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Sample records for aortic cusp guided

  1. Aortic cusp extension valvuloplasty: repair with an extracellular patch

    Science.gov (United States)

    Pawlak, Szymon; Śliwka, Joanna; Urlik, Maciej; Maruszewski, Marcin; Kukulski, Tomasz; Nożyński, Jerzy; Zembala, Marian

    2015-01-01

    Introduction The proportion of valve repair procedures is increasing in experienced centers. The aim of the study was to assess the clinical and echocardiographic outcomes after aortic valve reconstruction with a novel surgical technique. Material and methods The study group consisted of 30 patients (23 male and 7 female) at a mean age of 35 ± 14 years. In patients with aortic root aneurysm the reimplantation or Florida sleeve technique was used. A sub-commissural annuloplasty, plication of the free edge of the cusp, shaving, and commissurotomy were performed. At this stage of surgery aortic repair was then attempted by cusp extension. Since 2013 the strips have been tailored from extracellular matrix. Results The mean aortic cross-clamp time was 90 ± 32 min. The mean cardiopulmonary bypass time was 126 ± 38 min. There was no in-hospital death. Re-exploration for bleeding was required in 1 patient. During follow-up, 1 patient needed reoperation at 1 year due to endocarditis. All patients remained alive in New York Heart Association (NYHA) functional class I. The echocardiographic findings remained unchanged in all cases during follow-up. Conclusions Our modification of aortic valve repair results in a good outcome. PMID:26855646

  2. A fibrous band associated with the non-coronary aortic valve cusp in a dog.

    Science.gov (United States)

    Ajithdoss, Dharani K; Arenas-Gamboa, Angela M; Edwards, John F

    2011-06-01

    A fibrous band connecting the middle of the free edge (nodulus Arantii) of the non-coronary aortic valve cusp to the ascending aorta just above the level of the non-coronary sinus of Valsalva was observed in an asymptomatic, 11-year-old, male Border Collie. The fibrous band was unrelated to the cause of the death in this dog. Such fibrous bands are usually reported in humans with congenital bicuspid aortic valves. To our knowledge, this is the first report of a fibrous band in the aortic valve in a domestic animal. PMID:21641896

  3. Streptococcus agalactiae infective endocarditis complicated by large vegetations at aortic valve cusps along with intracoronary extension: An autopsy case report.

    Science.gov (United States)

    Ro, Ayako

    2016-01-01

    Streptococcus agalactiae infective endocarditis is a rare condition with high mortality owing to complications of large vegetations and systemic emboli. A 49-year-old man was found dead in his house. He had a history of hepatic cirrhosis and had been diagnosed with type 2 diabetes 2years previously. He had presented with a high fever 10days before his death. An autopsy revealed 50mL of purulent pericardial effusion, and S. agalactiae was detected from the culture of this pericardial effusion. Two slender rope-like vegetations were present at the right aortic valve cusp and noncoronary aortic valve cusp. The vegetation at the right aortic valve cusp extended into the right coronary artery. The right coronary artery was broadly occluded by white rod-like material. The mitral valves were also affected, and the posterior papillary muscle was ruptured. Myocardial infarction was not observed. Systemic microscopic Gram-positive bacterial masses were observed in several organs. The death was attributed to acute myocardial ischemia caused by occlusive intracoronary extension of the vegetation at the proximal right coronary artery. PMID:26926519

  4. Imaging analysis of collagen fiber networks in cusps of porcine aortic valves: effect of their local distribution and alignment on valve functionality.

    Science.gov (United States)

    Mega, Mor; Marom, Gil; Halevi, Rotem; Hamdan, Ashraf; Bluestein, Danny; Haj-Ali, Rami

    2016-07-01

    The cusps of native aortic valve (AV) are composed of collagen bundles embedded in soft tissue, creating a heterogenic tissue with asymmetric alignment in each cusp. This study compares native collagen fiber networks (CFNs) with a goal to better understand their influence on stress distribution and valve kinematics. Images of CFNs from five porcine tricuspid AVs are analyzed and fluid-structure interaction models are generated based on them. Although the valves had similar overall kinematics, the CFNs had distinctive influence on local mechanics. The regions with dilute CFN are more prone to damage since they are subjected to higher stress magnitudes. PMID:26406926

  5. Triglycidylamine Crosslinking of Porcine Aortic Valve Cusps or Bovine Pericardium Results in Improved Biocompatibility, Biomechanics, and Calcification Resistance : Chemical and Biological Mechanisms

    OpenAIRE

    Connolly, Jeanne M.; Alferiev, Ivan; Clark-Gruel, Jocelyn N.; Eidelman, Naomi; Sacks, Michael; Palmatory, Elizabeth; Kronsteiner, Allyson; DeFelice, Suzanne; Xu, Jie; Ohri, Rachit; Narula, Navneet; Vyavahare, Narendra; Levy, Robert J.

    2005-01-01

    We investigated a novel polyepoxide crosslinker that was hypothesized to confer both material stabilization and calcification resistance when used to prepare bioprosthetic heart valves. Triglycidylamine (TGA) was synthesized via reacting epichlorhydrin and NH3. TGA was used to crosslink porcine aortic cusps, bovine pericardium, and type I collagen. Control materials were crosslinked with glutaraldehyde (Glut). TGA-pretreated materials had shrink temperatures comparable to Glut fixation. Howev...

  6. Cusp Injection Experiment

    International Nuclear Information System (INIS)

    A brief survey is given of the characteristics of the β = 1 cusped configuration and the experimental techniques for establishing hot field-free cusped plasmas. Results from the cusp compression experiments at the Culham Laboratory are summarised and it is concluded that wall and external plasma effects make it extremely difficult to obtain a cusp hole of size less than an ion gyro-diameter by the compression method. An injection technique is described in which hot field-free plasma is transferred from a conical theta-pinch gun through a uniform magnetic guide field into a cusped field region where directed energy is randomised by collision with counter-streaming plasma. Experimental results are presented on gun development, on the injection of plasma into guide fields and on the stability of flow of plasma ''spears'' along guide fields. Preliminary measurements on plasma trapping in a cusped region are reported. Experiments on the collision of plasmas in guide field and zero field show the importance of very low magnitude trapped magnetic fields in causing strong interaction and randomisation of directed energy. The study of a magnetic mirror plasma formed by colliding plasma spears indicates that thermal conductivity may be the major energy loss process. (author)

  7. Loss of Guide Wire: A Rare Complication of Intra-Aortic Balloon Pump Insertion

    Directory of Open Access Journals (Sweden)

    Manouchehr Hekmat

    2015-10-01

    Full Text Available At the final stages of a coronary artery bypass graft operation on a 64-year-old man, an experienced physician attempted to insert an intra-aortic balloon pump into the femoral artery via the Seldinger technique. However, while the balloon pump was being passed over the guide wire, the latter was completely lost.The guide wire should be held at the tip at all times to prevent passage into the vessel. Strict adherence to this rule will prevent guide-wire loss, which is, albeit rare and completely avoidable, a potentially life-threatening complication of central vein or artery catheterization, with reported fatality rates of up to 20% when the whole wire is lost. The literature contains several reports on guide-wire loss during central venous, arterial, and hemodialysis catheterization, but we report for the first time the loss of a guide wire as a rare complication of intra-aortic balloon pump insertion.

  8. A Practical Guide to Clinical Management of Thoracic Aortic Disease.

    Science.gov (United States)

    Bradley, Timothy J; Alvarez, Nanette A M; Horne, S Gabrielle

    2016-01-01

    Physicians and surgeons faced with patients with thoracic aortic disease (TAD) need to determine the underlying diagnosis to facilitate decisions regarding appropriate investigations as well as which other specialists to involve, when to start medical therapy, when to refer for surgery, and how to plan follow-up and family screening. Increased understanding of conditions predisposing to thoracic aortic aneurysm (TAA) provides the opportunity for more personalized care. However, given advances in the genetics of TAD, clinicians are now faced with an expanded and often confusing list of associated differential diagnoses. We present a practical guide to managing patients with TAD based on current knowledge and guidelines. Important "flags" on history taking and "tips" to diagnosis on physical examination along with what investigations to order and what referrals to request are discussed. Need for medical therapy, indications for surgical repair, and planning long-term follow-up of TAD are determined by age, the underlying TAD diagnosis, previous vascular history in the patient or other family members (or both), aortic dimensions and growth rate, and any coexisting cardiovascular disease. Although medications may slow the progression of TAA, effective aortic surveillance and timely elective surgical repair remain the mainstays of prevention of acute aortic complications. Emergent repair of acute aortic dissection carries a far worse prognosis. Taking a practical approach to the management of TAD allows for standardized assessment and implementation of current best practice clinical guidelines. Ongoing discovery of new genes, better medical therapies, and innovative surgical techniques necessitate constantly adapting knowledge and integrating it into everyday clinical practice. PMID:26724515

  9. The TEVAR App: a contemporary guide to thoracic endovascular aortic repair†.

    Science.gov (United States)

    Rylski, Bartosz; Czerny, Martin; Südkamp, Michael; Siepe, Matthias; Beyersdorf, Friedhelm

    2016-02-01

    There is a growing number of devices used for thoracic endovascular aortic repair (TEVAR). The designs of stent grafts and their delivery systems differ substantially. The success of TEVAR is based on the correct use of stent graft delivery systems, the identification and understanding of radiopaque markers, and the stent graft's accurate placement. In this brief communication, we introduce the TEVAR App-a novel guide for thoracic endovascular aortic repair. It is a tool that provides key information that is quick to access and easy to understand on the thoracic aortic stent grafts currently available. It includes instructions for use, animations demonstrating the stent grafts' deployment, troubleshooting information, size tables, the locations of radiopaque markers, stent graft and delivery system photos, chest X-rays, and information on magnetic resonance safety and compatibility. Furthermore, it contains the TEVAR Calculator, which assists one in planning stent graft size according to individual aortic dimensions and oversizing factors. The TEVAR App is cost-free, and its development has not been supported financially by any industry. It is a non-profit project that aims to educate and help physicians performing TEVARs. PMID:26541961

  10. Congenital aortic regurgitation in a child with a tricuspid non-stenotic aortic valve.

    OpenAIRE

    Hashimoto, R; Miyamura, H; Eguchi, S

    1984-01-01

    After follow up for seven years a 10 year old boy with congenital aortic regurgitation was found to have a tricuspid non-stenotic aortic valve at operation. The right coronary cusp was dysplastic, thickened, and contracted; the gap between its free margin and aortic wall was bridged with two fibrous bands; and the left coronary and non-coronary cusps were almost normal. The aortic valve was replaced with a prosthesis (St Jude Medical No 23), and the postoperative course was uneventful.

  11. Bicuspid aortic valves: Diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT

    International Nuclear Information System (INIS)

    Objectives: To assess the diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT for bicuspid aortic valves. Materials and methods: The standard axial chest CT scans of 20 patients with known bicuspid aortic valves were blindly, randomly analyzed for (i) the appearance of the valve cusps, (ii) the largest aortic sinus area, (iii) the longest aortic cusp length, (iv) the thickest aortic valve cusp and (v) valve calcification. A second blinded reader independently analyzed the appearance of the valve cusps. Forty-two age- and sex-matched patients with known tricuspid aortic valves were used as controls. Retrospectively ECG-gated cardiac CT multiphase reconstructions of the aortic valve were used as the gold-standard. Results: Fourteen (21%) scans were scored as unevaluable (7 bicuspid, 7 tricuspid). Of the remainder, there were 13 evaluable bicuspid valves, ten of which showed an aortic valve line sign, while the remaining three showed a normal Mercedes-Benz appearance owing to fused valve cusps. The 35 evaluable tricuspid aortic valves all showed a normal Mercedes-Benz appearance (P = 0.001). Kappa analysis = 0.62 indicating good interobserver agreement for the aortic valve cusp appearance. Aortic sinus areas, aortic cusp lengths and aortic cusp thicknesses of ≥3.8 cm2, 3.2 cm and 1.6 mm respectively on standard axial chest CT best distinguished bicuspid from tricuspid aortic valves (P < 0.0001 for all). Of evaluable scans, the sensitivity, specificity, positive and negative predictive values of standard axial chest CT in diagnosing bicuspid aortic valves was 77% (CI 0.54–1.0), 100%, 100% and 70% respectively. Conclusion: The aortic valve is evaluable in approximately 80% of standard chest 64-slice CT scans. Bicuspid aortic valves may be diagnosed on evaluable scans with good diagnostic accuracy. An aortic valve line sign, enlarged aortic sinuses and elongated, thickened valve cusps are specific CT

  12. Facial talon cusps.

    LENUS (Irish Health Repository)

    McNamara, T

    1997-12-01

    This is a report of two patients with isolated facial talon cusps. One occurred on a permanent mandibular central incisor; the other on a permanent maxillary canine. The locations of these talon cusps suggests that the definition of a talon cusp include teeth in addition to the incisor group and be extended to include the facial aspect of teeth.

  13. Self-bending symmetric cusp beams

    Science.gov (United States)

    Gong, Lei; Liu, Wei-Wei; Ren, Yu-Xuan; Lu, Yao; Li, Yin-Mei

    2015-12-01

    A type of self-bending symmetric cusp beams with four accelerating intensity maxima is theoretically and experimentally presented. Distinguished from the reported regular polygon beams, the symmetric cusp beams simultaneously exhibit peculiar features of natural autofocusing and self-acceleration during propagation. Further, such beams take the shape of a fine longitudinal needle-like structure at the focal region and possess the strong ability of self-healing over obstacles. All these intriguing properties were verified experimentally. Particularly, the spatial profile of the reconstructed beam exhibits spatially sculpted optical structure with four siamesed curved arms. Thus, we anticipate that the structured beam will benefit optical guiding and optofluidics in surprising ways.

  14. Self-bending symmetric cusp beams

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Lei; Liu, Wei-Wei; Lu, Yao; Li, Yin-Mei, E-mail: liyinmei@ustc.edu.cn [Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui Province 230026 (China); Ren, Yu-Xuan [Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132 (United States)

    2015-12-07

    A type of self-bending symmetric cusp beams with four accelerating intensity maxima is theoretically and experimentally presented. Distinguished from the reported regular polygon beams, the symmetric cusp beams simultaneously exhibit peculiar features of natural autofocusing and self-acceleration during propagation. Further, such beams take the shape of a fine longitudinal needle-like structure at the focal region and possess the strong ability of self-healing over obstacles. All these intriguing properties were verified experimentally. Particularly, the spatial profile of the reconstructed beam exhibits spatially sculpted optical structure with four siamesed curved arms. Thus, we anticipate that the structured beam will benefit optical guiding and optofluidics in surprising ways.

  15. Cusps in interfacial problems

    CERN Document Server

    Fontelos, J Eggers M A

    2009-01-01

    A wide range of equations related to free surface motion in two dimensions exhibit the formation of cusp singularities either in time, or as function of a parameter. We review a number of specific examples, relating in particular to fluid flow and to wave motion, and show that they exhibit one of two types of singularity: cusp or swallowtail. This results in a universal scaling form of the singularity, and permits a tentative classification.

  16. Bicuspid aortic valves: Diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, David J., E-mail: david.murphy@st-vincents.ie [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); McEvoy, Sinead H., E-mail: s.mcevoy@st-vincents.ie [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); Iyengar, Sri, E-mail: sri.iyengar@nhs.net [Department of Radiology, Plymouth Hospitals NHS Trust, Plymouth Devon PL6 8DH (United Kingdom); Feuchtner, Gudrun, E-mail: Gudrun.Feuchtner@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Anichstr. 35, A-6020 Innsbruck (Austria); Cury, Ricardo C., E-mail: r.cury@baptisthealth.net [Department of Radiology, Baptist Cardiac and Vascular Institute, 8900 North Kendall Drive, Miami, FL 33176 (United States); Roobottom, Carl, E-mail: carl.roobottom@nhs.net [Department of Radiology, Plymouth Hospitals NHS Trust, Plymouth Devon PL6 8DH (United Kingdom); Plymouth University Peninsula Schools of Medicine and Dentistry (United Kingdom); Baumueller, Stephan, E-mail: Hatem.Alkadhi@usz.ch [Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland); Alkadhi, Hatem, E-mail: stephan.baumueller@usz.ch [Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland); Dodd, Jonathan D., E-mail: jonniedodd@gmail.com [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland)

    2014-08-15

    Objectives: To assess the diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT for bicuspid aortic valves. Materials and methods: The standard axial chest CT scans of 20 patients with known bicuspid aortic valves were blindly, randomly analyzed for (i) the appearance of the valve cusps, (ii) the largest aortic sinus area, (iii) the longest aortic cusp length, (iv) the thickest aortic valve cusp and (v) valve calcification. A second blinded reader independently analyzed the appearance of the valve cusps. Forty-two age- and sex-matched patients with known tricuspid aortic valves were used as controls. Retrospectively ECG-gated cardiac CT multiphase reconstructions of the aortic valve were used as the gold-standard. Results: Fourteen (21%) scans were scored as unevaluable (7 bicuspid, 7 tricuspid). Of the remainder, there were 13 evaluable bicuspid valves, ten of which showed an aortic valve line sign, while the remaining three showed a normal Mercedes-Benz appearance owing to fused valve cusps. The 35 evaluable tricuspid aortic valves all showed a normal Mercedes-Benz appearance (P = 0.001). Kappa analysis = 0.62 indicating good interobserver agreement for the aortic valve cusp appearance. Aortic sinus areas, aortic cusp lengths and aortic cusp thicknesses of ≥3.8 cm{sup 2}, 3.2 cm and 1.6 mm respectively on standard axial chest CT best distinguished bicuspid from tricuspid aortic valves (P < 0.0001 for all). Of evaluable scans, the sensitivity, specificity, positive and negative predictive values of standard axial chest CT in diagnosing bicuspid aortic valves was 77% (CI 0.54–1.0), 100%, 100% and 70% respectively. Conclusion: The aortic valve is evaluable in approximately 80% of standard chest 64-slice CT scans. Bicuspid aortic valves may be diagnosed on evaluable scans with good diagnostic accuracy. An aortic valve line sign, enlarged aortic sinuses and elongated, thickened valve cusps are specific CT

  17. Cusps of Picard modular surfaces

    OpenAIRE

    Stover, Matthew

    2010-01-01

    We determine the number of cusps of minimal Picard modular surfaces. The proof also counts cusps of other Picard modular surfaces of arithmetic interest. Consequently, for each N > 0 there are finitely many commensurability classes of nonuniform arithmetic lattices in SU(2, 1) that contain an N-cusped surface. We also discuss a higher-rank analogue.

  18. Fused aortic valve without an elliptical-shaped systolic orifice in patients with severe aortic stenosis: cardiac computed tomography is useful for differentiation between bicuspid aortic valve with raphe and tricuspid aortic valve with commissural fusion

    International Nuclear Information System (INIS)

    The objective is to determine cardiac computed tomography (CCT) features capable of differentiating between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) in severe aortic stenosis (AS) patients with fused cusp and without elliptical-shaped systolic orifices. We retrospectively enrolled 53 patients who had severe AS with fused cusps and without an elliptical-shaped systolic orifice on CCT and who had undergone surgery. CCT features were analyzed using: (1) aortic valve findings including cusp size, cusp area, opening shape, midline calcification, fusion length, calcium volume score, and calcium grade; (2) diameters of ascending and descending aorta, and main pulmonary artery; and (3) rheumatic mitral valve findings. The variables were evaluated using univariate and multivariate logistic regression analyses. At surgery, 19 patients had BAV and 34 had TAV. CCT features including uneven cusp size, uneven cusp area, round-shaped systolic orifice, longer cusp fusion, and dilatation of ascending aorta were significantly associated with BAV (P < 0.05). In particular, fusion length (OR, 1.76; P = 0.001), uneven cusp area (OR, 10.46; P = 0.012), and midline calcification (OR, 0.08; P = 0.013) were strongly associated with BAV. CCT provides diagnostic clues that helps differentiate between BAV with raphe and TAV with commissural fusion in patients with severe AS. (orig.)

  19. Fused aortic valve without an elliptical-shaped systolic orifice in patients with severe aortic stenosis: cardiac computed tomography is useful for differentiation between bicuspid aortic valve with raphe and tricuspid aortic valve with commissural fusion

    Energy Technology Data Exchange (ETDEWEB)

    Bak, So Hyeon; Ko, Sung Min [Konkuk University School of Medicine, Departments of Radiology, Konkuk University Medical Center, Seoul (Korea, Republic of); Song, Meong Gun; Shin, Je Kyoun; Chee, Hyun Kun; Kim, Jun Suk [Konkuk University School of Medicine, Departments of Thoracic Surgery, Konkuk University Medical Center, Seoul (Korea, Republic of)

    2015-04-01

    The objective is to determine cardiac computed tomography (CCT) features capable of differentiating between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) in severe aortic stenosis (AS) patients with fused cusp and without elliptical-shaped systolic orifices. We retrospectively enrolled 53 patients who had severe AS with fused cusps and without an elliptical-shaped systolic orifice on CCT and who had undergone surgery. CCT features were analyzed using: (1) aortic valve findings including cusp size, cusp area, opening shape, midline calcification, fusion length, calcium volume score, and calcium grade; (2) diameters of ascending and descending aorta, and main pulmonary artery; and (3) rheumatic mitral valve findings. The variables were evaluated using univariate and multivariate logistic regression analyses. At surgery, 19 patients had BAV and 34 had TAV. CCT features including uneven cusp size, uneven cusp area, round-shaped systolic orifice, longer cusp fusion, and dilatation of ascending aorta were significantly associated with BAV (P < 0.05). In particular, fusion length (OR, 1.76; P = 0.001), uneven cusp area (OR, 10.46; P = 0.012), and midline calcification (OR, 0.08; P = 0.013) were strongly associated with BAV. CCT provides diagnostic clues that helps differentiate between BAV with raphe and TAV with commissural fusion in patients with severe AS. (orig.)

  20. Aortic stenosis

    Science.gov (United States)

    ... stenosis; Valvular aortic stenosis; Congenital heart - aortic stenosis; Rheumatic fever - aortic stenosis Images Aortic stenosis Heart valves References Carabello BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  1. Aortic insufficiency

    Science.gov (United States)

    ... Heart valve - aortic regurgitation; Valvular disease - aortic regurgitation; AI - aortic insufficiency ... BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: ...

  2. Transretroperitoneal CT-guided Embolization of Growing Internal Iliac Artery Aneurysm after Repair of Abdominal Aortic Aneurysm: A Transretroperitoneal Approach with Intramuscular Lidocaine Injection Technique

    International Nuclear Information System (INIS)

    This study was designed to evaluate the efficacy and safety of CT-guided embolization of internal iliac artery aneurysm (IIAA) after repair of abdominal aortic aneurysm by transretroperitoneal approach using the lidocaine injection technique to iliacus muscle, making window for safe needle path for three patients for whom CT-guided embolization of IIAA was performed by transretroperitoneal approach with intramuscular lidocaine injection technique. Transretroperitoneal access to the IIAA was successful in all three patients. In all three patients, the IIAA was first embolized using microcoils. The aneurysmal sac was then embolized with glue and coils without complication. With a mean follow-up of 7 months, the volume of the IIAAs remained stable without residual endoleaks. Transretroperitoneal CT-guided embolization of IIAA using intramuscular lidocaine injection technique is effective, safe, and results in good outcome

  3. Transretroperitoneal CT-guided Embolization of Growing Internal Iliac Artery Aneurysm after Repair of Abdominal Aortic Aneurysm: A Transretroperitoneal Approach with Intramuscular Lidocaine Injection Technique

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joon Young, E-mail: pjy1331@hanmail.net; Kim, Shin Jung, E-mail: witdd2@hanmail.net; Kim, Hyoung Ook, E-mail: chaos821209@hanmail.net [Chonnam National University Hospital, Department of Radiology (Korea, Republic of); Kim, Yong Tae, E-mail: mono-111@hanmail.net [Chonnam National University Hwasun Hospital, Department of Radiology (Korea, Republic of); Lim, Nam Yeol, E-mail: apleseed@hanmail.net; Kim, Jae Kyu, E-mail: kjkrad@jnu.ac.kr [Chonnam National University Hospital, Department of Radiology (Korea, Republic of); Chung, Sang Young, E-mail: sycpvts@jnu.ac.kr; Choi, Soo Jin Na, E-mail: choisjn@jnu.ac.kr; Lee, Ho Kyun, E-mail: mhaha@hanmail.net [Chonnam National University Hospital, Department of Surgery (Korea, Republic of)

    2015-02-15

    This study was designed to evaluate the efficacy and safety of CT-guided embolization of internal iliac artery aneurysm (IIAA) after repair of abdominal aortic aneurysm by transretroperitoneal approach using the lidocaine injection technique to iliacus muscle, making window for safe needle path for three patients for whom CT-guided embolization of IIAA was performed by transretroperitoneal approach with intramuscular lidocaine injection technique. Transretroperitoneal access to the IIAA was successful in all three patients. In all three patients, the IIAA was first embolized using microcoils. The aneurysmal sac was then embolized with glue and coils without complication. With a mean follow-up of 7 months, the volume of the IIAAs remained stable without residual endoleaks. Transretroperitoneal CT-guided embolization of IIAA using intramuscular lidocaine injection technique is effective, safe, and results in good outcome.

  4. Fitting the Cusp Catastrophe in R: A cusp Package Primer

    Directory of Open Access Journals (Sweden)

    Raoul P. P. P. Grasman

    2009-11-01

    Full Text Available Of the seven elementary catastrophes in catastrophe theory, the “cusp” model is the most widely applied. Most applications are however qualitative. Quantitative techniques for catastrophe modeling have been developed, but so far the limited availability of flexible software has hindered quantitative assessment. We present a package that implements and extends the method of Cobb (Cobb and Watson 1980; Cobb, Koppstein, and Chen 1983, and makes it easy to quantitatively fit and compare different cusp catastrophe models in a statistically principled way. After a short introduction to the cusp catastrophe, we demonstrate the package with two instructive examples.

  5. Annular sizing using real-time three-dimensional intracardiac echocardiography-guided trans-catheter aortic valve replacement

    Science.gov (United States)

    Rendon, Alejandro; Hamid, Tahir; Kanaganayagam, Gajen; Karunaratne, Devinda; Mahadevan, Vaikom S

    2016-01-01

    Objective Transcatheter aortic valve replacement (TAVR) has been established as an alternative therapy for patients with severe aortic stenosis who are unfit for the surgical aortic valve replacements. Pre and periprocedural imaging for the TAVR procedure is the key to procedural success. Currently transesophageal echocardiography (TOE), including real-time three-dimensional (RT-3D) imaging TOE, has been used for peri-interventional monitoring and guidance for TAVR. We describe our initial experience with real-time three-dimensional intracardiac echocardiography (RT-3DICE), imaging technology for the use in the TAVR procedure. Methods We used RT-3DICE using an ACUSON SC2000 2.0v (Siemens Medical Solution), and a 10F AcuNav V catheter (Siemens-Acuson, Inc, Mountain View, California, USA) in addition to preoperative multislice CT (MSCT) in total of five patients undergoing TAVR procedure. Results Aortic annulus and sinus of valsalva diameters were measured using RT-3DICE. Aortic valve measurements obtained using RT-3DICE are comparable to those obtained using MSCT with no significant difference in our patients. Conclusions This small study of five patients shows the safe use of RT-3DICE in TAVR Procedure and may help the procedures performed under local anaesthesia without the need for TOE. PMID:27158522

  6. Estudo comparativo da eficácia do etanol e do ácido L-glutâmico na prevenção da calcificação das cúspides e parede aórtica porcina: estudo experimental em ratos Comparative study on the efficacy of ethanol and of l-glutamic acid for preventing calcification of pig cusps and aortic wall: experimental study in rats

    Directory of Open Access Journals (Sweden)

    George Ronald Soncini da ROSA

    2002-06-01

    álcio/ mg tecido, E80% 30 dias (9,47 ± 2,59mg cálcio/mg tecido e E80% 60 dias (23,56±7,75 mg cálcio/mg tecido no grupo de AG 0,8% 15 dias (4,31±0,85 mg cálcio/mg tecido, AG 0,8% 30 dias (7,69±1,48 mg cálcio/mg tecido e AG 0,8% 60 dias (20,50± 1,22 mg cálcio/mg tecido com o grupo controle GDA 15 dias (7,34±1,32 mg cálcio/mg tecido, GDA 30 dias (9,28±0,76 mg cálcio/mg tecido e GDA 60 dias (27,60±1,08 mg cálcio/mg tecido. Na avaliação microscópica da cúspide aórtica houve uma progressiva calcificação naquelas submetidas à fixação com GDA. Este processo foi parcialmente encontrado com o AG 0,8% e totalmente ausente com o E80%. Quanto à avaliação referente aos segmentos da parede aórtica, também evidenciou-se progressiva calcificação, não sendo inibida pelos tratamentos com AG 0,8% e E80%. CONCLUSÕES: O pré-tratamento com etanol a 80% inibiu a calcificação nas cúspides aórticas porcinas, entretanto, não teve a mesma eficácia na parede aórtica. Contudo, o ácido L-glutâmico a 0,8% demonstrou minimizar a calcificação na parede aórtica. Estudos devem ser feitos para evidenciar se a ação anticalcificante do etanol a 80% mantém-se nas biopróteses aórticas porcinas se estas forem implantadas no sistema circulatório.INTRODUCTION: The glutataldehyde (GDA treated pigs cusps are one of most employed tissues in bioprosthesis, but is late post-implant calcification is main cause of its failure. BACKGROUND: This study aims at comparing and analyzing two methods (ethanol 80% and l-glutamic acid 0.8% to prevent calcification in pig cusps and aortic wall implanted subcutaneously in rats, the cusps and aortic wall segments of the control were in glutaraldehyde (GDA, during a 15, 30 and 60 days period after the implant. MATERIAL AND METHODS: We used 45 young rats, distributed in 3 groups of 15 rats each, which in turn were subdivided in 3 subgroups of 5 rats each, in which we implanted one cusp and one aortic wall segment in 2 subcutaneous

  7. THE CUSP ECR ION SOURCE

    OpenAIRE

    Sudlitz, K.

    1989-01-01

    A Cusp ECR ion source is being developed in Warsaw University to be used on U-200 heavy ion cyclotron. The main goal of the work is the test of the idea of an ECR source constructed without permanent magnets and by means of an inexpensive 2.45GHz generator.

  8. Cassini observations of Saturn's southern polar cusp

    CERN Document Server

    Arridge, C S; Achilleos, N; Bogdanova, Y V; Bunce, E J; Cowley, S W H; Fazakerley, A N; Khurana, K K; Lamy, L; Leisner, J S; Roussos, E; Russell, C T; Zarka, P; Coates, A J; Dougherty, M K; Jones, G H; Krimigis, S M; Krupp, N

    2016-01-01

    The magnetospheric cusps are important sites of the coupling of a magnetosphere with the solar wind. The combination of both ground- and space-based observations at Earth have enabled considerable progress to be made in understanding the terrestrial cusp and its role in the coupling of the magnetosphere to the solar wind via the polar magnetosphere. Voyager 2 fully explored Neptune's cusp in 1989 but highly inclined orbits of the Cassini spacecraft at Saturn present the most recent opportunity to repeatedly studying the polar magnetosphere of a rapidly rotating planet. In this paper we discuss observations made by Cassini during two passes through Saturn's southern polar magnetosphere. Our main findings are that i) Cassini directly encounters the southern polar cusp with evidence for the entry of magnetosheath plasma into the cusp via magnetopause reconnection, ii) magnetopause reconnection and entry of plasma into the cusp can occur over a range of solar wind conditions, and iii) double cusp morphologies are...

  9. Towards real-time cardiovascular magnetic resonance-guided transarterial aortic valve implantation: In vitro evaluation and modification of existing devices

    Directory of Open Access Journals (Sweden)

    Ladd Mark E

    2010-10-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR is considered an attractive alternative for guiding transarterial aortic valve implantation (TAVI featuring unlimited scan plane orientation and unsurpassed soft-tissue contrast with simultaneous device visualization. We sought to evaluate the CMR characteristics of both currently commercially available transcatheter heart valves (Edwards SAPIEN™, Medtronic CoreValve® including their dedicated delivery devices and of a custom-built, CMR-compatible delivery device for the Medtronic CoreValve® prosthesis as an initial step towards real-time CMR-guided TAVI. Methods The devices were systematically examined in phantom models on a 1.5-Tesla scanner using high-resolution T1-weighted 3D FLASH, real-time TrueFISP and flow-sensitive phase-contrast sequences. Images were analyzed for device visualization quality, device-related susceptibility artifacts, and radiofrequency signal shielding. Results CMR revealed major susceptibility artifacts for the two commercial delivery devices caused by considerable metal braiding and precluding in vivo application. The stainless steel-based Edwards SAPIEN™ prosthesis was also regarded not suitable for CMR-guided TAVI due to susceptibility artifacts exceeding the valve's dimensions and hindering an exact placement. In contrast, the nitinol-based Medtronic CoreValve® prosthesis was excellently visualized with delineation even of small details and, thus, regarded suitable for CMR-guided TAVI, particularly since reengineering of its delivery device toward CMR-compatibility resulted in artifact elimination and excellent visualization during catheter movement and valve deployment on real-time TrueFISP imaging. Reliable flow measurements could be performed for both stent-valves after deployment using phase-contrast sequences. Conclusions The present study shows that the Medtronic CoreValve® prosthesis is potentially suited for real-time CMR-guided placement

  10. Understanding the focusing of charged particle for 2D sheet beam in a cusped magnetic field

    CERN Document Server

    Banerjee, Tusharika S; Reddy, K T V

    2016-01-01

    The requirement of axial magnetic field for focusing and transportation of sheet beam using cusped magnets is less as compared to solenoid magnetic fields which is uniform. There is often some confusion about how a cusped magnetic field focuses high current density sheet beam because it is generally understood that non-uniform magnetic field cannot guide the particle beam along its axis of propagation .In this paper, we perform simple analysis of the dynamics of sheet beam in a cusped magnetic field with single electron model and emphasize an intuitive understanding of interesting features (as beam geometry, positioning of permanent magnets, particle radius,particle velocity,radius of curvature of particle inside cusped magnetic field)

  11. Double cusp encounter by Cluster: double cusp or motion of the cusp?

    Czech Academy of Sciences Publication Activity Database

    Escoubet, C. P.; Berchem, J.; Trattner, K. J.; Pitout, F.; Richard, R.; Taylor, M. G. G. T.; Souček, Jan; Grison, Benjamin; Laakso, H.; Masson, A.; Dunlop, M.; Dandouras, I.; Reme, H.; Fazakerley, A.; Daly, P.

    2013-01-01

    Roč. 31, č. 4 (2013), s. 713-723. ISSN 0992-7689 R&D Projects: GA ČR(CZ) GPP209/11/P848 Institutional support: RVO:68378289 Keywords : Magnetospheric physics * Magnetopause * cusp * boundary layers Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.676, year: 2013 http://www.ann-geophys.net/31/713/2013/

  12. Cassini observations of Saturn's southern polar cusp

    OpenAIRE

    Arridge, Christopher Stephen; Jasinski, J. M.; Achilleos, Nicholas; Bogdanova, Y. V.; E. J. Bunce; Cowley, S. W. H; A. N. Fazakerley; Khurana, K K; Lamy, Laurent; J. S. Leisner; Roussos, E; Russell, C. T.; Zarka, P.; Coates, A. J.; Dougherty, M. K.

    2016-01-01

    The magnetospheric cusps are important sites of the coupling of a magnetosphere with the solar wind. The combination of both ground- and space-based observations at Earth have enabled considerable progress to be made in understanding the terrestrial cusp and its role in the coupling of the magnetosphere to the solar wind via the polar magnetosphere. Voyager 2 fully explored Neptune’s cusp in 1989 but highly inclined orbits of the Cassini spacecraft at Saturn present the most recent opportunit...

  13. Air entrainment through free-surface cusps

    CERN Document Server

    Eggers, J

    2000-01-01

    In many industrial processes, such as pouring a liquid or coating a rotating cylinder, air bubbles are entrapped inside the liquid. We propose a novel mechanism for this phenomenon, based on the instability of cusp singularities that generically form on free surfaces. The air being drawn into the narrow space inside the cusp destroys its stationary shape when the walls of the cusp come too close. Instead, a sheet emanates from the cusp's tip, through which air is entrained. Our analytical theory of this instability is confirmed by experimental observation and quantitative comparison with numerical simulations of the flow equations.

  14. Use of short roll C-arm computed tomography and fully automated 3D analysis tools to guide transcatheter aortic valve replacement.

    Science.gov (United States)

    Kim, Michael S; Bracken, John; Eshuis, Peter; Chen, S Y James; Fullerton, David; Cleveland, Joseph; Messenger, John C; Carroll, John D

    2016-07-01

    Determination of the coplanar view is a critical component of transcatheter aortic valve replacement (TAVR). The safety and accuracy of a novel reduced angular range C-arm computed tomography (CACT) approach coupled with a fully automated 3D analysis tool package to predict the coplanar view in TAVR was evaluated. Fifty-seven patients with severe symptomatic aortic stenosis deemed prohibitive-risk for surgery and who underwent TAVR were enrolled. Patients were randomized 2:1 to CACT vs. angiography (control) in estimating the coplanar view. These approaches to determine the coplanar view were compared quantitatively. Radiation doses needed to determine the coplanar view were recorded for both the CACT and control patients. Use of CACT offered good agreement with the actual angiographic view utilized during TAVR in 34 out of 41 cases in which a CACT scan was performed (83 %). For these 34 cases, the mean angular magnitude difference, taking into account both oblique and cranial/caudal angulation, was 1.3° ± 0.4°, while the maximum difference was 7.3°. There were no significant differences in the mean total radiation dose delivered to patients between the CACT and control groups as measured by either dose area product (207.8 ± 15.2 Gy cm(2) vs. 186.1 ± 25.3 Gy cm(2), P = 0.47) or air kerma (1287.6 ± 117.7 mGy vs. 1098.9 ± 143.8 mGy, P = 0.32). Use of reduced-angular range CACT coupled with fully automated 3D analysis tools is a safe, practical, and feasible method by which to determine the optimal angiographic deployment view for guiding TAVR procedures. PMID:27091735

  15. Cassini observations of Saturn's southern polar cusp

    Science.gov (United States)

    Arridge, C. S.; Jasinski, J. M.; Achilleos, N.; Bogdanova, Y. V.; Bunce, E. J.; Cowley, S. W. H.; Fazakerley, A. N.; Khurana, K. K.; Lamy, L.; Leisner, J. S.; Roussos, E.; Russell, C. T.; Zarka, P.; Coates, A. J.; Dougherty, M. K.; Jones, G. H.; Krimigis, S. M.; Krupp, N.

