUDY BY 2D FINITE ELEMENT ANALYSES

    OpenAIRE

    Andréa Barreira Motta; Luiz Carlos Pereira; da Cunha, Andréia R.C.C

    2007-01-01

    All-ceramic fixed partial dentures (FPDs) have an esthetic approach for oral rehabilitation. However, metal-ceramic FPDs are best indicated in the posterior area where the follow-up studies found a lower failure rate. This 2D finite element study compared the stress distribution on 3-unit all-ceramic and metal-ceramic FPDs and identified the areas of major risk of failure. Three FPD models were designed: (1) metal-ceramic FPD; (2) All-ceramic FPD with the veneering porcelain on the occlusal a...

  5. A randomized trial comparing the effect of weight loss and exercise training on insulin sensitivity and glucose metabolism in coronary artery disease

    DEFF Research Database (Denmark)

    Pedersen, Lene Rørholm; Olsen, Rasmus Huan; Jürs, Anders;

    2015-01-01

    AIM: The majority of patients with coronary artery disease (CAD) exhibit abnormal glucose metabolism, which is associated with mortality even at non-diabetic glucose levels. This trial aims to compare the effects of a considerable weight loss and exercise with limited weight loss on glucose...... followed by 2-4 weeks' weight maintenance diet. Glucose tolerance, insulin action, β-cell function and suppression of lipolysis were assessed using a 3-h oral glucose tolerance test. ISI-composite and ISI-HOMA (=1/HOMA-IR) were calculated as surrogate measures of whole-body and hepatic insulin sensitivity...

  6. Comparative Finite Element Analysis of Short Implants and Lateralization of the Inferior Alveolar Nerve With Different Prosthesis Heights.

    Science.gov (United States)

    Jayme, Sérgio J; Ramalho, Paulo R; De Franco, Leonardo; Jugdar, Ricardo Elias; Shibli, Jamil Awad; Vasco, Marco A A

    2015-11-01

    The lateralization of the inferior alveolar nerve (LIAN) and short implants are efficient options for rehabilitation of the posterior atrophic mandible. However, the loss of bone leads to prosthesis with greater height and lever effect that in turn can have different impact on treatments. Through the finite element method, the present study tests the hypothesis that conventional implants placed under LIAN and short implants have similar risk of bone loss regarding variable height of the crown and that crown-to-implant ratio is not a reliable resource to evaluate risk in these treatments. Computed tomography scans of mandibles were processed and implants and prosthetic components were reverse engineered for reconstruction of three-dimensional models to simulate 3 elements fixed partial dentures supported by 2 osseointegrated implants. The models of implants were based on MK III implants (Nobel Biocare, Zurich, Switzerland) with 4 mm in diameter by 7 mm in length representing short implants, and 15 mm in length representing implants used in LIAN. The implant/crown ratio for short implants was 1:1.5, 1:2, and 1:2.5 and LIAN models were modeled with exactly the same prosthesis, resulting in implant/crown ratios of 1:0.67, 1:0.89, and 1:1.12. The results partially rejected the hypothesis that LIAN and short implants have similar risk of bone loss, showing that although LIAN results were better in the models evaluated, the variations in height had proportionally similar impact on both treatments and accepted the hypothesis that crown-to-implant ratio was not a reliable resource to evaluate risk. PMID:26491923

  7. Arterial stick

    Science.gov (United States)

    ... the main arteries in the forearm (radial and ulnar arteries). The procedure is done as follows: The ... Arteries also have thicker walls and have more nerves. When the needle is inserted, there may be ...

  8. Variations in the Prevalence of Risk Factors for Coronary Artery Disease in Rio Grande do Sul-Brazil: A Comparative Analysis between 2002 and 2014

    Directory of Open Access Journals (Sweden)

    Iseu Gus

    2015-01-01

    Full Text Available AbstractBackground:Due to the importance of coronary artery disease (CAD, continuous investigation of the risk factors (RFs is needed.Objective:To evaluate the prevalence of RFs for CAD in cities in Rio Grande do Sul State, and compare it with that reported in a similar study conducted in the same cities in 2002.Methods:Cross-sectional study on 1,056 healthy adults, investigating the prevalence and absolute and relative frequencies of the following RFs for CAD: obesity, systemic arterial hypertension (SAH, dyslipidemias, smoking, sedentary lifestyle, diabetes mellitus, and family history, as well as age and sex. Data was collected in 19 cities, host of the Offices of the Regional Coordinators of Health, as in the 2002 study.Results:Twenty-six percent of the sample consisted of older adults and 57% were women. The prevalence of sedentary lifestyle was 44%, history family 50%, smoking 23%, overweight/obesity 68%, dyslipidemia (high cholesterol levels 43%, SAH 40%, and diabetes 11%. When compared to the 2002 study, the prevalence of active smoking and sedentary behavior decreased, whereas the prevalence of hypertension, dyslipidemia and obesity increased. Obesity is the most prevalent RF in women, and SAH the most prevalent in men.Conclusions:The prevalence of RFs for CAD in Rio Grande do Sul State remains high. Hypertension, obesity and dyslipidemia are still prevalent and require major prevention programs. Smoking and physical inactivity have decreased in the state, suggesting the efficacy of related campaigns.

  9. Comparative evaluation of stresses in tooth implant connected fixed partial denture by varying the implant design and position: A 3D finite element study

    Directory of Open Access Journals (Sweden)

    K V Pratheep

    2013-01-01

    Full Text Available Aim: This study aims at evaluating stresses generated in a fixed tooth to implant connected fixed partial denture (FPD by finite element method by varying implant design and position, in unilateral distal extension cases, i.e. for replacing mandibular 1 st and 2 nd molars. Materials and Methods: Four models were created, Model 1-A finite element model (FEA model of a crestal implant-tooth connected metal ceramic FPD with pontic in 36 region. The 35 region simulated the second premolar. Model 2-A FEA model of a basal implant-tooth connected metal ceramic FPD. Model 3-A FEA model of a crestal implant in 36 region connected to tooth 35 and cantilevered posteriorly with pontic in 37 region, made of metal ceramic. Model 4-A FEA model of a basal implant in 36 region connected to tooth 35 and cantilevered posteriorly with pontic in 37 region, made of metal ceramic. A vertical force of 100N directed evenly on the nodes on the occlusal surface of each of the three crowns. The models displayed stress both numerically and by color coding. Results: On comparing models 1 and 2, the model 1 showed comparatively more stresses in crestal bone area of the implant. On comparing models 3 and 4, model 3 showed lesser von misses stress values. Conclusion: In case of tooth implant connected FPDs without any cantilevers, basal implants show better stress distribution when compared to crestal implants. In case of cantilever designs, crestal implant design showed lower stress values, but the difference in stresses were less.

  10. [Comparative analysis of action of beta-phenyl derivatives of glutamic and gamma-aminobutyric acid on cerebral blood flow and cerebrovascular endothelium after irreversible occlusion of the common carotid artery].

    Science.gov (United States)

    Volotova, E V; Kurkin, D V; Mazina, N V; Berestovitskaia, V M; Vasil'eva, O S

    2013-01-01

    A comparative analysis of the effect of phenyl derivatives of glutamic (RGPU-135) and gamma-aminobutyric acid (Phenibut) on cerebral blood flow, vasodilatory endothelial function and the number of circulating endothelial cells desquamated in animals after irreversible occlusion of the common carotid arteries. It was found that animals treated prophylactically by RGPU-135, after occlusion of the common carotid arteries have higher cerebral blood flow and lower the severity of endothelial dysfunction than in animals treated with Phenibut. PMID:24003482

  11. A comparative study between TL-201 SPECT myocardial perfusion scintigraphy and dobutamine stress echocardiography in the detection of coronary artery disease at the Philippine Heart Center

    International Nuclear Information System (INIS)

    Although thallium-201 SPECT myocardial perfusion scintigraphy (MPS) has shown considerable accuracy for the detection of coronary artery disease (CAD), dobutamine stress echocardiography (DSE), a relatively new method for the detection of CAD had been recently utilized at the Philippine Heart Center. To assess its diagnostic worth versus that of thallium-201 spect myocardial scintigraphy (MPS), we studied 18 patients who underwent both procedures. Coronary angiography (CA) was used as the gold standard. MPS was performed with maximal treadmill exercise or with dipyridamole (0.568 mg/kg over 4 minutes) and Tl-201 was injected at peak stress. DSE was performed by infusing dobutamine at an increment of 5 μg/kg/min up to a maximum of 40. Atropine (0.01%) was added when 85% of maximum predicted heart rate is not achieved. Significant stenosis (>70%) was found in 16 out of 18 patients by CA. The sensitivity for the presence of CAD was 88% (14/16) and 69% (11/16) for MPS and DSE respectively. Specificity was 100% (2/2) for both. PPV was 100% for both while NPV was 50% and 29% for MPS and DSE respectively. Diagnostic accuracies were 89% and 72% for MPS and DSE respectively (P>0.05). Sensitivity for detecting left anterior descending artery (LAD) lesion was 71% 64% for MPS and DSE respectively; specificity was 75% and 100% respectively. For the left circumplex artery (LCX) lesion, both MPS and DSE had a sensitivity of 62% and specificity of 60%. Likewise for the right coronary artery (RCA) lesion, both had a sensitivity of 66% and specificity of 50%. Diagnostic accuracies were equal for both tests at 72% for LAD; 61% for LCX; and 61% for RCA. Kappa tests for association shows ρ values of >0.05 for overall and individual CAD detection suggesting no significant difference between MPS and DSE. Although there is a trend showing better detection of CAD with MPS, this particular study shows that both tests are comparable with regards to detection of the presence of CAD and of

  12. Comparative Study of Compensatory Liver Regeneration in a Rat Model: Portal Vein Ligation Only versus Sequential Ligation of the Portal Vein and Hepatic Artery

    International Nuclear Information System (INIS)

    To compare the volume change and the regenerative capacity between portal vein ligation (embolization) (PVL) and heterochronous PVL with hepatic artery ligation (HAL) in a rodent model. The animals were separated into three groups: group I, ligation of the left lateral and median portal vein branches; group II, completion of PVL, followed by ligation of the same branches of the hepatic artery after 48 h; control group, laparotomy without ligation was performed. Five rats from each group were sacrificed on 1, 3, 5, and 7 days after the operation. Volume change measurement, liver function tests and immunohistochemical analysis were performed. The volume of the nonligated lobe between groups I and II was not significantly different by day 5 and day 7. Mean alanine aminotransferase and total bilirubin levels were significantly higher in group II, while the albumin level was higher in group I. Both c-kit- and MIB-5-positive cells used in the activity detection of regeneration were more prevalent in group I on day 1, 3, and 5, with statistical significance. There was no operation related mortality. PVL alone is safe and effective in compensatory liver regeneration. Performing both PVL and HAL does not confer any additional benefits.

  13. Comparative Analysis of Two Proposed Models of Connecting rods for Crank-rocker Engines Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Mohammed Salah Eldin

    2014-07-01

    Full Text Available In this study, static load analysis was performed on two proposed models of connecting rods (conventional and Y-shape con-rod intended for use in the crank-rocker engine. The analysis was done by modeling the model using CATIA V5 software which was then analyzed using ANSYS Workbench 14.0 software. A static analysis was done to determine the von-misses stresses under tensile and compressive loading conditions. Two cases were studied, firstly, the load was applied at the rocker pin end and fixed at the crank end as a compressive load, and secondly, the load was applied at the same position as a tensile load with both cases under the same constant load. It was found from the analysis that the conventional connecting rod has yielded lower stress values for both cases as compared to the Y-shaped connecting rod. Based on the results, it was concluded that the normal connecting rod is better to be used for the crank-rocker engine.

  14. Finite Automation

    OpenAIRE

    2005-01-01

    This self-paced narrated tutorial covers the following about Finite Automata: Uses, Examples, Alphabet, strings, concatenation, powers of an alphabet, Languages (automata and formal languages), Deterministic finite automata (DFA) SW4600 Automata, Formal Specification and Run-time Verification

  15. Diagnostic performance of cardiac imaging methods to diagnose ischaemia-causing coronary artery disease when directly compared with fractional flow reserve as a reference standard

    DEFF Research Database (Denmark)

    Danad, Ibrahim; Szymonifka, Jackie; Twisk, Jos W R; Norgaard, Bjarne L; Zarins, Christopher K; Knaapen, Paul; Min, James K

    2016-01-01

    diagnosis of ischaemic coronary artery disease (CAD) were included. Twenty-three articles reporting on 3788 patients and 5323 vessels were identified. Meta-analysis was performed for pooled sensitivity, specificity, likelihood ratios (LR), diagnostic odds ratio, and summary receiver operating characteristic......-vessel specificity was highest for MRI (85%, 79-89), FFRCT (78%: 78-81), and SPECT (75%: 69-80), whereas ICA (66%: 64-68) and CCTA (58%: 55-61) yielded a lower specificity. CONCLUSIONS: In this meta-analysis comparing cardiac imaging methods directly to FFR, MRI had the highest performance for diagnosis of ischaemia......AIMS: The aim of this study was to determine the diagnostic performance of single-photon emission computed tomography (SPECT), stress echocardiography (SE), invasive coronary angiography (ICA), coronary computed tomography angiography (CCTA), fractional flow reserve (FFR) derived from CCTA (FFRCT...

  16. Comparative Analysis of Modeling a High-Current Relativistic Charged-Particle Beam in a Diode with Magnetic Insulation Using the Finite-Difference Method and the Large-Particle Method

    Science.gov (United States)

    Bogdanovich, B. Yu.; Nesterovich, A. V.; Sukhanova, L. A.; Khlestkov, Yu. A.

    2014-08-01

    Results of modeling of a high-current relativistic beam by the finite-difference method are compared with results obtained for a beam with the same parameters using the well-known KARAT code, which is based on the large-particle method. These two methods give similar results, which justifies the use of the finite-difference method for the numerical solution of the equations of motion describing the motion of the beam in its own and an external electromagnetic field.

  17. A Randomized Controlled Trial Comparing Suture-Fixation Mucopexy and Doppler-Guided Hemorrhoidal Artery Ligation in Patients with Grade III Hemorrhoids.

    Science.gov (United States)

    Zhai, Min; Zhang, Yong-An; Wang, Zhen-Yi; Sun, Jian-Hua; Wen, Jie; Zhang, Qi; Li, Jin-De; Wu, Yi-Zheng; Zhou, Feng; Xu, Hui-Lei

    2016-01-01

    Background. We aimed to evaluate the effectiveness of a suture-fixation mucopexy procedure by comparing with Doppler-guided hemorrhoidal artery ligation (DGHAL) in the management of patients with grade III hemorrhoids. Methods. This was a randomized controlled trial. One hundred patients with grade III hemorrhoids were randomly assigned to receive suture-fixation mucopexy (n = 50) or DGHAL (n = 50). Outcome assessments were performed at 2 weeks, 12 months, and 24 months. Assessments included resolution of clinical symptoms, postoperative complications, duration of hospitalization, and total costs. Results. At 2 weeks, one (2%) patient in suture-fixation group and four (8%) patients in DGHAL group had persistent prolapsing hemorrhoids. Postoperative bleeding was observed in two patients (4%) in suture-fixation group and one patient in DGHAL group. There was no significant difference in short-term recurrence between groups. Postoperative complications and duration of hospitalization were comparable between the two groups. Rates of recurrence of prolapse or bleeding at 12 months did not differ between groups. However, recurrence of prolapse at 24 months was significantly more common in DGHAL group (19.0% versus 2.3%, p = 0.030). Conclusions. Compared with DGHAL, the suture-fixation mucopexy technique had comparable short-term outcomes and favorable long-term outcomes. PMID:27066071

  18. Efficacy and safety of radiofrequency ablation combined with transcatheter arterial chemoembolization for hepatocellular carcinomas compared with radiofrequency ablation alone: A time to event meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin; Hu, Yanan; Ren, Mudan; Lu, Xin Lan; Lu, Gui Fang; He, Shui Xiang [Dept. of Gastroenterology, First Affiliated Hospital of Xi' an Jiaotong University, Xi' an (China)

    2016-02-15

    To compare the efficacy and safety of combined radiofrequency ablation (RFA) and transcatheter arterial chemoembolization (TACE) with RFA alone for hepatocellular carcinomas (HCC). Randomized controlled trial (RCT) studies that compared the clinical or oncologic outcomes of combination therapy of TACE and RFA versus RFA for the treatment of HCC were identified through literature searches of electronic databases (Pubmed, Embase, Cochrane Library, China Biology Medicine disc, China National Knowledge Infrastructure, and Google Scholar). Hazard ratios (HRs) or odds ratios (ORs) with their corresponding 95% confidence interval (CI) were combined as the effective value to assess the summary effects. The strength of evidence was rated by the Grading of Recommendations Assessment, Development, and Evaluation system. Six RCTs with 534 patients were eligible for inclusion in this meta-analysis. The meta-analysis showed that the combination of TACE and RFA is associated with a significantly longer overall survival (HR = 0.62, 95% CI: 0.49-0.78, p < 0.001) and recurrence-free survival (HR = 0.55, 95% CI: 0.40-0.76, p < 0.001) in contrast with RFA monotherapy. The seemingly higher incidence of major complications in the combination group compared with RFA group did not reach statistical significance (OR = 1.17, 95% CI: 0.39-3.55, p = 0.78). In patients with HCC, the combination of TACE and RFA is associated with significantly higher overall survival and recurrence-free survival, as compared with RFA monotherapy, without significant difference in major complications.

  19. Comparative vascular responses three months after paclitaxel and everolimus-eluting stent implantation in streptozotocin-induced diabetic porcine coronary arteries

    Directory of Open Access Journals (Sweden)

    Sheehy Alexander

    2012-06-01

    Full Text Available Abstract Background Diabetes remains a significant risk factor for restenosis/thrombosis following stenting. Although vascular healing responses following drug-eluting stent (DES treatment have been characterized previously in healthy animals, comparative assessments of different DES in a large animal model with isolated features of diabetes remains limited. We aimed to comparatively assess the vascular response to paclitaxel-eluting (PES and everolimus-eluting (EES stents in a porcine coronary model of streptozotocin (STZ-induced type I diabetes. Method Twelve Yucatan swine were induced hyperglycemic with a single STZ dose intravenously to ablate pancreatic β-cells. After two months, each animal received one XIENCE V® (EES and one Taxus Liberte (PES stent, respectively, in each coronary artery. After three months, vascular healing was assessed by angiography and histomorphometry. Comparative in vitro effects of everolimus and paclitaxel (10-5 M–10-12 M after 24 hours on carotid endothelial (EC and smooth muscle (SMC cell viability under hyperglycemic (42 mM conditions were assayed by ELISA. Caspase-3 fluorescent assay was used to quantify caspase-3 activity of EC treated with everolimus or paclitaxel (10-5 M, 10-7 M for 24 hours. Results After 3 months, EES reduced neointimal area (1.60 ± 0.41 mm, p vs. 0.08 ± 0.05, greater medial necrosis grade (0.52 ± 0.26 vs. 0.0 ± 0.0, and persistently elevated fibrin scores (1.60 ± 0.60 vs. 0.63 ± 0.41 with PES compared to EES (p In vitro, paclitaxel significantly increased (p -7 M, while everolimus did not affect EC/SMC apoptosis/necrosis within the dose range tested. In ECs, paclitaxel (10-5 M significantly increased caspase-3 activity (p  Conclusion After 3 months, both DES exhibited signs of delayed healing in a STZ-induced diabetic swine model. PES exhibited greater neointimal area, increased inflammation, greater medial necrosis, and

  20. A comparative study of smart passive piezoelectric structures interacting with electric networks: Timoshenko beam theory versus finite element plane stress calculations

    International Nuclear Information System (INIS)

    The present paper is devoted to the coupling between mechanical, piezoelectric and electric fields in piezoelastic beams whose electrodes are connected by electric circuits with arbitrary impedances. Taking advantage of the linear piezoelectric constitutive relations, the kinematic assumptions according to Timoshenko, the Gauss law of electrostatics as well as Kirchhoff's voltage rule, the equations of motion for lateral vibrations are derived in the Laplace domain considering the direct and converse piezoelectric effects. For beams with layerwise constant width, the governing equations are similar to the well-known Timoshenko beam equations, but the bending moment is extended by a so-called induced electric moment, which is influenced by the electric circuits. In order to demonstrate the interaction of mechanical and electrical fields, the theory that we develop is compared against plane stress finite element computations using ANSYS. For flexural vibrations with various mechanical boundary conditions and electric impedances, an eigenfrequency analysis is performed and mechanical and electrical field variables are compared for different harmonic excitations

  1. Drugs and lifestyle for the treatment and prevention of coronary artery disease: comparative analysis of the scientific basis

    OpenAIRE

    P.L. da Luz; Nishiyama, M.; A.C.P. Chagas

    2011-01-01

    In this article, we compare two strategies for atherosclerosis treatment: drugs and healthy lifestyle. Statins are the principal drugs used for the treatment of atherosclerosis. Several secondary prevention studies have demonstrated that statins can significantly reduce cardiovascular events including coronary death, the need for surgical revascularization, stroke, total mortality, as well as fatal and non-fatal myocardial infarction. These results were observed in both men and women, the eld...

  2. Arterial Ageing

    OpenAIRE

    Lee, Seung-Jun; Park, Sung-Ha

    2013-01-01

    Arterial ageing is characterized by age associated degeneration and sclerosis of the media layer of the large arteries. However, besides ageing, clinical conditions, which enhance oxidative stress and inflammation act to accelerate the degree of arterial ageing. In this review, we summarized the pathophysiology and contributing factors that accelerate arterial ageing. Among them, we focused on hypertension, the renin-angiotensin-aldosterone system and vascular inflammation which are modifiabl...

  3. Embolization of the Gastroduodenal Artery Before Selective Internal Radiotherapy: A Prospectively Randomized Trial Comparing Standard Pushable Coils with Fibered Interlock Detachable Coils

    International Nuclear Information System (INIS)

    The purpose of this study was compare embolization of the gastroduodenal artery (GDA) using standard pushable coils with the Interlock detachable coil (IDC), a novel fibered mechanically detachable long microcoil, in patients scheduled for selective internal radiotherapy (SIRT). Fifty patients (31 male and 19 female; median age 66.6 ± 8.1 years) were prospectively randomized for embolization using either standard coils or IDCs. Procedure time, radiation dose, number of embolization devices, complications, and durability of vessel occlusion at follow-up angiography were recorded. The procedures differed significantly in time (14:32 ± 5:56 min for standard coils vs. 2:13 ± 1:04 min for IDCs; p < 0.001); radiation dose for coil deployment (2479 ± 1237 cGycm² for standard coils vs. 275 ± 268 cGycm² for IDCs; p < 0.001); and vessel occlusion (17:18 ± 6:39 min for standard coils vs. 11:19 ± 7:54 min for IDCs; p = 0.002). A mean of 6.2 ± 1.8 coils (n = 27) were used in the standard coil group, and 1.3 ± 0.9 coils (p < 0.0001) were used in the IDC group (n = 23) because additional pushable coils were required to achieve GDA occlusion in 4 patients. In 2 patients, the IDC could not be deployed through a Soft-VU catheter. One standard coil dislodged in the hepatic artery and was retrieved. Vessel reperfusion was noted in only 1 patient in the standard coil group. Controlled embolization of the GDA with fibered IDCs was achieved more rapidly than with pushable coils. However, vessel occlusion may not be obtained using a single device only, and the use of sharply angled guiding catheters hampered coil pushability.

  4. Comparison of an Additional Transdermal Fentanyl Patch Compared to Intravenous NSAID and Opioid Analgesics within 24 Hours of an Uterine Artery Embolization for Myoma and Adenomyosis

    Energy Technology Data Exchange (ETDEWEB)

    Song, Suk Yun; Kang, Byung Chul; Rho, Kyung Min [Dept. of Radiology, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of)

    2011-05-15

    To evaluate the effectiveness of an additional transdermal fentanyl patch compared to intravenous analgesics in pain control during the 24-hour period following uterine artery embolization (UAE) for myoma and adenomyosis. Between September 2009 and August 2010, 42 patients underwent UAE for myoma or adenomyosis. Of these, 21 received an intravenous opioid (pethidine) and a nonsteroidal anti-inflammatory drug (group A), and 21 received an additional transdermal fentanyl patch (group B). Pain perception levels were established verbally on a 0-10 scale during the 24-hour period following UAE. Differences in pain trends, mean dose of intravenous pethidine, and adverse effects were compared between the two groups. Pain perception was most severe at 6 hours after UAE and the mean pain level of group B at that time was 6.3 {+-} 0.7, which was significantly lower than that of group A, 8.2 {+-} 0.7 (p<0.05). The mean dose of intravenous pethidine was 114.3 {+-} 59.5 mg in group A and 90.5 {+-} 49.0 mg in group B, while the incidence of nausea was 67% in group A and 77% in group B. In both cases, the differences were not significantly different (p>0.05), and no evidence of respiratory distress was demonstrated. The addition of a transdermal fentanyl patch to intravenous analgesics is effective in reducing post-embolization pain during the 24-hour period after UAE.

  5. Comparison of an Additional Transdermal Fentanyl Patch Compared to Intravenous NSAID and Opioid Analgesics within 24 Hours of an Uterine Artery Embolization for Myoma and Adenomyosis

    International Nuclear Information System (INIS)

    To evaluate the effectiveness of an additional transdermal fentanyl patch compared to intravenous analgesics in pain control during the 24-hour period following uterine artery embolization (UAE) for myoma and adenomyosis. Between September 2009 and August 2010, 42 patients underwent UAE for myoma or adenomyosis. Of these, 21 received an intravenous opioid (pethidine) and a nonsteroidal anti-inflammatory drug (group A), and 21 received an additional transdermal fentanyl patch (group B). Pain perception levels were established verbally on a 0-10 scale during the 24-hour period following UAE. Differences in pain trends, mean dose of intravenous pethidine, and adverse effects were compared between the two groups. Pain perception was most severe at 6 hours after UAE and the mean pain level of group B at that time was 6.3 ± 0.7, which was significantly lower than that of group A, 8.2 ± 0.7 (p0.05), and no evidence of respiratory distress was demonstrated. The addition of a transdermal fentanyl patch to intravenous analgesics is effective in reducing post-embolization pain during the 24-hour period after UAE.

  6. COMPARATIVE EFFICACY OF LONG-TERM ANTIHYPERTENSIVE MONOTHERAPY IN PATIENTS WITH ARTERIAL HYPERTENSION AT THE WORK PLACE

    Directory of Open Access Journals (Sweden)

    О. N. Antropova

    2016-01-01

    Full Text Available Aim. To compare effects of 12-month monotherapy with nebivolol, enalapril and indapamide on blood pressure (BP, left ventricular hypertrophy and quality of life in the locomotive engineers and their assistants with stress-associated hypertension at the work place (HTwp.Material and methods. 96 locomotive engineers (20- 53 y.o and their assistants with HTwp were observed. The patients were randomized to receive nebivolol (1 group, enalapril (2 group or indapamide (3 group. 24-hour BP monitoring, echocardiography and quality of life interview with SF–36 questionnaire were performed at the start and after 12 months of the treatment.Results. Long-term therapy lead to achievement of target BP level, improved quality of life and reduced in left ventricular hypertrophy in patients with HTwp. Nebivolol reduced systolic “BP load” more significantly than indapamide did, exerted favorable influence on circadian BP rhythm and reduced heart rate. Monotherapy with nebivolol showed benefits in effect on quality of life.Conclusion. Nebivolol has some advantages in comparison with indapamide and enalapril in antihypertensive therapy of patients with stress-associated HT.

  7. Curved Beam Computed Tomography based Structural Rigidity Analysis of Bones with Simulated Lytic Defect: A Comparative Study with Finite Element Analysis.

    Science.gov (United States)

    Oftadeh, R; Karimi, Z; Villa-Camacho, J; Tanck, E; Verdonschot, N; Goebel, R; Snyder, B D; Hashemi, H N; Vaziri, A; Nazarian, A

    2016-01-01

    In this paper, a CT based structural rigidity analysis (CTRA) method that incorporates bone intrinsic local curvature is introduced to assess the compressive failure load of human femur with simulated lytic defects. The proposed CTRA is based on a three dimensional curved beam theory to obtain critical stresses within the human femur model. To test the proposed method, ten human cadaveric femurs with and without simulated defects were mechanically tested under axial compression to failure. Quantitative computed tomography images were acquired from the samples, and CTRA and finite element analysis were performed to obtain the failure load as well as rigidities in both straight and curved cross sections. Experimental results were compared to the results obtained from FEA and CTRA. The failure loads predicated by curved beam CTRA and FEA are in agreement with experimental results. The results also show that the proposed method is an efficient and reliable method to find both the location and magnitude of failure load. Moreover, the results show that the proposed curved CTRA outperforms the regular straight beam CTRA, which ignores the bone intrinsic curvature and can be used as a useful tool in clinical practices. PMID:27585495

  8. Drugs and lifestyle for the treatment and prevention of coronary artery disease: comparative analysis of the scientific basis

    Directory of Open Access Journals (Sweden)

    P.L. da Luz

    2011-10-01

    Full Text Available In this article, we compare two strategies for atherosclerosis treatment: drugs and healthy lifestyle. Statins are the principal drugs used for the treatment of atherosclerosis. Several secondary prevention studies have demonstrated that statins can significantly reduce cardiovascular events including coronary death, the need for surgical revascularization, stroke, total mortality, as well as fatal and non-fatal myocardial infarction. These results were observed in both men and women, the elderly, smokers and non-smokers, diabetics and hypertensives. Primary prevention studies yielded similar results, although total mortality was not affected. Statins also induce atheroma regression and do not cause cancer. However, many unresolved issues remain, such as partial risk reduction, costs, several potential side effects, and long-term use by young patients. Statins act mainly as lipid-lowering drugs but pleiotropic actions are also present. Healthy lifestyle, on the other hand, is effective and inexpensive and has no harmful effects. Five items are associated with lower cardiac risk: non-smoking, BMI ≤25, regular exercise (30 min/day, healthy diet (fruits, vegetables, low-saturated fat, and 5-30 g alcohol/day. Nevertheless, there are difficulties in implementing these measures both at the individual and population levels. Changes in behavior require multidisciplinary care, including medical, nutritional, and psychological counseling. Participation of the entire society is required for such implementation, i.e., universities, schools, media, government, and medical societies. Although these efforts represent a major challenge, such a task must be faced in order to halt the atherosclerosis epidemic that threatens the world.

  9. Acute arterial occlusion - kidney

    Science.gov (United States)

    ... arterial thrombosis; Renal artery embolism; Acute renal artery occlusion; Embolism - renal artery ... often result in permanent kidney failure. Acute arterial occlusion of the renal artery can occur after injury ...

  10. All-ceramic and porcelain-fused-to-metal fixed partial dentures: a comparative study by 2D finite element analyses

    Directory of Open Access Journals (Sweden)

    Andréa Barreira Motta

    2007-10-01

    Full Text Available All-ceramic fixed partial dentures (FPDs have an esthetic approach for oral rehabilitation. However, metal-ceramic FPDs are best indicated in the posterior area where the follow-up studies found a lower failure rate. This 2D finite element study compared the stress distribution on 3-unit all-ceramic and metal-ceramic FPDs and identified the areas of major risk of failure. Three FPD models were designed: (1 metal-ceramic FPD; (2 All-ceramic FPD with the veneering porcelain on the occlusal and cervical surface of the abutment tooth; (3 All-ceramic FPD with the veneering porcelain only on the occlusal surface. A 100 N load was applied in an area of 0.5 mm² on the working cusps, following these simulations: (1 on the abutment teeth and the pontic; (2 only on the abutment teeth; and (3 only on the pontic. Relative to the maximum stress values found for the physiological load, all-ceramic FPD with only occlusal veneering porcelain produced the lowest stress value (220 MPa, followed by all-ceramic FPD with cervical veneering porcelain (322 MPa and metal-ceramic FPD (387 MPa. The stress distribution of the load applied on the abutments was significantly better compared to the other two load simulations. The highest principal stress values were low and limited in a small area for the three types of models under this load. When the load was applied on the pontic, the highest stress values appeared on the connector areas between the abutments and pontic. In conclusion, the best stress values and distribution were found for the all-ceramic FPD with the veneering porcelain only on the occlusal surface. However, in under clinical conditions, fatigue conditions and restoration defects must be considered.

  11. Comparative measurement of silicon and major elements (P,S,Cl,K,Ca) in arterial walls using macro and microbeam analysis

    International Nuclear Information System (INIS)

    There are few techniques available for the measurement of silicon at trace levels in biological materials. PIXE and prompt nuclear reaction analysis were used to locate and measure silicon and major elements in arterial walls. Macrobeam analysis, carried out by the Van de Graaff accelerator at CENBG, enabled measurement of mean tissue levels. Microbeam analysis, using the nuclear microprobe at Karlsruhe, yielded the distribution of these elements through the thickness of the arterial wall. The microanalyses were performed on arterial walls from healthy rabbits and the macrobeam study was carried out on the same samples and also on human aorta specimens

  12. Sensitivity of 3D gradient recalled echo susceptibility-weighted imaging technique compared to computed tomography angiography for detection of middle cerebral artery thrombus in acute stroke

    Directory of Open Access Journals (Sweden)

    Amit Agarwal

    2014-11-01

    Full Text Available We aimed at comparing the sensitivity of magnetic resonance (MR susceptibility-weighted imaging (SWI with computed tomography angiography (CTA in the detection of middle cerebral artery (MCA thrombus in acute stroke. Seventy-nine patients with acute MCA stroke was selected using our search engine software; only the ones showing restricted diffusion in the MCA territory on diffusion-weighted images were included. We finally selected 35 patients who had done both MRI (including SWI and CTA. Twenty random subjects with completely normal MRI (including SWI exam were selected as control. Two neuroradiologists (blinded to the presence or absence of stroke reviewed the SW images and then compared the findings with CT angiogram (in patients with stroke. The number of MCA segments showing thrombus in each patient was tabulated to estimate the thrombus burden. Thrombus was detected on SWI in one or more MCA segments in 30 out of 35 patients, on the first review. Of the 30, SWI showed thrombus in more than one MCA segments in 7 patients. CTA depicted branch occlusion in 31 cases. Thrombus was seen on both SWI and CTA in 28 patients. Thrombus was noted in two patients on SWI only, with no corresponding abnormality seen on CTA. Two patients with acute MCA showed no vascular occlusion or thrombus on either CTA or SWI. Only two case of false-positive thrombus was reported in normal control subjects. Susceptibility-weighted images had sensitivity and specificity of 86% and 90% respectively, with positive predictive value 94%. Sensitivity was 86% for SWI, compared with 89% for CTA, and this difference was statistically insignificant (P>0.05. Of all the positive cases on CTA (31 corresponding thrombus was seen on SWI in 90% of subjects (28 of 31. Susceptibility-weighted imaging has high sensitivity for detection of thrombus in acute MCA stroke. Moreover, SWI is a powerful technique for estimation of thrombus burden, which can be challenging on CTA.

  13. Evaluation of sorafenib treatment and hepatic arterial infusion chemotherapy for advanced hepatocellular carcinoma: a comparative study using the propensity score matching method

    International Nuclear Information System (INIS)

    While sorafenib (SFN) is the established worldwide standard therapeutic agent for advanced hepatocellular carcinoma (HCC), hepatic arterial infusion chemotherapy (HAIC) is also considered a favorable treatment for some advanced HCCs. This study aimed to evaluate each treatment and provide an optimal therapeutic choice for advanced HCCs. We analyzed 72 patients treated with SFN and 128 patients receiving HAIC. Both treatment groups were analyzed for prognostic and disease progression factors, and matched pair analysis was performed using the propensity score matching method. The preferable status of intrahepatic lesions, that is, no lesions or only a single (<3 cm) intrahepetic lesion, was positively associated with good prognosis and negatively associated with disease progression in the SFN group. Maximum tumor size (>5 cm) and low albumin (≤3.4 g/dL) were poor prognostic and disease progression factors in the HAIC group. Analysis of 53 patients selected from each of the SFN and HAIC groups based on the propensity score matching method showed no significant differences in survival or disease progression between the two matched subgroups. On the other hand, progression-free survival (PFS) in the HAIC-matched subgroup was significantly longer than in the SFN-matched subgroup, particularly in patients with portal vein invasion (PVI) and/or without extrahepatic spread (EHS). The treatment efficacy of HAIC is similar to that of SFN regarding survival and disease progression. Longer PFS might be expected for HAIC compared with SFN, particularly in patients with PVI and/or without EHS

  14. A comparative study of PGI2 mimetics used clinically on the vasorelaxation of human pulmonary arteries and veins, role of the DP-receptor.

    Science.gov (United States)

    Benyahia, Chabha; Boukais, Kamel; Gomez, Ingrid; Silverstein, Adam; Clapp, Lucie; Fabre, Aurélie; Danel, Claire; Leséche, Guy; Longrois, Dan; Norel, Xavier

    2013-12-01

    Prostacyclin (PGI2) and its mimetics (iloprost, treprostinil, beraprost and MRE-269) are potent vasodilators (via IP-receptor activation) and a major therapeutic intervention for pulmonary hypertension (PH). These PGI2 mimetics have anti-proliferative and potent vasodilator effects on pulmonary vessels. We compared the relaxant effects induced by these recognized IP-agonists in isolated human pulmonary arteries (HPA) and veins (HPV). In addition, using selective antagonists, the possible activation of other prostanoid relaxant receptors (DP, EP4) was investigated. Iloprost and treprostinil were the more potent relaxant agonists when both vessels were analyzed. HPA were significantly more sensitive to iloprost than to treprostinil, pEC50 values: 7.94±0.06 (n=23) and 6.73±0.08 (n=33), respectively. In contrast, in HPV these agonists were equipotent. The relaxations induced by treprostinil were completely or partially inhibited by IP-antagonists in HPA or HPV, respectively. The effects of the IP-agonists were not significantly modified by the EP4 antagonist. Finally, DP-antagonists inhibited the relaxations induced by treprostinil in HPV, suggesting that the DP-receptor plays a role in treprostinil-induced relaxation in the HPV. These data suggest that iloprost and treprostinil should be the most effective clinically available agonists to decrease pulmonary vascular resistance and to prevent oedema formation (by similar decrease in HPA and HPV resistance) in PH patients. PMID:23850788

  15. Experimental Embolization of Rabbit Renal Arteries to Compare the Effects of Poly L-Lactic Acid Microspheres With and Without Epirubicin Release Against Intraarterial Injection of Epirubicin

    International Nuclear Information System (INIS)

    Purpose: We performed a basic investigation using white rabbits of the sustained release and embolizing effects of poly L-lactic acid microspheres (PLA) to determine their usefulness for chemoembolization.Methods: Fifteen male Japanese white rabbits were used. Sustained release of an embolizing material, EPI-PLA was accomplished with 1 mg of PLA containing 0.03 mg of epirubicin hydrochloride (EPI). Embolization with 50 mg of PLA (total dose of EPI 1.5 mg) was performed after the renal artery of the rabbits was selected (Chemo-TAE group). A group in which a bolus of 1.5 mg EPI alone was injected through the renal artery (TAI group) was established as a control group. Furthermore, a group in which embolization was performed with 50 mg of PLA alone (TAE group) was also established. These three groups, each consisting of five rabbits, were compared.Results: Blood EPI levels were serially measured. The blood EPI level in the TAI group rapidly reached a peak more than 30 min after injection, then decreased to almost zero 24 hr after injection. In the Chemo-TAE group, the blood EPI level was transiently increased 30 min after embolization, but remained low thereafter until 24 hr after embolization. EPI levels in kidney tissue isolated 24 hr after embolization were measured. In the Chemo-TAE group, the tissue EPI level was significantly higher than that in the TAI group. When isolated kidneys were macroscopically and histologically examined, atrophy of the entire embolized kidney, as well as infarction and necrosis in the renal cortex, were observed in both the TAE group and the Chemo-TAE group. However, there were no such findings in the TAI group. The area of the infarction in the renal cortex did not significantly differ between the Chemo-TAE group and the TAE group; however, there was vascular injury in the Chemo-TAE group and none in the TAE group.Conclusion: It was demonstrated that EPI-PLA, a chemoembolizing material, maintained high local concentrations of the

  16. Experimental embolization of rabbit renal arteries to compare the effects of poly L-lactic acid microspheres with and without epirubicin release against ntraarterial injection of epirubicin

    International Nuclear Information System (INIS)

    Purpose: We performed a basic investigation using white rabbits of the sustained release and embolizing effects of poly L-lactic acid microspheres (PLA) to determine their usefulness for chemoembolization.Methods: Fifteen male Japanese white rabbits were used. Sustained release of an embolizing material, EPI-PLA was accomplished with l m g of PLA containing 0.03 mg of epirubicin hydrochloride (EPI). Embolization with 50 mg of PLA (total dose of EPI l.5 mg) was performed after the renal artery of the rabbits was selected (Chemo-TAE group). A group in which a bolus of 1.5 mg EPI alone was injected through the renal artery (TAI group) was established as a control group. Furthermore, a group in which embolization was performed with 50 mg of PLA alone (TAE group) was also established. These three groups, each consisting of five rabbits, were compared.Results: Blood EPI levels were serially measured. The blood EPI level in the TAI group rapidly reached a peak more than 30 min after injection, then decreased to almost zero 24 hr after injection. In the Chemo-TAE group, the blood EPI level was transiently increased 30 min after embolization, but remained low thereafter until 24 hr after embolization. EPI levels in kidney tissue isolated 24 hr after embolization were measured. In the Chemo-TAE group, the tissue EPI level was significantly higher than that in the TAI group. When isolated kidneys were macroscopically and histologically examined, atrophy of the entire embolized kidney, as well as infarction and necrosis in the renal cortex, were observed in both the TAE group and the Chemo-TAE group. However, there were no such findings in the TAI group. The area of the infarction in the renal cortex did not significantly differ between the Chemo-TAE group and the TAE group; however, there was vascular injury in the Chemo-TAE group and none in the TAE group.Conclusion: It was demonstrated that EPI-PLA, a chemo-embolizing material, maintained high local concentrations of the

  17. Finite Earth

    Science.gov (United States)

    2015-10-01

    The world has agreed on 17 Sustainable Development Goals, to be adopted this week. This is great progress towards acknowledging that the planet's finite resources need to be managed carefully in the face of humanity's unlimited aspirations.

  18. Quantitative and qualitative assessment of non-obstructive left main coronary artery plaques using 64-multislice computed tomography compared with intravascular ultrasound

    Institute of Scientific and Technical Information of China (English)

    SHEN Yi; QIAN Ju-ying; WANG Ming-hui; LIU Yuan; LIU Xue-bo; GE Lei; MA Jian-ying; GE Jun-bo

    2010-01-01

    Background There are few reports of quantitative and qualitative measuring of left main coronary artery (LMCA) plaques by multislice computed tomography coronary angiography (MSCTA), especially when compared with intravascular ultrasound (IVUS) as reference standard. The aim of this study was to evaluate the use of 64-MSCTA in the diagnosis of LMCA disease, and the accuracy of MSCTA in the quantitative and qualitative assessment of the LMCA lesion as compared with IVUS.Methods A total of 91 patients (53 men, 38 women, mean age (64.78±9.19) years) were examined by 64-MSCTA and IVUS. Compared with the IVUS, the sensitivity, specificity, positive and negative predictive values (PPV and NPV) of the MSCTA on the diagnosis of LMCA diseases were calculated. Also, kappa index (K) for the agreement between MSCTA and IVUS was calculated. Minimal lumen area (MLA), external elastic membrane cross-sectional area (EEM-CSA) and plaque burden were measured by two blinded and independent operators on MSCTA cross-sectional reconstruction and compared with the parameters measured from IVUS by manually tracing. The CT value of soft, fibrous and calcific plaques was measured using IVUS classification of the plaques.Results The sensitivity, specificity, PPV and NPV of MSCTA for detecting LMCA plaques were 93.1%, 84.2%, 95.7%, 76.2%, respectively. Kappa index (K=0.744, P<0.001) indicated excellent agreement between MSCTA and IVUS. The Pearson index between MLA on IVUS and MLA on MSCTA was 0.815 (P <0.01). The Pearson index of plaque burden and EEM-CSA between IVUS and MSCTA was 0.736 and 0.740 respectively (both P <0.01). The CT value of soft plaque, fibrous plaque and calcific plaque compared with IVUS were (52.52±15.71) HU, (108.32±43.44) HU and (604.16±377.67) HU (P<0.001). Receiver operating characteristic curve analysis of CT value of non-calcific plaques for predicting soft plaques showed the cutpoint was 54.35 HU, with a sensitivity of 83.3% and specificity of 94

  19. Short term non-invasive ventilation post-surgery improves arterial blood-gases in obese subjects compared to supplemental oxygen delivery - a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Zoremba Norbert

    2011-05-01

    Full Text Available Abstract Background In the immediate postoperative period, obese patients are more likely to exhibit hypoxaemia due to atelectasis and impaired respiratory mechanics, changes which can be attenuated by non-invasive ventilation (NIV. The aim of the study was to evaluate the duration of any effects of early initiation of short term pressure support NIV vs. traditional oxygen delivery via venturi mask in obese patients during their stay in the PACU. Methods After ethics committee approval and informed consent, we prospectively studied 60 obese patients (BMI 30-45 undergoing minor peripheral surgery. Half were randomly assigned to receive short term NIV during their PACU stay, while the others received routine treatment (supplemental oxygen via venturi mask. Premedication, general anaesthesia and respiratory settings were standardized. We measured arterial oxygen saturation by pulse oximetry and blood gas analysis on air breathing. Inspiratory and expiratory lung function was measured preoperatively (baseline and at 10 min, 1 h, 2 h, 6 h and 24 h after extubation, with the patient supine, in a 30 degrees head-up position. The two groups were compared using repeated-measure analysis of variance (ANOVA and t-test analysis. Statistical significance was considered to be P Results There were no differences at the first assessment. During the PACU stay, pulmonary function in the NIV group was significantly better than in the controls (p Conclusion Early initiation of short term NIV during in the PACU promotes more rapid recovery of postoperative lung function and oxygenation in the obese. The effect lasted 24 hours after discontinuation of NIV. Patient selection is necessary in order to establish clinically relevant improvements. Trial Registration# DRKS00000751; http://www.germanctr.de

  20. Numerical Simulation of Coronary Artery Bypass Graft with an Assistant Graft

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; WANG Feng

    2014-01-01

    The conventional bypass design is to implant a graft on the stenosed host artery allowing blood to flow bypass the stenotic artery. However, restenosis is a challenging problem which finally results in reoperation. The purpose of this paper is to propose a new bypass graft design of coronary artery with an assistant graft for the treatment of coronary artery stenosis. An additional assistant graft was employed in the new design compared with the conventional ETS anastomosis. Numerical simulations were performed by means of finite volume method using computational fluid dynamics (CFD) solver. Results demonstrated that the new anastomoses model provided a more smooth flow at the distal ETS anastomosis without any stagnation point on anastomotic bed and vortex formation in the heel region. Oscillatory shear index (OSI) and time-averaged wall shear stress gradient (TAWSSG) at the artery bed of the distal ETS anastomosis were reduced. The coronary artery bypass graft with an assistant graft is feasible to improve the local hemodynamics and diminish the probability of restenosis in the treatment of coronary artery stenosis.

  1. A comparative study on inhibition of total astragalus saponins and astragaloside IV on TNFR1-mediated signaling pathways in arterial endothelial cells.

    Directory of Open Access Journals (Sweden)

    Qin-she Liu

    Full Text Available BACKGROUND: Both total astragalus saponins (AST and it's main component astragaloside IV (ASIV have been used in China as cardiovascular protective medicines. However, the anti-inflammatory activities that are beneficial for cardiovascular health have never been compared directly and the molecular mechanisms remain unresolved. This study was conducted to compare the inhibitory effects of these drugs on TNFα-induced cell responses, related signaling pathways, and the underlying mechanisms in mouse arterial endothelial cells. METHODOLOGY/PRINCIPAL FINDINGS: Real-time qRT-PCR was performed to determine the expression of cell adhesion molecule (CAM genes. Immunofluorescent staining was used to detect the nuclear translocation of transcription factor NF-κB-p65. Western Blot analysis was used to identify TNFα-induced NF-κB-p65 phosphorylation, IκBα degradation, and caspase-3 cleavage. Cell surface proteins were isolated and TNFα receptor-1(TNFR1 expression was determined. The results suggest that both AST and ASIV attenuate TNFα-induced up-regulation of CAMs mRNA and upstream nuclear translocation and phosphorylation of NF-κB-p65. However, TNFR1-mediated IκBα degradation, cleavage of caspase-3 and apoptosis were inhibited only by AST. These differences in the actions of AST and ASIV could be explained by the presence of other components in AST, such as ASII and ASIII, which also had an inhibitory effect on TNFR1-induced IκBα degradation. Moreover, AST, but not ASIV, was able to reduce TNFR1 protein level on the cell surface. Furthermore, mechanistic investigation demonstrated that TNFR1-mediated IκBα degradation was reversed by the use of TAPI-0, an inhibitor of TNFα converting enzyme (TACE, suggesting the involvement of TACE in the modulation of surface TNFR1 level by AST. CONCLUSION: ASIV was not a better inhibitor than AST, at least on the inhibition of TNFα-induced inflammatory responses and TNFR1-mediated signaling pathways in

  2. Ex Vivo and in Silico Study of Human Common Carotid Arteries Pressure Response in Physiological and Inverted State

    Science.gov (United States)

    Piechna, A.; Cieślicki, K.; Lombarski, L.; Ciszek, B.