    2016-04-01

    The magnetospheric cusps are important sites of the coupling of a magnetosphere with the solar wind. The combination of both ground- and space-based observations at Earth has enabled considerable progress to be made in understanding the terrestrial cusp and its role in the coupling of the magnetosphere to the solar wind via the polar magnetosphere. Voyager 2 fully explored Neptune's cusp in 1989, but highly inclined orbits of the Cassini spacecraft at Saturn present the most recent opportunity to repeatedly study the polar magnetosphere of a rapidly rotating planet. In this paper we discuss observations made by Cassini during two passes through Saturn's southern polar magnetosphere. Our main findings are that (i) Cassini directly encounters the southern polar cusp with evidence for the entry of magnetosheath plasma into the cusp via magnetopause reconnection, (ii) magnetopause reconnection and entry of plasma into the cusp can occur over a range of solar wind conditions, and (iii) double cusp morphologies are consistent with the position of the cusp oscillating in phase with Saturn's global magnetospheric periodicities.

  16. Sudden death in a youth. A case of quadricuspid aortic valve with isolation of origin of left coronary artery.

    OpenAIRE

    Kurosawa, H.; Wagenaar, S. S.; Becker, A E

    1981-01-01

    A youth of 16 years of age died suddenly and quite unexpectedly while walking to school. The necropsy disclosed a quadricuspid aortic valve with complete isolation of the left coronary artery by an adherent aortic valve cusp. The left ventricular myocardium showed subendocardial contraction band necrosis suggesting that critical ischaemia had triggered a state of hypercontraction, in keeping with ventricular fibrillation as the immediate cause of death. The site of the anomaly in the aortic r...

  17. Double Cusp Observed By The Cluster Spacecraft

    Science.gov (United States)

    Escoubet, C. P.; Bosqued, J. M.; Berchem, J.; Anderson, P. C.; Fehringer, M.; Laakso, H.; Reme, H.

    The polar cusp is characterised by a direct entry of solar wind plasma into the magne- tosphere. Depending on the orientation of the interplanetary magnetic field (IMF), Bz positive or negative, the precipitation of the ions in the cusp presents a dispersion in energy directed poleward or equatorward. In addition the polar cusp moves in latitude according to the IMF, from about 75 deg. ILAT for Bz negative to about 82 deg. ILAT for Bz positive. The Cluster spacecraft are crossing the mid-altitude polar cusp, in a "string of pearl" configuration, and are therefore the ideal tool to study the motion and evolution of the cusp on time scale of a few minutes up to 45 min. On 30 August 2001, the four Cluster spacecraft crossed the mid-altitude polar cusp (4-6 Re) around 12.5 H local time with SC4 entering the cusp at 1532 UT, SC2 following 1.5 min later, SC1, 3 min later and finally SC3, 45 min later. SC4 and SC1 observed a typical poleward dispersion associated with Bz negative. SC3 observed first the same disper- sion starting at about 74 deg. ILAT, however at 81 deg. ILAT a second dispersion was observed. The IMF was southward during the dispersion and became slightly positive during the second dispersion. Two hypothesis can be proposed, a fast motion of the cusp poleward during the SC3 crossing or a double injection in the cusp. Preliminary analysis of DMSP satellites, although not exactly in the same sector, indicates that the cusp moved poleward around that time. Cluster observations will be compared with the results from a global MHD simulation model to investigate the geometry of the reconnection between the IMF and the Earth magnetic field.

  18. [Pannus Formation Two Years after Bioprosthetic Aortic Valve Implantation;Report of a Case].

    Science.gov (United States)

    Ono, Kimiyo; Kuroda, Hiroaki

    2015-08-01

    We report a case of early deterioration of the bioprosthetic aortic valve 23 months postoperatively. A 77-year-old man who had undergone aortic valve replacement with a 23-mm Epic valve( St. Jude Medical [SJM])presented to us after a syncopal episode. Echocardiography revealed severe aortic stenosis, and redo aortic valve replacement with a 21-mm SJM mechanical valve was performed. All 3 cusps of the tissue valve were thickened by fibrous pannus overgrowth. Neither calcification nor invasion of inflammatory cells was observed. The cause of pannus formation at such an early stage after implantation remains unknown. PMID:26329714

  19. Aortic stenting.

    Science.gov (United States)

    Droc, Ionel; Calinescu, Francisca Blanca; Droc, Gabriela; Blaj, Catalin; Dammrau, Rolf

    2015-01-01

    The approach to aortic pathology is nowadays more and more endovascular at both thoracic and abdominal levels. Thoracic stenting has gained worldwide acceptance as first intention to treat pathologies of the descending thoracic aorta. Indications have been extended to aortic arch aneurysms and also to diseases of the ascending aorta. The current devices in use for thoracic endovascular repair (TEVAR) are Medtronic Valiant, Gore TAG, Cook Tx2 and Jotec. The choice of the endograft depends on the thoracic aortic pathology and the anatomical suitability. The technological evolution of the abdominal aortic endografts was very rapid, arriving now at the fourth generation. We report the results of 55 elective cases of endovascular abdominal aortic repair (EVAR) performed in two vascular surgical centers in Romania and Germany. The prostheses used were 16 E-vita Abdominal XT, 12 Excluder, eight Talent, seven PowerLink, three Endurant and nine custom-made, fenestrated or branched from Jotec. The mean follow-up was 18 months with CT-scan, duplex ultrasound and contrast-enhanced ultrasound. The mortality was 2%. EVAR tends to become the gold standard for abdominal aortic aneurysm repair. Technological development of the devices with lowest profile introduction systems will permit to extend the anatomical indications to new frontiers. PMID:26200430

  20. Reinterpreting several narrow `resonances' as threshold cusps

    CERN Document Server

    Bugg, D V

    2004-01-01

    The threshold pbar-p peak in BES data for J/\\Psi to gamma-pbar-p may be fitted as a cusp. It arises from the well known threshold peak in pbar-p elastic scattering due to annihilation. Several similar examples are discussed. The PS185 data for pbar-p to Lambdabar-Lambda require an almost identical cusp at the Lambdabar-Lambda threshold. There is also a cusp at the Sigma-N threshold in Kminus-d to piminus-Lambda-p. Similar cusps are likely to arise at thresholds for all 2-body de-excitation processes, providing the interaction is attractive; likely examples are Lambda-pbar, Sigma-pbar, and Kbar-Lambda. The narrow peak observed by Belle at 3872 MeV in piplus-piminus-J/Psi may be a 1++ cusp due to the Dbar-D* threshold. The narrow Xi*(1862) observed by NA49 may be due to a threshold cusp in Sigma(1385)-Kbar coupled to Xi-pi and Sigma-Kbar. The relation of cusps to known resonances such as fo(980) is discussed.

  1. The study of electromagnetic cusp solitons

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Deepa; Das, Amita; Kaw, Predhiman; Tiwari, Sanat Kumar [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2015-01-15

    The formation of a cusp structure in the envelope of electromagnetic solitons for electron-ion plasma at the ion wave breaking point has been shown by Farina and Bulanov [Phys. Rev. Lett. 86, 5289 (2001)]. The analytical form of the cusp structure has been obtained here. The analytical form of the cusp is shown to compare well with the exact numerically obtained solutions. Such cusp solitons occurring at the ion wave breaking point may have relevance to ion acceleration mechanism. In an effort towards studying the dynamical stability of such structures, the time evolution studies have been carried out which show that the structure survives for several plasma periods. However, ultimately it breaks apart due to the instability associated with the forward Raman scattering.

  2. Magion-4 High-Altitude Cusp Study

    Czech Academy of Sciences Publication Activity Database

    Merka, J.; Šafránková, J.; Němeček, Z.; Šimůnek, Jiří

    2005-01-01

    Roč. 26, č. 1-3 (2005), s. 57-69. ISSN 0169-3298 R&D Projects: GA ČR(CZ) GA205/02/0947 Institutional research plan: CEZ:AV0Z30420517 Keywords : cusp-like plasma * dipole tilt angle * high - altitude cusp * magnetopause * magnetopause * reconnection Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.975, year: 2005

  3. The Energetics of Cusp Destruction

    CERN Document Server

    Maxwell, Aaron J; Couchman, H M P

    2015-01-01

    We present a new analytic estimate for the energy required to create a constant density core within a dark matter halo. Our new estimate, based on more realistic assumptions, leads to a required energy that is orders of magnitude lower than is claimed in earlier work. We define a core size based on the logarithmic slope of the dark matter density profile so that it is insensitive to the functional form used to fit observed data. The energy required to form a core depends sensitively on the radial scale over which dark matter within the cusp is redistributed within the halo. Simulations indicate that within a region of comparable size to the active star forming regions of the central galaxy that inhabits the halo, dark matter particles have their orbits radially increased by a factor of 2--3 during core formation. Thus the inner properties of the dark matter halo, such as halo concentration, and final core size, set the energy requirements. As a result, the energy cost increases slowly with halo mass as M$_{\\r...

  4. Dependency of the Cusp Density Anomaly on the Variability of Forcing Inside and Outside the Cusp

    Science.gov (United States)

    Brinkman, D. G.; Walterscheid, R. L.; Clemmons, J. H.

    2014-12-01

    The Earth's magnetospheric cusp provides direct access of energetic particles to the thermosphere. These particles produce ionization and kinetic (particle) heating of the atmosphere. The increased ionization coupled with enhanced electric fields in the cusp produces increased Joule heating and ion drag forcing. These energy inputs largely determine the neutral density structure in the cusp region. Measurements by the CHAMP satellite (460-390- km altitude) have shown a region of strong enhanced density attributed to the combination of cusp particle and Joule heating. The Streak mission (325-123 km), on the other hand, observed a relative depletion in density in the cusp. While particle precipitation in the cusp is comparatively well constrained, the characteristics of the steady and fluctuating components of the electric field in the cusp are poorly constrained. Also, the significance of harder particle precipitation in areas adjacent to the cusp in particular at lower altitudes has not been addressed as it relates to the cusp density anomaly. We address the response of the cusp region to a range electrodynamical forcing with our high resolution two-dimensional time-dependent nonhydrostatic nonlinear dynamical model. We take advantage of our model's high resolution and focus on a more typical cusp width of 2 degrees in latitude. Earlier simulations have also shown a significant contribution from soft particle precipitation. We simulate the atmospheric response to a range of realizable magnitudes of the fluctuating and steady components of the electric field to examine the dependence of the magnitude of the cusp density anomaly on a large range of observed characteristics of the electrodynamical forcing and examine, in particular, the importance of particle heating relative to Joule heating. In addition we investigate the role of harder particle precipitation in areas adjacent to the cusp in determining the lower altitude cusp density and wind structure. We compare

  5. Hemispherical asymmetry in cusp precipitation near solstices

    International Nuclear Information System (INIS)

    A statistical comparison of the peak flux in electron and ion polar cusp precipitation in the summer and winter hemispheres as observed by the low-altitude DMSP F7 satellite is performed. Data studied encompass four consecutive solstices from December 1983 to June 1985, comprising 77 days of data with a total of 292 individual cusp passes. On each day, observations were restricted to those few hours UT in which the interhemispherical MLT variation of DMSP F7 was smallest. After the remaining local time effect was averaged out, the summer hemisphere ion (electron) precipitating energy flux was larger, on the average, by 61 +- 11% (51 +- 5%) than that in the winter hemisphere. However, the average particle energy was always lower for both species in the summer hemisphere. These effects generally hold true for northward as well as southward interplanetary magnetic fields (IMF). It is argued that the observed asymmetry is very hard to explain if the most intense part of the cusp lies on closed field lines, but it is shown that the standard open field line model of the cusp virtually requires the observed differences to occur. The present results thus suggest that the most intense portion of the cusp lies on open field lines even for northward IMF. copyright American Geophysical Union 1988

  6. Cusp geometry of fibered 3-manifolds

    CERN Document Server

    Futer, David

    2011-01-01

    Let F be a surface and suppose that \\phi: F -> F is a pseudo-Anosov homeomorphism fixing a puncture p of F. The mapping torus M = M_\\phi\\ is hyperbolic and contains a maximal cusp C about the puncture p. We show that the area and height of the cusp torus bounding C are equal, up to explicit multiplicative error, to the stable translation distance of \\phi\\ acting on the arc complex A(F,p). Our proofs rely on elementary facts about the hyperbolic geometry of pleated surfaces. In particular, we do not use any deep results in Teichmueller theory, Kleinian group theory, or the coarse geometry of A(F,p). A similar result holds for quasi-Fuchsian manifolds N = (F x R). In that setting, we prove a combinatorial estimate on the area and height of the cusp annulus in the convex core of N and give explicit multiplicative and additive errors.

  7. Cusps, self-organization, and absorbing states.

    Science.gov (United States)

    Bonachela, Juan A; Alava, Mikko; Muñoz, Miguel A

    2009-05-01

    Elastic interfaces embedded in (quenched) random media exhibit metastability and stick-slip dynamics. These nontrivial dynamical features have been shown to be associated with cusp singularities of the coarse-grained disorder correlator. Here we show that annealed systems with many absorbing states and a conservation law but no quenched disorder exhibit identical cusps. On the other hand, similar nonconserved systems in the directed percolation class are also shown to exhibit cusps but of a different type. These results are obtained both by a recent method to explicitly measure disorder correlators and by defining an alternative new protocol inspired by self-organized criticality, which opens the door to easily accessible experimental realizations. PMID:19518401

  8. Atomic nitrogen densities near the polar cusp

    Science.gov (United States)

    Engebretson, M. J.; Nelson, J. T.

    1986-01-01

    The neutral atmospheric composition spectrometer on board the Dynamics Explorer 2 spacecraft sampled several major and minor thermospheric gases including atomic nitrogen. A selection of passes over the polar cusp that provide a quantitative measure of N densities in this region and provide evidence of localized density increases due to soft particle precipitation is presented. Increases in N densities are frequently observed but are smaller than accompanying increases in N2 densities. The observations support earlier studies suggesting that N densities increase more rapidly than O densities during periods of high solar EUV flux and N densities are larger in the summer hemisphere than in the winter hemisphere. A series of passes in February 1983, late in the lifetime of DE 2, indicated N densities at 200 km altitude were a factor of 2 larger near the southern cusp than near the northern cusp.

  9. The ASACUSA CUSP: an antihydrogen experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, N., E-mail: kuroda@phys.c.u-tokyo.ac.jp [University of Tokyo, Graduate School of Arts and Sciences (Japan); Ulmer, S. [RIKEN, Ulmer Initiative Research Unit (Japan); Murtagh, D. J.; Gorp, S. Van [RIKEN, Atomic Physics Laboratory (Japan); Nagata, Y. [Tokyo University of Agriculture and Technology, Department of Applied Physics (Japan); Diermaier, M. [Boltzmangasse 3, Stefan Meyer Institut für Subatomare Physik (Austria); Federmann, S. [CERN (Switzerland); Leali, M. [Università di Brescia & Instituto Nazionale di Fisica Nucleare, Dipartimento di Chimica e Fisica per l’Ingegneria e per i Materiali (Italy); Malbrunot, C. [CERN (Switzerland); Mascagna, V. [Università di Brescia & Instituto Nazionale di Fisica Nucleare, Dipartimento di Chimica e Fisica per l’Ingegneria e per i Materiali (Italy); Massiczek, O. [Boltzmangasse 3, Stefan Meyer Institut für Subatomare Physik (Austria); Michishio, K. [Tokyo University of Science, Department of Physics (Japan); Mizutani, T. [University of Tokyo, Graduate School of Arts and Sciences (Japan); Mohri, A. [Kyoto University, Graduate School of Human and Environmental Sciences (Japan); Nagahama, H.; Ohtsuka, M. [University of Tokyo, Graduate School of Arts and Sciences (Japan); Radics, B. [RIKEN, Atomic Physics Laboratory (Japan); Sakurai, S. [Hiroshima University, Graduate School of Advanced Science of Matter (Japan); Sauerzopf, C.; Suzuki, K. [Boltzmangasse 3, Stefan Meyer Institut für Subatomare Physik (Austria); and others

    2015-11-15

    In order to test CPT symmetry between antihydrogen and its counterpart hydrogen, the ASACUSA collaboration plans to perform high precision microwave spectroscopy of ground-state hyperfine splitting of antihydrogen atom in-flight. We have developed an apparatus (“cusp trap”) which consists of a superconducting anti-Helmholtz coil and multiple ring electrodes. For the preparation of slow antiprotons and positrons, Penning-Malmberg type traps were utilized. The spectrometer line was positioned downstream of the cusp trap. At the end of the beamline, an antihydrogen beam detector was located, which comprises an inorganic Bismuth Germanium Oxide (BGO) single-crystal scintillator housed in a vacuum duct and surrounding plastic scintillators. A significant fraction of antihydrogen atoms flowing out the cusp trap were detected.

  10. Reproducibility of aortic annulus measurements by computed tomography

    International Nuclear Information System (INIS)

    To evaluate a systematic approach for measurement of aortic annulus dimensions by cardiac computed tomography. CT data sets of 64 patients were evaluated. An oblique cross-section aligned with the aortic root was created by systematically identifying the caudal insertion points of the three aortic cusps and sequentially aligning them in a double oblique plane. Aortic annulus dimensions, distances of coronary ostia and a suitable fluoroscopic projection angle were independently determined by two observers. Interobserver intraclass correlation coefficients (ICC) for aortic annulus diameters were excellent (ICC 0.89-0.93). Agreement for prosthesis size selection was excellent (k = 0.86 for mean, k = 0.84 for area-derived and k = 0.91 for circumference-derived diameter). Mean distances of the left/right coronary ostium were 13.4 ± 2.4/14.4 ± 2.8 mm for observer 1 and 13.2 ± 2.7/13.5 ± 3.2 mm for observer 2 (p = 0.30 and p = 0.0001, respectively; ICC 0.76/0.77 for left/right coronary artery). A difference of less than 10 for fluoroscopic projection angle was achieved in 84.3 % of patients. A systematic approach to generate a double oblique imaging plane exactly aligned with the aortic annulus demonstrates high interobserver and intraobserver agreements for derived measurements which are not influenced by aortic root calcification. (orig.)

  11. Reproducibility of aortic annulus measurements by computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schuhbaeck, Annika; Achenbach, Stephan [University of Erlangen, Department of Cardiology, Erlangen (Germany); University of Giessen, Department of Cardiology, Giessen (Germany); Pflederer, Tobias; Marwan, Mohamed; Schmid, Jasmin; Arnold, Martin [University of Erlangen, Department of Cardiology, Erlangen (Germany); Nef, Holger; Rixe, Johannes; Hecker, Franziska [University of Giessen, Department of Cardiology, Giessen (Germany); Schneider, Christian [University of Giessen, Department of Radiology, Giessen (Germany); Lell, Michael; Uder, Michael [University of Erlangen, Department of Radiology, Erlangen (Germany)

    2014-08-15

    To evaluate a systematic approach for measurement of aortic annulus dimensions by cardiac computed tomography. CT data sets of 64 patients were evaluated. An oblique cross-section aligned with the aortic root was created by systematically identifying the caudal insertion points of the three aortic cusps and sequentially aligning them in a double oblique plane. Aortic annulus dimensions, distances of coronary ostia and a suitable fluoroscopic projection angle were independently determined by two observers. Interobserver intraclass correlation coefficients (ICC) for aortic annulus diameters were excellent (ICC 0.89-0.93). Agreement for prosthesis size selection was excellent (k = 0.86 for mean, k = 0.84 for area-derived and k = 0.91 for circumference-derived diameter). Mean distances of the left/right coronary ostium were 13.4 ± 2.4/14.4 ± 2.8 mm for observer 1 and 13.2 ± 2.7/13.5 ± 3.2 mm for observer 2 (p = 0.30 and p = 0.0001, respectively; ICC 0.76/0.77 for left/right coronary artery). A difference of less than 10 for fluoroscopic projection angle was achieved in 84.3 % of patients. A systematic approach to generate a double oblique imaging plane exactly aligned with the aortic annulus demonstrates high interobserver and intraobserver agreements for derived measurements which are not influenced by aortic root calcification. (orig.)

  12. Talon Cusp in Maxillary Permanent Incisor Teeth: Case Report

    OpenAIRE

    YAPAR, Arş. Gör. Dt. Merve İŞCAN; İLDAY, Yrd. Doç. Dr. Nurcan ÖZAKAR; ÇAĞLAYAN, Yrd. Doç. Dr. Fatma; NilgünSEVEN, Prof. Dr.

    2013-01-01

    Talon cusp is an uncommon developmental dental anomaly referring to an accessory cusp projecting from the cingulum area, or cemento-enamel junction of maxillary or mandibular anterior teeth, in both the primary and permanent dentition. The etiology of talon cusp is not well understood , but appears to have both genetic and environmental components. Permanent dentition have been involved three times more often than the primary dentition. This anomalous cusp may or may not cantain pulpal tissue...

  13. A facial talon cusp on maxillary permanent central incisors

    Directory of Open Access Journals (Sweden)

    Suneelkumar Chinni

    2012-01-01

    Full Text Available Talon cusp is a dental anomaly that occurs as an accessory cusp like structure, from the cingulum of maxillary and mandibular anterior teeth. Lingual location is usually considered pathognomic. This case report discuss about the unusual appearance of talon cusp on the facial surface of the maxillary left permanent central incisor and a mild talon cusp on the facial surface of the maxillary right permanent central incisor.

  14. High Energy Electron Confinement in a Magnetic Cusp Configuration

    OpenAIRE

    Park, Jaeyoung; Krall, Nicholas A.; Sieck, Paul E.; Offermann, Dustin T.; Skillicorn, Michael; Sanchez, Andrew; Davis, Kevin; Alderson, Eric; Lapenta, Giovanni

    2014-01-01

    We report experimental results validating the concept that plasma confinement is enhanced in a magnetic cusp configuration when beta (plasma pressure/magnetic field pressure) is order of unity. This enhancement is required for a fusion power reactor based on cusp confinement to be feasible. The magnetic cusp configuration possesses a critical advantage: the plasma is stable to large scale perturbations. However, early work indicated that plasma loss rates in a reactor based on a cusp configur...

  15. A facial talon cusp on maxillary permanent central incisors

    OpenAIRE

    Suneelkumar Chinni; Mayuri Nanneboyina; Anilkumar Ramachandran; Hanuman Chalapathikumar

    2012-01-01

    Talon cusp is a dental anomaly that occurs as an accessory cusp like structure, from the cingulum of maxillary and mandibular anterior teeth. Lingual location is usually considered pathognomic. This case report discuss about the unusual appearance of talon cusp on the facial surface of the maxillary left permanent central incisor and a mild talon cusp on the facial surface of the maxillary right permanent central incisor.

  16. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gold or stainless steel cusp. 872.3350 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3350 Gold or stainless steel cusp. (a) Identification. A gold or stainless steel cusp is a prefabricated device made of austenitic alloys or...

  17. The Magnetospheric Cusps Structure and Dynamics

    CERN Document Server

    Fritz, Theodore A

    2005-01-01

    This collection of papers will address the question "What is the Magnetospheric Cusp?" and what is its role in the coupling of the solar wind to the magnetosphere as well as its role in the processes of particle transport and energization within the magnetosphere. The cusps have traditionally been described as narrow funnel-shaped regions that provide a focus of the Chapman-Ferraro currents that flow on the magnetopause, a boundary between the cavity dominated by the geomagnetic field (i.e., the magnetosphere) and the external region of the interplanetary medium. Measurements from a number of recent satellite programs have shown that the cusp is not confined to a narrow region near local noon but appears to encompass a large portion of the dayside high-latitude magnetosphere and it appears that the cusp is a major source region for the production of energetic charged particles for the magnetosphere. Audience: This book will be of interest to space science research organizations in governments and industries, ...

  18. ANALYSIS OF TRANSONIC FLOW PAST CUSPED AIRFOILS

    Directory of Open Access Journals (Sweden)

    Jiří Stodůlka

    2015-06-01

    Full Text Available Transonic flow past two cusped airfoils is numerically solved and achieved results are analyzed by means of flow behavior and oblique shocks formation.Regions around sharp trailing edges are studied in detail and parameters of shock waves are solved and compared using classical shock polar approach and verified by reduction parameters for symmetric configurations.

  19. Cusp relation for the Pauli potential

    Science.gov (United States)

    Levämäki, H.; Nagy, Á.; Kokko, K.; Vitos, L.

    2014-12-01

    In orbital-free density functional theory, only a Schrödinger-like equation has to be solved for the square root of the electron density. In this equation, however, there is an extra potential in addition to the Kohn-Sham potential, the so-called Pauli potential. Cusp relations are now presented for this Pauli potential for spherically symmetric systems.

  20. Turbulence in a cusp Q device

    DEFF Research Database (Denmark)

    D'Angelo, N.; Pécseli, Hans; Petersen, P. I.

    1974-01-01

    Spectral measurements are reported of plasma turbulence in the Cs plasma of a Q device, modified to a magnetic cusp geometry. The excitation mechanism for the fluctuations appears to be the centrifugal instability discussed by Chen. A transition from an f−5 to an f−3 power spectrum is observed as...

  1. Aortic valve bypass

    DEFF Research Database (Denmark)

    Lund, Jens T; Jensen, Maiken Brit; Arendrup, Henrik; Ihlemann, Nikolaj

    2013-01-01

    In aortic valve bypass (AVB) a valve-containing conduit is connecting the apex of the left ventricle to the descending aorta. Candidates are patients with symptomatic aortic valve stenosis rejected for conventional aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI...

  2. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... the primary reason that we end up offering patients aortic valve surgery in our community. Aortic stenosis ... a picture of the aortic valve from a patient who had a very diseased aortic valve. And ...

  3. Talon Cusp Type I: Restorative Management

    Directory of Open Access Journals (Sweden)

    Rafael Alberto dos Santos Maia

    2015-01-01

    Full Text Available The teeth are formed during intrauterine life (i.e., gestation during the odontogenesis stage. During this period, the teeth move until they enter the oral cavity. This course covers various stages of dental development, namely, initiation, proliferation, histodifferentiation, morphodifferentiation, and apposition. The talon cusp is an anomaly that occurs during morphodifferentiation, and this anomaly may have numerous adverse clinical effects on oral health. The objective of this study was to report a case of “Talon Cusp Type I” and to discuss diagnostic methods, treatment options for this anomaly, and the importance of knowledge of this morphological change among dental professionals so that it is not confused with other morphological changes; such knowledge is required to avoid unnecessary surgical procedures, to perform treatments that prevent caries and malocclusions as well as enhancing aesthetics, and to improve the oral health and quality of life of the patient.

  4. Talon Cusp Type I: Restorative Management

    OpenAIRE

    Rafael Alberto dos Santos Maia; Wanessa Christine de Souza-Zaroni; Raul Sampaio Mei; Fernando Lamers

    2015-01-01

    The teeth are formed during intrauterine life (i.e., gestation) during the odontogenesis stage. During this period, the teeth move until they enter the oral cavity. This course covers various stages of dental development, namely, initiation, proliferation, histodifferentiation, morphodifferentiation, and apposition. The talon cusp is an anomaly that occurs during morphodifferentiation, and this anomaly may have numerous adverse clinical effects on oral health. The objective of this study was ...

  5. Hollow vortices and wakes past Chaplygin cusps

    OpenAIRE

    Lasagna, Davide; Zannetti, Luca

    2013-01-01

    By using analytic tools for 2D rotational inviscid flow, the stagnation points of Pocklington hollow vortices are replaced by Chaplygin cusps, that is, by regions of fluid at rest. By solidifying the bounding free streamlines, solid bodies are obtained along whose walls adverse pressure gradients are avoided. These results are relevant to the theory and practice of control of separated flow at high Reynolds number. Examples are presented pertinent to single bodies and cascade of bodies which ...

  6. Histopathological study of congenital aortic valve malformations in 32 children

    Institute of Scientific and Technical Information of China (English)

    HUANG Ping; WANG Hongwei; LI Yanping; CHENG Peixuan; LIU Qingjun; ZHANG Zhenlu; LIU Jianying

    2007-01-01

    The histopathological characteristics of congenital aortic valve malformations in children were investigated.All the native surgically excised aortic valves from 32 pediatric patients suffering from symptomatic aortic valve dysfunction due to congenital aortic valve malformations between January 2003 and December 2005 were studied macroscopically and microscopically.The patients' medical records were reviewed and the clinical information was extracted.The diagnosis was made by the clinical presentation,preoperative echocardiography,intraoperative examination,and postoperative histopathological study,excluding rheumatic ot degenerative aortic valve diseases,infective endocarditis and primary connective tissue disorders,e.g.Marfan syndrome.Among 32 children with congenital aortic valve malformations,the age was ranged from six to 18 years,with a mean of 14.9 years,and there were 27 boys and five girls (male:female = 5.4:1).There were five cases of aortic stenosis (AS,15.62%),25 cases of aortic insufficiency (AI,78.13 %)and two cases of AS-AI (6.25%),without other valve diseases.Twenty cases still had other congenital heart diseases:ventricular septal defect (19 cases),patent ductus arteriosus (two cases),double-chambered right ventricle (one case),aneurysm of the right anterior aortic sinus of valsalva (three cases).Histopathological examination indicated that the cusps became thickening with unequal size,irregular shape (coiling and prolapse edge),enhanced hardness,and partly calcification.Microscopic investigation revealed the unsharp structure of valve tissue,fibrosis,myxomatous,reduced collagen fiber,rupture of elastic fibers,different degrees of infiltration of inflammatory cells,secondary calcareous and lipid deposit,and secondary fibrosis.Congenital aortic valve malformations in children involve males more than females,mostly associated with other congenital heart diseases.Aortic insufficiency is more common in children with congenital aortic valve

  7. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... to become you to our live webcast. Today we’re going to repair an abdominal aortic aneurysm ... and together as a team of multidisciplinary physicians, we’re going to repair an abdominal aortic aneurysm ...

  8. Aortic Aneurysm Statistics

    Science.gov (United States)

    ... connective tissue disorders, such as Marfan syndrome and Ehlers-Danlos syndrome, get thoracic aortic aneurysms. Signs and symptoms of thoracic aortic aneurysm can include Sharp, sudden pain in the chest or upper back. Shortness of ...

  9. Non-syndromic multiple talon cusps in siblings

    OpenAIRE

    Gaurav Sharma; Anudeep R Mutneja; Archna Nagpal; Puneet Mutneja

    2014-01-01

    Talon′s cusp is an anomalous structure that projects palatally from the cingulum areas of maxillary or mandibular anterior teeth. This dental anomaly may pose several pathological, functional and esthetic problems. Talon cusps usually affect a single tooth, but may rarely affect an entire sextant. Such multiple talon cusps may not always occur in association with a syndrome. Furthermore, they may exhibit a genetic pattern of inheritance. This article emphasizes rare occurrence of such nonsynd...

  10. High resolution modeling of the cusp density anomaly

    Science.gov (United States)

    Brinkman, D. G.; Walterscheid, R. L.; Clemmons, J. H.

    2013-12-01

    The Earth's magnetospheric cusp provides direct access of energetic particles to the thermosphere causing an ionization anomaly. The energy from these particles along with Joule heating, and ion drag forcing play a direct role in determining the neutral density structure in the cusp region. Measurements by the CHAMP (390-460 km altitudes) have shown a region of strong enhanced density attributed to upwelling caused by the combination of particle and Joule heating. The Streak mission (325-123 km) observed a relative depletion in density in the cusp which was attributed to soft particle precipitation not being adequate to cause upwelling at the lower altitudes sampled by Streak and relatively harder precipitation in adjacent areas. Recent attempts to model the cusp density anomaly with Global Circulation Models (GCM) have focused on extreme cases with forcing extending over latitudinal cusp widths of 4 degrees or more which are at the extreme upper end of the observations. Even at one degree latitudinal resolution the cusp features are marginally captured. More typical cusps widths of 1-2 degrees in latitude require finer resolution to resolve. We use a high-resolution numerical model of the thermosphere to simulate the atmospheric response to the relevant forcing by realistically specifying the particle heating, Joule heating, and ion drag forcing to examine the dependence of the magnitude of the cusp density anomaly and the corresponding wind structure on the characteristics of the forcing in the cusp. We ran simulations for cusp widths of 4 and 2 degrees latitude using a model resolution of 20 km. We found that reducing the cusp width by half reduced the density response in the cusp by half, but that the wind response was only slightly decreased. We compare the model results to CHAMP and Streak observations and assess the relative contributions of these mechanisms in explaining the distinctive features of the observations. Acknowledgements: This research was

  11. Kinematic Cusps with Two Missing Particles II: Cascade Decay Topology

    OpenAIRE

    Han, Tao; Kim, Ian-Woo; Song, Jeonghyeon

    2012-01-01

    Three-step cascade decays into two invisible particles and two visible particles via two intermediate on-shell particles develop cusped peak structures in several kinematic distributions. We study the basic properties of the cusps and endpoints in various distributions and demonstrate that the masses of the missing particles and the intermediate particles can be determined by the cusp and endpoint positions. Effects from realistic considerations such as finite decay widths, longitudinal boost...

  12. Overlapping cusp ion injections: An explanation invoking magnetopause reconnection

    OpenAIRE

    Lockwood, Mike

    1995-01-01

    An explanation of overlapping cusp ion injections is presented using the pulsating cusp model of the effects of magnetopause reconnection. It is shown that two populations of cusp ions, covering separated energy ranges, can be seen simultaneously by low- or mid-altitude satellites because of the combined effect of the acceleration and the straightening of newly-opened field lines as they evolve away from the reconnection site. Observations of such signatures, recently reported in data from th...

  13. Aortic growth rates in chronic aortic dissection

    International Nuclear Information System (INIS)

    Aim: To determine and compare rates of descending aortic enlargement and complications in chronic aortic dissection with and without a proximal aortic graft. Methods and materials: Fifty-two patients with dissection involving the descending aorta and who had undergone at least two computed tomography (CT) examinations at our institution between November, 1993 and February, 2004 were identified, including 24 non-operated patients (four type A, 20 type B) and 28 operated patients (type A). CT examinations per patient ranged from two to 10, and follow-up ranged from 1-123 months (mean 49 months, median 38.5 months). On each CT image, the aortic short axis (SA), false lumen (FL), and true lumen (TL) diameters were measured at the longitudinal midpoint of the dissection and at the point of maximum aortic diameter. Complications were tabulated, including aortic rupture and aortic enlargement requiring surgery. Results: For non-operated patients, the midpoint and maximum point SA, TL, and FL diameters increased significantly over time. For operated patients, the midpoint and maximum point SA and FL diameters increased significantly over time. In both groups, aortic enlargement was predominantly due to FL expansion. Diameter increases in non-operated patients were significantly larger than those in operated patients. The rate of change in aortic diameter was constant, regardless of aortic size. Four non-operated and six operated patients developed aortic complications. Conclusions: In patients with a dissection involving the descending thoracic aorta, the FL increased in diameter over time, at a constant rate, and to a greater degree in non-operated patients (mostly type B) compared with operated patients (all type A)

  14. Non-syndromic multiple talon cusps in siblings

    Directory of Open Access Journals (Sweden)

    Gaurav Sharma

    2014-01-01

    Full Text Available Talon′s cusp is an anomalous structure that projects palatally from the cingulum areas of maxillary or mandibular anterior teeth. This dental anomaly may pose several pathological, functional and esthetic problems. Talon cusps usually affect a single tooth, but may rarely affect an entire sextant. Such multiple talon cusps may not always occur in association with a syndrome. Furthermore, they may exhibit a genetic pattern of inheritance. This article emphasizes rare occurrence of such nonsyndromic multiple talon cusps in two siblings.

  15. An echo-guided case report of rapid regression of unstable mobile thrombus aortic atheroma after aggressive statin and antiplatelet combination therapy.

    Science.gov (United States)

    Dʼaloia, Antonio; Vizzardi, Enrico; Caretta, Giorgio; Zanini, Gregoriana; Bugatti, Silvia; Curnis, Antonio; Dei Cas, Livio

    2014-01-01

    We describe a case report that documented the efficacy and safety of medical therapy in stabilizing and resolving a complex and unstable aortic atheroma after a relatively short period. The patient had a large protruding, mobile, calcified nonulcerated atheroma involving the descending aorta and was therefore treated with aggressive combination therapy with high statin dosages (atorvastatin = 80 mg) and dual antiplatelet treatment (clopidogrel = 75 mg and aspirin = 100 mg). At follow-up, the echocardiogram showed a significant regression in the atheroma volume, with no signs suggestive of ulceration on its surface with the complete mobile component resolution. PMID:23817345

  16. From cusps to cores: a stochastic model

    Science.gov (United States)

    El-Zant, Amr A.; Freundlich, Jonathan; Combes, Françoise

    2016-09-01

    The cold dark matter model of structure formation faces apparent problems on galactic scales. Several threads point to excessive halo concentration, including central densities that rise too steeply with decreasing radius. Yet, random fluctuations in the gaseous component can `heat' the centres of haloes, decreasing their densities. We present a theoretical model deriving this effect from first principles: stochastic variations in the gas density are converted into potential fluctuations that act on the dark matter; the associated force correlation function is calculated and the corresponding stochastic equation solved. Assuming a power-law spectrum of fluctuations with maximal and minimal cutoff scales, we derive the velocity dispersion imparted to the halo particles and the relevant relaxation time. We further perform numerical simulations, with fluctuations realized as a Gaussian random field, which confirm the formation of a core within a time-scale comparable to that derived analytically. Non-radial collective modes enhance the energy transport process that erases the cusp, though the parametrizations of the analytical model persist. In our model, the dominant contribution to the dynamical coupling driving the cusp-core transformation comes from the largest scale fluctuations. Yet, the efficiency of the transformation is independent of the value of the largest scale and depends weakly (linearly) on the power-law exponent; it effectively depends on two parameters: the gas mass fraction and the normalization of the power spectrum. This suggests that cusp-core transformations observed in hydrodynamic simulations of galaxy formation may be understood and parametrized in simple terms, the physical and numerical complexities of the various implementations notwithstanding.

  17. Electrodynamics of the polar cusp ionosphere

    International Nuclear Information System (INIS)

    Satellite measurements of magnetic field and ion drift components above auroral structures observed from the ground permits detailed investigations of auroral electrodynamics in the cusp ionosphere. Information on Birkeland currents, Poynting flux, height-integrated Pedersen conductivity and Joule heat dissipation rate has been derived. Intermediate scale (10's of km) structures of enhanced electron precipitation with peak energy fluxes ∼ 5 ergs/cm2sec (5.10-3 W/m2) and average energy ∼ 0.1 keV were associated with strong, red-dominated auroral forms (I 630.0 nm≅ 5 kR) with typical spectral ratio I 630.0/nm/I557.7 nm ≅ 5. Within these forms strong northward electric fields with peak values of ∼ 200 mV/m and Birkeland current densities ∼ 10 μA/m2 were observed. Rather complex patterns of Birkeland currents were connected to these structures. Both downward and upward directed Poynting fluxes associated with the Birkeland currents were inferred, at different latitudes within the cusp. The downward flux is dissipated as ionospheric Joule heating. Indications of additional dissipation and/or source mechanisms associated with the Poynting flux are observed in some limited regions. From correlated latitudinal variations in electric and magnetic field components, the Joule heat dissipation rate wihtin one of the auroral forms could be estimated. The dissipation rate in the center of this structure was found to be ∼ 5 times higher than the particle energy input rate. The satellite pass occurred within an interval (IMF Bz < 0) characterized by a series of short-lived (few minutes) poleward moving auroral structures, each appearing at the cusp equatorward boundary. The close latitudinal relationship between these auroral forms and the Birkeland current and ion drift structures, indicate that the latter features are of a similar transient nature, probably related to the transient injection of magnetosheath plasma elements into the dayside magnetospheric boundary

  18. Ke4 decays and Wigner cusp

    OpenAIRE

    L. Masetti

    2007-01-01

    The NA48/2 experiment at the CERN SPS collected in 2003 and 2004 large samples of the decays K+- -> pi+ pi- e+- nu (Ke4+-), K+- -> pi0 pi0 e+- nu (Ke400) and K+- -> pi0 pi0 pi+-. From the Ke4+- form factors and from the cusp in the M00^2 distribution of the K+- -> pi0 pi0 pi+- events, the pi-pi scattering lengths a00 and a20 could be extracted. This measurement is a fundamental test of Chiral Perturbation Theory (ChPT). The branching fraction and form factors of the Ke400 decay were precisely...

  19. Limit Theorems for Dispersing Billiards with Cusps

    Science.gov (United States)

    Bálint, P.; Chernov, N.; Dolgopyat, D.

    2011-12-01

    Dispersing billiards with cusps are deterministic dynamical systems with a mild degree of chaos, exhibiting "intermittent" behavior that alternates between regular and chaotic patterns. Their statistical properties are therefore weak and delicate. They are characterized by a slow (power-law) decay of correlations, and as a result the classical central limit theorem fails. We prove that a non-classical central limit theorem holds, with a scaling factor of {sqrt{nlog n}} replacing the standard {sqrt{n}} . We also derive the respective Weak Invariance Principle, and we identify the class of observables for which the classical CLT still holds.

  20. Characteristics of aortic valve dysfunction and ascending aorta dimensions according to bicuspid aortic valve morphology

    International Nuclear Information System (INIS)

    To characterize aortic valve dysfunction and ascending aorta dimensions according to bicuspid aortic valve (BAV) morphology using computed tomography (CT) and surgical findings. We retrospectively enrolled 209 patients with BAVs who underwent transthoracic echocardiography (TTE) and CT. BAVs were classified as anterior-posterior (BAV-AP) or lateral (BAV-LA) orientation of the cusps and divided according to the presence (raphe+) or absence (raphe-) of a raphe. Ascending aortic dimensions were measured by CT at four levels. BAV-AP was present in 129 patients (61.7 %) and raphe+ in 120 (57.4 %). Sixty-nine patients (33.0 %) had aortic regurgitation (AR), 70 (33.5 %) had aortic stenosis (AS), and 58 (27.8 %) had combined AS and AR. AR was more common in patients with BAV-AP and raphe+; AS was more common with BAV-LA and raphe-.Annulus/body surface area and tubular portion/body surface area diameters in patients with BAV-AP (17.1 ± 2.3 mm/m2 and 24.2 ± 5.3 mm/m2, respectively) and raphe+ (17.3 ± 2.2 mm/m2 and 24.2 ± 5.5 mm/m2, respectively) were significantly different from those with BAV-LA (15.8 ± 1.9 mm/m2 and 26.4 ± 5.5 mm/m2, respectively) and raphe- (15.7 ± 1.9 mm/m2 and 26.2 ± 5.4 mm/m2, respectively). The morphological characteristics of BAV might be associated with the type of valvular dysfunction, and degree and location of an ascending aorta dilatation. (orig.)

  1. Characteristics of aortic valve dysfunction and ascending aorta dimensions according to bicuspid aortic valve morphology

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hong Ju [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Cardiovascular Surgery, Seoul (Korea, Republic of); Yonsei University College of Medicine, Department of Cardiovascular Surgery, Seoul (Korea, Republic of); Shin, Je Kyoun; Chee, Hyun Kun; Kim, Jun Suk [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Cardiovascular Surgery, Seoul (Korea, Republic of); Ko, Sung Min [Konkuk University Medical Center, Konkuk University School of Medicine, Department of Radiology, Seoul (Korea, Republic of)

    2015-07-15

    To characterize aortic valve dysfunction and ascending aorta dimensions according to bicuspid aortic valve (BAV) morphology using computed tomography (CT) and surgical findings. We retrospectively enrolled 209 patients with BAVs who underwent transthoracic echocardiography (TTE) and CT. BAVs were classified as anterior-posterior (BAV-AP) or lateral (BAV-LA) orientation of the cusps and divided according to the presence (raphe+) or absence (raphe-) of a raphe. Ascending aortic dimensions were measured by CT at four levels. BAV-AP was present in 129 patients (61.7 %) and raphe+ in 120 (57.4 %). Sixty-nine patients (33.0 %) had aortic regurgitation (AR), 70 (33.5 %) had aortic stenosis (AS), and 58 (27.8 %) had combined AS and AR. AR was more common in patients with BAV-AP and raphe+; AS was more common with BAV-LA and raphe-.Annulus/body surface area and tubular portion/body surface area diameters in patients with BAV-AP (17.1 ± 2.3 mm/m{sup 2} and 24.2 ± 5.3 mm/m{sup 2}, respectively) and raphe+ (17.3 ± 2.2 mm/m{sup 2} and 24.2 ± 5.5 mm/m{sup 2}, respectively) were significantly different from those with BAV-LA (15.8 ± 1.9 mm/m{sup 2} and 26.4 ± 5.5 mm/m{sup 2}, respectively) and raphe- (15.7 ± 1.9 mm/m{sup 2} and 26.2 ± 5.4 mm/m{sup 2}, respectively). The morphological characteristics of BAV might be associated with the type of valvular dysfunction, and degree and location of an ascending aorta dilatation. (orig.)

  2. On the evolutionary advantage of multi-cusped teeth.

    Science.gov (United States)

    Constantino, Paul J; Bush, Mark B; Barani, Amir; Lawn, Brian R

    2016-08-01

    A hallmark of mammalian evolution is a progressive complexity in postcanine tooth morphology. However, the driving force for this complexity remains unclear: whether to expand the versatility in diet source, or to bolster tooth structural integrity. In this study, we take a quantitative approach to this question by examining the roles of number, position and height of multiple cusps in determining sustainable bite forces. Our approach is to use an extended finite-element methodology with due provision for step-by-step growth of an embedded crack to determine how fracture progresses with increasing occlusal load. We argue that multi-cusp postcanine teeth are well configured to withstand high bite forces provided that multiple cusps are contacted simultaneously to share the load. However, contact on a single near-wall cusp diminishes the strength. Location of the load points and cusp height, rather than cusp number or radius, are principal governing factors. Given these findings, we conclude that while complex tooth structures can enhance durability, increases in cusp number are more likely to be driven by the demands of food manipulation. Structural integrity of complex teeth is maintained when individual cusps remain sufficiently distant from the side walls and do not become excessively tall relative to tooth width. PMID:27558851

  3. High Energy Electron Confinement in a Magnetic Cusp Configuration

    CERN Document Server

    Park, Jaeyoung; Sieck, Paul E; Offermann, Dustin T; Skillicorn, Michael; Sanchez, Andrew; Davis, Kevin; Alderson, Eric; Lapenta, Giovanni

    2014-01-01

    We report experimental results validating the concept that plasma confinement is enhanced in a magnetic cusp configuration when beta (plasma pressure/magnetic field pressure) is order of unity. This enhancement is required for a fusion power reactor based on cusp confinement to be feasible. The magnetic cusp configuration possesses a critical advantage: the plasma is stable to large scale perturbations. However, early work indicated that plasma loss rates in a reactor based on a cusp configuration were too large for net power production. Grad and others theorized that at high beta a sharp boundary would form between the plasma and the magnetic field, leading to substantially smaller loss rates. The current experiment validates this theoretical conjecture for the first time and represents critical progress toward the Polywell fusion concept which combines a high beta cusp configuration with an electrostatic fusion for a compact, economical, power-producing nuclear fusion reactor.

  4. Talon′s cusp: Report of four unusual cases

    Directory of Open Access Journals (Sweden)

    Tulunoglu O

    2007-03-01

    Full Text Available Talon cusp is a developmental dental anomaly thought to arise as a result of evagination on the surface of a tooth crown before calcification has occurred. The etiology remains unknown. The incidence is 0.04-10%. Any tooth may have a talon cusp but most of the cases involve maxillary lateral incisors, with some instances of bilateral involvement. The anomaly has been reported to be rare in the mandible. This article reports four cases of talon cusp. The first and the second cases describe bilateral involvement of talon cusp on palatal surfaces of maxillary primary centrals; in the third case talon tubercle occurs on palatal surfaces of both maxillary permanent lateral incisors and the maxillary left central incisor and in the last case a talon cusp in the lingual surface of mandibular permanent lateral incisor.

  5. Aortic Valve Sparing in Different Aortic Valve and Aortic Root Conditions.

    Science.gov (United States)

    David, Tirone E

    2016-08-01

    The development of aortic valve-sparing operations (reimplantation of the aortic valve and remodeling of the aortic root) expanded the surgical armamentarium for treating patients with aortic root dilation caused by a variety of disorders. Young adults with aortic root aneurysms associated with genetic syndromes are ideal candidates for reimplantation of the aortic valve, and the long-term results have been excellent. Incompetent bicuspid aortic valves with dilated aortic annuli are also satisfactorily treated with the same type of operation. Older patients with ascending aortic aneurysm and aortic insufficiency secondary to dilated sinotubular junction and a normal aortic annulus can be treated with remodeling of the aortic root or with reimplantation of the aortic valve. The first procedure is simpler, and both procedures are likely equally effective. As with any heart valve-preserving procedure, patient selection and surgical expertise are keys to successful and durable repairs. PMID:27491910

  6. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... to help prevent aortic stenosis? There's no prophylactic methods that anybody can take to prevent aortic stenosis ... to progression and aortic sclerosis is not a reason to need an operation or aggressive management at ...

  7. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... opens freely when the heart contracts. On the right, we see a picture of the aortic valve ... the aortic valve because the probe is sitting right behind the aortic valve. Lots of patients on ...

  8. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... surgery in our community. Aortic stenosis is a process by which the aortic valve, which is the ... and does not open easily or appropriately. This process starts out as a disease we call aortic ...

  9. Nonlinear spectral imaging microscopy of rabbit aortic wall

    Institute of Scientific and Technical Information of China (English)

    Quangang Liu; Jianxin Chen; Shuangmu Zhuo; Xingshan Jiang; Kecheng Lu

    2009-01-01

    Employing nonlinear spectral imaging technique based on two-photon-excited fluorescence and second-harmonic generation (SHG) of biological tissue, we combine the image-guided spectral analysis method and multi-channel subsequent detection imaging to map and visualize the intrinsic species in a native rabbit aortic wall. A series of recorded nonlinear spectral images excited by a broad range of laser wavelengths (730-910 nm) are used to identify five components in the native rabbit aortic wall, including nicotinamide adenine dinucleotide (NADH), elastic fiber, flavin, porphyrin derivatives, and collagen. Integrating multi-channel subsequent detection imaging technique, the high-resolution, high contrast images of collagen and elastic fiber in the aortic wall are obtained. Our results demonstrate that this method can yield complementary biochemical and morphological information about aortic tissues, which have the potential to determine the tissue pathology associated with mechanical properties of aortic wall and to evaluate the pharmacodynamical studies of vessels.

  10. High-Energy Electron Confinement in a Magnetic Cusp Configuration

    Science.gov (United States)

    Park, Jaeyoung; Krall, Nicholas A.; Sieck, Paul E.; Offermann, Dustin T.; Skillicorn, Michael; Sanchez, Andrew; Davis, Kevin; Alderson, Eric; Lapenta, Giovanni

    2015-04-01

    We report experimental results validating the concept that plasma confinement is enhanced in a magnetic cusp configuration when β (plasma pressure/magnetic field pressure) is of order unity. This enhancement is required for a fusion power reactor based on cusp confinement to be feasible. The magnetic cusp configuration possesses a critical advantage: the plasma is stable to large scale perturbations. However, early work indicated that plasma loss rates in a reactor based on a cusp configuration were too large for net power production. Grad and others theorized that at high β a sharp boundary would form between the plasma and the magnetic field, leading to substantially smaller loss rates. While not able to confirm the details of Grad's work, the current experiment does validate, for the first time, the conjecture that confinement is substantially improved at high β . This represents critical progress toward an understanding of the plasma dynamics in a high-β cusp system. We hope that these results will stimulate a renewed interest in the cusp configuration as a fusion confinement candidate. In addition, the enhanced high-energy electron confinement resolves a key impediment to progress of the Polywell fusion concept, which combines a high-β cusp configuration with electrostatic fusion for a compact, power-producing nuclear fusion reactor.

  11. Abdominal Aortic Aneurysms: Treatments

    Science.gov (United States)

    ... access catheters Vertebroplasty Women and vascular disease Women's health Social Media Facebook Twitter ... Abdominal Aortic Aneurysms Interventional Radiologists Treat Abdominal Aneurysms Nonsurgically Interventional radiologists are vascular ...

  12. Kinematic Cusps with Two Missing Particles II: Cascade Decay Topology

    CERN Document Server

    Han, Tao; Song, Jeonghyeon

    2012-01-01

    Three-step cascade decays into two invisible particles and two visible particles via two intermediate on-shell particles develop cusped peak structures in several kinematic distributions. We study the basic properties of the cusps and endpoints in various distributions and demonstrate that the masses of the missing particles and the intermediate particles can be determined by the cusp and endpoint positions. Effects from realistic considerations such as finite decay widths, longitudinal boost of the parent particle, and spin correlations are shown to be under control for the processes illustrated.

  13. Assessment of radiation doses to the para-aortic, pelvic, and inguinal lymph nodes delivered by image-guided adaptive brachytherapy in locally advanced cervical cancer

    DEFF Research Database (Denmark)

    Mohamed, Sandy M I; Aagaard, Torben; Fokdal, Lars U; Pedersen, Erik Morre; Lindegaard, Jacob C; Tanderup, Kari

    2015-01-01

    PURPOSE: This study evaluated the dose delivered to lymph nodes (LNs) by brachytherapy (BT) and the effect of BT image-guided optimization on the LN dose. METHODS AND MATERIALS: Twenty-five patients with locally advanced cervical cancer were retrospectively analyzed, 16 patients of them had LN...

  14. Aortic arch malformations

    Energy Technology Data Exchange (ETDEWEB)

    Kellenberger, Christian J. [University Children' s Hospital, Department of Diagnostic Imaging, Zuerich (Switzerland)

    2010-06-15

    Although anomalies of the aortic arch and its branches are relatively uncommon malformations, they are often associated with congenital heart disease. Isolated lesions may be clinically significant when the airways are compromised by a vascular ring. In this article, the development and imaging appearance of the aortic arch system and its various malformations are reviewed. (orig.)

  15. Imaging in aortic dissection

    International Nuclear Information System (INIS)

    Aortic dissection (AD) is a catastrophic aortic disease. Imaging techniques play an invaluable role in the diagnostic evaluation and management of patients with AD. Major signs of AD with different imaging modalities are described in this article with a pertinent discussion on guidelines for the optimized approach of imaging study (13 refs.)

  16. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available Aortic Aneurysm Repair May 7, 2009 Good afternoon. Welcome to the Baptist Cardiac and Vascular Institute here in Miami. My name ... our live webcast. Today we’re going to repair an abdominal aortic aneurysm using a technology called ...

  17. Aortic Valve Repair: A Systematic Review and Meta-analysis of Published Literature

    Science.gov (United States)

    Fok, Matthew; Shaw, Matthew; Sancho, Elena; Abello, David; Bashir, Mohamad

    2014-01-01

    Background: It is widely accepted that aortic valve disease is surgically managed with aortic valve replacement (AVR) using different available prostheses. The long-term survival, durability of the valve, and freedom from reoperation after AVR are well established in published literature. Over the past two decades, aortic valve repair (AVr) has evolved into an accepted surgical option for patients with aortic valve disease. We review and analyze the published literature on AVr. Methods: A systematic review of the current literature was performed through three electronic databases from inception to August 2013 to identify all relevant studies relating to aortic valve repair. Articles selected were chosen by two reviewers. Articles were excluded if they contained a pediatric population or if the patient number was less than 50. Results: Twenty-four studies conformed to the inclusion criteria for inclusion in the systematic review. In total, 4986 patients underwent aortic valve repair. 7 studies represented bicuspid aortic valve (BAV) repair, 5 studies represented cusp prolapse, and 3 studies represented valve repair with root dilation or aneurysm. Overall weighted in-hospital mortality for all studies was low (1.46% ± 1.21). Preoperative aortic insufficiency (AI) ≥ 2+ did not correlate to reoperation for valve failure (Pearson's Rs 0.2705, P = 0.2585). AI at discharge was reported in 9 studies with a mean AI ≥ 2+ in 6.1% of patients. Weighted average percentage for valve reoperation following BAV repair was 10.23% ± 3.2. Weighted average reoperation following cusp prolapse repair was 3.83 ± 1.96. Weighted average reoperation in aortic valve sparing procedures with root replacement was 4.25% ± 2.46. Although there are limitations and complications of prosthetic valves, especially for younger individuals, there is ample published literature that confers strong evidence for AVR. On the contrary, aortic valve repair may be a useful option for selected patients

  18. Management of Talons Cusp associated with Primary Central Incisor: A Rare Case Report

    OpenAIRE

    Bahadure, Rakesh N.; Thosar, Nilima; Jain, Eesha S

    2012-01-01

    ABSTRACT The talon cusp is a relatively rare dental developmental anomaly characterized by cusp-like projections, usually observed on the lingual surface of the affected tooth. Normal enamel covers the cusp and fuses with the lingual aspect of the tooth. The cusp may or may not contain an extension of the pulp. The condition can occur in both the primary and permanent dentitions. However, the occurrence of anomalous cusp is rather infrequent in the primary dentition. Little data is available ...

  19. A source of error in cusp plasma leak measurements

    International Nuclear Information System (INIS)

    Plasma inhomogeneity modifies Tsub(i) in surface magnetic cusps and introduces an inequality, Tsub(iparallelB) is not equal to Tsub(i perpendicular to B), which leads to erroneous estimates of the Larmor dimension. (author)

  20. Spatially resolved study of primary electron transport in magnetic cusps

    International Nuclear Information System (INIS)

    Spatially resolved primary electron current density profiles were measured using a planar Langmuir probe in the region above a magnetic cusp in a small ion thruster discharge chamber. The probe current maps obtained were used to study the electron collection mechanics in the cusp region in the limit of zero gas flow and no plasma production, and they allowed for the visualization of primary electron transport through the cusp. Attenuation coefficients and loss widths were calculated as a function of probe distance above the anode at various operating conditions. Finally, the collection mechanics between two magnetic cusps were studied and compared. It was found that primary electron collection was dominated by the upstream magnet ring.

  1. Cusp Alfven and Plasma Electrodynamics Rocket (CAPER) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Launch a single rocket from Andoya Rocket Range into an active cusp event. Observe electric and magnetic fields, HF waves, electron and ion distributions and...

  2. Distribution of Mitral Annular and Aortic Valve Calcium as Assessed by Unenhanced Multidetector Computed Tomography.

    Science.gov (United States)

    Koshkelashvili, Nikoloz; Codolosa, Jose N; Goykhman, Igor; Romero-Corral, Abel; Pressman, Gregg S

    2015-12-15

    Aging is associated with calcium deposits in various cardiovascular structures, but patterns of calcium deposition, if any, are unknown. In search of such patterns, we performed quantitative assessment of mitral annular calcium (MAC) and aortic valve calcium (AVC) in a broad clinical sample. Templates were created from gated computed tomography (CT) scans depicting the aortic valve cusps and mitral annular segments in relation to surrounding structures. These were then applied to CT reconstructions from ungated, clinically indicated CT scans of 318 subjects, aged ≥65 years. Calcium location was assigned using the templates and quantified by the Agatston method. Mean age was 76 ± 7.3 years; 48% were men and 58% were white. Whites had higher prevalence (p = 0.03) and density of AVC than blacks (p = 0.02), and a trend toward increased MAC (p = 0.06). Prevalence of AVC was similar between men and women, but AVC scores were higher in men (p = 0.008); this difference was entirely accounted for by whites. Within the aortic valve, the left cusp was more frequently calcified than the others. MAC was most common in the posterior mitral annulus, especially its middle (P2) segment. For the anterior mitral annulus, the medial (A3) segment calcified most often. In conclusion, AVC is more common in whites than blacks, and more intense in men, but only in whites. Furthermore, calcium deposits in the mitral annulus and aortic valve favor certain locations. PMID:26517948

  3. Aortic regurgitation associated with chronic bacterial endocarditis in one adult thoroughbred gelding

    Directory of Open Access Journals (Sweden)

    CA Dörner

    2014-01-01

    Full Text Available This article describes chronic bacterial endocarditis as the cause of aortic regurgitation in a 25-year-old Thoroughbred used for horseback riding. The horse presented signs of depression, exercise intolerance, and weight loss. A pandiastolic murmur was identified, but no other clinical signs of bacterial endocarditis were identified. Haematological, serum biochemical, and urine analyses did not show any particular abnormalities. Electrocardiography showed a physiological dysrhythmia that was not pertinent to this case. Echocardiography revealed left ventricle (LV dilatation and a nodule in the left coronary cusp of the aortic valve associated with regurgitation. Based on the prevalence of aortic valve pathology in geriatric horses, a noninfectious condition with a myxomatous noninflammatory infiltrate was suspected; therefore, no special treatment was prescribed due to the absence of heart failure. Several months later, the animal was euthanised after experiencing a femur fracture. At necropsy, the horse showed an eccentric left ventricle hypertrophy and 2 nodules in the left coronary cusp of the aortic valve. Histological examination revealed the presence of bacteria, which led to the diagnosis of chronic bacterial endocarditis.

  4. Genetic integration of molar cusp size variation in baboons

    OpenAIRE

    Koh, Christina; BATES, ELIZABETH; Broughton, Elizabeth; Do, Nicholas T.; Fletcher, Zachary; Mahaney, Michael C.; Hlusko, Leslea J.

    2010-01-01

    Many studies of primate diversity and evolution rely on dental morphology for insight into diet, behavior, and phylogenetic relationships. Consequently, variation in molar cusp size has increasingly become a phenotype of interest. In 2007 we published a quantitative genetic analysis of mandibular molar cusp size variation in baboons. Those results provided more questions than answers, as the pattern of genetic integration did not fit predictions from odontogenesis. To follow up, we expanded o...

  5. Impact of Electron-Electron Cusp on Configuration Interaction Energies

    OpenAIRE

    Prendergast, David; Nolan, M.; Filippi, Claudia; Fahy, Stephen; Greer, J. C.

    2001-01-01

    The effect of the electron-electron cusp on the convergence of configuration interaction (CI) wave functions is examined. By analogy with the pseudopotential approach for electron-ion interactions, an effective electron-electron interaction is developed which closely reproduces the scattering of the Coulomb interaction but is smooth and finite at zero electron-electron separation. The exact many-electron wave function for this smooth effective interaction has no cusp at zero electron-electron...

  6. Systematics of the cusp anomalous dimension

    CERN Document Server

    Henn, J M

    2012-01-01

    We study the velocity-dependent cusp anomalous dimension in supersymmetric Yang-Mills theory. In a paper by Correa, Maldacena, Sever, and one of the present authors, a scaling limit was identified in which the ladder diagrams are dominant and are mapped onto a Schrodinger problem. We show how to solve the latter in perturbation theory and provide an algorithm to compute the solution at any loop order. The answer is written in terms of harmonic polylogarithms. Moreover, we give evidence for two curious properties of the result. Firstly, we observe that the result can be written using a subset of harmonic polylogarithms only, at least up to five loops. Secondly, we show that in a light-like limit, only single zeta values appear in the asymptotic expansion, at least up to six loops. We then extend the analysis of the scaling limit to systematically include subleading terms. This leads to a Schrodinger-type equation, but with an inhomogeneous term. We show how its solution can be computed in perturbation theory, ...

  7. Test of self-organization in beach cusp formation

    Science.gov (United States)

    Coco, Giovanni; Burnet, T. K.; Werner, B. T.; Elgar, Steve

    2003-03-01

    Field observations of swash flow patterns and morphology change are consistent with the hypothesis that beach cusps form by self-organization, wherein positive feedback between swash flow and developing morphology causes initial development of the pattern and negative feedback owing to circulation of flow within beach cusp bays causes pattern stabilization. The self-organization hypothesis is tested using measurements from three experiments on a barrier island beach in North Carolina. Beach cusps developed after the beach was smoothed by a storm and after existing beach cusps were smoothed by a bulldozer. Swash front motions were recorded on video during daylight hours, and morphology was measured by surveying at 3-4 hour intervals. Three signatures of self-organization were observed in all experiments. First, time lags between swash front motions in beach cusp bays and horns increase with increasing relief, representing the effect of morphology on flow. Second, differential erosion between bays and horns initially increases with increasing time lag, representing the effect of flow on morphology change because positive feedback causes growth of beach cusps. Third, after initial growth, differential erosion decreases with increasing time lag, representing the onset of negative feedback that stabilizes beach cusps. A numerical model based on self-organization, initialized with measured morphology and alongshore-uniform distributions of initial velocities and positions of the swash front at the beginning of a swash cycle, reproduces the measurements, except for parts of one experiment, where limited surveys and a significant low-frequency component to swash motions might have caused errors in model initialization.

  8. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... Rua, and together as a team of multidisciplinary physicians, we’re going to repair an abdominal aortic ... takes a special type of training. Both the doctors in the room are board certified and highly ...

  9. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... the age of 65. It’s most common in males. There is an increasing number, due to the ... The risk factors for abdominal aortic aneurysms are males over 60, hardening of the arteries, which is ...

  10. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... wall will actually thin out. And the big risk here is that if this gets too big ... to the aging baby boomers. Next slide. The risk factors for abdominal aortic aneurysms are males over ...

  11. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... this procedure. So let’s go back now and learn a little bit about abdominal aortic aneurysms. Great. ... And one of the things that I’m learning from this movie as we looking at these ...

  12. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... atherosclerosis, high blood pressure, smokers, or a family history of abdominal aortic aneurysms. Today’s patient is a ... screened. In fact, patients who have a family history of aneurysm, men who are smoking over the ...

  13. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... to the aging baby boomers. Next slide. The risk factors for abdominal aortic aneurysms are males over 60, ... doing a good examination and also accessing for risk factors. So we have a very integrated team here, ...

  14. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... as atherosclerosis, high blood pressure, smokers, or a family history of abdominal aortic aneurysms. Today’s patient is ... be screened. In fact, patients who have a family history of aneurysm, men who are smoking over ...

  15. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... this is to prevent rupture and to prevent death from rupture. This area just underneath the renal ... Okay. Abdominal aortic aneurysms cause approximately 15,000 deaths in the United States each year. It affects ...

  16. Aortic valve replacement

    DEFF Research Database (Denmark)

    Kapetanakis, Emmanouil I; Athanasiou, Thanos; Mestres, Carlos A;

    2008-01-01

    BACKGROUND AND AIMS OF THE STUDY: Prompted by anecdotal evidence and observations by surgeons, an investigation was undertaken into the potential differences in implanted aortic valve prosthesis sizes, during aortic valve replacement (AVR) procedures, between northern and southern European countr...... southern European countries. Imbalances in the prevalence of rheumatic heart disease, health resource availability and variations in surgical practice throughout Europe might be possible etiological causes....

  17. Are Aortic Stent Grafts Safe in Pregnancy?

    OpenAIRE

    Nader Khandanpour; Mehta, Tapan A.; Adiseshiah, M; Meyer, Felicity J.

    2015-01-01

    Aortic stent grafts are increasingly used to treat aortic aneurysms and also other aortic pathologies. The safety of aortic stent grafts in pregnancy has never been studied or reported. We report on two cases of aortic stent grafts in pregnant women and discuss the effect of pregnancy on these aortic stent grafts.

  18. The interaction between transpolar arcs and cusp spots

    CERN Document Server

    Fear, R C; Carter, J A; Maggiolo, R

    2016-01-01

    Transpolar arcs and cusp spots are both auroral phenomena which occur when the interplanetary magnetic field is northward. Transpolar arcs are associated with magnetic reconnection in the magnetotail, which closes magnetic flux and results in a "wedge" of closed flux which remains trapped, embedded in the magnetotail lobe. The cusp spot is an indicator of lobe reconnection at the high-latitude magnetopause; in its simplest case, lobe reconnection redistributes open flux without resulting in any net change in the open flux content of the magnetosphere. We present observations of the two phenomena interacting--i.e., a transpolar arc intersecting a cusp spot during part of its lifetime. The significance of this observation is that lobe reconnection can have the effect of opening closed magnetotail flux. We argue that such events should not be rare.

  19. Aortic regurgitation after transcatheter aortic valve replacement.

    Science.gov (United States)

    Werner, Nikos; Sinning, Jan-Malte

    2014-01-01

    Paravalvular aortic regurgitation (AR) negatively affects prognosis following transcatheter aortic valve replacement (TAVR). As transcatheter heart valves (THV) are anchored using a certain degree of oversizing at the level of the aortic annulus, incomplete stent frame expansion because of heavily annular calcifications, suboptimal placement of the prosthesis, and/or annulus-prosthesis size-mismatch can contribute to paravalvular AR with subsequent increased mortality risk. Echocardiography is essential to differentiate between transvalvular and paravalvular AR and to further elucidate the etiology of AR during the procedure. However, because echocardiographic quantification of AR in TAVR patients remains challenging, especially in the implantation situation, a multimodal approach to the evaluation of AR with use of hemodynamic measurements and imaging modalities is useful to precisely quantify the severity of AR immediately after valve deployment. "Next-generation" THVs are already on the market and first results show that paravalvular AR related to design modifications (eg, paravalvular space-fillers, full repositionability) are rarely seen in these valve types.  PMID:24632758

  20. Energetic particle sounding of the magnetospheric cusp with ISEE-1

    Directory of Open Access Journals (Sweden)

    K. E. Whitaker

    2007-06-01

    Full Text Available Observations on 30 October 1978 show the ISEE-1 spacecraft passing though the high-altitude dayside northern magnetospheric cusp region from roughly 16:00 to 18:30 UT, during a slow solar wind period (~380 km/s. More than two orders of magnitude enhancements of the cusp energetic particle (CEP fluxes were observed along with a depressed and turbulent local magnetic field. The observed variations of the pitch angle distributions (PAD provide a unique opportunity to determine the structure of the cusp and the origin of the CEP. Through a boundary sounding technique, the location and orientation of the cusp poleward (or backside boundary was observed for almost 10 min during which time it appeared initially to be stationary in the GSM/GSE X-direction and then moved sunward about 0.12 Earth radii (RE. The orientation remained approximately perpendicular to the GSM/GSE X-axis until it was observed to rotate by 60 degrees in ~3 min before ISEE-1 was fully inside the cusp cavity. The cavity itself was filled with CEP fluxes displaying large anisotropies, indicative of their source being located below (Earthward of the satellite location. The spacecraft entered from the backside of the cusp, then traveled ~4 RE through the cavity, and exited through the "top" of the cavity leaving a region of energetic ions below. The PADs demonstrate that the bow shock cannot be the main source of the observed CEPs. The CEP fluxes were measured at about 8.5 h MLT when the IMF had both an 8–10 nT duskward and southward component.

  1. Multi-point observations of intermittency in the cusp regions

    Directory of Open Access Journals (Sweden)

    M. M. Echim

    2007-08-01

    Full Text Available In this paper we investigate the statistical properties of magnetic field fluctuations measured by the four Cluster spacecraft in the cusp and close to the interface with the magnetospheric lobes, magnetopause and magnetosheath. At lower altitudes along the outbound orbit of 26 February 2001, the magnetic field fluctuations recorded by all four spacecraft are random and their Probability Distribution Functions (PDFs are Gaussian at all scales. The flatness parameter, F – related to the kurtosis of the time series, is equal to 3. At higher altitudes, in the cusp and its vicinity, closer to the interface with the magnetopause and magnetosheath, the PDFs from all Cluster satellites are non-Gaussian and show a clear intermittent behavior at scales smaller than τG≈ 61 s (or 170 km. The flatness parameter increases to values greater than 3 for scales smaller than τG. A Haar wavelet transform enables the identification of the "events" that produce sudden variations of the magnetic field and of the scales that have most of the power. The LIM parameter (i.e. normalized wavelet power indicates that events for scales below 65 s are non-uniformly distributed throughout the cusp passage. PDFs, flatness and wavelet analysis show that at coarse-grained scales larger than τG the intermittency is absent in the cusp. Fluctuations of the magnetic energy observed during the same orbit in the magnetosheath show PDFs that tend toward a Gaussian at scales smaller than τG found in the cusp. The flatness analysis confirms the decreasing of τG from cusp to magnetosheath. Our analysis reveals the turbulent cusp as a transition region from a non-intermittent turbulent state inside the magnetosphere to an intermittent turbulent state in the magnetosheath that has statistical properties resembling the solar wind turbulence. The observed turbulent fluctuations in the cusp suggests a phenomenon of nonlinear

  2. Nonadiabatic scattering and transport at the spindle cusp

    International Nuclear Information System (INIS)

    When magnetohydrodynamics is used to describe plasma flow across a separatrix to open field lines, the transport is modeled by a diffusion equation with a sink for particles on the open lines. In that case, it is assumed that plasma is carried to and from the separatrix by diffusive processes. The purpose of this note is to discuss the nonadiabatic processes occurring at a spindle cusp to transfer plasma across a separatrix. After an ion is delivered to the vicinity of the separatrix by diffusion it enters the spindle cusp and will skip back and forth across the separatrix, producing a structured transport not seen with MHD

  3. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... aortic stenosis, are there any activities that I should avoid doing? That's a great question, Jim. Generally ... do not have symptoms but have aortic stenosis should be considered for surgery. Age, in and of ...

  4. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... who have symptomatic aortic stenosis of a severe nature. It's even been liberalized in some patient populations ... the heart. The aortic valve, because of its nature being in back of the heart, is not ...

  5. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... up offering patients aortic valve surgery in our community. Aortic stenosis is a process by which the ... basic valve types that we use in our practice, those being tissue valves and mechanical valves. Tissue ...

  6. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... North Carolina. My name is John Streitman and I'm a cardiothoracic surgeon here at the Heart ... the corrective surgery of aortic valve replacement. If I have aortic stenosis, are there any activities that ...

  7. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... of that slide, that demonstrates that patients with New York Heart Association class heart failure 1 and ... right down the aortic valve and that's the new aortic valve that Dr. Streitman's placed. And you ...

  8. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... to help prevent aortic stenosis? There's no prophylactic methods that anybody can take to prevent aortic stenosis ... it will be archived on the ORlive Web site and ORlive.com and, of course, a link ...