    2015-02-01

    Arterial walls are a multilayer structures with nonlinear material characteristics. Furthermore, residual stresses exist in unloaded state (zero-pressure condition) and they affect arterial behavior. To investigate these phenomena a number of theoretical and numerical studies were performed, however no experimental validation was proposed and realized yet. We cannot get rid of residual stresses without damaging the arterial segment. In this paper we propose a novel experiment to validate a numerical model of artery with residual stresses. The inspiration for our study originates from experiments made by Dobrin on dogs' arteries (1999). We applied the idea of turning the artery inside out. After such an operation the sequence of layer is reversed and the residual stresses are re-ordered. We performed several pressure-inflation tests on human Common Carotid Arteries (CCA) in normal and inverted configurations. The nonlinear responses of arterial behavior were obtained and compared to the numerical model. Computer simulations were carried out using the commercial software which applied the finite element method (FEM). Then, these results were discussed.

  3. Patient Satisfaction After Femoral Arterial Access Site Closure Using the ExoSeal{sup ®} Vascular Closure Device Compared to Manual Compression: A Prospective Intra-individual Comparative Study

    Energy Technology Data Exchange (ETDEWEB)

    Pieper, Claus Christian, E-mail: claus.christian.pieper@ukb.uni-bonn.de; Thomas, Daniel, E-mail: daniel.thomas@ukb.uni-bonn.de [University of Bonn, Department of Radiology (Germany); Nadal, Jennifer, E-mail: jennifer.nadal@ukb.uni-bonn.de [University of Bonn, Institute for Medical Biometry, Informatics and Epidemiology (Germany); Willinek, Winfried A., E-mail: w.willinek@bk-trier.de; Schild, Hans Heinz, E-mail: hans.schild@ukb.uni-bonn.de; Meyer, Carsten, E-mail: carsten.meyer@ukb.uni-bonn.de [University of Bonn, Department of Radiology (Germany)

    2016-01-15

    PurposeTo intra-individually compare discomfort levels and patient satisfaction after arterial access closure using the ExoSeal{sup ®} vascular closure device (VCD) and manual compression (MC) in a prospective study design.MethodsPatients undergoing two planned interventions from 07/2013 to 09/2014 could participate in the study. Access closure was performed with an ExoSeal{sup ®}-VCD in one and MC in the other intervention. Patients were clinically and sonographically examined and were given questionnaires 1 day after intervention [groin- and back-pain during bedrest (100-point visual analog scale; 0: no pain); comfortability of bedrest (10-point Likert scale, 1: comfortable), satisfaction with closure (10-point Likert scale, 1: very satisfied)]. Results were analyzed in a cross-over design.Results48 patients (29 male, median age 62.5 (32–88) years) were included. An ExoSeal{sup ®}-VCD was used first in 25 cases. As four of these subsequently refused MC as second intervention, data from 44 patients could be analyzed. All closures were technically successful (successful device deployment) without major complications. Groin- and back-pain after VCD-use/MC was 0 (0–15) vs. 10 (0–80) and 0 (0–75) vs. 25 (0–90), respectively (p < 0.0001). Bedrest after VCD-use was more comfortable than after MC [1 (range 1–7) vs. 6 (2–10); p < 0.0001]. Satisfaction with the closure procedure and with the intervention in general was higher after VCD-use compared to MC [1 (1–3) vs. 5 (2–10) and 1 (1–2) vs. 2 (1–4), respectively; p < 0.0001].ConclusionIntra-individual comparison showed pain levels and discomfort to be significantly lower after ExoSeal{sup ®} use compared to MC. VCD closure was associated with higher satisfaction both with the closure itself and with the intervention in general.

  4. Carotid artery stenting

    International Nuclear Information System (INIS)

    An ipsilateral stenosis of the internal carotid artery is found in 10 - 15 % of all ischemic strokes and indicates an increased risk of a second stroke. Carotid artery stenting (CAS) is a therapy that is established for many years. CAS reveals complication rates and long-term efficacy comparable to carotid endarterectomy (TEA). Especially younger patients seem to benefit from CAS. Abilities and experiences of the therapist and the choice of the techniques used are critical for patient safety. The efficacy of CAS for treatment of asymptomatic carotid stenosis is probable but still unproven in prospective-randomized trial. (orig.)

  5. Carotid artery stenting; Karotisangioplastie

    Energy Technology Data Exchange (ETDEWEB)

    Fiehler, Jens [Universitaetsklinikum Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Neuroradiologische Diagnostik und Intervention, Diagnostikzentrum

    2009-09-15

    An ipsilateral stenosis of the internal carotid artery is found in 10 - 15 % of all ischemic strokes and indicates an increased risk of a second stroke. Carotid artery stenting (CAS) is a therapy that is established for many years. CAS reveals complication rates and long-term efficacy comparable to carotid endarterectomy (TEA). Especially younger patients seem to benefit from CAS. Abilities and experiences of the therapist and the choice of the techniques used are critical for patient safety. The efficacy of CAS for treatment of asymptomatic carotid stenosis is probable but still unproven in prospective-randomized trial. (orig.)

  6. Diagnóstico clínico diferencial entre oclusão da artéria carótida interna e da artéria cerebral média A comparative symptomatological study of internal carotid artery occlusion and middle cerebral artery occlusion

    Directory of Open Access Journals (Sweden)

    Roberto Melaragno

    1971-03-01

    Full Text Available Foi feito um estudo comparativo entre o quadro clínico inicial de 61 casos de oclusão da artéria carótida interna e o de 23 casos de oclusão da artéria cerebral média, diagnosticados pela angiografia cerebral e/ou pela necropsia em pacientes submetidos ou não à cirurgia vascular. Os autores comparam a idade dos pacientes, o sexo, o modo de início da afecção, a existência ou não de convulsões e/ou cefaléias, a ocorrência do acidente cerebral durante o sono ou em vigília, a existência de ictos prévios, os níveis de pressão arterial, o grau de consciência, a força muscular, os achados eletrencefalográficos, a palpação e ausculta das carótidas em nível cervical. Os resultados são demonstrados em índices percentuais, pelos quais os autores inferem que não há significância estatística nesses elementos com três exceções: a maior ocorrência de convulsões nas oclusões da artéria cerebral média em relação às da carótida, a oftalmodinamometria e a sintomatologia carotídea cervical. A oftalmodinamometria revela valores significantemente menores nas pressões da artéria central da retina, no mesmo lado da trombose da carótida em 70,0% dos casos, enquanto que medidas normais e simétricas verificaram-se em todos os casos de oclusão da artéria cerebral média em que o exame foi realizado. No que concerne a sinais arteriais no pescoço, havia anormalidades palpatórias e auscultatórias em 52,4% dos pacientes com trombose da carótida e em 8,6% dos casos com oclusão da cerebral média. Concluem os autores, portanto, que apenas a angiografia cerebral permite um diagnóstico seguro entre ambas as sedes da oclusão.A comparative study of the early clinical picture in 61 cases of internal carotid artery occlusion and 23 cases of middle cerebral artery occlusion, diagnosed by cerebral angiography and/or necropsy in patients who were either submitted to surgery or not operated upon is reported. The authors had

  7. Carotid Artery Screening

    Science.gov (United States)

    ... Resources Professions Site Index A-Z Carotid Artery Screening What is carotid artery screening? Who should consider ... about carotid artery screening? What is carotid artery screening? Screening examinations are tests performed to find disease ...

  8. Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M., E-mail: sehgalc@uphs.upenn.edu [Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Reamer, Courtney B.; Mohler, Emile R. [Department of Medicine, Division of Cardiovascular Medicine, Section of Vascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2014-02-15

    Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

  9. Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

    International Nuclear Information System (INIS)

    Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging

  10. Chronoecological health watch of arterial stiffness and neuro-cardio-pulmonary function in elderly community at high altitude (3524 m), compared with Japanese town

    OpenAIRE

    Otsuka, K.; Norboo, T.; Y. Otsuka; Higuchi, H; Hayajiri, M.; Narushima, C.; Y. Sato; Tsugoshi, T.; Murakami, S.; Wada, T.; Ishine, M.; Okumiya, K.; Matsubayashi, K.; S. Yano; Chogyal, T.

    2005-01-01

    Effects of high altitude on arterial stiffness and neuro-cardio-pulmonary function were studied. Blood pressure (BP) and heart rate (HR) were measured in a sitting position on resting Ladakhis, living at an altitude of 3250–4647 m (Phey village, 3250 m: 17 men and 55 women; Chumathang village, 4193 m: 29 men and 47 women; Sumdo village, 4540 m: 38 men and 57 women; and Korzok village, 4647 m: 84 men and 70 women). The neuro-cardio-pulmonary function, including the Kohs block design test, the ...

  11. Association between internal carotid artery dissection and arterial tortuosity

    Energy Technology Data Exchange (ETDEWEB)

    Saba, Luca; Piga, Mario [Azienda Ospedaliero Universitaria (A.O.U.), Department of Radiology, Monserrato, Cagliari (Italy); Argiolas, Giovanni Maria; Siotto, Paolo [Azienda Ospedaliero Brotzu (A.O.B.), Department of Radiology, di Cagliari (Italy); Sumer, Suna; Wintermark, Max [Neuroradiology Division, Neuroradiology, UVA Department of Radiology, Charlottesville, VA (United States); Raz, Eytan [New York University School of Medicine, Department of Radiology, New York, NY (United States); Sapienza University of Rome, Department of Neurology and Psychiatry, Rome (Italy); Sanfilippo, Roberto; Montisci, Roberto [Azienda Ospedaliero Universitaria (A.O.U.), Department of Vascular Surgery, di Cagliari (Italy)

    2014-10-18

    Carotid artery dissection is an important cause of ischemic stroke in all age groups, particularly in young patients. The purpose of this work was to assess whether there is an association between the presence of an internal carotid artery dissection (ICAD) and the arterial tortuosity. This study considered 124 patients (72 males and 52 females; median age 57 years) with CT/MR diagnosis of ICAD of the internal carotid artery were considered in this multi-centric retrospective study. The arterial tortuosity was evaluated and, when present, was categorized as elongation, kinking, or coiling. For each patient, both the right and left sides were considered for a total number of 248 arteries in order to have the same number of cases and controls. Fisher's exact test was applied to test the association between elongation, kinking, coiling, dissection, and the side affected by CAD. Fisher's exact test showed a statistically significant association between the ICAD and kinking (p = 0.0089) and coiling (p = 0.0251) whereas no statistically significant difference was found with arterial vessel elongation (p = 0.444). ICAD was more often seen on the left side compared to the right (p = 0.0001). These results were confirmed using both carotid arteries of the same patient as dependent parameter with p = 0.0012, 0.0129, and 0.3323 for kinking, coiling, and elongation, respectively. The presence of kinking and coiling is associated with ICAD. (orig.)

  12. Distribuição comparativa dos glicosaminoglicanos em artérias e veias de diferentes mamíferos Comparative distribution of glycosaminoglycans in arteries and veins of different mammals

    Directory of Open Access Journals (Sweden)

    Mônica V. MARQUEZINI

    1999-10-01

    Full Text Available Foi realizada análise comparativa sobre a distribuição dos glicosaminoglicanos de artérias e veias em ratos, cachorros e humanos. Os nossos resultados demonstraram que dermatam sulfato foi o principal glicosaminoglicano encontrado tanto para as artérias quanto para as veias estudadas. Entretanto, a proporção de dermatam sulfato foi maior nas veias do que nas artérias nas três espécies analisadas. Este aumento pode estar associado às diferenças estruturais e funcionais encontradas na parede destes dois tipos de vasos sangüíneos (nas veias a pressão sangüínea é significativamente mais baixa. Além disso, a quantidade total dos glicosaminoglicanos foi maior nas artérias do que nas veias, sendo as maiores concentrações encontradas nas aortas independentemente da espécie animal estudada. Estes achados abrem perspectiva para o melhor conhecimento das alterações das macromoléculas que possam estar relacionadas ao processo degenerativo vascular, especialmente nas transformações estruturais que as veias safenas sofrem, quando empregadas como enxertos na revascularização do miocárdio.A comparative analysis of the glycosaminoglycan distribution in arteries and veins of humans, rats and dogs was realized. The results showed that the glycosaminoglycan distribution of the arteries was similar to that of venous tissues, where dermatan sulfate was the main glycosaminoglycan found. However, the proportion of dermatan sulfate is significantly greater in venous than in arterial tissues, in the three species. The total amount of the glycosaminoglycans was significantly higher in arteries than in veins, and the highest contents were found in the aortas. These increases may be associated with structural differences of the wall of these two types of blood vessels walls. The blood pressure is significantly lower in venous tissues and veins may exhibit less compressibility than arterial. These findings open perspectives for a better

  13. [COMPARATIVE CEREBROPROTECTIVE EFFECT OF PREVENTIVE ADMINISTRATION OF MAGNESIUM HYDROXYBUTYRATE VERSUS MAGNESIUM SULFATE AND CAVINTON IN RATS WITH COMMON CAROTID ARTERY OCCLUSION].

    Science.gov (United States)

    Tyurenkov, I N; Litvinov, A A; Kurkin, D V; Volotova, E V; Darmanyan, A P; Ozerov, A A

    2016-01-01

    Dose-dependent cerebroprotective effect of magnesium hydroxybutyrate (MHB) on common carotid artery occlusion model in rats was established. Administration of 150 mg/kg MHB led to significant decrease in animal mortality (up to 9.3 times) in comparison to control (p McGraw scale in comparison to control and magnesium sulfate (50% and 20%, respectively). The MHB treated animals also showed improved locomotor and exploratory performance in the open-field test and retained memory performance in the passive avoidance test and extrapolation escape task test. The administration of 150 mg/kg MHB produced three-fold (p < 0.05) decrease of brain edema in animals with cerebral blood flow impairment in comparison to animals treated with magnesium sulfate and cavinton. PMID:27455571

  14. Evaluation of renal artery stenosis using color Doppler sonography in young patients with multiple renal arteries

    Institute of Scientific and Technical Information of China (English)

    QIN Wei; ZHANG Xin; YANG Min; ZHONG Xu-hui; ZHAO Ming-hui

    2011-01-01

    Background Some individuals have multiple renal arteries. Severe stenosis in one of the arteries may cause refractory hypertension. The detection of stenosis within one of the multiple renal arteries usually required invasive procedures, such as computed tomographic angiography (CTA) and magnetic resonance angiography (MRA). This study reported the application of color Doppler sonography (CDS) in the detection of severe stenosis in one of the multiple arteries.Methods Patients with multiple renal arteries and one of the arteries with severe stenosis were retrospectively studied. Peak systolic velocities (PSV) of renal arteries and the intrarenal CDS patterns were collected and compared. The diagnosis was confirmed by digital subtraction angiography (DSA).Results Four children with multiple renal arteries and one of the arteries with stenosis were investigated. They were admitted due to refractory hypertension. CDS screening identified two renal arteries in one kidney of each patient with one of the two renal arteries having stenosis >70%. The PSV of the stenosed arteries were much higher, and the intrarenal CDS patterns supplied by the stenosed arteries changed into T-P patterns.Conclusion Non-invasive CDS technology may be a useful method to identify severe stenosis in one of multiple renal arteries in young patients.

  15. Accurate Finite Difference Algorithms

    Science.gov (United States)

    Goodrich, John W.

    1996-01-01

    Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

  16. Percutaneous coronary intervention versus coronary-artery bypass grafting for severe coronary artery disease

    OpenAIRE

    Serruys, Patrick; Morice, Marie-Claude; Kappetein, Arie Pieter; Colombo, Antonio; Holmes, David; Mack, Michael; Stahle, E.; Feldman, Ted; Brand, Marcel, van den; Bass, Eric; Dyck, Nic; Leadly, Katrin; Dawkins, Keith; Mohr, Friedrich

    2009-01-01

    textabstractBACKGROUND Percutaneous coronary intervention (PCI) involving drug-eluting stents is increasingly used to treat complex coronary artery disease, although coronary-artery bypass grafting (CABG) has been the treatment of choice historically. Our trial compared PCI and CABG for treating patients with previously untreated three-vessel or left main coronary artery disease (or both). METHODS We randomly assigned 1800 patients with three-vessel or left main coronary artery disease to und...

  17. $\\delta$-Expansion at Finite Temperature

    OpenAIRE

    Ramos, Rudnei O.

    1996-01-01

    We apply the $\\delta$-expansion perturbation scheme to the $\\lambda \\phi^{4}$ self-interacting scalar field theory in 3+1 D at finite temperature. In the $\\delta$-expansion the interaction term is written as $\\lambda (\\phi^{2})^{ 1 + \\delta}$ and $\\delta$ is considered as the perturbation parameter. We compute within this perturbative approach the renormalized mass at finite temperature at a finite order in $\\delta$. The results are compared with the usual loop-expansion at finite temperature.

  18. A STUDY ON THE PATTERNS OF CIRCUMFLEX FEMORAL ARTERIES

    Directory of Open Access Journals (Sweden)

    R. Chitra

    2015-09-01

    Full Text Available Context: Many different patterns have been described to classify the origins of circumflex femoral arteries by many authors since from 1860.The aim of the present study was to classify the circumflex femoral arteries in 100 lower limbs of adult cadavers of both sexes following the recent classification and to compare with the previous studies. Materials and Methods: A total of 100 lower limbs of 50 embalmed human adult cadavers (Male: 37, Female: 13 were dissected and observed for the origins of circumflex femoral arteries in femoral triangle in routine educational dissection in the period of 2005-2009 Results: The medial and lateral circumflex femoral arteries have been classified into three different patterns based on the levels of their origin. Pattern I: Both arteries arose from the profunda femoris artery (56%. Type Ia, medial circumflex femoral artery origin was proximal to the lateral circumflex femoral artery origin (69%; Type Ib, lateral circumflex femoral artery origin was proximal to medial circumflex femoral artery origin (16 %; Type Ic, both arteries arose from a common trunk or at same level (14%. Pattern II: One of the arteries arose from the femoral artery and the other from the profunda femoris artery (36%. Type IIa, the medial circumflex femoral artery arose from the femoral artery (75% and Type IIb, the lateral circumflex femoral artery arose from the femoral artery (25%.Pattern III: Both arteries arose from the femoral artery (7%. The medial circumflex femoral artery was absent in a female cadaver on right side. Conclusion: In every pattern or type, there was significantly unilateral higher occurrence than bilateral occurrence. A precise knowledge of the circumflex femoral arteries in relation to the profunda femoris artery is important in surgical interventions of the hip region

  19. Locally Finite Root Supersystems

    OpenAIRE

    YOUSOFZADEH, Malihe

    2013-01-01

    We introduce the notion of locally finite root supersystems as a generalization of both locally finite root systems and generalized root systems. We classify irreducible locally finite root supersystems.

  20. Evaluation of contrast-enhanced magnetic resonance angiography (MRA) using Gd-DOTA compared with time-of-flight MRA in the diagnosis of clinically significant non-coronary arterial disease

    International Nuclear Information System (INIS)

    This trial assessed diagnostic accuracy of contrast-enhanced magnetic resonance angiography (MRA) with meglumine gadoterate (Gd-DOTA) at 3 Tesla (T) over unenhanced MRA at 3 T in non-coronary arterial diseases by comparing their accuracy with that of the gold standard, x-ray angiography. Ninety-two patients with suspected non-coronary arterial disease underwent in fixed sequence unenhanced time-of flight (TOF) MRA, contrast-enhanced MRA using a Gd-DOTA bolus (intravenous bolus 0.1 mmol/kg) and x-ray angiography. Eighty-four patients (71 male, 13 female; median age 64.5 years) were included in an intent-to-treat efficacy analysis. Targeted vascular areas were aorto-iliac, calf, carotid, femoral, popliteal and renal. Within-patient accuracy was significantly higher with contrast-enhanced MRA using Gd-DOTA than with unenhanced MRA (p = 0.0003). There was 84.4 ± 17.5% agreement between contrast-enhanced MRA (Gd-DOTA) and x-ray angiography, compared with 76.8 ± 20.4% between non-enhanced MRA and x-ray angiography. Sensitivity and specificity were also better with Gd-DOTA compared with non-enhanced MRA at the segment level. Duration of the MRA procedure was 3.5 times shorter with Gd-DOTA compared with non-enhanced MRA. Six patients reported six mild or moderate adverse events. No serious adverse events occurred. Contrast-enhanced MRA using Gd-DOTA at 3 T was superior to unenhanced TOF MRA in the vascular territories investigated. (orig.)

  1. Carotid Artery Disease

    Science.gov (United States)

    ... brain with blood. If you have carotid artery disease, the arteries become narrow, usually because of atherosclerosis. ... one of the causes of stroke. Carotid artery disease often does not cause symptoms, but there are ...

  2. Mesenteric artery ischemia

    Science.gov (United States)

    Mesenteric artery ischemia occurs when there is a narrowing or blockage of one or more of the three major arteries that ... that supply blood to the intestine causes mesenteric ischemia. The arteries that supply blood to the intestines ...

  3. Astrocytic tumour grading: a comparative study of three-dimensional pseudocontinuous arterial spin labelling, dynamic susceptibility contrast-enhanced perfusion-weighted imaging, and diffusion-weighted imaging

    International Nuclear Information System (INIS)

    We hypothesized that three-dimensional pseudocontinuous arterial spin labelling (pCASL) may have similar efficacy in astrocytic tumour grading as dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI), and the grading accuracy may be further improved when combined with apparent diffusion coefficient (ADC) values. Forty-three patients with astrocytic tumours were studied using diffusion weighted imaging (DWI), pCASL, and DSC-PWI. Histograms of ADC and normalized tumour cerebral blood flow values (nCBF on pCASL and nrCBF on DSC-PWI) were measured and analyzed. The mean 10 % ADC value was the DWI parameter that provided the best differentiation between low-grade astrocytoma (LGA) and high-grade astrocytoma (HGA). The nCBF and nrCBF (1.810 ± 0.979 and 2.070 ± 1.048) in LGA were significantly lower than those (4.505 ± 2.270 and 5.922 ± 2.630) in HGA. For differentiation between LGA and HGA, the cutoff values of 0.764 x 10-3 mm2/s for mean 10 % ADC, 2.374 for nCBF, and 3.464 for nrCBF provided the optimal accuracy (74.4 %, 86.1 %, and 88.6 %, respectively). Combining the ADC values with nCBF or nrCBF could further improve the grading accuracy to 97.7 % or 95.3 %, respectively. pCASL is an alternative to DSC-PWI for astrocytic tumour grading. The combination of DWI and contrast-free pCASL offers a valuable choice in patients with risk factors. (orig.)

  4. Astrocytic tumour grading: a comparative study of three-dimensional pseudocontinuous arterial spin labelling, dynamic susceptibility contrast-enhanced perfusion-weighted imaging, and diffusion-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Hua-Feng [302 Hospital of Chinese People' s Liberation Army, Department of Radiology, Beijing (China); Chen, Zhi-Ye; Wang, Yu-Lin; Wang, Yan; Ma, Lin [People' s Liberation Army General Hospital, Department of Radiology, Beijing (China); Lou, Xin [People' s Liberation Army General Hospital, Department of Radiology, Beijing (China); University of California, Department of Neurology, Los Angeles, CA (United States); Gui, Qiu-Ping [People' s Liberation Army General Hospital, Department of Pathology, Beijing (China); Shi, Kai-Ning; Zhou, Zhen-Yu; Zheng, Dan-Dan [General Electric Healthcare (China) Co., Ltd., Beijing; Wang, Danny J.J. [University of California, Department of Neurology, Los Angeles, CA (United States)

    2015-12-15

    We hypothesized that three-dimensional pseudocontinuous arterial spin labelling (pCASL) may have similar efficacy in astrocytic tumour grading as dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI), and the grading accuracy may be further improved when combined with apparent diffusion coefficient (ADC) values. Forty-three patients with astrocytic tumours were studied using diffusion weighted imaging (DWI), pCASL, and DSC-PWI. Histograms of ADC and normalized tumour cerebral blood flow values (nCBF on pCASL and nrCBF on DSC-PWI) were measured and analyzed. The mean 10 % ADC value was the DWI parameter that provided the best differentiation between low-grade astrocytoma (LGA) and high-grade astrocytoma (HGA). The nCBF and nrCBF (1.810 ± 0.979 and 2.070 ± 1.048) in LGA were significantly lower than those (4.505 ± 2.270 and 5.922 ± 2.630) in HGA. For differentiation between LGA and HGA, the cutoff values of 0.764 x 10{sup -3} mm{sup 2}/s for mean 10 % ADC, 2.374 for nCBF, and 3.464 for nrCBF provided the optimal accuracy (74.4 %, 86.1 %, and 88.6 %, respectively). Combining the ADC values with nCBF or nrCBF could further improve the grading accuracy to 97.7 % or 95.3 %, respectively. pCASL is an alternative to DSC-PWI for astrocytic tumour grading. The combination of DWI and contrast-free pCASL offers a valuable choice in patients with risk factors. (orig.)

  5. Oxygen transfer in human carotid artery bifurcation

    Institute of Scientific and Technical Information of China (English)

    Z.G.Zhang; Y.B.Fan; X.Y.Deng

    2007-01-01

    Arterial bifurcations are places where blood flow may be disturbed and slow recirculation flow may occur.To reveal the correlation between local oxygen transfer and atherogenesis, a finite element method was employed to simulate the blood flow and the oxygen transfer in the human carotid artery bifurcation. Under steady-state flow conditions, the numerical simulation demonstrated a variation in local oxygen transfer at the bifurcation, showing that the convective condition in the disturbed flow region may produce uneven local oxygen transfer at the blood/wall interface.The disturbed blood flow with formation of slow eddies in the carotid sinus resulted in a depression in oxygen supply to the arterial wall at the entry of the sinus, which in turn may lead to an atherogenic response of the arterial wall, and contribute to the development of atherosclerotic stenosis there.

  6. Chronoecological health watch of arterial stiffness and neuro-cardio-pulmonary function in elderly community at high altitude (3524 m), compared with Japanese town.

    Science.gov (United States)

    Otsuka, K; Norboo, T; Otsuka, Y; Higuchi, H; Hayajiri, M; Narushima, C; Sato, Y; Tsugoshi, T; Murakami, S; Wada, T; Ishine, M; Okumiya, K; Matsubayashi, K; Yano, S; Chogyal, T; Angchuk, D; Ichihara, K; Cornélissen, G; Halberg, F

    2005-10-01

    Effects of high altitude on arterial stiffness and neuro-cardio-pulmonary function were studied. Blood pressure (BP) and heart rate (HR) were measured in a sitting position on resting Ladakhis, living at an altitude of 3250-4647 m (Phey village, 3250 m: 17 men and 55 women; Chumathang village, 4193 m: 29 men and 47 women; Sumdo village, 4540 m: 38 men and 57 women; and Korzok village, 4647 m: 84 men and 70 women). The neuro-cardio-pulmonary function, including the Kohs block design test, the Up and Go, the Functional Reach and the Button tests, was examined in 40 elderly subjects (19 men and 21 women, mean age: 74.7 +/- 3.3 years) in Leh, Ladakh (altitude: 3524 m), for comparison with 324 elderly citizens (97 men and 227 women, mean age: 80.7 +/- 4.7 years) of Tosa, Japan (altitude: 250 m). Cardio-Ankle Vascular Index (CAVI) was measured as the heart-ankle pulse wave velocity (PWV) in these subjects using a VaSera CAVI instrument (Fukuda Denshi, Tokyo). SpO(2) decreased while Hb and diastolic BP increased with increasing altitude. At higher altitude, residents were younger and leaner. Women in Leh vs. Tosa had a poorer cognitive function, estimated by the Kohs block design test (3.7 +/- 3.6 vs. 16.4 +/- 9.6 points, P high altitude (60-s estimation with counting: 41.1% shorter in men and 23.0% shorter in women). A higher voltage of the QRS complex was observed in the ECG of Leh residents, but two times measurement of CAVI showed no statistically significant differences between Leh and Tosa (two times of CAVI measures; 9.49 vs. 10.01 m/s and 9.41 vs. 10.05 m/s, respectively), suggesting that most residents succeed to adapt sufficiently to the high-altitude environment. However, correlation of CAVI with age shows several cases who show an extreme increase in CAVI. Thus, for the prevention of stroke and other adverse cardiovascular outcomes, including dementia, CAVI may be very useful, especially at high altitude. In conclusion, elderly people living at high altitude

  7. A case-controlled evaluation of the Medtronic Resting Heart System compared with conventional cardiopulmonary bypass in patients undergoing isolated coronary artery bypass surgery†

    OpenAIRE

    Nozohoor, Shahab; Johnsson, Per; Scicluna, Sara; Wallentin, Per; Andell, Elisabeth; Nilsson, Johan

    2012-01-01

    The Medtronic Resting Heart System (RHS) is a heparin-coated, closed perfusion circuit. Clinical results indicate less haemodilution and reduced complement activation, when compared with a traditional circuit leading to fewer postoperative blood transfusions. We evaluated the potential clinical benefits, including reduced transfusion requirements, when using the RHS compared with conventional cardiopulmonary bypass (cCPB). The study group (n = 330) consisted of patients undergoing isolated co...

  8. Locally finite profinite rings

    OpenAIRE

    Dobrowolski, Jan; Krupiński, Krzysztof

    2013-01-01

    We investigate the structure of locally finite profinite rings. We classify (Jacobson-) semisimple locally finite profinite rings as products of complete matrix rings of bounded cardinality over finite fields, and we prove that the Jacobson radical of any locally finite profinite ring is nil of finite nilexponent. Our results apply to the context of small compact $G$-rings, where we also obtain a description of possible actions of $G$ on the underlying ring.

  9. Convergence acceleration for partitioned simulations of the fluid-structure interaction in arteries

    Science.gov (United States)

    Radtke, Lars; Larena-Avellaneda, Axel; Debus, Eike Sebastian; Düster, Alexander

    2016-02-01

    We present a partitioned approach to fluid-structure interaction problems arising in analyses of blood flow in arteries. Several strategies to accelerate the convergence of the fixed-point iteration resulting from the coupling of the fluid and the structural sub-problem are investigated. The Aitken relaxation and variants of the interface quasi-Newton -least-squares method are applied to different test cases. A hybrid variant of two well-known variants of the interface quasi-Newton-least-squares method is found to perform best. The test cases cover the typical boundary value problem faced when simulating the fluid-structure interaction in arteries, including a strong added mass effect and a wet surface which accounts for a large part of the overall surface of each sub-problem. A rubber-like Neo Hookean material model and a soft-tissue-like Holzapfel-Gasser-Ogden material model are used to describe the artery wall and are compared in terms of stability and computational expenses. To avoid any kind of locking, high-order finite elements are used to discretize the structural sub-problem. The finite volume method is employed to discretize the fluid sub-problem. We investigate the influence of mass-proportional damping and the material model chosen for the artery on the performance and stability of the acceleration strategies as well as on the simulation results. To show the applicability of the partitioned approach to clinical relevant studies, the hemodynamics in a pathologically deformed artery are investigated, taking the findings of the test case simulations into account.

  10. Convergence acceleration for partitioned simulations of the fluid-structure interaction in arteries

    Science.gov (United States)

    Radtke, Lars; Larena-Avellaneda, Axel; Debus, Eike Sebastian; Düster, Alexander

    2016-06-01

    We present a partitioned approach to fluid-structure interaction problems arising in analyses of blood flow in arteries. Several strategies to accelerate the convergence of the fixed-point iteration resulting from the coupling of the fluid and the structural sub-problem are investigated. The Aitken relaxation and variants of the interface quasi-Newton -least-squares method are applied to different test cases. A hybrid variant of two well-known variants of the interface quasi-Newton-least-squares method is found to perform best. The test cases cover the typical boundary value problem faced when simulating the fluid-structure interaction in arteries, including a strong added mass effect and a wet surface which accounts for a large part of the overall surface of each sub-problem. A rubber-like Neo Hookean material model and a soft-tissue-like Holzapfel-Gasser-Ogden material model are used to describe the artery wall and are compared in terms of stability and computational expenses. To avoid any kind of locking, high-order finite elements are used to discretize the structural sub-problem. The finite volume method is employed to discretize the fluid sub-problem. We investigate the influence of mass-proportional damping and the material model chosen for the artery on the performance and stability of the acceleration strategies as well as on the simulation results. To show the applicability of the partitioned approach to clinical relevant studies, the hemodynamics in a pathologically deformed artery are investigated, taking the findings of the test case simulations into account.

  11. Arterial function of carotid and brachial arteries in postmenopausal vegetarians

    Directory of Open Access Journals (Sweden)

    Jeng JS

    2011-08-01

    Full Text Available Ta-Chen Su1, Pao-Ling Torng2, Jiann-Shing Jeng3, Ming-Fong Chen1, Chiau-Suong Liau1,41Division of Cardiology, Department of Internal Medicine, 2Department of Obstetrics and Gynecology, 3Department of Neurology, National Taiwan University Hospital, National Taiwan University College of Medicine, 4Cardiovascular Center, Taipei Buddist Tzu-Chi Hospital, Hsin-Dian, Taipei, TaiwanBackground: Vegetarianism is associated with a lower risk of cardiovascular disease. However, studies of arterial function in vegetarians are limited.Methods: This study investigated arterial function in vegetarianism by comparing 49 healthy postmenopausal vegetarians with 41 age-matched omnivores. The arterial function of the common carotid artery was assessed by carotid duplex, while the pulse dynamics method was used to measure brachial artery distensibility (BAD, compliance (BAC, and resistance (BAR. Fasting blood levels of glucose, lipids, lipoprotein (a, high-sensitivity C-reactive protein, homocysteine, and vitamin B12 were also measured.Results: Vegetarians had significantly lower serum cholesterol, high-density and low-density lipoprotein, and glucose compared with omnivores. They also had lower vitamin B12 but higher homocysteine levels. Serum levels of lipoprotein (a and high-sensitivity C-reactive protein were no different between the two groups. There were no significant differences in carotid beta stiffness index, BAC, and BAD between the two groups even after adjustment for associated covariates. However, BAR was significantly lower in vegetarians than in omnivores. Multiple linear regression analysis revealed that age and pulse pressure were two important determinants of carotid beta stiffness index and BAD. Vegetarianism is not associated with better arterial elasticity.Conclusion: Apparently healthy postmenopausal vegetarians are not significantly better in terms of carotid beta stiffness index, BAC, and BAD, but have significantly decreased BAR than

  12. Independent component analysis applied to pulse oximetry in the estimation of the arterial oxygen saturation (SpO2) - a comparative study

    DEFF Research Database (Denmark)

    Jensen, Thomas; Duun, Sune Bro; Larsen, Jan; Haahr, Rasmus Grønbek; Toft, M. H.; Belhage, B.; Thomsen, Erik Vilain

    2009-01-01

    ), and Mean Field ICA (ICAMF). The signal processing includes pre-processing bandpass filtering to eliminate noise, and post-processing by calculating the SpO2. The algorithms are compared to the commercial state-of-the-art algorithm Discrete Saturation Transform (DST) by Masimo Corporation. It is...

  13. Original Research: Sickle cell anemia and pediatric strokes: Computational fluid dynamics analysis in the middle cerebral artery.

    Science.gov (United States)

    Rivera, Christian P; Veneziani, Alessandro; Ware, Russell E; Platt, Manu O

    2016-04-01

    Children with sickle cell anemia (SCA) have a high incidence of strokes, and transcranial Doppler (TCD) identifies at-risk patients by measuring blood velocities in large intracerebral arteries; time-averaged mean velocities greater than 200 cm/s confer high stroke risk and warrant therapeutic intervention with blood transfusions. Our objective was to use computational fluid dynamics to alter fluid and artery wall properties, to simulate scenarios causative of significantly elevated arterial blood velocities. Two-dimensional simulations were created and increasing percent stenoses were created in silico, with their locations varied among middle cerebral artery (MCA), internal carotid artery (ICA), and anterior cerebral artery (ACA). Stenoses placed in the MCA, ICA, or ACA generated local increases in velocity, but not sufficient to reach magnitudes > 200 cm/s, even up to 75% stenosis. Three-dimensional reconstructions of the MCA, ICA, and ACA from children with SCA were generated from magnetic resonance angiograms. Using finite element method, blood flow was simulated with realistic velocity waveforms to the ICA inlet. Three-dimensional reconstructions revealed an uneven, internal arterial wall surface in children with SCA and higher mean velocities in the MCA up to 145 cm/s compared to non-SCA reconstructions. There were also greater areas of flow recirculation and larger regions of low wall shear stress. Taken together, these bumps on the internal wall of the cerebral arteries could create local flow disturbances that, in aggregate, could elevate blood velocities in SCA. Identifying cellular causes of these microstructures as adhered blood cells or luminal narrowing due to endothelial hyperplasia induced by disturbed flow would provide new targets to treat children with SCA. The preliminary qualitative results provided here point out the critical role of 3D reconstruction of patient-specific vascular geometries and provide qualitative insight to complex

  14. Megadolicho vascular malformation of the intracranial arteries.

    Science.gov (United States)

    Lodder, J; Janevski, B; van der Lugt, P J

    1981-01-01

    A patient is presented suffering a hemiparesis. Megadolicho-vascular malformation of the intracranial part of the internal carotid arteries and some of its branches and of the basilar artery was suggested by CT and confirmed by angiography. The value of CT compared with angiography in relation to intracranial megadolicho vascular malformations is discussed. PMID:6273040

  15. Computational analysis of anterior communicating artery aneurysm shear stress before and after aneurysm formation

    Science.gov (United States)

    Castro, Marcelo A.; Putman, Christopher M.; Cebral, Juan R.

    2011-12-01

    It is widely accepted that complexity in the flow pattern at the anterior communicating artery (AComA) is associated with the high rate of aneurysm formation at that location observed in large studies. The purpose of this work is to study associations between hemodynamic patterns, and AComA aneurysm initiation by comparing hemodynamics in the aneurysm and the normal model where the aneurysm was computationally removed. Vascular models of both right and left circulation were independently reconstructed from three-dimensional rotational angiography images using deformable models after image registration of both images, and fused using a surface merging algorithm. The geometric models were then used to generate high-quality volumetric finite element grids of tetrahedra with an advancing front technique. For each patient, the second anatomical model was created by digitally removing the aneurysm. It was iteratively achieved by applying a Laplacian smoothing filter and remeshing the surface. Finite element blood flow numerical simulations were performed for both the pathological and normal models under the same personalized pulsatile flow conditions imposed at the inlets of both models. The Navier-Stokes equations were numerically integrated by using a finite-element formulation. It was observed that aneurysms initiated in regions of high and moderate WSS in the counterpart normal models. Adjacent or close to those regions, low WSS portions of the arterial wall were not affected by the disease. These results are in line with previous observations at other vascular locations.

  16. [A comparative evaluation of the importance of transesophageal electrical stimulation of the left atrium and of bicycle ergometry in the diagnosis of ischemic heart disease in patients with arterial hypertension].

    Science.gov (United States)

    Azizov, V A; Gorshkov, A Sh; Kivaeva, G M; Gadzhiev, R Sh; Bekzhigitov, S B; Arabidze, G G; At'kov, O Iu

    1992-07-01

    To make a comparative assessment of transesophageal left atrial pacing (TLAP) and bicycle ergometry (BE) in the diagnosis of coronary heart disease (CHD) in patients with arterial hypertension (AH) of different origin, the authors examined 56 patients. The patients underwent TLAP and selective coronary angiography, of them 39 patients had BE testing. No significant differences were found in their specificity (73 and 78%) and sensitivity (92 and 81%) between TLAP and BE, respectively. The maximum heart rate in CHD patients with AH was significantly higher (130 +/- 6 per min) during TLAP than that in BE (112 +/- 5 per min, p > 0.05), ischemic changes occurring at the same value of double product despite the mode of myocardial ischemia induction in these functional tests (240 +/- 10 and 236 +/- 12 arbitrary units, respectively; p < 0.05). The mean systolic blood pressure was higher in TLAP and in BE (210 +/- 10 and 185 +/- 8 mm Hg). This follows that TLAP and BE finding are comparable and no profound changes occur in TLAP, hence it can be recommended for wide application in the diagnosis of CHD in AH patients. PMID:1487876

  17. A finite landscape?

    International Nuclear Information System (INIS)

    We present evidence that the number of string/M theory vacua consistent with experiments is finite. We do this both by explicit analysis of infinite sequences of vacua and by applying various mathematical finiteness theorems. (author)

  18. Finite Pluricomplex energy measures

    OpenAIRE

    Di Nezza, Eleonora

    2015-01-01

    We investigate probability measures with finite pluricomplex energy. We give criteria insuring that a given measure has finite energy and test these on various examples. We show that this notion is a biholomorphic but not a bimeromorphic invariant.

  19. Matrices and finite quandles

    OpenAIRE

    Ho, Benita; Nelson, Sam

    2005-01-01

    Finite quandles with n elements can be represented as n-by-n matrices. We show how to use these matrices to distinguish all isomorphism classes of finite quandles for a given cardinality n, as well as how to compute the automorphism group of each finite quandle. As an application, we classify finite quandles with up to 5 elements and compute the automorphism group for each quandle.

  20. Relaxed incremental variational approach for the modeling of damage-induced stress hysteresis in arterial walls.

    Science.gov (United States)

    Schmidt, Thomas; Balzani, Daniel

    2016-05-01

    In this paper, a three-dimensional relaxed incremental variational damage model is proposed, which enables the description of complex softening hysteresis as observed in supra-physiologically loaded arterial tissues, and which thereby avoids a loss of convexity of the underlying formulation. The proposed model extends the relaxed formulation of Balzani and Ortiz [2012. Relaxed incremental variational formulation for damage at large strains with application to fiber-reinforced materials and materials with truss-like microstructures. Int. J. Numer. Methods Eng. 92, 551-570], such that the typical stress-hysteresis observed in arterial tissues under cyclic loading can be described. This is mainly achieved by constructing a modified one-dimensional model accounting for cyclic loading in the individual fiber direction and numerically homogenizing the response taking into account a fiber orientation distribution function. A new solution strategy for the identification of the convexified stress potential is proposed based on an evolutionary algorithm which leads to an improved robustness compared to solely Newton-based optimization schemes. In order to enable an efficient adjustment of the new model to experimentally observed softening hysteresis, an adjustment scheme using a surrogate model is proposed. Therewith, the relaxed formulation is adjusted to experimental data in the supra-physiological domain of the media and adventitia of a human carotid artery. The performance of the model is then demonstrated in a finite element example of an overstretched artery. Although here three-dimensional thick-walled atherosclerotic arteries are considered, it is emphasized that the formulation can also directly be applied to thin-walled simulations of arteries using shell elements or other fiber-reinforced biomembranes. PMID:26341795

  1. Comparing the Therapeutic Effects of Carvedilol and Metoprolol on Prevention of Atrial Fibrillation after Coronary Artery Bypass Surgery, a Double-Blind Study

    Directory of Open Access Journals (Sweden)

    Rozita Jalalian

    2014-09-01

    Full Text Available Background: Atrial Fibrillation (AF is a common complication after open heart surgery and is frequently associated with increased hospital stay, complications, and mortality rates. The effect of β-blockers on prevention of supraventricular arrhythmias has been confirmed in several prospective randomized studies. Objectives: This clinical trial aimed to compare the preventive effects of carvedilol and metoprolol on occurrence of AF after CABG surgery. Patients and Methods: This prospective, double-blind, randomized clinical trial was conducted on 150 patients (55 females, 95 males; mean age: 59 ± 10 years who underwent CABG surgery. The patients with no contraindication for β-blocker use were randomly divided into two groups of carvedilol and metoprolol Tartarate (n = 75. Treatment with β-blocker was started on the first postoperative day (metoprolol, 25 mg BD; carvedilol, 6.25 mg, BD and the dosage was regulated according to the patients’ hemodynamic response. All the patients were monitored 5 days after the surgery and incidence of AF and other complications was recorded in both groups. Results: AF was detected in 18 patients in the carvedilol group and 21 patients in the metoprolol group (P = 0.577. The results of Fisher Exact test showed no significant relationship between the type of the drug and the occurrence of AF (P < 0.05. Nevertheless, the prevalence of AF was higher in the renal failure group. AF was mostly recorded on the second and third days after the surgery. The results showed an association between old age and higher occurrence of AF. AF was recorded in 11 patients (14% in the metoprolol group and 9 ones (12% in the carvedilol group, with Left Ventricle Ejection Fraction (LVEF being between 35% and 45% (P = 0.587. However, no significant difference was found between the two groups in this regard. Conclusions: In the patients with sufficient ejection fraction, no difference was observed in using carvedilol or metoprolol in

  2. The comparative analysis of the two dimensional Laplace equation using the Galerkin finite element method with the exact solution for various domains (circular and rectangular with triangular elemental meshing

    Directory of Open Access Journals (Sweden)

    Sarah Balkissoon

    2015-02-01

    Full Text Available Laplace Equation is used in many areas of studies such as potential theory and the fundamental forces of nature, Newtonian theory of gravity and electrostatics. It is used in Probability theory and Markov Chains as well as potential flows in fluid mechanics. Laplace Equation is used in various research areas and for this reason, to determine an accurate solution to this equation is of importance. In this study, the Finite Element Method is used to approximate the solution of the 2D Laplace Equation for two regions, circular and rectangular domains. These are compared to the exact solutions of the systems subjected to various physical restrictions; boundary conditions. This was done by using a mesh generator in Matlab, Distmesh, to obtain a mesh of triangular elements and then using Matlab to plot the exact and the approximated solutions as well as to determine the errors;   norm. For these domains, the number of elements in the mesh was incremented and it was noted there was a convergence of the approximated to the actual solution. The boundary conditions were altered to observe the changes in the regions' field variable distribution (intensity values of the Matlab plots.

  3. Variational collocation on finite intervals

    Science.gov (United States)

    Amore, Paolo; Cervantes, Mayra; Fernández, Francisco M.

    2007-10-01

    In this paper, we study a set of functions, defined on an interval of finite width, which are orthogonal and which reduce to the sinc functions when the appropriate limit is taken. We show that these functions can be used within a variational approach to obtain accurate results for a variety of problems. We have applied them to the interpolation of functions on finite domains and to the solution of the Schrödinger equation, and we have compared the performance of the present approach with others.

  4. A Bayesian Bootstrap for a Finite Population

    OpenAIRE

    Lo, Albert Y.

    1988-01-01

    A Bayesian bootstrap for a finite population is introduced; its small-sample distributional properties are discussed and compared with those of the frequentist bootstrap for a finite population. It is also shown that the two are first-order asymptotically equivalent.

  5. On the Compressibility of Arterial Tissue.

    Science.gov (United States)

    Nolan, D R; McGarry, J P

    2016-04-01

    Arterial tissue is commonly assumed to be incompressible. While this assumption is convenient for both experimentalists and theorists, the compressibility of arterial tissue has not been rigorously investigated. In the current study we present an experimental-computational methodology to determine the compressibility of aortic tissue and we demonstrate that specimens excised from an ovine descending aorta are significantly compressible. Specimens are stretched in the radial direction in order to fully characterise the mechanical behaviour of the tissue ground matrix. Additionally biaxial testing is performed to fully characterise the anisotropic contribution of reinforcing fibres. Due to the complexity of the experimental tests, which entail non-uniform finite deformation of a non-linear anisotropic material, it is necessary to implement an inverse finite element analysis scheme to characterise the mechanical behaviour of the arterial tissue. Results reveal that ovine aortic tissue is highly compressible; an effective Poisson's ratio of 0.44 is determined for the ground matrix component of the tissue. It is also demonstrated that correct characterisation of material compressibility has important implications for the calibration of anisotropic fibre properties using biaxial tests. Finally it is demonstrated that correct treatment of material compressibility has significant implications for the accurate prediction of the stress state in an artery under in vivo type loading. PMID:26297340

  6. A classification of finite quantum kinematics

    International Nuclear Information System (INIS)

    Quantum mechanics in Hilbert spaces of finite dimension N is reviewed from the number theoretic point of view. For composite numbers N possible quantum kinematics are classified on the basis of Mackey's Imprimitivity Theorem for finite Abelian groups. This yields also a classification of finite Weyl-Heisenberg groups and the corresponding finite quantum kinematics. Simple number theory gets involved through the fundamental theorem describing all finite discrete Abelian groups of order N as direct products of cyclic groups, whose orders are powers of not necessarily distinct primes contained in the prime decomposition of N. The representation theoretic approach is further compared with the algebraic approach, where the basic object is the corresponding operator algebra. The consideration of fine gradings of this associative algebra then brings a fresh look on the relation between the mathematical formalism and physical realizations of finite quantum systems

  7. Occlusive Peripheral Arterial Disease

    Science.gov (United States)

    ... erythrocyte sedimentation rate (ESR) and level of C-reactive protein, which is produced only when inflammation is present. ... people with occlusive peripheral arterial disease also have coronary artery disease. Amputation of a limb may be necessary if ...