  9. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... conditions or other significant medical problems, the American College of Cardiology recommends aortic valve replacement for basically ... more likely we see aortic stenosis. Again, patient education is part of the evaluation and management of ...

  10. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... see aortic stenosis in patients younger, in their 40s and 50s, if they have congenitally bicuspid, or ... a year and, you know, probably 30 to 40 minimally invasive aortic valve replacements a year. So ...

  11. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... Hospital in Pinehurst, North Carolina. During the program, it's easy for you to learn about the procedure. ... the aortic valve, and proceeds to aortic stenosis. It's really not felt to be due to wear ...

  12. Aneurysms: thoracic aortic aneurysms.

    Science.gov (United States)

    Chun, Kevin C; Lee, Eugene S

    2015-04-01

    Thoracic aortic aneurysms (TAAs) have many possible etiologies, including congenital heart defects (eg, bicuspid aortic valves, coarctation of the aorta), inherited connective tissue disorders (eg, Marfan, Ehlers-Danlos, Loeys-Dietz syndromes), and degenerative conditions (eg, medial necrosis, atherosclerosis of the aortic wall). Symptoms of rupture include a severe tearing pain in the chest, back, or neck, sometimes associated with cardiovascular collapse. Before rupture, TAAs may exert pressure on other thoracic structures, leading to a variety of symptoms. However, most TAAs are asymptomatic and are found incidentally during imaging for other conditions. Diagnosis is confirmed with computed tomography scan or echocardiography. Asymptomatic TAAs should be monitored with imaging at specified intervals and patients referred for repair if the TAAs are enlarging rapidly (greater than 0.5 cm in diameter over 6 months for heritable etiologies; greater than 0.5 cm over 1 year for degenerative etiologies) or reach a critical aortic diameter threshold for elective surgery (5.5 cm for TAAs due to degenerative etiologies, 5.0 cm when associated with inherited syndromes). Open surgery is used most often to treat asymptomatic TAAs in the ascending aorta and aortic arch. Asymptomatic TAAs in the descending aorta often are treated medically with aggressive blood pressure control, though recent data suggest that endovascular procedures may result in better long-term survival rates. PMID:25860136

  13. Quantitative assessment of an aortic and pulmonary valve function according to valve fenestration

    International Nuclear Information System (INIS)

    There are some reasons for malfunction of aortic and pulmonary valve like fibrosis, calcification, and atheroma. Although, in some papers fenestration were known as a pathologic sign, but it is not generally accepted, while this matter is important in choosing suitable Homograft Heart Valve. In this paper fenestrations and its size, numbers and situation effect was studied. We collected 98 hearts, the donors died because of accident, we excluded valves with atheroma, calcification, fibrosis and unequal cusps, 91 aortic and 93 pulmonary valves were given further consideration. We classified valves according to situation, number and size of fenestration. Each valve was tested with 104 cm of non-nal saline column pressure which is equal to 76 mm Hg. Valve efficacy was detected by fluid flow assay. With study of 184 valves, 95 had no fenestration, 64 had less than 2 fenestration and 25 had more than 2 fenestration. Valve efficacy in condition of less than 2 fenestration was more than others (p <0.01). Malfunction effects of fenestration increased in larger valve and it will be decreased if their situation would be marginal (free margin of cusp). In the comparison of aortic and pulmonary valve we saw that malfunction effect of fenestration in pulmonary valve was more than aortic valve. Our experience in Immam Khomeini Homograft Valve Bank has shown that a great deal of valves is fenestrated. It seems that fenestration must be considered as a quality criterion in homograft valve preparation, especially in pulmonary and large aortic valves; but complementary studies is necessary

  14. A rare report of mandibular facial talon cusp and its management

    Directory of Open Access Journals (Sweden)

    Sivakumar Nuvvula

    2014-01-01

    Full Text Available Talon cusp is an uncommon dental anomaly showing morphologically well delineated, accessory cusp-like structure projecting from cingulum to the incisal edge of anterior teeth. This anomaly is rare in the mandibular dentition and rarer on the facial aspect. A case of this infrequent entity of mandibular facial talon cusp and its management is reported here.

  15. Aortic dissection: case series

    Directory of Open Access Journals (Sweden)

    Bhavana Venkata Nagabhushana Rao

    2016-04-01

    Full Text Available Aortic dissection may not be attended by a physician in his lifetime, but he should possess all the clinical acumen to deal with as it is a catastrophic disease. Early and accurate diagnosis will save a life. Here we present three cases we faced in sequence over a period of two months. A case of extensive dissection arch to thoracic aorta, its display in detail. Second case eliciting ambiguity between coronary ischemia and aortic dissection. Management difficulties of such clinician situation are discussed. Third case, the fracture of a renal artery stent leading to severe hypertension, abdominal pain, and aortic dissection. Such case was not described in the literature to our knowledge. [Int J Res Med Sci 2016; 4(4.000: 1268-1271

  16. ULF Narrowband Emissions Analysis in the Terrestrial Polar Cusps

    Czech Academy of Sciences Publication Activity Database

    Grison, Benjamin; Píša, David

    San Francisco : AGU, 2013. SM33A-03. [Meeting of the Americas 2013. 14.05.2013-17.05.2013, Cancun] Institutional support: RVO:68378289 Keywords : Cusp * Plasma wave s and instabilities Subject RIV: BL - Plasma and Gas Discharge Physics http://abstractsearch.agu.org/meetings/2013/JA/sections/SM/sessions/SM33A/abstracts/SM33A-03.html

  17. Hydromagnetic model of the dayside cusp of the Earth magnetosphere

    International Nuclear Information System (INIS)

    Investigation into the stationary MHD-equations describing quasi-viscous flow in the dayside cusp of the magnetosphere was carried out. The effect of 3 zone magnetospheric-ionospheric currents on the restricted flow of solar wind in the magnetospheric hollow is discussed

  18. Cluster Observations of Ion Dispersions near the Exterior Cusp

    Czech Academy of Sciences Publication Activity Database

    Escoubet, C. P.; Grison, Benjamin; Berchem, J.; Trattner, K. J.; Pitout, F.; Richard, R. L.; Taylor, M. G.; Laakso, H.; Masson, A.; Dunlop, M. W.; Dandouras, I.; Reme, H.; Fazakerley, A. N.; Daly, P.

    San Francisco : AGU, 2013. SM11B-2077. [AGU Fall Meeting 2013. 09.12.2013-13.12.2013, San Francisco] Institutional support: RVO:68378289 Keywords : Cusp * Solar wind/magnetosphere interactions Subject RIV: BL - Plasma and Gas Discharge Physics http://abstractsearch.agu.org/meetings/2013/FM/sections/SM/sessions/SM11B/abstracts/SM11B-2077.html

  19. Regularity of the eta function on manifolds with cusps

    OpenAIRE

    Loya, Paul; Moroianu, Sergiu; Park, Jinsung

    2009-01-01

    On a spin manifold with conformal cusps, we prove under an invertibility condition at infinity that the eta function of the twisted Dirac operator has at most simple poles and is regular at the origin. For hyperbolic manifolds of finite volume, the eta function of the Dirac operator twisted by any homogeneous vector bundle is shown to be entire.

  20. A super-cusp divertor configuration for tokamaks

    International Nuclear Information System (INIS)

    Our study demonstrates a remarkable flexibility of advanced divertor configurations created with the remote poloidal field coils. The emphasis here is on the configurations with three poloidal field nulls in the divertor area. We are seeking the structures where all three nulls lie on the same separatrix, thereby creating two zones of a very strong flux expansion, as envisaged in the concept of Takase's cusp divertor. It turns out that the set of remote coils can produce a cusp divertor, with additional advantages of: (i) a large stand-off distance between the divertor and the coils and (ii) a thorough control that these coils exert over the fine features of the configuration. In reference to these additional favourable properties acquired by the cusp divertor, the resulting configuration could be called 'a super-cusp'. General geometrical features of the three-null configurations produced by remote coils are described. Furthermore, issues on the way to practical applications include the need for a more sophisticated control system and possible constraints related to excessively high currents in the divertor coils

  1. Oxygen Ion Heat Rate within Alfvenic Turbulence in the Cusp

    Science.gov (United States)

    Coffey, Victoria N.; Singh, Nagendra; Chandler, Michael O.

    2009-01-01

    The role that the cleft/cusp has in ionosphere-magnetosphere coupling makes it a dynamic and important region. It is directly exposed to the solar wind, making it possible for the entry of electromagnetic energy and precipitating electrons and ions from dayside reconnection and other dayside events. It is also a significant source of ionospheric plasma, contributing largely to the mass loading of the magnetosphere with large fluxes of outflowing ions. Crossing the cusp/cleft near 5100 km, the Polar instruments observe the common correlation of downward Poynting flux, ion energization, soft electron precipitation, broadband extremely low-frequency (BB-ELF) emissions, and density depletions. The dominant power in the BB-ELF emissions is now identified to be from spatially broad, low frequency Alfv nic structures. For a cusp crossing, we determine using the Electric Field Investigation (EFI), that the electric and magnetic field fluctuations are Alfv nic and the electric field gradients satisfy the inequality for stochastic acceleration. With all the Polar 1996 horizontal crossings of the cusp, we determine the O+ heating rate using the Thermal Ion Dynamics Experiment (TIDE) and Plasma Wave Investigation (PWI). We then compare this heating rate to other heating rates assuming the electric field gradient criteria exceeds the limit for stochastic acceleration for the remaining crossings. The comparison suggests that a stochastic acceleration mechanism is operational and the heating is controlled by the transverse spatial scale of the Alfvenic waves.

  2. Conformal SO(2,4) Transformations of the One-Cusp Wilson Loop Surface

    OpenAIRE

    Ryang, Shijong

    2007-01-01

    By applying the conformal SO(2,4) transformations to the elementary one-cusp Wilson loop surface we construct various two-cusp and four-cusp Wilson loop surface configurations in AdS_5 and demonstrate that they solve the string equations of the Nambu-Goto string action. The conformal boosts of the basic four-cusp Wilson loop surface with a square-form projection generate various four-cusp Wilson loop surfaces with projections of the rescaled square, the rhombus and the trapezium, on which sur...

  3. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... to repair an abdominal aortic aneurysm using a technology called an “endograft,” which is sometimes called the “ ... separate area, and it’s because of this small technology that allows you to do this. Exactly. So ...

  4. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... the arteries, which is known as atherosclerosis, high blood pressure, smokers, or a family history of abdominal aortic ... imaging. We can integrate ultrasound imaging, the patient’s blood pressure, and so it’s a little bit like being ...

  5. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... an abdominal aortic aneurysm. Normally this procedure takes us about 45 minutes to an hour of doctor work time, which is, I think, a fairly quick procedure to replace a major life-threatening problem in the patient’s abdomen. So you can see ...

  6. CT and MR imaging of the aortic valve: radiologic-pathologic correlation.

    Science.gov (United States)

    Bennett, Christopher J; Maleszewski, Joseph J; Araoz, Philip A

    2012-01-01

    Valvular disease is estimated to account for as many as 20% of cardiac surgical procedures performed in the United States. It may be congenital in origin or secondary to another disease process. One congenital anomaly, bicuspid aortic valve, is associated with increased incidence of stenosis, regurgitation, endocarditis, and aneurysmal dilatation of the aorta. A bicuspid valve has two cusps instead of the normal three; resultant fusion or poor excursion of the valve leaflets may lead to aortic stenosis, the presence of which is signaled by dephasing jets on magnetic resonance (MR) images. Surgery is generally recommended for patients with severe stenosis who are symptomatic or who have significant ventricular dysfunction; transcatheter aortic valve implantation (TAVI) is an emerging therapeutic option for patients who are not eligible for surgical treatment. Computed tomography (CT) is an essential component of preoperative planning for TAVI; it is used to determine the aortic root dimensions, severity of peripheral vascular disease, and status of the coronary arteries. Aortic regurgitation, which is caused by incompetent closure of the aortic valve, likewise leads to the appearance of jets on MR images. The severity of regurgitation is graded on the basis of valvular morphologic parameters; qualitative assessment of dephasing jets at Doppler ultrasonography; or measurements of the regurgitant fraction, volume, and orifice area. Mild regurgitation is managed conservatively, whereas severe or symptomatic regurgitation usually leads to valve replacement surgery, especially in the presence of substantial left ventricular enlargement or dysfunction. Bacterial endocarditis, although less common than aortic stenosis and regurgitation, is associated with substantial morbidity and mortality. Electrocardiographically gated CT reliably demonstrates infectious vegetations and benign excrescences of 1 cm or more on the valve surface, allowing the assessment of any embolic

  7. Cine MRI of the ascending aorta in the elderly with respect to the flow signal void and aortic valve morphology

    International Nuclear Information System (INIS)

    Cine flow MRI was performed on a 1.5 Tesla system to observe signal intensity of blood flow within the ascending aorta in the elderly who had no aortic stenosis and to determine frequency of the flow signal void. Coronal and sagittal imaging planes of the ascending aorta were obtained in 27 aged patients with no known cardiac diseases (14 men and 13 women, mean age of 76) and 7 young volunteers (7 men, mean age of 24), utilizing ECG-gating, GRASS (gradient-recalled acquisition in steady state), and a flow compensation sequence. The young volunteers presented little or no signal void within the ascending aorta. In 26 (96%) of the 27 aged patients, on the other hand, signal void was demonstrated in the blood flow distal to the aortic valve during systole. The maximum length of the signal void that was measured at 318∼632 msec after the R wave of ECG ranged from 33 to 97 mm. Conventional and Doppler echocardiography was used to evaluate motion and morphology of the aortic valve in 19 of the 27 aged patients. Eighteen of these 19 subjects had aortic signal void on cine MRI. Echocardiography showed sclerotic changes of the aortic valve (i.e., increased echogenicity of the cusps and/or commissure fusion) in 10 (53%) of the 19 subjects. The mean maximum length of the signal void in the 10 patients with aortic valve sclerosis was significantly greater than that in the 9 patients with echocardiographically normal valve (68 vs.45 mm, p<0.01). These results suggest that signal void of blood flow in the ascending aorta, which is recognized as one of the characteristic findings in patients with aortic stenosis, is not a specific feature for this disease but rather a commom one in the elderly particularly those with sclerotic changes of the aortic valve. However, the length of the signal void may distinguish between nonstenotic and stenotic aortic valves. (author)

  8. Aortic valve annuloplasty: new single suture technique.

    Science.gov (United States)

    Schöllhorn, Joachim; Rylski, Bartosz; Beyersdorf, Friedhelm

    2014-06-01

    Reconstruction strategies for aortic valve insufficiency in the presence of aortic annulus dilatation are usually surgically challenging. We demonstrate a simple, modified Taylor technique of downsizing and stabilization of the aortic annulus using a single internal base suture. Since April 2011, 22 consecutive patients have undergone safe aortic valve annuloplasty. No reoperations for aortic valve insufficiency and no deaths occurred. PMID:24882316

  9. Calcific Aortic Valve Disease: Part 1-Molecular Pathogenetic Aspects, Hemodynamics, and Adaptive Feedbacks.

    Science.gov (United States)

    Pasipoularides, Ares

    2016-04-01

    Aortic valvular stenosis (AVS), produced by calcific aortic valve disease (CAVD) causing reduced cusp opening, afflicts mostly older persons eventually requiring valve replacement. CAVD had been considered "degenerative," but newer investigations implicate active mechanisms similar to atherogenesis-genetic predisposition and signaling pathways, lipoprotein deposits, chronic inflammation, and calcification/osteogenesis. Consequently, CAVD may eventually be controlled/reversed by lifestyle and pharmacogenomics remedies. Its management should be comprehensive, embracing not only the valve but also the left ventricle and the arterial system with their interdependent morphomechanics/hemodynamics, which underlie the ensuing diastolic and systolic LV dysfunction. Compared to even a couple of decades ago, we now have an increased appreciation of genomic and cytomolecular pathogenetic mechanisms underlying CAVD. Future pluridisciplinary studies will characterize better and more completely its pathobiology, evolution, and overall dynamics, encompassing intricate feedback processes involving specific signaling molecules and gene network cascades. They will herald more effective, personalized medicine treatments of CAVD/AVS. PMID:26891845

  10. First direct aortic retrievable transcatheter aortic valve implantation in humans.

    Science.gov (United States)

    Chandrasekhar, Jaya; Glover, Chris; Labinaz, Marino; Ruel, Marc

    2014-11-01

    We describe 2 cases in which transcatheter aortic valve implantation was performed with a Portico prosthesis (St Jude Medical, St Paul, MN) through a direct aortic approach. In 1 of the cases, prosthesis retrieval was needed during the procedure and was essential to the successful outcome. This is the first report, to our knowledge, of direct aortic Portico prosthesis implantation, and it highlights the significance of the retrievable nature of this device. PMID:25442452

  11. An alternative singularity-free cosmological scenario from cusp geometries

    CERN Document Server

    Rosa, Reinaldo R; Stalder, Diego H

    2012-01-01

    We study an alternative geometrical approach on the problem of classical cosmological singularity. It is based on a generalized function $f (x, y) = x^{2} + y^{2} = (1 - z)z^{n}$ which consists of a cusped coupled isosurface. Such a geometry is computed and discussed into the context of Friedmann singularity-free cosmology where a pre-big bang scenario is considered. Assuming that the mechanism of cusp formation is described by non-linear oscillations of a pre-big bang extended very high energy density field ($> 3 \\times 10^{94} kg/m^{3} $), we show that the action under the gravitational field follows a tautochrone of revolution, understood here as the primary projected geometry that alternatively replaces the Friedmann singularity in the standard big bang theory. As shown here this new approach allows us to interpret the nature of both matter and dark energy from first geometric principles.

  12. Thoracic aortic aneurysm and dissection.

    Science.gov (United States)

    Goldfinger, Judith Z; Halperin, Jonathan L; Marin, Michael L; Stewart, Allan S; Eagle, Kim A; Fuster, Valentin

    2014-10-21

    Aortic dissection is the most devastating complication of thoracic aortic disease. In the more than 250 years since thoracic aortic dissection was first described, much has been learned about diseases of the thoracic aorta. In this review, we describe normal thoracic aortic size; risk factors for dissection, including genetic and inflammatory conditions; the underpinnings of genetic diseases associated with aneurysm and dissection, including Marfan syndrome and the role of transforming growth factor beta signaling; data on the role for medical therapies in aneurysmal disease, including beta-blockers, angiotensin receptor blockers, and angiotensin-converting enzyme inhibitors; prophylactic surgery for aneurysm; surgical techniques for the aortic root; and surgical and endovascular management of aneurysm and dissection for different aortic segments. PMID:25323262

  13. Can a stochastic cusp catastrophe model explain stock market crashes?

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Vošvrda, Miloslav

    2009-01-01

    Roč. 33, č. 10 (2009), s. 1824-1836. ISSN 0165-1889 R&D Projects: GA ČR GD402/09/H045; GA ČR GA402/09/0965 Grant ostatní: GAUK(CZ) 46108 Institutional research plan: CEZ:AV0Z10750506 Keywords : Stochastic cusp catastrophe * Bifurcations * Singularity * Nonlinear dynamics * Stock market crash Subject RIV: AH - Economics Impact factor: 1.097, year: 2009

  14. Magneto Inertial Fusion Based on a Cusp Field Configuration

    OpenAIRE

    Ryzhkov, S. V.; Kostyukov, I. Yu.

    2009-01-01

    We study the cusp configuration of pre-seeded magnetic field for laser-driven flux-compression. The proposed configuration provides better particle confinement than that in Ref. [O.V. Gotchev et al., Journal of Fusion Energy 27 (2008) 25-31.] thereby leading to better magnetic insulation of hot fusion plasma. We develop the model that takes into account (i) magnetized target implosion, (ii) magnetic flux compression; (iii) particle losses from magnetic trap. The key parameter governing the pr...

  15. Dispersive representation of K -> 3 pi amplitudes and cusps

    OpenAIRE

    Kampf, Karol; Knecht, Marc; Novotny, Jiri; Zdrahal, Martin

    2008-01-01

    The NA48/2 collaboration has shown clear experimental evidence for a cusp in the data for K -> pi pi^0 pi^0. This effect can be used to extract information on the pi-pi scattering lengths. We address this issue using a two-loop dispersive construction of pi pi -> pi pi and K -> pi pi pi amplitudes in the presence of isospin breaking.

  16. Plasma Structure and Behavior of Miniature Ring-Cusp Discharges

    OpenAIRE

    Mao, Hann-Shin

    2013-01-01

    Miniature ring-cusp ion thrusters provide a unique blend of high efficiencies and millinewton level thrust for future spacecraft. These thrusters are attractive as a primary propulsion for small satellites that require a high delta V, and as a secondary propulsion for larger spacecraft that require precision formation flying, disturbance rejection, or attitude control. To ensure desirable performance throughout the life of such missions, an advancement in the understanding of the plasma struc...

  17. Sex assessment efficacy of permanent maxillary first molar cusp dimensions in Indians

    Science.gov (United States)

    Yadav, Achla Bharti; Angadi, Punnya V.; Yadav, Sumit Kumar

    2015-01-01

    Background: The human first maxillary molar provides clues about evolution and is functionally important. It has four main cusps, and each cusp has an independent growth pattern and different evolutionary background. Though less explored, the analysis based on measurement of each cusp appears to be more meaningful biologically than conventional measurements of the whole crown. Aim: This study aimed to demonstrate the extent of sexual dimorphism in permanent maxillary first molar cusp diameters and their potential utility in sex prediction among Indians using logistic regression analysis (LRA). Materials and Methods: The mesiodistal and buccolingual (BL) crown diameters along with cusp dimensions and cusp indices of right maxillary first molar were measured in an Indian sample (149 males, 151 females; age range of 18–30 years). The possible sex dimorphism in these parameters was evaluated, and LRA was performed to ascertain their usefulness in sex prediction. Results: BL crown dimension and the hypocone (distolingual) cusp showed the highest sexual dimorphism. The combination of metacone and hypocone, i.e., distal cusp diameters among cusp parameters showed the highest accuracy (61.3%). While, on combining all the crown and cusp diameters together the overall accuracy was raised (64.3%). Conclusion: This study supports the ontogeny hypothesis suggesting that early-forming mesial cusps demonstrate less sexual variation as compared to subsequently formed distal cusps in the maxillary molar. Though the sex identification accuracy for cusp diameters of the permanent maxillary first molar in Indians is relatively moderate (≈61%), it can be used as an adjunct for sexing of adult Indians in forensic contexts. PMID:26681853

  18. Cusp-core problem and strong gravitational lensing

    Institute of Scientific and Technical Information of China (English)

    Nan Li; Da-Ming Chen

    2009-01-01

    Cosmological numerical simulations of galaxy formation have led to the cuspy density profile of a pure cold dark matter halo toward the center,which is in sharp contradiction with the observations of the rotation curves of cold dark matter-dominated dwarf and low surface brightness disk galaxies,with the latter tending to favor mass profiles with a fiat central core.Many efforts have been devoted to resolving this cusp-core problem in recent years,among them,baryon-cold dark matter interactions are considered to be the main physical mechanisms erasing the cold dark matter (CDM) cusp into a flat core in the centers of all CDM halos.Clearly,baryon-cold dark matter interactions are not customized only for CDM-dominated disk galaxies,but for all types,including giant ellipticals.We first fit the most recent high resolution observations of rotation curves with the Burkert profile,then use the constrained core size-halo mass relation to calculate the lensing frequency,and compare the predicted results with strong lensing observations.Unfortunately,it turns out that the core size constrained from rotation curves ofdisk galaxies cannot be extrapolated to giant ellipticals.We conclude that,in the standard cosmological paradigm,baryon-cold dark matter interactions are not universal mechanisms for galaxy formation,and therefore,they cannot be true solutions to the cusp-core problem.

  19. Abdominal aortic aneurysm surgery

    DEFF Research Database (Denmark)

    Gefke, K; Schroeder, T V; Thisted, B; Olsen, P S; Perko, M J; Agerskov, Kim; Røder, O; Lorentzen, Jørgen Ewald

    1994-01-01

    The goal of this study was to identify patients who need longer care in the ICU (more than 48 hours) following abdominal aortic aneurysm (AAA) surgery and to evaluate the influence of perioperative complications on short- and long-term survival and quality of life. AAA surgery was performed in 55......, 78% stated that their quality of life had improved or was unchanged after surgery and had resumed working. These data justify a therapeutically aggressive approach, including ICU therapy following AAA surgery, despite failure of one or more organ systems.......The goal of this study was to identify patients who need longer care in the ICU (more than 48 hours) following abdominal aortic aneurysm (AAA) surgery and to evaluate the influence of perioperative complications on short- and long-term survival and quality of life. AAA surgery was performed in 553...

  20. Structure of the outer cusp and sources of the cusp precipitation during intervals of a horizontal IMF

    Czech Academy of Sciences Publication Activity Database

    Němeček, Z.; Šafránková, J.; Přech, L.; Šimůnek, Jiří; Sauvaud, J.A.; Fedorov, A.; Stenuit, H.; Fuselier, S. A.; Savin, S.; Zelenyi, L.; Berchem, J.

    2003-01-01

    Roč. 108, A12 (2003), s. 6-1-6-18. ISSN 0148-0227 R&D Projects: GA ČR GA205/02/0947 Grant ostatní: GA UK(CZ) 191/02 Institutional research plan: CEZ:AV0Z3042911; CEZ:MSM 113200004 Keywords : cusp * boundary layers * reconnection * magnetopause Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.992, year: 2003

  1. 3-D mesoscale MHD simulations of magnetospheric cusp-like configurations: cusp diamagnetic cavities and boundary structure

    Directory of Open Access Journals (Sweden)

    E. Adamson

    2012-02-01

    Full Text Available We present results from mesoscale simulations of the magnetospheric cusp region for both strongly northward and strongly southward interplanetary magnetic field (IMF. Simulation results indicate an extended region of depressed magnetic field and strongly enhanced plasma β which exhibits a strong dependence on IMF orientation. These structures correspond to the Cusp Diamagnetic Cavities (CDC's. The typical features of these CDC's are generally well reproduced by the simulation. The inner boundaries between the CDC and the magnetosphere are gradual transitions which form a clear funnel shape, regardless of IMF orientation. The outer CDC/magnetosheath boundary exhibits a clear indentation in both the x-z and y-z planes for southward IMF, while it is only indented in the x-z plane for northward, with a convex geometry in the y-z plane. The outer boundary represents an Alfvénic transition, mostly consistent with a slow-shock, indicating that reconnection plays an important role in structuring the high-altitude cusp region.

  2. Acute aortic intramural hematoma

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Oh Keun; Choi, Yo Won; Kim, Kwon Hyung; Jeon, Seok Chol; Park, Choong Kee; Seo, Heung Suk; Hahm, Chang Kok [Hanyang Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-02-01

    To evaluate the radiologic findings of acute intramural hematoma of the aorta, and the clinical follow up thereof. Among 34 cases confirmed clinically and radiologically as aortic dissection, and analysis was carried out based on 15 cases in which intramural hematoma without false lumen was demonstrated, on initial CT, 12 cases of in which follow up CT was used and five cases involving an aortogram. Elements such as the shape of the thickened aortic wall, ulcer-like intimal defects, and intimal calcification were examined. Changes in these elements were also examined on follow-up CT. DeBackey types 1 and 3 accounted for one and 14 cases, respectively. Initial precontrast CT demonstrated continuous, crescentic high attenuation areas along the wall of the descending aorta. In postcontrast scans, the crescentic areas were of relatively lower-attenuation and appeared along the aorta wall. Displaced intimal calcifications were seen in nine of fifteen patients. There was no intimal flap on all five aortogram, while aortic wall thickening and atherosclerotic change were demonstrated in four cases and in one case, respectively. Focal ulcers were seen in three cases. Ulcer-like intimal defects were demonstrated in a total of eleven cases (eight on CT, two on aortogram, and one on both). In ten of the twelve cases seen on follow up CT, the thickness of the intramural hematoma was seen to be reduced. Among the 15 cases, the operation was performed in two cases, and the remaining 13 received conservative treatment. In ten cases observed for more than twelve months, a recurrence of symptoms did not occur. Eccentric aortic wall thickening in patients who complain of acute chest pain is the result of acute aortic dissection with intramural hematoma, or a penetrating atherosclerotic ulcer of the aorta. The later may be differentiated from the former by the presence of on ulcer-like intimal defect. When both diseases are limited to the descending aorta, conservative treatment may

  3. Acute aortic intramural hematoma

    International Nuclear Information System (INIS)

    To evaluate the radiologic findings of acute intramural hematoma of the aorta, and the clinical follow up thereof. Among 34 cases confirmed clinically and radiologically as aortic dissection, and analysis was carried out based on 15 cases in which intramural hematoma without false lumen was demonstrated, on initial CT, 12 cases of in which follow up CT was used and five cases involving an aortogram. Elements such as the shape of the thickened aortic wall, ulcer-like intimal defects, and intimal calcification were examined. Changes in these elements were also examined on follow-up CT. DeBackey types 1 and 3 accounted for one and 14 cases, respectively. Initial precontrast CT demonstrated continuous, crescentic high attenuation areas along the wall of the descending aorta. In postcontrast scans, the crescentic areas were of relatively lower-attenuation and appeared along the aorta wall. Displaced intimal calcifications were seen in nine of fifteen patients. There was no intimal flap on all five aortogram, while aortic wall thickening and atherosclerotic change were demonstrated in four cases and in one case, respectively. Focal ulcers were seen in three cases. Ulcer-like intimal defects were demonstrated in a total of eleven cases (eight on CT, two on aortogram, and one on both). In ten of the twelve cases seen on follow up CT, the thickness of the intramural hematoma was seen to be reduced. Among the 15 cases, the operation was performed in two cases, and the remaining 13 received conservative treatment. In ten cases observed for more than twelve months, a recurrence of symptoms did not occur. Eccentric aortic wall thickening in patients who complain of acute chest pain is the result of acute aortic dissection with intramural hematoma, or a penetrating atherosclerotic ulcer of the aorta. The later may be differentiated from the former by the presence of on ulcer-like intimal defect. When both diseases are limited to the descending aorta, conservative treatment may

  4. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... is that those of us that do image-guided therapy depend on all these sophisticated ways of ... that we have when we do these image-guided therapies and treatment of stent graft. So I ...

  5. Novel Matricing Technique for Management of Fractured Cusp Conundrum – A Clinician’s Corner

    Science.gov (United States)

    Mittal, Priya Ramesh

    2016-01-01

    Longitudinal tooth fracture can be classified as craze lines, fractured cusp, cracked tooth, split tooth and vertical root fracture based on extent and severity of the fracture line. The most common type of longitudinal tooth fracture is fractured cusp that poses the treatment dilemma. Retention of the fractured cusp segment temporarily with matrix band followed by permanent bonded restoration and finally removal of tooth fragment during crown preparation is a novel technique. This paper throws light on a matricing and holding technique for the management of supra-crestally fractured palatal cusp of maxillary first premolar in a 29-year-old Asian male. PMID:27190970

  6. Tobacco smoking and aortic aneurysm

    DEFF Research Database (Denmark)

    Sode, Birgitte F; Nordestgaard, Børge G; Grønbæk, Morten;

    2012-01-01

    from the Copenhagen City Heart Study followed for up to 34years and in 56,211 individuals from the Copenhagen General Population Study followed for up to 7years. RESULTS: During follow-up, 335 and 169 individuals developed aortic aneurysm outcomes in the Copenhagen City Heart Study and Copenhagen...... General Population Study, respectively. According to the magnitude of the hazard ratios, tobacco consumption was the most important risk factor for hospitalization and death from aortic aneurysm, followed by male sex and hypertension in both cohorts. The population attributable risk of aortic aneurysm...... outcomes due to tobacco consumption was 64% and 47% in the Copenhagen City Heart Study and Copenhagen General Population Study, respectively, and ranked highest among population attributable risks of aortic aneurysm in both cohorts. The absolute 10-year risk for hospitalization or death from aortic...

  7. Similar fillings and isolation of cusps of hyperbolic 3-manifolds

    OpenAIRE

    Frigerio, R.

    2005-01-01

    In this paper we deepen the analysis of certain classes M_{g,k} of hyperbolic 3-manifolds that were introduced in a previous work by B. Martelli, C. Petronio and the author. Each element of M_{g,k} is an oriented complete finite-volume hyperbolic 3-manifold with compact connected geodesic boundary of genus g and k cusps. We study small deformations of the complete hyperbolic structure of manifolds in M_{g,k} via a close analysis of their geodesic triangulations. We prove that several elements...

  8. Dehn filling of cusped hyperbolic 3-manifolds with geodesic boundary

    OpenAIRE

    Frigerio, Roberto; Martelli, Bruno; Petronio, Carlo

    2003-01-01

    We define for each $g \\geq 2$ and $k \\geq 0$ a set $\\mathcal{M}_{g,k}$ of orientable hyperbolic 3-manifolds with $k$ toric cusps and a connected totally geodesic boundary of genus $g$. Manifolds in $\\mathcal{M}_{g,k}$ have Matveev complexity $g + k$ and Heegaard genus $g+1$, and their homology, volume, and Turaev-Viro invariants depend only on $g$ and $k$. In addition, they do not contain closed essential surfaces. The cardinality of $\\mathcal{M}_{g,k}$ for a fixed $k$ has grow...

  9. Anode current density distribution in a cusped field thruster

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Huan, E-mail: wuhuan58@qq.com; Liu, Hui, E-mail: hlying@gmail.com; Meng, Yingchao; Zhang, Junyou; Yang, Siyu; Hu, Peng; Chen, Pengbo; Yu, Daren [Mail Box 458, Harbin Institute of Technology (HIT), Harbin 150001 (China)

    2015-12-15

    The cusped field thruster is a new electric propulsion device that is expected to have a non-uniform radial current density at the anode. To further study the anode current density distribution, a multi-annulus anode is designed to directly measure the anode current density for the first time. The anode current density decreases sharply at larger radii; the magnitude of collected current density at the center is far higher compared with the outer annuli. The anode current density non-uniformity does not demonstrate a significant change with varying working conditions.

  10. Unusual Case of Overt Aortic Dissection Mimicking Aortic Intramural Hematoma.

    Science.gov (United States)

    Disha, Kushtrim; Kuntze, Thomas; Girdauskas, Evaldas

    2016-04-01

    We report an interesting case in which overt aortic dissection mimicked two episodes of aortic intramural hematoma (IMH) (Stanford A, DeBakey I). This took place over the course of four days and had a major influence on the surgical treatment strategy. The first episode of IMH regressed completely within 15 hours after it was clinically diagnosed and verified using imaging techniques. The recurrence of IMH was detected three days thereafter, resulting in an urgent surgical intervention. Overt aortic dissection with evidence of an intimal tear was diagnosed intraoperatively. PMID:27066437

  11. Reinforced aortic root reconstruction for acute type A aortic dissection involving the aortic root

    Directory of Open Access Journals (Sweden)

    Han Qing-qi

    2013-06-01

    Full Text Available OBJECTIVE: There are debates regarding the optimal approach for AAAD involving the aortic root. We described a modified reinforced aortic root reconstruction approach for treating AAAD involving the aortic root. METHODS: A total of 161 patients with AAAD involving the aortic root were treated by our modified reinforced aortic root reconstruction approach from January 1998 to December 2008. Key features of our modified approach were placement of an autologous pericardial patch in the false lumen, lining of the sinotubular junction lumen with a polyester vascular ring, and wrapping of the vessel with Teflon strips. Outcome measures included post-operative mortality, survival, complications, and level of aortic regurgitation. RESULTS: A total of 161 patients were included in the study (mean age: 43.3 1 15.5 years. The mean duration of follow-up was 5.1 1 2.96 years (2-12 years. A total of 10 (6.2% and 11 (6.8% patients died during hospitalization and during follow-up, respectively. Thirty-one (19.3% patients experienced postoperative complications. The 1-, 3-, 5-, and 10-year survival rates were 99.3%, 98%, 93.8%, and 75.5%, respectively. There were no instances of recurrent aortic dissection, aortic aneurysm, or pseudoaneurysm during the entire study period. The severity of aortic regurgitation dramatically decreased immediately after surgery (from 28.6% to 0% grade 3-4 and thereafter slightly increased (from 0% to 7.2% at 5 years and 9.1% at 10 years. CONCLUSION: This modified reinforced aortic root reconstruction was feasible, safe and durable/effective, as indicated by its low mortality, low postoperative complications and high survival rate.

  12. Annihilators for cusp forms of weight $2$ and level $4p^m$

    CERN Document Server

    Alvarez, Arturo

    2010-01-01

    We obtain operators, given essentially by formal sums of Hecke operators, that annihilate spaces of cusp forms of weight $2$ for $\\Gamma_1( p^m)\\cap \\Gamma(4)$, whose dimensions will be specified. Moreover, we obtain the principal part ($\\mathrm{mod} \\, p$), over the cusps, of certain meromorphic modular functions of level $4p^m$.

  13. In vitro repair of fractured fiber-reinforced cusp-replacing composite restorations

    NARCIS (Netherlands)

    Fennis, W.M.M.; Kreulen, C.M.; Tezvergil, A.; Lassila, L.V.; Vallittu, P.K.; Creugers, N.H.J.

    2011-01-01

    Objective. To assess fracture resistance and failure mode of repaired fiber-reinforced composite (FRC) cusp-replacing restorations. Methods. Sixteen extracted human premolars with fractured cusp-replacing woven (Group (A)) or unidirectional (Group (B)) FRC restorations from a previous loading experi

  14. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... see we've used the cautery to achieve access to the sternum. On the left hand side ... wound, which allows us to get more ready access to the aorta and the aortic valve. The ...

  15. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... to requiring surgery for aortic stenosis, left ventricular hypertrophy is a common manifestation. By that, I mean generally speaking any muscle that works harder in the body gets thicker ...

  16. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... symptoms and ultimately surgery may be in the future. The symptoms seen primarily with aortic stenosis at ... echocardiography is? Echocardiography is the use of ultrasound technology. Ultrasound technology is a form of the same ...

  17. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... thank you, Jim. This is obviously just a model of the heart just to give some perspective ... aortic repair, he would have had a cardiac evaluation prior to that and they probably would have ...

  18. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... for patients who would not tolerate well a traditional open operation or a less invasive operation, as ... physical reserve. So Barbara Bush recently had a traditional aortic valve replacement surgery. What makes a patient ...

  19. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... in severe aortic stenosis, as it's probably more stress than the patient's heart should have to undergo. ... There's been a lot of work done by academic cardiac surgeons and cardiologists to try to define ...

  20. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... other cardiovascular diseases including heart attack and increased risk of cardiovascular death. John, is there anything you ... with time. This highlights the mortality or the risk of death associated with aortic valve replacement and ...

  1. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... aortic stenosis and even tricuspid stenosis from rheumatic causes are much more common. To expand upon that ... out of the bloodstream and is thought to cause less untoward effects to the brain and other ...

  2. Minimally invasive aortic valve replacement

    DEFF Research Database (Denmark)

    Foghsgaard, Signe; Schmidt, Thomas Andersen; Kjaergard, Henrik K

    2009-01-01

    . The 30-day mortality rate for the 98 patients was zero, although 14 of the 98 mini-sternotomies had to be converted to complete sternotomies intraoperatively due to technical problems. Such conversion doubled the operative time over that of the planned full sternotomies. In the group of patients whose......In this descriptive prospective study, we evaluate the outcomes of surgery in 98 patients who were scheduled to undergo minimally invasive aortic valve replacement. These patients were compared with a group of 50 patients who underwent scheduled aortic valve replacement through a full sternotomy...... operations were completed as mini-sternotomies, 4 died later of noncardiac causes. The aortic cross-clamp and perfusion times were significantly different across all groups (P < 0.001), with the intended full-sternotomy group having the shortest times. In conclusion, the mini-aortic valve replacement is an...

  3. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... more likely we see aortic stenosis. Again, patient education is part of the evaluation and management of ... for patients who would not tolerate well a traditional open operation or a less invasive operation, as ...

  4. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... more likely we see aortic stenosis. Again, patient education is part of the evaluation and management of ... likely than patients who don't have other cardiovascular conditions: coronary artery disease, peripheral vascular disease, et ...

  5. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... in severe aortic stenosis, as it's probably more stress than the patient's heart should have to undergo. ... these series, when you critically look at the literature, the operative times can be significantly longer and ...

  6. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... to minimize their symptoms, but that doesn't impact the course of the disease itself. When I' ... more likely we see aortic stenosis. Again, patient education is part of the evaluation and management of ...

  7. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... starts out as a disease we call aortic sclerosis, which is the beginning of the process of ... path life. Again, it's a progressive disease from sclerosis, or the beginning of thickening of the valve, ...

  8. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... thank you, Jim. This is obviously just a model of the heart just to give some perspective ... the aorta at this point. 9 Earlier this month Robin Williams had his aortic valve replaced and ...

  9. Transcatheter Aortic Heart Valve Thrombosis

    DEFF Research Database (Denmark)

    Hansson, Nicolaj C; Grove, Erik L; Andersen, Henning R;

    2016-01-01

    BACKGROUND: There is increasing focus on transcatheter heart valve (THV) thrombosis. However, there are limited data on incidence, clinical implications and predisposing factors of THV thrombosis following transcatheter aortic valve replacement (TAVR). OBJECTIVES: We assessed the incidence...

  10. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... somebody for this operation. Again, there's no medical therapy that has been proven to slow or reverse ... to their physician. This may lead to earlier treatment and better outcomes as well. Aortic stenosis, as ...

  11. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... more likely we see aortic stenosis. Again, patient education is part of the evaluation and management of ... surgery we, as surgeons, know from our anatomy training during our course of training, we know where ...

  12. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... John, is there anything you can do to help prevent aortic stenosis? There's no prophylactic methods that ... very good looks. It's a great tool to help cardiac surgeons. Thanks, Jim. And I would underscore ...

  13. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... able to look at the aortic valve very well. In fact, transesophageal echocardiography is the best modality ... use to help evaluate both cardiac function as well as anatomy in patients who need heart surgery. ...

  14. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... a series of charts that we have, historical data, to know really what the best size is ... heart and lung circulation, so that we can open the aorta safely and replace this patient's aortic ...

  15. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... in severe aortic stenosis, as it's probably more stress than the patient's heart should have to undergo. ... in younger patients who want to return to work and activity more quickly, we feel that this ...

  16. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... uncommon to have more problems with their tissue quality and so we do have to be careful ... does not have an aortic aneurysm in the first part of their aorta there, their ascending aorta. ...

  17. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... No medications as such have been proven to slow that disease path life. Again, it's a progressive ... no medical therapy that has been proven to slow or reverse the process of aortic stenosis. Clearly, ...

  18. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... This process starts out as a disease we call aortic sclerosis, which is the beginning of the ... either tissues from cows or pigs, what we call porcine for pigs and bovine for cows. Essentially, ...

  19. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... including heart attack and increased risk of cardiovascular death. John, is there anything you can do to ... aortic stenosis, there's a pretty rapid progression into death if no intervention is taken. We feel that ...

  20. Reliability and Identification of Aortic Valve Prolapse in the Horse

    Directory of Open Access Journals (Sweden)

    Hallowell Gayle D

    2013-01-01

    Full Text Available Abstract Background The objectives were to determine and assess the reliability of criteria for identification of aortic valve prolapse (AVP using echocardiography in the horse. Results Opinion of equine cardiologists indicated that a long-axis view of the aortic valve (AoV was most commonly used for identification of AVP (46%; n=13. There was consensus that AVP could be mimicked by ultrasound probe malignment. This was confirmed in 7 healthy horses, where the appearance of AVP could be induced by malalignment. In a study of a further 8 healthy horses (5 with AVP examined daily for 5 days, by two echocardiographers standardized imaging guidelines gave good to excellent agreement for the assessment of AVP (kappa>0.80 and good agreement between days and observers (kappa >0.6. The technique allowed for assessment of the degree of prolapse and measurement of the prolapse distance that provided excellent agreement between echocardiographers, days and observers (kappa/ICC>0.8. Assessments made using real-time zoomed images provided similar measurements to the standard views (ICC=0.9, with agreement for the identification of AVP (kappa>0.8. Short axis views of the AoV were used for identification of AVP by fewer respondents (23%, however provided less agreement for the identification of AVP (kappa>0.6 and only adequate agreement with observations made in long axis (kappa>0.5, with AVP being identified more often in short axis (92% compared to long axis (76%. Orthogonal views were used by 31% of respondents to identify the presence of AVP, and 85% to identify cusp. Its identification on both views on 4 days was used to categorise horses as having AVP, providing a positive predictive value of 79% and negative predictive value of 18%. Only the non-coronary cusp (NCC of the AoV was observed to prolapse in these studies. Prolapse of the NCC was confirmed during the optimisation study using four-dimensional echocardiography, which concurred with the findings

  1. Plasma Structure and Behavior of Miniature Ring-Cusp Discharges

    Science.gov (United States)

    Mao, Hann-Shin

    Miniature ring-cusp ion thrusters provide a unique blend of high efficiencies and millinewton level thrust for future spacecraft. These thrusters are attractive as a primary propulsion for small satellites that require a high delta V, and as a secondary propulsion for larger spacecraft that require precision formation flying, disturbance rejection, or attitude control. To ensure desirable performance throughout the life of such missions, an advancement in the understanding of the plasma structure and behavior of miniature ring-cusp discharges is required. A research model was fabricated to provide a simplified experimental test bed for the analysis of the plasma discharge chamber of a miniature ion thruster. The plasma source allowed for spatially resolved measurements with a Langmuir probe along a meridian plane. Probe measurements yielded plasma density, electron temperature, and plasma potential data. The magnetic field strength was varied along with the discharge current to determine the plasma behavior under various conditions. The structure of the plasma properties were found to be independent of the discharge power under the proper scaling. It was concluded that weaker magnetic fields can improve the overall performance for ion thruster operation. To further analyze the experimental measurements, a framework was developed based on the magnetic field. A flux aligned coordinate system was developed to decouple the perpendicular and parallel plasma motion with respect to the magnetic field. This was done using the stream function and magnetic scalar potential. Magnetic formulae provided intuition on the field profiles dependence on magnet dimensions. The flux aligned coordinate system showed that the plasma was isopycnic along constant stream function values. This was used to develop an empirical relation suitable for estimating the spatial behavior and to determine the plasma volume and loss areas. The plasma geometry estimates were applied to a control volume

  2. Distribution in magnetotail of O+ ions from Cusp/Cleft ionosphere: A possible substorm trigger

    International Nuclear Information System (INIS)

    The transport of O+ ions from the cusp/cleft ionosphere to the magnetotail during highly disturbed times was determined by computing the guiding-center trajectories of the ions to a distance of 6 RE from the ionosphere and the full-motion trajectories at later times. Case histories were tallied in six planes perpendicular to the XGSM axis, three planes perpendicular to the YGSM axis, and in the center plane of the tail. At various times relatives to the enhancement of the convection electric field, the following ion properties were constructed from the case histories; number density, mean energy, energy and pitch angle distributions of the flux, and ion pressure components parallel and perpendicular to the magnetic field. It was found that after about 1.7 hours the ion flux in the near-Earth magnetotail increased dramatically and the spectrum hardened, much as observed during periods just preceding substorms. This increase is attributed to (1) the increase in the O+ outflux from the ionosphere, (2) the increased energization of the ions by the convection electric field, and (3) ion trapping, which generally occurs because the ion magnetic generally increase after the ions first cross the geomagnetotail center plane. Moreover, the parallel pressure of the ions exceeds the energy density of the magnetic field at XGSM E. On the basis of the expected alterations of the magnetic and electric fields in response to this O+ pressure, a substorm trigger mechanism is suggested

  3. CLUSTER encounters with the high altitude cusp: boundary structure and magnetic field depletions

    Directory of Open Access Journals (Sweden)

    P. J. Cargill

    2004-04-01

    Full Text Available Data from the four spacecraft Cluster mission during a high altitude cusp crossing on 13 February 2001 are presented. The spacecraft configuration has one leading spacecraft, with the three trailing spacecraft lying in a plane that corresponds roughly to the nominal magnetopause surface. The typical spacecraft separation is approximately 600km. The encounter occurs under conditions of strong and steady southward Interplanetary Magnetic Field (IMF. The cusp is identified as a seven-minute long depression in the magnetic field, associated with ion heating and a high abundance of He+. Cusp entry involves passage through a magnetopause boundary that has undergone very significant distortion from its nominal shape, is moving rapidly, and exhibits structure on scales of the order of the spacecraft separation or less. This boundary is associated with a rotation of the magnetic field, a normal field component, and a plasma flow into the cusp of approximately 35 km/s. However, it cannot be identified positively as a rotational discontinuity. Exit from the cusp into the lobe is through a boundary that is initially sharp, but then retreats tailward at a few km/s. As the leading spacecraft passes through this boundary, there is a plasma flow out of the cusp of approximately 30km/s, suggesting that this is not a tangential discontinuity. A few minutes after exit from the cusp, the three trailing the spacecraft see a single cusp-like signature in the magnetic field. There is an associated temperature increase at two of the three trailing spacecraft. Timing measurements indicate that this is due to cusp-like regions detaching from the rear of the cusp boundary, and moving tailward. The magnetic field in the cusp is highly disordered, with no obvious relation between the four spacecraft, indicative of structure on scales <<600km. However, the plasma moments show only a gradual change over many minutes. A similar cusp crossing on 20 February 2001 also

  4. Aortic Stent-Graft Infection Following Septic Complications of a Kidney Stone

    International Nuclear Information System (INIS)

    A 73-year-old man was treated because of a renal pelvis blowout of the left kidney for which he received a nephrostomy catheter without antibiotic prophylaxis. Almost a year previously this patient had undergone endovascular repair of a symptomatic infrarenal abdominal aorta aneurysm. Four weeks after the diagnosis and treatment of the ruptured renal pelvis, a new computed tomography scan and ultrasound-guided fine needle aspiration confirmed the diagnosis of infected aortic stent-graft. An extra-anatomic axillo-uniiliac bypass and graft excision was performed. Two weeks after discharge the patient returned to the hospital with an occlusion of his left renal artery and died of renal failure. This is the first time an infected aortic stent-graft after a renal pelvis blowout has been reported. Although infections of aortic stent-grafts occur rarely, one should be aware of the possibility in aortic stent-graft patients undergoing abdominal procedures without antibiotic prophylaxis

  5. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... information is critical for us in terms of planning and guiding the procedure we’re going to ... be screened. In fact, patients who have a family history of aneurysm, men who are smoking over ...

  6. Degeneracies of parametric lens model families near folds and cusps

    CERN Document Server

    Wagner, Jenny

    2015-01-01

    We develop an approach to select families of lens models that can describe doubly and triply gravitationally lensed images near folds and cusps using the model-independent ratios of lensing-potential derivatives derived in Wagner & Bartelmann (2015). Models are selected by comparing these model-independent ratios of potential derivatives to (numerically determined) ratios of potential derivatives along critical curves for entire lens model families in a given range of parameter values. This comparison returns parameter ranges which lens model families can reproduce observation within, as well as sections of the critical curve where image sets of the observed type can appear. If the model-independent potential-derivative ratios inferred from the observation fall outside the range of these ratios derived for the lens model family, the entire family can be excluded as a feasible model in the given volume in parameter space. We employ this approach for the family of singular isothermal spheres with external s...

  7. CUSP CATASTROPHE MODEL OF INSTABILITY OF PILLAR IN ASYMMETRIC MINING

    Institute of Scientific and Technical Information of China (English)

    LI Jiang-teng; CAO Ping

    2005-01-01

    A simplified mechanical model of pillar-hang wall was established in asymmetric mining and instability of the system was discussed by means of potential energy principle and cusp catastrophe theory. The necessary-sufficient condition and the jump value of displacement of pillar and the released energy expressions were derived,which established foundation for quantifying of the instability of system. The results show that instability of the system is related to load and its stiffness distribution. The critical load increases with the increasing relative stiffness, and the system is more stable. On the contrary, the instability of system is likely to occur, and the released energy is larger in instability process, and the harm is more tremendous accordingly.Furthermore, an example was calculated, and the estimated results are in good agreement with the practical experience, which provide basis for mining order and arranging stope.

  8. Hot electron confinement in a microwave heated spindle cusp

    International Nuclear Information System (INIS)

    The Plasma Research Laboratory at the University of Missouri-Columbia was established with awards from the McDonnel Douglas Foundation, ARMCO, Union Electric, Black and Vetch, Kansas City Power and Light, the National Science Foundation, and DOE. The Plasma Research Lab's major effort is the Missouri Magnetic Mirror (MMM or M3) Project. The technical goals of MMM have been (1) Diagnostic Development, (2) Plasma Physics in the Cusp geometry, (3) plasma-wall interactions, (4) impurity effects in a steady-state plasma, and (5) Development of Diagnostics for use in harsh plasma processing environments. The other major goal of MMM has remained providing a facility for hands-on training in experimental plasma physics. The major experimental facility of MMM is the MMM Modified Experiment (M4X). Other research efforts in the Plasma Research Laboratory include small efforts in cold fusion, toroidal magnetic confinement, and inertial confinement and a potentially major effort in direct conversion of nuclear energy

  9. Thrombelastography Guides Transfusion Strategy

    OpenAIRE

    Bay Nielsen, Henning

    2009-01-01

    During surgery for an abdominal aortic aneurysm, coagulation may be impaired and the use of thrombelastography (TEG) is described in six patients with a perioperative blood loss of 3L. During surgery blood products were infused but not platelets. When the patients were admitted to the intensive care unit, the TEG report demonstrated a lowered MA value indicating impaired function of platelets. The use of TEG may guide transfusion strategy.

  10. On the origin of the cusp in the transverse momentum distribution for the process of strong field ionization

    CERN Document Server

    Ivanov, I A

    2015-01-01

    We study the origin of the cusp-structure in the transverse or lateral electron momentum distribution (TEMD) for the process of tunelling ionization driven by a linearly polarized laser pulse. We show that appearance of the cusp in the TEMD can be explained as follows. Projection on the set of the Coulomb scattering states leads to appearance of "elementary" cusps which have simple structure as functions of the lateral momentum. This structure is independent of the detailed dynamics of the ionization process and can be described analytically. These "elementary" cusps can be used to describe the cusp-structure in TEMD.

  11. Cluster survey of the mid-altitude cusp – Part 2: Large-scale morphology

    Directory of Open Access Journals (Sweden)

    I. Dandouras

    2009-05-01

    Full Text Available In this second part of our statistical study of the mid-altitude cusp, we compare the cusp morphology, as seen in the Cluster ion spectrometer (CIS, to the interplanetary magnetic field (IMF orientation. We first recall the method we have used a to define the cusp properties, b to sort IMF conditions or behaviour in classes, c to determine the proper time delay between the solar wind monitors and Cluster. Then, we define a few morphological features of the cusp and we relate these to the prevailing IMF. Our results reveal, among other things, that the occurrence of clearly dispersed ion structures in the cusp is 48%. From these dispersions, we infer the distance to reconnection site, which we relate to external conditions. In all other cases, the cusp exhibits a more disturbed behaviour in terms of ion structures and fall in our "discontinuous" or "irregular" categories. Among these, a few interesting cases of discontinuous cusps occurring under stable IMF conditions have been identified. They all occur when the IMF is dominated by its Y-component, which plays in principle in favour of anti-parallel reconnection but their wide MLT and latitudinal distributions is a priori incompatible with the anti-parallel reconnection hypothesis solely.

  12. Auroral and magnetic variations in the polar cusp and cleft. Signatures of magnetopause boundary layer dynamics

    International Nuclear Information System (INIS)

    By combining continous ground-based observations of polar cleft/cusp auroras and local magnetic variations with electromagnetic parameters obtained from satellites in polar orbit (low-altitude cleft/cusp) and in the magnetosheath/interplanetary space, different electrodynamic processes in the polar cleft/cusp have been investigated. One of the more controversial questions in this field is related to the observed shifts in latitude of cleft/cusp auroras and the relationships with the interplanetary magnetic field (IMF) orientation, local magnetic disturbances (DP2 and DPY modes) and magnetospheric substorms. A new approach which may contribute to clarifying these complicated relationships, simultaneous groundbased observations of the midday and evening-midnight sectors of the auroral oval, is illustrated. A related topic is the spatial relationship between the cleft/cusp auroras and the ionospheric convection currents. A characteristic feature of the polar cusp and cleft regions during negative IMF Bz is repeated occurrence of certain short-lived auroral structures moving in accordance with the local convection pattern. Satellite measurements of particle precipitation, magnetic field and ion drift components permit detailed investigations of the electrodynamics of these cusp/cleft structures. Information on electric field components, Birkeland currents, Poynting flux, height-integrated Pedersen conductivity and Joule heat dissipation rate has been derived. These observations are discussed in relation to existing models of temporal plasma injections from the magnetosheath

  13. Bovine aortic arch: A novel association with thoracic aortic dilation

    International Nuclear Information System (INIS)

    Aim: To investigate whether there is a link between bovine arch and thoracic aortic aneurysm. Materials and methods: Computed tomography (CT) and magnetic resonance imaging (MRI) images of the thorax of 191 patients with dilated thoracic aortas and 391 consecutive, unselected patients as controls were retrospectively reviewed. Bovine arch was considered present if either a shared origin of the left common carotid and innominate arteries or an origin of the left common carotid from the innominate artery was identified. A chi-square test was used to evaluate the significance of differences between subgroups. Results: A trend towards increased prevalence of bovine arch was seen in patients with dilated aortas (26.2%) compared to controls (20.5%, p = 0.12). The association was statistically significant in patients over 70 years old (31.9%, p = 0.019) and when dilation involved the aortic arch (47.6%, p = 0.003). Conclusions: An association between bovine arch and aortic dilation is seen in older patients, and when dilation involves the aortic arch. Bovine arch should be considered a potential risk factor for thoracic aortic aneurysm.

  14. Endoluminal treatment of aortic dissection

    Energy Technology Data Exchange (ETDEWEB)

    Chavan, Ajay; Lotz, Joachim; Galanski, Michael [Department of Diagnostic Radiology, Hannover Medical School, Carl Neuberg Strasse 1, 30625, Hannover (Germany); Oelert, Frank; Haverich, Axel; Karck, Matthias [Department of Thoracic and Cardiovascular Surgery, Hannover Medical School, Carl Neuberg Strasse 1, 30625, Hannover (Germany)

    2003-11-01

    Aortic dissection is most often a catastrophic medical emergency which, if untreated, can be potentially fatal. The intention of therapy in patients with aortic dissection is to prevent aortic rupture or aneurysm formation as well as to relieve branch vessel ischaemia. Patients with aortic dissection are often poor candidates for anaesthesia and surgery and the surgical procedure itself is challenging requiring thoracotomy, aortic cross clamping, blood transfusion as well as prolonged hospital stay in some cases. Operative mortality is especially high in patients with critical mesenteric or renal ischaemia. The past decade has experienced the emergence of a number of interventional radiological or minimally invasive techniques which have significantly improved the management of patients with aortic dissection. These include stent grafting for entry site closure to prevent aneurysmatic widening of the false lumen as well as percutaneous techniques such as balloon fenestration of the intimal flap and aortic true lumen stenting to alleviate branch vessel ischaemia. False lumen thrombosis following entry closure with stent grafts has been observed in 86-100% of patients, whereas percutaneous interventions are able to effectively relieve organ ischaemia in approximately 90% of the cases. In the years to come, it is to be expected that these endoluminal techniques will become the method of choice for treating most type-B dissections and will assist in significantly reducing the number of open surgical procedures required for type-A dissections. The intention of this article is to provide an overview of the current status of these endoluminal techniques based on our own experience as well as on a review of the relevant literature. (orig.)

  15. Endoluminal treatment of aortic dissection

    International Nuclear Information System (INIS)

    Aortic dissection is most often a catastrophic medical emergency which, if untreated, can be potentially fatal. The intention of therapy in patients with aortic dissection is to prevent aortic rupture or aneurysm formation as well as to relieve branch vessel ischaemia. Patients with aortic dissection are often poor candidates for anaesthesia and surgery and the surgical procedure itself is challenging requiring thoracotomy, aortic cross clamping, blood transfusion as well as prolonged hospital stay in some cases. Operative mortality is especially high in patients with critical mesenteric or renal ischaemia. The past decade has experienced the emergence of a number of interventional radiological or minimally invasive techniques which have significantly improved the management of patients with aortic dissection. These include stent grafting for entry site closure to prevent aneurysmatic widening of the false lumen as well as percutaneous techniques such as balloon fenestration of the intimal flap and aortic true lumen stenting to alleviate branch vessel ischaemia. False lumen thrombosis following entry closure with stent grafts has been observed in 86-100% of patients, whereas percutaneous interventions are able to effectively relieve organ ischaemia in approximately 90% of the cases. In the years to come, it is to be expected that these endoluminal techniques will become the method of choice for treating most type-B dissections and will assist in significantly reducing the number of open surgical procedures required for type-A dissections. The intention of this article is to provide an overview of the current status of these endoluminal techniques based on our own experience as well as on a review of the relevant literature. (orig.)

  16. Talon cusp: A case report with management guidelines for practicing dentists

    Directory of Open Access Journals (Sweden)

    Reecha Gupta

    2013-01-01

    Full Text Available Introduction: Talon cusp is an uncommon odontogenic anomaly which most frequently affects maxillary permanent incisors. Its presence causes the problem in esthetics, prevention of caries, and occlusal accommodation for the patient and problems in the diagnosis and clinical management for the dentist. Case Report: This article reports a case of talon cusp on the palatal surface of the permanent maxillary central incisor. Discussion: Since, the presence of talon cusp usually demands that definitive treatment be instituted; it represents a problem of clinical significance. The dentist should be able to diagnose it as the maxillary incisor is also the principal site for supernumerary tooth.

  17. Gravitational-Wave Stochastic Background from Kinks and Cusps on Cosmic Strings

    OpenAIRE

    Olmez, S.; Mandic, V.; Siemens, X.

    2010-01-01

    We compute the contribution of kinks on cosmic string loops to stochastic background of gravitational waves (SBGW).We find that kinks contribute at the same order as cusps to the SBGW.We discuss the accessibility of the total background due to kinks as well as cusps to current and planned gravitational wave detectors, as well as to the big bang nucleosynthesis (BBN), the cosmic microwave background (CMB), and pulsar timing constraints. As in the case of cusps, we find that current data from i...

  18. Gravitational-Wave Stochastic Background from Kinks and Cusps on Cosmic Strings

    CERN Document Server

    Olmez, S; Siemens, X

    2010-01-01

    We compute the contribution of kinks on cosmic string loops to stochastic background of gravitational waves (SBGW).We find that kinks contribute at the same order as cusps to the SBGW.We discuss the accessibility of the total background due to kinks as well as cusps to current and planned gravitational wave detectors, as well as to the big bang nucleosynthesis (BBN), the cosmic microwave background (CMB), and pulsar timing constraints. As in the case of cusps, we find that current data from interferometric gravitational wave detectors, such as LIGO, are sensitive to areas of parameter space of cosmic string models complementary to those accessible to pulsar, BBN, and CMB bounds.

  19. Singular Curves in the Joint Space and Cusp Points of 3-RPR parallel manipulators

    CERN Document Server

    Zein, Mazen; Chablat, Damien

    2007-01-01

    This paper investigates the singular curves in the joint space of a family of planar parallel manipulators. It focuses on special points, referred to as cusp points, which may appear on these curves. Cusp points play an important role in the kinematic behavior of parallel manipulators since they make possible a nonsingular change of assembly mode. The purpose of this study is twofold. First, it exposes a method to compute joint space singular curves of 3-RPR planar parallel manipulators. Second, it presents an algorithm for detecting and computing all cusp points in the joint space of these same manipulators.

  20. Catastrophe mechanism and classification of discontinuity behavior in thermal science (Ⅱ) -- Cusp catastrophe

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The catastrophe mechanisms of thermal performance characteristics of the firebox gas combustion system were analyzed from the viewpoint of catastrophe theory. The mathematical models of cusp catastrophe were established. The relationship between the thermal performance characteristics and the changing of system control variables was studied. The cusp catastrophe mechanisms of typical performance characteristics, such as kicking and lagging, and those of transition from quenching to igniting were explained. It was illustrated that discontinuity behavior of thermal systems with an "S" motion feature curve and lagging feature may be equivalently classified according to the topology of cusp catastrophe, influenced by two groups of independent control variables.

  1. Numerical Prediction of cusps or kinks in the Nambu-Goto dynamics

    CERN Document Server

    Cervantes, Aldrin

    2014-01-01

    It is known that Nambu-Goto world-sheet present some pathological structures, such as cusps and kinks, during its evolution. We propose a method through the Raychaudhuri equation for membranes to determine if there are cusps and kinks in the world-sheet. We generalize the Raychaudhuri equation for non-extremal membranes and use it as a tool for determining when a string in the Nambu-Goto action will form cusps or kinks in its evolution. Furthermore, we present two examples where we test graphically this method.

  2. Acute aortic valve prolapse in Marfan's syndrome.

    OpenAIRE

    Carr, N J; Cullen, S. A.

    1991-01-01

    A 22 year old man with Marfan's syndrome died suddenly following acute aortic valve prolapse. Although aortic root involvement in Marfan's syndrome is common, we have found no previous description of this particular complication in the literature.

  3. Aortic valve replacement through right thoracotomy.

    OpenAIRE

    Rao, P N; A S Kumar

    1993-01-01

    There has never, to our knowledge, been a report of aortic valve replacement via a right thoracotomy. However, we recently used this approach in 2 young women with severe aortic stenosis. Exposure of the aortic valve was excellent, and we encountered neither technical difficulties nor sequelae related to the right thoracotomy. We believe that right thoracotomy provides adequate access for safe aortic valve replacement and yields cosmetically more appealing results than does median sternotomy.

  4. ABDOMINAL AORTIC ANEURYSM (AAA

    Directory of Open Access Journals (Sweden)

    Rajesh G

    2011-11-01

    Full Text Available AAA is defined as a distension of the infrarenal aorta by more than 50% (or 1.5 times compared with a corresponding healthy, aged and gender matched population. AAA afflicts 1 to 6 % of the general population aged more than 60 years and the incidence rises by approximately 0.15% annually. When the definition of a maximum external diameter ≥3 cm is used, the prevalence of AAA is upto 6 times greater in men than in women. AAAs are much more common than thoracic aortic aneurysms. Most common cause of AAA is atherosclerosis (95%. Less common causes include infectious or inflammatory origin or those associated with connective tissue disorders. Process of AAA formation is multifactorial. Other than the general risk factors for atherosclerosis, genetic predispo s iti on, aut o immunity and hemodynamic factors all play roles in its formation. AAA is 1.5 times more frequent in hypert ensive patients. Smokers have 8 times risk for developing AAA. The existence of familial aggre gation of AAA implicates genetic factors in the etiology of AAA. Women with AAA are more likely to have a positive family history of this disorder. Those with a family history of AAA have an increased risk of 30%, and their aneurysms tend to occur at a younger age and carry a greater risk of rupture than do sporadic aneurysms.

  5. Resolution of an Acute Aortic Syndrome with Aortic Valve Insufficiency Post-PCI

    OpenAIRE

    de Barros e Silva, Pedro G.M.; Aquino, Thiago de; Resende, Marcos V.; Richter, Ivo; Barros, Cecilia M.; Andrioli, Vanessa G.; Baruzzi, Antonio C.; Medeiros, Caio C.J.; Furlan, Valter

    2014-01-01

    Patient: Female, 52 Final Diagnosis: Acute aortic syndrome with aortic valve insufficiency post-PCI Symptoms: Chest pain Medication: — Clinical Procedure: Conservative Specialty: Cardiology Objective: Unusual or unexpected effect of treatment Background: Acute aortic syndrome is the modern term that includes aortic dissection, intramural hematoma, and symptomatic aortic ulcer. Iatrogenic coronary artery dissection extending to the aorta during percutaneous coronary intervention is a very rare...

  6. Stroke in Patients With Aortic Stenosis

    DEFF Research Database (Denmark)

    Greve, Anders Møller; Dalsgaard, Morten; Bang, Casper N;

    2014-01-01

    BACKGROUND AND PURPOSE: There are limited data on risk stratification of stroke in aortic stenosis. This study examined predictors of stroke in aortic stenosis, the prognostic implications of stroke, and how aortic valve replacement (AVR) with or without concomitant coronary artery bypass graftin...... associated with mortality. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00092677....

  7. Persistent Fifth Aortic Arch with Coarctation

    Science.gov (United States)

    Kim, Sue Hyun; Choi, Eun-Suk; Cho, Sungkyu; Kim, Woong-Han

    2016-01-01

    Persistent fifth aortic arch (PFAA) is a rare congenital anomaly of the aortic arch frequently associated with other cardiovascular anomalies, such as tetralogy of Fallot and aortic arch coarctation or interruption. We report the case of a neonate with PFAA with coarctation who successfully underwent surgical repair. PMID:26889445

  8. Singular curves and cusp points in the joint space of 3-RPR parallel manipulators

    CERN Document Server

    Zein, Mazen; Chablat, Damien

    2006-01-01

    This paper investigates the singular curves in two-dimensional slices of the joint space of a family of planar parallel manipulators. It focuses on special points, referred to as cusp points, which may appear on these curves. Cusp points play an important role in the kinematic behavior of parallel manipulators since they make possible a nonsingular change of assembly mode. The purpose of this study is twofold. First, it reviews an important previous work, which, to the authors' knowledge, has never been exploited yet. Second, it determines the cusp points in any two-dimensional slice of the joint space. First results show that the number of cusp points may vary from zero to eight. This work finds applications in both design and trajectory planning.

  9. [MINIMALLY INVASIVE AORTIC VALVE REPLACEMENT].

    Science.gov (United States)

    Tabata, Minoru

    2016-03-01

    Minimally invasive aortic valve replacement (MIAVR) is defined as aortic valve replacement avoiding full sternotomy. Common approaches include a partial sternotomy right thoracotomy, and a parasternal approach. MIAVR has been shown to have advantages over conventional AVR such as shorter length of stay and smaller amount of blood transfusion and better cosmesis. However, it is also known to have disadvantages such as longer cardiopulmonary bypass and aortic cross-clamp times and potential complications related to peripheral cannulation. Appropriate patient selection is very important. Since the procedure is more complex than conventional AVR, more intensive teamwork in the operating room is essential. Additionally, a team approach during postoperative management is critical to maximize the benefits of MIAVR. PMID:27295772

  10. Cluster survey of the mid-altitude cusp: 1. size, location, and dynamics

    Directory of Open Access Journals (Sweden)

    F. Pitout

    2006-11-01

    Full Text Available We present a statistical study of four years of Cluster crossings of the mid-altitude cusp. In this first part of the study, we start by introducing the method we have used a to define the cusp properties, b to sort the interplanetary magnetic field (IMF conditions or behaviors into classes, c to determine the proper time delay between the solar wind monitors and Cluster. Out of the 920 passes that we have analyzed, only 261 fulfill our criteria and are considered as cusp crossings. We look at the size, location and dynamics of the mid-altitude cusp under various IMF orientations and solar wind conditions. For southward IMF, Bz rules the latitudinal dynamics, whereas By governs the zonal dynamics, confirming previous works. We show that when |By| is larger than |Bz|, the cusp widens and its location decorrelates from By. We interpret this feature in terms of component reconnection occurring under By-dominated IMF. For northward IMF, we demonstrate that the location of the cusp depends primarily upon the solar wind dynamic pressure and upon the Y-component of the IMF. Also, the multipoint capability of Cluster allows us to conclude that the cusp needs typically more than ~20 min to fully adjust its location and size in response to changes in external conditions, and its speed is correlated to variations in the amplitude of IMF-Bz. Indeed, the velocity in °ILAT/min of the cusp appears to be proportional to the variation in Bz in nT: Vcusp=0.024 ΔBz. Finally, we observe differences in the behavior of the cusp in the two hemispheres. Those differences suggest that the cusp moves and widens more freely in the summer hemisphere.

  11. Cusp observation at Saturn's high-latitude magnetosphere by the Cassini spacecraft

    OpenAIRE

    Jasinski, J. M.; Arridge, C.S.; Lamy, L; J. S. Leisner; M. F. Thomsen; Mitchell, Donald G; Coates, A. J.; Radioti, A.; Jones, Geraint H.; Roussos, E; Krupp, N.; Grodent, D.; Dougherty, M. K.; Waite, J. H.

    2014-01-01

    We report on the first analysis of magnetospheric cusp observations at Saturn by multiple in situ instruments onboard the Cassini spacecraft. Using this we infer the process of reconnection was occurring at Saturn's magnetopause. This agrees with remote observations that showed the associated auroral signatures of reconnection. Cassini crossed the northern cusp around noon local time along a poleward trajectory. The spacecraft observed ion energy-latitude dispersionsa characteristic signature...

  12. Quasistatic electric field structures and field-aligned currents in the polar cusp region

    Science.gov (United States)

    Jacobsen, K. S.; Moen, J. I.; Pedersen, A.

    2010-10-01

    Cluster data have been examined for quasi-stationary electric field structures and field-aligned currents (FACs) in the vicinity of the dayside cusp region. We have related the measurements to the Region 1/Region 2 (R1/R2) current system and the cusp current system. It has been theoretically proposed that the dayside R1 current may be located on open field lines, and experimental evidence has been shown for R1 currents partially on open field lines. We document that R1 currents may flow entirely on open field lines. The electric field structures are found to occur at plasma density gradients in the cusp. They are associated with strong FACs with current directions that are consistent with the cusp currents. This indicates that the electric field structures are closely coupled to the cusp current system. The electric equipotential structures linking the perpendicular electric fields seen at Cluster altitudes to field-aligned electric fields at lower altitudes fall into one of two categories: S shape or U shape. Both types are found at both the equatorward edge of the cusp ion dispersion and at the equatorward edge of injection events within the cusp. Previous studies in the nightside auroral region attributed the S-shaped potential structures to the boundary transition between the low-density polar cap and the high-density plasma sheet, concluding that the shape of the electric potential structure depends on whether the plasma populations on each side of the structure can support intense currents. This explanation is not applicable for the S-shaped structures observed in the dayside cusp region.

  13. Transport coefficients for laminar and turbulent flow through a four-cusp channel

    International Nuclear Information System (INIS)

    The heat transfer coefficients for laminar and turbulent flow in a four-cusp channel were determined. A numerical solution was developed for laminar flow an and experimental study for turbulent flow was carried out. Systematic variations of the Reynolds number were done in the range 900-30000. The results show that the heat transfer coefficients for the four-cusp channel are much lower than the coefficients for the circular tube. (author)

  14. Aortic Impedance in Little Mice

    OpenAIRE

    Reddy, Anilkumar K.; Taffet, George E.; Hartley, Craig J.

    2008-01-01

    The Little dwarf mouse lives 30% longer than its age-matched wild-type (WT) mouse. We determined aortic input impedance in 21 (8 Little, 13 WT) 4 month-old mice. Modulus of impedance was calculated from the Fourier transformed aortic pressure (P) and average luminal flow velocity (Vavg) as ∣Zi∣ = ∣P∣/∣Vavg∣. Characteristic impedance was estimated by averaging the 2nd-10th harmonic of the impedance moduli. We found the impedance modulus ∣Zi∣ to be similar in the 2 groups (WT vs. Little; mean±S...