  8. Sound radiation from finite surfaces

    DEFF Research Database (Denmark)

    Brunskog, Jonas

    2013-01-01

    A method to account for the effect of finite size in acoustic power radiation problem of planar surfaces using spatial windowing is developed. Cremer and Heckl presents a very useful formula for the power radiating from a structure using the spatially Fourier transformed velocity, which combined...... with spatially windowing of a plane waves can be used to take into account the finite size. In the present paper, this is developed by means of a radiation impedance for finite surfaces, that is used instead of the radiation impedance for infinite surfaces. In this way, the spatial windowing is...... included in the radiation formula directly, and no pre-windowing is needed. Examples are given for the radiation efficiency, and the results are compared with results found in the literature....

  9. Mixed finite element-finite volume methods

    OpenAIRE

    Zine Dine, Khadija; Achtaich, Naceur; Chagdali, Mohamed

    2010-01-01

    This paper is devoted to present a numerical methods for a model of incompressible and miscible flow in porous media. We analyze a numerical scheme combining a mixed finite element method (MFE) and finite volume scheme (FV) for solving a coupled system includes an elliptic equation (pressure and velocity) and a linear convection-diffusion equation (concentration). The (FV) scheme considered is "vertex centered" type semi implicit. We show that this scheme is $L^{\\infty...

  10. Combination of Rare Right Arterial Variation with Anomalous Origins of the Vertebral Artery, Aberrant Subclavian Artery and Persistent Trigeminal Artery

    Science.gov (United States)

    Ishihara, H.; San Millán Ruíz, D.; Abdo, G.; Asakura, F.; Yilmaz, H.; Lovblad, K.O.; Rüfenacht, D.A.

    2011-01-01

    Summary A 32-year-old woman hospitalized for subarachnoid hemorrhage showed rare arterial variation on the right side with anomalous origins of the vertebral artery, aberrant subclavian artery and persistent trigeminal artery. Angiography showed the right vertebral artery to originate from the right common carotid artery, the right subclavian artery to arise separately from the descending aorta, and persistent trigeminal artery on the right side. The possible embryonic mechanism of this previously unreported variant combination is discussed. PMID:22005696

  11. Pre and post operative evaluation of the perfusion reserve by acetazolamide [sup 99m]Tc-HMPAO SPECT in patients with chronic occlusive cerebral arteries. A comparative study with PET

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, Yasuo; Ichiya, Yuichi; Sasaki, Masayuki; Akashi, Yuko; Yoshida, Tsuyoshi; Fukumura, Toshimitsu; Masuda, Kouji; Fujii, Kiyotaka; Fukui, Masashi (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1994-09-01

    We studied the pre and post-operative perfusion reserve using Diamox [sup 99m]Tc-HMPAO SPECT in 7 patients with chronic occlusive cerebral arteries and then compared the results with PET. STAMCA anastomosis was performed on 5 patients, while a carotid endarterectomy was done on 2 patients. The cerebral blood flow, the vascular response to CO[sub 2] or Diamox, the oxygen extraction fraction and transit time (CBV/CBF) were measured by PET. In the pre-operative state, the visual evaluations for hypoperfusion area at rest agreed in 5 out of 7 patients in HMPAO SPECT and PET studies. In the remaining 2 patients, hypoperfusion areas were only detected in the PET study. The pre-operative evaluation of perfusion reserve agreed in 2 patients. In the remaining 5 patients, 3 patients showed definite positive (++) in PET and positive (+) in HMPAO SPECT, and one patient showed positive (+) in PET and negative (-) in HMPAO SPECT. The post-operative change of hypoperfusion areas well agreed in HMPAO SPECT and PET studies. However, the change of perfusion reserve was underestimated in HMPAO SPECT compared with PET. In the semiquantitative and quantitative analyses, the count rate ratios (affected/unaffected side) in HMPAO SPECT were apparently higher than those of CBF in PET. The postoperative change of the count rate ratios in HMPAO SPECT were smaller than those of CBF in PET. There was no significant correlation between the change in the ratio of the HMPAO SPECT after the administration of Diamox and the oxygen extraction fraction, and it was thus thought to be impossible to predict the areas with an increased oxygen extraction fraction. Thus, Diamox HMPAO SPECT may underestimate the areas of hypoperfusion or decrease in perfusion reserve when compared with PET. We should consider these limitations in the evaluation of pre and post operative cerebral hemodynamics. (author).

  12. Volumetric-modulated arc therapy for left-sided breast cancer and all regional nodes improves target volumes coverage and reduces treatment time and doses to the heart and left coronary artery, compared with a field-in-field technique

    International Nuclear Information System (INIS)

    We compared two intensity-modulated radiotherapy techniques for left-sided breast treatment, involving lymph node irradiation including the internal mammary chain. Inverse planned arc-therapy (VMAT) was compared with a forward-planned multi-segment technique with a mono-isocenter (MONOISO). Ten files were planned per technique, delivering a 50-Gy dose to the breast and 46.95 Gy to nodes, within 25 fractions. Comparative endpoints were planning target volume (PTV) coverage, dose to surrounding structures, and treatment delivery time. PTV coverage, homogeneity and conformality were better for two arc VMAT plans; V95%PTV-T was 96% for VMAT vs 89.2% for MONOISO. Homogeneity index (HI)PTV-T was 0.1 and HIPTV-N was 0.1 for VMAT vs 0.6 and 0.5 for MONOISO. Treatment delivery time was reduced by a factor of two using VMAT relative to MONOISO (84 s vs 180 s). High doses to organs at risk were reduced (V30left lung = 14% using VMAT vs 24.4% with MONOISO; dose to 2% of the volume (D2%)heart = 26.1 Gy vs 32 Gy), especially to the left coronary artery (LCA) (D2%LCA = 34.4 Gy vs 40.3 Gy). However, VMAT delivered low doses to a larger volume, including contralateral organs (mean dose [Dmean]right lung = 4 Gy and Dmeanright breast = 3.2 Gy). These were better protected using MONOISO plans (Dmeanright lung = 0.8 Gy and Dmeanright breast = 0.4 Gy). VMAT improved PTV coverage and dose homogeneity, but clinical benefits remain unclear. Decreased dose exposure to the LCA may be clinically relevant. VMAT could be used for complex treatments that are difficult with conventional techniques. Patient age should be considered because of uncertainties concerning secondary malignancies. (author)

  13. On Renal Artery Stenosis

    OpenAIRE

    Eklöf, Hampus

    2005-01-01

    Renal artery stenosis (RAS) is a potentially curable cause of hypertension and azotemia. Besides intra-arterial renal angiography there are several non-invasive techniques utilized to diagnose patients with suspicion of renal artery stenosis. Removing the stenosis by revascularization to restore unobstructed blood flow to the kidney is known to improve and even cure hypertension/azotemia, but is associated with a significant complication rate. To visualize renal arteries with x-ray technique...

  14. Long-term results of interventional treatment of large unresectable hepatocellular carcinoma (HCC): significant survival benefit from combined transcatheter arterial chemoembolization (TACE) and percutaneous ethanol injection (PEI) compared to TACE monotherapy

    International Nuclear Information System (INIS)

    Purpose: A retrospective analysis of long-term efficacy of combined transcatheter arterial chemoembolization (TACE) and percutaneous ethanol injection (PEI) and TACE monotherapy was conducted in patients with large, non-resectable hepatocellular carcinoma (HCC). Methods and Materials: Fifty patients with large, unresectable HCC lesions underwent selective TACE. Liver cirrhosis was present in 42 patients, due to alcohol abuse (n = 22) and viral infection (n = 17). In three patients, the underlying cause for liver cirrhosis remained unclear. Child A cirrhosis was found in 22 and Child B cirrhosis in 20 patients. Repeated and combined TACE and PEI were performed in 22 patients and repeated TACE monotherapy was performed in 28 patients. Survival and complication rates were determined and compared. Results: The 6-, 12-, 24- and 36-month survival rates were 61%, 21%, 4%, and 4% for TACE monotherapy and 77%, 55%, 39% and 22% for combined TACE and PEI (Kaplan-Meier method). The kind of treatment significantly affected the survival rate (p=0.002 log-rank test). Severe side effects were present in two patients of the monotherapy group and in three patients of the combination therapy group. (orig.)

  15. Peripheral Artery Disease

    Science.gov (United States)

    ... or atherectomy may be used to help improve blood flow. What is peripheral artery disease (PAD)? How is peripheral artery disease evaluated? How ... PAD are diabetes, smoking, high cholesterol and high blood pressure. Most cases occur in ... is peripheral artery disease evaluated? Several imaging tests can be used to ...

  16. Retinal artery occlusion

    Science.gov (United States)

    ... artery occlusion; Branch retinal artery occlusion; CRAO; BRAO Images Retina References Sanborn GE, Magargal LE. Arterial obstructive disease ... A.M. Editorial team. Related MedlinePlus Health Topics ... audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among ...

  17. Percutaneous transluminal angioplasty of the superficial femoral artery by retrograde catheterization via the popliteal artery

    DEFF Research Database (Denmark)

    Tønnesen, K H; Sager, P; Karle, A; Henriksen, L; Jørgensen, B

    1988-01-01

    We report the results of 50 angioplasty procedures via the popliteal artery. A 3-year follow-up including control of blood pressures at ankle and toe levels show results comparable to reports in the literature. This new approach for angioplasty of the superficial femoral artery and eventually of ...

  18. Duplication of hepatic artery

    Directory of Open Access Journals (Sweden)

    Saeed Muhammad

    2001-01-01

    Full Text Available Background: The hepatic arterial anatomy is aberrant in almost 33-41% of individuals. The variant arterial anatomy recognized during routine cadaveric dissection offers great learning potential. Such findings provide an alternative perspective to view common morphology and its structural and functional importance. These impart the concept of patient individuality and subsequent individualization of medical and surgical therapies. Adequate knowledge of normal and abnormal arterial anatomy is essential for peripancreatic surgery and liver transplantation. Aims of the study: To report on hepatic artery variations observed in the dissecting room and to find out the macroscopic pattern of varied human hepatic arterial vascularization by cadaveric dissection. Patients and Methods: Twenty human cadavers of caucasian origin were dissected to study the source and topographic pattern of hepatic arterial supply. Results: Nineteen cadavers exhibited typical hepatic arterial supply from the celiac axis. Only one female body out of twenty cadavers exhibited a dual arterial supply to all parts of liver and gallbladder. One artery originated from the celiac axis whereas the other was given off by the superior mesenteric artery. Conclusion: No doubt, aberrant hepatic vascularization should be assessed preoperatively by invasive and noninvasive techniques to avoid fatal complications, but we favour careful dissection over angiography as a means of defining the arterial anatomy.

  19. Acute occlusion of the left subclavian artery with artery dissection

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Subclavian steal syndrome is cerebral or brain stem ischemia resulting from diversion of blood flow from the basilar artery to the subclavian artery, which is caused by occlusive disease of either the subclavian artery or the innominate artery before they branch off at the vertebral artery. In the patients with subclavian steal syndrome the subclavian artery is fed by retrograde flow from the vertebral artery via the carotids and the circle of Willis.

  20. Intra-arterial port implantation for intra-arterial chemotherapy : comparison between PIPS(Percutaneously Implantable Port System) and port system

    International Nuclear Information System (INIS)

    To compare the techniques and complications of intra-arterial port implantation for intra-arterial chemotherapy between PIPS and the port system. For intra-arterial port implantation, 27 cases in 27 patients were retrospectively evaluated using PIPS(PIPS-200, William Cook Europe, Denmark) while for 21 cases in 19 patients a pediatric venous port system(Port-A-Cath, 5.8F, SIMS Deltec, U. S. A.) was used. All intra-arterial port implantation was performed percuteneously in an angiographic ward. Hepatocellular carcinoma was diagnosed in 18 patients and hepatic metastasis in 16. Peripheral cholangiocarcinoma, and pancreatic gastric, ovarian, renal cell and colon carcinoma were included. We compared the techniques and complications between PIPS and the port system. The follow up period ranged from 23 to 494(mean, 163) days in PIPS and from 12 to 431(mean, 150) days in the port system. In all cases, intra-arterial port implantations were technically successful. Port catheter tips were located in the common hepatic artery(n=8), proper hepatic artery(n=7), right hepatic artery(n=5), gastroduodenal artery(n=2), left hepatic artery(n=1), pancreaticoduodenal artery(n=1), inferior mesenteric artery(n=1), lumbar artery(n=1), and renal artery(n=1) in PIPS, and in the proper hepatic artery(n=6), gastroduodenal artery(n=6), common hepatic artery(n=3), right hepatic artery(n=4), inferior mesenteric artery(n=1), and internal iliac artery(n=1) in the port system. Port chambers were buried in infrainguinal subcutaneous tissue. Using PIPS, complications developed in seven cases(25.9%) and of these, four (57.1%) were catheter or chamber related. In the port system, catheter or chamber related complications developed in four cases(19.0%). Because PIPS and the port system have relative merits and demetrits, successful intra-arterial port implantation is possible if equipment is properly selected

  1. Simple Finite Jordan Pseudoalgebras

    Directory of Open Access Journals (Sweden)

    Pavel Kolesnikov

    2009-01-01

    Full Text Available We consider the structure of Jordan H-pseudoalgebras which are linearly finitely generated over a Hopf algebra H. There are two cases under consideration: H = U(h and H = U(h # C[Γ], where h is a finite-dimensional Lie algebra over C, Γ is an arbitrary group acting on U(h by automorphisms. We construct an analogue of the Tits-Kantor-Koecher construction for finite Jordan pseudoalgebras and describe all simple ones.

  2. Simple Finite Jordan Pseudoalgebras

    Science.gov (United States)

    Kolesnikov, Pavel

    2009-01-01

    We consider the structure of Jordan H-pseudoalgebras which are linearly finitely generated over a Hopf algebra H. There are two cases under consideration: H = U(h) and H = U(h) # C[Γ], where h is a finite-dimensional Lie algebra over C, Γ is an arbitrary group acting on U(h) by automorphisms. We construct an analogue of the Tits-Kantor-Koecher construction for finite Jordan pseudoalgebras and describe all simple ones.

  3. Handbook of finite fields

    CERN Document Server

    Mullen, Gary L

    2013-01-01

    Poised to become the leading reference in the field, the Handbook of Finite Fields is exclusively devoted to the theory and applications of finite fields. More than 80 international contributors compile state-of-the-art research in this definitive handbook. Edited by two renowned researchers, the book uses a uniform style and format throughout and each chapter is self contained and peer reviewed. The first part of the book traces the history of finite fields through the eighteenth and nineteenth centuries. The second part presents theoretical properties of finite fields, covering polynomials,

  4. The new technique of using the epigastric arteries in renal transplantation with multiple renal arteries

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Amirzargar

    2013-01-01

    Full Text Available The most common anatomic variant seen in the donor kidneys for renal transplantation is multiple renal arteries (MRA, which can cause an increased risk of complications. We describe the long-term outcomes of 16 years of experience in 76 kidney transplantations with MRAs. In a new reconstruction technique, we remove arterial clamps after anastomosing the donor to the recipient′s main renal vessels, which cause backflow from accessory arteries to prevent thrombosis. By this technique, we reduce the ischemic times as well as the operating times. Both in live or cadaver donor kidneys, lower polar arteries were anastomosed to the inferior epigastric artery and upper polar arteries were anastomosed to the superior epigastric arteries. Injection of Papaverine and ablation of sympathic nerves of these arteries dilate and prevent them from post-operative spasm. Follow-up DTPA renal scan in all patients showed good perfusion and function of the transplanted kidney, except two cases of polar arterial thrombosis. Mean creatinine levels during at least two years of follow-up remained acceptable. Patient and graft survival were excellent. No cases of ATN, hypertension, rejection and urologic complications were found. In conclusion, this technique can be safely and successfully utilized for renal transplantation with kidneys having MRAs, and may be associated with a lower complication rate and better graft function compared with the existing techniques.

  5. Estudo comparativo entre efedrina e etilefrina como vasopressor para correção da hipotensão arterial materna em cesarianas eletivas com raquianestesia Estudio comparativo entre efedrina y etilefrina como vasopresor para correción de la hipotensión materna en cesáreas electivas con raquianestesia Ephedrine and etilefrine as vasopressor to correct maternal arterial hypotension during elective cesarean section under spinal anesthesia. Comparative study

    Directory of Open Access Journals (Sweden)

    Sérgio D. Belzarena

    2006-06-01

    grupos iguales. Todas recibieron raquianestesia con bupivacaína, fentanil y morfina. Se les midió la presión arterial no invasiva y la frecuencia cardiaca. Los recién nacidos fueron evaluados con el índice de Apgar. La incidencia de hipotensión arterial, la cantidad de vasopresor necesaria para corrección y los efectos adversos fueron registrados. RESULTADOS: Ocurrió hipotensión arterial materna con frecuencia en los dos grupos, siendo un 68% del grupo etilefrina y un 63% del grupo efedrina. En la mayoría de las embrazadas, se corrigió con la primera dosis del vasopresor, sin diferencia entre los grupos (66% etilefrina, 58% efedrina. La hipotensión arterial necesitó dos o más dosis de vasopresor para ser corregida o se registró hipertensión reactiva en pocas pacientes (un 24% y un 10% del grupo etilefrina y 34% y 8% del grupo efedrina, respectivamente, sin diferencia estadística significativa. No hubo diferencia en los efectos adversos y en las pruebas de los recién nacidos. CONCLUSIONES: Con el método de administración empleado y con las dosis de vasopresor seleccionadas no hubo diferencia entre la efedrina y la etilefrina cuando se utilizaron para corregir la hipotensión arterial materna en cesáreas con raquianestesia.BACKGROUND AND OBJECTIVES: Ephedrine is the most popular vasopressor for obstetrics and etilefrine is widely used in regional anesthesia. This study aimed at comparing ephedrine and etilefrine to correct maternal arterial hypotension during elective Cesarean section under spinal anesthesia. METHODS: Participated in this study 120 pregnant patients who were randomly distributed in two equal groups. All patients received spinal anesthesia with bupivacaine, fentanyl and morphine. Noninvasive blood pressure and heart rate were monitored. Neonates were evaluated by the Apgar score. The incidence of hypotension, the amount of vasopressor needed to correct it and adverse effects were recorded. RESULTS: Maternal hypotension was similar in

  6. Surgical complications after renal transplantation in grafts with multiple arteries

    Directory of Open Access Journals (Sweden)

    Eduardo Mazzucchi

    2005-04-01

    Full Text Available INTRODUCTION: Renal transplantation with multiple arteries appears, in literature, associated to a major index of surgical complications. This study compared the surgical complications and short-term outcome renal transplants with multiple arteries and single artery grafts. MATERIALS AND METHODS: The data of 64 renal transplants with multiple arteries performed between January 1995 and December 1999 were compared to the ones of 292 transplants with single renal artery. The aspects analyzed were number of arteries of the graft, donor type, vascular reconstruction technique, the occurrence of surgical complications, the incidence of delayed graft function, graft function 1 month after transplantation, graft loss and the patients' deaths. RESULTS: The incidence of surgical complications in grafts with multiple arteries and single renal artery was respectively: vascular - 3.1% and 3.1%; urological - 6.3% and 2.7% and other surgical complications - 15.6% and 10.6%, respectively. The incidence of lymphoceles was 3.1% in grafts with a single artery and 12.5% in grafts with more than 1 artery (p = 0.0015. The incidence of delayed graft function in grafts with multiple arteries and with a single renal artery was respectively 35.1 and 29.1% (p = 0.295. Mean serum creatinine at the 30th postoperative day was 2.46 and 1.81 in grafts with multiple and with 1 artery, respectively (p=0.271. CONCLUSIONS: Kidney transplantation using grafts with single and multiple arteries present similar indexes of surgical complications and short-term outcome; lymphoceles were more frequent among grafts with multiple arteries.

  7. Effects of pressure on arterial failure.

    Science.gov (United States)

    Khamdaengyodtai, Pannathai; Vafai, Kambiz; Sakulchangsatjatai, Phrut; Terdtoon, Pradit

    2012-10-11

    A three-dimensional multilayer model of mechanical response for analyzing the effect of pressure on arterial failure is presented in this work. The multilayer arterial wall is considered to be composed of five different layers. The three-dimensional effects are incorporated within the five-concentric axisymmetric layers while incorporating the nonlinear elastic characteristics under combined extension and inflation. Constitutive equations for fiber-reinforced material are employed for three of the major layers, i.e., intima, media and adventitia and an isotropic material model is employed for the other two layers, i.e., endothelium and internal elastic lamina. Our own developed three-dimensional five-layer model has been utilized to model propagated rupture area of the arterial wall. Required parameters for each layer are obtained by using a nonlinear least square method fitted to in vivo non-invasive experimental data of human artery and the effects of pressure on arterial failure are examined. The solutions from our computational model are compared with previous studies and good agreements are observed. Local stresses and strain distributions across the deformed arterial wall are illustrated and consequently the rupture area is predicted by varying luminal pressure in the physiological range and beyond. The effects of pressure on the arterial failure have been interpreted based on this comprehensive three-dimensional five-layer arterial wall model. This is the first study which employs two constitutive equations and incorporates a five-layer arterial wall model in three-dimensions based on in vivo non-invasive experimental data for a human artery. PMID:22980577

  8. Finite-volume corrections to charge radii

    International Nuclear Information System (INIS)

    The finite-volume nature of lattice QCD entails a variety of effects that must be handled in the process of performing chiral extrapolations. Since the pion cloud that surrounds hadrons becomes distorted in a finite volume, hadronic observables must be corrected before one can compare with the experimental values. The electric charge radius of the nucleon is of particular interest when considering the implementation of finite-volume corrections. It is common practice in the literature to transform electric form factors from the lattice into charge radii prior to analysis. However, there is a fundamental difficulty with using these charge radii in a finite-volume extrapolation. The subtleties are a consequence of the absence of a continuous derivative on the lattice. A procedure is outlined for handling such finite-volume corrections, which must be applied directly to the electric form factors themselves rather than to the charge radii

  9. Superselective intra-arterial infusion via the superficial temporal artery and occipital artery for gingival carcinoma of the mandible. Simultaneous catheter placement to the maxillary artery and facial artery

    International Nuclear Information System (INIS)

    Superselective intra-arterial infusion via the superficial temporal artery (STA) has become useful for oral cancer. Approaching via the occipital artery (OA) enables superselective intra-arterial infusion when catheter placement via the STA is impossible. Therefore, simultaneous catheter placement via the STA and OA is possible. We report a surgical method of simultaneous catheter placement via the STA and OA to achieve retrograde superselective intra-arterial infusion for gingival carcinoma of the mandible. Preoperatively, three-dimensional computed tomography angiography was performed to identify the route of the external carotid artery and branches such as the STA, OA, maxillary artery, and facial artery (FA). Thirteen patients with mandibular gingival cancer underwent catheter placement via the STA and OA under local anesthesia. Catheter placement via the STA and OA was superselectively successful in all the patients. The mean operating time was 150.8 min. Catheter placed to the FA via the OA was dislocated during the treatment in one patient, and so the catheter was replaced. This method is useful to enable superselective intra-arterial chemotherapy to the whole gingival carcinoma of the mandible from the start of treatment compared with approaching via the STA. (author)

  10. Celiac Artery Compression Syndrome

    Directory of Open Access Journals (Sweden)

    Mohammed Muqeetadnan

    2013-01-01

    Full Text Available Celiac artery compression syndrome is a rare disorder characterized by episodic abdominal pain and weight loss. It is the result of external compression of celiac artery by the median arcuate ligament. We present a case of celiac artery compression syndrome in a 57-year-old male with severe postprandial abdominal pain and 30-pound weight loss. The patient eventually responded well to surgical division of the median arcuate ligament by laparoscopy.

  11. Popliteal artery entrapment syndrome.

    LENUS (Irish Health Repository)

    O'Leary, D P

    2010-01-01

    Popliteal artery entrapment syndrome is a rare abnormality of the anatomical relationship between the popliteal artery and adjacent muscles or fibrous bands in the popliteal fossa. The following is a case report of a 19 year old female, in whom popliteal artery entrapment syndrome was diagnosed, and successfully treated surgically. A review of literature is also presented and provides details on how PAES is classified, diagnosed both clinically and radiologically, and treated surgically.

  12. Coeliac artery compression syndrome

    OpenAIRE

    OKTAY, Özgür; MEMİŞ, Ahmet; Parildar, Mustafa; Oran, İsmail

    2003-01-01

    Celiac artery compression syndrome, also called median arcuate ligament compression syndrome, causes gastrointestinal ischemia secondary to compression of the proximal portion of the celiac artery just beyond its origin by the median arcuate ligament of the diaphragm. This syndrome is frequently demonstrated on aortography performed in patients without complaints of intestinal angina. Isolated stenosis or even occlusion of the celiac artery is always compensated for by collateral circul...

  13. Conduits for Coronary Bypass: Internal Thoracic Artery

    OpenAIRE

    Barner, Hendrick B.

    2012-01-01

    This second report in the series on coronary artery bypass presents the authors experience and personal views on the internal thoracic artery (ITA) which date to 1966. There has been a very gradual evolution in the acceptance of this conduit which was initially compared with the saphenous vein and viewed as an improbable alternative to it. As is common with concepts and techniques which are 'outside the box' there was skepticism and criticism of this new conduit which was more difficult and t...

  14. Physical inactivity and arterial stiffness in COPD

    OpenAIRE

    Sievi NA; Franzen D; Kohler M.; Clarenbach CF

    2015-01-01

    Noriane A Sievi,1 Daniel Franzen,1 Malcolm Kohler,1,2 Christian F Clarenbach1 1Division of Pulmonology, University Hospital of Zurich, 2Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland Background: Arterial stiffness is an important predictor of cardiovascular risk besides classic cardiovascular risk factors. Previous studies showed that arterial stiffness is increased in patients with COPD compared to healthy controls and exercise training may reduce ...

  15. Imaging the vertebral artery

    Energy Technology Data Exchange (ETDEWEB)

    Tay, Keng Yeow; U-King-Im, Jean Marie; Trivedi, Rikin A.; Higgins, Nicholas J.; Cross, Justin J.; Antoun, Nagui M. [Addenbrooke' s Hospital and University of Cambridge, Department of Radiology, Cambridge (United Kingdom); Davies, John R.; Weissberg, Peter L. [Addenbrooke' s Hospital and University of Cambridge, Division of Cardiovascular Medicine, Cambridge (United Kingdom); Gillard, Jonathan H. [Addenbrooke' s Hospital and University of Cambridge, Department of Radiology, Cambridge (United Kingdom); Addenbrooke' s Hospitald, University Department of Radiology, Cambridge (United Kingdom)

    2005-07-01

    Although conventional intraarterial digital subtraction angiography remains the gold standard method for imaging the vertebral artery, noninvasive modalities such as ultrasound, multislice computed tomographic angiography and magnetic resonance angiography are constantly improving and are playing an increasingly important role in diagnosing vertebral artery pathology in clinical practice. This paper reviews the current state of vertebral artery imaging from an evidence-based perspective. Normal anatomy, normal variants and a number of pathological entities such as vertebral atherosclerosis, arterial dissection, arteriovenous fistula, subclavian steal syndrome and vertebrobasilar dolichoectasia are discussed. (orig.)

  16. Peripheral artery disease - legs

    Science.gov (United States)

    ... if they have a history of: Abnormal cholesterol Diabetes Heart disease (coronary artery disease) High blood pressure ( hypertension ) Kidney disease involving hemodialysis Smoking Stroke ( cerebrovascular disease )

  17. Fluid-structure interaction simulations of cerebral arteries modeled by isotropic and anisotropic constitutive laws

    Science.gov (United States)

    Tricerri, Paolo; Dedè, Luca; Deparis, Simone; Quarteroni, Alfio; Robertson, Anne M.; Sequeira, Adélia

    2015-03-01

    This paper considers numerical simulations of fluid-structure interaction (FSI) problems in hemodynamics for idealized geometries of healthy cerebral arteries modeled by both nonlinear isotropic and anisotropic material constitutive laws. In particular, it focuses on an anisotropic model initially proposed for cerebral arteries to characterize the activation of collagen fibers at finite strains. In the current work, this constitutive model is implemented for the first time in the context of an FSI formulation. In this framework, we investigate the influence of the material model on the numerical results and, in the case of the anisotropic laws, the importance of the collagen fibers on the overall mechanical behavior of the tissue. With this aim, we compare our numerical results by analyzing fluid dynamic indicators, vessel wall displacement, Von Mises stress, and deformations of the collagen fibers. Specifically, for an anisotropic model with collagen fiber recruitment at finite strains, we highlight the progressive activation and deactivation processes of the fibrous component of the tissue throughout the wall thickness during the cardiac cycle. The inclusion of collagen recruitment is found to have a substantial impact on the intramural stress, which will in turn impact the biological response of the intramural cells. Hence, the methodology presented here will be particularly useful for studies of mechanobiological processes in the healthy and diseased vascular wall.

  18. Coronary artery bypass graft (CABG) surgery patients in a clinical pathway gained less in health-related quality of life as compared with patients who undergo CABG in a conventional-care plan

    NARCIS (Netherlands)

    El Baz, Noha; Middel, Berrie; van Dijk, Jitse P.; Boonstra, Piet W.; Reijneveld, Sijmen A.

    2009-01-01

    The aim of this study is to determine the difference between clinical pathway (CP) and conventional care in terms of health-related quality of life (HRQoL) domains, depression and anxiety, as well as to determine the relative contribution of CP towards an improved HRQoL after coronary artery bypass

  19. Residually finite algorithmically finite groups, their subgroups and direct products

    OpenAIRE

    Klyachko, Anton A.; Mongush, Ayrana K.

    2014-01-01

    We construct an infinite finitely generated recursively presented residually finite algorithmically finite group $G$ answering thereby a question of Myasnikov and Osin. Moreover, $G$ is "very infinite" and "very algorithmically finite" in the sense that $G$ contains an infinite abelian normal subgroup while all finite Cartesian powers of $G$ are algorithmically finite (i.e., for any positive integer $n$, there is no algorithm which writes out an infinite sequence of pairwise different element...

  20. Feeding Arteries of Primary Tongue Cancers on Intra-arterial Infusion Chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kamitani, Takeshi, E-mail: kamitani@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences (Japan); Kawanami, Satoshi, E-mail: kawanami-01@mac.com [Kyushu University, Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences (Japan); Asayama, Yoshiki, E-mail: asayama@radiol.med.kyushu-u.ac.jp; Matsuo, Yoshio, E-mail: yymatsuo@radiol.med.kyushu-u.ac.jp; Yonezawa, Masato, E-mail: ymasato@radiol.med.kyushu-u.ac.jp; Yamasaki, Yuzo, E-mail: yyama@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences (Japan); Nagao, Michinobu, E-mail: minagao@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences (Japan); Yamanouchi, Torahiko, E-mail: tora0228@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences (Japan); Yabuuchi, Hidetake, E-mail: h-yabu@med.kyushu-u.ac.jp [Kyushu University, Department of Health Sciences, Graduate School of Medical Sciences (Japan); Nakamura, Katsumasa, E-mail: nakam@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences (Japan); Nakashima, Torahiko, E-mail: nakatora@qent.med.kyushu-u.ac.jp [Kyushu University, Department of Otorhinolaryngology, Graduate School of Medical Sciences (Japan); Honda, Hiroshi, E-mail: honda@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences (Japan)

    2016-02-15

    PurposeTo evaluate the frequency and the predictive factor of each feeding artery on intra-arterial infusion chemotherapy (IAIC) in primary tongue cancer.Materials and MethodsWe retrospectively evaluated 20 patients who received IAIC for primary tongue cancer. The main and accompanying feeding arteries were identified on super-selective angiography of the branches of the external carotid artery. Tumor diameter, and extension to the contralateral side, tongue extrinsic muscles (TEMs), and lateral mesopharyngeal wall were determined based on magnetic resonance imaging or computed tomography findings.ResultsThe main feeding artery was the ipsilateral lingual artery (LA) in 15 of the 20 examined tumors and the contralateral LA in the other 5. Ten cancers had only one feeding artery, and multiple feeding arteries were detected in the remaining 10. Tumors >4 cm (n = 9), those with extension to the contralateral side (n = 13), and those with extension to TEMs (n = 15) were supplied by significantly larger numbers of feeding arteries compared to tumors without these features (P = 0.01, 0.049, and 0.02, respectively). The frequency of feeding from the contralateral LA was 64 % (9/14) and 17 % (1/6) in tumors with and without extension to the contralateral side, respectively. Feeding from a facial artery (FA) was not detected in tumors ≤4 cm, while 5 of the 9 (56 %) tumors >4 cm were supplied by a FA (P = 0.01).ConclusionA careful search for feeding arteries is required, especially in large tumors with extension to the contralateral side or to TEMs.

  1. A Finite Element Model for Mixed Porohyperelasticity with Transport, Swelling, and Growth

    Science.gov (United States)

    Armstrong, Michelle Hine; Buganza Tepole, Adrián; Kuhl, Ellen; Simon, Bruce R.; Vande Geest, Jonathan P.

    2016-01-01

    The purpose of this manuscript is to establish a unified theory of porohyperelasticity with transport and growth and to demonstrate the capability of this theory using a finite element model developed in MATLAB. We combine the theories of volumetric growth and mixed porohyperelasticity with transport and swelling (MPHETS) to derive a new method that models growth of biological soft tissues. The conservation equations and constitutive equations are developed for both solid-only growth and solid/fluid growth. An axisymmetric finite element framework is introduced for the new theory of growing MPHETS (GMPHETS). To illustrate the capabilities of this model, several example finite element test problems are considered using model geometry and material parameters based on experimental data from a porcine coronary artery. Multiple growth laws are considered, including time-driven, concentration-driven, and stress-driven growth. Time-driven growth is compared against an exact analytical solution to validate the model. For concentration-dependent growth, changing the diffusivity (representing a change in drug) fundamentally changes growth behavior. We further demonstrate that for stress-dependent, solid-only growth of an artery, growth of an MPHETS model results in a more uniform hoop stress than growth in a hyperelastic model for the same amount of growth time using the same growth law. This may have implications in the context of developing residual stresses in soft tissues under intraluminal pressure. To our knowledge, this manuscript provides the first full description of an MPHETS model with growth. The developed computational framework can be used in concert with novel in-vitro and in-vivo experimental approaches to identify the governing growth laws for various soft tissues. PMID:27078495

  2. Finite elements and approximation

    CERN Document Server

    Zienkiewicz, O C

    2006-01-01

    A powerful tool for the approximate solution of differential equations, the finite element is extensively used in industry and research. This book offers students of engineering and physics a comprehensive view of the principles involved, with numerous illustrative examples and exercises.Starting with continuum boundary value problems and the need for numerical discretization, the text examines finite difference methods, weighted residual methods in the context of continuous trial functions, and piecewise defined trial functions and the finite element method. Additional topics include higher o

  3. Difference in carotid artery elasticity in subjects with different brachial artery kinetic of vasodilatation.

    Science.gov (United States)

    Tripolino, C; Gnasso, A; Carallo, C; Scavelli, F B; Irace, C

    2016-08-01

    Increased carotid stiffness and impaired brachial artery flow-mediated dilatation (FMD) associate with cardiovascular events. We have previously reported three FMD patterns based on the time of maximal dilatation. The aim of the present study was to verify whether different FMD patterns associate with carotid artery stiffness. In all, 133 subjects were enrolled. All participants underwent complete clinical examination, blood sampling and ultrasound study. FMD was used as a measure of endothelial function. Based on the maximal brachial artery FMD, subjects were divided into Early dilators (peak FMD at 50 s), Late dilators (peak FMD over 50 s) and No dilators. Echo-Doppler evaluation of carotid arteries was performed in order to calculate elastic indexes (strain, β-stiffness index and distensibility). In all, 64 subjects were classified as Early FMD, 36 as Late FMD and 33 as No dilators. Age, gender and cardiovascular risk factors were comparable among three groups. Early FMD had higher values of strain compared with both Late and no Dilators (PFMD and No Dilators were detected. Our results demonstrate that common carotid artery elasticity indexes significantly differ among Early, Late and No dilators. Subjects with delayed or absent brachial artery dilatation have stiffer common carotid arteries compared with subjects with early dilatation. In conclusion, our research suggests that the assessment of the kinetics of FMD in a clinical setting might represent a useful screening tool to improve the cardiovascular risk stratification. PMID:26467820

  4. Proximity of arteries to the anterior ulna with changing flexion.

    Science.gov (United States)

    Enad, Jerome G; Douglas, Thomas J; Ruland, Robert T

    2015-04-01

    During surgery for elbow fracture, wires and screws crossing the elbow from posterior to anterior place the brachial and ulnar arteries at risk for inadvertent penetration. The authors' goal was to define the sagittal proximity of the brachial and ulnar arteries to the proximal ulna throughout an arc of elbow motion using dynamic fluoroscopy. The brachial artery was injected with barium in 10 fresh-frozen cadaveric elbows. Sagittal fluoroscopic images were obtained at elbow flexion angles of 0°, 30°, 60°, 90°, and 120°. Two measurements were obtained at each flexion angle: (1) the distance between the coronoid tip and the brachial artery and (2) the distance between the coronoid base and the ulnar artery. One-way analysis of variance was used to compare mean distances for each flexion angle within each measurement group. A coronal image identified the mediolateral course of the brachial artery. The distance from the coronoid tip to the brachial artery significantly increased with increasing flexion from 0° to 60° (P120° (P<.002). The brachial artery traversed lateral to the coronoid in 9 of 10 specimens. The brachial and ulnar arteries are located further from the coronoid with increasing elbow flexion to at least 60°, and the brachial artery is typically located lateral to the coronoid in the coronal plane. These measurements can be used as surgical guides to reduce the risk of arterial injury during olecranon fracture surgery. PMID:25901616

  5. Diagnosis and outcome of cervical artery dissection

    Directory of Open Access Journals (Sweden)

    Divjak Ivana

    2011-01-01

    Full Text Available Introduction. Spontaneous dissection of the cervical artery is a rare non-atherosclerotic vascular disease of unknown aetiology and unclear pathogenesis that may be a cause of ischemic stroke in young adults. Diagnosis. Precise diagnosis of dissection of the cervical artery - carotid or vertebral - is possible with cervical axial magnetic resonance imaging and magnetic resonance angiography. Treatment. The recommended treatment in the acute phase of cervical artery dissection is anticoagulant or antithrombotic therapy, aimed at preventing a primary or recurrent ischemic event. There have been as yet no results of randomized controlled studies comparing efficacy of both treatments. An ongoing randomized multicentre study is expected to provide answers about the effects of these treatments in cervical artery dissection. Outcome. Complete resolution of arterial abnormalities is achieved in around 46% of stenoses, 33% of occlusions, and 12% of dissecting aneurysms. Recurrent events. Recurrence of cerebral ischemia and cervical artery dissection seems to be rare, although some data suggest that early ischemic and late cervical artery dissection recurrences could be underestimated. Mortality and functional outcome. In comparison with other causes of stroke in young adults, the functional outcome of cervical artery dissection is good in contrast to its socio-professional effects, which may be unsatisfactory. The mortality rate of cervical artery dissection is low, although it may be underestimated since some patients with malignant infarction die before the diagnosis is established. Conclusion. Further research is warranted to improve our understanding of the underlying pathophysiology, to assess the long-term outcome, and ultimately to provide treatment and prevention strategies.

  6. Determination of the threshold of cardiac troponin I associated with an adverse postoperative outcome after cardiac surgery: a comparative study between coronary artery bypass graft, valve surgery, and combined cardiac surgery

    Science.gov (United States)

    Fellahi, Jean-Luc; Hedoire, François; Le Manach, Yannick; Monier, Emmanuel; Guillou, Louis; Riou, Bruno

    2007-01-01

    Introduction The objective of the present study was to compare postoperative cardiac troponin I (cTnI) release and the thresholds of cTnI that predict adverse outcome after elective coronary artery bypass graft (CABG), after valve surgery, and after combined cardiac surgery. Methods Six hundred and seventy-five adult patients undergoing conventional cardiac surgery with cardiopulmonary bypass were retrospectively analyzed. Patients in the CABG (n = 225) and valve surgery groups (n = 225) were selected after matching (age, sex) with those in the combined surgery group (n = 225). cTnI was measured preoperatively and 24 hours after the end of surgery. The main endpoint was a severe postoperative cardiac event (sustained ventricular arrhythmias requiring treatment, need for inotropic support or intraaortic balloon pump for at least 24 hours, postoperative myocardial infarction) and/or death. Data are presented as the median and the odds ratio (95% confidence interval). Results Postoperative cTnI levels were significantly different among the three groups (combined surgery, 11.0 (9.5–13.1) ng/ml versus CABG, 5.2 (4.7–5.7) ng/ml and valve surgery, 7.8 (7.6–8.0) ng/ml; P < 0.05). The thresholds of cTnI predicting severe cardiac event and/or death were also significantly different among the three groups (combined surgery, 11.8 (11.5–14.8) ng/ml versus CABG, 7.8 (6.7–8.8) ng/ml and valve surgery, 9.3 (8.0–14.0) ng/ml; P < 0.05). An elevated cTnI above the threshold in each group was significantly associated with a severe cardiac event and/or death (odds ratio, 4.33 (2.82–6.64)). Conclusion The magnitude of postoperative cTnI release is related to the type of cardiac surgical procedure. Different thresholds of cTnI must be considered according to the procedure type to predict early an adverse postoperative outcome. PMID:17888156

  7. Bilateral popliteal arterial dissection.

    Science.gov (United States)

    Chen, Po-Liang; Ko, Shih-Yu; Tan, Ken-Hing

    2012-01-01

    A clinical feature of bilateral popliteal arterial dissection without involving the descending aorta, bilateral iliac, as well as femoral arteries has never been reported in the past literature. We report a 56-year-old man with hypertension and coronary artery disease who presented to our emergency department with complaints of bilateral knee pain after long-distance walking. Physical examination was notable for elevated blood pressure, but there was no palpable pulsation over dorsalis pedis arteries on his feet. Laboratory evaluation revealed a d-dimer level of 35.2 mg/L (FEU) on the day of the test and 1.2 mg/L one and a half months ago (normal level, <0.55). These findings were suggestive of a recent-onset peripheral arterial occlusive disorder. Computed tomography of the aorta showed bilateral popliteal arterial dissection with arterial intimal flap. Abdominal aorta, bilateral iliac, and femoral arteries remained intact with only arteriosclerotic change. Minimally invasive endovascular stent grafting was then performed. The patient had an uneventful recovery. PMID:21106320

  8. Assessment Of Coronary Artery Aneurysms Using Transluminal Attenuation Gradient And Computational Modeling In Kawasaki Disease Patients

    Science.gov (United States)

    Grande Gutierrez, Noelia; Kahn, Andrew; Shirinsky, Olga; Gagarina, Nina; Lyskina, Galina; Fukazawa, Ryuji; Owaga, Shunichi; Burns, Jane; Marsden, Alison

    2015-11-01

    Kawasaki Disease (KD) can result in coronary artery aneurysms (CAA) in up to 25% of patients, putting them at risk of thrombus formation, myocardial infarction and sudden death. Clinical guidelines recommend CAA diameter >8 mm as the arbitrary criterion for initiating systemic anticoagulation. KD patient specific modeling and flow simulations suggest that hemodynamic data can predict regions at increased risk of thrombosis. Transluminal Attenuation Gradient (TAG) is determined from the change in radiological attenuation per vessel length and has been proposed as a non-invasive method for characterizing coronary stenosis from CT Angiography. We hypothesized that CAA abnormal flow could be quantified using TAG. We computed hemodynamics for patient specific coronary models using a stabilized finite element method, coupled numerically to a lumped parameter network to model the heart and vascular boundary conditions. TAG was quantified in the major coronary arteries. We compared TAG for aneurysmal and normal arteries and we analyzed TAG correlation with hemodynamic and geometrical parameters. Our results suggest that TAG may provide hemodynamic data not available from anatomy alone. TAG represents a possible extension to standard CTA that could help to better evaluate the risk of thrombus formation in KD.

  9. Efficient Induction of Finite State Automata

    OpenAIRE

    Collins, Matthew S.; Oliver, Jonathan

    2013-01-01

    This paper introduces a new algorithm for the induction if complex finite state automata from samples of behavior. The algorithm is based on information theoretic principles. The algorithm reduces the search space by many orders of magnitude over what was previously thought possible. We compare the algorithm with some existing induction techniques for finite state automata and show that the algorithm is much superior in both run time and quality of inductions.

  10. Holographic Brownian Motion at Finite Density

    CERN Document Server

    Banerjee, Pinaki

    2015-01-01

    We study holographic Brownian motion of a heavy charged particle at zero and small (but finite) temperature in presence of finite density. We are primarily interested in the dynamics at (near) zero temperature which is holographically described by motion of a fundamental string in an (near-) extremal RN black hole. We compute analytically the functional form of retarded Green's function and also compare that numerically at leading order in small frequency.

  11. Nonconforming finite element methods on quadrilateral meshes

    OpenAIRE

    Hu, Jun; Zhang, Shangyou

    2013-01-01

    It is well-known that it is comparatively difficult to design nonconforming finite elements on quadrilateral meshes by using Gauss-Legendre points on each edge of triangulations. One reason lies in that these degrees of freedom associated to these Gauss-Legendre points are not all linearly independent for usual expected polynomial spaces, which explains why only several lower order nonconforming quadrilateral finite elements can be found in literature. The present paper proposes two families ...

  12. Advanced finite element technologies

    CERN Document Server

    Wriggers, Peter

    2016-01-01

    The book presents an overview of the state of research of advanced finite element technologies. Besides the mathematical analysis, the finite element development and their engineering applications are shown to the reader. The authors give a survey of the methods and technologies concerning efficiency, robustness and performance aspects. The book covers the topics of mathematical foundations for variational approaches and the mathematical understanding of the analytical requirements of modern finite element methods. Special attention is paid to finite deformations, adaptive strategies, incompressible, isotropic or anisotropic material behavior and the mathematical and numerical treatment of the well-known locking phenomenon. Beyond that new results for the introduced approaches are presented especially for challenging nonlinear problems.

  13. Finite-Dimensional Calculus

    OpenAIRE

    Feinsilver, Philip; Schott, René

    2007-01-01

    We discuss topics related to finite-dimensional calculus in the context of finite-dimensional quantum mechanics. The truncated Heisenberg-Weyl algebra is called a TAA algebra after Tekin, Aydin, and Arik who formulated it in terms of orthofermions. It is shown how to use a matrix approach to implement analytic representations of the Heisenberg-Weyl algebra in univariate and multivariate settings. We provide examples for the univariate case. Krawtchouk polynomials are presented in detail, incl...

  14. Estudo comparativo de diferentes prescrições de braquetes pré-ajustados em modelos virtuais pelo Método de Elementos Finitos Comparative study of different pre-adjusted brackets prescriptions on virtual models, by Finite Elements Method

    Directory of Open Access Journals (Sweden)

    Murilo Fernando Neuppmann Feres

    2009-08-01

    Full Text Available OBJETIVOS: comparar os efeitos de diferentes prescrições de braquetes pré-ajustados na movimentação dentária dos dentes anterossuperiores, por meio da utilização do Método de Elementos Finitos (MEF. MÉTODOS: foi utilizado um modelo tridimensional composto por um incisivo central, um incisivo lateral e um canino, todos do hemiarco superior esquerdo. Esses elementos foram submetidos à atuação de vetores de força que simularam a ação dos pré-ajustes de angulação e torque dos braquetes das prescrições de Alexander, Andrews, Capelozza, MBT, Ricketts e Roth. Após a simulação, os dados referentes ao deslocamento espacial dos pontos incisais e apicais foram registrados de forma que o novo posicionamento admitido pelos longos eixos dentários e seus pontos constituintes fossem determinados. RESULTADOS: a maioria das prescrições se comportou similarmente em relação aos parâmetros avaliados. As diferenças significativas encontradas no estudo se referem ao incisivo lateral superior que continha o braquete com a prescrição de Ricketts, que apresentou uma menor inclinação vestibular de seu longo eixo. Além disso, o canino superior da mesma prescrição apresentou uma maior inclinação de seu longo eixo para mesial e uma maior inclinação vestibular de seu longo eixo em relação às outras. A avaliação qualitativa da movimentação do incisivo central superior indicou um maior deslocamento distal dos ápices radiculares para as prescrições cujos autores estipularam maiores valores de angulação (Andrews, Capelozza, Roth e Alexander, e um maior deslocamento vestibular da coroa para as prescrições que estipularam os maiores valores de torque para os incisivos centrais (Ricketts, MBT, Alexander e Roth.AIM: The aim of the present study was to compare the effects of different prescriptions on anterior superior tooth movement simulation through a Finite Element Method (FEM. METHODS: It was utilized a 3D model, which was

  15. Wall shear stress in intracranial aneurysms and adjacent arteries

    Institute of Scientific and Technical Information of China (English)

    Fuyu Wang; Bainan Xu; Zhenghui Sun; Chen Wu; Xiaojun Zhang

    2013-01-01

    Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries.

  16. Impaired arterial reactivity following cytomegalovirus infection in the immunosuppressed rat.

    OpenAIRE

    Eerdmans, P. H.; Persoons, M. C.; Debets, S. J.; Struijker Boudier, H. A.; Smits, J. F.; Bruggeman, C. A.; De Mey, J. G.

    1996-01-01

    1. Cytomegalovirus (CMV) is a major pathogen in immunocompromised individuals and may participate in the pathogenesis of atherosclerosis in the general population. We evaluated whether CMV-infection alters the function of arterial smooth muscle. 2. Blood pressure (BP) and arterial reactivity were recorded in immunosuppressed rats that had been infected with CMV (10(5) plaque forming units i.p.). Furthermore, the reactivity of isolated arteries was compared between CMV-infected rats and rats i...