  15. Treatment of an Aortic Traumatic Double Rupture

    Directory of Open Access Journals (Sweden)

    Attinà Domenico

    2015-03-01

    Full Text Available Traumatic thoracic aortic rupture is a life-threatening condition; aortic isthmus is the most common site of rupture, but in rare cases traumatic injury can localize elsewhere, such as at aortic arch or at the level of the diaphragm. In the past few years, endovascular treatment of traumatic aortic injury became a safe procedure, with lower mortality and complication, if compared with open surgery. We report a case of a 40-year-old-man admitted to emergency department after a violent car crash in which an aortic traumatic double rupture was successfully treated with two endovascular stent-grafts coverage.

  16. Hydatid cyst involving the aortic arch.

    Science.gov (United States)

    Apaydin, Anil Z; Oguz, Emrah; Zoghi, Mehdi

    2007-03-01

    We report a very rare case of primary mediastinal hydatid cyst which invaded the ascending aorta and the aortic arch which initially presented as a cranial mass. Aortic wall is a very unusual site for the hydatid cysts. To the best of our knowledge, this is the first reported case of hydatid cyst located within the aortic arch lumen. Patient underwent ascending aortic and hemiarch replacement under hypothermic circulatory arrest and removal of the cyst. Patient had an uneventful recovery and has been on follow-up. Although the literature data are very limited, we believe that the aortic procedure of choice should be graft interpositon rather than patch repair. PMID:17215134

  17. The three-loop cusp anomalous dimension in QCD and its supersymmetric extensions

    Science.gov (United States)

    Grozin, Andrey G.; Henn, Johannes M.; Korchemsky, Gregory P.; Marquard, Peter

    2016-01-01

    We present the details of the analytic calculation of the three-loop angle-dependent cusp anomalous dimension in QCD and its supersymmetric extensions, including the maximally supersymmetric N=4 super Yang-Mills theory. The three-loop result in the latter theory is new and confirms a conjecture made in our previous paper. We study various physical limits of the cusp anomalous dimension and discuss its relation to the quark-antiquark potential including the effects of broken conformal symmetry in QCD. We find that the cusp anomalous dimension viewed as a function of the cusp angle and the new effective coupling given by light-like cusp anomalous dimension reveals a remarkable universality property — it takes the same form in QCD and its supersymmetric extensions, to three loops at least. We exploit this universality property and make use of the known result for the three-loop quark-antiquark potential to predict the special class of nonplanar corrections to the cusp anomalous dimensions at four loops. Finally, we also discuss in detail the computation of all necessary Wilson line integrals up to three loops using the method of leading singularities and differential equations.

  18. The three-loop cusp anomalous dimension in QCD and its supersymmetric extensions

    Energy Technology Data Exchange (ETDEWEB)

    Grozin, Andrey G. [SB RAS, Novosibirsk (Russian Federation). Budker Intitute for Nuclear Physics; Novosibirsk State Univ. (Russian Federation); Henn, Johannes M. [Mainz Univ. (Germany). PRISMA Cluster of Excellence; Korchemsky, Gregory P. [CEA Saclay, Gif-sur-Yvette (France). Inst. de Physique Theorique; Marquard, Peter [DESY Zeuthen (Germany)

    2015-11-15

    We present the details of the analytic calculation of the three-loop angledependent cusp anomalous dimension in QCD and its supersymmetric extensions, including the maximally supersymmetric N=4 super Yang-Mills theory. The three-loop result in the latter theory is new and confirms a conjecture made in our previous paper. We study various physical limits of the cusp anomalous dimension and discuss its relation to the quark-antiquark potential including the effects of broken conformal symmetry in QCD. We find that the cusp anomalous dimension viewed as a function of the cusp angle and the new effective coupling given by light-like cusp anomalous dimension reveals a remarkable universality property - it takes the same form in QCD and its supersymmetric extensions, to three loops at least. We exploit this universality property and make use of the known result for the three-loop quark-antiquark potential to predict the special class of nonplanar corrections to the cusp anomalous dimensions at four loops. Finally, we also discuss in detail the computation of all necessary Wilson line integrals up to three loops using the method of leading singularities and differential equations.

  19. The three-loop cusp anomalous dimension in QCD and its supersymmetric extensions

    International Nuclear Information System (INIS)

    We present the details of the analytic calculation of the three-loop angledependent cusp anomalous dimension in QCD and its supersymmetric extensions, including the maximally supersymmetric N=4 super Yang-Mills theory. The three-loop result in the latter theory is new and confirms a conjecture made in our previous paper. We study various physical limits of the cusp anomalous dimension and discuss its relation to the quark-antiquark potential including the effects of broken conformal symmetry in QCD. We find that the cusp anomalous dimension viewed as a function of the cusp angle and the new effective coupling given by light-like cusp anomalous dimension reveals a remarkable universality property - it takes the same form in QCD and its supersymmetric extensions, to three loops at least. We exploit this universality property and make use of the known result for the three-loop quark-antiquark potential to predict the special class of nonplanar corrections to the cusp anomalous dimensions at four loops. Finally, we also discuss in detail the computation of all necessary Wilson line integrals up to three loops using the method of leading singularities and differential equations.

  20. The three-loop cusp anomalous dimension in QCD and its supersymmetric extensions

    CERN Document Server

    Grozin, Andrey; Korchemsky, Gregory P; Marquard, Peter

    2015-01-01

    We present the details of the analytic calculation of the three-loop angle-dependent cusp anomalous dimension in QCD and its supersymmetric extensions, including the maximally supersymmetric $\\mathcal{N}=4$ super Yang-Mills theory. The three-loop result in the latter theory is new and confirms a conjecture made in our previous paper. We study various physical limits of the cusp anomalous dimension and discuss its relation to the quark-antiquark potential including the effects of broken conformal symmetry in QCD. We find that the cusp anomalous dimension viewed as a function of the cusp angle and the new effective coupling given by light-like cusp anomalous dimension reveals a remarkable universality property -- it takes the same form in QCD and its supersymmetric extensions, to three loops at least. We exploit this universality property and make use of the known result for the three-loop quark-antiquark potential to predict the special class of nonplanar corrections to the cusp anomalous dimensions at four lo...

  1. Design of a cusped field thruster for drag-free flight

    Science.gov (United States)

    Liu, H.; Chen, P. B.; Sun, Q. Q.; Hu, P.; Meng, Y. C.; Mao, W.; Yu, D. R.

    2016-09-01

    Drag-free flight has played a more and more important role in many space missions. The thrust control system is the key unit to achieve drag-free flight by providing a precise compensation for the disturbing force except gravity. The cusped field thruster has shown a significant potential to be capable of the function due to its long life, high efficiency, and simplicity. This paper demonstrates a cusped field thruster's feasibility in drag-free flight based on its instinctive characteristics and describes a detailed design of a cusped field thruster made by Harbin Institute of Technology (HIT). Furthermore, the performance test is conducted, which shows that the cusped field thruster can achieve a continuously variable thrust from 1 to 20 mN with a low noise and high resolution below 650 W, and the specific impulse can achieve 1800 s under a thrust of 18 mN and discharge voltage of 1000 V. The thruster's overall performance indicates that the cusped field thruster is quite capable of achieving drag-free flight. With the further optimization, the cusped field thruster will exhibit a more extensive application value.

  2. Using The Descending Aortic Wall Thickness Measured In Transesophageal Echocardiography As A Risk Marker For Aortic Dissection

    OpenAIRE

    Zaher Fanari; Sumaya Hammami; Muhammad Baraa Hammami; Safa Hammami; Chete Eze-Nliam; Weintraub, William S.

    2015-01-01

    Objective: The aim of this study is to estimate whether aortic wall thickness is increased in patients with Aortic dissection (AD) compared to low risk control group and can be used in addition to aortic diameter as a risk marker of AD. Background: AD occurs due to pathologies that may increase thickness of the aortic wall. Transesophageal echocardiography (TEE) has the ability to visualise both the thoracic aortic wall and lumen. Aortic diameter has been used to predict aortic dissection...

  3. Electrostatic acceleration of helicon plasma using a cusped magnetic field

    International Nuclear Information System (INIS)

    The electrostatic acceleration of helicon plasma is investigated using an electrostatic potential exerted between the ring anode at the helicon source exit and an off-axis hollow cathode in the downstream region. In the downstream region, the magnetic field for the helicon source, which is generated by a solenoid coil, is modified using permanent magnets and a yoke, forming an almost magnetic field-free region surrounded by an annular cusp field. Using a retarding potential analyzer, two primary ion energy peaks, where the lower peak corresponds to the space potential and the higher one to the ion beam, are detected in the field-free region. Using argon as the working gas with a helicon power of 1.5 kW and a mass flow rate of 0.21 mg/s, the ion beam energy is on the order of the applied acceleration voltage. In particular, with an acceleration voltage lower than 150 V, the ion beam energy even exceeds the applied acceleration voltage by an amount on the order of the electron thermal energy at the exit of the helicon plasma source. The ion beam energy profile strongly depends on the helicon power and the applied acceleration voltage. Since by this method the whole working gas from the helicon plasma source can, in principle, be accelerated, this device can be applied as a noble electrostatic thruster for space propulsion

  4. A cusped field H- ion source for LAMPF

    International Nuclear Information System (INIS)

    The addition of the Proton Storage Ring (PSR) to LAMPF requires the development of a more intense H- ion source. The goals of this development program are to produce a beam of sufficient quality to match the acceptance of the accelerator and of sufficient intensity and duty factor to satisfy PSR operation as well as existing LAMPF requirements. The ion source concept best suited to these demands is the multi-cusp negative ion source being developed at LBL. The H- ion source development was carried out on the high-voltage test stand in the LAMPF injector complex. The test stand, upgraded for the project, provides both unanalyzed and mass-analyzed beams to appropriate emittance scanning stations. Beam currents are measured using both beam current toroids and biased Faraday cups in both sections of the transport line. The emittance data are processed by the SEL 840 control computer at LAMPF. Ion source testing has been carried out using the extraction optics originally developed for the LAMPF duoplasmatron. Optics questions are being addressed by the plasma simulation code SNOW developed at Sandia. The accelerating column design will seek to minimize the divergence of the extracted beam and the predictions from SNOW will be tested on the stand with actual H- beams

  5. Axion dark matter, solitons, and the cusp-core problem

    CERN Document Server

    Marsh, David J E

    2015-01-01

    Self-gravitating bosonic fields can support stable and localised field configurations. For real fields, these solutions oscillate in time and are known as oscillatons. The density profile is static, and is soliton. Such solitons should be ubiquitous in models of axion dark matter, with the soliton characteristic mass and size depending on some inverse power of the axion mass. Stable configurations of non-relativistic axions are studied numerically using the Schr\\"{o}dinger-Poisson system. This method, and the resulting soliton density profiles, are reviewed. Using a scaling symmetry and the uncertainty principle, the core size of the soliton can be related to the central density and axion mass, $m_a$, in a universal way. Solitons have a constant central density due to pressure-support, unlike the cuspy profile of cold dark matter (CDM). One consequence of this fact is that solitons composed of ultra-light axions (ULAs) may resolve the `cusp-core' problem of CDM. In DM halos, thermodynamics will lead to a CDM-...

  6. Spectrum of Aortic Valve Abnormalities Associated with Aortic Dilation Across Age Groups in Turner Syndrome

    Science.gov (United States)

    Olivieri, Laura J.; Baba, Ridhwan Y.; Arai, Andrew E.; Bandettini, W. Patricia; Rosing, Douglas R.; Bakalov, Vladimir; Sachdev, Vandana; Bondy, Carolyn A.

    2014-01-01

    Background Congenital aortic valve fusion is associated with aortic dilation, aneurysm and rupture in girls and women with Turner syndrome (TS). Our objective was to characterize aortic valve structure in subjects with TS, and determine the prevalence of aortic dilation and valve dysfunction associated with different types of aortic valves. Methods and Results The aortic valve and thoracic aorta were characterized by cardiovascular magnetic resonance imaging in 208 subjects with TS in an IRB-approved natural history study. Echocardiography was used to measure peak velocities across the aortic valve, and the degree of aortic regurgitation. Four distinct valve morphologies were identified: tricuspid aortic valve (TAV) 64%(n=133), partially fused aortic valve (PF) 12%(n=25), bicuspid aortic valve (BAV) 23%(n=47), and unicuspid aortic valve (UAV) 1%(n=3). Age and body surface area (BSA) were similar in the 4 valve morphology groups. There was a significant trend, independent of age, towards larger BSA-indexed ascending aortic diameters (AADi) with increasing valve fusion. AADi were (mean +/− SD) 16.9 +/− 3.3 mm/m2, 18.3 +/− 3.3 mm/m2, and 19.8 +/− 3.9 mm/m2 (p<0.0001) for TAV, PF and BAV+UAV respectively. PF, BAV, and UAV were significantly associated with mild aortic regurgitation and elevated peak velocities across the aortic valve. Conclusions Aortic valve abnormalities in TS occur with a spectrum of severity, and are associated with aortic root dilation across age groups. Partial fusion of the aortic valve, traditionally regarded as an acquired valve problem, had an equal age distribution and was associated with an increased AADi. PMID:24084490

  7. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... more likely we see aortic stenosis. Again, patient education is part of the evaluation and management of ... want to embrace less invasive or more progressive technology, you want to make ... with that information and certainly shouldn't be insulted by that. ...

  8. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... well. I want to underscore again that exercise testing is really not recommended in patient with classic symptoms in severe aortic stenosis, as it's probably more stress than the patient's heart should have to undergo. Once again, serial evaluations, as with any chronic disease process, are ...

  9. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... or in most patients who come to requiring surgery for aortic stenosis, left ventricular hypertrophy is a common manifestation. By that, I mean generally speaking any muscle that works harder in the body gets thicker and bigger over time and that's ...

  10. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... county more likely we see aortic stenosis. Again, patient education is part of the evaluation and management of valvular disease prior to surgery is paramount. It's important for a patient to understand really with any chronic condition what ...

  11. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... valve in the aortic position will grow over time and proves a nice replacement. However, that's sort of operating on two valves to fix one valvular problem. And for most patients in our practice in their 50s, 60s, et cetera, we tend ...

  12. Evolution of M1 crown size and cusp proportions in the genus Homo.

    Science.gov (United States)

    Quam, Rolf; Bailey, Shara; Wood, Bernard

    2009-05-01

    Previous research into tooth crown dimensions and cusp proportions has proved to be a useful way to identify taxonomic differences in Pliocene and Pleistocene fossil hominins. The present study has identified changes in both M(1) crown size and cusp proportions within the genus Homo, with M(1) overall crown size reduction apparently occurring in two main stages. The first stage (a reduction of ca. 17%) is associated with the emergence of Homo ergaster and Homo erectus sensu stricto. The second stage (a reduction of ca. 10%) occurs in Homo sapiens, but the reduced modern human M(1) tooth crown size was only attained in Upper Paleolithic times. The absolute sizes of the individual cusps are highly positively correlated with overall crown size and dental reduction produces a reduction in the absolute size of each of the cusps. Most of the individual cusps scale isometrically with crown size, but the paracone shows a negative allometric relationship, indicating that the reduction in paracone size is less than in the other M(1) cusps. Thus, the phylogenetically oldest cusp in the upper molars also seems to be the most stable cusp (at least in the M(1)). The most striking change in M(1) cusp proportions is a change in the relative size of the areas of the paracone and metacone. The combination of a small relative paracone and a large relative metacone generally characterizes specimens attributed to early Homo, and the presence of this character state in Australopithecus and Paranthropus suggests it may represent the primitive condition for the later part of the hominin clade. In contrast, nearly all later Homo taxa, with the exception of Homo antecessor, show the opposite condition (i.e. a relatively large paracone and a relatively small metacone). This change in the relationship between the relative sizes of the paracone and metacone is related to an isometric reduction of the absolute size of the metacone. This metacone reduction occurs in the context of relative

  13. Thoracic type Ia endoleak: direct percutaneous coil embolization of the aortic arch at the blood entry site after TEVAR and double-chimney stent-grafts

    Energy Technology Data Exchange (ETDEWEB)

    Bangard, Christopher; Franke, Mareike; Maintz, David; Chang, De-Hua [University Hospital, University of Cologne, Department of Radiology, Cologne (Germany); Pfister, Roman [University Hospital, University of Cologne, Department of Internal Medicine III, Cologne (Germany); Deppe, Antje-Christin [University Hospital, University of Cologne, Department of Cardiothoracic Surgery, Cologne (Germany); Matoussevitch, Vladimir [University Hospital, University of Cologne, Department of Vascular Surgery, Cologne (Germany)

    2014-06-15

    To introduce a novel percutaneous technique to stop blood entry at the lesser aortic arch curvature by coil embolisation in type Ia endoleak after TEVAR. A 61-year-old Marfan patient presented with type Ia endoleak of the aortic arch and a growing aortic arch pseudoaneurysm after TEVAR. Multiple preceding operations and interventions made an endovascular approach unsuccessful. Direct percutaneous puncture of the aneurysmal sac would have cured the sign, but not the cause of blood entry at the lesser curvature of the aortic arch. Direct CT-guided percutaneous puncture of the blood entry site in the aortic arch with fluoroscopically guided coil embolisation using detachable extra-long coils was successfully performed. Three weeks after the intervention, the patient developed fever because of superinfection of the pseudoaneurysm. The blood cultures and CT-guided mediastinal aspirate were sterile. After intravenous administration of antibiotics, the fever disappeared and the patient recovered. Six-month follow-up showed permanent closure of the endoleak and a shrinking aneurysmal sac. Direct percutaneous puncture of the aortic arch at the blood entry site of a thoracic type Ia endoleak after TEVAR and double-chimney stent-grafts with coil embolisation of the wedge-shaped space between the lesser aortic curvature and the stent-graft is possible. (orig.)

  14. Thoracic type Ia endoleak: direct percutaneous coil embolization of the aortic arch at the blood entry site after TEVAR and double-chimney stent-grafts

    International Nuclear Information System (INIS)

    To introduce a novel percutaneous technique to stop blood entry at the lesser aortic arch curvature by coil embolisation in type Ia endoleak after TEVAR. A 61-year-old Marfan patient presented with type Ia endoleak of the aortic arch and a growing aortic arch pseudoaneurysm after TEVAR. Multiple preceding operations and interventions made an endovascular approach unsuccessful. Direct percutaneous puncture of the aneurysmal sac would have cured the sign, but not the cause of blood entry at the lesser curvature of the aortic arch. Direct CT-guided percutaneous puncture of the blood entry site in the aortic arch with fluoroscopically guided coil embolisation using detachable extra-long coils was successfully performed. Three weeks after the intervention, the patient developed fever because of superinfection of the pseudoaneurysm. The blood cultures and CT-guided mediastinal aspirate were sterile. After intravenous administration of antibiotics, the fever disappeared and the patient recovered. Six-month follow-up showed permanent closure of the endoleak and a shrinking aneurysmal sac. Direct percutaneous puncture of the aortic arch at the blood entry site of a thoracic type Ia endoleak after TEVAR and double-chimney stent-grafts with coil embolisation of the wedge-shaped space between the lesser aortic curvature and the stent-graft is possible. (orig.)

  15. Examination of ceramic restoration adhesive coverage in cusp-replacement premolar using acoustic emission under fatigue testing

    OpenAIRE

    Chang, Yen-Hsiang; Yu, Jin-Jie; Lin, Chun-Li

    2014-01-01

    Background This study investigates CAD/CAM ceramic cusp-replacing restoration resistance with and without buccal cusp replacement under static and dynamic cyclic loads, monitored using the acoustic emission (AE) technique. Method The cavity was designed in a typical MODP (mesial-occlusal-distal-palatal) restoration failure shape when the palatal cusp has been lost. Two ceramic restorations [without coverage (WOC) and with (WC) buccal cuspal coverage with 2.0 mm reduction in cuspal height] wer...

  16. Cluster survey of the high-altitude cusp properties: a three-year statistical study

    Directory of Open Access Journals (Sweden)

    B. Lavraud

    2004-09-01

    Full Text Available The global characteristics of the high-altitude cusp and its surrounding regions are investigated using a three-year statistical survey based on data obtained by the Cluster spacecraft. The analysis involves an elaborate orbit-sampling methodology that uses a model field and takes into account the actual solar wind conditions and level of geomagnetic activity. The spatial distribution of the magnetic field and various plasma parameters in the vicinity of the low magnetic field exterior cusp are determined and it is found that: 1 The magnetic field distribution shows the presence of an intermediate region between the magnetosheath and the magnetosphere: the exterior cusp, 2 This region is characterized by the presence of dense plasma of magnetosheath origin; a comparison with the Tsyganenko (1996 magnetic field model shows that it is diamagnetic in nature, 3 The spatial distributions show that three distinct boundaries with the lobes, the dayside plasma sheet and the magnetosheath surround the exterior cusp, 4 The external boundary with the magnetosheath has a sharp bulk velocity gradient, as well as a density decrease and temperature increase as one goes from the magnetosheath to the exterior cusp, 5 While the two inner boundaries form a funnel, the external boundary shows no clear indentation, 6 The plasma and magnetic pressure distributions suggest that the exterior cusp is in equilibrium with its surroundings in a statistical sense, and 7 A preliminary analysis of the bulk flow distributions suggests that the exterior cusp is stagnant under northward IMF conditions but convective under southward IMF conditions.

  17. MDCT evaluation of acute aortic syndrome (AAS).

    Science.gov (United States)

    Valente, Tullio; Rossi, Giovanni; Lassandro, Francesco; Rea, Gaetano; Marino, Maurizio; Muto, Maurizio; Molino, Antonio; Scaglione, Mariano

    2016-05-01

    Non-traumatic acute thoracic aortic syndromes (AAS) describe a spectrum of life-threatening aortic pathologies with significant implications on diagnosis, therapy and management. There is a common pathway for the various manifestations of AAS that eventually leads to a breakdown of the aortic intima and media. Improvements in biology and health policy and diffusion of technology into the community resulted in an associated decrease in mortality and morbidity related to aortic therapeutic interventions. Hybrid procedures, branched and fenestrated endografts, and percutaneous aortic valves have emerged as potent and viable alternatives to traditional surgeries. In this context, current state-of-the art multidetector CT (MDCT) is actually the gold standard in the emergency setting because of its intrinsic diagnostic value. Management of acute aortic disease has changed with the increasing realization that endovascular therapies may offer distinct advantages in these situations. This article provides a summary of AAS, focusing especially on the MDCT technique, typical and atypical findings and common pitfalls of AAS, as well as recent concepts regarding the subtypes of AAS, consisting of aortic dissection, intramural haematoma, penetrating atherosclerotic ulcer and unstable aortic aneurysm or contained aortic rupture. MDCT findings will be related to pathophysiology, timing and management options to achieve a definite and timely diagnostic and therapeutic definition. In the present article, we review the aetiology, pathophysiology, clinical presentation, outcomes and therapeutic approaches to acute aortic syndromes. PMID:27033344

  18. Transcatheter aortic valve implantation versus surgical aortic valve replacement for severe aortic stenosis: a meta analysis

    Institute of Scientific and Technical Information of China (English)

    WU Yi-cheng; ZHANG Jian-feng; SHEN Wei-feng; ZHAO Qiang

    2013-01-01

    Background Transcatheter aortic valve implantation (TAVI) has emerged as the treatment choice for non-operable patients with severe symptomatic aortic stenosis (AS) and may be a good alternative to surgery for those at very high or prohibitive surgical risk.We performed a meta-analysis to evaluate the comparative benefits of TAVI versus surgical aortic valve replacement (SAVR) in patients with severe AS.Methods A comprehensive literature search of PubMed,Embase,ScienceDirect and Cochrane Central Register of Controlled trials was performed,and randomized trials as well as cohort studies with propensity score analysis were included.Results One randomized trial (n=699) and six retrospective cohort studies (n=781) were selected for meta-analysis.Mortality at 30-day and 1-year follow-up was comparable between TAVI and SAVR.Despite similar incidences of stroke,myocardial infarction,re-operation for bleeding,and renal failure requiring dialysis,TAVI was associated with a lower occurrence rate of new-onset atrial fibrillation (OR 0.51,95% CI 0.33-0.78) and shorter procedural time (mean difference -67.50 minutes,95% CI-87.20 to-47.81 minutes).Post-operative aortic regurgitation and permanent pacemaker implantation were more common in patients after TAVI than in those with SAVR (OR 5.53,95% CI 3.41-8.97; OR 1.71,95% Cl 1.02-2.84,respectively).Conclusion In patients with severe symptomatic AS,TAVI and SAVR did not differ with respect to short-and mid-term survival,but the incidence of permanent pacemaker implantation and post-procedural aortic regurgitation remain relatively high after TAVI.

  19. Indexing aortic valve area by body surface area increases the prevalence of severe aortic stenosis

    DEFF Research Database (Denmark)

    Jander, Nikolaus; Gohlke-Bärwolf, Christa; Bahlmann, Edda;

    2014-01-01

    To account for differences in body size in patients with aortic stenosis, aortic valve area (AVA) is divided by body surface area (BSA) to calculate indexed AVA (AVAindex). Cut-off values for severe stenosis are...

  20. ESR and EISCAT observations of the response of the cusp and cleft to IMF orientation changes

    Directory of Open Access Journals (Sweden)

    I. W. McCrea

    Full Text Available We report observations of the cusp/cleft ionosphere made on December 16th 1998 by the EISCAT (European incoherent scatter VHF radar at Tromsø and the EISCAT Svalbard radar (ESR. We compare them with observations of the dayside auroral luminosity, as seen by meridian scanning photometers at Ny Ålesund and of HF radar backscatter, as observed by the CUTLASS radar. We study the response to an interval of about one hour when the interplanetary magnetic field (IMF, monitored by the WIND and ACE spacecraft, was southward. The cusp/cleft aurora is shown to correspond to a spatially extended region of elevated electron temperatures in the VHF radar data. Initial conditions were characterised by a northward-directed IMF and cusp/cleft aurora poleward of the ESR. A strong southward turning then occurred, causing an equatorward motion of the cusp/cleft aurora. Within the equatorward expanding, southward-IMF cusp/cleft, the ESR observed structured and elevated plasma densities and ion and electron temperatures. Cleft ion fountain upflows were seen in association with elevated ion temperatures and rapid eastward convection, consistent with the magnetic curvature force on newly opened field lines for the observed negative IMF By. Subsequently, the ESR beam remained immediately poleward of the main cusp/cleft and a sequence of poleward-moving auroral transients passed over it. After the last of these, the ESR was in the polar cap and the radar observations were characterised by extremely low ionospheric densities and downward field-aligned flows. The IMF then turned northward again and the auroral oval contracted such that the ESR moved back into the cusp/cleft region. For the poleward-retreating, northward-IMF cusp/cleft, the convection flows were slower, upflows were weaker and the electron density and temperature enhancements were less structured. Following the northward turning, the bands of high electron temperature and cusp

  1. Early outcomes of transcatheter aortic valve replacement in patients with severe aortic stenosis: single center experience

    OpenAIRE

    Bozkurt, Engin; KELEŞ, TELAT; Durmaz, Tahir; Akçay, Murat; Sari, Cenk; Ayhan, Hüseyin; Bayram, Nihal Akar; Aslan, Abdullah Nabi; Baştuğ, Serdal; Bilen, Emine

    2014-01-01

    Introduction Transcatheter aortic valve implantation is a promising alternative to high risk surgical aortic valve replacement. The procedure is mainly indicated in patients with severe symptomatic aortic stenosis who cannot undergo surgery or who are at very high surgical risk. Aim Description early results of our single-center experience with balloon expandable aortic valve implantation. Material and methods Between July 2011 and August 2012, we screened in total 75 consecutive patients wit...

  2. Electron beam characteristics in the hollow beam diode and cusped magnetic field of the Maryland ERA

    International Nuclear Information System (INIS)

    The University of Maryland electron ring accelerator (ERA) concept calls for the formation of an electron ring current by transmission of a hollow relativistic electron beam through a static, azimuthally symmetric, cusped magnetic field. Electron motion is approximately paraxial in the diode and pre-cusp drift region and is axis-encircling in the post-cusp region. Experiments show the electron flow in the diode to be approximately pressureless. The radial thickness of the drifting Brillouin hollow beam is derived from a radial force balance equation. Time-resolved measurements of the beam current and energy are made by measuring the extrapolated range of the beam in aluminum targets. These measurements are analyzed with a model of the diode as a terminating impedance driven by a transmission line. Beam motion in the cusped field region is analyzed. Beam dynamics in the post-cusp region are studied by examining the interaction of a hollow rotating beam with its self-induced potentials in a cylindrical box with conducting walls and ends. The energy of the self-induced electric and magnetic potentials is much less than the kinetic energy of the beam electrons for cases approximating experimental conditions

  3. Cluster observations of the mid-altitude cusp under strong northward Interplanetary Magnetic Field

    CERN Document Server

    Hu, Renyu; Owen, Christopher J; Foullon, Claire; Fazakerley, Andrew N; Reme, Henri

    2008-01-01

    We report on a Cluster multi-spacecraft cusp observation lasting more than 100 minutes. We determine the cusp boundary motion and reveal the effect on the cusp size of the interplanetary magnetic field (IMF) changing from southward to northward. The cusp shrinks at the beginning of the IMF rotation and it re-expands at the rate of 0.50$^{o}$ ILAT per hour under stable northward IMF. Based on plasma signatures inside the cusp, such as counter-streaming electrons with balanced fluxes and quasi-periodic enhancement of ion fluxes with energy E$>$5keV, we propose that pulsed dual lobe reconnection operates during the time of interest. SC1 and SC4 observations suggest a long-term regular periodicity of the pulsed dual reconnection, which we estimate to be $\\sim$ 1-5 minutes. Further, the distances from the spacecraft to the reconnection site are estimated based on observations from three satellites. The distance determined using SC1 and SC4 observations is $\\sim$ 15 RE, and that determined from SC3 data is $\\sim$ 8...

  4. Field lin topology in the dayside cusp region inferred from low altitude particle observations

    International Nuclear Information System (INIS)

    Dayside low altitude satellite observations of the pitch angle and energy distribution of electrons and protons in the energy range 1 keV to 100 keV during quiet geomagnetic conditions reveal that at times there is a clear latitudinal separation between the precipitating low energy (keV) electrons and protons, with the protons precipitating poleward of the electrons. The high energy (100keV) proton precipitation overlaps both the low energy electron and proton precipitation. These observations are consistent with a model where magnetosheath particles stream in along the cusp field lines and are at the same time convected poleward by an electric field. Electrons with energies of a few keV move fast and give the ''ionospheric footprint'' of the distant cusp. The protons are partly convected poleward of the cusp and into the polar cap. Here the mirroring protons populate the plasma mantle. Equatorward of the cusp the pitch angle distribution of both electrons and protons with energies above a few keV have a pancake shaped distribution indicating closed geomagnetic field lines. The 1 keV electrons penetrate into this region of closed field line structure maintaining an isotropic pitch angle distribution. The intensity is, however, reduced with respect to what it was in the cusp region. It is suggested that these electrons, the lowest measured on the satellite, are associated with the entry layer.(Auth.)

  5. On the cusp anomalous dimension in the ladder limit of $\\mathcal N=4$ SYM

    CERN Document Server

    Beccaria, Matteo; Macorini, Guido

    2016-01-01

    We analyze the cusp anomalous dimension in the (leading) ladder limit of $\\mathcal N=4$ SYM and present new results for its higher-order perturbative expansion. We study two different limits with respect to the cusp angle $\\phi$. The first is the light-like regime where $x = e^{i\\,\\phi}\\to 0$. This limit is characterised by a non-trivial expansion of the cusp anomaly as a sum of powers of $\\log x$, where the maximum exponent increases with the loop order. The coefficients of this expansion have remarkable transcendentality features and can be expressed by products of single zeta values. We show that the whole logarithmic expansion is fully captured by a solvable Woods-Saxon like one-dimensional potential. From the exact solution, we extract generating functions for the cusp anomaly as well as for the various specific transcendental structures appearing therein. The second limit that we discuss is the regime of small cusp angle. In this somewhat simpler case, we show how to organise the quantum mechanical pert...

  6. THE NONLINEAR CUSP-CATASTROPHE MODEL OF THE SEDIMENT TRANSPORT RATE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the catastrophe theory of nonlinear science,the intensity of water-flow and the coefficient of non-uniformsediment m are regarded as two bound variables, and the in-tensity of bed-load transport Φ as the state variable in the mo-tion of non-uniform sediment in cusp-catastrophe model.Based on the standard equation of the cusp-catastrophe theo-ry, the relation equation between the intensity of bed-loadtransport Φ and the intensity of water-flow has been derivedby used coordinate transform and topology transform. The e-quation of bed load transport rate was built on the cusp-catas-trophe theory of nonlinear science. The others are applied toverify this equation, that the results calculated by the cusp-ca-tastrophe equation agree well with the other equations. Thisindicates that the cusp-catastrophe equation is reasonable, and the results fully reflect the characteristics of threshold motionand transport of non-uniform sediment. The purpose of thispaper is to explore the incipient motion and transport laws ofnon-uniform sediment from the viewpoint of nonlinear science.

  7. MARFAN SYNDROME AND QUADRICUSPID AORTIC VALVE

    OpenAIRE

    Sürücü, Hüseyin; ÇİMEN, Sadi

    2013-01-01

    ABSTRACTWhile the major cardiovascular manifestation in Marfan syndrome is a progressive dilatation of the ascending aorta, leading to aortic aneurysm formation and eventually to fatal aortic rupture or dissection, mitral valve prolapse and calcification of the mitral valve annulus, dilatation of the main pulmonary artery may be seen. There was no knowledge about the association of Marfan syndrome and quadricuspid aortic valve. In this case report, we aimed to declare this association between...

  8. Recurrent tamponade and aortic dissection in syphilis.

    Science.gov (United States)

    Stansal, Audrey; Mirault, Tristan; Rossi, Aude; Dupin, Nicolas; Bruneval, Patrick; Bel, Alain; Azarine, Arshid; Minozzi, Catherine; Deman, Anne Laure; Messas, Emmanuel

    2013-11-01

    Syphilitic cardiovascular disease has been described since the 19th century, mainly on autopsy series. Major clinical manifestations are aortic aneurysm, aortic insufficiency, and coronary ostial stenosis. The diagnosis of syphilitic cardiovascular disease is based mainly on positive serologic tests and overt clinical manifestations. We present here a rare and unusual clinical presentation of a tertiary syphilis with recurrent tamponade and type B aortic dissection, whose positive diagnosis was made by polymerase chain reaction on pericardial fluid analysis. PMID:24182507

  9. Treatment options for postdissection aortic aneurysms.

    Science.gov (United States)

    Sobocinski, Jonathan; Patterson, Benjamin O; Clough, Rachel E; Spear, Rafaelle; Martin-Gonzalez, Teresa; Azzaoui, Richard; Hertault, Adrien; Haulon, Stéphan

    2016-04-01

    Aortic dissection is one of the most devastating catastrophes that can affect the aorta. Surgical treatment is proposed only when complications such as rupture or malperfusion occur. No clear consensus has been reached regarding the best therapy to prevent aortic rupture after the acute phase. We have performed a thorough review of the most recent literature on the strategies to treat patients in the chronic phase of aortic dissection. PMID:26771869

  10. Clinical application of CT virtual endoscopy in the diagnosis of aortic diseases

    International Nuclear Information System (INIS)

    Objective: To evaluate the display ability and the clinical application of CT virtual endoscopy (CTVE) in the diagnosis of aortic disease. Methods: In this group, 147 cases with clinically suspected aortic disease (113 males, 34 females) underwent CTVE and 58 cases had DSA for comparison. 37 cases were confirmed by operation. Results: (1) In the 147 cases, 139 cases showed successful CTVE images. (2) CTVE images could clearly show the inner wall and inner structures of the vessels, the true and false luminal of aortic dissections, and the lesion of false aneurysm. Conclusion: CTVE could provide more information of the vessel by displaying the inner wall and allowing users to map the vessels in a display. It is helpful in correct diagnosis and guiding surgery

  11. Hybrid treatment of penetrating aortic ulcer

    Energy Technology Data Exchange (ETDEWEB)

    Lara, Juan Antonio Herrero; Martins-Romeo, Daniela de Araujo; Escudero, Carlos Caparros; Falcon, Maria del Carmen Prieto; Batista, Vinicius Bianchi, E-mail: jaherrero5@hotmail.com [Unidade de Gestao Clinica (UGC) de Diagnostico por Imagem - Hosppital Universitario Virgen Macarena, Sevilha (Spain); Vazquez, Rosa Maria Lepe [Unit of Radiodiagnosis - Hospital Nuestra Senora de la Merced, Osuna, Sevilha (Spain)

    2015-05-15

    Penetrating atherosclerotic aortic ulcer is a rare entity with poor prognosis in the setting of acute aortic syndrome. In the literature, cases like the present one, located in the aortic arch, starting with chest pain and evolving with dysphonia, are even rarer. The present report emphasizes the role played by computed tomography in the diagnosis of penetrating atherosclerotic ulcer as well as in the differentiation of this condition from other acute aortic syndromes. Additionally, the authors describe a new therapeutic approach represented by a hybrid endovascular surgical procedure for treatment of the disease. (author)

  12. Abdominal Aortic Surgery: Anesthetic Implications

    OpenAIRE

    Cunningham, Anthony J.

    1991-01-01

    The objectives of the review are to highlight the clinical characteristics of the patient population; to assess multivariate risk factor analysis and the invasive/non-invasive techniques available for risk factor identification and management in this high-risk surgical population; to assess the major hemodynamic, metabolic, and regional blood flow changes associated with aortic cross-clamping/unclamping procedures and techniques for their modification or attenuation; and to assess the influen...

  13. Transverse Aortic Constriction in Mice

    OpenAIRE

    deAlmeida, Angela C.; van Oort, Ralph J.; Wehrens, Xander H. T.

    2010-01-01

    Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model for pressure overload-induced cardiac hypertrophy and heart failure.1 TAC initially leads to compensated hypertrophy of the heart, which often is associated with a temporary enhancement of cardiac contractility. Over time, however, the response to the chronic hemodynamic overload becomes maladaptive, resulting in cardiac dilatation and heart failure.2 The murine TAC model was first validated by Rockman et ...

  14. Holographic cusped Wilson loops in q-deformed AdS5 × S5 spacetime

    Science.gov (United States)

    Bai, Nan; Chen, Hui-Huang; Wu, Jun-Bao

    2015-10-01

    In this paper, a minimal surface in q-deformed AdS5×S5 with a cusp boundary is studied in detail. This minimal surface is dual to a cusped Wilson loop in dual field theory. We find that the area of the minimal surface has both logarithmic squared divergence and logarithmic divergence. The logarithmic squared divergence cannot be removed by either Legendre transformation or the usual geometric subtraction. We further make an analytic continuation to the Minkowski signature, taking the limit such that the two edges of the cusp become light-like, and extract the anomalous dimension from the coefficient of the logarithmic divergence. This anomalous dimension goes back smoothly to the results in the undeformed case when we take the limit that the deformation parameter goes to zero. Supported by National Natural Science Foundation of China (11105154, 11222549, 11275207), K. C. Wong Education Foundation and Youth Innovation Promotion Association of CAS

  15. Model of magnetosheath plasma in the magnetosphere: Cusp and mantle particles at low-altitudes

    International Nuclear Information System (INIS)

    A model of plasma transport in the open magnetic field region of the dayside magnetosphere has been used to investigate the source regions and the distribution of solar wind plasma in the magnetospheric cusp and mantle. This model includes the variation in the magnetosheath properties as the plasma accelerates away from the subsolar point, the variation in the transport of magnetosheath plasma across the magnetopause as the orientation of the magnetic field line evolves following reconnection, and the transport of the magnetosheath plasma within the magnetosphere. The authors' model results are compared with low-altitude spacecraft data from a crossing of the cusp and mantle. They find qualitative and quantitative agreement between the model results and the data. This agreement suggests that the zeroth-order processes included in the model are sufficient to reproduce the commonly observed particle distributions in the low-altitude cusp and mantle regions. 16 refs., 2 figs

  16. Utilising copper screen-printed electrodes (CuSPE) for the electroanalytical sensing of sulfide.

    Science.gov (United States)

    Thakur, Bhawana; Bernalte, Elena; Smith, Jamie P; Foster, Christopher W; Linton, Patricia E; Sawant, Shilpa N; Banks, Craig E

    2016-02-01

    A mediatorless sulfide electrochemical sensing platform utilising a novel nanocopper-oxide screen-printed electrodes (CuSPE) is reported for the first time. The state-of-the-art screen-printed electrochemical sensors demonstrate their capability to quantify sulfide within both the presence and absence of an array of interferents with good levels of sensitivity and repeatability. The direct sensing (using linear sweep voltammetry) of sulfide utilising the CuSPEs provides a mediatorless approach for the detection of sulfide, yielding useful analytical signatures that can be successfully quantified. The proposed novel protocol using the CuSPEs is successfully applied to the sensing of sulfide within drinking water exhibiting a high level of recovery. PMID:26815001

  17. The variation of reconnection rate at the dayside magnetopause and cusp ion precipitation

    Science.gov (United States)

    Lockwood, M.; Smith, M. F.

    1992-01-01

    A method is presented which allows estimation of the variation of the rate of magnetic reconnection at the dayside magnetopause. This is achieved using observations of the cusp particle precipitation made by low-altitude polar-orbiting spacecraft. In this paper we apply the technique to a previously published example of a cusp intersection by the DMSP F7 satellite. It is shown that the cusp signature in this case was produced by three separate bursts of reconnection which were of the order of 10 min apart, each lasting roughly 1 min. This is similar to the variation of reconnection rate which is required to explain typical flux transfer event signatures at the magnetopause.

  18. First Cluster results of the magnetic field structure of the mid- and high-altitude cusps

    Directory of Open Access Journals (Sweden)

    P. J. Cargill

    Full Text Available Magnetic field measurements from the four Cluster spacecraft from the mid- and high-altitude cusp are presented. Cluster underwent two encounters with the mid-altitude cusp during its commissioning phase (24 August 2000. Evidence for field-aligned currents (FACs was seen in the data from all three operating spacecraft from northern and southern cusps. The extent of the FACs was of the order of 1 RE in the X-direction, and at least 300 km in the Y-direction. However, fine-scale field structures with scales of the order of the spacecraft separation (300 km were observed within the FACs. In the northern crossing, two of the spacecraft appeared to lie along the same magnetic field line, and observed very well matched signals. However, the third spacecraft showed evidence for structuring transverse to the field on scales of a few hundred km. A crossing of the high-altitude cusp from 13 February 2001 is presented. It is revealed to be a highly dynamic structure with the boundaries moving with velocities ranging from a few km/s to tens of km/s, and having structure on timescales ranging from less than one minute up to several minutes. The cusp proper is associated with the presence of a very disordered magnetic field, which is entirely different from the magnetosheath turbulence.

    Key words. Magnetospheric physics (current systems; magnetopause, cusp, and boundary layers – Space plasma physics (discontinuities

  19. Ethnic Association of Cusp of Carabelli Trait and Shoveling Trait in an Indian Population

    Science.gov (United States)

    Manju, M; Praveen, R; Umesh, W

    2016-01-01

    Introduction Variations in the structure of teeth have always been of great interest to the dentist from the scientific as well as practical point of view. Additionally, ever since decades inter trait relationships have been a useful means to categorize populations to which an individual belongs. Aim To determine the association between Cusp of Carabelli and Shoveling Trait in a selected Indian population native of Bangalore city, Karnataka, India. Materials and Methods A cross-sectional study was carried out in 1885 children aged between 7-10 years. Casts of the study subjects were made to study the presence of Cusp of Carabelli of right maxillary permanent molar and shoveling trait of right maxillary permanent central incisor using the Dahlberg’s classification and Hrdliucka’s classification respectively. Linear regression was used to assess the association of cusp of carabelli trait with the tooth dimensions and logistic regression was used to evaluate the association of the carabelli trait with gender and presence/absence of shoveling. Results A 40.5% of subjects had Cusp of Carabelli on first molar and 68.2% had shoveling on upper central incisor. The study revealed positive association between the two traits studied in the population. A significant difference was also found with presence of Cusp of Carabelli and the buccolingual tooth dimension of the maxillary molar (p<0.05). Conclusion There is an association between the Cusp of Carabelli and the shoveling trait in the present study population, and this will be valuable in the determination of ethnic origin of an individual. PMID:27135008

  20. Analysis of a slow-fast system near a cusp singularity

    OpenAIRE

    Jardón-Kojakhmetov, H.; Broer, Henk W.; Roussarie, R.

    2015-01-01

    This paper studies a slow-fast system whose principal characteristic is that the slow manifold is given by the critical set of the cusp catastrophe. Our analysis consists of two main parts: first, we recall a formal normal form suitable for systems as the one studied here; afterwards, taking advantage of this normal form, we investigate the transition near the cusp singularity by means of the blow up technique. Our contribution relies heavily in the usage of normal form theory, allowing us to...

  1. Weak annihilation cusp inside the dark matter spike about a black hole

    OpenAIRE

    Shapiro, Stuart L.; Shelton, Jessie

    2016-01-01

    We reinvestigate the effect of annihilations on the distribution of collisionless dark matter (DM) in a spherical density spike around a massive black hole. We first construct a very simple, pedagogic, analytic model for an isotropic phase space distribution function that accounts for annihilation and reproduces the "weak cusp" found by Vasiliev for DM deep within the spike and away from its boundaries. The DM density in the cusp varies as $r^{-1/2}$ for $s$-wave annihilation, where $r$ is th...

  2. Cusp points in the parameter space of RPR-2PRR parallel manipulator

    OpenAIRE

    Moroz, Guillaume; Chablat, Damien; Wenger, Philippe; Rouillier, Fabrice

    2010-01-01

    This paper investigates the existence conditions of cusp points in the design parameter space of the R\\underline{P}R-2P\\underline{R}R parallel manipulators. Cusp points make possible non-singular assembly-mode changing motion, which can possibly increase the size of the aspect, i.e. the maximum singularity free workspace. The method used is based on the notion of discriminant varieties and Cylindrical Algebraic Decomposition, and resorts to Gr\\"obner bases for the solutions of systems of equa...

  3. Real time evolvable hardware for optimal reconfiguration of cusp-like pulse shapers

    International Nuclear Information System (INIS)

    The design of a cusp-like digital pulse shaper for particle energy measurements requires the definition of four parameters whose values are defined based on the nature of the shaper input signal (timing, noise, …) provided by a sensor. However, after high doses of radiation, sensors degenerate and their output signals do not meet the original characteristics, which may lead to erroneous measurements of the particle energies. We present in this paper an evolvable cusp-like digital shaper, which is able to auto-recalibrate the original hardware implementation into a new design that match the original specifications under the new sensor features

  4. Semiclassical partition function for strings dual to Wilson loops with small cusps in ABJM

    CERN Document Server

    Aguilera-Damia, Jeremias; Silva, Guillermo A

    2014-01-01

    We compute the 1-loop partition function for strings in $AdS_4\\times\\mathbb{CP}^3$, whose worldsheets end along a line with small cusp angles in the boundary of AdS. We obtain these 1-loop results in terms of the vacuum energy for on-shell modes. Our results verify the proposal by Lewkowycz and Maldacena in arXiv:1312.5682 for the exact Bremsstrahlung function up to the next to leading order in the strong coupling expansion. The agreement is observed for cusps distorting either the 1/2 BPS or the 1/6 BPS Wilson line.

  5. Semiclassical partition function for strings dual to Wilson loops with small cusps in ABJM

    Science.gov (United States)

    Aguilera-Damia, Jeremías; Correa, Diego H.; Silva, Guillermo A.

    2015-03-01

    We compute the 1-loop partition function for strings in , whose worldsheets end along a line with small cusp angles in the boundary of AdS. We obtain these 1-loop results in terms of the vacuum energy for on-shell modes. Our results verify the proposal by Lewkowycz and Maldacena in arXiv:1312.5682 for the exact Bremsstrahlung function up to the next to leading order in the strong coupling expansion. The agreement is observed for cusps distorting either the 1/2 BPS or the 1/6 BPS Wilson line.

  6. Endodontic Treatment and Esthetic Management of a Geminated Central Incisor Bearing a Talon Cusp

    Directory of Open Access Journals (Sweden)

    Elif Tarım Ertaş

    2014-01-01

    Full Text Available Gemination with talon cusps is an uncommon morphologic dental anomaly, characterized by the formation of clinically wide tooth that can cause significant aesthetic and clinical problems including esthetic impairment, pain, caries susceptibility, and tooth crowding. These morphological dental anomalies have specific treatment needs due to the abnormal morphology and need virtuous radiologic diagnosis. Multidisciplinary approach can supply success of the treatment plan that can provide esthetic and occlusal requirements. In this case report, the multidisciplinary approach for the treatment of geminated tooth with talon cusp is presented with the clinical and radiographic findings.

  7. Aberration-like cusped focusing in the post-paraxial Talbot effect

    Science.gov (United States)

    Ring, James D.; Lindberg, Jari; Howls, Christopher J.; Dennis, Mark R.

    2012-07-01

    We present an analysis of the Talbot effect beyond the paraxial regime, where deviation from Fresnel propagation destroys perfect, periodic self-imaging. The resulting interference structures are examples of aberration without geometric optical rays, which we describe analytically using post-paraxial theory. They are similar to, but do not precisely replicate, a standard integral representation of a diffraction cusp (the Pearcey function). Beyond the Talbot effect, this result illustrates that aberration—as the replacement of a perfect focus with a cusp-like pattern—can occur as a consequence of improving the paraxial approximation, rather than due to imperfections in the optical system.

  8. Aberration-like cusped focusing in the post-paraxial Talbot effect

    International Nuclear Information System (INIS)

    We present an analysis of the Talbot effect beyond the paraxial regime, where deviation from Fresnel propagation destroys perfect, periodic self-imaging. The resulting interference structures are examples of aberration without geometric optical rays, which we describe analytically using post-paraxial theory. They are similar to, but do not precisely replicate, a standard integral representation of a diffraction cusp (the Pearcey function). Beyond the Talbot effect, this result illustrates that aberration—as the replacement of a perfect focus with a cusp-like pattern—can occur as a consequence of improving the paraxial approximation, rather than due to imperfections in the optical system. (paper)

  9. Cusp Anomalous dimension and rotating open strings in AdS/CFT

    CERN Document Server

    Espíndola, R

    2016-01-01

    In the context of AdS/CFT we provide analytical support for the proposed duality between a Wilson loop with a cusp, the cusp anomalous dimension, and the meson model constructed from a rotating open string with high angular momentum. This duality was previously studied using numerical tools in [1]. Our result implies that the minimum of the profile function of the minimal area surface dual to the Wilson loop, is related to the inverse of the bulk penetration of the dual string that hangs from the quark--anti-quark pair (meson) in the gauge theory.

  10. [Surgical aspects of acute aortic dissection].

    Science.gov (United States)

    Laas, J; Heinemann, M; Jurmann, M; Borst, H G

    1992-12-01

    This paper highlights some of the surgical aspects of acute aortic dissections such as: emergency diagnosis, indications for surgery, reconstructive operative techniques, malperfusion phenomena and necessity for follow-up. Aortic dissection is caused by an intimal tear, called the "entry", and subsequent splitting of the media by the stream of blood. Two lumina are thus created, which may communicate through "re-entries". As this creates severe weakness of the aortic wall, rupture and/or dilatation are the imminent dangers of acute aortic dissection. Acute aortic dissection type A, by definition involving the ascending aorta (Figures 1 and 2), is an absolute indication for emergency surgical treatment, because its natural history shows an extremely poor outcome (Figure 3). Due to impending (intrapericardial) aortic rupture, it may be necessary to limit diagnostic procedures to a minimum. Transesophageal echocardiography is the method of choice for establishing a quick, precise and reliable diagnosis (Figure 4). In stable patients, computed tomography gives additional information about aortic diameters or sites of extrapericardial perforation. Digital subtraction angiography (DSA) shows perfusion of the lumina and dependent organs. The surgical strategy in acute aortic dissection type A aims at replacement of the ascending aorta. Reconstructive techniques have to be considered, especially in aortic valve regurgitation without annuloectasia (Figures 5 and 6). In recent times, the use of GRF tissue glue has reduced the need for teflon felt. Involvement of the aortic arch should be treated aggressively up to the point of total arch replacement in deep hypothermic circulatory arrest as part of the primary procedure (Figure 7). Malperfusion phenomena of aortic branches remain risk-factors.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1483624

  11. Pregnancy after aortic root replacement in Loeys-Dietz syndrome: High risk of aortic dissection.

    Science.gov (United States)

    Braverman, Alan C; Moon, Marc R; Geraghty, Patrick; Willing, Marcia; Bach, Christopher; Kouchoukos, Nicholas T

    2016-08-01

    Loeys-Dietz syndrome due to mutations in TGFBR1 and 2 is associated with early and aggressive aortic aneurysm and branch vessel disease. There are reports of uncomplicated pregnancy in this condition, but there is an increased risk of aortic dissection and uterine rupture. Women with underlying aortic root aneurysm are cautioned about the risk of pregnancy-related aortic dissection. Prophylactic aortic root replacement is recommended in women with aortopathy and aortic root dilatation to lessen the risk of pregnancy. There is limited information in the literature about the outcomes of pregnancy after root replacement in Loeys-Dietz syndrome. We present a case series of three women with Loeys-Dietz syndrome who underwent elective aortic root replacement for aneurysm disease and subsequently became pregnant and underwent Cesarean section delivery. Each of these women were treated with beta blockers throughout pregnancy. Surveillance echocardiograms and noncontrast MRA studies during pregnancy remained stable demonstrating no evidence for aortic enlargement. Despite the normal aortic imaging and careful observation, two of the three women suffered acute aortic dissection in the postpartum period. These cases highlight the high risk of pregnancy following aortic root replacement in Loeys-Dietz syndrome. Women with this disorder are recommended to be counseled accordingly. © 2016 Wiley Periodicals, Inc. PMID:27125181

  12. Infected aortic aneurysm and inflammatory aortic aneurysm. In search of an optimal differential diagnosis

    International Nuclear Information System (INIS)

    Infected aortic aneurysm and inflammatory aortic aneurysm each account for a minor fraction of the total incidence of aortic aneurysm and are associated with periaortic inflammation. Despite the similarity, infected aortic aneurysm generally shows a more rapid change in clinical condition, leading to a fatal outcome; in addition, delayed diagnosis and misuse of corticosteroid or immunosuppressing drugs may lead to uncontrolled growth of microorganisms. Therefore, it is mandatory that detection of aortic aneurysm is followed by accurate differential diagnosis. In general, infected aortic aneurysm appears usually as a saccular form aneurysm with nodularity, irregular configuration; however, the differential diagnosis may not be easy sometimes for the following reasons: symptoms, such as abdominal and/or back pain and fever, and blood test abnormalities, such as elevated C-reactive protein and enhanced erythrocyte sedimentation rate, are common in infected aortic aneurysm, but they are not found infrequently in inflammatory aortic aneurysm; some inflammatory aortic aneurysms are immunoglobulin (Ig) G4-related, but not all of them; the prevalence of IgG4 positivity in infected aortic aneurysm has not been well investigated; enhanced uptake of 18F-fluorodeoxyglucose (FDG) by 18F-FDG-positron emission tomography may not distinguish between inflammation mediated by autoimmunity and that mediated by microorganism infection. Here we discuss the characteristics of these two forms of aortic aneurysm and the points of which we have to be aware before reaching a final diagnosis. (author)

  13. Regional aortic distensibility and its relationship with age and aortic stenosis: a computed tomography study.

    Science.gov (United States)

    Wong, Dennis T L; Narayan, Om; Leong, Darryl P; Bertaso, Angela G; Maia, Murilo G; Ko, Brian S H; Baillie, Timothy; Seneviratne, Sujith K; Worthley, Matthew I; Meredith, Ian T; Cameron, James D

    2015-06-01

    Aortic distensibility (AD) decreases with age and increased aortic stiffness is independently associated with adverse cardiovascular outcomes. The association of severe aortic stenosis (AS) with AD in different aortic regions has not been evaluated. Elderly subjects with severe AS and a cohort of patients without AS of similar age were studied. Proximal aortic cross-sectional-area changes during the cardiac cycle were determined using retrospective-ECG-gating on 128-detector row computed-tomography. Using oscillometric-brachial-blood-pressure measurements, the AD at the ascending-aorta (AA), proximal-descending-aorta (PDA) and distal-descending-aorta (DDA) was determined. Linear mixed effects modelling was used to determine the association of age and aortic stenosis on regional AD. 102 patients were evaluated: 36 AS patients (70-85 years), 24 AS patients (>85 years) and 42 patients without AS (9 patients DDA (1.1 ± 1.2 vs. 1.2 ± 0.8, P = 0.97). In patients without AS, AD decreased with age in all aortic regions (P < 0.001). The AA in patients <50 years were the most distensible compared to other aortic regions. There is regional variation in aortic distensibility with aging. Patients with aortic stenosis demonstrated regional differences in aortic distensibility with lower distensibility demonstrated in the proximal ascending aorta compared to an age-matched cohort. PMID:25855464

  14. When and how to replace the aortic root in type A aortic dissection.

    Science.gov (United States)

    Leshnower, Bradley G; Chen, Edward P

    2016-07-01

    Management of aortic root pathology during repair of acute type A aortic dissection (TAAD) requires a comprehensive evaluation of the patient's anatomy, demographics, comorbidities and physiologic status at the time of emergent operative intervention. Surgical options include conservative repair of the root (CRR) (with or without replacement of the aortic valve), replacement of the native valve and aortic root using a composite valve-conduit and valve sparing root replacement (VSRR). The primary objective of this review is to provide data for surgeons to aid in their decision-making process regarding management of the aortic root during repair of TAAD. No time or language restrictions were imposed and references of the selected studies were checked for additional relevant citations. Multiple retrospective reviews have demonstrated equivalent operative mortality between aortic root repair and replacement during TAAD. There is a higher incidence of aortic root reintervention with aortic root repair compared to aortic root replacement (ARR). Experienced, high-volume aortic centers have demonstrated the safety of VSRR in young, hemodynamically stable patients presenting with TAAD. In conclusion, aortic root repair can safely be performed in the vast majority of patients with TAAD. Despite the increased surgical complexity, ARR does not increase operative mortality and improves the freedom from root reintervention. VSRR can be performed in highly selected populations of patients with TAAD with durable mid-term valve function. PMID:27563551

  15. [Unicuspid Aortic Valve Stenosis Combined with Aortic Coarctation;Report of a Case].

    Science.gov (United States)

    Kubota, Takehiro; Wakasa, Satoru; Shingu, Yasushige; Matsui, Yoshiro

    2016-06-01

    Unicuspid aortic valve in an adult is extremely rare. In addition, 90% of the patients with aortic coarctation are reported to die before the age 50. A 60-year-old woman was admitted to our hospital for further examination of exertional dyspnea which had begun one year before. She had been under medical treatment for hypertension since early thirties, and had been also diagnosed with moderate aortic stenosis at 50 years of age. She was at 1st diagnosed with aortic coarctation combined with bicuspid aortic valve stenosis. The aortic valve was then found unicuspid and was replaced under cardiopulmonary bypass with perfusion to both the ascending aorta and the femoral artery. Repair of aortic coarctation was performed 3 months later through left thoracotomy without extracorporeal circulation due to the rich collateral circulation. She had no postoperative complications, and hypertension as well as ankle-brachial index improved to the normal levels. PMID:27246132

  16. Magnetic Resonance Imaging of Thoracic Aortic Dissections

    OpenAIRE

    Sax, Steven L.

    1990-01-01

    Magnetic resonance imaging is an excellent noninvasive method for evaluating thoracic aortic dissections. A variety of magnetic resonance scans of aortic dissections are shown, documenting the ability of magnetic resonance to image the true lumen, the false channel, and the intimal septum. Detail is provided on magnetic resonance imaging techniques and findings. (Texas Heart Institute Journal 1990;17:262-70)

  17. Acute aortic dissection in pregnant women.

    Science.gov (United States)

    Yang, Zhaohua; Yang, Shouguo; Wang, Fangshun; Wang, Chunsheng

    2016-05-01

    Acute aortic dissection occurring during pregnancy represents a lethal risk to both the mother and fetus. Management of parturient with acute aortic dissection is complex. We report our experience of two pregnancies with type A acute aortic dissection. One patient is a 31-year-old pregnant woman (33rd gestational week) with a bicuspid aortic valve and the other is a 32-year-old pregnant woman (30th gestational week) with the Marfan syndrome. In both cases, a combined emergency operation consisting of Cesarean section, total hysterectomy prior to corrective surgery for aortic dissection was successfully performed within a relatively short period of time after the onset. Both patients' postoperative recovery was uneventful, and we achieved a favorable maternal and fetal outcome. PMID:25085319

  18. Transcatheter aortic valve replacement in elderly patients

    Institute of Scientific and Technical Information of China (English)

    Dimytri Siqueira; Alexandre Abizaid; Magaly Arrais J.; Eduardo Sousa

    2012-01-01

    Aortic stenosis is the most common native valve disease, affecting up to 5% of the elderly population. Surgical aortic valve replacement reduces symptoms and improves survival, and is the definitive therapy in patients with symptomatic severe aortic stenosis. However, despite the good results of classic surgery, risk is markedly increased in elderly patients with co-morbidities. Transcatheter aortic valve replacement (TAVR) allows implantation of a prosthetic heart valve within the diseased native aortic valve without the need for open heart surgery and cardiopulmonary bypass, offering a new therapeutic option to elderly patients considered at high surgical risk or with contraindications to surgery. To date, several multicenter registries and a randomized trial have confirmed the safety and efficacy of TAVR in those patients. In this chapter, we review the background and clinical applications of TAVR in elderly patients.

  19. Reoperation on aortic disease in patients with previous aortic valve surgery

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-gang; ZHANG Liang; YU Cun-tao; QIAN Xiang-yang; CHANG Qian

    2013-01-01

    Background Aortic valve replacement (AVR) is a safe and effective method in the treatment of aortic valve diseases.This study aimed to increase the understanding on re-treatment of aortic diseases after aortic valve surgery through a retrospective analysis of 47 related cases.Methods Forty-seven patients (38 males and 9 females) with previous aortic valve surgery have received reoperation on aorta from January 2003 to June 2012,and the mean interval time of re-intervention to aortic disease was 6 years ((6.0± 3.8) years).The secondary aortic surgery included aortic root replacement (14 cases),ascending aorta replacement (10 cases),aortic root/ascending aorta plus total arch replacement with stented elephant trunk implantation (21 cases),and total thoracoabdominal aorta replacement (2 cases).All these patients have received outpatient re-exams or follow-up by phone calls.Results After the initial aortic valve replacement,patients suffered from aortic dissection (25 cases,53%),ascending aortic aneurysm (12 cases,26%) or aortic root aneurysm (10 cases,21%).Diameter in ascending aorta increased (5.2±7.1) mm per year and aortic sinus (3.3±3.1) mm per year.The annual growth value of diameter in ascending aorta was higher in patients with rheumatic heart disease than that in Marfan syndrome (P<0.05).All 47 patients have received reoperation on aorta.One patient died in operating room because aortic dissection seriously involved right coronary artery.Seven patients had renal insufficiency after operation; neurological complications occurred in 14 patients including 7 patients with stroke and the others with transient brain dysfunction.All patients were followed up,the mean survival time was (97.25±17.63) months,95% confidence interval was 55.24-73.33 months.Eight cases were died during follow-up and five-year survival rate was 83%.Conclusion To reduce the aortic adverse events after first aortic valve surgery,it is necessary to actively treat and strictly

  20. Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve Disease

    DEFF Research Database (Denmark)

    Mylotte, Darren; Lefevre, Thierry; Søndergaard, Lars;

    2014-01-01

    .7%; type 1 BAV was 68.3%; and type 2 BAV was 5.0%. Multislice computed tomography (MSCT)-based TAV sizing was used in 63.5% of patients (77.1% balloon-expandable THV vs. 56.0% self-expandable THV, p = 0.02). Procedural mortality was 3.6%, with TAV embolization in 2.2% and conversion to surgery in 2.2%. The......BACKGROUND: Limited information exists describing the results of transcatheter aortic valve (TAV) replacement in patients with bicuspid aortic valve (BAV) disease (TAV-in-BAV). OBJECTIVES: This study sought to evaluate clinical outcomes of a large cohort of patients undergoing TAV-in-BAV. METHODS......: We retrospectively collected baseline characteristics, procedural data, and clinical follow-up findings from 12 centers in Europe and Canada that had performed TAV-in-BAV. RESULTS: A total of 139 patients underwent TAV-in-BAV with the balloon-expandable transcatheter heart valve (THV) (n = 48) or...

  1. Screening for Abdominal Aortic Aneurysm

    OpenAIRE

    Linné, Anneli

    2014-01-01

    Abdominal Aortic Aneurysm (AAA) is a common disease with a prevalence of 1.5-2.0% in 65-year old men in Sweden. The risk of having AAA is increased with smoking, high age, family history of AAA and cardiovascular disease. Women have a lower prevalence (0.5%) and develop AAA later in life. An AAA seldom gives any symptom prior to rupture. Untreated rupture is associated with 100% mortality, while surgically treated rupture is associated with 25-70% mortality. Prophylactic sur...

  2. Distinct sources of particles near the cusp and the dusk flank of the magnetosphere

    Czech Academy of Sciences Publication Activity Database

    Grison, Benjamin; Berchem, J.; Trattner, K.; Lavraud, B.; Pitout, F.; Souček, Jan; Richard, R.; Laakso, H.; Masson, A.; Dunlop, M.; Dandouras, I.; Reme, H.; Fazakerley, A.; Daly, P.

    San Francisco: American Geophysical Union, 2015. SM51D-2585. [AGU Fall Meeting 2015. 14.12.2015-18.12.2015, San Francisco] Institutional support: RVO:68378289 Keywords : magnetosphere * solar wind * magnetospheric cusps Subject RIV: BL - Plasma and Gas Discharge Physics https://agu.confex.com/agu/fm15/meetingapp.cgi/Paper/58429

  3. Implementation of a truncated cusp filter for real-time digital pulse processing in nuclear spectrometry

    International Nuclear Information System (INIS)

    In this work the transfer function for a truncated cusp infinite impulse response (IIR) filter has been derived. The truncated cusp filter, when given an exponential pulse in the presence of white noise, outputs a truncated cusp pulse which is optimum pulse shape under the constraint of finite pulse duration. However it features a pole outside of the unit-circle and is therefore inherently unstable. To overcome this instability a switching algorithm with two alternating poles has been applied. The filter has been simulated with MATLAB and Simulink and implemented on-board a FPGA. The pulses from a waveform generator and silicon drift detector (SDD) have been also processed by the filter and results compared with theory. We find that the simulation and measurements were in agreement and show that energy resolution due to electronic noise can be improved by up to 7.5% using a truncated cusp instead of triangular filter. An improvement of up to 2.8% in overall energy resolution was measured with a typical X-ray spectrometer based on a SDD detector with a nominal energy resolution of 150 eV at energies of MnKα line.

  4. The effect of extra dimensions on gravity wave bursts from cosmic string cusps

    International Nuclear Information System (INIS)

    We explore the kinematical effect of having extra dimensions on the gravitational wave emission from cosmic strings. Additional dimensions both round off cusps, and reduce the probability of their formation. We recompute the gravitational wave burst, taking into account these two factors, and find a potentially significant damping on the gravitational waves of the strings

  5. The core-cusp problem in cold dark matter halos and supernova feedback: effects of oscillation

    International Nuclear Information System (INIS)

    This study investigates the dynamical response of dark matter (DM) halos to recurrent starbursts in forming less-massive galaxies to solve the core-cusp problem. The gas, which is heated by supernova feedback after a starburst, expands and the star formation then terminates. This expanding gas loses energy by radiative cooling and then falls back toward the galactic center. Subsequently, the starburst is enhanced again. This cycle of expansion and contraction of the interstellar gas leads to a repetitive change in the gravitational potential of the gas. The resonance between DM particles and the density wave excited by the oscillating potential plays a key role in understanding the physical mechanism of the cusp-core transition of DM halos. DM halos effectively gain kinetic energy from the baryon potential through the energy transfer driven by the resonance between the particles and density waves. We determine that the critical condition for the cusp-core transition is such that the oscillation period of the gas potential is approximately the same as the local dynamical time of DM halos. We present the resultant core radius of a DM halo after the cusp-core transition induced by the resonance by using the conventional mass density profile predicted by the cold dark matter models. Moreover, we verify the analytical model by using N-body simulations, and the results validate the resonance model.

  6. Explaining health care utilization for panic attacks using cusp catastrophe modeling.

    Science.gov (United States)

    Katerndahl, David

    2008-10-01

    Despite increased health care utilization, patients with panic disorder continue to report unmet needs. The objective was to compare the fit of linear and Cusp Catastrophe Modeling in explaining changes in utilization of emergency, general and mental health settings, and self-treatments for panic symptoms. This community-based study surveyed 97 subjects with panic attacks drawn from a sample of randomly-selected adults from randomly-selected households. The stressor (splitting) variable used was Phobic Anxiety while predisposing variables included Family Health Care Utilization, Perceived Life Threat and Need For Treatment, and Treatment Experience. Outcomes consisted of the number of sites and self-treatments used for panic symptoms when first seeking care and during the 2 months prior to survey. Use of mental health sites and self-treatments demonstrated superior modeling with cusp catastrophe approaches using treatment experience as the predisposing variable, accounting for 47% and 38% of variances respectively, improving the fit by over 20% compared to the best linear models in both cases. Cusp catastrophe modeling accounted for more variance than all linear models when describing use of mental health settings and self-treatments. Cusp catastrophe may explain bimodal distributions in behavior, delays in behavior change, and sudden shifts in behavior in stressful situations. PMID:18765074

  7. On the Cusp of Cyberspace: Adolescents' Online Text Use in Conversation

    Science.gov (United States)

    Berg, Margaret A.

    2011-01-01

    This discourse analysis study examines the use of online texts in the live conversations of adolescents at and around computers in the Young Adult section of a Midwestern public library serving a diverse SES population. On the cusp of cyberspace, where online texts influence conversation and the conversation influences the creation of online…

  8. Under the sword of Damocles: plausible regeneration of dark matter cusps at the smallest galactic scales

    CERN Document Server

    Laporte, Chervin F P

    2014-01-01

    We run controlled N-body experiments to study the evolution of the dark matter (DM) halo profiles of dwarf galaxies driven by the accretion of DM substructures. Our initial conditions assume that supernova feedback erases the primordial DM cusps of haloes with $10^{9}-10^{10} \\rm{M_{\\odot}}$ at $z=0$. The orbits and masses of the infalling substructures are borrowed from the {\\it Aquarius} simulations. Our experiments show that a fraction of haloes that undergo 1:3 down to 1:30 mergers are susceptible to reform a DM cusp by $z\\approx 0$. Cusp regrowth is driven the accretion of DM substructures that are dense enough reach the central regions of the main halo before being tidally disrupted. The infall of substructures with a mass ratio above 1:6 on the mean of the reported mass-concentration relation systematically lead to cusp regrowth. Between 1:6 to 1:8, and 1:8 to 1:30 substructures need to be located one and two-sigma above the mean, respectively. The merging timescales of these dense, low-mass substructu...

  9. Synodontia With Talon Cusp – A Case Report And Review Of Literature

    Directory of Open Access Journals (Sweden)

    Deepinder Singh Duggal

    2011-07-01

    Full Text Available Synodontia or Fusion is more commonly seen in the anterior and maxillary region.. Fusion of a supernumerary tooth to one in the normal series is not an uncommon finding, but these anomalies in conjunction with a talon cusp form a rare case. The etiology, prevalence and clinical features of the aforementioned anomalies have been reviewed in detail.

  10. Swarm in situ observations of F region polar cap patches created by cusp precipitation

    CERN Document Server

    Goodwin, L V; Miles, D M; Patra, S; van der Meeren, C; Buchert, S C; Burchill, J K; Clausen, L B N; Knudsen, D J; McWilliams, K A; Moen, J

    2016-01-01

    High-resolution in situ measurements from the three Swarm spacecraft, in a string-of-pearls configuration, provide new insights about the combined role of flow channel events and particle impact ionization in creating $\\textit{F}$ region electron density structures in the northern Scandinavian dayside cusp. We present a case of polar cap patch formation where a reconnection-driven low-density relative westward flow channel is eroding the dayside solar-ionized plasma but where particle impact ionization in the cusp dominates the initial plasma structuring. In the cusp, density features are observed which are twice as dense as the solar-ionized background. These features then follow the polar cap convection and become less structured and lower in amplitude. These are the first in situ observations tracking polar cap patch evolution from creation by plasma transport and enhancement by cusp precipitation, through entrainment in the polar cap flow and relaxation into smooth patches as they approach the nightside a...

  11. Weak annihilation cusp inside the dark matter spike about a black hole

    Science.gov (United States)

    Shapiro, Stuart L.; Shelton, Jessie

    2016-06-01

    We reinvestigate the effect of annihilations on the distribution of collisionless dark matter (DM) in a spherical density spike around a massive black hole. We first construct a very simple, pedagogic, analytic model for an isotropic phase space distribution function that accounts for annihilation and reproduces the "weak cusp" found by Vasiliev for DM deep within the spike and away from its boundaries. The DM density in the cusp varies as r-1 /2 for s -wave annihilation, where r is the distance from the central black hole, and is not a flat "plateau" profile. We then extend this model by incorporating a loss cone that accounts for the capture of DM particles by the hole. The loss cone is implemented by a boundary condition that removes capture orbits, resulting in an anisotropic distribution function. Finally, we evolve an initial spike distribution function by integrating the Boltzmann equation to show how the weak cusp grows and its density decreases with time. We treat two cases, one for s -wave and the other for p -wave DM annihilation, adopting parameters characteristic of the Milky Way nuclear core and typical WIMP models for DM. The cusp density profile for p -wave annihilation is weaker, varying like ˜r-0.34, but is still not a flat plateau.

  12. Cusp-like singular soliton solutions of Jaulent-Miodek equation using symbolic computation

    International Nuclear Information System (INIS)

    In this paper, the sine-cosine method is employed to construct a series of exact solitary solutions to the celebrated Jaulent-Miodek equation. Solitons, anti-solitons and cusp-like singular solutions are obtained with the aid of symbolic computation.

  13. Structure of the high-altitude cusp formed by the horizontal IMF

    Czech Academy of Sciences Publication Activity Database

    Šimůnek, Jiří; Šafránková, J.; Němeček, Z.; Přech, L.