  17. Comparison Study on the Performances of Finite Volume Method and Finite Difference Method

    OpenAIRE

    Bo Yu(Brookhaven National Lab); Dongjie Wang; Xinyu Zhang; Wang Li; Renwei Liu

    2013-01-01

    Vorticity-stream function method and MAC algorithm are adopted to systemically compare the finite volume method (FVM) and finite difference method (FDM) in this paper. Two typical problems—lid-driven flow and natural convection flow in a square cavity—are taken as examples to compare and analyze the calculation performances of FVM and FDM with variant mesh densities, discrete forms, and treatments of boundary condition. It is indicated that FVM is superior to FDM from the pe...

  18. Hemodynamic analysis in an idealized artery tree: differences in wall shear stress between Newtonian and non-Newtonian blood models.

    Directory of Open Access Journals (Sweden)

    Jared C Weddell

    Full Text Available Development of many conditions and disorders, such as atherosclerosis and stroke, are dependent upon hemodynamic forces. To accurately predict and prevent these conditions and disorders hemodynamic forces must be properly mapped. Here we compare a shear-rate dependent fluid (SDF constitutive model, based on the works by Yasuda et al in 1981, against a Newtonian model of blood. We verify our stabilized finite element numerical method with the benchmark lid-driven cavity flow problem. Numerical simulations show that the Newtonian model gives similar velocity profiles in the 2-dimensional cavity given different height and width dimensions, given the same Reynolds number. Conversely, the SDF model gave dissimilar velocity profiles, differing from the Newtonian velocity profiles by up to 25% in velocity magnitudes. This difference can affect estimation in platelet distribution within blood vessels or magnetic nanoparticle delivery. Wall shear stress (WSS is an important quantity involved in vascular remodeling through integrin and adhesion molecule mechanotransduction. The SDF model gave a 7.3-fold greater WSS than the Newtonian model at the top of the 3-dimensional cavity. The SDF model gave a 37.7-fold greater WSS than the Newtonian model at artery walls located immediately after bifurcations in the idealized femoral artery tree. The pressure drop across arteries reveals arterial sections highly resistive to flow which correlates with stenosis formation. Numerical simulations give the pressure drop across the idealized femoral artery tree with the SDF model which is approximately 2.3-fold higher than with the Newtonian model. In atherosclerotic lesion models, the SDF model gives over 1 Pa higher WSS than the Newtonian model, a difference correlated with over twice as many adherent monocytes to endothelial cells from the Newtonian model compared to the SDF model.

  19. Hemodynamic analysis in an idealized artery tree: differences in wall shear stress between Newtonian and non-Newtonian blood models.

    Science.gov (United States)

    Weddell, Jared C; Kwack, JaeHyuk; Imoukhuede, P I; Masud, Arif

    2015-01-01

    Development of many conditions and disorders, such as atherosclerosis and stroke, are dependent upon hemodynamic forces. To accurately predict and prevent these conditions and disorders hemodynamic forces must be properly mapped. Here we compare a shear-rate dependent fluid (SDF) constitutive model, based on the works by Yasuda et al in 1981, against a Newtonian model of blood. We verify our stabilized finite element numerical method with the benchmark lid-driven cavity flow problem. Numerical simulations show that the Newtonian model gives similar velocity profiles in the 2-dimensional cavity given different height and width dimensions, given the same Reynolds number. Conversely, the SDF model gave dissimilar velocity profiles, differing from the Newtonian velocity profiles by up to 25% in velocity magnitudes. This difference can affect estimation in platelet distribution within blood vessels or magnetic nanoparticle delivery. Wall shear stress (WSS) is an important quantity involved in vascular remodeling through integrin and adhesion molecule mechanotransduction. The SDF model gave a 7.3-fold greater WSS than the Newtonian model at the top of the 3-dimensional cavity. The SDF model gave a 37.7-fold greater WSS than the Newtonian model at artery walls located immediately after bifurcations in the idealized femoral artery tree. The pressure drop across arteries reveals arterial sections highly resistive to flow which correlates with stenosis formation. Numerical simulations give the pressure drop across the idealized femoral artery tree with the SDF model which is approximately 2.3-fold higher than with the Newtonian model. In atherosclerotic lesion models, the SDF model gives over 1 Pa higher WSS than the Newtonian model, a difference correlated with over twice as many adherent monocytes to endothelial cells from the Newtonian model compared to the SDF model. PMID:25897758

  20. 犬冠状动脉和脑动脉多巴胺受体亚型对比研究%Comparative studies on the characteristics of dopamine receptors in canines' coronary and cerebral arteries

    Institute of Scientific and Technical Information of China (English)

    王毅; 朱琳; 郑丽丽; 赵荣瑞

    2001-01-01

    Aim:To study the (DA) receptor subtypes and functional significance in canine coronary and cerebral arteries.Methods:Vascular ring technique was used for determining vasorelaxing response to fenoldopam and PBDA in canine coronary and cerebral arteries.Results:①DA1 receptors were distributed in the coronary and cerebral arteries,however,a great variation in their functional potency existed;②DA2 receptors were only present in the cerebral artery. Conclusion:To clarify the heterogeneity in subtype and responsiveness of DA receptors in the coronary and cerebral arteries may help to evaluate the physiological signifiance of DA receptors.%目的:对比分析犬冠状动脉和脑动脉多巴胺(DA)受体亚型类别与反应特性。方法:利用离体血管微量生物反应检测技术,测定多巴胺1(DA1)受体激动剂非诺多泮(Fenoldopam,FODA)和多巴胺2(DA2)受体激动剂propylbutyl-dopamine(PBDA)对冠状动脉和脑动脉血管环的舒张反应。结果:①冠状动脉和脑动脉均有DA1受体分布,但其分布密度存在明显差别;②脑动脉内既有DA1受体又有DA2受体分布;③用6-羟多巴胺(6-OHDA)处理后的实验进一步证实脑动脉存在有DA2受体。结论:冠状动脉和脑动脉DA受体亚型存在明显的异质性,阐明这种异质性将有助于了解多巴胺受体对冠脉循环和脑循环的不同生理反应。

  1. Coronary Artery Bypass

    Directory of Open Access Journals (Sweden)

    Kadri Ceberut

    2011-01-01

    Full Text Available Ancient schwannoma is a rare variant of neural tumors though rarely seen in the thorax. The combination with coronary artery diseases is also rare. Here we describe a 66 year-old male who had undergone one-stage combined surgery for thoracic ancient schwannomas removal and coronary artery disease. The masses were, respectively, 13 cm in the middle mediastinum and 5 cm in diameter originating from the intercostal nerve. The tumors were successfully removed using sternotomy, and then a coronary artery bypass grafting was performed. Here we discuss this rare tumor in relation to the relevant literature.

  2. A Finite Element Framework for Some Mimetic Finite Difference Discretizations

    OpenAIRE

    Rodrigo, Carmen; Gaspar, Francisco; Hu, Xiaozhe; Zikatanov, Ludmil

    2015-01-01

    In this work we derive equivalence relations between mimetic finite difference schemes on simplicial grids and modified N\\'ed\\'elec-Raviart-Thomas finite element methods for model problems in $\\mathbf{H}(\\operatorname{\\mathbf{curl}})$ and $H(\\operatorname{div})$. This provides a simple and transparent way to analyze such mimetic finite difference discretizations using the well-known results from finite element theory. The finite element framework that we develop is also crucial for the design...

  3. Finite Blaschke products: a survey

    OpenAIRE

    Garcia, Stephan Ramon; Mashreghi, Javad; Ross, William T.

    2015-01-01

    A finite Blaschke product is a product of finitely many automorphisms of the unit disk. This brief survey covers some of the main topics in the area, including characterizations of finite Blaschke products, approximation theorems, derivatives and residues of finite Blaschke products, geometric localization of zeros, and selected other topics.

  4. Elastomeric PGS scaffolds in arterial tissue engineering.

    Science.gov (United States)

    Lee, Kee-Won; Wang, Yadong

    2011-01-01

    Cardiovascular disease is one of the leading cause of mortality in the US and especially, coronary artery disease increases with an aging population and increasing obesity. Currently, bypass surgery using autologous vessels, allografts, and synthetic grafts are known as a commonly used for arterial substitutes. However, these grafts have limited applications when an inner diameter of arteries is less than 6 mm due to low availability, thrombotic complications, compliance mismatch, and late intimal hyperplasia. To overcome these limitations, tissue engineering has been successfully applied as a promising alternative to develop small-diameter arterial constructs that are nonthrombogenic, robust, and compliant. Several previous studies have developed small-diameter arterial constructs with tri-lamellar structure, excellent mechanical properties and burst pressure comparable to native arteries. While high tensile strength and burst pressure by increasing collagen production from a rigid material or cell sheet scaffold, these constructs still had low elastin production and compliance, which is a major problem to cause graft failure after implantation. Considering these issues, we hypothesized that an elastometric biomaterial combined with mechanical conditioning would provide elasticity and conduct mechanical signals more efficiently to vascular cells, which increase extracellular matrix production and support cellular orientation. The objective of this report is to introduce a fabrication technique of porous tubular scaffolds and a dynamic mechanical conditioning for applying them to arterial tissue engineering. We used a biodegradable elastomer, poly (glycerol sebacate) (PGS) for fabricating porous tubular scaffolds from the salt fusion method. Adult primary baboon smooth muscle cells (SMCs) were seeded on the lumen of scaffolds, which cultured in our designed pulsatile flow bioreactor for 3 weeks. PGS scaffolds had consistent thickness and randomly distributed macro

  5. 症状性颅、颈部动脉狭窄在3.0T上的MRA与DSA比较研究%Evaluation of 3.0 Tesla MRA in diagnosing symptomatic craniocervicai artery stenosis: a comparative study with DSA

    Institute of Scientific and Technical Information of China (English)

    李梅; 李明华; 王建波; 王珏; 方淳; 乔瑞华

    2009-01-01

    目的 前瞻性分析3.0T应用SENSE技术的高分辨率对比增强容积扫描MRA(CEMRA)和3DTOFMRA在临床疑有颅、颈部动脉狭窄性病变患者中的应用价值.方法 46例临床怀疑颅、颈部动脉狭窄的患者接受头颅MRI平扫、头颅3DTOFMRA和颈部CEMRA检查.动脉狭窄的程度与DSA检查结果进行相关性比较.结果 MRA显示各段颅、颈部动脉狭窄的不同程度和DSA检查显著相关(Rs=0.97,P<0.01).以DSA结果为金标准,狭窄程度超过50%者MRA诊断灵敏度为100%,特异度为99.4%、准确率为99.4%.结论 3.0T的3DTOFMRA和高分辨率CEMRA检查能可靠和有效地评价颅、颈部动脉狭窄性病变,可作为DSA术前必要的检查技术,或可替代传统DSA诊断性检查.%Objective To prospectively evaluate 3D time-of-flight magnetic resonance angiography (3DTOF MRA) and high resolution contrast enhanced volume scan magnetic resonance angiography (CEMRA) with sensitivity encoding in diagnosing craniocervical artery stenosis. Methods Forty-six patients suspected with craniocervical artery diseases underwent MRI, 3DTOF MRA of the head and also CEMRA of the neck. The images of MRA were reconstructed with MIP and VR. The degree of arterial stenosis demonstrated on MRA was compared with that showed on digital subtraction angiography(DSA), and the data were analyzed with Spearman rank correlation coefficient (Rs). Results Excellent correlation in determining the degree of craniocervical artery stenosis existed between MRA and DSA (Rs = 0.97). With DSA as a golden standard, the sensitivity, specificity and accuracy of MRA in detecting over 50% arterial stenosis were 100%, 99.4% and 99.4% respectively. Conclusion 3DTOF MRA and CEMRA with sensitivity encoding at 3.0T are reliable and effective examinations for evaluating craniocervical artery disease. These techniques can be used as the necessary exams before DSA and can even substitute for the conventional DSA in some instances.

  6. Peripheral Arterial Disease

    Science.gov (United States)

    Peripheral arterial disease (PAD) happens when there is a narrowing of the blood vessels outside of your heart. The cause of ... smoking. Other risk factors include older age and diseases like diabetes, high blood cholesterol, high blood pressure, ...

  7. Coronary artery spasm

    Science.gov (United States)

    ... blocker or a long-acting nitrate long-term. Beta-blockers are another type of medicine that is used with other coronary artery problems. However, beta-blockers may make this problem worse. They should be ...

  8. Pulmonary Arterial Hypertension

    Science.gov (United States)

    Pulmonary Arterial Hypertension What Is Pulmonary Hypertension? To understand pulmonary hypertension (PH) it helps to understand how blood ows throughout your body. While the heart is one organ, it ...

  9. Carotid artery disease

    Science.gov (United States)

    ... you have had a stroke or TIA, a nervous system (neurological) exam will show other problems. You may also have the following tests: Blood cholesterol and triglycerides test Blood sugar (glucose) test Ultrasound of the carotid arteries ( carotid ...

  10. Finite element analysis

    CERN Document Server

    2010-01-01

    Finite element analysis is an engineering method for the numerical analysis of complex structures. This book provides a bird's eye view on this very broad matter through 27 original and innovative research studies exhibiting various investigation directions. Through its chapters the reader will have access to works related to Biomedical Engineering, Materials Engineering, Process Analysis and Civil Engineering. The text is addressed not only to researchers, but also to professional engineers, engineering lecturers and students seeking to gain a better understanding of where Finite Element Analysis stands today.

  11. The finite Bruck Loops

    CERN Document Server

    Baumeister, Barbara

    2009-01-01

    We continue the work by Aschbacher, Kinyon and Phillips [AKP] as well as of Glauberman [Glaub1,2] by describing the structure of the finite Bruck loops. We show essentially that a finite Bruck loop $X$ is the direct product of a Bruck loop of odd order with either a soluble Bruck loop of 2-power order or a product of loops related to the groups $PSL_2(q)$, $q= 9$ or $q \\geq 5$ a Fermat prime. The latter possibillity does occur as is shown in [Nag1, BS]. As corollaries we obtain versions of Sylow's, Lagrange's and Hall's Theorems for loops.

  12. Breast arterial calcification on mammogram: correlation with carotid arterial atherosclerosis on ultrasonogram

    International Nuclear Information System (INIS)

    To investigate the incidence of breast arterial calcification in Korean women, and to determine its association with systemic diseases and carotid arterial atherosclerosis. One thousand seven hundred and thirteen female subjects who underwent mammography at a health care center between May 1999 and May 2000 were included in this study. Of the total, 172 were found to have breast arterial calcification, and were classified according to age. The coincidence of hypertension, diabetes mellitus and hyperlipidemia was examined in both the subject group and the control group selected on the same age basis. To investigate the presence and degree of carotid atherosclerosis, sonographic imaging was performed and the findings were compared between the two groups. The incidence of breast arterial calcification showed statistically significant differences according to age, with a higher incidence in older patients (p<0.05). However, there was no statistical difference in the incidence of hypertension, hyperlipidemia, and diabetes mellitus between groups. Carotid atherosclerosis was subjects more prevalent among subjects than in the control group (p<0.05), though there was no statistically significant difference in the degree of luminal stenosis. The most common pathologic cause of breast arterial calcification is arteriosclerosis. Breast arterial calcification is demonstrated at mammography, along with other clinical risk factors for atherosclerosis or coincidental neurologic symptoms. We stress that further evaluation of the carotid artery is necessary

  13. Breast arterial calcification on mammogram: correlation with carotid arterial atherosclerosis on ultrasonogram

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Nam Ju; Suh, Jung Ho [School of Medicine, Ajou Univ., Suwon (Korea, Republic of); Kim, Ji Hyung [College of Medicine, KonYang Univ., Nonsan (Korea, Republic of)

    2002-01-01

    To investigate the incidence of breast arterial calcification in Korean women, and to determine its association with systemic diseases and carotid arterial atherosclerosis. One thousand seven hundred and thirteen female subjects who underwent mammography at a health care center between May 1999 and May 2000 were included in this study. Of the total, 172 were found to have breast arterial calcification, and were classified according to age. The coincidence of hypertension, diabetes mellitus and hyperlipidemia was examined in both the subject group and the control group selected on the same age basis. To investigate the presence and degree of carotid atherosclerosis, sonographic imaging was performed and the findings were compared between the two groups. The incidence of breast arterial calcification showed statistically significant differences according to age, with a higher incidence in older patients (p<0.05). However, there was no statistical difference in the incidence of hypertension, hyperlipidemia, and diabetes mellitus between groups. Carotid atherosclerosis was subjects more prevalent among subjects than in the control group (p<0.05), though there was no statistically significant difference in the degree of luminal stenosis. The most common pathologic cause of breast arterial calcification is arteriosclerosis. Breast arterial calcification is demonstrated at mammography, along with other clinical risk factors for atherosclerosis or coincidental neurologic symptoms. We stress that further evaluation of the carotid artery is necessary.

  14. MORPHOLOGICAL STUDY OF THE BASILAR ARTERY IN ADULT HUMAN CADAVERS

    Directory of Open Access Journals (Sweden)

    Harish A. Wankhede

    2014-09-01

    Full Text Available Background: The basilar artery is the large median and major artery of the posterior circulation of the brain. Many variations are seen in the basilar artery, majority of them in position, origin and shape of the artery. Many authors have documented various anomalies as well as differences of the anatomy in this area in the Indian population as compared to the Western literature. Context and purpose of study: Many studies are available on the anterior circulation of the brain i.e. on vessels of the circle of Willis but studies on the posterior circulation are very few. And such studies so far had been done mostly in the American and European races and are mostly based on imaging techniques. Studies in the Indian population have been few. Hence the present study is concentrated on the morphological study of the basilar artery of human adult brain, to show the frequency and type of variations in the morphology of the basilar artery. Results: The basilar artery most commonly takes origin from the vertebral artery where left vertebral artery is greater in size than the right vertebral artery (72.5%. Level of formation of the basilar artery is most commonly observed at the ponto-medullary junction (62.5%. Length of the basilar artery varied from minimum 2.4cm to maximum 3.6cm. More commonly artery lies in the range of 2.6-3.0cm (57.5%. Diameter of the basilar artery at origin ranges from 3.2-4.2mm, at mid level from 3-4mm and at termination 3.1-4mm. Level of termination of the basilar artery is more commonly at the mid brain-pons junction (50%. Most of the basilar arteries are of straight type (55% and next common is bent or curved type (37.5%. Fenestration of 4mm is seen in proximal part of the one basilar artery (2.5%. Conclusion: Variations of the basilar artery are common. Neurosurgical importance of this study lies during the exposure of the region for different purposes. Knowledge of the vascular variations will increase the success of the

  15. 晚期直肠癌动脉化疗灌注术与全身化疗对比分析%Comparative analysis of efficacy between arterial infusion chemotherapy and systemic chemotherapy in advanced rectal cancer

    Institute of Scientific and Technical Information of China (English)

    杨光华

    2011-01-01

    目的 对直肠癌动脉化疗灌注疗效进行分析.方法 将14例Dukes'D期直肠癌行动脉灌注化疗的设为观察组,将同时期24例晚期直肠癌行单纯化疗的设为对照组进行对比研究.结果 观察组总有效率为100%(14/14),对照组总有效率为70.83%(17/24),有统计学意义(P<0.05).结论 Dukes'D期直肠癌患者动脉化疗灌注术及栓塞术比单纯化疗短期疗效明显提高.%Objective To analyze the efficacy of arterial infusion chemotherapy in advanced rectal cancer. Methods Totally 14 patients in Dukes' D period rectal cancer were selected for experimental group and 24 patients with advanced rectal cancer in the same period were selected for control group.The experimental group was treated by arterial infusion chemotherapy and the control group was treated with systemic chemotherapy. Results The total effective rate of the experimental group and the control group were respectively 14/14 (100%), 17/24 (70.83%). The differences between the two groups had statistically significant ( P < 0.05 ). Conclusions The efficacy of arterial infusion chemotherapy was obviously superior to systemic chemotherapy in patients with Dukes' D period rectal cancer.

  16. A multigrid solution method for mixed hybrid finite elements

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, W. [Universitaet Augsburg (Germany)

    1996-12-31

    We consider the multigrid solution of linear equations arising within the discretization of elliptic second order boundary value problems of the form by mixed hybrid finite elements. Using the equivalence of mixed hybrid finite elements and non-conforming nodal finite elements, we construct a multigrid scheme for the corresponding non-conforming finite elements, and, by this equivalence, for the mixed hybrid finite elements, following guidelines from Arbogast/Chen. For a rectangular triangulation of the computational domain, this non-conforming schemes are the so-called nodal finite elements. We explicitly construct prolongation and restriction operators for this type of non-conforming finite elements. We discuss the use of plain multigrid and the multilevel-preconditioned cg-method and compare their efficiency in numerical tests.

  17. Adaptive finite difference for seismic wavefield modelling in acoustic media.

    Science.gov (United States)

    Yao, Gang; Wu, Di; Debens, Henry Alexander

    2016-01-01

    Efficient numerical seismic wavefield modelling is a key component of modern seismic imaging techniques, such as reverse-time migration and full-waveform inversion. Finite difference methods are perhaps the most widely used numerical approach for forward modelling, and here we introduce a novel scheme for implementing finite difference by introducing a time-to-space wavelet mapping. Finite difference coefficients are then computed by minimising the difference between the spatial derivatives of the mapped wavelet and the finite difference operator over all propagation angles. Since the coefficients vary adaptively with different velocities and source wavelet bandwidths, the method is capable to maximise the accuracy of the finite difference operator. Numerical examples demonstrate that this method is superior to standard finite difference methods, while comparable to Zhang's optimised finite difference scheme. PMID:27491333

  18. Arterial stiffness, hypertension, and rational use of nebivolol

    Directory of Open Access Journals (Sweden)

    Enrico Agabiti-Rosei

    2009-05-01

    Full Text Available Enrico Agabiti-Rosei, Enzo Porteri, Damiano RizzoniClinica Medica, Department of Medical and Surgical Sciences, University of Brescia, ItalyAbstract: Arterial stiffness plays a key role in the pathophysiology of the cardiovascular system. Some indices of arterial stiffness (pulse wave velocity, augmentation index, characteristics of central blood pressure waveform may be presently calculated and evaluated in the clinical setting. Age and blood pressure are the two major clinical determinants of increased arterial stiffness, while molecular determinants of arterial stiffness are related to fibrotic components of the extracellular matrix, mainly elastin, collagen and fibronectin. Increased arterial stiffness has been consistently observed in conditions such as hypertension, dyslipidemia and diabetes. Arterial stiffness evaluated by means of carotid-femoral pulse wave velocity yielded prognostic significance beyond and above traditional risk factors. A more favorable effect of calcium channel blockers, diuretics and ACE inhibitors compared with β-blockers on indices of arterial stiffness was observed in several studies. It is conceivable that newer β-blockers with additional vasodilating properties, such as nebivolol, which has favorable effects on carbohydrate and lipid metabolism, as well as on endothelial function and on oxidative stress, may have favorable effects on arterial stiffness, compared with atenolol. In fact, in recent studies, nebivolol was demonstrated to improve artery stiffness to a greater extent than older β-blockers. Because endothelial dysfunction and increased arterial stiffness play an important role in the early atherosclerotic processes and are associated with poor outcomes and increased mortality, independently of blood pressure, the ability of nebivolol to enhance release of endothelium-derived nitric oxide, and consequently improve endothelial function and arterial stiffness, may have significant clinical

  19. Superselective pseudo-continuous arterial spin labeling angiography

    International Nuclear Information System (INIS)

    Highlights: • Superselective arterial spin labeling was capable of acquiring angiograms of individually selected arteries. • Image quality was similar compared with a routinely used time-of-flight angiography. • Superselective arterial spin labeling was utilized in patients with arterio-venous malformations and made it possible to visualize individual feeding vessels in a complete non-invasive way - Abstract: Purpose: To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous arterial spin labeling (ASL) for the morphologic assessment of intracranial arteries when compared to a clinically used time-of-flight (TOF) MRA. Materials and methods: Three sets of selective ASL angiographies (right and left internal carotid artery, basilar artery) as well as one TOF data set were obtained from each of the five volunteers included in this study on a clinical 1.5T system. The depiction of arterial segments as well as their delineation was evaluated and independently analyzed by two radiologists. Additionally, the ASL angiography approach was performed in two patients suffering from arterio-venous malformations (AVM) in order to illustrate potential applications in a clinical setting. Results: In both angiography techniques, intracranial arteries and their segments (distal branches up to A5 segments of the anterior cerebral arteries, M8 segments of the middle cerebral arteries, and P5 segments of the posterior cerebral arteries) were continuously depicted with excellent inter-reader agreement (κ > 0.81). In AVM patients, reconstructed images of the TOF angiography presented similar information about the size and shape of the AVM as did superselective ASL angiography. In addition, the acquired ASL angiograms of selected vessels allowed assessing the blood supply of individually labeled arteries to the AVM which could also be confirmed by digital subtraction angiography

  20. Superselective pseudo-continuous arterial spin labeling angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jensen-Kondering, Ulf [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Lindner, Thomas, E-mail: thomas.lindner@uksh.de [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Osch, Matthias J.P. van [C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden (Netherlands); Rohr, Axel; Jansen, Olav [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Helle, Michael [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Now with Philips GmbH Innovative Technologies, Research Laboratories, Hamburg (Germany)

    2015-09-15

    Highlights: • Superselective arterial spin labeling was capable of acquiring angiograms of individually selected arteries. • Image quality was similar compared with a routinely used time-of-flight angiography. • Superselective arterial spin labeling was utilized in patients with arterio-venous malformations and made it possible to visualize individual feeding vessels in a complete non-invasive way - Abstract: Purpose: To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous arterial spin labeling (ASL) for the morphologic assessment of intracranial arteries when compared to a clinically used time-of-flight (TOF) MRA. Materials and methods: Three sets of selective ASL angiographies (right and left internal carotid artery, basilar artery) as well as one TOF data set were obtained from each of the five volunteers included in this study on a clinical 1.5T system. The depiction of arterial segments as well as their delineation was evaluated and independently analyzed by two radiologists. Additionally, the ASL angiography approach was performed in two patients suffering from arterio-venous malformations (AVM) in order to illustrate potential applications in a clinical setting. Results: In both angiography techniques, intracranial arteries and their segments (distal branches up to A5 segments of the anterior cerebral arteries, M8 segments of the middle cerebral arteries, and P5 segments of the posterior cerebral arteries) were continuously depicted with excellent inter-reader agreement (κ > 0.81). In AVM patients, reconstructed images of the TOF angiography presented similar information about the size and shape of the AVM as did superselective ASL angiography. In addition, the acquired ASL angiograms of selected vessels allowed assessing the blood supply of individually labeled arteries to the AVM which could also be confirmed by digital subtraction angiography

  1. Finite Complements in English

    Institute of Scientific and Technical Information of China (English)

    Ronald W. Langacker

    2008-01-01

    This paper explores the conceptual basis of finite complimentation in English.It first considem the distinguishing property of a finite clause,namely grounding,effeeted by tense and the modals.Notions crucial for clausal grounding--including a reality conception and the striving for control at the effective and epistemic levelsalso figure in the semantic import of eomplementation.An essential feature of complement constructions is the involvement of multiple conceptualizers,each with their own conception of reality.The different types of complement and their grammatical markings can be characterized on this basis.Finite complements differ from other types by virtue of expressing an autonomous proposition capable of being apprehended by multiple conceptualizers,each from their own vantage point.Acognitive model representing phases in the striving for epistemic control provides a partial basis for the semantic description of predicates taking finite complements.The same model supports the description of both personal and impersonal complement constructions.

  2. Finite-dimensional utilities

    OpenAIRE

    Yutaka Nakamura

    2000-01-01

    Sufficient axioms are identified for the existence of a finite- dimensional quasilinear utility function whose lexicographically ordered vectors preserve a decision maker's preference order on a mixture set ${\\cal M}$. It is shown that those axioms are also necessary for the linear lexicographic representation when the underlying set ${\\cal M}$ is a mixture space.

  3. Finite fields and cryptology

    Directory of Open Access Journals (Sweden)

    Ennio Cortellini

    2003-10-01

    Full Text Available The problem of a computationally feasible method of finding the discrete logarithm in a (large finite field is discussed, presenting the main algorithms in this direction. Some cryptographic schemes based on the discrete logarithm are presented. Finally, the theory of linear recurring sequences is outlined, in relation to its applications in cryptology.

  4. Finite fields and cryptology

    OpenAIRE

    Ennio Cortellini

    2003-01-01

    The problem of a computationally feasible method of finding the discrete logarithm in a (large) finite field is discussed, presenting the main algorithms in this direction. Some cryptographic schemes based on the discrete logarithm are presented. Finally, the theory of linear recurring sequences is outlined, in relation to its applications in cryptology.

  5. Inside finite elements

    CERN Document Server

    Weiser, Martin

    2016-01-01

    All relevant implementation aspects of finite element methods are discussed in this book. The focus is on algorithms and data structures as well as on their concrete implementation. Theory is covered as far as it gives insight into the construction of algorithms. Throughout the exercises a complete FE-solver for scalar 2D problems will be implemented in Matlab/Octave.

  6. Hepatocellular carcinoma with extensive hepatic artery injury: transcatheter arterial chemoembolization through collaterals after coil embolizatoin of gastric arteries

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gab Choul; Yoon, Hyun Ki; Hwang, Jae Cheol; Lee, Duck Hee; Song, Ho Young; Suh, Dong Jin; Lee, Yung Sang; Chung, Young Hwa; Sung, Gyu Bo [Ulsan Univ. College of Medicine, Seoul (Korea, Republic of); Ko, Ki Young [Catholic Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-09-01

    To evaluate the efficacy and safety of transcatheter arterial chemoembolization(TACE) after coil embolization of the gastroduodenal artery in hepatocellular carcinoma cases with multiple collateral arteries caused by proper hepatic artery injury. Between March 1997 and November 1998, a prospective trial of transcatheter arterial chemoembolization (TACE) was performed through collaterals from the gastroduodenal artery of 31 hepatocellular carcinoma patients with extensive proper hepatic artery injury due to repeated TACE. Among this number, 16 (group A) underwent TACE after coil embolization of the right gastric and gastroduodenal artery. The other 15 patients (group B) underwent TACE without coil embolization. The two groups had the same TNM stage and Clild-Pugh status. During the follow-up period, group A underwent additional TACE 3.3 times, and group B 2.8 times. The therapeutic effect of TACE was evaluated with computed tomography and by measuring alpha-fetoprotein levels. Complications were evaluated by means of gastrofibroscopy, laboratory data, and evaluation of the patients' clinical symptoms. The results obtained after six months and one year were compared within and between each group. At six months follow-up, CT findings had improved or were unchanged in 11 patients(69 %) in group A, and four patients(27 %) in group B(p = 0.032). In ten patients in each group, the level of alpha-fetoprotein was above 200 ng/ml. Its level was decreased in five patients(50 %) and three patients(30 %), respectively. The six-month survival rate was 81 % (13/16) in group A and 67% (10/15) in group B (p 0.43), while the one-year survival figures for these two groups were 50 % (8/16) and 20 % (3/15), respectively(p = 0.135). In group A, the CT findings were steady in five out of eight patients(63 %), while in groupB, CT findings showed that tumors with increased alpha-fetoprotein levels had increased in size and/or number. In group A, it was found that in two (33 %) of six

  7. Nonlinear, finite deformation, finite element analysis

    Science.gov (United States)

    Nguyen, Nhung; Waas, Anthony M.

    2016-06-01

    The roles of the consistent Jacobian matrix and the material tangent moduli, which are used in nonlinear incremental finite deformation mechanics problems solved using the finite element method, are emphasized in this paper, and demonstrated using the commercial software ABAQUS standard. In doing so, the necessity for correctly employing user material subroutines to solve nonlinear problems involving large deformation and/or large rotation is clarified. Starting with the rate form of the principle of virtual work, the derivations of the material tangent moduli, the consistent Jacobian matrix, the stress/strain measures, and the objective stress rates are discussed and clarified. The difference between the consistent Jacobian matrix (which, in the ABAQUS UMAT user material subroutine is referred to as DDSDDE) and the material tangent moduli ( C e ) needed for the stress update is pointed out and emphasized in this paper. While the former is derived based on the Jaumann rate of the Kirchhoff stress, the latter is derived using the Jaumann rate of the Cauchy stress. Understanding the difference between these two objective stress rates is crucial for correctly implementing a constitutive model, especially a rate form constitutive relation, and for ensuring fast convergence. Specifically, the implementation requires the stresses to be updated correctly. For this, the strains must be computed directly from the deformation gradient and corresponding strain measure (for a total form model). Alternatively, the material tangent moduli derived from the corresponding Jaumann rate of the Cauchy stress of the constitutive relation (for a rate form model) should be used. Given that this requirement is satisfied, the consistent Jacobian matrix only influences the rate of convergence. Its derivation should be based on the Jaumann rate of the Kirchhoff stress to ensure fast convergence; however, the use of a different objective stress rate may also be possible. The error associated

  8. Investigation Of Interaction Between Nitinol Stent And A Vascular Plaque Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Recep Güneş

    2012-06-01

    Full Text Available In this study, the interaction between the Nitinol stent and the artery with plaque was investigated using finite element method. The occurring pressure values during the cardiac contraction (systolic and loosening (diastolic were applied as loading to the modeled system with Nitinol stent. In the light of the stress values, the suitability of the Nitinol stent in an artery with plaque was investigated. In the analysis, Nitinol stent was assumed to be shape memory alloy, and artery and plaque were assumed to behave linearly elastic. As a result, the stress and deformations in the plaque and artery due to the interference of Nitinol stent were discussed and concluded that the structure of artery with plaque can be expanded in accordance with Nitinol stent.

  9. One-pion exchange potential at finite temperature and finite density

    International Nuclear Information System (INIS)

    By means of the real-time temperature Green function method, we extend the one-pion exchange potential (OPEP) with pseudovector coupling and pseudoscalar coupling to finite density and finite temperature. After summing all the bubble diagrams of the exchange of the pion, we find that the density effects on the effective mass of pion and OPEP are considerable at low temperature. The density effects and the temperature effects of OPEP are compared. (author)

  10. Fifty-eight cases of ocular ischemic diseases caused by carotid artery stenosis

    Institute of Scientific and Technical Information of China (English)

    LUO Rong-jiang; LIU Shao-rui; LI Xiao-min; ZHUO Ye-hong; TIAN Zhen

    2010-01-01

    Background The blood supply to the eye comes from the retinal central vascular system of the ophthalmic artery and the ciliary vascular system. The ophthalmic artery stems from the ipsilateral internal carotid artery. If occlusion or stenosis occurs in the carotid artery, the blood perfusion to the ophthalmic artery becomes insufficient, leading to signs and symptoms of anterior and posterior ocular ischemia. The objective of this study was to evaluate the clinical characteristics and risk factors of ocular ischemic diseases caused by carotid artery stenosis.Methods This study was a retrospective review of 145 patients with carotid artery stenosis. Fifty-eight patients who had symptoms of ocular ischemic disease caused by carotid artery stenosis formed group A and the other 87 patients who only had carotid artery stenosis formed group B. We analyzed the causes and course of disease, and relative risk factors,by comparing the two groups.Results The degree of carotid artery stenosis in group A was higher than that in group B. And group A had a greater decrease of ophthalmic artery flow. Male, hypertension, hyperlipidemia, and smoking were significantly related to carotid artery stenosis. Amaurosis fugax was the most common ocular symptom in group A. The ocular ischemic diseases mainly included ischemic optic neuropathy, central/branch retinal artery occlusion, ophthalmoplegia externa, and ocular ischemic syndrome.Conclusions Carotid artery stenosis correlates with ocular ischemic diseases. Ophthalmologists must observe for ocular symptoms, which were the onset symptoms in some patients.

  11. Finite Element Analysis to Compare Stress Distribution of Four Different Framework Designs Zirconia Based Fixed Partial Denture%四种不同底层冠设计固定桥应力分布的有限元分析

    Institute of Scientific and Technical Information of China (English)

    郑志强; 林捷; 李厚轩; 陈群; 卢兆杰

    2013-01-01

    目的:使用三维有限元模型分析4种不同底层冠设计的3单位固定桥中界面应力分布情况。方法建立三维上颌第二前磨牙缺失3单位固定桥有限元模型,并进行4种不同底层冠设计。在桥体上施加600 N的垂直方向静荷载,以模拟最大咬合力。使用有限元分析不同设计的应力分布。结果Ⅰ型设计的最大拉应力在牙合面和龈端的饰瓷和底层冠交界处集中。Ⅱ型设计的最大拉应力在牙合面的饰瓷和底层冠交界处集中,龈端应力集中于桥体底部。Ⅲ型设计和Ⅳ型设计的拉应力分散于桥体底部。结论随着饰瓷包被面积减少,最大拉应力趋于从饰瓷和底层冠交界处向桥体和连接体底部分散。%Objective To use 3-dimensional finite element modeling to simulate stresses at the in-terface of 3-unit posterior fixed partial dentures (FPDs) made with 4 different framework designs . Meth-ods A 3-unit FPD was digitized and used to create 3-dimensional models of 4 framework preparation con-figurations . A load of 600 N was applied at the central point of the pontic’s occlusion surface . The stress values of 4 framework designs were calculated by finite element analysis . Results Tensile stress of Type Ⅰ design was maximal at the occlusal and gingival veneer-core interfaces . Tensile stress of TypeⅡ design was maximal at the occlusal veneer-core interface . Tensile stresses of Type Ⅲ and Type Ⅳ de-sign extended in the bottom of pontic . Conclusion In general ,the maximal tensile stresses of veneer-core interface extend in the bottom of pontic and connecters as the veneer area was decreased .

  12. Finite-Larmor-radius stability theory of EBT plasmas

    International Nuclear Information System (INIS)

    An eikonal ballooning-mode formalism is developed to describe curvature-driven modes of hot electron plasmas in bumpy tori. The formalism treats frequencies comparable to the ion-cyclotron frequency, as well as arbitrary finite Larmor radius and field polarization, although the detailed analysis is restricted to E/sub parallel/ = 0. Moderate hot-electron finite-Larmor-radius effects are found to lower the background beta core limit, whereas strong finite-Lamor-radius effects produce stabilization

  13. FINITE DIFFERENCE MODEL OF A CIRCULAR FIN WITH RECTANGULAR PROFILE

    OpenAIRE

    GİRGİN, İbrahim; EZGİ, Cüneyt

    2015-01-01

    Numerical methods are commonly used in engineering where the analytical resultsare not reached or as a support of experimental studies. Various techniques are being usedas a numeritical method as finite difference, finite volume or finite elements, etc. In thisstudy, numerical solutions are obtained for a circular fin of rectangular profile using finitedifference method, and the results are compared to the analytical solutions. It is seen thatthe analytical solution and numerical results are ...

  14. Coronary arterial fistulas

    Directory of Open Access Journals (Sweden)

    Qureshi Shakeel A

    2006-12-01

    Full Text Available Abstract A coronary arterial fistula is a connection between one or more of the coronary arteries and a cardiac chamber or great vessel. This is a rare defect and usually occurs in isolation. Its exact incidence is unknown. The majority of these fistulas are congenital in origin although they may occasionally be detected after cardiac surgery. They do not usually cause symptoms or complications in the first two decades, especially when small. After this age, the frequency of both symptoms and complications increases. Complications include 'steal' from the adjacent myocardium, thrombosis and embolism, cardiac failure, atrial fibrillation, rupture, endocarditis/endarteritis and arrhythmias. Thrombosis within the fistula is rare but may cause acute myocardial infarction, paroxysmal atrial fibrillation and ventricular arrhythmias. Spontaneous rupture of the aneurysmal fistula causing haemopericardium has also been reported. The main differential diagnosis is patent arterial duct, although other congenital arteriovenous shunts need to be excluded. Whilst two-dimensional echocardiography helps to differentiate between the different shunts, coronary angiography is the main diagnostic tool for the delineation of the anatomy. Surgery was the traditional method of treatment but nowadays catheter closure is recommended using a variety of closure devices, such as coils, or other devices. With the catheter technique, the results are excellent with infrequent complications. Disease name and synonyms Coronary arterial fistulas Coronary arterial fistulas or malformations

  15. Physical inactivity and arterial stiffness in COPD

    Directory of Open Access Journals (Sweden)

    Sievi NA

    2015-09-01

    Full Text Available Noriane A Sievi,1 Daniel Franzen,1 Malcolm Kohler,1,2 Christian F Clarenbach1 1Division of Pulmonology, University Hospital of Zurich, 2Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland Background: Arterial stiffness is an important predictor of cardiovascular risk besides classic cardiovascular risk factors. Previous studies showed that arterial stiffness is increased in patients with COPD compared to healthy controls and exercise training may reduce arterial stiffness. Since physical inactivity is frequently observed in patients with COPD and exercise training may improve arterial stiffness, we hypothesized that low daily physical activity may be associated with increased arterial stiffness. Methods: In 123 patients with COPD (72% men; mean [standard deviation] age: 62 [7.5] years; median [quartile] forced expiratory volume in 1 second 35 [27/65] %predicted, arterial stiffness was assessed by augmentation index (AI. Daily physical activity level (PAL was measured by an activity monitor (SenseWear Pro™ >1 week. The association between AI and PAL was investigated by univariate and multivariate regression analysis, taking into account disease-specific characteristics and comorbidities. Results: Patients suffered from moderate (35%, severe (32%, and very severe (33% COPD, and 22% were active smokers. Median (quartile PAL was 1.4 (1.3/1.5 and mean (standard deviation AI 26% (9.2%. PAL showed a negative association with AI (B=-9.32, P=0.017 independent of age, sex, blood pressure, and airflow limitation. Conclusion: In COPD patients, a higher PAL seems to favorably influence arterial stiffness and therefore may reduce cardiovascular risk. Clinical Trial Registration: www.ClinicalTrials.gov, NCT01527773 Keywords: activity monitor, airflow limitation, COPD, physical activity level

  16. Propagation of liquid surface waves over finite graphene structured arrays of cylinders

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Based on the multiple scattering method,this paper investigates a benchmark problem of the propagation of liquid surface waves over finite graphene (or honeycomb) structured arrays of cylinders.Comparing the graphene structured array with the square structured and with triangle structured arrays,it finds that the finite graphene structure can produce more complete band gaps than the other finite structures,and the finite graphene structure has less localized ability than the other finite structures.

  17. Structured Tree Outflow Condition for Blood Flow in Arteries

    Science.gov (United States)

    Olufsen, Mette

    1998-11-01

    Modeling blood flow and especially propagation of the pulse wave in the systemic arteries is of interests to the medical society because of the significance of the dicrotic wave. The pulse wave propagating along the larger arteries is reflected because of tapering and branching of the vessels, as well as the peripheral resistance, which is mainly stemming from the smaller arteries and arterioles. In order to avoid artificial reflections it is important to determine a boundary condition, representing the smaller arteries and arterioles, which is physiologically correct. In this work we have proposed a boundary condition based on a structured tree model. The result will be compared both with other modeling approaches as well as with results from measurements of flow and pressure at a number of locations along the larger arteries. The model for the larger arteries is based on the axisymmetrical Navier Stokes equations where the blood is assumed Newtonian and incompressible and the vessels are tapering. In the structured tree the model is based on a linearization of the axisymmetrical Navier-Stokes equations. The reason for setting up a structured tree is that the smaller arteries consist of an almost binary tree. Furthermore, the role of the smaller arteries is to allow blood perfusion of specific tissues. This is done in a structured and optimal way such that the smaller arteries cover the tissue evenly using a minimization principle.

  18. Helical CT evaluation of internal carotid artery stenoses

    International Nuclear Information System (INIS)

    To determine the utility of helical CT angiography in the evaluation of carotid artery stenoses, helical CT images (reconstructed three-dimensional images, reconstructed multiplanar images, and two-dimensional axial images) obtained from 60 patients were compared with images obtained using conventional angiography. Based on conventional angiographic criteria, 22 arteries had no stenosis, 26 had mild stenosis. 69 had severe stenosis, and 3 were occluded. All carotid bifurcations were clearly identified on helical CT scanning and there were no complications. There were no motion artifacts due to the short examination time. In normal arteries, reconstructed three-dimensional images provided accurate anatomic depiction of the carotid bifurcation. Calcification was present at the stenotic lesion in 52 arteries. In 43 arteries in which the stenotic lesion was free of calcification, the degree of carotid stenosis determined using reconstructed three-dimensional images correlated with that determined using conventional angiography. In 19 of 52 arteries with calcification at the stenotic lesion, the calcification was focal and did not obscure the vessel lumen significantly when viewed from multiple angles. In the other 33 arteries, the calcification was dense and/or circumferential, making it difficult to evaluate the axial images allowed evaluation of the vessel lumen in the area of calcification, and the degree of stenosis was similar to that determined by conventional angiography. In 3 arteries, occlusion of the internal carotid artery was seen in reconstructed three-dimensional images and was confirmed by conventional angiography. (K.H.)

  19. Helical CT evaluation of internal carotid artery stenoses

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Yoshinori; Imakita, Satoshi; Suzuki, Susumu; Yamamoto, Satoshi; Tsukahara, Tetsuya; Hashimoto, Nobuo [National Cardiovascular Center, Suita, Osaka (Japan)

    1997-06-01

    To determine the utility of helical CT angiography in the evaluation of carotid artery stenoses, helical CT images (reconstructed three-dimensional images, reconstructed multiplanar images, and two-dimensional axial images) obtained from 60 patients were compared with images obtained using conventional angiography. Based on conventional angiographic criteria, 22 arteries had no stenosis, 26 had mild stenosis. 69 had severe stenosis, and 3 were occluded. All carotid bifurcations were clearly identified on helical CT scanning and there were no complications. There were no motion artifacts due to the short examination time. In normal arteries, reconstructed three-dimensional images provided accurate anatomic depiction of the carotid bifurcation. Calcification was present at the stenotic lesion in 52 arteries. In 43 arteries in which the stenotic lesion was free of calcification, the degree of carotid stenosis determined using reconstructed three-dimensional images correlated with that determined using conventional angiography. In 19 of 52 arteries with calcification at the stenotic lesion, the calcification was focal and did not obscure the vessel lumen significantly when viewed from multiple angles. In the other 33 arteries, the calcification was dense and/or circumferential, making it difficult to evaluate the axial images allowed evaluation of the vessel lumen in the area of calcification, and the degree of stenosis was similar to that determined by conventional angiography. In 3 arteries, occlusion of the internal carotid artery was seen in reconstructed three-dimensional images and was confirmed by conventional angiography. (K.H.)

  20. The study of an angiography technique on rat coronary arteries

    International Nuclear Information System (INIS)

    Experimental cardiology investigations carried out on rat hearts involve problems with the anatomy and physiology of the coronary arteries. Coronarography is an imaging method of the coronary arteries which can be performed intravitaly as well as postmortem. The aim of the study was to present our own radiological method of postmortem imaging of the rats coronary arteries. The investigation was done on anatomical preparations of the hearts of rats of the Sprague-DawleyR and WistarR strains. In total, 69 arteriograms were obtained. The coronary arteries were filled with contrast medium consisting of 60% barium sulfate and a 10% solution of gelatin in a proportion of 3:2. Images of contrasted arteries were presented on X-ray film and, in some groups of rats, by a digital image converter. X-rays were performed using an apparatus we designed ourselves. This enabled image fixing of the arteries during full rotation of the heart about its axis. The described method of contrasting and image presentation of the rat's coronary arteries was able to show consecutively the shape and topography of the arteries in a precise, spatial way in repeatable experiments. The authors demonstrated the existence of anatomical and topographic differences in the images of the investigated arteries in the rat compared with the human heart. They pointed out the presence of arterioarterial anastomoses. The authors suggest further research to gain a better understanding of the anatomy and physiology of the coronary circulation of the rat. (author)

  1. Classical and all-floating FETI methods for the simulation of arterial tissues

    CERN Document Server

    Augustin, Christoph M; Steinbach, Olaf

    2015-01-01

    High-resolution and anatomically realistic computer models of biological soft tissues play a significant role in the understanding of the function of cardiovascular components in health and disease. However, the computational effort to handle fine grids to resolve the geometries as well as sophisticated tissue models is very challenging. One possibility to derive a strongly scalable parallel solution algorithm is to consider finite element tearing and interconnecting (FETI) methods. In this study we propose and investigate the application of FETI methods to simulate the elastic behavior of biological soft tissues. As one particular example we choose the artery which is - as most other biological tissues - characterized by anisotropic and nonlinear material properties. We compare two specific approaches of FETI methods, classical and all-floating, and investigate the numerical behavior of different preconditioning techniques. In comparison to classical FETI, the all-floating approach has not only advantages co...

  2. The prevalence of asymptomatic carotid artery disease in patients with peripheral vascular disease

    International Nuclear Information System (INIS)

    AIM: To determine the prevalence and severity of asymptomatic carotid artery disease in patients with peripheral arterial disease using colour duplex ultrasound, and to determine any relationship to the severity of peripheral arterial disease or other associated atherosclerotic risk factors. METHOD: Two hundred patients with known peripheral arterial disease but no previous cerebrovascular history were prospectively screened for carotid artery disease, and any identified internal carotid artery (ICA) stenosis graded using established duplex ultrasound criteria. A detailed medical questionnaire established the presence or absence of associated risk factors, and the severity of peripheral arterial disease was graded and correlated with these. RESULTS: A total of 50 patients (25%) were found to have an ICA stenosis of > 50%, with 27 (13.5%) of these having > 70% stenosis. Bilateral ICA stenosis (> 50%) was seen in 21 (10.5%) patients, of which 10 (5%) had bilateral stenoses of > 70%. No correlation was found between the severity of peripheral arterial disease and the presence of significant carotid artery disease, or between the latter and individual atherosclerotic risk factors. CONCLUSION: This study demonstrates a relatively high prevalence of significant carotid artery disease in patients with peripheral arterial disease compared to the general population. The significance of this with respect to the future screening of defined populations for asymptomatic carotid artery disease is discussed, with reference to recent studies comparing surgical and medical management of asymptomatic carotid artery disease. Pilcher, J.M., Danaher, J., Khaw, K.-T. (2000)

  3. Acute arterial infarcts in patients with severe head injuries

    Directory of Open Access Journals (Sweden)

    Deepak Agrawal

    2012-01-01

    Full Text Available Aims and Objectives: To study the incidence, demographic profile, and outcome of patients with severe closed head injuries who develop acute arterial infarcts. Materials and Methods: Patients with severe head injury (Glasgow coma score (GCS ≤8 presenting within 8 h of injury in the Department of Neurosurgery over a period of 5 months were enrolled in the study. Patients with penetrating head injury, infarct due to herniation and iatrogenic arterial injuries were excluded from the study. Only arterial infarcts developing within 8 h of injury were included in the study. A computed tomography (CT head was done on all patients within 8 h of injury and repeated if necessary. Arterial infarct was defined as well-demarcated wedge-shaped hypodensity corresponding to an arterial territory on plain CT of the head. Outcome was assessed using Glasgow outcome score (GOS at 1 month post-injury or at death (whichever came earlier. Results: Forty-four patients of severe head injury were included in the study during the above period. Of these, four patients (9.1% had arterial infarcts on the initial CT scan. The male:female ratio was 1:3. The mean age was 54 years (range 3-85 years. Two patients had infarcts in the middle cerebral artery distribution and two in the superior cerebellar artery distribution. Poor outcome (GOS 1-3 was seen in 100% of the patients with arterial infarct compared to 52.5% (n=21 in patients with severe head injury without arterial infarct. Conclusions: A significant percentage of patients with severe head injury have arterial infarcts on admission, which may imply arterial injury. Our study shows that these patients have a poorer prognosis vis-a-vis patient without these findings.

  4. Mechanical thrombectomy in basilar artery thrombosis

    DEFF Research Database (Denmark)

    Fesl, Gunther; Holtmannspoetter, Markus; Patzig, Maximilian; Mayer, Thomas E; Pfefferkorn, Thomas; Brueckmann, Hartmut; Schulte-Altedorneburg, Gernot

    2014-01-01

    PURPOSE: Multiple endovascular devices have been used for mechanical thrombectomy (MT) in basilar artery occlusion (BAO) for >10 years. Based on a single-center experience during the course of one decade, we present data on safety and efficacy of previous MT devices compared with modern stent ret...

  5. Anomalous right coronary artery arising from left anterior descending artery

    Directory of Open Access Journals (Sweden)

    M.L. Sreenivas Kumar

    2012-07-01

    Full Text Available A 54-year-old male patient presented with acute myocardial infarction involving left anterior descending and right coronary artery territories. Coronary angiogram showed a single coronary artery with right coronary artery arising from left anterior descending artery (LAD, which coursed anterior to right ventricular outflow tract and thrombotic lesion in mid left anterior descending artery before origin of right coronary artery. The patient was treated with thrombolytic therapy and glycoprotein IIb/IIIa inhibitors. Anomalous origin of right coronary artery as a branch of LAD is a very rare type of congenital coronary artery anomalies. It is important to recognize this anomaly as it can be associated with extensive myocardial ischemia and sudden cardiac death in young persons even without atherosclerosis.

  6. ARTERIAL ELASTICITY IN AMERICAN INDIAN AND CAUCASIAN CHILDREN, ADOLESCENTS, AND YOUNG ADULTS

    OpenAIRE

    Gardner, Andrew W; Parker, Donald E.

    2011-01-01

    We compared arterial elasticity in American Indian and Caucasian children, adolescents, and young adults, and we assessed whether demographic, body composition, and ambulatory activity measures were predictive of arterial elasticity within each group. Fifty-one American Indians and 66 Caucasians between the ages of 8 and 30 years were assessed on large artery elasticity index, small artery elasticity index, body fat percentage, and daily ambulatory activity during seven consecutive days. Amer...

  7. Transcutaneous measurement of the arterial input function in positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) provides a powerful tool in medical research. Biochemical function can be both precisely localized and quantitatively measured. To achieve reliable quantitation it is necessary to know the time course of activity concentration in the arterial blood during the measurement. In this study the arterial blood curve from the brachial artery is compared to the activity measured in the internal carotid artery with a new transcutaneous detector

  8. EFFECT OF MAGNETIC FIELD ON BLOOD FLOW THROUGH AN ARTERY: A NUMERICAL MODEL

    OpenAIRE

    J Misra; Shit, G.

    2007-01-01

    In this paper we have investigated the unsteady flow of blood by treating it as an incompressible, Newtonian, electrically conducting fluid in a straight segment of an elastic artery subject to a uniform transverse magnetic field. The problem is solved numerically with the theoretical assumption of 'local flow' model [?]. A sinusoidal variation of the arterial wall motion and a pulsatile pressure gradient have been studied. An implicit finite difference technique is used to analyze the flow. ...

  9. Visceral periadventitial adipose tissue regulates arterial tone of mesenteric arteries.

    Science.gov (United States)

    Verlohren, Stefan; Dubrovska, Galyna; Tsang, Suk-Ying; Essin, Kirill; Luft, Friedrich C; Huang, Yu; Gollasch, Maik

    2004-09-01

    Periadventitial adipose tissue produces vasoactive substances that influence vascular contraction. Earlier studies addressed this issue in aorta, a vessel that does not contribute to peripheral vascular resistance. We tested the hypothesis that periadventitial adipose tissue modulates contraction of smaller arteries more relevant to blood pressure regulation. We studied mesenteric artery rings surrounded by periadventitial adipose tissue from adult male Sprague-Dawley rats. The contractile response to serotonin, phenylephrine, and endothelin I was markedly reduced in intact vessels compared with vessels without periadventitial fat. The contractile response to U46619 or depolarizing high K+-containing solutions (60 mmol/L) was similar in vessels with and without periadventitial fat. The K+ channel opener cromakalim induced relaxation of vessels precontracted by serotonin but not by U46619 or high K+-containing solutions (60 mmol/L), suggesting that K+ channels are involved. The intracellular membrane potential of smooth muscle cells was more hyperpolarized in intact vessels than in vessels without periadventitial fat. Both the anticontractile effect and membrane hyperpolarization of periadventitial fat were abolished by inhibition of delayed-rectifier K+ (K(v)) channels with 4-aminopyridine (2 mmol/L) or 3,4-diaminopyridine (1 mmol/L). Blocking other K+ channels with glibenclamide (3 micromol/L), apamin (1 micromol/L), iberiotoxin (100 nmol/L), tetraethylammonium ions (1 mmol/L), tetrapentylammonium ions (10 micromol/L), or Ba2+ (3 micromol/L) had no effect. Longitudinal removal of half the perivascular tissue reduced the anticontractile effect of fat by almost 50%, whereas removal of the endothelium had no effect. We suggest that visceral periadventitial adipose tissue controls mesenteric arterial tone by inducing vasorelaxation via K(v) channel activation in vascular smooth muscle cells. PMID:15302842

  10. Supersymmetry at finite temperature

    International Nuclear Information System (INIS)

    The consequences of the incorporation of finite temperature effects in fields theories are investigated. Particularly, we consider the sypersymmetric non-linear sigma model, calculating the effective potencial in the large N limit. Initially, we present the 1/N expantion formalism and, for the O(N) model of scalar field, we show the impossibility of spontaneous symmetry breaking. Next, we study the same model at finite temperature and in the presence of conserved charges (the O(N) symmetry's generator). We conclude that these conserved charges explicitly break the symmetry. We introduce a calculation method for the thermodynamic potential of the theory in the presence of chemical potentials. We present an introduction to Supersymmetry in the aim of describing some important concepts for the treatment at T>0. We show that Suppersymmetry is broken for any T>0, in opposition to what one expects, by the solution of the Hierachy Problem. (author)

  11. Hadronic property at finite density

    OpenAIRE

    Takaishi, Tetsuya

    2004-01-01

    We report on three topics on finite density simulations: (i) the derivative method for hadronic quantities, (ii) phase fluctuations in the vicinity of the critical temperature and (iii) the density of states method at finite isospin density.

  12. Finite Sets and Counting

    OpenAIRE

    Preston, Chris

    2008-01-01

    We start by presenting a theory of finite sets using the approach which is essentially that taken by Whitehead and Russell in Principia Mathematica}, and which does not involve the natural numbers (or any other infinite set). This theory is then applied to prove results about structures which, like the natural numbers, satisfy the principle of mathematical induction, but do not necessarily satisfy the remaining Peano axioms.

  13. Finite Temperature Strings

    OpenAIRE

    Bowick, Mark J.

    1992-01-01

    These are lecture notes for the 1992 Erice Workshop on String Quantum Gravity and Physics at the Planck Energy Scale. In this talk a review of earlier work on finite temperature strings was presented. Several topics were covered, including the canonical and microcanonical ensemble of strings, the behavior of strings near the Hagedorn temperature as well as speculations on the possible phases of high temperature strings. The connection of the string ensemble and, more generally, statistical sy...

  14. Infrared finite electron propagator

    International Nuclear Information System (INIS)

    We investigate the properties of a dressed electron which reduces, in a particular class of gauges, to the usual fermion. A one-loop calculation of the propagator is presented. We show explicitly that an infrared finite, multiplicative, mass shell renormalization is possible for this dressed electron, or, equivalently, for the usual fermion in the above-mentioned gauges. The results are in complete accord with previous conjectures. copyright 1997 The American Physical Society

  15. Finite elements in fluids

    International Nuclear Information System (INIS)

    This book discusses the topics in the general field of finite element analysis of flow problems and describes the major advances over the last two years and introduces new powerful methods for high-speed and free-surface flows, and discusses applications. The contents include: General Topics, Computational and Mathematical Aspects. High-speed and Transonic flows. Hydraulics, Viscous Flow, Boundary-Layers, MHD. Free Surface Flow. Index

  16. Intima-media thickness and arterial stiffness of carotid artery in Korean patients with Behçet's disease.

    Science.gov (United States)

    Rhee, Moo-Yong; Chang, Hyun Kyu; Kim, Seong-Kyu

    2007-06-01

    Behçet's disease (BD) is a systemic vasculitis involving diverse sizes of arteries and veins. We performed this study to evaluate the vascular changes by assessment of the arterial stiffness and intima-media thickness (IMT) of carotid artery in Korean patients with BD. Forty-one patients with BD and age-, and sex-matched 53 healthy subjects were recruited in this study. Carotid arterial stiffness and IMT were assessed by using high-resolution B-mode ultrasonography. Arterial stiffness parameters such as carotid arterial distensibility coefficient, stiffness index, and incremental elastic modulus (E(inc)) were significantly increased in BD patients compared with those in healthy subjects, but not in IMT. Positive relationship was noted between age and IMT, whereas age of onset was significantly associated with arterial stiffness in BD. This finding suggests impaired endothelial function before visible structural changes of arterial wall in BD. Age and age of onset may be an independent risk factor for carotid IMT and arterial stiffness, respectively. Further studies in more large populations are required to confirm our results. PMID:17596642

  17. On Finite Alphabet Compressive Sensing

    OpenAIRE

    Das, Abhik Kumar; Vishwanath, Sriram

    2013-01-01

    This paper considers the problem of compressive sensing over a finite alphabet, where the finite alphabet may be inherent to the nature of the data or a result of quantization. There are multiple examples of finite alphabet based static as well as time-series data with inherent sparse structure; and quantizing real values is an essential step while handling real data in practice. We show that there are significant benefits to analyzing the problem while incorporating its finite alphabet natur...

  18. Symbolic computation with finite quandles

    OpenAIRE

    Henderson, Richard; Macedo, Todd; Nelson, Sam

    2005-01-01

    Algorithms are described and Maple implementations are provided for finding all quandles of order $n$, as well as computing all homomorphisms between two finite quandles or from a finitely presented quandle (e.g., a knot quandle) to a finite quandle, computing the automorphism group of a finite quandle, etc. Several of these programs work for arbitrary binary operation tables and hence algebraic structures other than quandles. We also include a stand-alone C program which finds quandles of or...

  19. Finite element simulation of asphalt fatigue testing

    DEFF Research Database (Denmark)

    Ullidtz, Per; Kieler, Thomas Lau; Kargo, Anders

    damage mechanics.The paper describes how continuum damage mechanics may be used with a finite element program to explain the progressive deterioration of asphalt mixes under laboratory fatigue testing. Both constant stress and constant strain testing are simulated, and compared to the actual results from...

  20. Hemisphere jet mass distribution at finite Nc

    Directory of Open Access Journals (Sweden)

    Yoshikazu Hagiwara

    2016-05-01

    Full Text Available We perform the leading logarithmic resummation of nonglobal logarithms for the single-hemisphere jet mass distribution in e+e− annihilation including the finite-Nc corrections. The result is compared with the previous all-order result in the large-Nc limit as well as fixed-order perturbative calculations.

  1. Left main coronary artery compression in pulmonary arterial hypertension

    DEFF Research Database (Denmark)

    Al-Badri, Kadhem Helo Abbas; Jensen, Jesper Møller; Christiansen, Evald H;

    2015-01-01

    In patients with pulmonary arterial hypertension (PAH), chest pain is most likely due to right ventricular demand ischemia. We report a patient with idiopathic PAH who developed severe angina due to extrinsic compression of the left main coronary artery (LMCA) from a dilated pulmonary artery trunk...

  2. Left Anterior Descending Artery-Pulmonary Artery Fistula

    Directory of Open Access Journals (Sweden)

    Turan Ege

    2011-12-01

    Full Text Available Despite the fact that coronary arteriovenous fistulas constitute approximately half (48% of coronary artery anomalies, they are rarely seen anomalies. In this report,we aim to present a coronary arteriovenous fistula case detected during a coronary angiography between left anterior descending artery and pulmonary artery.

  3. Estudo comparativo da pressão arterial e da prevalência de hipertensão arterial em duas coortes sucessivas (1975-1976 de estudantes de 16 a 25 anos, Botucatu, SP, Brasil Blood pressure levels and hipertension prevalence in 16 to 25 year-old students in Botucatu, S. Paulo, Brazil. A comparative study of two successive cohorts, 1975-1976

    Directory of Open Access Journals (Sweden)

    Dináh Borges de Almeida

    1978-12-01

    Full Text Available Com o objetivo de determinar os níveis de pressão arterial e a prevalência de hipertensão arterial em uma população jovem, foram realizados pesquisas em dois anos sucessivos em 1.288 e 736 estudantes de Botucatu, SP (Brasil tendo sido comparados os resultados obtidos. As médias das pressões sistólicas da população estudada e dos dois grupos etários desta população (16 a 20 anos e 21 a 25 anos foram idênticas em ambos os anos, tendo as médias das pressões diastólicas diferido de no máximo 2 mmHg; as médias, tanto sistólicas quanto diastólicas, dos dois sexos e da parcela branca da população estudada quanto à idade e sexo também diferiram de no máximo 2 mmHg. As médias da população estudada e sua parcela branca, em ambos os anos, foram superiores no sexo masculino e no grupo etário de 21 a 25 anos. Na população negra e amarela houve disparidade de resultados entre 1975 e 1976, indicando influência da exiguidade do tamanho dos contigentes negro e amarelo desta população. A prevalência de hipertensão arterial (pressão sistólica igual ou maior que 140 mmHg e diastólica igual ou maior que 90 mmHg foi de 5,04% em 1975 e 6,22% em 1976, tendo sido em ambos os anos maior no sexo masculino do que no feminino e no grupo de 21 a 25 do que no de 16 a 20 anos.To determine the prevalence of hypertension and blood pressure levels in a young population group, two groups, one of 1288 students and another of 736, all from Botucatu, were investigated during two consecutive years, and the results were then compared. The mean values for systolic readings of the whole population, as for the two age groups (16 to 20 and 21 to 25 years old, were identical for both years studied; the diastolic mean values differed by 2 mmHg at most. The mean systolic and diastolic reading for both sexes and among the whites also differed by 2 mmHg at most. The mean values for the whole population and among the white population were higher for males

  4. Spiral CT Scan for Detecting Coronary Artery Stenosis

    Directory of Open Access Journals (Sweden)

    A. Soltani Shirazi

    2005-07-01

    Full Text Available Background/ Objective: Coronary vessel calcification is an obvious sign of atherosclerotic disease of coronary arteries. Electron beam CT scan is currently the imaging modality of choice for assessing coronary artery calcifications. However, its high cost makes it unavailable to a large number of medical centers. We carried out this study to compare the diagnostic yield of spiral CT scans as an alternative, to coronary angiography. Patients and Methods: A hundred patients suspicious of having coronary artery disease (CAD underwent angiography as well as spiral CT scan of the heart. On CT scan, calcification of >90 Hounsfield on a surface area of >0.5 mm2, anatomically superimposed on coronary arteries were highlighted as calcified areas using the volumetric feature of the scanner. The findings were compared to angiographic results. Results: Of 100 patients enrolled (62 males, 69 had coronary artery obstruction (>50% stenosis on angiography. Angiography was normal in the rest. Spiral CT scan had a sensitivity of 94% and a specificity of 61% for the diagnosis of coronary artery disease. The PPV and NPV were 84% and 79%, respectively. Among the coronary arteries, LAD findings had the highest sensitivity (92% and the lowest specificity (65% in the diagnosis of CAD. With age, spiral CT scan had more sensitivity and less specificity for CAD. Conclusion: Detecting calcification by spiral CT scanning could be a useful non-invasive method for diagnosis and evaluation of coronary artery stenosis.

  5. Finite extensions of Bessel sequences

    OpenAIRE

    Bakić, Damir; Berić, Tomislav

    2015-01-01

    The paper studies finite extensions of Bessel sequences in infinite-dimensional Hilbert spaces. We provide a characterization of Bessel sequences that can be extended to frames by adding finitely many vectors. We also characterize frames that can be converted to Parseval frames by finite-dimensional perturbations. Finally, some results on excesses of frames and near-Riesz bases are derived.

  6. About Peripheral Artery Disease (PAD)

    Science.gov (United States)

    ... Tools & Resources Stroke More About Peripheral Artery Disease (PAD) Updated:Mar 23,2016 Peripheral artery disease (PAD) ... critical regions of the body. Quick Facts about PAD View an illustration of PAD The most common ...

  7. Pharmacological modulation of arterial stiffness.

    LENUS (Irish Health Repository)

    Boutouyrie, Pierre

    2011-09-10

    Arterial stiffness has emerged as an important marker of cardiovascular risk in various populations and reflects the cumulative effect of cardiovascular risk factors on large arteries, which in turn is modulated by genetic background. Arterial stiffness is determined by the composition of the arterial wall and the arrangement of these components, and can be studied in humans non-invasively. Age and distending pressure are two major factors influencing large artery stiffness. Change in arterial stiffness with drugs is an important endpoint in clinical trials, although evidence for arterial stiffness as a therapeutic target still needs to be confirmed. Drugs that independently affect arterial stiffness include antihypertensive drugs, mostly blockers of the renin-angiotensin-aldosterone system, hormone replacement therapy and some antidiabetic drugs such as glitazones. While the quest continues for \\'de-stiffening drugs\\

  8. Combination of rare right arterial variation with anomalous origins of the vertebral artery, aberrant subclavian artery and persistent trigeminal artery. A case report.

    Science.gov (United States)

    Ishihara, H; San Millán Ruíz, D; Abdo, G; Asakura, F; Yilmaz, H; Lovblad, K O; Rüfenacht, D A

    2011-09-01

    A 32-year-old woman hospitalized for subarachnoid hemorrhage showed rare arterial variation on the right side with anomalous origins of the vertebral artery, aberrant subclavian artery and persistent trigeminal artery. Angiography showed the right vertebral artery to originate from the right common carotid artery, the right subclavian artery to arise separately from the descending aorta, and persistent trigeminal artery on the right side. The possible embryonic mechanism of this previously unreported variant combination is discussed. PMID:22005696

  9. Applications of an exponential finite difference technique

    Science.gov (United States)

    Handschuh, Robert F.; Keith, Theo G., Jr.

    1988-01-01

    An exponential finite difference scheme first presented by Bhattacharya for one dimensional unsteady heat conduction problems in Cartesian coordinates was extended. The finite difference algorithm developed was used to solve the unsteady diffusion equation in one dimensional cylindrical coordinates and was applied to two and three dimensional conduction problems in Cartesian coordinates. Heat conduction involving variable thermal conductivity was also investigated. The method was used to solve nonlinear partial differential equations in one and two dimensional Cartesian coordinates. Predicted results are compared to exact solutions where available or to results obtained by other numerical methods.

  10. Liver cirrhosis and arterial hypertension

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Møller, Søren

    2006-01-01

    blood pressure. This review considers the alterations in systemic hemodynamics in patients with cirrhosis in relation to essential hypertension and arterial hypertension of the renal origin. Subjects with arterial hypertension (essential, secondary) may become normotensive during the development of...... cirrhosis, and arterial hypertension is rarely manifested in patients with cirrhosis, even in cases with renovascular disease and high circulating renin activity. There is much dispute as to the understanding of homoeostatic regulation in cirrhotic patients with manifest arterial hypertension. This most...

  11. Calculation of narrowband lowpass filters with finite impulse response

    OpenAIRE

    Lanne, A. A.; Merkucheva, T. V.; Solonina, A. I.

    2009-01-01

    This study provides a review of digital filters known under the name “interpolated finite impulse response filters” (IFIR filters) that make it possible to create narrowband lowpass filters (LPF) with substantially reduced computational load and, consequently, a simpler design as compared with the conventional finite impulse response filters (FIR filters).

  12. Optimization of plate thickness using finite different method

    International Nuclear Information System (INIS)

    A finite difference numerical method of solving biharmonic equation is presented. The biharmonic equation and plate theory are used to solve a classical engineering problem involving the optimisation of plate thickness to minimise deformations and stresses in the plate. Matlab routines were developed to solve the resulting finite difference equations. The results from the finite difference method were compared with results obtained using ANSYS finite element formulation. Using the finite difference method, a plate thickness of 277 mm was obtained with a mesh size of 3 m and a plate thickness of 271 mm was obtained with a mesh size of 1 m., whiles using ANSYS finite element formulation, a plate thickness of 270 mm was obtained. The significance of these results is that, by using off-the-shelf general application tool and without resorting to expensive dedicated application tool, simple engineering problems could be solved. (au)

  13. Translation operator for finite dmensional electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Howard, A.Q. Jr.

    1981-04-01

    Computation of electromagnetic fields in particular applications is usually accompanied by the adhoc assumption that the field contains a finite number of degrees of freedom. Herein, this assumption is made at the outset. It is shown that if an annular region between two closed surfaces contains no sources or sinks and is isotropic, lossless and homogeneous, a unique translation operator can be defined algebraically. Conservation of energy defines the translation operator T to within an arbitrary unitary transformation. The conditions of causality, unitarity and energy conservation are shown to uniquely determine T. Both scalar and vector fields are treated. In both of these cases, frequency and time domain transforms are computed. The transform T is compared with the analagous one as derived from the time domain Stratton-Chu Formulation. The application to a radiation condition boundary constraint on finite difference and finite element computations is discussed.

  14. Persistent Trigeminal Artery

    Directory of Open Access Journals (Sweden)

    Dijo T George

    2015-04-01

    Full Text Available Trigeminal artery is the commonest of the four primitive anastomoses between the carotid and vertebrobasilar system that may rarely persist in adults, with an angiographic incidence of 0.1 - 0.6%. We present the CT and MR angiograms of a patient who presented with a minor stroke and was detected to have this anomaly and briefly discuss the significance

  15. Smoking and hyperlipidemia are important risk factors for coronary artery spasm

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Objective To investigate the role of coronary artery spasm in the etiology of chest pain lacking significant coronary stenosis and to identify the clinical risk factors related to coronary artery spasm. Methods Two hundred and seventy five patients with chest pain, but without significant coronary artery stenosis underwent the intracoronary acetylcholine test. Coronary artery spasm was diagnosed while coronary artery stenosis increased to 90% and was accompanied by the usual chest pain with or without ischemic changes on electrocardiogram. Logistic regression was employed to investigate the relationships between coronary artery spasm and sex, age, hypertension, diabetes mellitus, smoking, hyperlipidemia and results of electrocardiographic treadmill stress test. Left ventricular ejection fraction and end diastolic pressure were compared between spasm group and non-spasm group. Results Coronary artery spasm was detected in 103 out of 271 patients, a rate of 38%. Logistic regression analysis showed that smoking and hyperlipidemia increased the relative risk of coronary artery spasm 4.2 times and 2.3 times, respectively. There was a significantly negative relationship between diabetes mellitus and coronary artery spasm. Furthermore, there was no coronary artery spasm detected in left ventricular ejection fraction and end diastolic pressure. Conclusions Coronary artery spasm was one of the important etiological factors for patients with chest pain but no coronary artery stenosis. Smoking and hyperlipidemia were the main clinical risk factors for coronary artery spasm.

  16. Local homodynamic changes induced by radial artery catheterization with color doppler ultrasound

    International Nuclear Information System (INIS)

    Objective: To examine the possible local damaging effects of arterial monitoring catheters on arterial functioning in patients after elective surgery with color Doppler ultrasound. Methods: Thirty patients who underwent elective surgery with a radial artery catheter were examined. The 2-dimentional ultrasonography and the blood flow of each radial and ulnar artery were examined before the puncture, 30 minutes and 24-hour after removal. Artery diameter, peak velocity of blood flow and patency were examined. The blood flow velocity of ulnar artery/the blood flow velocity of radial artery ratio were compared. The non-affected arm was used as the control. Results: Artery monitoring catheters caused a remarkable functional arterial change in the affected arm. The blood flow velocity of ulnar artery/the blood flow velocity of radial artery ratio were increased 30 minutes and 24 hour after removal. There were no severe clinical complications. Conclusion: Radial artery blood flow can be observed clearly with color Doppler ultrasound. Aseries of data were measured and recorded. There is significant change in the hemodynamic function of the artery during certain period of time. (authors)

  17. 自然单元法与有限元法和无单元法的比较%Comparative study on natural element method, finite element method and meshless method

    Institute of Scientific and Technical Information of China (English)

    琚宏昌; 刘平伟; 张胜利

    2012-01-01

    In order to analyze the characteristics of the natural element method (NEM), comparison among NEM and the finite element method (FEM) and the meshless method (MM) is carried out. The basic principles of NEM is introduced in this paper, that is, NEM is based on the Voronoi tessellation of a set of nodes and the Delaunay triangulation of the topological dual of the Voronoi diagram, taking the natural neighbor interpolation as trial function and building the equilibrium equations to solve problems. NEM is considered to be a meshless method, and its shape functions can be constructed simply. By analyzing the basic properties of the three methods, the paper shows that the three methods have the same condition: partition of unity. Similar to FEM, NEM can exactly interpolate piece-wise linear boundary conditions. However, NEM is advantageous over the traditional FEM in solving problems with propagation of crack and large deformation and so on.%为了分析自然单元法的特点,进行了自然单元法与有限元法、无单元法的比较,介绍了自然单元法的基本原理,即基于点集的Voronoi图及其对偶Delaunay三角剖分,以自然邻节点为插值试函数,构建平衡方程进行求解.剖析了3种方法的基本性质,说明自然单元法、有限元法和无单元法均具有单位分解条件.认为自然单元法是一种无网格方法,其形函数构造简单,能与有限元法一样直接施加本质边界条件,可以求解有限元法较难处理的裂纹扩展和大变形等问题.

  18. Basilar Artery Aneurysm at a Persistent Trigeminal Artery Junction

    Science.gov (United States)

    Aguiar, G.B.; Conti, M.L.M.; Veiga, J.C.E.; Jory, M.; Souza, R.B.

    2011-01-01

    Summary The trigeminal artery is an anastomosis between the embryonic precursors of the vertebrobasilar and carotid systems, and may persist into adult life. The association of the persistent primitive trigeminal artery (PTA) with cerebral aneurysm is well documented in the literature and, in general, aneurysms are located in the anterior circulation. We describe a patient who presented with a panencephalic Fisher III subarachnoid hemorrhage due to rupture of an intracranial aneurysm. Digital arteriography showed a saccular aneurysm in the middle third of the basilar artery, adjacent to the junction with a persistent trigeminal artery. She was submitted to endovascular treatment with embolization of the basilar artery aneurysm with coils. Aneurysms at the PTA junction with the basilar artery are rare. This paper describes a case of PTA associated with an aneurysm in the basilar artery at PTA junction and briefly reviews the literature. PMID:22005697

  19. Renal artery stenosis after radiotherapy for Ewing's sarcoma

    International Nuclear Information System (INIS)

    Background: the fact that therapeutic irradiation can induce significant stenosis in the arteries of the head, neck, and chest, as welt as in the aorta and the iliac arteries, is familiar in daily practice and well documented in the literature. By contrast, radiation-induced renal artery stenosis seems to be a less widely known complication. Patients and methods: the sudden onset of medically refractory arterial hypertension and coma in a 27-year-old man is reported, who had been treated at age 20 with chemotherapy and radiotherapy for Ewing's sarcoma in the lumbar region. This treatment had been performed at the hospital of Sion, Switzerland in 2001. Also, the relevant literature from 1965 to 2007 is reviewed to underscore various aspects of this problem and to demonstrate the clinical relevance of renal artery stenosis as a potential long-term sequela of radiotherapy. Conclusion: radiation-induced renal artery stenosis has only rarely been described in the literature, but arterial hypertension due to radiation-induced renal artery stenosis is a serious long-term sequela that can appear at a latency of up to 20 years after treatment. The paucity of reports presumably reflects the lesser frequency of radiotherapy for retroperitoneal tumors as compared to head-and-neck cancers, as well as lower awareness of the problem due to diagnostic bias in the era before CT and MRI were in routine use: at that time, carotid artery stenosis was easy to diagnose by ultrasonography, while radiation-induced renal artery stenosis, whose real incidence may well be higher, probably often went undetected. Thus, when a patient with a history of abdominal or retroperitoneal radiotherapy unexpectedly develops intractable hypertension, radiation-induced renal artery stenosis must be included in the differential diagnosis. (orig.)

  20. Computing with Hereditarily Finite Sequences

    CERN Document Server

    Tarau, Paul

    2011-01-01

    e use Prolog as a flexible meta-language to provide executable specifications of some fundamental mathematical objects and their transformations. In the process, isomorphisms are unraveled between natural numbers and combinatorial objects (rooted ordered trees representing hereditarily finite sequences and rooted ordered binary trees representing G\\"odel's System {\\bf T} types). This paper focuses on an application that can be seen as an unexpected "paradigm shift": we provide recursive definitions showing that the resulting representations are directly usable to perform symbolically arbitrary-length integer computations. Besides the theoretically interesting fact of "breaking the arithmetic/symbolic barrier", the arithmetic operations performed with symbolic objects like trees or types turn out to be genuinely efficient -- we derive implementations with asymptotic performance comparable to ordinary bitstring implementations of arbitrary-length integer arithmetic. The source code of the paper, organized as a ...

  1. Peripheral arterial angiography and interventional treatment in diabetic foot ulcers

    International Nuclear Information System (INIS)

    Objective: To assess the changes of peripheral arteries and choice of interventional treatment in diabetic foot ulcers. Methods: Thirty-six diabetic patients with foot ulcers were examined by lower extremity DSA with simultaneous ultrasonic Doppler examination for correlative study and interventional treatment carried out in 17 segmental stenotic cases. Among them, 12 patients were treated by PTA and 5 patients by intravascular stenting. Results: Irregular stenoses and obstruction were observed in all patients with peripheral foot ulcers. DSA examination was more reliable comparing with Doppler examination for demonstration of the arterial injury above the level of popliteal artery. PTA and primary stenting were effective in all of these subjects outcoming with promotion of the lower extremity arterial blood perfusion and foreseen curing efficacy. Conclusions: Peripheral arterial stenoses were common in diabetic patients with foot ulcers. In clinical practice, DSA examination and interventional treatment could give a fertile prognosis and reduce disabling

  2. Performance and scalability of finite-difference and finite-element wave-propagation modeling on Intel's Xeon Phi

    NARCIS (Netherlands)

    Zhebel, E.; Minisini, S.; Kononov, A.; Mulder, W.A.

    2013-01-01

    With the rapid developments in parallel compute architectures, algorithms for seismic modeling and imaging need to be reconsidered in terms of parallelization. The aim of this paper is to compare scalability of seismic modeling algorithms: finite differences, continuous mass-lumped finite elements a

  3. Finite Temperature Quark Confinement

    OpenAIRE

    Meisinger, Peter N.; Ogilvie, Michael C.

    1997-01-01

    Confinement may be more easily demonstrated at finite temperature using the Polyakov loop than at zero temperature using the Wilson loop. A natural mechanism for confinement can arise via the coupling of the adjoint Polyakov loop to F_{mu nu}^2. We demonstrate this mechanism with a one-loop calculation of the effective potential for SU(2) gluons in a background field consisting of a non-zero color magnetic field and a non-trivial Polyakov loop. The color magnetic field drives the Polyakov loo...

  4. Combinatorics of finite sets

    CERN Document Server

    Anderson, Ian

    2011-01-01

    Coherent treatment provides comprehensive view of basic methods and results of the combinatorial study of finite set systems. The Clements-Lindstrom extension of the Kruskal-Katona theorem to multisets is explored, as is the Greene-Kleitman result concerning k-saturated chain partitions of general partially ordered sets. Connections with Dilworth's theorem, the marriage problem, and probability are also discussed. Each chapter ends with a helpful series of exercises and outline solutions appear at the end. ""An excellent text for a topics course in discrete mathematics."" - Bulletin of the Ame

  5. Finite element modeling of the Circle of Willis from magnetic resonance data

    Science.gov (United States)

    Cebral, Juan R.; Castro, Marcelo; Soto, Orlando; Loehner, Rainald; Yim, Peter J.; Alperin, Noam

    2003-05-01

    This paper presents a methodology to construct realistic patient-specific computational fluid dynamics models of the circle of Willis (CoW) using magnetic resonance angiography (MRA) data. Anatomical models are reconstructed from MRA images using tubular deformable models along each arterial segment and a surface-merging algorithm. The resulting models are smoothed and used to generate finite element (FE) grids. The incompressible Navier-Stokes equations are solved using a stabilized FE formulation. Physiologic flow conditions are derived from phase-contrast MR velocity measurements. The methodology was tested on image data of a normal volunteer. A pulsatile flow solution was obtained. Measured flow rates were prescribed in the internal carotid arteries, vertebral arteries, middle cerebral arteries and anterior cerebral arteries. Pressure boundary conditions were imposed in the posterior cerebral arteries. Visualizations of the complex flow patterns and wall shear stress distributions were produced. Potential applications of these FE models include: study the role of the communicating arteries during arterial occlusions and after endovsascular interventions, calculate transport of drugs, evaluate accuracy of 1D flow models, and evaluate vascular bed models used to impose boundary conditions when flow data is unavailable or incomplete.

  6. Implication of the presence of a variant hepatic artery during the Whipple procedure

    Directory of Open Access Journals (Sweden)

    Mercedes Rubio-Manzanares-Dorado

    2015-07-01

    Full Text Available Introduction: The anatomical variants of the hepatic artery may have important implications for pancreatic cancer surgery. The aim of our study is to compare the outcome following a pancreatoduodenectomy (PD in patients with or without a variant hepatic artery arising from superior mesenteric artery. Material and methods: We reviewed 151 patients with periampullary tumoral pathology. All patients underwent oncological PD between January 2005 and February 2012. Our series was divided into two groups: Group A: Patients with a hepatic artery arising from superior mesenteric artery; and Group B: Patients without a hepatic artery arising from superior mesenteric artery. We expressed the results as mean ± standard deviation for continuous variables and percentages for qualitative variables. Statistical tests were considered significant if p < 0.05. Results: We identified 11 patients with a hepatic artery arising from superior mesenteric artery (7.3%. The most frequent variant was an aberrant right hepatic artery (n = 7, following by the accessory right hepatic artery (n = 2 and the common hepatic artery trunk arising from the superior mesenteric artery (n = 2. In 73% of cases the diagnosis of the variant was intraoperative. R0 resection was performed in all patients with a hepatic artery arising from superior mesenteric artery. There were no significant differences in the tumor resection margins and the incidence of postoperative complications. Conclusion: Oncological PD is feasible by the presence of a hepatic artery arising from superior mesenteric artery. The complexity of having it does not seem to influence in tumor resection margins, complications and survival.

  7. A COMPARATIVE STUDY OF EFFICACY AND TOLERABILITY OF GENERIC AND ORIGINAL LOW-DOSE BISOPROLOL/HYDROCHLOROTHIAZIDE COMBINATION IN PATIENTS WITH ARTERIAL HYPERTENSION OF 1-2 DEGREES. RESULTS OF CLINICAL RANDOMIZED CROSSOVER STUDY

    Directory of Open Access Journals (Sweden)

    S. Yu. Martsevich

    2015-09-01

    Full Text Available Aim. To study the clinical equivalence of the two low-dose combined drugs on the base of generic and original bisoprolol and hydrochlorothiazide (HCTZ: BISANGIL® (Ozon, Russia and LODOZ® (NYCOMED, Merck KGaA, Germany in patients with arterial hypertension (HT of 1-2 degrees.Material and methods. Patients with HT of 1-2 degrees (n=30; 11 men and 19 women; aged 62.7±10.7 years were included in open crossover randomized trial. Duration of the study for each patient was 18 weeks: two 6-week courses of active treatment with each drug and two 2-week washout periods prior to each treatment course. The sequence of treatment courses was determined by randomization. Increase in bisoprolol dose and/or amlodipine addition occurred when effect was not sufficient. Therapy effectiveness (office blood pressure (BP, heart rate and safety was monitored at visits.Results. BP reduction after 6 weeks of therapy was -21.6±11.1/10.4±11.3 mm Hg in LODOZ® group and -22.9±9.7/11.7±13.5 mm Hg in BISANGIL® group (p<0.0001 for both, intergroup differences were insignificant. Target BP after 6 weeks of therapy was achieved in 26 (87% and 28 (93% patients, respectively.Conclusion. The therapeutic equivalence of the studied fixed combinations of bisoprolol/HCTZ was demonstrated in treatment of patients with HT of 1-2 degrees.

  8. Pulsatile flow of shear-dependent fluid in a stenosed artery

    Directory of Open Access Journals (Sweden)

    Mandal Shankar Mani

    2012-01-01

    Full Text Available This paper aims to investigate the blood flow in a bell-shaped constricted rigid tube, modeled as stenosed artery. The flow is assumed to be axi-symmetric, laminar and of oscillatory type. A mathematical model of shear-thinning fluid corresponding to the shear-dependent blood viscosity (mainly due to the behavior of the red blood cells in suspension of the flowing blood is considered. The governing equations of motion are presented with the help of stream function-vorticity and are solved numerically by finite-difference technique. The shear-thinning fluid model for the flowing blood has significant contribution in the dynamics of oscillatory blood flow. The results reveal that the arterial wall shear stress reduced significantly and the peak value of the wall shear stress at the maximum area reduction is comparatively low for Newtonian fluid viscosity. The lengths of recirculating regions formed after the constriction are reduced for the shear-thinning blood viscosity model and also for its different material parameters.

  9. Finite quantum gauge theories

    Science.gov (United States)

    Modesto, Leonardo; Piva, Marco; Rachwał, Lesław

    2016-07-01

    We explicitly compute the one-loop exact beta function for a nonlocal extension of the standard gauge theory, in particular, Yang-Mills and QED. The theory, made of a weakly nonlocal kinetic term and a local potential of the gauge field, is unitary (ghost-free) and perturbatively super-renormalizable. Moreover, in the action we can always choose the potential (consisting of one "killer operator") to make zero the beta function of the running gauge coupling constant. The outcome is a UV finite theory for any gauge interaction. Our calculations are done in D =4 , but the results can be generalized to even or odd spacetime dimensions. We compute the contribution to the beta function from two different killer operators by using two independent techniques, namely, the Feynman diagrams and the Barvinsky-Vilkovisky traces. By making the theories finite, we are able to solve also the Landau pole problems, in particular, in QED. Without any potential, the beta function of the one-loop super-renormalizable theory shows a universal Landau pole in the running coupling constant in the ultraviolet regime (UV), regardless of the specific higher-derivative structure. However, the dressed propagator shows neither the Landau pole in the UV nor the singularities in the infrared regime (IR).

  10. 脉冲式及伪连续式动脉自旋标记技术静息态脑灌注对比研究%Comparative Study of Cerebral Perfusion by Using Pulsed and Pseudo Continuous Arterial Spin Labeling Techniques in Resting State

    Institute of Scientific and Technical Information of China (English)

    陈春晓; 郭超; 郑罡; 王利; 赵铁柱; 卢光明

    2013-01-01

    比较研究了脉冲式动脉自旋标记(pulsed arterial spin labeling,PASL)和伪连续式动脉自旋标记(pseudo continuous arterial spin labeling,pCASL)两种磁共振成像技术在静息态脑灌注中的应用.在静息态下,采用两种动脉自旋标记技术采集了10例健康志愿者的脑灌注数据,并计算脑血流量.两种技术的测量结果均显示,人脑默认网络中的楔前叶、角回、岛叶和后扣带回的相对脑血流量高于全脑平均灌注,而pCASL更敏感.在白质、额叶、顶叶、小脑和小脑蚓区域,pCASL和PASL测量得到的灌注值有显著性差异,除枕叶、小脑和小脑蚓外,PASL测量得到的灌注量小于pCASL.在全脑范围内,pCASL的信噪比明显高于PASL,且负灌注量很少.实验表明,pCASL可以提供比PASL更准确的测量结果.%The comparative study between pulsed arterial spin labeling (PASL) and pseudo continuous arterial spin labeling (pCASL) in resting cerebral perfusion were investigated. The PASL and pCASL data of 10 healthy subjects were acquired by a 3.0 T MR scanner during resting state, and the relative cerebral blood flows (rCBF) were then respectively quantified and analyzed. The results revealed that both techniques were able to detect the rCBF. CBFs in the precuneus, angular gyrus, insula, posterior cingulate cortex in default network were higher than the mean CBF in the whole brain, and pCASL was much more sensitive. Comparison with PASL sequence, CBFs obtained by the pCASL were significantly higher in white matter, frontal and parietal lobe, cerebellum and cerebellar vermis than that of PASL. Moreover, in the whole brain, higher SNR and less negative perfusion voxels were found in pCASL. The experimental results show that pCASL provides more accurate measurements than PASL in cerebral blood flow perfusion.

  11. Infinite to finite: An overview of finite element analysis

    OpenAIRE

    Srirekha A; Bashetty Kusum

    2010-01-01

    The method of finite elements was developed at perfectly right times; growing computer capacities, growing human skills and industry demands for ever faster and cost effective product development providing unlimited possibilities for the researching community. This paper reviews the basic concept, current status, advances, advantages, limitations and applications of finite element method (FEM) in restorative dentistry and endodontics. Finite element method is able to reveal the otherwise inac...

  12. Robust mixed finite element methods to deal with incompressibility in finite strain in an industrial framework

    International Nuclear Information System (INIS)

    Simulations in solid mechanics exhibit several difficulties, as dealing with incompressibility, with nonlinearities due to finite strains, contact laws, or constitutive laws. The basic motivation of our work is to propose efficient finite element methods capable of dealing with incompressibility in finite strain context, and using elements of low order. During the three last decades, many approaches have been proposed in the literature to overcome the incompressibility problem. Among them, mixed formulations offer an interesting theoretical framework. In this work, a three-field mixed formulation (displacement, pressure, volumetric strain) is investigated. In some cases, this formulation can be condensed in a two-field (displacement - pressure) mixed formulation. However, it is well-known that the discrete problem given by the Galerkin finite element technique, does not inherit the 'inf-sup' stability condition from the continuous problem. Hence, the interpolation orders in displacement and pressure have to be chosen in a way to satisfy the Brezzi-Babuska stability conditions when using Galerkin approaches. Interpolation orders must be chosen so as to satisfy this condition. Two possibilities are considered: to use stable finite element satisfying this requirement, or to use finite element that does not satisfy this condition, and to add terms stabilizing the FE Galerkin formulation. The latter approach allows the use of equal order interpolation. In this work, stable finite element P2/P1 and P2/P1/P1 are used as reference, and compared to P1/P1 and P1/P1/P1 formulations stabilized with a bubble function or with a VMS method (Variational Multi-Scale) based on a sub-grid-space orthogonal to the FE space. A finite strain model based on logarithmic strain is selected. This approach is extended to three and two field mixed formulations with stable or stabilized elements. These approaches are validated on academic cases and used on industrial cases. (author)

  13. Hemodynamics of left internal mammary artery bypass graft: Effect of anastomotic geometry, coronary artery stenosis, and postoperative time.

    Science.gov (United States)

    Fan, Tingting; Lu, Yuan; Gao, Yan; Meng, Jie; Tan, Wenchang; Huo, Yunlong; Kassab, Ghassan S

    2016-03-21

    Although the left internal mammary artery (LIMA) bypass graft is the best choice for surgical revascularization, its hemodynamics are still complex and can result in long-term graft failure. Here, we performed a hemodynamic analysis of the LIMA-coronary artery with end-to-side/side-to-side anastomoses based on 15 patient-specific CTA images at various postoperative periods. We hypothesize that hemodynamic patterns are determined by the interplay of LIMA geometry, anastomotic configuration, and severity of native coronary artery stenosis, which are strongly affected by the postoperative time. A 3D finite volume method with the inlet pressure wave and outlet resistance boundary conditions was used to compute the distribution of pressure and flow, from which the time-averaged wall shear stress (TAWSS), oscillation shear index (OSI), time-averaged WSS gradient (TAWSSG), and transverse WSS (transWSS) were determined. To characterize the hemodynamic environment, we defined surface area ratios of low TAWSS (≤4dynes/cm(2)), high OSI (≥0.15), TAWSSG (≥500dynes/cm(3)), and transWSS (≥6dynes/cm(2)) in the LIMA graft and at the anastomosis between LIMA graft and coronary artery. These ratios were determined by the interplay of multiple morphometric parameters in the LIMA-coronary artery, but increased with postoperative time. These findings have significant implications for understanding LIMA graft patency. PMID:26900034

  14. Usefulness of multidetector-row CT (MD-CT) for assessment of coronary artery stenosis

    International Nuclear Information System (INIS)

    Coronary arteries stenosis were evaluated in 49 cases by volume rendering (VR) and partial maximum intensity projection (partial MIP) using multidetector-row CT (MD-CT). Left main trunk (LMT) and left anterior descending artery (LAD) were less affected by cardiac pulsation artifact and presented good images. Right coronary artery (RCA) was affected by cardiac pulsation artifact and image quality was inferior as compared to left coronary artery (LCA). It is suggested that MD-CT is useful for assessment of coronary artery stenosis, especially LCA. (author)

  15. Popliteal artery entrapment syndrome.

    Science.gov (United States)

    Klooster, N J; Kitslaar, P; Janevski, B K

    1988-06-01

    Two patients with unilateral popliteal artery entrapment syndrome (PAES) are reported. The importance of diligence in angiographic diagnosis and recognition of the so-called "functional" PAES group as a separate entity are stressed. It is inferred from our material that a surgical approach for PAES is to be advocated since surgical release of the entrapment can lead to complete resolution of symptoms regardless of aetiology. PMID:2837797

  16. Popliteal artery entrapment syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Klooster, N.J.J.; Janevski, B.K.; Kitslaar, P.

    1988-06-01

    Two patients with unilateral popliteal artery entrapment syndrome (PAES) are reported. The importance of diligence in angiographic diagnosis and recognition of the so-called 'functional' PAES group as a separate entity are stressed. It is inferred from our material that a surgical approach for PAES is to be advocated since surgical release of the entrapment can lead to complete resolution of symptoms regardless of aetiology.

  17. Popliteal artery entrapment syndrome

    International Nuclear Information System (INIS)

    Two patients with unilateral popliteal artery entrapment syndrome (PAES) are reported. The importance of diligence in angiographic diagnosis and recognition of the so-called 'functional' PAES group as a separate entity are stressed. It is inferred from our material that a surgical approach for PAES is to be advocated since surgical release of the entrapment can lead to complete resolution of symptoms regardless of aetiology. (orig.)

  18. Gestational pulmonary arterial hypertension

    OpenAIRE

    Moll, Matthew; Payne, Julie G.; Tukey, Melissa H.; Farber, Harrison W.

    2015-01-01

    Pulmonary arterial hypertension (PAH) is a progressive disease marked by the irreversible pulmonary vascular changes of vasoconstriction, thrombosis, and proliferation of smooth muscle and endothelial cells. The untreated clinical course is characterized by progressive dyspnea and a median survival of less than 3 years. Many of these patients are of child-bearing age; however, pregnancy leads to physiologic changes that are particularly poorly tolerated in PAH, conferring a 30%–56% mortality....

  19. Idiopathic pulmonary arterial hypertension

    OpenAIRE

    Firth, Amy L.; Mandel, Jess; Yuan, Jason X.-J.

    2010-01-01

    Despite improved understanding of the pathobiology of pulmonary arterial hypertension (PAH), it remains a severe and progressive disease, usually culminating in right heart failure, significant morbidity and early mortality. Over the last decade, some major advances have led to substantial improvements in the management of PAH. Much of this progress was pioneered by work in animal models. Although none of the current animal models of pulmonary hypertension (PH) completely recapitulate the hum...

  20. Myocardial arterial spin labeling

    OpenAIRE

    Kober, Frank; Jao, Terrence; Troalen, Thomas; Nayak, Krishna S.

    2016-01-01

    Arterial spin labeling (ASL) is a cardiovascular magnetic resonance (CMR) technique for mapping regional myocardial blood flow. It does not require any contrast agents, is compatible with stress testing, and can be performed repeatedly or even continuously. ASL-CMR has been performed with great success in small-animals, but sensitivity to date has been poor in large animals and humans and remains an active area of research. This review paper summarizes the development of ASL-CMR techniques, c...

  1. Pulmonary arterial hypertension.

    OpenAIRE

    Montani, David; Günther, Sven; Dorfmüller, Peter; Perros, Frédéric; Girerd, Barbara; Garcia, Gilles; Jaïs, Xavier; Savale, Laurent; Artaud-Macari, Elise; Price, Laura; Humbert, Marc; Simonneau, Gérald; Sitbon, Olivier

    2013-01-01

    Pulmonary arterial hypertension (PAH) is a chronic and progressive disease leading to right heart failure and ultimately death if untreated. The first classification of PH was proposed in 1973. In 2008, the fourth World Symposium on PH held in Dana Point (California, USA) revised previous classifications. Currently, PH is devided into five subgroups. Group 1 includes patients suffering from idiopathic or familial PAH with or without germline mutations. Patients with a diagnosis of PAH should ...

  2. Mass-radius relations of white dwarfs at finite temperatures

    CERN Document Server

    Boshkayev, Kuantay; Ruffini, Remo; Zhami, Bakytzhan; Kalymova, Zhanerke; Balgimbekov, Galymdin

    2016-01-01

    We construct mass-radius relations of white dwarfs taking into account the effects of rotation and finite temperatures. We compare and contrast the theoretical mass-radius relations with observational data.

  3. Comparison of different precondtioners for nonsymmtric finite volume element methods

    Energy Technology Data Exchange (ETDEWEB)

    Mishev, I.D.

    1996-12-31

    We consider a few different preconditioners for the linear systems arising from the discretization of 3-D convection-diffusion problems with the finite volume element method. Their theoretical and computational convergence rates are compared and discussed.

  4. Renyi Entropy of the Ideal Gas in Finite Momentum Intervals

    CERN Document Server

    Bialas, A

    2003-01-01

    Coincidence probabilities of multiparticle events, as measured in finite momentum intervals for Bose and Fermi ideal gas, are calculated and compared with the exact expressions given in statistical physics.

  5. Non deterministic finite automata for power systems fault diagnostics

    Directory of Open Access Journals (Sweden)

    LINDEN, R.

    2009-06-01

    Full Text Available This paper introduces an application based on finite non-deterministic automata for power systems diagnosis. Automata for the simpler faults are presented and the proposed system is compared with an established expert system.

  6. Finite element modelling

    International Nuclear Information System (INIS)

    The Finite Element Method (FEM) is a numerical technique for finding approximate solutions to boundary value problems. While FEM is commonly used to solve solid mechanics equations, it can be applied to a large range of BVPs from many different fields. FEM has been used for reactor fuels modelling for many years. It is most often used for fuel performance modelling at the pellet and pin scale, however, it has also been used to investigate properties of the fuel material, such as thermal conductivity and fission gas release. Recently, the United Stated Department Nuclear Energy Advanced Modelling and Simulation Program has begun using FEM as the basis of the MOOSE-BISON-MARMOT Project that is developing a multi-dimensional, multi-physics fuel performance capability that is massively parallel and will use multi-scale material models to provide a truly predictive modelling capability. (authors)

  7. Nonstandard finite difference schemes

    Science.gov (United States)

    Mickens, Ronald E.

    1995-01-01

    The major research activities of this proposal center on the construction and analysis of nonstandard finite-difference schemes for ordinary and partial differential equations. In particular, we investigate schemes that either have zero truncation errors (exact schemes) or possess other significant features of importance for numerical integration. Our eventual goal is to bring these methods to bear on problems that arise in the modeling of various physical, engineering, and technological systems. At present, these efforts are extended in the direction of understanding the exact nature of these nonstandard procedures and extending their use to more complicated model equations. Our presentation will give a listing (obtained to date) of the nonstandard rules, their application to a number of linear and nonlinear, ordinary and partial differential equations. In certain cases, numerical results will be presented.

  8. Robotic coronary artery bypass for aberrant right coronary artery stenosis.

    Science.gov (United States)

    Chen, Kuan-chin Jean; Teefy, Patrick; Kiaii, Bob; Vezina, William C; Chu, Michael Wa

    2010-10-01

    Anomalous coronary arteries that course between the aorta and pulmonary artery are subject to compressive forces and can manifest angina, myocardial infarction and sudden death. The current report presents a young, female patient who presented with a short duration of severe, rapidly progressive angina despite optimal medical therapy. Combined computed tomography and myocardial perfusion scanning identified an anomalous dominant right coronary artery that appeared kinked at its origin between the aorta and main pulmonary artery. A robot-assisted right internal thoracic artery to right coronary artery bypass was performed, which was confirmed to be widely patent (FitzGibbon grade A) on routine intraoperative angiography. The procedure completely resolved the patient's angina symptoms. PMID:20931103

  9. Análise comparativa entre a vascularização arterial ventricular e do nó sinoatrial em corações de cães Comparative analysis between both ventricular and sinoatrial node arterial vascularization in heart of dogs

    Directory of Open Access Journals (Sweden)

    Caio Biasi

    2013-01-01

    Full Text Available Utilizamos nesta pesquisa 40 corações de cães adultos, machos e fêmeas, de idades variadas, que não portavam nenhuma afecção cardíaca. Os corações tiveram as artérias coronárias injetadas, separadamente, com Neoprene Látex 450, corado com pigmento vermelho, e posteriormente dissecados. Em todas estas preparações verificamos que na vascularização dos ventrículos predominava a artéria coronária esquerda que fornecia os ramos interventriculares paraconal e subsinuoso. Já, a região ocupada pelo nó sinoatrial ficava mais frequentemente (17 vezes, 42,5% na dependência do ramo proximal atrial esquerdo ou de colateral deste vaso, oriundo do ramo circunflexo esquerdo, ou deste vaso associado ao ramo distal atrial direito (8 vezes, 20%, procedente do ramo circunflexo direito. Com menor frequência (14 vezes, 30%, a área tomada pelo nó sinoatrial, encontramos apenas colaterais do ramo circunflexo direito, mais exatamente somente o ramo distal atrial direito (10 vezes, 25%, apenas o ramo proximal atrial direito (3 vezes, 7,5% ou ainda exclusivamente o ramo intermédio atrial direito (1 vez, 2,5%. Em um único caso (1 vez, 2,5% no território do nó sinoatrial observamos apenas colateral do ramo circunflexo esquerdo, isto é o ramo distal atrial esquerdo. A análise destes resultados permite concluir, que nesta espécie não existe qualquer tipo de relação entre o tipo de vascularização dos ventrículos e a irrigação do nó sinoatrial. Sendo assim, considerar os ramos ventriculares isoladamente não é suficiente para um entendimento clínico-cirúrgico aplicado, uma vez que os ramos atriais apresentam uma importante contribuição para a vascularização do nó sinoatrial.We analyzed 40 hearts of adult dogs, males and females of different ages, without cardiac disease. The hearts had the coronary arteries inject using Neoprene Latex 450, colored with red pigment, and which was then dissected. In the ventricular

  10. Neoclassical toroidal plasma viscosity with effects of finite banana width for finite aspect ratio tokamaks

    Science.gov (United States)

    Shaing, K. C.; Sabbagh, S. A.

    2016-07-01

    Theory for neoclassical toroidal plasma viscosity has been developed to model transport phenomena, especially, toroidal plasma rotation for tokamaks with broken symmetry. Theoretical predictions are in agreement with the results of the numerical codes in the large aspect ratio limit. The theory has since been extended to include effects of finite aspect ratio and finite plasma β. Here, β is the ratio of the plasma thermal pressure to the magnetic field pressure. However, there are cases where the radial wavelength of the self-consistent perturbed magnetic field strength B on the perturbed magnetic surface is comparable to the width of the trapped particles, i.e., bananas. To accommodate those cases, the theory for neoclassical toroidal plasma viscosity is further extended here to include the effects of the finite banana width. The extended theory is developed using the orbit averaged drift kinetic equation in the low collisionality regimes. The results of the theory can now be used to model plasma transport, including toroidal plasma rotation, in real finite aspect ratio, and finite plasma β tokamaks with the radial wavelength of the perturbed symmetry breaking magnetic field strength comparable to or longer than the banana width.

  11. COMPARATIVE STUDY OF NEW DRUG OF LONG ACTING METOPROLOL TARTRATE - EGILOK RETARD AND ORIGINAL DRUG OF METOPROLOL SUCCINATE – BETALOC ZOK IN PATIENTS WITH MILD TO MODERATE ARTERIAL HYPERTENSION

    Directory of Open Access Journals (Sweden)

    J. V. Lukina

    2015-12-01

    Full Text Available Aim. To study efficiency and safety of new drug of long acting metoprolol tartrate, “Egilok retard” (ER in patients with mild to moderate arterial hypertension (AH in comparison with the original drug of metoprolol succinat, “Betaloc ZOK” (BZ, possibility of reaching target blood pressure (BP level with treatment with each drug.Material and methods. 30 patients (11 men and 19 women with mild to moderate AH took part in randomized, open, cross over study. Previous antihypertensive treatment had been canceled for all the patients 10-14 days before the study started. Each patient by turns was treated during 6 weeks with ER and BZ 50-100 mg daily. After cancellation of the previous antihypertensive therapy, BZ and ER were prescribed (according to the randomization table in dose 50 mg daily. Drugs were taken once per day. 29 patients completed therapy with the first drug of randomization, 25 patients – with the second. After 2 weeks efficiency of treatment was assessed by target BP level achievement (< 140/90 mmHg. If efficiency of beta-adrenoblocker (BB was not sufficient, the dose of the drug was doubled to 100 mg daily, if target level was reached – the dose remained unchanged. Treatment with the settled dose was held within next 4 weeks. After 6-week treatment with the first randomized drug antihypertensive therapy was canceled for 10-14 days depending on the BB dose. At each visit office BP and heart rate were assessed, EKG was registered. Side-effects were registered according to the self-control diary, questionnaire results, examination and EKG data.Results. After 6-week treatment with ER and BZ average level of systolic BP reduced by 15,7 and 15,2 mmHg, of diastolic BP – by 8,0 and 4,5 mmHg, heart rate – by 4,1 and 4,3 beat/min respectively. Differences between antihypertensive and heart rate lowering effect of the studied drugs were not significant. Target BP level with treatment with both drugs was reached in approximately

  12. Umbilical artery tone in maternal obesity

    Directory of Open Access Journals (Sweden)

    Glavey Siobhan V

    2009-01-01

    Full Text Available Abstract Background The increasing prevalence of obesity constitutes a major health problem in obstetrics with implications for feto-maternal growth and wellbeing. This study investigated and compared the contractile properties of umbilical arteries excised from obese women, with those excised from women with a normal body mass index (BMI. Methods Sections of umbilical artery were obtained from umbilical cord samples immediately after delivery and mounted for isometric recording in organ tissue baths under physiological conditions. Cumulative additions of 5-Hydroxytryptamine (5-HT and Prostaglandin F-2alpha (PgF2alpha were added in the concentration range of 1 nmol/L to 10 micromol/L. Control vessels were exposed to Krebs physiological salt solution (PSS only. The resultant effects of each drug addition were measured using the Powerlab hardware unit. Results 5-HT exerted a significant effect on human umbilical artery tone at concentrations of 100 nmol/L, 1 micromol/L, and 10 micromol/L in normal (n = 5; P 0.05. Conclusion These findings support the hypothesis that endogenous regulation of umbilical artery tone is altered in association with maternal obesity. This may be linked to the cardiovascular effects of secretory products of adipose tissue, with implications for the feto-maternal circulation.

  13. Drug-eluting stents in renal artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Zaehringer, M. [Marienhospital Stuttgart, Department of Radiology, Stuttgart (Germany); Pattynama, P.M.T. [Erasmus MC-University Medical Center Rotterdam, Rotterdam (Netherlands); Talen, A. [genae associates nv, Antwerp (Belgium); Sapoval, M. [Hopital Europeen Georges Pompidou, Service de Radiologie Cardio-Vasculaire, Paris (France); Inserm U 780 epidemiologie Cardio Vasculaire, Paris (France)

    2008-04-15

    Because of higher acute and long-term success rates compared with balloon angioplasty alone, percutaneous stent implantation has become an accepted therapy for the treatment of atherosclerotic renal artery stenosis. Restenosis rates after successful renal stent placement vary from 6 up to 40%, depending on the definition of restenosis, the diameter of the treated vessel segment and comorbidities. The safety and efficacy of drug-eluting stents for the treatment of renal-artery stenosis is poorly defined. The recently published GREAT study is the only prospective study, comparing bare-metal and sirolimus-coated low profile stent systems in renal artery stenosis, showing a relative risk reduction of angiographic binary in-stent restenosis by 50%. This is an opinion paper on indications, current treatment options and restenosis rates following renal artery stenting and the potential use of drug-eluting stents for this indication. (orig.)

  14. Cranial and caudal mesenteric arteries of the paca (Cuniculus paca, L. 1766

    Directory of Open Access Journals (Sweden)

    Isabela Cristina de Souza Marques

    2013-03-01

    Full Text Available The paca (Cuniculus paca, Linnaeus, 1766 is a medium-sized rodent that occurs in Brazil; however, there is little information regarding its morphology. The goal of this study was to describe the origin and branching of the cranial and caudal mesenteric arteries of this rodent in order to contribute to comparative anatomy studies. Ten animals (males and females were used. After death, their thoracic inlet was opened between the fourth and sixth ribs to expose the thoracic aorta, which was cannulated caudally. A stained, neoprene latex solution was then injected, in order to fill the arterial system, and the preparations were fixed in a 10% aqueous formalin solution for over 72h. The fixed specimens were dissected to identify the cranial and caudal mesenteric arteries. The cranial mesenteric artery started at the abdominal aorta, caudally to the celiac artery, and originated in the following arterial branches: caudal pancreatic duodenal, pancreatic, jejunal, ileum colic and cecal. The origin of the caudal mesenteric artery occurred next to the end of abdominal aorta and this vessel issued the left colic artery and cranial rectal artery from which the sigmoid arteries initiated. It was found that there was little difference in the branching pattern of the arteries compared to other rodents and domestic mammals.

  15. Intracranial arterial anatomy: evaluation by computed tomography angiography; Anatomia arterial intracraniana: avaliacao por angiotomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Regattieri, Neysa Aparecida Tinoco, E-mail: neysa@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Haetinger, Rainer Guilherme; Liberti, Edson Aparecido [Universidade de Sao Paulo (ICB III/USP), SP (Brazil). Inst. de Ciencias Biomedicas; Piske, Ronie Leo [Hospital Beneficencia Portuguesa de Sao Paulo, SP (Brazil)

    2010-07-01

    By many decades, the intracranial arteries study was realized exclusively by angiography through selective arterial catheterization. Nowadays, with the technologic evaluation of computerized tomography devices with multi detectors allowing acquisitions with even more thinner slices, higher speed and better resolution, it had appeared a new modality of investigation: the computed tomography angiography, less invasive and with minor morbidity than conventional arteriography. Many studies in the literature have been analyzing the sensibility of the new method for the detection of intracranial aneurysms and comparing them with the conventional arteriography. There is a necessity to recognize the normal intracranial arterial anatomy and its variations using images obtained from multiplanar reformations, in order to give important information for surgeries strategies, such as wall calcifications, aneurismatic neck position and relationships with surrounding anatomical structures. (author)

  16. Arterial responses during migraine headache

    DEFF Research Database (Denmark)

    Iversen, Helle Klingenberg; Nielsen, T H; Olesen, J;

    1990-01-01

    The superficial temporal artery has been thought to be the main focus of pain during migraine attacks, but its diameter has never been measured directly. The use of a new, high-resolution ultrasound machine to measure arterial size in 25 migraine patients with unilateral head pain showed that the...... lumen was wider on the painful than on the non-painful side during a migraine attack. The diameters of both radial arteries and the temporal artery on the non-painful side were smaller during than between attacks. The generalised vasoconstriction was not shared by the temporal artery on the affected...... side, which suggests a local vasodilatory response. The findings suggest that cephalic arteries may play a role in migraine pathogenesis....

  17. True aneurysm of brachial artery.

    Science.gov (United States)

    Hudorović, Narcis; Lovričević, Ivo; Franjić, Dario Bjorn; Brkić, Petar; Tomas, Davor

    2010-10-01

    True upper extremity peripheral artery aneurysms are a rarely encountered arterial disorder. Following computer-tomography angiographic (CT-a) imaging examination, true saccular aneurysm, originating from the left brachial artery was diagnosed in the 77-year-old female without history of trauma. The aneurysm was resected by surgical intervention, and primary repair of the brachial artery was performed by interposition of a part of great saphenous vein harvested from the left groin and creation of two end-to-end anastomoses between interposition graft and previously resected part of brachial artery. No complication was observed during the follow-up. Surgical intervention for upper extremity aneurysms should be initiated without delay. Factors combined with minimal morbidity associated with repair suggest that surgical repair should be performed routinely for true upper extremity arterial aneurysms. PMID:20865459

  18. A unified approach to Mimetic Finite Difference, Hybrid Finite Volume and Mixed Finite Volume methods

    OpenAIRE

    Droniou, Jerome; Eymard,, Robert; Gallouët, Thierry; Herbin, Raphaele

    2008-01-01

    International audience We investigate the connections between several recent methods for the discretization of ani\\-so\\-tropic heterogeneous diffusion operators on general grids. We prove that the Mimetic Finite Difference scheme, the Hybrid Finite Volume scheme and the Mixed Finite Volume scheme are in fact identical up to some slight generalizations. As a consequence, some of the mathematical results obtained for each of the method (such as convergence properties or error estimates) may ...

  19. HISTOLOGICAL STUDY OF MEDIUM SIZED ARTERIES OF NECK IN RELATION WITH THEIR PULSE PRESSURE AND PULSATORY POWER

    Directory of Open Access Journals (Sweden)

    Prerana

    2014-11-01

    Full Text Available : INTRODUCTION: There are several studies on the microstructure of main arteries of the body but limited have been dealt with the neck arteries. It has been mentioned that the vascular pathologies like the thrombo-embolism, atherosclerosis and infarction are common in the branches of vertebral and internal carotid artery as compared to the branches of external carotid artery. OBJECTIVE: To study the histological structure of the 3 medium sized arteries of neck namely external carotid, internal carotid and vertebral artery, calculation of their mean pulse pressure and pulsatory power and to find any association between them if present. METHOD: Fresh samples of external carotid, internal carotid and vertebral artery each measuring 10mm in length were taken from five cadavers and prepared for histological examination under microscope using orcein and H&E stain. The mean pressure and pulsatory power of these arteries were calculated by taking the measurements such as wall thickness, lumen circumference, arterial wall area, and smooth muscle fibre density in tunica media in that arterial segment. RESULT: The pulsatory power of external carotid artery, internal carotid artery and vertebral artery is found to be 120, 273.3, 400 Joules /heart beat and the mean pressure is 17.1 mm Hg, 27.3 mm Hg and 33.3 mm Hg respectively. CONCLUSION: The thickness of tunica media of an artery is directly proportional to its pulsatory power. The mean pulse pressure, pulsatory power as well the number of smooth muscles fibres in tunica media are more in internal carotid artery and vertebral artery in comparison to external carotid artery. It may be a very important reason why vascular pathologies are less common in branches of external carotid as compare to internal carotid and vertebral artery.

  20. Hemodynamics in stented vertebral artery ostial stenosis based on computational fluid dynamics simulations.

    Science.gov (United States)

    Qiao, Aike; Dai, Xuan; Niu, Jing; Jiao, Liqun

    2016-08-01

    Hemodynamic factors may affect the potential occurrence of in-stent restenosis (ISR) after intervention procedure of vertebral artery ostial stenosis (VAOS). The purpose of the present study is to investigate the influence of stent protrusion length in implantation strategy on the local hemodynamics of the VAOS. CTA images of a 58-year-old female patient with posterior circulation transient ischemic attack were used to perform a 3D reconstruction of the vertebral artery. Five models of the vertebral artery before and after the stent implantation were established. Model 1 was without stent implantation, Model 2-5 was with stent protruding into the subclavian artery for 0, 1, 2, 3 mm, respectively. Computational fluid dynamics simulations based on finite element analysis were employed to mimic the blood flow in arteries and to assess hemodynamic conditions, particularly the blood flow velocity and wall shear stress (WSS). The WSS and the blood flow velocity at the vertebral artery ostium were reduced by 85.33 and 35.36% respectively after stents implantation. The phenomenon of helical flow disappeared. Hemodynamics comparison showed that stent struts that protruded 1 mm into the subclavian artery induced the least decrease in blood speed and WSS. The results suggest that stent implantation can improve the hemodynamics of VAOS, while stent struts that had protruded 1 mm into the subclavian artery would result in less thrombogenesis and neointimal hyperplasia and most likely decrease the risk of ISR. PMID:26691981

  1. Analysis of conforming and nonconforming quadrilateral finite element methods for the Helmholtz equation

    OpenAIRE

    LEE, Ki-tak; HA, Taeyoung; SHEEN, Dongwoo

    2007-01-01

    In this paper we analyze numerical dispersion relation of some conforming and nonconforming quadrilateral finite elements. The elements employed in this analysis are the standard $Q_1$ conforming finite element, the DSSY nonconforming element [5] and the $P_1$-nonconforming quadrilateral finite element [14]. Several aspects of comparative analyses of the above three elements for two or three dimensional problems are shown.

  2. Triple spontaneous cervical artery dissection

    International Nuclear Information System (INIS)

    A 39-year-old healthy man had several transient ischaemic attacks suggesting left internal carotid artery (ICA) occlusion. There were no vascular risk factors and no preceding trauma. Colour-coded duplex sonography suggested a pseudo-occlusion of the left ICA, and cerebral angiography demonstrated dissection of the left ICA and both vertebral arteries. Angiography 6 months later was completely normal. This underlines the importance of four vessel angiography in young patients with dissections of cervical arteries. (orig.)

  3. The right hepatic artery syndrome

    Institute of Scientific and Technical Information of China (English)

    Kazumi Miyashita; Katsuya Shiraki; Takeshi Ito; Hiroki Taoka; Takeshi Nakano

    2005-01-01

    Various benign and malignant conditions could cause biliary obstruction. Compression of extrahepatic bile duct (EBD) by right hepatic artery was reported as a right hepatic artery syndrome but all cases were compressed EBD from stomach side. Our case compressed from dorsum was not yet reported, so it was thought to be a very rare case. We present here the first case of bile duct obstruction due to the compression of EBD from dorsum by right hepatic artery.

  4. Non-invasive diagnostic methods of intracranial arteries

    OpenAIRE

    Ramgren, Birgitta

    2014-01-01

    Aims of this thesis were to compare the agreement of different magnetic resonance angiography(MRA) techniques and digital subtraction angiography (DSA) in follow-up of intracranial aneurysms treated with coils in order to select the best MRA method, to evaluate the impact of increased iodine concentration in contrast medium and decreased tube voltage on arterial attenuation and image quality in computed tomography angiography (CTA) of intracranial arteries, and finally to evaluate the diag...

  5. An Ultrastructural Analysis of Collagen in Tissue Engineered Arteries

    OpenAIRE

    Dahl, Shannon L. M.; Vaughn, Megann E.; Niklason, Laura E.

    2007-01-01

    Collagen is the structural molecule that is most correlated with strength in blood vessels. In this study, we compared the properties of collagen in engineered and native blood vessels. Transmission electron microscopy (TEM) was used to image sections of engineered and native arteries. Band periodicities of engineered and native collagen fibrils indicated that spacing between collagen molecules was similar in engineered and native tissues. Engineered arteries, however, had thinner collagen fi...

  6. Spatiotemporal Changes Posttreatment in Peripheral Arterial Disease

    OpenAIRE

    Myers, Sara A.; Huben, Neil B.; Yentes, Jennifer M.; McCamley, John D.; Lyden, Elizabeth R.; Pipinos, Iraklis I.; Johanning, Jason M.

    2015-01-01

    Accumulating evidence suggests revascularization of peripheral arterial disease (PAD) limbs results in limited improvement in functional gait parameters, suggesting underlying locomotor system pathology. Spatial and temporal (ST) gait parameters are well studied in patients with PAD at baseline and are abnormal when compared to controls. The purpose of this study was to systematically review and critically analyze the available data on ST gait parameters before and after interventions. A full...

  7. Finite element model of needle electrode sensitivity

    Science.gov (United States)

    Høyum, P.; Kalvøy, H.; Martinsen, Ø. G.; Grimnes, S.

    2010-04-01

    We used the Finite Element (FE) Method to estimate the sensitivity of a needle electrode for bioimpedance measurement. This current conducting needle with insulated shaft was inserted in a saline solution and current was measured at the neutral electrode. FE model resistance and reactance were calculated and successfully compared with measurements on a laboratory model. The sensitivity field was described graphically based on these FE simulations.

  8. Arterial mapping of lower limbs

    International Nuclear Information System (INIS)

    A bibliographic review is realized in the arterial mapping of lower limbs by ultrasonographic. The physical properties of the Doppler effect applied to diagnostic ultrasound are described. The anatomical characteristics of the general arterial system and specifically of the lower limbs arterial system are mentioned. Pathologies of the ischemic arterial disease of lower limbs are explained. The study characteristics of lower limbs arterial mapping are documented to determine its importance as appropriate method for the assessment of lower limb ischemia. An adequate arterial mapping of lower limbs is recognized in atherosclerotic ischemic disease as a reliable initial method alternative to arteriography. Arteriography is considered as reference pattern for therapeutic decision making in patients with critical ischemia of the lower limbs. Non-invasive methods to assess the arterial system of lower limbs has evidenced the advantages of the arterial mapping with Doppler, according to the consulted literature. The combination morphological and hemodynamic information has been possible and a map of the explored zone is made. The arterial mapping by ultrasonography has offered similar reliability to angiography

  9. An efficient finite element solution for gear dynamics

    International Nuclear Information System (INIS)

    A finite element formulation for the dynamic response of gear pairs is proposed. Following an established approach in lumped parameter gear dynamic models, the static solution is used as the excitation in a frequency domain solution of the finite element vibration model. The nonlinear finite element/contact mechanics formulation provides accurate calculation of the static solution and average mesh stiffness that are used in the dynamic simulation. The frequency domain finite element calculation of dynamic response compares well with numerically integrated (time domain) finite element dynamic results and previously published experimental results. Simulation time with the proposed formulation is two orders of magnitude lower than numerically integrated dynamic results. This formulation admits system level dynamic gearbox response, which may include multiple gear meshes, flexible shafts, rolling element bearings, housing structures, and other deformable components.

  10. Design of eddy current coil using finite element model

    International Nuclear Information System (INIS)

    Eddy current signal evaluation is based on the relationship between signal shape and defect characteristics. As a numerical approach finite element model can be useful to eddy current phenomena. Using a finite element program for axi-symmetric and two-dimensional geometry, the effect of coil distance and width to the eddy current signal shapes were investigated. Various coils were fabricated and actual eddy current signals were compared with the finite element model calculations. As either coil distance or coil width increases, the signal shape changes from differential-like to absolute-like. The signals from the finite element analysis were well matched to the experimental results. The finite element analysis can be a useful tool for optimization of design parameters for eddy current coil, such as coil dimension, operating frequency, materials properties, and defect type, etc.

  11. Reactor kinetic formulation using the finite element method

    International Nuclear Information System (INIS)

    This research has the objective of solving the spatial Kinetic equations for two energy groups using the finite element method. In the methodology, was applied the direct method, such that matrix equations coefficients from spatial discretization was generated by finite element method. The formulation of the time-dependent problem was obtained by analytical integration of precursor concentration equation and using the Euler implicit scheme in the dynamic diffusion problem. A 2D example of a reactor static diffusion problem was solved using a linear triangular finite element. This solution was compared with the numerical benchmark solution, found in the literature, and the numerical results calculated by the finite difference methods. This comparison shows the capacity of the finite element method to obtain a precise solution. (author)

  12. On stochastic finite difference schemes

    OpenAIRE

    Gyongy, Istvan

    2013-01-01

    Finite difference schemes in the spatial variable for degenerate stochastic parabolic PDEs are investigated. Sharp results on the rate of $L_p$ and almost sure convergence of the finite difference approximations are presented and results on Richardson extrapolation are established for stochastic parabolic schemes under smoothness assumptions.

  13. Finite strain discrete dislocation plasticity

    NARCIS (Netherlands)

    Deshpande, VS; Needleman, A; Van der Giessen, E

    2003-01-01

    A framework for carrying out finite deformation discrete dislocation plasticity calculations is presented. The discrete dislocations are presumed to be adequately represented by the singular linear elastic fields so that the large deformations near dislocation cores are not modeled. The finite defor

  14. Stabilized Finite Elements with Matlab

    OpenAIRE

    Asensio, M. I.; A. Russo

    2002-01-01

    The purpose of this note is to explain the MATLAB code developed to solve an advection diffusion-reaction problem, with different Finite Element Methods: Standard Galerkin [7], Streamline Upwind/ Petrov-Galerkin (SUPG) [6], Unsual Stabilized [8, 9] and Residual-Free Bubbles [3, 4, 5], for both linear (P1) (see [1]) and quadratic (P2) (see [2]) triangular finite elements.

  15. The Finite-State Playground

    Science.gov (United States)

    Hammond, Michael

    2008-01-01

    Finite-state methods are finding ever increasing use among linguists as a way of modeling phonology and morphology and as a method for manipulating and modeling text. This paper describes a suite of very simple finite-state tools written by the author that can be used to investigate this area and that can be used for simple analysis.

  16. Solution of Finite Element Equations

    DEFF Research Database (Denmark)

    Krenk, Steen

    An important step in solving any problem by the finite element method is the solution of the global equations. Numerical solution of linear equations is a subject covered in most courses in numerical analysis. However, the equations encountered in most finite element applications have some special...

  17. Role of KATP channels in the regulation of rat dura and pia artery diameter

    DEFF Research Database (Denmark)

    Gozalov, A.; Petersen, K.A.; Mortensen, C.;

    2005-01-01

    The aim of the present study was to examine the effect of K(ATP) channel openers pinacidil and levcromakalim on rat dural and pial arteries as well as their inhibition by glibenclamide. We used an in-vivo genuine closed cranial window model and an in-vitro organ bath. Glibenclamide alone reduced...... the dural but not the pial artery diameter compared with controls. Intravenous pinacidil and levcromakalim induced dural and middle cerebral artery relaxation that was significantly attenuated by glibenclamide. In conclusion, K(ATP) channel openers induce increasing diameter/relaxation of dural and...... pial arteries after intravenous infusion in vivo and on isolated arteries in vitro. Furthermore, dural arteries were more sensitive to K(ATP) channel openers than pial arteries....

  18. Massively Parallel Finite Element Programming

    KAUST Repository

    Heister, Timo

    2010-01-01

    Today\\'s large finite element simulations require parallel algorithms to scale on clusters with thousands or tens of thousands of processor cores. We present data structures and algorithms to take advantage of the power of high performance computers in generic finite element codes. Existing generic finite element libraries often restrict the parallelization to parallel linear algebra routines. This is a limiting factor when solving on more than a few hundreds of cores. We describe routines for distributed storage of all major components coupled with efficient, scalable algorithms. We give an overview of our effort to enable the modern and generic finite element library deal.II to take advantage of the power of large clusters. In particular, we describe the construction of a distributed mesh and develop algorithms to fully parallelize the finite element calculation. Numerical results demonstrate good scalability. © 2010 Springer-Verlag.

  19. Artery Remodeling Under Axial Twist in Three Days Organ Culture.

    Science.gov (United States)

    Wang, Guo-Liang; Xiao, Yangming; Voorhees, Andrew; Qi, Ying-Xin; Jiang, Zong-Lai; Han, Hai-Chao

    2015-08-01

    Arteries often endure axial twist due to body movement and surgical procedures, but how arteries remodel under axial twist remains unclear. The objective of this study was to investigate early stage arterial wall remodeling under axial twist. Porcine carotid arteries were twisted axially and maintained for three days in ex vivo organ culture systems while the pressure and flow remained the same as untwisted controls. Cell proliferation, internal elastic lamina (IEL) fenestrae shape and size, endothelial cell (EC) morphology and orientation, as well as the expression of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, and tissue inhibitor of metalloproteinase-2 (TIMP-2) were quantified using immunohistochemistry staining and immunoblotting. Our results demonstrated that cell proliferation in both the intima and media were significantly higher in the twisted arteries compared to the controls. The cell proliferation in the intima increased from 1.33 ± 0.21% to 7.63 ± 1.89%, and in the media from 1.93 ± 0.84% to 8.27 ± 2.92% (p culture, a decrease from the initial 15.58 ± 1.29 degrees. These results demonstrate that axial twist can stimulate artery remodeling. These findings complement our understanding of arterial wall remodeling under mechanical stress resulting from pressure and flow variations. PMID:25503524

  20. Comparison of Coronary Artery Bypass Grafting with Percutaneous Coronary Intervention for Unprotected Left Main Coronary Artery Disease

    OpenAIRE

    Kawecki, Damian; Morawiec, Beata; Fudal, Marcin; Milejski, Wojciech; Jacheć, Wojciech; Nowalany-Kozielska, Ewa

    2011-01-01

    Purpose Coronary artery bypass grafting (CABG) is the optimal treatment option for left main coronary artery disease (LMCAD). However, LMCAD remains a constant topic of discussion between cardiac surgeons and interventional cardiologists. The aim of this study was to assess the efficacy of LMCAD treatments by comparing the mid-term outcomes of CABG and percutaneous coronary intervention (PCI) using bare metal stents or drug-eluting stents (DESs). Materials and Methods The study population was...

  1. Finite-g Strings

    CERN Document Server

    Vicedo, Benoit

    2008-01-01

    In view of one day proving the AdS/CFT correspondence, a deeper understanding of string theory on certain curved backgrounds such as AdS_5xS^5 is required. In this dissertation we make a step in this direction by focusing on RxS^3. It was discovered in recent years that string theory on AdS_5xS^5 admits a Lax formulation. However, the complete statement of integrability requires not only the existence of a Lax formulation, but also that the resulting integrals of motion are in pairwise involution. This idea is central to the first part of this thesis. Exploiting this integrability we apply algebro-geometric methods to string theory on RxS^3 and obtain the general finite-gap solution. The construction is based on an invariant algebraic curve previously found in the AdS_5xS^5 case. However, encoding the dynamics of the solution requires specification of additional marked points. By restricting the symplectic structure of the string to this algebro-geometric data we derive the action-angle variables of the syste...

  2. Mimetic finite difference method

    Science.gov (United States)

    Lipnikov, Konstantin; Manzini, Gianmarco; Shashkov, Mikhail

    2014-01-01

    The mimetic finite difference (MFD) method mimics fundamental properties of mathematical and physical systems including conservation laws, symmetry and positivity of solutions, duality and self-adjointness of differential operators, and exact mathematical identities of the vector and tensor calculus. This article is the first comprehensive review of the 50-year long history of the mimetic methodology and describes in a systematic way the major mimetic ideas and their relevance to academic and real-life problems. The supporting applications include diffusion, electromagnetics, fluid flow, and Lagrangian hydrodynamics problems. The article provides enough details to build various discrete operators on unstructured polygonal and polyhedral meshes and summarizes the major convergence results for the mimetic approximations. Most of these theoretical results, which are presented here as lemmas, propositions and theorems, are either original or an extension of existing results to a more general formulation using polyhedral meshes. Finally, flexibility and extensibility of the mimetic methodology are shown by deriving higher-order approximations, enforcing discrete maximum principles for diffusion problems, and ensuring the numerical stability for saddle-point systems.

  3. [The single coronary artery].

    Science.gov (United States)

    Godart, F; Berzin, B; Rihani, R; Pecheux, M; Dutoit, A

    1992-04-01

    Single coronary artery is a fairly rare entity which may nevertheless be found in 0.4 per cent of coronary arteriograms. The authors report 3 cases seen in 2 departments of cardiology. In each patient, despite the existence of definite cardiovascular risk factors, this distribution was a factor worsening coronary ischemia, leading to complete thrombosis in one case. Although most often a chance discovery, a review of the literature justifies the attribution to this anomaly of the onset of angina, infarction or even sudden death. PMID:1642437

  4. Patent arterial duct

    OpenAIRE

    Martin Robin P; Elmasry Ola A; Forsey Jonathan T

    2009-01-01

    Abstract Patent arterial duct (PAD) is a congenital heart abnormality defined as persistent patency in term infants older than three months. Isolated PAD is found in around 1 in 2000 full term infants. A higher prevalence is found in preterm infants, especially those with low birth weight. The female to male ratio is 2:1. Most patients are asymptomatic when the duct is small. With a moderate-to-large duct, a characteristic continuous heart murmur (loudest in the left upper chest or infraclavi...

  5. Morphologic expression of the left coronary artery in pigs. An approach in relation to human heart

    Directory of Open Access Journals (Sweden)

    Fabian Alejandro Gómez

    2014-04-01

    Full Text Available Introduction: In spite of its importance as an experimental model, the information on the left coronary artery in pigs is sparse. Objective: To determine the morphologic features of the left coronary artery in pigs. Methods: We evaluated 158 pig hearts. The left coronary artery was perfused with synthetic resin after their ostia had been catheterized. Diameters and courses of the vascular beds were measured with an electronic caliper (Mitutoyo(r. Results: The diameter of left coronary artery was 6.98 ± 1.56 mm and its length was 3.51±0.99 mm. It was found to end up by bifurcating itself into the anterior interventricular artery and the circumflex artery in 79% of the cases, and by trifurcating in 21% of the cases, with the presence of the diagonal artery. The anterior interventricular artery ended up at the apex in 79.7% of the cases, and the circumflex artery at the posterior aspect of the left ventricle in 64% of the case, this artery never reached the posterior interventricular sulcus. An anastomosis between the terminal branches of the anterior interventricular artery and the posterior interventricular artery was found in 7.6% of the specimens. The antero-superior branch of the anterior interventricular artery occurred in 89.9% of the hearts. A left marginal branch was observed in 87.9% of the cases with a diameter of 2.25±0.55 mm. Conclusion: Compared with humans, pigs have shorter left coronary artery trunks and branches; even the circumflex artery never reaches the posterior interventricular sulcus. Our findings are useful for the design of experimental hemodynamic and procedural models.

  6. Cadaveric study: study of lateral circumflex femoral arterial origin in Rajkot

    Directory of Open Access Journals (Sweden)

    Pradip Rameshbhai Chauhan

    2015-05-01

    Full Text Available Background: Lateral circumflex femoral artery contributes cruciate, trochanteric and knee joint anastomosis. In addition Lateral circumflex femoral artery flaps are used for the reconstruction of large tissue loss in the head and neck region, aortopopliteal bypass, coronary artery bypass grafting and extracranial intracranial bypass surgery. This work was carried out (a to study the origin of lateral circumflex femoral artery and (b to measure and compare (between male and female the circumference at its origin. Methods: In this cross sectional study, 51 femoral triangles from 26 (18 male and 08 female human adult cadavers were dissected and studied at P.D.U. government medical college, Rajkot, Gujarat. Site of origin of lateral circumflex femoral artery was identified and noted. The distance of origin of the artery from the origin of profunda femoris artery was measured and noted. Circumference at the level of origin was measured and diameter was calculated. Collected data was analysed by standard statistical formulas with the help of Microsoft excel 2013 and Epi info 7TM software. Results: 90.19% lateral circumflex femoral arteries originated from the profunda femoris artery and remaining 9.81% from the femoral artery. The mean distance of origin of the artery from the origin of profunda femoris artery was 18.44 mm. Lateral circumflex femoral artery circumference and diameter were significantly different between male and female (95% confidence interval, P <0.05. Conclusion: In this presented study maximum distance of origin of the artery from the origin was 65 mm while minimum distance of origin was 6 mm. In addition difference in circumference of the artery was statistically significant. [Int J Res Med Sci 2015; 3(5.000: 1066-1069

  7. Parent Artery Occlusion for Posterior Cerebral Artery Aneurysms

    OpenAIRE

    Hoya, K.; Nagaishi, M.; Yoshimoto, Y.; Morikawa, E.; H. Takahashi(NASA Goddard Space Flight Center, Greenbelt, USA)

    2006-01-01

    We review four cases of posterior cerebral artery (PCA) aneurysm, of which three showed intolerance of parent artery occlusion. In two, balloon test occlusion (BTO) indicated poor opaci- fication of the PCA branches from the anastomoses, and therefore, permanent occlusion was not attempted.

  8. Dual anterior descending coronary artery associated with coronary artery disease

    Directory of Open Access Journals (Sweden)

    Siqueira Luciane da L. V.

    2003-01-01

    Full Text Available The patient is a male with risk factors for coronary artery disease, who was referred for cardiac catheterization after acute myocardial infarction in the inferior wall. The patient underwent transluminal coronary angioplasty in the right coronary artery with successful stent implantation.

  9. Screening asymptomatic patients with diabetes for unknown coronary artery disease: Does it reduce risk? An open-label randomized trial comparing a strategy based on exercise testing aimed at revascularization with management based on pharmacological/behavioural treatment of traditional risk factors. DADDY-D Trial (Does coronary Atherosclerosis Deserve to be Diagnosed and treated early in Diabetics?)

    OpenAIRE

    Romano Stefania; Pellegrini Elisa; Cappelli Carlo; Tosoni Giandomenico; Cavani Rita; Magnavacchi Paolo; Tondi Stefano; Giovanardi Paolo; Messora Roberto; Turrini Fabrizio; Baldini Augusto; Zennaro Romeo; Bondi Marco

    2009-01-01

    Abstract Background Coronary artery disease is the leading cause of morbidity and mortality in patients with type 2 diabetes. Screening for asymptomatic coronary artery disease with treatment by means of revascularization seems to be an appealing option for prevention. The utility of such a strategy has never been challenged in a randomized trial. Methods/Design In the present study a cohort of diabetic patients without any symptoms and without known coronary artery disease will be screened a...

  10. Finite element and finite difference methods in electromagnetic scattering

    CERN Document Server

    Morgan, MA

    2013-01-01

    This second volume in the Progress in Electromagnetic Research series examines recent advances in computational electromagnetics, with emphasis on scattering, as brought about by new formulations and algorithms which use finite element or finite difference techniques. Containing contributions by some of the world's leading experts, the papers thoroughly review and analyze this rapidly evolving area of computational electromagnetics. Covering topics ranging from the new finite-element based formulation for representing time-harmonic vector fields in 3-D inhomogeneous media using two coupled sca

  11. Bilateral Internal Thoracic Artery Configuration for Coronary Artery Bypass Surgery

    Science.gov (United States)

    Boodhwani, Munir; Hanet, Claude; de Kerchove, Laurent; Navarra, Emiliano; Astarci, Parla; Noirhomme, Philippe; El Khoury, Gebrine

    2016-01-01

    Background— Bilateral internal thoracic arteries (BITA) have demonstrated superior patency and improved survival in patients undergoing coronary artery bypass grafting. However, the optimal configuration for BITA utilization and its effect on long-term outcome remains uncertain. Methods and Results— We randomly assigned 304 patients undergoing coronary artery bypass grafting using BITA to either in situ or Y grafting configurations. The primary end point was 3-year angiographic patency. Secondary end points included major adverse cardiac and cerebrovascular events (ie, death from any cause, stroke, myocardial infarction, or repeat revascularization) at 7 years. More coronary targets were able to be revascularized using internal thoracic arteries in patients randomized to Y grafting versus in situ group (3.2±0.8 versus 2.4±0.5 arteries/patient; PURL: http://www.clinicaltrials.gov. Unique identifier: NCT01666366. PMID:27406988

  12. Genetics Home Reference: pulmonary arterial hypertension

    Science.gov (United States)

    ... Home Health Conditions pulmonary arterial hypertension pulmonary arterial hypertension Enable Javascript to view the expand/collapse boxes. ... All Open All Close All Description Pulmonary arterial hypertension is a progressive disorder characterized by abnormally high ...

  13. Revascularisation versus medical treatment in patients with stable coronary artery disease: network meta-analysis

    OpenAIRE

    Windecker, Stephan; Stortecky, Stefan; Stefanini, Giulio G; da Costa, Bruno R.; Rutjes, Anne Wilhelmina; Di Nisio, Marcello; Silletta, Maria G; Maione, Ausilia; Alfonso, Fernando; Clemmensen, Peter M; Collet, Jean-Philippe; Cremer, Jochen; Falk, Volkmar; Filippatos, Gerasimos; Hamm, Christian

    2014-01-01

    OBJECTIVE To investigate whether revascularisation improves prognosis compared with medical treatment among patients with stable coronary artery disease. DESIGN Bayesian network meta-analyses to combine direct within trial comparisons between treatments with indirect evidence from other trials while maintaining randomisation. ELIGIBILITY CRITERIA FOR SELECTING STUDIES A strategy of initial medical treatment compared with revascularisation by coronary artery bypass grafting...

  14. Effects of simulated microgravity on arterial nitric oxide synthase and nitrate and nitrite content

    Science.gov (United States)

    Ma, Jin; Kahwaji, Chadi I.; Ni, Zhenmin; Vaziri, Nosratola D.; Purdy, Ralph E.

    2003-01-01

    The aim of the present work was to investigate the alterations in nitric oxide synthase (NOS) expression and nitrate and nitrite (NOx) content of different arteries from simulated microgravity rats. Male Wistar rats were randomly assigned to either a control group or simulated microgravity group. For simulating microgravity, animals were subjected to hindlimb unweighting (HU) for 20 days. Different arterial tissues were removed for determination of NOS expression and NOx. Western blotting was used to measure endothelial NOS (eNOS) and inducible NOS (iNOS) protein content. Total concentrations of NOx, stable metabolites of nitric oxide, were determined by the chemiluminescence method. Compared with controls, isolated vessels from simulated microgravity rats showed a significant increase in both eNOS and iNOS expression in carotid arteries and thoracic aorta and a significant decrease in eNOS and iNOS expression of mesenteric arteries. The eNOS and iNOS content of cerebral arteries, as well as that of femoral arteries, showed no differences between the two groups. Concerning NOx, vessels from HU rats showed an increase in cerebral arteries, a decrease in mesenteric arteries, and no change in carotid artery, femoral artery and thoracic aorta. These data indicated that there were differential alterations in NOS expression and NOx of different arteries after hindlimb unweighting. We suggest that these changes might represent both localized adaptations to differential body fluid redistribution and other factors independent of hemodynamic shifts during simulated microgravity.

  15. Artery Soft-Tissue Modelling for Stent Implant Training System

    Directory of Open Access Journals (Sweden)

    Giovanni Aloisio

    2004-08-01

    Full Text Available Virtual reality technology can be utilised to provide new systematic training methods for surgical procedures. Our aim is to build a simulator that allows medical students to practice the coronary stent implant procedure and avoids exposing patients to risks. The designed simulation system consists of a virtual environment and a haptic interface, in order to provide both the visualization of the coronary arteries and the tactile and force feedback generated during the interactions of the surgical instruments in the virtual environment. Since the arteries are soft tissues, their shape may change during an operation; for this reason physical modelling of the organs is necessary to render their behaviour under the influence of surgeon's instruments. The idea is to define a model that computes the displacement of the tissue versus time; from the displacement it is possible to calculate the response of the tissue to the surgical tool external stimuli. Information about tools displacements and tissue responses are also used to graphically model the artery wall and virtual surgical instrument deformations generated as a consequence of their coming into contact. In order to obtain a realistic simulation, the Finite Element Method has been used to model the soft tissues of the artery, using linear elasticity to reduce computational time and speed up interaction rates.

  16. Finite element coiled cochlea model

    Science.gov (United States)

    Isailovic, Velibor; Nikolic, Milica; Milosevic, Zarko; Saveljic, Igor; Nikolic, Dalibor; Radovic, Milos; Filipović, Nenad

    2015-12-01

    Cochlea is important part of the hearing system, and thanks to special structure converts external sound waves into neural impulses which go to the brain. Shape of the cochlea is like snail, so geometry of the cochlea model is complex. The simplified cochlea coiled model was developed using finite element method inside SIFEM FP7 project. Software application is created on the way that user can prescribe set of the parameters for spiral cochlea, as well as material properties and boundary conditions to the model. Several mathematical models were tested. The acoustic wave equation for describing fluid in the cochlea chambers - scala vestibuli and scala timpani, and Newtonian dynamics for describing vibrations of the basilar membrane are used. The mechanical behavior of the coiled cochlea was analyzed and the third chamber, scala media, was not modeled because it does not have a significant impact on the mechanical vibrations of the basilar membrane. The obtained results are in good agreement with experimental measurements. Future work is needed for more realistic geometry model. Coiled model of the cochlea was created and results are compared with initial simplified coiled model of the cochlea.

  17. Clinical efficacy of intra-arterial thrombolsis for basilar artery occlusion

    International Nuclear Information System (INIS)

    Objective: To evaluate the efficacy and influence of intra-arterial thrombolysis for basilar artery occlusion. Methods: Thirty-three consecutive cases of basilar artery occlusion treated by intra-arterial thrombolysis were retrospectively reviewed. They were 25 males and 8 females aged from 28 to 71 years old (average: 56±11 years). The recovery was graded by Glasgow outcome scale, which 1 to 3 point is unfavorable and 4 to 5 is favorable. The short-term follow-up was performed referring to the medical record at the time of discharge and the long-term follow-up was performed by telephone. The differences between the favorable and unfavorable, including sex, age, time to thrombolysis, dizziness, nystagmus, coma, bilateral babinski syndrome, occlusive part, revascularization, angioplasty and its type, were compared by Fisher exact test where P<0.05 was significant. Results: The short-term follow-up was evaluated during the admission (2 to 63 days, 21±16 days). Eighteen eases were favorable and 15 cases were unfavorable and 3 cases died. Twenty one cases showed revascularization and 19 cases showed bilateral positive Babinski sign. The positive Babinski sign, revascularization and coma had significant difference between the favorable and unfavorable (P<0.05). The sex, age, time to thrombolysis between the favorable and unfavorable showed no statistical difference. The long-term follow-up were performed after 1 year and 9 cases missed. 15 of them were favorable and 6 were unfavorable (4 cases died). Conclusion: The intra-arterial thrombolysis could improved the prognosis of basilar artery occlusion. (authors)

  18. Pulmonary arterial hypertension : an update

    NARCIS (Netherlands)

    Hoendermis, E. S.

    2011-01-01

    Pulmonary arterial hypertension (PAH), defined as group 1 of the World Heart Organisation (WHO) classification of pulmonary hypertension, is an uncommon disorder of the pulmonary vascular system. It is characterised by an increased pulmonary artery pressure, increased pulmonary vascular resistance a

  19. Plasma levels of the arterial wall protein fibulin-1 are associated with carotid-femoral pulse wave velocity

    DEFF Research Database (Denmark)

    Laugesen, Esben; Høyem, Pernille; Christiansen, Jens Sandahl;

    2013-01-01

    The arterial system in diabetic patients is characterized by generalized non-atherosclerotic alterations in the vascular extracellular matrix causing increased arterial stiffness compared with subjects without diabetes. The underlying pathophysiology remains elusive. The elastin-associated extrac......The arterial system in diabetic patients is characterized by generalized non-atherosclerotic alterations in the vascular extracellular matrix causing increased arterial stiffness compared with subjects without diabetes. The underlying pathophysiology remains elusive. The elastin...... stiffness. Whether plasma fibulin-1 is associated with arterial stiffness at earlier phases of type 2 diabetes has not been determined....

  20. MR manifestations of vertebral artery injuries in cervical spine trauma

    International Nuclear Information System (INIS)

    To assess the diagnostic efficacy of magnetic resonance (MR) imaging in the detection of a vertebral artery injury occurring from major cervical spine trauma. Conventional MR findings of 63 patients and 63 control subjects were compared to detect a possible change in the vertebral arteries resulted from trauma. Plain films, CT and clinical records were also reviewed to correlate the degree of cervical spine injury with vascular change. Nine cases of absent flow signals in vessel lumen were observed in eight patients and one was observed in the control group. Patients more frequently demonstrated other abnormalities such as intraluminal linear signals (n=3) or focal luminal narrowing (n=9) but there was no statistical significance. There was a close relationship between degree of cord damage and occlusion of the vertebral artery. Conventional MR imaging is useful in the detection of vertebral artery occlusion resulting from cervical spine trauma

  1. Non-Linear Finite Element Modeling of THUNDER Piezoelectric Actuators

    Science.gov (United States)

    Taleghani, Barmac K.; Campbell, Joel F.

    1999-01-01

    A NASTRAN non-linear finite element model has been developed for predicting the dome heights of THUNDER (THin Layer UNimorph Ferroelectric DrivER) piezoelectric actuators. To analytically validate the finite element model, a comparison was made with a non-linear plate solution using Von Karmen's approximation. A 500 volt input was used to examine the actuator deformation. The NASTRAN finite element model was also compared with experimental results. Four groups of specimens were fabricated and tested. Four different input voltages, which included 120, 160, 200, and 240 Vp-p with a 0 volts offset, were used for this comparison.

  2. Nonlinear finite element modeling of THUNDER piezoelectric actuators

    Science.gov (United States)

    Taleghani, Barmac K.; Campbell, Joel F.

    1999-06-01

    A NASTRAN non-linear finite element model has been developed for predicting the dome heights of THUNDER (Thin Layer Unimorph Ferroelectric Driver) piezoelectric actuators. To analytically validate the finite element model, a comparison was made with a non-linear plate solution using Von Karmen's approximation. A 500 volt input was used to examine the actuator deformation. The NASTRAN finite element model was also compared with experimental results. Four groups of specimens were fabricated and tested. Four different input voltages, which included 120, 160, 200, and 240 Vp-p with a 0 volts offset, were used for this comparison.

  3. Some Notes on Finite Sets

    OpenAIRE

    Preston, Chris

    2015-01-01

    These notes aim to give a gentle account to one approach to the theory of finite sets without making use of the natural numbers. They were written to be used as the basis for a student seminar. There are no real prerequisites except for a certain familiarity with the kind of mathematics seen in the first couple of years of a university mathematics course. The definition of being finite employed in these notes is usually called Kuratowski-finiteness and it is essentially that employed by White...

  4. Photon propagators at finite temperature

    International Nuclear Information System (INIS)

    We have used the real time formalism to compute the one-loop finite temperature corrections to the photon self energies in spinor and scalar QED. We show that, for a real photon, only the transverse components develop the temperature-dependent masses, while, for an external static electromagnetic field applied to the finite temperature system, only the static electric field is screened by thermal fluctuations. After showing how to compute systematically the imaginary parts of the finite temperature Green functions, we have attempted to give a microscopic interpretation of the imaginary parts of the self energies. (author)

  5. Finite element computational fluid mechanics

    Science.gov (United States)

    Baker, A. J.

    1983-01-01

    Finite element analysis as applied to the broad spectrum of computational fluid mechanics is analyzed. The finite element solution methodology is derived, developed, and applied directly to the differential equation systems governing classes of problems in fluid mechanics. The heat conduction equation is used to reveal the essence and elegance of finite element theory, including higher order accuracy and convergence. The algorithm is extended to the pervasive nonlinearity of the Navier-Stokes equations. A specific fluid mechanics problem class is analyzed with an even mix of theory and applications, including turbulence closure and the solution of turbulent flows.

  6. Carotid endarterectomy for atherosclerotic carotid artery stenosis

    International Nuclear Information System (INIS)

    Several randomized controlled trials (RCTs) have demonstrated carotid endarterectomy (CEA) to be more beneficial for the prevention of recurrent or first-ever ischemic stroke than treatment with antiplatelet agents in patients with moderate-severe stenosis of the cervical internal carotid artery. CEA is the standard treatment for such lesions; however, other RCTs have demonstrated carotid artery stenting (CAS) with a protective device to be comparable to CEA in patients with or without radiological or medical high-risks for CEA, although the selection criteria among these treatments have not yet been established in clinical practice. This review compares the results of RCTs valuating the superiority of CEA over medical treatment or CAS, preoperative examination, procedures of CEA, perioperative management and complications, long-term results, and indications for CEA based on the currently available evidence-based publications. A preoperative evaluation of the patients' medical condition, including atherosclerosis, is therefore important to minimize the perioperative complications of CEA, because myocardial infarction during the perioperative period is frequently observed in patients undergoing CEA. A through radiological examination such as plaque imaging is essential for selecting appropriate treatment strategies involving revascularization or medical treatment for atherosclerotic carotid artery stenosis. In addition, the surgical indications, particularly for asymptomatic lesions, should be carefully considered in light of the recent improvements in medical treatments including antihypertensive agents and statins. (author)

  7. Liver cirrhosis and arterial hypertension

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Møller, Søren

    2006-01-01

    blood pressure. This review considers the alterations in systemic hemodynamics in patients with cirrhosis in relation to essential hypertension and arterial hypertension of the renal origin. Subjects with arterial hypertension (essential, secondary) may become normotensive during the development of...... cirrhosis, and arterial hypertension is rarely manifested in patients with cirrhosis, even in cases with renovascular disease and high circulating renin activity. There is much dispute as to the understanding of homoeostatic regulation in cirrhotic patients with manifest arterial hypertension. This most......Characteristic findings in patients with cirrhosis are vasodilatation with low overall systemic vascular resistance, high arterial compliance, increased cardiac output, secondary activation of counter-regulatory systems (renin-angiotensin-aldosterone system, sympathetic nervous system, release of...

  8. Relationship of cerebral arterial stenosis to cognitive and memory disorders

    Institute of Scientific and Technical Information of China (English)

    Jifeng Li; Zhou Wang; Shenggang Sun; Gaomei Cai; Kejin Gu; Yaoqun Li

    2006-01-01

    BACKGROUND: Cerebral arterial stenosis can cause cerebral hypoperfusion, and than result in the decline of cognitive function, whereas the cognitive dysfunction induced by different cerebral arterial stenosis have different manifestations and types.OBJECTIVE: To observe the differences of cognitive and memory dysfunctions in patients with cerebral arterial stenosis of different types.DESIGN: A comparative observation.SETTING: Affiliated Hospital of Jining Medical College.PARTICIPANTS: Forty-two outpatients or inpatients with cerebral arterial stenosis were selected from the Department of Neurology, Affiliated Hospital of Jining Medical College from February 2005 to January 2006,including 25 males and 17 females. There were 18 cases of internal carotid arterial stenosis, 14 cases of vertebrobasilar arterial stenosis and 10 cases of whole cerebral arterial stenosis. The diagnostic standards for cerebral arterial stenosis were identified according to North American Symptomatic Carotid Endarterectomy Trial (NAS CET). Meanwhile, 18 healthy physical examinees were enrolled as the control group, including 10males and 8 females, aged 58-80 years old. All the enrolled subjects were informed and agreed with the detection and evaluation.METHODS: ① The memory function was evaluated using revised Wechsler memory scale for adults, including long-term memory (experience, orientation and counting), short-term memory (visual recognition, picture memory, visual regeneration, association and thigmesthesia) and sensory memory (forward and backward recitation of numbers). The scale scores were turned to memory quotients. The higher the scores, the better the memory function. ② The cognitive function was evaluated using revised Wechsler adult intelligence scale:It consisted of eleven subtests, including six language scales (information, digit span, vocabulary, arithmetics,apprehension, similarity) and five operation scales (picture completion, picture arrangement, block design

  9. Sequential bilateral retinal artery occlusion

    Directory of Open Access Journals (Sweden)

    Padrón-Pérez N

    2014-04-01

    Full Text Available Noel Padrón-Pérez,1 Janny Rosario Aronés,2 Silvia Muñoz,1 Luis Arias-Barquet,1 Jorge Arruga1,31Department of Ophthalmology, Hospital Universitari de Bellvitge, 2Hospital de l'Esperança – Parc de Salut Mar, 3Institut Català de Retina, Barcelona, SpainAbstract: An 86 year old woman experienced a sequential bilateral loss of vision over a period of less than 24 hours. Clinical findings and complementary studies suggested a bilateral atherogenic embolic event. Initially, she presented a superior branch retinal artery occlusion in her right eye followed by a central retinal artery occlusion with cilioretinal artery sparing in her left eye. Some conservative maneuvers performed did not improve visual acuity in the left eye. Supra-aortic Doppler ultrasonography revealed mild right internal carotid artery stenosis and moderate left internal carotid artery stenosis with a small, smooth, and homogeneous plaque. The transthoracic echocardiography showed a severe calcification of the mitral valve with a mild-moderate rim of stenosis. Central retinal artery occlusion and branch retinal artery occlusion are characterized by painless monocular loss of vision. Clinical approach and management attempt to treat the acute event, find the source of the vascular occlusion, and prevent further vascular events from occurring. Giant cell arteritis is a potentially treatable cause of central retinal artery occlusion and should be excluded in every single patient over 50 years old.Keywords: loss of vision, branch retinal artery occlusion, central retinal artery occlusion, Hollenhorst plaque

  10. Order 1 autoregressive process of finite length

    CERN Document Server

    Vamos, Calin; Craciun, Maria

    2007-01-01

    The stochastic processes of finite length defined by recurrence relations request additional relations specifying the first terms of the process analogously to the initial conditions for the differential equations. As a general rule, in time series theory one analyzes only stochastic processes of infinite length which need no such initial conditions and their properties are less difficult to be determined. In this paper we compare the properties of the order 1 autoregressive processes of finite and infinite length and we prove that the time series length has an important influence mainly if the serial correlation is significant. These different properties can manifest themselves as transient effects produced when a time series is numerically generated. We show that for an order 1 autoregressive process the transient behavior can be avoided if the first term is a Gaussian random variable with standard deviation equal to that of the theoretical infinite process and not to that of the white noise innovation.

  11. Finite Element Analysis of Honeycomb Impact Attenuator

    Science.gov (United States)

    Yang, Seung-Yong; Choi, Seung-Kyu; Kim, Nohyu

    To participate in Student Formula Society of Automotive Engineers (SAE) competitions, it is necessary to build an impact attenuator that would give an average deceleration not to exceed 20g when it runs into a rigid wall. Students can use numerical simulations or experimental test data to show that their car satisfies this safety requirement. A student group to study formula cars at the Korea University of Technology and Education has designed a vehicle to take part in a SAE competition, and a honeycomb structure was adopted as the impact attenuator. In this paper, finite element calculations were carried out to investigate the dynamic behavior of the honeycomb attenuator. Deceleration and deformation behaviors were studied. Effect of the yield strength was checked by comparing the numerical results. ABAQUS/Explicit finite element code was used.

  12. Finite element modelling of solidification phenomena

    Indian Academy of Sciences (India)

    K N Seetharamu; R Paragasam; Ghulam A Quadir; Z A Zainal; B Sathya Prasad; T Sundararajan

    2001-02-01

    The process of solidification process is complex in nature and the simulation of such process is required in industry before it is actually undertaken. Finite element method is used to simulate the heat transfer process accompanying the solidification process. The metal and the mould along with the air gap formation is accounted in the heat transfer simulation. Distortion of the casting is caused due to non-uniform shrinkage associated with the process. Residual stresses are induced in the final castings. Simulation of the shrinkage and the thermal stresses are also carried out using finite element methods. The material behaviour is considered as visco-plastic. The simulations are compared with available experimental data and the comparison is found to be good. Special considerations regarding the simulation of solidification process are also brought out.

  13. EXERCISE-INDUCED ARTERIAL ADAPTATIONS IN ELITE JUDO ATHLETES

    Directory of Open Access Journals (Sweden)

    Panagiotis Karagounis

    2009-09-01

    Full Text Available The purpose of this study was to examine exercise-induced arterial adaptations in elite Judo male and female athletes. 27 male Judo athletes (age 24.06 ± 2 years, 11 female Judoka (age 24.27 ± 1 years, 27 sedentary healthy men (age 24.01 ± 2 years and 11 women (age 24.21 ± 1 years participated in the current study. The examined vessels included brachial, radial, ulnar, popliteal, anterior and posterior tibial arteries. The experimental parameters were recorded with the use of Duplex ultrasound at rest. Diastolic diameter and blood mean flow velocity of the examined arteries in Judo athletes were found to be both significantly increased (p < 0.05 compared to the findings of the control groups. In male Judo athletes the brachial (p < 0.001, radial (p < 0.001, and anterior tibial artery (p < 0.001 presented the highest difference on the diastolic diameter, compared with the control male group. In female Judo athletes, ulnar (p < 0.001, radial (p < 0.001, and brachial (p < 0.001 arteries illustrated the highest diastolic diameter. The highest blood mean flow velocity was recorded in ulnar (p < 0.001 and popliteal arteries (p < 0.001 of the Judo athletes groups. Recording differences between the two genders, male participants presented larger arteries than females. Conclusively, Judo has been found to be a highly demanding physical sport, involving upper and lower limbs leading to significant arterial adaptations. Obtaining vascular parameters provide a useful tool to the medical team, not only in the direction of enhancement of the efficacy of physical training, but in unknown so far parameters that may influence athletic performance of both male and female elite Judokas

  14. Patent arterial duct

    Directory of Open Access Journals (Sweden)

    Martin Robin P

    2009-07-01

    Full Text Available Abstract Patent arterial duct (PAD is a congenital heart abnormality defined as persistent patency in term infants older than three months. Isolated PAD is found in around 1 in 2000 full term infants. A higher prevalence is found in preterm infants, especially those with low birth weight. The female to male ratio is 2:1. Most patients are asymptomatic when the duct is small. With a moderate-to-large duct, a characteristic continuous heart murmur (loudest in the left upper chest or infraclavicular area is typical. The precordium may be hyperactive and peripheral pulses are bounding with a wide pulse pressure. Tachycardia, exertional dyspnoea, laboured breathing, fatigue or poor growth are common. Large shunts may lead to failure to thrive, recurrent infection of the upper respiratory tract and congestive heart failure. In the majority of cases of PAD there is no identifiable cause. Persistence of the duct is associated with chromosomal aberrations, asphyxia at birth, birth at high altitude and congenital rubella. Occasional cases are associated with specific genetic defects (trisomy 21 and 18, and the Rubinstein-Taybi and CHARGE syndromes. Familial occurrence of PAD is uncommon and the usual mechanism of inheritance is considered to be polygenic with a recurrence risk of 3%. Rare families with isolated PAD have been described in which the mode of inheritance appears to be dominant or recessive. Familial incidence of PAD has also been linked to Char syndrome, familial thoracic aortic aneurysm/dissection associated with patent arterial duct, and familial patent arterial duct and bicuspid aortic valve associated with hand abnormalities. Diagnosis is based on clinical examination and confirmed with transthoracic echocardiography. Assessment of ductal blood flow can be made using colour flow mapping and pulsed wave Doppler. Antenatal diagnosis is not possible, as PAD is a normal structure during antenatal life. Conditions with signs and symptoms of

  15. Automated carotid artery intima layer regional segmentation

    International Nuclear Information System (INIS)

    Evaluation of the carotid artery wall is essential for the assessment of a patient's cardiovascular risk or for the diagnosis of cardiovascular pathologies. This paper presents a new, completely user-independent algorithm called carotid artery intima layer regional segmentation (CAILRS, a class of AtheroEdge(TM) systems), which automatically segments the intima layer of the far wall of the carotid ultrasound artery based on mean shift classification applied to the far wall. Further, the system extracts the lumen-intima and media-adventitia borders in the far wall of the carotid artery. Our new system is characterized and validated by comparing CAILRS borders with the manual tracings carried out by experts. The new technique is also benchmarked with a semi-automatic technique based on a first-order absolute moment edge operator (FOAM) and compared to our previous edge-based automated methods such as CALEX (Molinari et al 2010 J. Ultrasound Med. 29 399-418, 2010 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57 1112-24), CULEX (Delsanto et al 2007 IEEE Trans. Instrum. Meas. 56 1265-74, Molinari et al 2010 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57 1112-24), CALSFOAM (Molinari et al Int. Angiol. (at press)), and CAUDLES-EF (Molinari et al J. Digit. Imaging (at press)). Our multi-institutional database consisted of 300 longitudinal B-mode carotid images. In comparison to semi-automated FOAM, CAILRS showed the IMT bias of -0.035 ± 0.186 mm while FOAM showed -0.016 ± 0.258 mm. Our IMT was slightly underestimated with respect to the ground truth IMT, but showed uniform behavior over the entire database. CAILRS outperformed all the four previous automated methods. The system's figure of merit was 95.6%, which was lower than that of the semi-automated method (98%), but higher than that of the other automated techniques.

  16. Automated carotid artery intima layer regional segmentation

    Science.gov (United States)

    Meiburger, Kristen M.; Molinari, Filippo; Rajendra Acharya, U.; Saba, Luca; Rodrigues, Paulo; Liboni, William; Nicolaides, Andrew; Suri, Jasjit S.

    2011-07-01

    Evaluation of the carotid artery wall is essential for the assessment of a patient's cardiovascular risk or for the diagnosis of cardiovascular pathologies. This paper presents a new, completely user-independent algorithm called carotid artery intima layer regional segmentation (CAILRS, a class of AtheroEdge™ systems), which automatically segments the intima layer of the far wall of the carotid ultrasound artery based on mean shift classification applied to the far wall. Further, the system extracts the lumen-intima and media-adventitia borders in the far wall of the carotid artery. Our new system is characterized and validated by comparing CAILRS borders with the manual tracings carried out by experts. The new technique is also benchmarked with a semi-automatic technique based on a first-order absolute moment edge operator (FOAM) and compared to our previous edge-based automated methods such as CALEX (Molinari et al 2010 J. Ultrasound Med. 29 399-418, 2010 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57 1112-24), CULEX (Delsanto et al 2007 IEEE Trans. Instrum. Meas. 56 1265-74, Molinari et al 2010 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57 1112-24), CALSFOAM (Molinari et al Int. Angiol. (at press)), and CAUDLES-EF (Molinari et al J. Digit. Imaging (at press)). Our multi-institutional database consisted of 300 longitudinal B-mode carotid images. In comparison to semi-automated FOAM, CAILRS showed the IMT bias of -0.035 ± 0.186 mm while FOAM showed -0.016 ± 0.258 mm. Our IMT was slightly underestimated with respect to the ground truth IMT, but showed uniform behavior over the entire database. CAILRS outperformed all the four previous automated methods. The system's figure of merit was 95.6%, which was lower than that of the semi-automated method (98%), but higher than that of the other automated techniques.

  17. Automated carotid artery intima layer regional segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Meiburger, Kristen M; Molinari, Filippo [Biolab, Department of Electronics, Politecnico di Torino, Torino (Italy); Acharya, U Rajendra [Department of ECE, Ngee Ann Polytechnic (Singapore); Saba, Luca [Department of Radiology, A.O.U. di Cagliari, Cagliari (Italy); Rodrigues, Paulo [Department of Computer Science, Centro Universitario da FEI, Sao Paulo (Brazil); Liboni, William [Neurology Division, Gradenigo Hospital, Torino (Italy); Nicolaides, Andrew [Vascular Screening and Diagnostic Centre, London (United Kingdom); Suri, Jasjit S, E-mail: filippo.molinari@polito.it [Fellow AIMBE, CTO, Global Biomedical Technologies Inc., CA (United States)

    2011-07-07

    Evaluation of the carotid artery wall is essential for the assessment of a patient's cardiovascular risk or for the diagnosis of cardiovascular pathologies. This paper presents a new, completely user-independent algorithm called carotid artery intima layer regional segmentation (CAILRS, a class of AtheroEdge(TM) systems), which automatically segments the intima layer of the far wall of the carotid ultrasound artery based on mean shift classification applied to the far wall. Further, the system extracts the lumen-intima and media-adventitia borders in the far wall of the carotid artery. Our new system is characterized and validated by comparing CAILRS borders with the manual tracings carried out by experts. The new technique is also benchmarked with a semi-automatic technique based on a first-order absolute moment edge operator (FOAM) and compared to our previous edge-based automated methods such as CALEX (Molinari et al 2010 J. Ultrasound Med. 29 399-418, 2010 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57 1112-24), CULEX (Delsanto et al 2007 IEEE Trans. Instrum. Meas. 56 1265-74, Molinari et al 2010 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57 1112-24), CALSFOAM (Molinari et al Int. Angiol. (at press)), and CAUDLES-EF (Molinari et al J. Digit. Imaging (at press)). Our multi-institutional database consisted of 300 longitudinal B-mode carotid images. In comparison to semi-automated FOAM, CAILRS showed the IMT bias of -0.035 {+-} 0.186 mm while FOAM showed -0.016 {+-} 0.258 mm. Our IMT was slightly underestimated with respect to the ground truth IMT, but showed uniform behavior over the entire database. CAILRS outperformed all the four previous automated methods. The system's figure of merit was 95.6%, which was lower than that of the semi-automated method (98%), but higher than that of the other automated techniques.

  18. Surgical techniques of arterialized orthotopic liver transplantation in rats

    Institute of Scientific and Technical Information of China (English)

    MA Yi; WANG Guo-dong; GUO Zhi-yong; GUO Zhi-gang; HE Xiao-shun; CHEN Gui-hua

    2007-01-01

    Background Recently, much attention has been paid to hepatic artery reconstruction in rat liver transplantation, which can prevent bile duct ischemia and preserve better liver structure. In this study, three methods of graft arterialization,including sleeve, cuff, and stent anastomosis, were conducted and the results were compared.Methods Orthotopic liver transplantation (OLT) with rearterialization was conducted in 90 rats, which were divided into sleeve, cuff, and stent groups (n=30 in each). Ninety-six rats received OLTs with standardized two-cuff technique without rearterialization as a control. The sleeve technique included an end-to-end anastomosis between the donor common hepatic artery and recipient proper hepatic artery, or between the donor celiac artery and recipient common hepatic artery.Cuff technique involved an anastomosis between the donor common hepatic artery and recipient common hepatic artery.In the stent technique, the recipient hepatic artery and donor hepatic artery were connected using an intraluminal polyethylene stent. The arterial anastomosis time and arterial patency rate in each group were recorded. The liver graft survival and bile duct complication rates were measured.Results The total surgical time of OLT with rearterialization was (118.3±12.9) minutes in the sleeve group, (106.2±11.6)minutes in the cuff, (93.8±10.2) minutes in the stent, and (88.2±9.6) minutes in the control. The corresponding anhepatic phase was (19.6±2.8), (19.2±2.2), (18.6±1.8), and (20.0±2.5) minutes respectively in the sleeve, cuff, stent, and control groups. One-week survival rate was 86.5% in the control, and 86.7% in the groups with rearterialization. No significant difference was detected in the survival rate between them (P>0.05). The incidence of biliary complications in non-rearterialized group (17.7%) was significantly higher than that in the rearterialized group (6.7%, P<0.05). No significant difference was found in the incidence of biliary

  19. Isovector collective response function of nuclear matter at finite temperature

    International Nuclear Information System (INIS)

    We study isovector collective excitations in nuclear matter by employing the linearized Landau–Vlasov equation with and without a non-Markovian binary collision term at finite temperature. We calculate the giant dipole resonance (GDR) strength function for finite nuclei using the Steinwedel–Jensen model and also by Thomas–Fermi approximation, and we compare them for 120Sn and 208Pb with experimental results. (author)

  20. Finite Field Arithmetic Architecture Based on Cellular Array

    Directory of Open Access Journals (Sweden)

    Kee-Won Kim

    2015-05-01

    Full Text Available Recently, various finite field arithmetic structures are introduced for VLSI circuit implementation on cryptosystems and error correcting codes. In this study, we present an efficient finite field arithmetic architecture based on cellular semi-systolic array for Montgomery multiplication by choosing a proper Montgomery factor which is highly suitable for the design on parallel structures. Therefore, our architecture has reduced a time complexity by 50% compared to typical architecture.

  1. Purity Relative to Classes of Finitely Presented Modules

    OpenAIRE

    Mehdi, Akeel Ramadan

    2013-01-01

    Any set of finitely presented left modules defines a relative purity for left modules and also apurity for right modules. Purities defined by various classes are compared and investigated,especially in the contexts of modules over semiperfect rings and over tame hereditary, andmore general, finite-dimensional algebras. Connections between the indecomposable relativelypure-injective modules and closure in the full support topology (a refinement of theZiegler spectrum) are described.Duality bet...

  2. Average dynamics of a finite set of coupled phase oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Dima, Germán C., E-mail: gdima@df.uba.ar; Mindlin, Gabriel B. [Laboratorio de Sistemas Dinámicos, IFIBA y Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 1, Ciudad Universitaria, Buenos Aires (Argentina)

    2014-06-15

    We study the solutions of a dynamical system describing the average activity of an infinitely large set of driven coupled excitable units. We compared their topological organization with that reconstructed from the numerical integration of finite sets. In this way, we present a strategy to establish the pertinence of approximating the dynamics of finite sets of coupled nonlinear units by the dynamics of its infinitely large surrogate.

  3. Quantum entanglement of localized excited states at finite temperature

    OpenAIRE

    Caputa, Pawel; Simón, Joan; Štikonas, Andrius(School of Mathematics and Maxwell Institute for Mathematical Sciences, University of Edinburgh, King’s Buildings, Edinburgh, EH9 3FD, U.K.); Takayanagi, Tadashi

    2015-01-01

    In this work we study the time evolutions of (Renyi) entanglement entropy of locally excited states in two dimensional conformal field theories (CFTs) at finite temperature.We consider excited states created by acting with local operators on thermal states and give both field theoretic and holographic calculations. In free field CFTs, we find that the growth of Renyi entanglement entropy at finite temperature is reduced compared to the zero temperature result by a small quantity proportional ...

  4. Finite volume hydromechanical simulation in porous media

    OpenAIRE

    Nordbotten, Jan Martin

    2014-01-01

    Cell-centered finite volume methods are prevailing in numerical simulation of flow in porous media. However, due to the lack of cell-centered finite volume methods for mechanics, coupled flow and deformation is usually treated either by coupled finite-volume-finite element discretizations, or within a finite element setting. The former approach is unfavorable as it introduces two separate grid structures, while the latter approach loses the advantages of finite volume methods for the flow equ...

  5. Fourier Transforms of Finite Chirps

    Directory of Open Access Journals (Sweden)

    Fickus Matthew

    2006-01-01

    Full Text Available Chirps arise in many signal processing applications. While chirps have been extensively studied as functions over both the real line and the integers, less attention has been paid to the study of chirps over finite groups. We study the existence and properties of chirps over finite cyclic groups of integers. In particular, we introduce a new definition of a finite chirp which is slightly more general than those that have been previously used. We explicitly compute the discrete Fourier transforms of these chirps, yielding results that are number-theoretic in nature. As a consequence of these results, we determine the degree to which the elements of certain finite tight frames are well distributed.

  6. Supersymmetry at finite temperature revisited

    Energy Technology Data Exchange (ETDEWEB)

    Paranjape, M.B.; Taormina, A.; Wijewardhana, L.C.R.

    1983-05-02

    The authors have formulated sypersymmetry at finite temperature, generalizing the recent observations by Van Hove. They find that in a two-dimensional model broken supersymmetry is not restored at high temperature.

  7. Supersymmetry at Finite Temperature Revisited

    Science.gov (United States)

    Paranjape, M. B.; Taormina, A.; Wijewardhana, L. C. R.

    1983-05-01

    The authors have formulated supersymmetry at finite temperature, generalizing the recent observations by Van Hove. They find that in a two-dimensional model broken supersymmetry is not restored at high temperature.

  8. Combinatorial Properties of Finite Models

    CERN Document Server

    Hubicka, Jan

    2010-01-01

    We study countable embedding-universal and homomorphism-universal structures and unify results related to both of these notions. We show that many universal and ultrahomogeneous structures allow a concise description (called here a finite presentation). Extending classical work of Rado (for the random graph), we find a finite presentation for each of the following classes: homogeneous undirected graphs, homogeneous tournaments and homogeneous partially ordered sets. We also give a finite presentation of the rational Urysohn metric space and some homogeneous directed graphs. We survey well known structures that are finitely presented. We focus on structures endowed with natural partial orders and prove their universality. These partial orders include partial orders on sets of words, partial orders formed by geometric objects, grammars, polynomials and homomorphism orders for various combinatorial objects. We give a new combinatorial proof of the existence of embedding-universal objects for homomorphism-defined...

  9. A case of primitive persistent hypoglossal artery

    Energy Technology Data Exchange (ETDEWEB)

    Park, C. K.; Koh, B. H.; Kim, Y. S.; Kang, S. R. [Hangyang University College of Medicine, Seoul (Korea, Republic of)

    1979-06-15

    Three kinds of carotid-basilar anastomosis have been found, they were named as persistent primitive trigeminal artery, persistent primitive acoustic (or otic) artery and persistent primitive hypoglossal artery, among them, the persistent primitive hypoglossal artery is by far the least common type of the internal carotid-basilar anastomosis which have been demonstrate in human postembryonic stages. Persistent primitive by hypoglossal artery is usually found incidentally. This vascular anomaly, however,have been reported to be associated with multiple congenital anomalies, such as unilateral or bilateral vertebral artery hypoplasia, absence of the posterior communicating artery, hypoplasia of the proximal portion of the posterior cerebral artery, aneurysm of the circle of Willis, the origin of both pericallosal arteries from a single anterior cerebral artery, retarded mental development dating from infancy, carotid-cavernous fistula formation etc. A case of persistent primitive hypoglossal artery in an young Korean male was reported with brief review of the literature.

  10. Carotid arteries in central retinal vessel occlusion as assessed by Doppler ultrasound.

    OpenAIRE

    Peternel, P; Keber, D; Videcnik, V

    1989-01-01

    Doppler ultrasound was used to detect possible flow changes in the carotid arteries of patients with central retinal artery and vein occlusion. Twenty-three patients with central retinal artery occlusion (mean age 56, SD 11, years) were examined 4 to 48 months after the development of the occlusion and compared with age and sex matched control subjects with no history of any disease known to be associated with pathological changes in carotid vessels. Significant stenosis or occlusion of one o...

  11. A Review of Genetics, Arterial Stiffness, and Blood Pressure in African Americans

    OpenAIRE

    Hall, Jennifer L.; Duprez, Daniel A; Barac, Ana; Rich, Stephen S.

    2012-01-01

    The prevalence of hypertension in African Americans in the United States is amongst the highest in the world and increasing. The identification of genes and pathways regulating blood pressure in African Americans has been challenging. An early predictor of hypertension is arterial stiffness. The prevalence of arterial stiffness is significantly higher in African Americans compared to Caucasians. Approximately 20% of the variance in arterial stiffness is estimated to be heritable. Identifying ...

  12. Genes Involved in Systemic and Arterial Bed Dependent Atherosclerosis - Tampere Vascular Study

    OpenAIRE

    Mari Levula; Niku Oksala; Nina Airla; Rainer Zeitlin; Juha-Pekka Salenius; Otso Järvinen; Maarit Venermo; Teemu Partio; Jukka Saarinen; Taija Somppi; VeliPekka Suominen; Jyrki Virkkunen; Juha Hautalahti; Reijo Laaksonen; Mika Kähönen

    2012-01-01

    BACKGROUND: Atherosclerosis is a complex disease with hundreds of genes influencing its progression. In addition, the phenotype of the disease varies significantly depending on the arterial bed. METHODOLOGY/PRINCIPAL FINDINGS: We characterized the genes generally involved in human advanced atherosclerotic (AHA type V-VI) plaques in carotid and femoral arteries as well as aortas from 24 subjects of Tampere Vascular study and compared the results to non-atherosclerotic internal thoracic arterie...

  13. Assessment of normal and atherosclerotic arterial wall thickness with an intravascular ultrasound imaging catheter.

    OpenAIRE

    Mallery, JA; Tobis, JM; Griffith, J.; Gessert, J; McRae, M; Moussabeck, O; Bessen, M; Moriuchi, M; Henry, WL

    1990-01-01

    A prototype intravascular ultrasound imaging catheter with a 20 MHz transducer was used to obtain 59 cross-sectional images in 14 segments of human atherosclerotic arteries. Three distinct components of the arterial wall were visualized on the ultrasound images: a highly reflective intima, an echolucent media, and a moderately reflective adventitia. Images were obtained at 1 mm increments in vitro and were compared with histologic sections at the same levels. Measurements of the arterial laye...

  14. Decreased Vertebral Artery Hemodynamics in Patients with Loss of Cervical Lordosis

    OpenAIRE

    Bulut, Mehmet Deniz; Alpayci, Mahmut; Şenköy, Emre; Bora, Aydin; Yazmalar, Levent; Yavuz, Alpaslan; Gülşen, İsmail

    2016-01-01

    Background Because loss of cervical lordosis leads to disrupted biomechanics, the natural lordotic curvature is considered to be an ideal posture for the cervical spine. The vertebral arteries proceed in the transverse foramen of each cervical vertebra. Considering that the vertebral arteries travel in close anatomical relationship to the cervical spine, we speculated that the loss of cervical lordosis may affect vertebral artery hemodynamics. The aim of this study was to compare the vertebra...

  15. Measurement of Blood Pressure Using an Arterial Pulsimeter Equipped with a Hall Device

    OpenAIRE

    Jong-Gu Choi; Keun-Ho Kim; Woo-Beom Lee; Dong-Hyun Nam; Il-Ho Son; You-Sik Hong; Sang-Suk Lee

    2011-01-01

    To measure precise blood pressure (BP) and pulse rate without using a cuff, we have developed an arterial pulsimeter consisting of a small, portable apparatus incorporating a Hall device. Regression analysis of the pulse wave measured during testing of the arterial pulsimeter was conducted using two equations of the BP algorithm. The estimated values of BP obtained by the cuffless arterial pulsimeter over 5 s were compared with values obtained using electronic or liquid mercury BP meters. The...

  16. Effect of stenosed and occluded coronary arteries on immediate and late myocardial uptake of thallium-201.

    OpenAIRE

    Clitsakis, D; Layton, C A; Battersby, W; Johns, M; Stockley, A V

    1981-01-01

    Exercise and redistribution myocardial scintigraphy using thallium-201 was compared with the left ventricular angiogram and with the presence of stenosis or occlusion of coronary arteries on angiography. Irreversible scintigraphic defects representing areas of myocardial infarction were found in all patients with occlusion of the left anterior descending artery but nearly one-third of patients with stenosis of that artery also showed evidence of infarction. For the right coronary or circumfle...

  17. Spontaneous Coronary Artery Dissection.

    Science.gov (United States)

    Tweet, Marysia S; Gulati, Rajiv; Hayes, Sharonne N

    2016-07-01

    Spontaneous coronary artery dissection is an important etiology of nonatherosclerotic acute coronary syndrome, myocardial infarction, and sudden death. Innovations in the catheterization laboratory including optical coherence tomography and intravascular ultrasound have enhanced the ability to visualize intimal disruption and intramural hematoma associated with SCAD. Formerly considered "rare," these technological advances and heightened awareness suggest that SCAD is more prevalent than prior estimates. SCAD is associated with female sex, young age, extreme emotional stress, or extreme exertion, pregnancy, and fibromuscular dysplasia. The clinical characteristics and management strategies of SCAD patients are different than for atherosclerotic heart disease and deserve specific consideration. This review will highlight recent discoveries about SCAD as well as describe current efforts to elucidate remaining gaps in knowledge. PMID:27216840

  18. Coronary artery disease (CAD)

    International Nuclear Information System (INIS)

    The detection of myocardial ischemia is the most relevant indication of myocardial perfusion scintigraphy. P. Marie exposes the sensibility and specificity of the method, based on an analysis of literature. Myocardial perfusion scintigraphy gives prognostical informations: among them, should be highlighted the excellent prognosis of a normal perfusion scintigraphy even in patients with significant coronary stenosis and the poor prognosis of extensive perfusion defects at stress. P. Rigo details echocardiographic techniques and nuclear medicine techniques to assess patients with coronary artery disease. He analyses the pathophysiological principles and clinical indications of these techniques. Then, he exposes a quantification analysis software based on bull'eyes representation. M. Slama points out the complementarity of coronary angiography and myocardial perfusion scintigraphy. (authors)

  19. Peripheral artery atherectomy

    International Nuclear Information System (INIS)

    Twenty-one femoropopliteal percutaneous transluminal atherectomies were performed with the Simpson catheter. Evaluation included clinical examination, Doppler ultrasonography (ankle-arm index, before and immediately and 1,3 and 6 months after atherectomy), and angiography (6 months after or for clinical worsening). Twenty of 21 procedures achieved satisfactory vessel patency, with the addition of complementary angioplasty for residual stenosis over 30% (one of three cases). Early thrombosis occurred in only one of 21 cases (absence of platelet inhibitor pretherapy), and no distal embolization occurred. Six-month follow-up showed stable improvements in 11 of 12 patients and restenosis in only one (absence of platelet inhibitor pretherapy). Preliminary results indicate that atherectomy is the method of choice for restoring large lumens, with minimal arterial wall injury and fewer cases of restenosis than with angioplasty

  20. Anomalous Origin of Right Coronary Artery from Distal Left Circumflex Artery: A Very Rare Variant of Single Coronary Artery Anomaly

    OpenAIRE

    Arash Gholoobi

    2016-01-01

    Among coronary anomalies, Single Coronary Artery (SCA) is a rare anomaly in which one coronary artery stems from a single coronary ostium from the aortic sinuses, nourishing the entire heart. A very rare subtype of this anomaly is the anomalous origin of the Right Coronary Artery (RCA) from the distal Left Circumflex (LCx) artery.

  1. Lung effect on the hemodynamics in pulmonary artery

    Science.gov (United States)

    Tsai, S. F.; Sheu, Tony W. H.; Chang, T. M.

    2001-06-01

    The present study investigates blood flow in a pulmonary artery. The aim is to gain a better understanding of offset value in vascular circulation through a two-dimensional analysis of the Navier-Stokes equations. In this study, the hemodynamics in a blood vessel with truncated outlets at which constant pressure is specified is examined. To simplify the analysis, the vessel walls are regarded as being rigid. In quadratic elements, the streamline upwind Petrov-Galerkin finite element model is employed to simulate the incompressible Newtonian blood flow. The adopted finite element model introduces artificial damping terms solely in the streamline direction. With these terms added to the formulation, the discrete system is enhanced while solution accuracy is maintained without deterioration due to numerical diffusion errors. Copyright

  2. Cerebellar arteries originating from the internal carotid artery: angiographic evaluation and embryologic explanations

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Young; Han, Moon Hee; Yu, In Gyu; Chang, Ki Hyun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of); Kim, Eui Jong [Kyunghee Univ. College of Medicine, Seoul (Korea, Republic of); Kim, Dae Ho [Soonchunhyang Univ. College of Medicine, Asan(Korea, Republic of)

    1997-06-01

    To find and describe the cerebellar arteries arising from the internal carotid artery, explain them embryologically, and evaluate their clinical implication. To determine the point in the internal carotid artery from which the cereballar artery arose anomalously, consecutive angiographic studies performed in the last three years were reviewed. The distribution of such anomalous cerebellar arteries, the point in the internal carotid artery from which the anomalous vessels originated, and associated findings were analyzed. Five anomalous origins of cerebellar arteries arising arising directly from the internal carotid artery were found in five patients. Three anterior inferior cerebellar arteries (AICA) and one common trunk of an AICA and a posterior inferior cerebellar artery (PICA) were found to originate from the internal carotid artery at a point close to the origin of the primitive trigeminal artery. A PICA arose from an artery presenting a course similar to the proatlantal intersegmental artery. Intracranial aneurysms in two patients, Moyamoya disease in one, and facial arteriovenous malformation in one. In our series, AICAs supplied from the arteries considered to be persistent trigeminal artery variants were the most common type. A correlation between type of anomalous cerebellar artery and type of carotid-vertebrobasilar anastomosis may exist. Cerebellar arteries originating anomalously from the internal carotid artery seem to occur as a result of the persistence of carotid-vertebrobasilar anastomoses associated with incomplete fusion of the longitudinal neural arteries. An understanding of these anomalous cerebellar arteries may help prevent accidents during therapeutic embolization and surgical treatment, as well as misinterpretation.

  3. STUDY OF MEDIAL CIRCUMFLEX ARTERY

    Directory of Open Access Journals (Sweden)

    Pavan P Havaldar

    2014-06-01

    Full Text Available Background: The proper knowledge of the course and ramification of blood vessels of lower limbs is very important for surgeons and interventional radiologist. Medial circumflex femoral artery usually originates from posteromedial aspect of the profunda femoris, but often originates from femoral artery itself. It has an important role in supplying blood to femoral neck and head, fatty tissue in acetabular fossa and used in flaps reconstructive surgery. Methods: 50 adult lowerlimbs were procured from embalmed cadavers of J.J.M. Medical College and S.S.I.M.S & R.C, Davangere, Karnataka, India for the study. Dissection of femoral triangle was carried out according to Cunningham’s manual. Site and mode of origin of the branches of femoral artery were studied, configuration of the femoral origins of medial and lateral circumflex femoral artery and their prevalence were studied. Results: Out of 50 extremities, Medial circumflex femoral artery took origin from profunda femoris in 41 specimens and from femoral artery in 9 specimens. Conclusion: The knowledge of normal origin and variation of medial circumflex femoral artery is very valuable in preventing iatrogenic injury to these vessels during surgical procedures of femoral triangle.

  4. Access to the ophthalmic artery by retrograde approach through the posterior communicating artery for intra-arterial chemotherapy of retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Chi-Tuan; Blanc, Raphael; Pistocchi, Silvia; Bartolini, Bruno; Piotin, Michel [Fondation Rothschild Hospital, Department of Interventional Neuroradiology, Paris (France); Lumbroso-Le Rouic, Livia [Institut Curie, Department of Ocular Oncology, Paris (France)

    2012-08-15

    Intra-arterial infusion of chemotherapy into the ophthalmic artery for treatment of retinoblastoma has been realized after catheterization of the internal carotid and temporary balloon occlusion beyond the orifice of the ophthalmic artery, or more recently after superselective canulation of the ophthalmic artery by a microcatheter. The superselective catheterization of the ophthalmic artery could be cumbersome because of the implantation of the ostium on the carotid siphon or because of the tortuosity of the carotid siphon. We report our experience of using a retrograde approach through the posterior communicating artery that allows a more direct angle of access to the origin of the ophthalmic artery. (orig.)

  5. Access to the ophthalmic artery by retrograde approach through the posterior communicating artery for intra-arterial chemotherapy of retinoblastoma

    International Nuclear Information System (INIS)

    Intra-arterial infusion of chemotherapy into the ophthalmic artery for treatment of retinoblastoma has been realized after catheterization of the internal carotid and temporary balloon occlusion beyond the orifice of the ophthalmic artery, or more recently after superselective canulation of the ophthalmic artery by a microcatheter. The superselective catheterization of the ophthalmic artery could be cumbersome because of the implantation of the ostium on the carotid siphon or because of the tortuosity of the carotid siphon. We report our experience of using a retrograde approach through the posterior communicating artery that allows a more direct angle of access to the origin of the ophthalmic artery. (orig.)

  6. Peripheral arterial stenosis and coronary artery disease coincidence

    Directory of Open Access Journals (Sweden)

    Reza Ghasemi

    2014-12-01

    Full Text Available Atherosclerosis is a chronic slow-developing condition affecting medium-size and large blood vessels. It is the principal underlying pathology of coronary heart disease and stroke. In some countries, coronary artery disease (CAD is the cause of nearly half (48% of the deaths and, loss of productivity life. Peripheral arterial disease (PAD is defined as atherosclerosis in peripheral arteries instead of coronary arteries. CAD and PAD have same risk factors and underlying pathophysiological processes. Therefore, patient with CAD should be considered for PAD. Ankle brachial index (ABI, duplex sonography, and some other non-invasive techniques are recommended for PAD diagnosis in patients with the history of CAD. Pharmacotherapy, endovascular interventions, and surgical management could be chosen according to the patient’s situation. Cardiologists and general practitioners should consider PAD in a patient with CAD or DM as a strong correlated disease.      

  7. Local Intra-Arterial Fibrinolysis in Acute Basilar Artery Occlusion

    OpenAIRE

    Enomoto, Y.; Yoshimura, S.; Kitajima, H.; Tamakawa, N.; Iwama, T

    2007-01-01

    Acute basilar artery (BA) occlusion is typically associated with poor outcome; however newer diagnostic and treatment modalities have the potential to improve prognosis. In this study, six patients with acute BA occlusion were followed and the effectiveness of local intra-arterial fibrinolysis (LIF) and subsequent percutaneous transluminal angioplasty (PTA) with a balloon catheter were assessed. Of the six patients with BA occlusion observed in this study, two had extended brain stem infarcti...

  8. Non-Newtonian effects of blood on LDL transport inside the arterial lumen and across multi-layered arterial wall with and without stenosis

    Science.gov (United States)

    Deyranlou, Amin; Niazmand, Hamid; Sadeghi, Mahmood-Reza; Mesri, Yaser

    2016-06-01

    Blood non-Newtonian behavior on low-density lipoproteins (LDL) accumulation is analyzed numerically, while fluid-multilayered arteries are adopted for nonstenotic and 30%-60% symmetrical stenosed models. Present model considers non-Newtonian effects inside the lumen and within arterial layers simultaneously, which has not been examined in previous studies. Navier-Stokes equations are solved along with the mass transport convection-diffusion equations and Darcy’s model for species transport inside the luminal flow and across wall layers, respectively. Carreau model for the luminal flow and the modified Darcy equation for the power-law fluid within arterial layers are employed to model blood rheological characteristics, appropriately. Results indicate that in large arteries with relatively high Reynolds number Newtonian model estimates LDL concentration patterns well enough, however, this model seriously incompetent for regions with low WSS. Moreover, Newtonian model for plasma underestimates LDL concentration especially on luminal surface and across arterial wall. Therefore, applying non-Newtonian model seems essential for reaching to a more accurate estimation of LDL distribution in the artery. Finally, blood flow inside constricted arteries demonstrates that LDL concentration patterns along the stenoses inside the luminal flow and across arterial layers are strongly influenced as compared to the nonstenotic arteries. Additionally, among four stenosis severity grades, 40% stenosis is prone to more LDL accumulation along the post-stenotic regions.

  9. [Variability of the celiac artery and its branches in sheep].

    Science.gov (United States)

    Karmona, Kh; Kovachev, G

    1985-01-01

    Contrast matter was used with a total of 363 sheep fetuses, newborn lambs, and adult sheep to study the variability of the coeliac artery and its branches. It was found that the artery and some of its branches, such as arteria ruminalis sinistra, arteria reticularis, and arteria lienalis often showed variations, resp., deviations in their branching and distribution. Others, such as arteria ruminalis dextra and arteria hepatica showed no variations whatever. Both the coeliac artery and the anterior intestinal artery in the sheep were most often shown to branch from the aorta alone (in 71.07 per cent of the cases) as against the rarely observed common truncus coeliacomesentericus (in 28.93 per cent of the cases). The most commonly observed form of branching of arteria coeliaca seemed to be tripus coeliacus, while the branching with the formation of a short truncus hepatogastricus was comparatively a rare phenomenon. It was also established that the left ruminal artery was much more frequently the branch of truncus lienoruminalis than the branch of arteria gastrica sinistra. So far as the place in which arteria reticularis arose three variants were observed. Most frequently this artery was shown to be the branch of arteria gastrica sinistra. PMID:4013078

  10. Arterial Stiffening and Clinical Outcomes in Dialysis Patients.

    Science.gov (United States)

    Kato, Akihiko

    2015-09-01

    Cardiovascular disease (CVD) is an important cause of morbidity and mortality in dialysis patients. Brachial-ankle pulse wave velocity (baPWV) is more efficient to handily assess arteriosclerosis than aortic PWV. The cardio-ankle vascular index (CAVI) is also a novel blood pressure-independent arterial stiffness parameter. In dialysis patients, both baPWV and CAVI are increased compared to general subjects. Several studies have demonstrated that increased baPWV is associated with carotid atherosclerosis and diastolic left ventricular dysfunction in hemodialysis (HD) patients. In addition, higher baPWV is related to all-cause and cardiovascular (CV) mortality. CAVI is similarly associated with CVD. However, baPWV is superior to CAVI as a predictor of CV outcomes in HD patients. Besides these outcomes, a close relationship exists between sarcopenia, abdominal visceral obesity and arterial stiffening. Reduction of thigh muscle mass is inversely correlated with baPWV and CAVI in males. Abdominal fatness is also associated with increased arterial stiffness in females. These observations provide further evidence of higher risk of CV events in HD patients with sarcopenic obesity. In addition, arterial stiffness is associated with cerebral small vessel disease and decreased cognitive function in the elderly. However, it is unknown whether arterial stiffness may be useful as an early indicator of cognitive decline in dialysis patients. Because dialysis patients are at risk of developing dementia, more studies are needed to elucidate the causal link between arterial stiffness and cognitive impairment. PMID:26587457

  11. Peripheral artery disease in patients with coronary artery disease.

    Science.gov (United States)

    Atmer, B; Jogestrand, T; Laska, J; Lund, F

    1995-03-01

    The prevalence of peripheral vascular disease in patients with coronary artery disease has been investigated in many different ways and depends on the diagnostic methods and the definition of the atherosclerotic manifestations in the different vascular beds. In this study we used the non-invasive methods digital volume pulse plethysmography and ankle and toe blood pressure measurements to identify arterial abnormalities in the lower limbs in 58 patients (49 males and 9 females; age 37-72 years) examined with coronary angiography. The prevalence of peripheral artery disease was 22%, in agreement with the results of most previous investigations. There was a tendency towards increasing prevalence of peripheral artery disease with more advanced coronary artery disease: 14% of the patients with no or minimal coronary atheromotous lesions, 18% of the patients with moderate coronary atheromotous lesions and 32% of the patients with marked coronary atheromotous disease. For this reason a non-invasive investigation of the peripheral arterial circulation should be included early in the clinical consideration of patients with chest pain or similar symptoms suggesting coronary heart disease. Toe pressure measurement appears to be the most appropriate technique being rather simple in management and also in evaluation of results. PMID:7658111

  12. Improved finite element forms for the shallow-water wave equations

    OpenAIRE

    Williams, R T; Zienkiewicz, O.C.

    1981-01-01

    This paper presents new finite element formulations of the shallow-water wave equations which use different basis functions for the velocity and height fields. These arrangements are analysed with the Fourier transform technique which was developed by Schoenstadt,' and they are also compared with other finite difference and finite element schemes. The new schemes are integrated in time for two initial states and compared with analytic solutions and numerical solutions from other s...

  13. Diabetes is a predictor of coronary artery stenosis in patients hospitalized with heart failure.

    Science.gov (United States)

    Kosuga, Tsuneharu; Komukai, Kimiaki; Miyanaga, Satoru; Kubota, Takeyuki; Nakata, Kotaro; Suzuki, Kenichiro; Yamada, Takayuki; Yoshida, Jun; Kimura, Haruka; Yoshimura, Michihiro

    2016-05-01

    In patients with heart failure, coronary artery disease is the most common underlying heart disease, and is associated with increased mortality. However, estimating the presence or absence of coronary artery disease in patients with heart failure is sometimes difficult without coronary imaging. We reviewed 155 consecutive patients hospitalized with heart failure who underwent coronary angiography. The patients were divided into two groups: patients with (N = 59) and without (N = 96) coronary artery stenosis. The clinical characteristics and blood sampling data were compared between the two groups. The patients with coronary artery stenosis were older than those without. The prevalence of diabetes mellitus (DM), dyslipidemia and a history of revascularization was higher in the patients with coronary artery stenosis. Patients with coronary artery stenosis tended to have wall motion asynergy more frequently than those without. On the other hand, the prevalence of atrial fibrillation (AF) was lower in patients with coronary artery stenosis. The serum hemoglobin level and estimated glomerular filtration rate were lower in patients with coronary artery stenosis than in those without. In the multivariate analysis, DM (odds ratio 3.517, 95 % CI 1.601-7.727) was found to be the only the predictor of the presence of coronary artery stenosis in patients with heart failure. In conclusion, coronary imaging is strongly recommended for heart failure patients with DM to confirm the presence of coronary artery stenosis. PMID:25822806

  14. Aberrant ovarian artery arising from the common Iliac artery: Case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Kyung [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Yang, Seung Boo; Lee, Jae Myeong [Dept. of Radiology, Soonchunhyang University Gumi Hospital, Soonchunhyang University College of Medicine, Gumi (Korea, Republic of); Goo, Dong Erk; Kim, Yong Jae; Chang, Yun Woo [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul (Korea, Republic of)

    2013-01-15

    A 46-year-old Vietnamese woman received embolization therapy in order to control postpartum hemorrhage. Angiography revealed an aberrant ovarian artery arising from the right common iliac artery. Superselective catheterization and subsequent embolization of the aberrant ovarian artery and bilateral uterine arteries were performed. Precise knowledge of the anatomic variations of the ovarian artery is important for successful embolization.

  15. Pulmonary arterial hypertension.

    Science.gov (United States)

    Montani, David; Günther, Sven; Dorfmüller, Peter; Perros, Frédéric; Girerd, Barbara; Garcia, Gilles; Jaïs, Xavier; Savale, Laurent; Artaud-Macari, Elise; Price, Laura C; Humbert, Marc; Simonneau, Gérald; Sitbon, Olivier

    2013-01-01

    Pulmonary arterial hypertension (PAH) is a chronic and progressive disease leading to right heart failure and ultimately death if untreated. The first classification of PH was proposed in 1973. In 2008, the fourth World Symposium on PH held in Dana Point (California, USA) revised previous classifications. Currently, PH is devided into five subgroups. Group 1 includes patients suffering from idiopathic or familial PAH with or without germline mutations. Patients with a diagnosis of PAH should systematically been screened regarding to underlying mutations of BMPR2 gene (bone morphogenetic protein receptor type 2) or more rarely of ACVRL1 (activine receptor-like kinase type 1), ENG (endogline) or Smad8 genes. Pulmonary veno occusive disease and pulmonary capillary hemagiomatosis are individualized and designated as clinical group 1'. Group 2 'Pulmonary hypertension due to left heart diseases' is divided into three sub-groups: systolic dysfonction, diastolic dysfonction and valvular dysfonction. Group 3 'Pulmonary hypertension due to respiratory diseases' includes a heterogenous subgroup of respiratory diseases like PH due to pulmonary fibrosis, COPD, lung emphysema or interstitial lung disease for exemple. Group 4 includes chronic thromboembolic pulmonary hypertension without any distinction of proximal or distal forms. Group 5 regroup PH patients with unclear multifactorial mechanisms. Invasive hemodynamic assessment with right heart catheterization is requested to confirm the definite diagnosis of PH showing a resting mean pulmonary artery pressure (mPAP) of ≥ 25 mmHg and a normal pulmonary capillary wedge pressure (PCWP) of ≤ 15 mmHg. The assessment of PCWP may allow the distinction between pre-capillary and post-capillary PH (PCWP > 15 mmHg). Echocardiography is an important tool in the management of patients with underlying suspicion of PH. The European Society of Cardiology and the European Respiratory Society (ESC-ERS) guidelines specify its role

  16. Arterial hypertension as risk factor for spontaneous cervical artery dissection. A case–control study

    OpenAIRE

    Pezzini, A; Caso, V; Zanferrari, C; Del Zotto, E; Paciaroni, M; Bertolino, C; Grassi, M.(INFN Sezione di Roma, Roma, Italy); Agnelli, G.; Padovani, A

    2006-01-01

    Because of the presumed non‐atherosclerotic pathogenesis, the potential link between spontaneous cervical artery dissection (sCAD) and common risk factors for atherosclerosis has never been investigated systematically. Therefore, this prospective, multicentre, case–control study compared the frequency of tobacco use, hypertension, diabetes mellitus, and hypercholesterolaemia among a group of consecutive patients with sCAD (n  =  153), a group of patients with ischaemic stroke, not related to ...

  17. Revascularisation of atherosclerotic mesenteric arteries

    DEFF Research Database (Denmark)

    Christensen, Max Greve; Lorentzen, Jørgen Ewald; Schroeder, T V

    1994-01-01

    25 patients, chronic ischaemia in 53 and prophylactic reconstruction in connection with aortic surgery in 12 patients. The superior mesenteric artery (SMA) was revascularised in 87 patients and the coeliac axis or common hepatic artery in six. Thus, only three patients had both territories......OBJECTIVES: Visceral artery surgery is well known to vascular surgeons, but most have limited personal experience. We report our experience with 90 patients treated for atherosclerotic lesions of the visceral arteries during a 25-year period 1968-1993. DESIGN: Retrospective study. SETTING...... revascularised. Thromboendarterectomy was performed in 15 patients, transposition of the SMA directly into the infrarenal aorta in 30 and bypass in 48 patients. CHIEF OUTCOME MEASURES: Cumulative symptom-free and survival rates. MAIN RESULTS: The overall perioperative (30 days) mortality rate was 13%, mainly...

  18. A ruptured dissecting aneurysm of the vertebral artery: comparison of angiographic and histological findings

    International Nuclear Information System (INIS)

    We present autopsy findings in a patient with a dissecting aneurysm of the vertebral artery causing subarachnoid haemorrhage. We sectioned the artery longitudinally and compared it with the angiogram, which showed the ''pearl-and-string''. Histological examination showed a pseudoaneurysm covered by adventitia alone, forming the ''pearl''. Internal elastic lamina and media were destroyed, and haematoma extended in the subadventitial space of the wall of the pseudoaneurysm. Media thickened by haematoma caused the ''string'', narrowing the parent artery. Alcian blue staining showed that stratified internal elastic lamina in the aneurysm and the parent artery, had undergone marked mucoid degeneration, which may have been responsible for the dissection. (orig.)

  19. On the Finite Volume Reformulation of the Mixed Finite Elements Method on Triangles

    OpenAIRE

    Chavent, Guy; Younès, Anis; Mosé, Robert; Ackerer, Philippe

    1999-01-01

    We analyse the finite volume reformulation of the triangular mixed finite element approximation for the porous flow equation, as proposed in [10] [9]. We show that the finite volumes are obtained by aggregation of finite elements (usually one, sometimes two or more), that the matrix of the finite volume equations is regular, but generally not symmetrical, and that the finite volume formulation is algebraically equivalent to the mixed approximation. The finite volume matrix becomes symmetrical...

  20. Comparison of high-resolution contrast-enhanced 3D MRA with digital subtraction angiography in the evaluation of hepatic arterial anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Matoba, M. E-mail: m-matoba@kanazawa-med.ac.jp; Tonami, H.; Kuginuki, M.; Yokota, H.; Takashima, S.; Yamamoto, I

    2003-06-01

    AIM: To evaluate the validity of high-resolution contrast-enhanced three-dimensional magnetic resonance angiography (MRA) in defining hepatic arterial anatomy and to compare this with digital subtraction angiography (DSA). MATERIALS AND METHODS: MRA and DSA were performed in 30 patients. MRA was performed with breath-hold, gadolinium-enhanced, three-dimensional, fast low-angle shot sequence with a 512 pixel matrix. MRA was compared with DSA in terms of image quality and depiction of hepatic arterial anatomy. The agreement in image quality between MRA and DSA was determined with the kappa statistic. RESULTS: With respect to image quality, there was excellent or good correlation between MRA and DSA for the common hepatic artery ({kappa}=0.85), proper hepatic artery ({kappa}=0.72), gastroduodenal artery ({kappa}=0.70), left hepatic artery ({kappa}=0.49), left gastric artery ({kappa}=0.50), splenic artery ({kappa}=0.84), and superior mesenteric artery ({kappa}=0.88). Poor correlation was found for the right hepatic artery ({kappa}=0.18) and right gastric artery ({kappa}=0.38). With regard to hepatic arterial anatomy, MRA correlated correctly with DSA in 28 of the 29 cases, i.e. 97% of patients. CONCLUSION: MRA is a useful technique for the evaluation of the hepatic artery, and for the vast majority of patients, MRA can replace intra-arterial DSA.

  1. Computerized axial tomography of the chest for visualization of ''absent'' pulmonary arteries

    International Nuclear Information System (INIS)

    To expand the search for central pulmonary arteries in six patients with absence of cardiac-pulmonary continuity, computerized axial tomography (CAT) of the chest was performed. The CAT scans were compared with previous arteriograms and pulmonary vein wedge angiograms. Three patients with type IV truncus arteriosus were studied, and none had a central, right or left pulmonary artery on CAT scan. However, two patients with tetralogy of Fallot with pulmonary atresia and a patent ductus arteriosus to the right lung demonstrated the presence of a left pulmonary artery. In addition, one child with truncus arteriosus with ''absent'' left pulmonary artery demonstrated a left pulmonary artery on the CAT scan. The CAT scan may therefore enhance our ability to search for disconnected pulmonary arteries in children with complex cyanotic congenital heart disease

  2. Finite Mordell-Tornheim multiple zeta values

    OpenAIRE

    Kamano, Ken

    2016-01-01

    We investigate a finite analogue of the Mordell-Tornheim multiple zeta values (the finite Mordell-Tornheim multiple zeta values). These values can be expressed by a linear combination of finite multiple zeta values, and its rules are described by the shuffle product. As a~corollary, we give a certain relation among finite multiple zeta values.

  3. A Finite Speed Curzon-Ahlborn Engine

    Science.gov (United States)

    Agrawal, D. C.

    2009-01-01

    Curzon and Ahlborn achieved finite power output by introducing the concept of finite rate of heat transfer in a Carnot engine. The finite power can also be achieved through a finite speed of the piston on the four branches of the Carnot cycle. The present paper combines these two approaches to study the behaviour of output power in terms of…

  4. Irradiation injury to large arteries

    International Nuclear Information System (INIS)

    Four cases of irradiation injury to large arteries following radiotherapy treatment are presented and the literature is reviewed. Three patterns of injury have emerged: 1) intimal damage resulting in mural thrombosis presenting within 5 years of irradiation, 2) fibrotic occlusion presenting within 10 years of injury, and 3) a predisposition to the development of atheroma together with periarterial fibrosis associated with a latent interval of 20 or more years. The treatment of choice is a bypass procedure of the arterial lesion. (author)

  5. Biomarkers of Peripheral Arterial Disease

    OpenAIRE

    Cooke, John P.; Wilson, Andrew M.

    2010-01-01

    Atherosclerotic arterial occlusive disease affecting the lower extremities is also known as peripheral arterial disease (PAD). This disorder affects 8 to 12 million individuals in the United States, and is also increasingly prevalent in Europe and Asia (1–4). Unfortunately, most patients are not diagnosed and are not optimally treated. A blood test for PAD, if sufficiently sensitive and specific, would be expected to improve recognition and treatment of these individuals. Even a biomarker pan...

  6. Pulmonary arterial hypertension: an update

    OpenAIRE

    Hoendermis, E.S.

    2011-01-01

    Pulmonary arterial hypertension (PAH), defined as group 1 of the World Heart Organisation (WHO) classification of pulmonary hypertension, is an uncommon disorder of the pulmonary vascular system. It is characterised by an increased pulmonary artery pressure, increased pulmonary vascular resistance and specific histological changes. It is a progressive disease finally resulting in right heart failure and premature death. Typical symptoms are dyspnoea at exercise, chest pain and syncope; furthe...

  7. Arterial Pressure Monitoring in Mice

    OpenAIRE

    Zhao, Xin; Ho, David; Gao, Shumin; Hong, Chull; Vatner, Dorothy E.; Vatner, Stephen F.

    2011-01-01

    The use of mice for the evaluation and study of cardiovascular pathophysiology is growing rapidly, primarily due to the relative ease for developing genetically engineered mouse models. Arterial pressure monitoring is central to the evaluation of the phenotypic changes associated with cardiovascular pathology and interventions in these transgenic and knockout models. There are four major techniques for measuring arterial pressure in the mouse: tail cuff system, implanted fluid filled catheter...

  8. Off-pump sequential bilateral internal mammary artery grafting combined with selective arterialization of the coronary venous system

    Institute of Scientific and Technical Information of China (English)

    YU Yang; YAN Xiao-lei; WEI Hua; YANG Jun-feng; GU Cheng-xiong

    2011-01-01

    Background Off-pump coronary artery bypass surgery (OPCAB) has been widely applied in recent years as a less invasive method of myocardial revascularization. This study evaluated the sequential bilateral internal mammary artery grafting combined with selective arterialization of the coronary venous system during OPCAB.Methods From April 2004 to August 2010, patients with diffuse right coronary lesions were studied retrospectively and divided into two groups. Group 1 included seventeen patients who underwent this surgery while group 2 included twenty-one patients without right coronary artery surgical therapy. All patients presented with symptoms of angina. Blood flow of bridged vessels was measured. The perioperative ventricular parameters including left ventricular ejection fraction and end diastolic diameter were compared. During follow-up, myocardial nuclide imaging and coronary angiography were carried out.Results Off-pump coronary artery bypass was performed with an average of 3.6 grafts per patient. Hospital mortality was zero. At the time of follow-up, the patients in group 1 recovered better than in group 2 (P<0.05). In both groups, the mean New York Heart Association (NYHA) class and ejection fraction increased significantly (P<0.001) and the mean left ventricular end-diastolic diameter decreased significantly (P <0.05). Myocardial blood supply of inferior wall in group 1 was obviously improved by myocardial nuclide imaging. Coronary angiography for eight patients in group 1 verified that there was blood flow to myocardium in the arterialized vein.Conclusions Sequential bilateral internal mammary artery grafting combined with selective arterialization of the coronary venous system can be performed during OPCAB. A postoperative improvement in the cardiac functions and the quality of life was documented, increasing our expectation for extensive application.

  9. Early Results of Coronary Endarterectomy Combined with Coronary Artery Bypass Grafting in Patients with Diffused Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Li-Qun Chi

    2015-01-01

    Full Text Available Background: It is still a challenge for the cardiac surgeons to achieve adequate revascularization for diffused coronary artery disease (CAD. Coronary endarterectomy (CE offers an alternative choice of coronary artery reconstruction and revascularization. In this study, short-term result of CE combined with coronary artery bypass graft (CABG was discussed in the treatment for the diffused CAD. Methods: From January 2012 to April 2014, 221 cases of CABG were performed by the same surgeon in our unit. Among these cases, 38 cases of CE + CABG were performed, which was about 17.2% (38/221 of the cohort. All these patients were divided into two groups: CE + CABG group (Group A and CABG alone group (Group B. All clinical data were compared between the two groups, and postoperative complications and in-hospital mortality were analyzed. The categorical and continuous variables were analyzed by Chi-square test and Student′s t-test respectively. Results: Diabetes mellitus, hypertension, hyperlipidemia, and peripheral vascular disease were more common in group A. In this cohort, a total of 50 vessels were endarterectomized. Among them, CE was performed on left anterior descending artery in 11 cases, on right coronary artery in 29 cases, on diagonal artery in 3 cases, on intermediate artery in 2 cases, on obtuse marginal artery in 5 cases. There was no hospital mortality in both groups. The intro-aortic balloon pump was required in 3 cases in Group A (3/38, which was more often than that in Group B (3/183. At the time of follow-up, coronary computed tomography angiogram showed all the grafts with CE were patent (50/50. There is no cardio-related mortality in both groups. All these patients were free from coronary re-intervention. Conclusions: Coronary endarterectomy + CABG can offer satisfactory result for patients with diffused CAD in a short-term after the operation.

  10. Abnormal pulmonary artery stiffness in pulmonary arterial hypertension: in vivo study with intravascular ultrasound.

    Directory of Open Access Journals (Sweden)

    Edmund M T Lau

    Full Text Available BACKGROUND: There is increasing recognition that pulmonary artery stiffness is an important determinant of right ventricular (RV afterload in pulmonary arterial hypertension (PAH. We used intravascular ultrasound (IVUS to evaluate the mechanical properties of the elastic pulmonary arteries (PA in subjects with PAH, and assessed the effects of PAH-specific therapy on indices of arterial stiffness. METHOD: Using IVUS and simultaneous right heart catheterisation, 20 pulmonary segments in 8 PAH subjects and 12 pulmonary segments in 8 controls were studied to determine their compliance, distensibility, elastic modulus and stiffness index β. PAH subjects underwent repeat IVUS examinations after 6-months of bosentan therapy. RESULTS: AT BASELINE, PAH SUBJECTS DEMONSTRATED GREATER STIFFNESS IN ALL MEASURED INDICES COMPARED TO CONTROLS: compliance (1.50±0.11×10(-2 mm(2/mmHg vs 4.49±0.43×10(-2 mm(2/mmHg, p<0.0001, distensibility (0.32±0.03%/mmHg vs 1.18±0.13%/mmHg, p<0.0001, elastic modulus (720±64 mmHg vs 198±19 mmHg, p<0.0001, and stiffness index β (15.0±1.4 vs 11.0±0.7, p = 0.046. Strong inverse exponential associations existed between mean pulmonary artery pressure and compliance (r(2 = 0.82, p<0.0001, and also between mean PAP and distensibility (r(2 = 0.79, p = 0.002. Bosentan therapy, for 6-months, was not associated with any significant changes in all indices of PA stiffness. CONCLUSION: Increased stiffness occurs in the proximal elastic PA in patients with PAH and contributes to the pathogenesis RV failure. Bosentan therapy may not be effective at improving PA stiffness.

  11. Non-invasive assessment of arterial stiffness using oscillometric blood pressure measurement

    Directory of Open Access Journals (Sweden)

    Komine Hidehiko

    2012-02-01

    Full Text Available Abstract Background Arterial stiffness is a major contributor to cardiovascular diseases. Because current methods of measuring arterial stiffness are technically demanding, the purpose of this study was to develop a simple method of evaluating arterial stiffness using oscillometric blood pressure measurement. Methods Blood pressure was conventionally measured in the left upper arm of 173 individuals using an inflatable cuff. Using the time series of occlusive cuff pressure and the amplitudes of pulse oscillations, we calculated local slopes of the curve between the decreasing cuff pressure and corresponding arterial volume. Whole pressure-volume curve was derived from numerical integration of the local slopes. The curve was fitted using an equation and we identified a numerical coefficient of the equation as an index of arterial stiffness (Arterial Pressure-volume Index, API. We also measured brachial-ankle (baPWV PWV and carotid-femoral (cfPWV PWV using a vascular testing device and compared the values with API. Furthermore, we assessed carotid arterial compliance using ultrasound images to compare with API. Results The slope of the calculated pressure-volume curve was steeper for compliant (low baPWV or cfPWV than stiff (high baPWV or cfPWV arteries. API was related to baPWV (r = -0.53, P r = -0.49, P r = 0.32, P Conclusions These results suggest that our method can simply and simultaneously evaluate arterial stiffness and blood pressure based on oscillometric measurements of blood pressure.

  12. Liver cirrhosis and arterial hypertension

    Institute of Scientific and Technical Information of China (English)

    Jens H Henriksen; Soren Moller

    2006-01-01

    Characteristic findings in patients with cirrhosis are vasodilatation with low overall systemic vascular resistance, high arterial compliance, increased cardiac output, secondary activation of counter-regulatory systems (renin-angiotensin-aldosterone system,sympathetic nervous system, release of vasopressin),and resistance to vasopressors. The vasodilatory state is mediated through adrenomedullin, calcitonin generelated peptide, nitric oxide, and other vasodilators,and is most pronounced in the splanchnic area.This constitutes an effective (although relative)counterbalance to increased arterial blood pressure.This review considers the alterations in systemic hemodynamics in patients with cirrhosis in relation to essential hypertension and arterial hypertension of the renal origin. Subjects with arterial hypertension (essential, secondary) may become normotensive during the development of cirrhosis, and arterial hypertension is rarely manifested in patients with cirrhosis, even in cases with renovascular disease and high circulating renin activity. There is much dispute as to the understanding of homoeostatic regulation in cirrhotic patients with manifest arterial hypertension. This most likely includes the combination of vasodilatation and vasoconstriction in parallel.

  13. Finite element solutions of free surface flows

    Science.gov (United States)

    Zarda, P. R.; Marcus, M. S.

    1977-01-01

    A procedure is presented for using NASTRAN to determine the flow field about arbitrarily shaped bodies in the presence of a free surface. The fundamental unknown of the problem is the velocity potential which must satisfy Laplace's equation in the fluid region. Boundary conditions on the free surface may involve second order derivatives in space and time. In cases involving infinite domains either a tractable radiation condition is applied at a truncated boundary or a series expansion is used and matched to the local finite elements. Solutions are presented for harmonic, transient, and steady state problems and compared to either exact solutions or other numerical solutions.

  14. Finite element methods in probabilistic mechanics

    Science.gov (United States)

    Liu, Wing Kam; Mani, A.; Belytschko, Ted

    1987-01-01

    Probabilistic methods, synthesizing the power of finite element methods with second-order perturbation techniques, are formulated for linear and nonlinear problems. Random material, geometric properties and loads can be incorporated in these methods, in terms of their fundamental statistics. By construction, these methods are applicable when the scale of randomness is not too large and when the probabilistic density functions have decaying tails. By incorporating certain computational techniques, these methods are shown to be capable of handling large systems with many sources of uncertainties. Applications showing the effects of combined random fields and cyclic loading/stress reversal are studied and compared with Monte Carlo simulation results.

  15. Arterial spin labeling in patients with chic cerebral artery steno-occlusive disease - Correlation with 15O-PET

    International Nuclear Information System (INIS)

    Background: Heterogeneity of arterial transit time due to cerebral artery steno-occlusive lesions hampers accurate regional cerebral blood flow measurement by arterial spin labeling (ASL). Purpose: To assess the feasibility of regional cerebral blood flow measurement by ASL with multiple-delay time sampling in patients with steno-occlusive diseases by comparing with positron emission tomography (PET), and to determine whether regional arterial transit time measured by this ASL technique is correlated with regional mean transit time, a PET index of perfusion pressure. Material and Methods: Sixteen patients with steno-occlusive diseases received both ASL and 15O-PET. The mean regional cerebral blood flow measured by ASL and PET, regional arterial transit time by ASL, and regional mean transit time by PET were obtained by a region-of-interest analysis. Correlation between regional cerebral blood flow by ASL and that by PET, and correlation between regional arterial transit time by ASL and regional mean transit time by PET were tested using Pearson's correlation coefficient for both absolute and relative values. A multivariate regression analysis was performed to test whether regional arterial transit time by ASL was a significant contributor in modeling regional mean transit time by PET after controlling the effect of regional cerebral blood flow by ASL. Results: A significant positive correlation was found between regional cerebral blood flow by ASL and that by PET for both absolute (r = 0.520, P < 0.0001) and relative (r = 0.691, P < 0.0001) values. A significant positive correlation was found between regional arterial transit time by ASL and regional mean transit time by PET both for absolute (r = 0.369, P = 0.0002) and relative (r = 0.443, P < 0.0001) values. The regression analysis revealed that regional arterial transit time by ASL was a significant contributor in modeling regional mean transit time by PET after controlling regional cerebral blood flow by ASL (P

  16. Differential analysis of clinical features in atherosclerotic renal artery stenosis and benign nephrosclerosis

    Institute of Scientific and Technical Information of China (English)

    郭云珊

    2006-01-01

    Objective To analyze and compare the clinical characteristics of atherosclerotic renal artery stenosis (ARAS) and benign nephrosclerosis (BN) in order to distinguish the ARAS from BN. Methods A retrospective study was performed on 82 hypertensive patients with renal injury. Patients were divided into BN and ARAS group according to renal artery doppler scanning. The

  17. MRI of the carotid artery at 7 Tesla: Quantitative comparison with 3 Tesla

    NARCIS (Netherlands)

    Koning, Wouter; De Rotte, Alexandra A J; Bluemink, Johanna J.; Van Der Velden, Tijl A.; Luijten, Peter R.; Klomp, DWJ; Zwanenburg, Jaco J M

    2015-01-01

    Purpose: To evaluate the 7 Tesla (T) MRI of the carotid arteries, as quantitatively compared with 3T. Materials and Methods: The 7T MRI of the carotid arteries was performed in six healthy subjects and in two patients with carotid stenosis. The healthy group was scanned at 3T and at 7T, using curren

  18. DETERMINATION OF AMMONIA IN EAR-LOBE CAPILLARY BLOOD IS AN ALTERNATIVE TO ARTERIAL BLOOD AMMONIA

    NARCIS (Netherlands)

    HUIZENGA, [No Value; GIPS, CH; CONN, HO; JANSEN, PLM

    1995-01-01

    Blood ammonia determination is a laboratory test to diagnose hepatic encephalopathy. Arterial blood is superior to peripheral venous blood ammonia because of ammonia metabolism in muscle. We have compared capillary with arterial whole blood ammonia as capillary sampling is an attractive alternative.

  19. In-depth characterization of CGRP receptors in human intracranial arteries

    DEFF Research Database (Denmark)

    Jansen-Olesen, Inger; Jørgensen, Linda; Engel, Ulla; Edvinsson, Lars

    meningeal arteries. Removal of the endothelium neither changed the maximum relaxant response nor the pIC(50) values for alpha- and beta-CGRP as compared to the responses in arteries with an intact endothelium. Human alpha-CGRP-(8-37) caused a shift of h alpha- and h beta-CGRP-induced relaxations in cerebral...

  20. First clinical experience with Celt ACD(®) : a femoral arterial puncture closure device.

    LENUS (Irish Health Repository)

    Jan, Aftab

    2013-08-01

    This prospective nonrandomized study compared the safety and efficacy of a novel arterial closure device (ACD) in common femoral artery procedures to that of the FDA submitted historical manual pressure control group, who underwent either a diagnostic angiogram (DA) or a percutaneous coronary intervention (PCI) procedure.

  1. Human urotensin II in internal mammary and radial arteries of patients undergoing coronary surgery

    DEFF Research Database (Denmark)

    Chen, Zhi-Wu; Yang, Qin; Huang, Yu; Fan, Li; Li, Xian-Wu; He, Guo-Wei

    AIMS: Internal mammary (IMA) and radial artery (RA) have different incidence of vasospasm and long-term patency rates in arterial grafting. We compared the vasoreactivity of human urotensin II (hU-II) and its receptor with mechanism investigations in IMA and RA. METHODS: IMA and RA taken from pat...

  2. The C-finite Ansatz

    CERN Document Server

    Zeilberger, Doron

    2011-01-01

    While it is trivial to multiply two C-finite sequences (just like integers), it is not quite so trivial to "factorize" them, or to decide whether they are "prime". The former is plain linear algebra, while the latter is heavy-duty non-linear algebra, getting hairy systems of algebraic equations that can be solved, in principle, using Gr\\"obner bases and the Buchberger algorithm, but, alas, sooner or later it becomes too hard even for the fastest and largest computers. The main technical novely of this article is a fast "algorithm" (it cheats and uses floating-point arithmetic, please don't tell anyone!) for deciding whether a given C-finite sequence can be written as a product of C-finite sequences of lower order. This article accompanies the Maple package Cfinite available from http://www.math.rutgers.edu/~zeilberg/tokhniot/Cfinite .

  3. Finite element methods for engineers

    CERN Document Server

    Fenner, Roger T

    2013-01-01

    This book is intended as a textbook providing a deliberately simple introduction to finite element methods in a way that should be readily understandable to engineers, both students and practising professionals. Only the very simplest elements are considered, mainly two dimensional three-noded “constant strain triangles”, with simple linear variation of the relevant variables. Chapters of the book deal with structural problems (beams), classification of a broad range of engineering into harmonic and biharmonic types, finite element analysis of harmonic problems, and finite element analysis of biharmonic problems (plane stress and plane strain). Full Fortran programs are listed and explained in detail, and a range of practical problems solved in the text. Despite being somewhat unfashionable for general programming purposes, the Fortran language remains very widely used in engineering. The programs listed, which were originally developed for use on mainframe computers, have been thoroughly updated for use ...

  4. Different radiation impedance models for finite porous materials

    DEFF Research Database (Denmark)

    Nolan, Melanie; Jeong, Cheol-Ho; Brunskog, Jonas;

    2015-01-01

    The Sabine absorption coefficients of finite absorbers are measured in a reverberation chamber according to the international standard ISO 354. They vary with the specimen size essentially due to diffraction at the specimen edges, which can be seen as the radiation impedance differing from the...... infinite case. Thus, in order to predict the Sabine absorption coefficients of finite porous samples, one can incorporate models of the radiation impedance. In this study, different radiation impedance models are compared with two experimental examples. Thomasson’s model is compared to Rhazi’s method when...... coupled to the transfer matrix method (TMM). These methods are found to yield comparable results when predicting the Sabine absorption coefficients of finite porous materials. Discrepancies with measurement results can essentially be explained by the unbalance between grazing and non-grazing sound field...

  5. Coronary arterial Disease associated with arteriosclerosis in lower extremity: Angiographic analysis

    International Nuclear Information System (INIS)

    We performed both peripheral and coronary angiographies in 52 patients with an arteriosclerosis in lower extremities. The severity of arteriosclerotic narrowing of the coronary and peripheral arteries were compared on angiographies. An angiographic vascular score(AVS, 0-5) reflecting the number and the degree of stenosis in 12 lower extremity arteries and three major coronary arteries was assigned to each angiogram and the sun of scores in the lower extremity arteries was compared with the incidence of significant coronary artery disease (more than grade 3) and coronary score. Relation of incidence and severity of vascular stenosis and risk factors (diabetes metallitus, hypertension, smoking, and hypercholesterolemia) was also analyzed. Thirty-four of 52 patients (65%) had an angiographically significant coronary artery disease. Thirteen of these 34 patients (38%) had no clinical symptom and sign of the ischemic heart disease. There was no statistically significant difference in the incidence and severity of coronary artery disease between high (more than 30) and low AVS group in lower extremity (p>0.14). All patients had at least one risk factor and 49 of 52 patients (94%) had multiple risk factors. Coronary angiography was normal in there patients with only one risk factors, and angiographically significant coronary artery disease existed in nine of 16 cases (56.3%) with two risk factors. 13 of 17 case (76.5%) with three risk factors, and 12 of 16 cases (75.0%) with all four risk factors. There were no significant correlations between individual risk factors and incidence, severity of arteriosclerosis in coronary and lower extremity arteries. In conclusion, angiographic evaluation of the coronary artery disease in patients with lower extremity arteriosclerosis is necessary because of the high chance of coronary artery disease and difficulty in the prediction of coronary artery disease with a severity of the peripheral arteriosclerosis, presence of various risk

  6. Solid finite elements through three decades

    OpenAIRE

    Venkatesh, DN; Shrinivasa, U

    1994-01-01

    conventionally, solid finite elements have been looked upon as just generalizations of two-dimensional finite elements. In this article we trace their development starting from the days of their inception. Keeping in tune with our perceptions on developing finite elements, without taking recourse to any extra variational techniques, we discuss a few of the techniques which have been applied to solid finite elements. Finally we critically examine our own work on formulating solid finite elemen...

  7. Finite Element Method: An Overview

    Directory of Open Access Journals (Sweden)

    Vishal JAGOTA

    2013-02-01

    Full Text Available The finite element method (FEM is a numerical analysis technique for obtaining approximate solutions to a wide variety of engineering problems. A finite element model of a problem gives a piecewise approximation to the governing equations. The basic premise of the FEM is that a solution region can be analytically modeled or approximated by replacing it with an assemblage of discrete elements (discretization. Since these elements can be put together in a variety of ways, they can be used to represent exceedingly complex shapes.

  8. Finite elements of nonlinear continua

    CERN Document Server

    Oden, J T

    2000-01-01

    Geared toward undergraduate and graduate students, this text extends applications of the finite element method from linear problems in elastic structures to a broad class of practical, nonlinear problems in continuum mechanics. It treats both theory and applications from a general and unifying point of view.The text reviews the thermomechanical principles of continuous media and the properties of the finite element method, and then brings them together to produce discrete physical models of nonlinear continua. The mathematical properties of these models are analyzed, along with the numerical s

  9. Radiation-induced carotid artery disease

    International Nuclear Information System (INIS)

    Nine patients with atherosclerotic carotid artery disease associated with neck radiation were compared to 40 control patients. The data suggest that significant differences in age, incidence of coronary and peripheral vascular disease, elevated lipids and serum cholesterol, and the angiographic incidence of disseminated atherosclerosis justify the description of radiation-induced carotid disease as a clinical entity. Elevated serum cholesterol and hyperlipidemia may contribute to the development of radiation-induced vascular disease. Successful surgical reconstruction does not appear to be influenced by the prior radiotherapy, although periarterial fibrosis and increased difficulty in separating the plaques from the vascular media was encountered

  10. Graft patency in off-pump and conventional coronary artery bypass grafting for treatment of triple vessel coronary disease

    Institute of Scientific and Technical Information of China (English)

    胡盛寿; 王小启; 宋云虎; 吕锋

    2003-01-01

    Objective To compare graft patency in off-pump and conventional coronary artery bypass grafting by using the transit time flow meter in the treatment of triple vessel coronary artery disease. Methods Between June 2000 and April 2001, 60 patients with triple vessel coronary artery disease underwent coronary artery bypass grafting. They were divided into two groups: off-pump and conventional coronary artery bypass. All completed grafts were tested intraoperatively using Transit Time Flow Measurement (TTFM). Preoperative and postoperative variables of the two groups were also compared. Results There were no significant differences in sex, age, weight, acute or remote myocardial infarction, hypertension, diabetes and type of bypass grafts between the two groups. The number of bypass grafts and the assisted respiratory time of the off-pump coronary artery bypass grafting (OPCAB) group were significantly less than those of the conventional coronary artery bypass grafting (CCABG) group. The flow and pulsatile index (PI) of the left anterior descending artery bypass grafts and the right coronary artery bypass grafts were not significantly different between the OPCAB and CCABG groups. The flow of OM in the CCABG group with the multiple anastomosis site of sequential grafts was higher than that in the OPCAB group. Diffused narrow coronary artery bypass grafts in both groups had less flow.Conclusion No signficant differences in graft patency were observed in patients with triple vessel coronary artery disease who had undergone OPCAB or CCABG.

  11. PERFORMANCE MODELING AND ANALYSIS OF BLOOD FLOW IN ELASTIC ARTERIES

    Institute of Scientific and Technical Information of China (English)

    Anil Kumar; C.L. Varshney; G.C. Sharma

    2005-01-01

    Two different non-Newtonian models for blood flow are considered, first a simple power law model displaying shear thinning viscosity, and second a generalized Maxwell model displaying both shear thinning viscosity and oscillating flow viscous-elasticity. These models are used along with a Newtonian model to study sinusoidal flow of blood in rigid and elastic straight arteries in the presence of magnetic field. The elasticity of blood does not appear to influence its flow behavior under physiological conditions in the large arteries,purely viscous shear thinning model should be quite realistic for simulating blood flow under these conditions. On using the power law model with high shear rate for sinusoidal flow simulation in elastic arteries, the mean and amplitude of the flow rate were found to be lower for a power law fluid compared to Newtonian fluid for the same pressure gradient. The governing equations have been solved by Crank-Niclson scheme. The results are interpreted in the context of blood in the elastic arteries keeping the magnetic effects in view. For physiological flow simulation in the aorta, an increase in mean wall shear stress, but a reduction in peak wall shear stress were observed for power law model compared to a Newtonian fluid model for matched flow rate wave form. Blood flow in the presence of transverse magnetic field in an elastic artery is investigated and the influence of factors such as morphology and surface irregularity is evaluated.

  12. Arterial stiffness of lifelong Japanese female pearl divers.

    Science.gov (United States)

    Tanaka, Hirofumi; Tomoto, Tsubasa; Kosaki, Keisei; Sugawara, Jun

    2016-05-15

    Japanese female pearl divers called Ama specialize in free diving in the cold sea for collecting foods and pearls in oysters. Exercising in the water combined with marked bradycardia and pressor responses provides a circulatory challenge to properly buffer or cushion elevated cardiac pulsations. Because Ama perform repeated free dives throughout their lives, it is possible that they may have adapted similar arterial structure and function to those seen in diving mammals. We compared arterial stiffness of lifelong Japanese pearl divers with age-matched physically inactive adults living in the same fishing villages. A total of 115 Japanese female pearl divers were studied. Additionally, 50 physically inactive adults as well as 33 physically active adults (participating in community fitness programs) living in the same coastal villages were also studied. There were no differences in age (∼65 yr), body mass index, and brachial blood pressure between the groups. Measures of arterial stiffness, cardio-ankle vascular index and β-stiffness index were lower (P < 0.05) in pearl divers and physically active adults than in their physically inactive peers. Augmentation pressure and augmentation index adjusted for the heart rate of 75 beats/min were lower (P < 0.05) in pearl divers than in other groups. These results indicate that lifelong Japanese pearl divers demonstrate reduced arterial stiffness and arterial wave reflection compared with age-matched physically inactive peers living in the same fishing villages. PMID:26984889

  13. Internal carotid-cerebellar artery anastomosis. So-called persistent trigeminal artery variant

    Energy Technology Data Exchange (ETDEWEB)

    Tanohata, Kazunori; Maehara, Tadayuki; Noda, Masanobu; Katoh, Hiromi

    1987-09-01

    Five cases of internal carotid-cerebellar artery anastomosis are presented. These anomalous vessels are identical to the so-called persistent trigeminal artery variant (PTAV). In our cases, two superior cerebellar arteries (SCAs), two anterior inferior cerebellar arteries (AICAs) and one posterior inferior cerebellar artery (PICA) arose from the precavernous segment of the internal carotid artery. We discuss the embryolgical and neuroradiological aspects of this anomaly.

  14. Deep circumflex iliac artery as a free arterial graft for myocardial revascularization.

    Science.gov (United States)

    Yaginuma, G; Sakurai, M; Meguro, T; Ota, K; Abe, K

    2000-02-01

    When complete revascularization cannot be obtained with the internal thoracic artery and the other arterial grafts, the deep circumflex iliac artery (DCIA) may be an excellent alternative conduit. The deep circumflex iliac artery was used as a free graft for direct myocardial revascularization in 4 patients from January to July 1999. We describe our experience with this arterial conduit, review the anatomy of the artery, and present our harvesting technique. PMID:10735725

  15. Clinical Outcomes After Drug-Eluting Stents Versus Coronary Artery Bypass Surgery in High Surgical Risk Patients With Left Main or Three-Vessel Coronary Artery Disease

    OpenAIRE

    Tonga Nfor; Kambiz Shetabi; Wael Hassan; Quinta Nfor; Jayant Khitha; Anjan Gupta; Tanvir Bajwa; Suhail Allaqaband

    2015-01-01

    Purpose: Previous studies comparing percutaneous coronary intervention (PCI) with coronary artery bypass graft surgery (CABG) in patients with unprotected left main or three-vessel coronary artery disease (LM-3VD) have excluded patients at high surgical risk. We compared clinical outcomes after PCI with drug-eluting stents to CABG in high surgical risk patients with LM-3VD. Methods: Patients with symptomatic LM-3VD who had Society of Thoracic Surgeons (STS)-predicted operative mortality >...

  16. Livergraftvascularvariantwith 3 extra-hepatic arteries

    Institute of Scientific and Technical Information of China (English)

    Paulo N Martins

    2010-01-01

     Vascular anatomy of the liver is varied, and the"standard"anatomy is seen in 55%-80%of cases. It is very important that extrahepatic arteries are identiifed precisely at the time of graft procurement to avoid injuries that might compromise the liver function. In the present case the liver donor had the vascular anatomy of Michels type Ⅶ, e.g. a hepatic artery originating from the celiac trunk and going to the left lobe, an accessory left hepatic artery coming from the left gastric artery, and a replaced right hepatic artery coming from the superior mesenteric artery. This pattern of vascular supply is uncommon, representing less than 5%of cases. The replaced hepatic artery was reconstructed in the back-table with polypropylene suture 7.0 by connecting it to the stump of the splenic artery, and the celiac trunk of the graft was anastomosed to the recipient common hepatic artery.

  17. Presence of a median cubital arterial arch associated with high origin of radial artery

    Directory of Open Access Journals (Sweden)

    Shetty SD

    2010-09-01

    Full Text Available Occurrence of a median cubital arterial arch is very rare. We saw a superficially placed median cubital arterial arch associated with high level of origin of radial artery. The radial artery took origin from the brachial artery in the upper third of the arm and crossed median nerve and ulnar artery from medial to lateral side. The course and distribution of the vessels in the forearm was normal. In the cubital fossa, the radial and ulnar arteries were connected to each other by an arterial arch. The variations reported here are very useful for the radiologists as these variations can cause problems in invasive procedures.

  18. Accurate finite difference beam propagation method for complex integrated optical structures

    DEFF Research Database (Denmark)

    Rasmussen, Thomas; Povlsen, Jørn Hedegaard; Bjarklev, Anders Overgaard

    1993-01-01

    A simple and effective finite-difference beam propagation method in a z-varying nonuniform mesh is developed. The accuracy and computation time for this method are compared with a standard finite-difference method for both the 3-D and 2-D versions......A simple and effective finite-difference beam propagation method in a z-varying nonuniform mesh is developed. The accuracy and computation time for this method are compared with a standard finite-difference method for both the 3-D and 2-D versions...

  19. Endothelial dysfunction, carotid artery plaque burden, and conventional exercise-induced myocardial ischemia as predictors of coronary artery disease prognosis

    Directory of Open Access Journals (Sweden)

    Ishihara Masayuki

    2008-12-01

    Full Text Available Abstract Background While both flow-mediated vasodilation (FMD in the brachial artery (BA, which measures endothelium-dependent vasodilatation, and intima-media thickness (IMT in the carotid artery are correlated with the prognosis of coronary artery disease (CAD, it is not clear which modality is a better predictor of CAD. Furthermore, it has not been fully determined whether either of these modalities is superior to conventional ST-segment depression on exercise stress electrocardiogram (ECG as a predictor. Thus, the goal of the present study was to compare the predictive value of FMD, IMT, and stress ECG for CAD prognosis. Methods and Results A total of 103 consecutive patients (62 ± 9 years old, 79 men with clinically suspected CAD had FMD and nitroglycerin-induced dilation (NTG-D in the BA, carotid artery IMT measurement using high-resolution ultrasound, and exercise treadmill testing. The 73 CAD patients and 30 normal coronary patients were followed for 50 ± 15 months. Fifteen patients had coronary events during this period (1 cardiac death, 2 non-fatal myocardial infarctions, 3 acute heart failures, and 9 unstable anginas. On Kaplan-Meier analysis, only FMD and stress ECG were significant predictors for cardiac events. Conclusion Brachial endothelial function as reflected by FMD and conventional exercise stress testing has comparable prognostic value, whereas carotid artery plaque burden appears to be less powerful for predicting future cardiac events.

  20. Exponential Finite-Difference Technique

    Science.gov (United States)

    Handschuh, Robert F.

    1989-01-01

    Report discusses use of explicit exponential finite-difference technique to solve various diffusion-type partial differential equations. Study extends technique to transient-heat-transfer problems in one dimensional cylindrical coordinates and two and three dimensional Cartesian coordinates and to some nonlinear problems in one or two Cartesian coordinates.