    2005-01-01

    Roč. 36, č. 10 (2005), s. 1928-1933. ISSN 0273-1177 R&D Projects: GA ČR(CZ) GA205/03/0953 Institutional research plan: CEZ:AV0Z30420517 Keywords : Interplanetary magnetic field * Magnetospheric cusp * Solar wind plasma * Magnetic reconnection Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.706, year: 2005

  14. Spectral estimates for Dirichlet Laplacians and Schrodinger operators on geometrically nontrivial cusps

    Czech Academy of Sciences Publication Activity Database

    Exner, Pavel; Barseghyan, Diana

    2013-01-01

    Roč. 3, č. 4 (2013), s. 465-484. ISSN 1664-039X R&D Projects: GA ČR GAP203/11/0701 Institutional support: RVO:61389005 Keywords : Dirichlet Laplacian * cusp-shaped region * Lieb-Thirring inequalities * bending and twisting Subject RIV: BE - Theoretical Physics

  15. Observations of vortex-like structure in the cusp-magnetosheath region during northward IMF orientation

    Directory of Open Access Journals (Sweden)

    O. Tkachenko

    2008-10-01

    Full Text Available Two-point observations made by the Interball spacecraft pair unveiled a presence of a large vortex-like structure filled by slow and heated plasma in the outer cusp during periods of the positive BZ interplanetary magnetic field (IMF component. We have observed the rotation of the magnetic field and the decrease of its magnitude connected with the presence of a hot plasma population inside the vortex. The structure starts with a clear reversal of the plasma flow caused by reconnection tailward of the cusp that turns a part of the magnetosheath plasma into the cusp. We compare the observations of two spacecraft in detail, discuss the differences between them and suggest the way of a formation such structure. Moreover, the statistical results have confirmed that this phenomenon is probably a regular feature of the high-altitude cusp, however, this relatively small structure cannot be observed too often. The alternative explanation of presented observations as a flapping of the magnetopause is taken into account and discussed.

  16. On the origin of ULF broadband electromagnetic fluctuations in the polar cusps

    Czech Academy of Sciences Publication Activity Database

    Grison, Benjamin; Cornilleau-Wehrlin, N.; Santolík, Ondřej

    Venice: CAA - ESA, 2015. [Cluster Workshop /25./. 12.10.2015–16.10.2015, Venice] Institutional support: RVO:68378289 Keywords : polar cusps * electromagnetic emissions * magnetosheath Subject RIV: BL - Plasma and Gas Discharge Physics http://caa.estec.esa.int/images/cluster_workshops/25/Cluster25_abstract_book4.pdf

  17. Prevalence of talon cusps in a Portuguese population: Forensic identification significance of a rare trait

    Directory of Open Access Journals (Sweden)

    Ricardo Jorge Simões

    2014-01-01

    Full Text Available Background: Dental techniques are frequently used in human identification; some of those include comparative analyses of dental features that, being rare or unique to an individual, can establish a positive identification. The usefulness of each feature depends on its population, frequency, and uniqueness. The aim of this study was to determine the prevalence of talon cusps in a Portuguese population. Materials and Methods: A prospective study was performed. Three hundred and two patients were studied, and talon cusps presence was assessed. Statistical tests were carried out using Statistical Package for the Social Sciences (SPSS 17 software (SPSS Inc., Chicago, IL, USA. Statistical analysis relied primarily on descriptive statistics and crosstabs, with Chi-square analysis. Results: Results showed that talon cusps were observed in only 6.3% of patients. The maxillary lateral incisors were the most common teeth showing this feature (82.1% of all teeth. Conclusion: It can be concluded that talon cusps are an uncommon trait in these Portuguese population, and therefore, it is a feature that can be potentially very useful in forensic human identification, when antemortem dental records are available.

  18. Prevalence of talon cusps in a Portuguese population: Forensic identification significance of a rare trait

    Science.gov (United States)

    Simões, Ricardo Jorge; Cardoso, Hugo F.V.; Caldas, Inês Morais

    2014-01-01

    Background: Dental techniques are frequently used in human identification; some of those include comparative analyses of dental features that, being rare or unique to an individual, can establish a positive identification. The usefulness of each feature depends on its population, frequency, and uniqueness. The aim of this study was to determine the prevalence of talon cusps in a Portuguese population. Materials and Methods: A prospective study was performed. Three hundred and two patients were studied, and talon cusps presence was assessed. Statistical tests were carried out using Statistical Package for the Social Sciences (SPSS) 17 software (SPSS Inc., Chicago, IL, USA). Statistical analysis relied primarily on descriptive statistics and crosstabs, with Chi-square analysis. Results: Results showed that talon cusps were observed in only 6.3% of patients. The maxillary lateral incisors were the most common teeth showing this feature (82.1% of all teeth). Conclusion: It can be concluded that talon cusps are an uncommon trait in these Portuguese population, and therefore, it is a feature that can be potentially very useful in forensic human identification, when antemortem dental records are available. PMID:24688559

  19. Dimension formula of cusp form spaces on half-spaces of quaternions

    Institute of Scientific and Technical Information of China (English)

    何峪; 陆洪文

    1999-01-01

    A dimension formula for the spaces of cusp forms defined on quaternionic half-spaces of degree two is obtained by Selberg trace formula, and the contributions of some conjugacy classes are calculated. Some results on the classification of the conjugacy classes of modular group are obtained.

  20. The Relationship between Victimization at School and Achievement: The Cusp Catastrophe Model for Reading Performance

    Science.gov (United States)

    Sideridis, Georgios D.; Antoniou, Faye; Stamovlasis, Dimitrios; Morgan, Paul L.

    2013-01-01

    We evaluated the relationship between victimization and academic achievement from a nonlinear perspective using a cusp catastrophe model. Participants were 62 students with identified learning disabilities (LD) using statewide criteria in Greece. Students participated in a 2-year cohort-sequential design. Reading assessments involved measures of…

  1. The core-cusp problem in cold dark matter halos and supernova feedback: effects of oscillation

    Energy Technology Data Exchange (ETDEWEB)

    Ogiya, Go; Mori, Masao, E-mail: ogiya@ccs.tsukuba.ac.jp [Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577 (Japan)

    2014-09-20

    This study investigates the dynamical response of dark matter (DM) halos to recurrent starbursts in forming less-massive galaxies to solve the core-cusp problem. The gas, which is heated by supernova feedback after a starburst, expands and the star formation then terminates. This expanding gas loses energy by radiative cooling and then falls back toward the galactic center. Subsequently, the starburst is enhanced again. This cycle of expansion and contraction of the interstellar gas leads to a repetitive change in the gravitational potential of the gas. The resonance between DM particles and the density wave excited by the oscillating potential plays a key role in understanding the physical mechanism of the cusp-core transition of DM halos. DM halos effectively gain kinetic energy from the baryon potential through the energy transfer driven by the resonance between the particles and density waves. We determine that the critical condition for the cusp-core transition is such that the oscillation period of the gas potential is approximately the same as the local dynamical time of DM halos. We present the resultant core radius of a DM halo after the cusp-core transition induced by the resonance by using the conventional mass density profile predicted by the cold dark matter models. Moreover, we verify the analytical model by using N-body simulations, and the results validate the resonance model.

  2. Enhancement of vacuum transmission of intense electron beam through cusp magnetic field using dielectric drift tubes

    Energy Technology Data Exchange (ETDEWEB)

    John, P.I.; Jain, K.K.

    1981-09-01

    A technique for improving the transmission of intense electron beams through cusp magnetic field in vacuum using dielectric drift tubes has been demonstrated. The plasma produced by the material of the dielectric tube increases the transmission efficiency by a factor of four over vacuum values. 15 references, 5 figures.

  3. Can Supermassive Black Holes alter Cold Dark Matter cusps through accretion?

    OpenAIRE

    Read, J. I.; Gilmore, G.

    2002-01-01

    We present some simple models to determine whether or not the accretion of cold dark matter by supermassive black holes is astrophysically important. Contrary to some claims in the literature, we show that supermassive black holes cannot significantly alter a power law density cusp via accretion, whether during mergers or in the steady state.

  4. EISCAT observations of plasma patches at sub-auroral cusp latitudes

    Directory of Open Access Journals (Sweden)

    J. Moen

    2006-09-01

    Full Text Available A sequence of 3 patches of high-density (1012 m−3 cold plasma on a horizontal scale-size of 300–700 km was observed near magnetic noon by the EISCAT VHF radar above Svalbard on 17 December 2001. The patches followed a trajectory towards the cusp inflow region. The combination of radar and all-sky observations demonstrates that the patches must have been segmented equatorward of the cusp/cleft auroral display, and hence their properties had not yet been influenced by cusp particle showers and electrodynamics on open flux tubes. The last patch in the sequence was intersected by radio tomography observations, and was found to be located adjacent to a broader region of the same high electron density further south. The patches occurred under moderately active conditions (Kp=3 and the total electron content (TEC of the high-density plasma was 45 TEC units. The train of patches appeared as a segmentation of the tongue of ionization. The sequence of patches occurred in association with a sequence of flow bursts in the dusk cell return flow. It is proposed that reconnection driven pulsed convection is able to create sub-auroral patches in the region where high density mid-latitude plasma is diverted poleward toward the cusp. It is the downward Birkeland current sheet located at the equatorward boundary of the flow disturbance that represents the actual cutting mechanism.

  5. Bicuspid Aortic Valve Disease and Ascending Aortic Aneurysms: Gaps in Knowledge

    Directory of Open Access Journals (Sweden)

    Katie L. Losenno

    2012-01-01

    Full Text Available The bicuspid aortic valve is the most common congenital cardiac anomaly in developed nations. The abnormal bicuspid morphology of the aortic valve results in valvular dysfunction and subsequent hemodynamic derangements. However, the clinical presentation of bicuspid aortic valve disease remains quite heterogeneous with patients presenting from infancy to late adulthood with variable degrees of valvular stenosis and insufficiency and associated abnormalities including aortic coarctation, hypoplastic left heart structures, and ascending aortic dilatation. Emerging evidence suggests that the heterogeneous presentation of bicuspid aortic valve phenotypes may be a more complex matter related to congenital, genetic, and/or connective tissue abnormalities. Optimal management of patients with BAV disease and associated ascending aortic aneurysms often requires a thoughtful approach, carefully assessing various risk factors of the aortic valve and the aorta and discerning individual indications for ongoing surveillance, medical management, and operative intervention. We review current concepts of anatomic classification, pathophysiology, natural history, and clinical management of bicuspid aortic valve disease with associated ascending aortic aneurysms.

  6. Modeling transverse heating and outflow of ionospheric ions from the dayside cusp/cleft. 2 Applications

    Directory of Open Access Journals (Sweden)

    M. Bouhram

    Full Text Available In this paper, we consider major ion energization mechanisms in the dayside cusp/cleft region. This includes transverse ion heating by ion cyclotron resonance (ICR, ion energization through structures of field-aligned electric potential drops, and transverse heating by lower hybrid (LH waves. First, we present and discuss three typical cusp/cleft crossings associated with one of the first two mechanisms mentioned above. Then, we develop a procedure for finding the altitude dependence of ICR heating for any data set in the high-altitude cusp/cleft under the absence of field-aligned potential drops. This has been accomplished using a large set of numerical simulations from a two-dimensional, steady-state, Monte Carlo, trajectory-based code, as discussed in detail in the first companion paper (Bouhram et al., 2003. The procedure is applied and tested successfully for the first two events, by using patterns of ion moments along the satellite track as constraints. Then, we present a statistical study that uses 25 cusp/cleft crossings associated with steady IMF conditions, where ICR heating is expected to occur alone. It is pointed out that the ICR heating increases gradually versus geocentric distance as s 3.3 ± 1.8 . The inferred values of the wave power and the spectral index associated with the component responsible for ICR heating are lower than those characterizing the broad-band, extremely low-frequency (BBELF turbulence usually observed in the cusp/cleft. This strengthens the idea that more than one wave-mode is contained in the BBELF turbulence, and only a small fraction of the observed turbulence is responsible for ICR heating. Then, we study the occurrence versus magnetic local time (MLT of field-aligned potential drops. According to previous statistical studies, such structures are not common in the cusp and tend to be associated with the cleft region. We also discuss the effects of LH heating in the cusp on the observed ion distributions

  7. Giant Thoracic Aneurysm Following Valve Replacement for Bicuspid Aortic Valve.

    Science.gov (United States)

    Tran, Cao; Ul Haq, Ehtesham; Nguyen, Ngoc; Omar, Bassam

    2015-01-01

    Bicuspid aortic valve is a common congenital anomaly associated with aortopathy, which can cause aortic root dilatation, necessitating regular screening if the aortic root is > 4.0 cm. Despite the low absolute incidence of aortic complications associated with bicuspid aortic valve in the general population, the consequences of such complications for an individual patient can be devastating. Herein we propose a balanced algorithm that incorporates recommendations from the three major guidelines for follow-up imaging of the aortic root and ascending thoracic aorta in patients with a bicuspid aortic valve, maintaining the current recommendations with regard to surgical thresholds. PMID:26827748

  8. Low and middle altitude cusp particle signatures for general magnetopause reconnection rate variations. 1: Theory

    Science.gov (United States)

    Lockwood, M.; Smith, M. F.

    1994-01-01

    We present predictions of the signatures of magnetosheath particle precipitation (in the regions classified as open low-latitude boundary layer, cusp, mantle and polar cap) for periods when the interplanetary magnetic field has a southward component. These are made using the 'pulsating cusp' model of the effects of time-varying magnetic reconnection at the dayside magnetopause. Predictions are made for both low-altitude satellites in the topside ionosphere and for midaltitude spacecraft in the magnetosphere. Low-altitude cusp signatures, which show a continuous ion dispersion signature, reveal 'quasi-steady reconnection' (one limit of the pulsating cusp model), which persists for a period of at least 10 min. We estimate that 'quasi-steady' in this context corresponds to fluctuations in the reconnection rate of a factor of 2 or less. The other limit of the pulsating cusp model explains the instantaneous jumps in the precipitating ion spectrum that have been observed at low altitudes. Such jumps are produced by isolated pulses of reconnection: that is, they are separated by intervals when the reconnection rate is zero. These also generate convecting patches on the magnetopause in which the field lines thread the boundary via a rotational discontinuity separated by more extensive regions of tangential discontinuity. Predictions of the corresponding ion precipitation signatures seen by midaltitude spacecraft are presented. We resolve the apparent contradiction between estimates of the width of the injection region from midaltitude data and the concept of continuous entry of solar wind plasma along open field lines. In addition, we reevaluate the use of pitch angle-energy dispersion to estimate the injection distance.

  9. Quadricuspid aortic valve with ruptured sinus of Valsalva.

    Science.gov (United States)

    Akerem Khan, Shamruz Khan; Tamin, Syahidah Syed; Burkhart, Harold M; Araoz, Philip A; Young, Phillip M

    2013-02-01

    We present a case of a 24-year-old woman who was diagnosed with quadricuspid aortic valve with ruptured sinus of Valsalva. Quadricuspid aortic valve is a rare congenital cardiac anomaly. The recognition of quadricuspid aortic valve has clinical significance as it causes aortic valve dysfunction, and is often associated with other congenital cardiac abnormalities. We showed the important role of multimodality imaging in diagnosing a quadricuspid aortic valve associated with ruptured sinus of Valsalva. PMID:22874066

  10. Imaging of thoracic aortic dissection

    International Nuclear Information System (INIS)

    Acute thoracic aortic dissection has a high mortality rate if untreated, so the diagnosis must be rapidly made. Multiple imaging techniques are often used. This retrospective study from 1988 to 1993 assesses the usefulness in diagnosis of chest X-rays, computed tomography (CT) scanning, aortography, magnetic resonance imaging (MRI), trans-thoracic (TTE) and trans-oesophageal (TOE) echocardiography. Forty-two patients with a final clinical diagnosis of dissection were studied. The diagnosis was confirmed in 16 (13 at surgery and three at autopsy). Three died with dissection given as the only cause of death. Chest X-ray abnormalities were seen in all 19 patients with surgery or death from dissection, with a widened mediastinum and/or dilated aorta being present in 17. In the group of 16 patients with surgery or autopsy proof, CT scans found dissections in 9 out of 12 patients studied and correctly classified the type in only five. Aortography was preformed in five, with accurate depiction of dissection and type in all. TTE found dissections in three of eight patients imaged by this method. MRI and TOE were preformed each on two patients, with accurate depiction of dissection and type in each. Because of the relatively low sensitivity of CT scanning in defining aortic dissections Westmead Hospital is currently assessing the use of TOE as the prime imaging modality prior to surgical intervention. 17 refs., 4 tabs., 4 figs

  11. Extended field chemoradiation for cervical cancer patients with histologically proven para-aortic lymph node metastases after laparoscopic lymphadenectomy

    International Nuclear Information System (INIS)

    The purpose of this work was to evaluate the use of extended-field chemoradiation (EFRT) with concomitant chemotherapy in patients with histologically confirmed para-aortic metastases after laparoscopic para-aortic and pelvic lymphadenectomy (LAE) with regard to oncologic results and treatment-related toxicity. A total of 44 women with squamous cell carcinoma (82 %) and adenocarcinoma (18 %) of the cervix in FIGO stages IIA (n = 3), IIB (n = 29); IIIB (n = 9), and IVA (n = 3) and histologically proven para-aortic metastases underwent EFRT and chemotherapy. Laparoscopic LAE was performed in 40 patients. Patients underwent chemoradiation with conventional fractionation of 1.8-50.4 Gy to the para-aortic and pelvic region. In addition, MRI-guided brachytherapy was performed to the cervix with 5-6 single doses of 5 Gy for a total dose of 25-30 Gy. The mean number of harvested lymph nodes was 17 in the pelvic as well as para-aortic regions, respectively. Laparoscopic intervention did not delay chemoradiation. Follow-up was 6-76 months (mean 25.1 months). There was no grade 4 or 5 acute radiation toxicity. In all, 8, 4, and 11 % grade 1, 2, and 3 gastrointestinal late toxicities and 7, 11, and 19 % grade 1, 2 and 3 genitourinary late toxicities were recorded. Despite the excellent locoregional (pelvic) control rates of 89.1 and 82.8 % after 2 and 5 years, respectively, the overall survival rates were 68.4 and 54.1 % after 2 and 5 years, respectively. Of the 44 patients, 43 remained tumor free in the para-aortic region. In patients with proven para-aortic disease, excellent pelvic and para-aortic control could be achieved by laparoscopic LAE followed by EFRT. More than half of the patients were long-term survivors. The high risk of distant metastases should be addressed by further improving systemic treatment. (orig.)

  12. Aortic reconstruction with bovine pericardial grafts

    Directory of Open Access Journals (Sweden)

    Silveira Lindemberg Mota

    2003-01-01

    Full Text Available INTRODUCTION: Glutaraldehyde-treated crimped bovine pericardial grafts are currently used in aortic graft surgery. These conduits have become good options for these operations, available in different sizes and shapes and at a low cost. OBJECTIVE:To evaluate the results obtained with bovine pericardial grafts for aortic reconstruction, specially concerning late complications. METHOD: Between January 1995 and January 2002, 57 patients underwent different types of aortic reconstruction operations using bovine pericardial grafts. A total of 29 (50.8% were operated on an urgent basis (mostly acute Stanford A dissection and 28 electively. Thoracotomy was performed in three patients for descending aortic replacement (two patients and aortoplasty with a patch in one. All remaining 54 underwent sternotomy, cardiopulmonary bypass and aortic resection. Deep hypothermia and total circulatory arrest was used in acute dissections and arch operations. RESULTS: Hospital mortality was 17.5%. Follow-up was 24.09 months (18.5 to 29.8 months confidence interval and complication-free actuarial survival curve was 92.3% (standard deviation ± 10.6. Two patients lately developed thoracoabdominal aneurysms following previous DeBakey II dissection and one died from endocarditis. One "patch" aortoplasty patient developed local descending aortic pseudoaneurysm 42 months after surgery. All other patients are asymptomatic and currently clinically evaluated with echocardiography and CT scans, showing no complications. CONCLUSION: Use of bovine pericardial grafts in aortic reconstruction surgery is adequate and safe, with few complications related to the conduits.

  13. Valvular Aortic Stenosis: A Proteomic Insight

    Directory of Open Access Journals (Sweden)

    Fernando Vivanco

    2010-02-01

    Full Text Available Calcified aortic valve disease is a slowly progressive disorder that ranges from mild valve thickening with no obstruction of blood flow, known as aortic sclerosis, to severe calcification with impaired leaflet motion or aortic stenosis. In the present work we describe a rapid, reproducible and effective method to carry out proteomic analysis of stenotic human valves by conventional 2-DE and 2D-DIGE, minimizing the interference due to high calcium concentrations. Furthermore, the protocol permits the aortic stenosis proteome to be analysed, advancing our knowledge in this area. Summary: Until recently, aortic stenosis (AS was considered a passive process secondary to calcium deposition in the aortic valves. However, it has recently been highlighted that the risk factors associated with the development of calcified AS in the elderly are similar to those of coronary artery disease. Furthermore, degenerative AS shares histological characteristics with atherosclerotic plaques, leading to the suggestion that calcified aortic valve disease is a chronic inflammatory process similar to atherosclerosis. Nevertheless, certain data does not fit with this theory making it necessary to further study this pathology. The aim of this study is to develop an effective protein extraction protocol for aortic stenosis valves such that proteomic analyses can be performed on these structures. In the present work we have defined a rapid, reproducible and effective method to extract proteins and that is compatible with 2-DE, 2D-DIGE and MS techniques. Defining the protein profile of this tissue is an important and challenging task that will help to understand the mechanisms of physiological/pathological processes in aortic stenosis valves.

  14. Open surgical repair of abdominal aortic aneurysm: Proximal aortic control by endoaortic balloon - A novel approach

    OpenAIRE

    Balakrishnan Soundaravalli; Palaniappan, M.; Rajani Sundar; Chandrasekar, P.

    2012-01-01

    Patients with infrarenal abdominal aortic aneurysm with unfavorable anatomy for endovascular aneurysm repair have to undergo open surgical repair. Open surgery has its own morbidity in terms of proximal clamping and declamping, bleeding and prolonged hospital stay and mortality. We present two such patients with juxtarenal abdominal aortic aneurysm who underwent open surgical repair. The proximal aortic control during open surgical repair of the aneurysm was achieved by endoaortic balloon occ...

  15. Open surgical repair of abdominal aortic aneurysm: Proximal aortic control by endoaortic balloon - A novel approach

    Directory of Open Access Journals (Sweden)

    Balakrishnan Soundaravalli

    2012-01-01

    Full Text Available Patients with infrarenal abdominal aortic aneurysm with unfavorable anatomy for endovascular aneurysm repair have to undergo open surgical repair. Open surgery has its own morbidity in terms of proximal clamping and declamping, bleeding and prolonged hospital stay and mortality. We present two such patients with juxtarenal abdominal aortic aneurysm who underwent open surgical repair. The proximal aortic control during open surgical repair of the aneurysm was achieved by endoaortic balloon occlusion technique.

  16. First transcatheter aortic valve implantation for severe pure aortic regurgitation in Asia

    OpenAIRE

    Chiam, Paul Toon-Lim; Ewe, See Hooi; Chua, Yeow Leng; Lim, Yean Teng

    2014-01-01

    Transcatheter aortic valve implantation (TAVI) has become the standard of care for inoperable patients with symptomatic severe aortic stenosis (AS), and an alternative to open aortic valve replacement for patients at high surgical risk. TAVI has also been performed in several groups of patients with off-label indications such as severe bicuspid AS, and as a valve-in-valve therapy for a degenerated surgical bioprosthesis. Although TAVI with CoreValve® prosthesis is technically challenging, and...

  17. Anatomics Knowledges of Aortic Root in the Transcatheter Aortic Valve Implantation.

    OpenAIRE

    Marcelo Cerezo; Omar Bertani; Gisela Panciroli; Sebastián Duhalde; Karina Ferreira; Luciano Honaine

    2010-01-01

    The Aortic Valve is a valvular system that bears different high pressure forces. It takes part of a complex structure called Aortic Root. Nowadays, anatomic knowledge has taken a preponderant role, due to the use of the Transcatether Aortic Valve Implant (TAVI). To describe the patient´s characteristics which exclude them of the TAVI for anatomic reasons in cadaveric dissections and transthoracic echocardiograms. A descriptive retrospective analysis of 67 individuals was performed and divided...

  18. Emergency Transcatheter Aortic Valve Implantation for Acute and Early Failure of Sutureless Perceval Aortic Valve.

    Science.gov (United States)

    Durand, Eric; Tron, Christophe; Eltchaninoff, Hélène

    2015-09-01

    We report the case of a 78-year-old woman admitted for cardiogenic shock related to acute and early failure (severe aortic regurgitation) of a Perceval sutureless aortic bioprosthesis (Sorin Group, Saluggia, Italy). Clinical stability was achieved using rescue transfemoral transcatheter aortic valve-in-valve implantation with an Edwards SAPIEN 3 prosthesis (Edwards Lifesciences, Irvine, CA). To our knowledge, we report herein the first case of successful valve-in-valve implantation using a SAPIEN 3 transcatheter heart valve in a sutureless bioprosthetic aortic valve with acute and early deterioration. PMID:26095935

  19. Left ventricular diastolic function in valvular aortic stenosis after aortic valve replacement

    Directory of Open Access Journals (Sweden)

    Ristić-Anđelkov Anđelka

    2002-01-01

    Full Text Available In adults with significant sympthomatic aortic valve stenosis, aortic valve replacement is therapy of choice. Replacement of the diseased aortic valve with a prosthetic valve yields relief of left ventricular outflow obstruction. Myocardial remodeling with regression of mass transpires as the heart adapts to the new level of after load. In patients with moderate left ventricular hypertrophy improvement in diastolic function during the first year after aortic valve replacement is visible, while in patients with extreme myocardial hypertrophic changes it was slower.

  20. Stroke Volume estimation using aortic pressure measurements and aortic cross sectional area: Proof of concept.

    Science.gov (United States)

    Kamoi, S; Pretty, C G; Chiew, Y S; Pironet, A; Davidson, S; Desaive, T; Shaw, G M; Chase, J G

    2015-08-01

    Accurate Stroke Volume (SV) monitoring is essential for patient with cardiovascular dysfunction patients. However, direct SV measurements are not clinically feasible due to the highly invasive nature of measurement devices. Current devices for indirect monitoring of SV are shown to be inaccurate during sudden hemodynamic changes. This paper presents a novel SV estimation using readily available aortic pressure measurements and aortic cross sectional area, using data from a porcine experiment where medical interventions such as fluid replacement, dobutamine infusions, and recruitment maneuvers induced SV changes in a pig with circulatory shock. Measurement of left ventricular volume, proximal aortic pressure, and descending aortic pressure waveforms were made simultaneously during the experiment. From measured data, proximal aortic pressure was separated into reservoir and excess pressures. Beat-to-beat aortic characteristic impedance values were calculated using both aortic pressure measurements and an estimate of the aortic cross sectional area. SV was estimated using the calculated aortic characteristic impedance and excess component of the proximal aorta. The median difference between directly measured SV and estimated SV was -1.4ml with 95% limit of agreement +/- 6.6ml. This method demonstrates that SV can be accurately captured beat-to-beat during sudden changes in hemodynamic state. This novel SV estimation could enable improved cardiac and circulatory treatment in the critical care environment by titrating treatment to the effect on SV. PMID:26736434

  1. The role of aortic wall CT attenuation measurements for the diagnosis of acute aortic syndromes

    International Nuclear Information System (INIS)

    Objectives: To determine if measurements of aortic wall attenuation can improve the CT diagnosis of acute aortic syndromes. Methods: CT reports from a ten year period were searched for acute aortic syndromes (AAS). Studies with both an unenhanced and a contrast enhanced (CTA) series that had resulted in the diagnosis of intramural hematoma (IMH) were reviewed. Diagnoses were confirmed by medical records. The attenuation of aortic wall abnormalities was measured. The observed attenuation threshold was validated using studies from 39 new subjects with a variety of aortic conditions. Results: The term “aortic dissection” was identified in 1206, and IMH in 124 patients’ reports. IMH was confirmed in 31 patients, 21 of whom had both unenhanced and contrast enhanced images. All 21 had pathologic CTA findings, and no CTA with IMH was normal. Attenuation of the aortic wall was greater than 45 HUs on the CTA images in all patients with IMH. When this threshold was applied to the new group, sensitivity for diagnosing AAS was 100% (19/19), and specificity 94% (16/17). Addition of unenhanced images did not improve accuracy. Conclusions: Measurements of aortic wall attenuation in CTA have a high negative predictive value for the diagnosis of acute aortic syndromes

  2. Drag reduction of high altitude airships by active boundary layer control. Effect of a cusp on the reduction; Nodo kyokaiso seigyo ni yoru koso hikosen no teiko teigen. Cusp ni yoru teigen koka

    Energy Technology Data Exchange (ETDEWEB)

    Yamamura, N. [Nissan Motor Co. Ltd., Tokyo (Japan); Matsuuchi, K.; Yamazaki, S.; Sasaki, A. [University of Tsukuba, Tsukuba (Japan); Onda, M. [Mechanical Engineering Lab., Tokyo (Japan)

    1998-02-25

    The aerodynamic character of station-keeping airships at high Reynolds numbers is examined. The boundary layer developing on the surface is sucked by an axial flow fan through a slot located at the rear part of the airship and the sucked gas is blown out as a jet. To know the effect of the cusp two models with and without a cusp attached to the inlet of the suction slot were used. The flow field near the inlet, in particular the pressure on the surface, was measured as the suction discharge was varied. We obtained the form drag by integrating the pressure distribution in a wide range of Reynolds number and of suction discharge. Taking into account the jet thrust and the calculated friction drag, we finally determined the total drag and evaluated the role of the cusp. It was found that the cusp plays an efficient role in reducing the drag. 7 refs., 12 figs.

  3. Medical image of the week: aortic ring

    Directory of Open Access Journals (Sweden)

    Wong C

    2014-10-01

    Full Text Available No abstract available. Article truncated after 150 words. A 78 year old man presented with altered mental status and was found to have an intraventricular hemorrhage. He was intubated for airway protection. On the post-intubation chest radiograph (Figure 1, the patient was noted to have a widening of the right paratracheal stripe. A CT chest (Figure 2 was obtained to characterize this finding and revealed an aortic ring which encircles the trachea and esophagus. Vascular rings are uncommon congenital abnormalities, accounting for approximately 1% of congenital heart disease. Complete vascular rings can occur with a right aortic arch with a ligamentum arteriosum or with a double aortic arch, such as with our patient (1. This ring can cause airway compression, stridor, esophageal compression, or no symptoms at all. As the embryo develops, the left fourth pharyngeal arch normally persists to become the aortic arch while the right fourth pharyngeal arch regresses. If both fourth pharyngeal arches persist, a ...

  4. Congenital anomalies of aortic arch: CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Yung; Kim, Yang Min; Kim, Tae Hoon; Kim, Mi Young [Sejong General hospial, Seoul (Korea, Republic of); Lee, Jae Young [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of); Kim, Hyung Seok [Cheju Medical Center, Cheju (Korea, Republic of)

    2001-01-01

    Aortic arch anomalies result from the failure of an embryonic vascular structure to persists and regress in the usual manner during formation of the aortic arch. The anomalous aortic arch may encircle and compress the trachea and esophagus as a form of a vascular ring. The diagnosis of aortic arch anomaly and the recognition of airway compression are important because they are conditions which complicate the natural and surgical course of related diseases. CT can demonstrate the nature of anatomic structures such as thr treachea and esophagus not revealed by angiogrphy, simultaneosuly disclosing the relationship of stenotic airways and offending mediastinal vessels. Volumetric data acquisition by means of spiral CT enables three dimensional reconstruction, which can provide easy global understanding for the complex anatomy and spatial relationship of airway and cardiovascular structures. Three dimensional imaging is very useful for the physician and surgeon who are not accustomed to mentally reconstructing axial images, and can facilitate surgical planning.

  5. A rare cause of recurrent aortic dissection.

    Science.gov (United States)

    Agrawal, Yashwant; Gupta, Vishal

    2016-07-01

    We report the case of a 19-year-old man with a history of Loeys-Dietz syndrome (LDS), which was diagnosed when he had a Stanford type A aortic dissection. He also had multiple aneurysms including ones in the innominate, right common carotid, and right internal mammary arteries. He had had multiple procedures including Bentall's procedure, repeat sternotomy with complete arch and valve replacement, and coil embolization of internal mammary artery aneurysm in the past. His LDS was characterized by gene mutation for transforming growth factor-β receptor 1. He presented to our facility with sudden onset of back pain, radiating to the right shoulder and chest. He was diagnosed with Stanford type B aortic dissection and underwent thoracic aorta endovascular repair for his aortic dissection. This case represents the broad spectrum of pathology associated with LDS where even with regular surveillance and aggressive medical management the patient developed Stanford B aortic dissection. PMID:27358537

  6. Dissecting aortic aneurysm in maintenance hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Ounissi M

    2009-01-01

    Full Text Available The dissecting aortic aneurysm (DAA is a rare pathology that may result in fatal outcome. We report follow up of three cases of DAA patients undergoing maintenance hemo-dialysis who were managed conservatively.

  7. A rare cause of recurrent aortic dissection

    Directory of Open Access Journals (Sweden)

    Yashwant Agrawal

    2016-07-01

    Full Text Available We report the case of a 19-year-old man with a history of Loeys–Dietz syndrome (LDS, which was diagnosed when he had a Stanford type A aortic dissection. He also had multiple aneurysms including ones in the innominate, right common carotid, and right internal mammary arteries. He had had multiple procedures including Bentall’s procedure, repeat sternotomy with complete arch and valve replacement, and coil embolization of internal mammary artery aneurysm in the past. His LDS was characterized by gene mutation for transforming growth factor-β receptor 1. He presented to our facility with sudden onset of back pain, radiating to the right shoulder and chest. He was diagnosed with Stanford type B aortic dissection and underwent thoracic aorta endovascular repair for his aortic dissection. This case represents the broad spectrum of pathology associated with LDS where even with regular surveillance and aggressive medical management the patient developed Stanford B aortic dissection.

  8. CT diagnosis of aortic graft infections

    International Nuclear Information System (INIS)

    Two cases of aortic graft infections diagnosed by computed tomography (CT) are presented. CT scans demonstrated a zone of low attenuation in the perigraft area, in one case with a rim enhancement. The diagnoses were verfied by operation. (orig.)

  9. Surveillance intervals for small abdominal aortic aneurysms

    DEFF Research Database (Denmark)

    Bown, Matthew J; Sweeting, Michael J; Brown, Louise C;

    2013-01-01

    Small abdominal aortic aneurysms (AAAs [3.0 cm-5.4 cm in diameter]) are monitored by ultrasound surveillance. The intervals between surveillance scans should be chosen to detect an expanding aneurysm prior to rupture....

  10. Aortic aneurysm secondary to umbilical artery catheterization

    International Nuclear Information System (INIS)

    A 14-month-girl presented with an asymptomatic posterior mediastinal mass. She had a history of prematurity, umbilical artery catheterization, and sepsis. The diagnosis of aortic aneurysm was made by dynamic computed tomography. The aneurysm was successfully resected. (orig.)

  11. Anesthetic management of transcatheter aortic valve implantation

    OpenAIRE

    Annalisa Franco; Chiara Gerli; Laura Ruggeri; Fabrizio Monaco

    2012-01-01

    Transcatheter aortic valve implantation (TAVI) is an emergent technique for high-risk patients with aortic stenosis. TAVI poses significant challenges about its management because of the procedure itself and the population who undergo the implantation. Two devices are currently available and marketed in Europe and several other technologies are being developed. The retrograde transfemoral approach is the most popular procedure; nevertheless, it may not be feasible in patients with significant ...

  12. Navigation Technology in Endovascular Aortic Repair

    OpenAIRE

    Manstad-Hulaas, Frode

    2013-01-01

    A number of diseases can affect the aorta, and endovascular (minimally invasive) techniques can be used to treat many of these conditions. During endovascular aortic repair, different instruments, such as catheters (plastic tubes), metal wires and balloons are visualized by X-rays. Intermittent aortic injections of contrast medium improve the depiction of the aorta; however, contrast medium may damage kidney function in some patients, radiation can be harmful and X-ray images are 2- dimension...

  13. Effect of age on aortic atherosclerosis

    Institute of Scientific and Technical Information of China (English)

    Michael A. Chen; Miwa Kawakubo; Patrick M. Colletti; Dongxiang Xu; Laurie LaBree Dustin; Robert Detrano; Stanley P Azen; Nathan D. Wong; Xue-Qiao Zhao

    2013-01-01

    Objective To examine the association of atherosclerosis burden in the survivors of an asymptomatic elderly cohort study and its relationship to other coronary risk factors (specifically, age) by evaluating aortic atherosclerotic wall burden by magnetic resonance imaging (MRI). Methods A total of 312 participants in an ongoing observational cohort study underwent cardiac and descending thoracic aorta imaging by MRI. Maximum wall thickness was measured and the mean wall thickness calculated. Wall/outer wall ratio was used as a normalized wall index (NWI) adjusted for artery size difference among participants. Percent wall volume (PWV) was calculated as NWI × 100. Results In this asymptomatic cohort (mean age: 76 years), the mean (SD) aortic wall area and wall thickness were 222 ± 45 mm2 and 2.7 ± 0.4 mm, respectively. Maximum wall thickness was 3.4 ± 0.6 mm, and PWV was 32% ± 4%. Women appeared to have smaller wall area, but after correcting for their smaller artery size, had significantly higher PWV than men (P = 0.03). Older age was associated with larger wall area (P = 0.04 for trend) with similar PWVs. However, there were no statistically significant associations between standard risk factors, Framingham global risk, or metabolic syndrome status, therapy for cholesterol or hypertension, coronary or aortic calcium score, and the aortic wall burden. Aortic calcification was associated with coronary calcification. Conclusions Asymptomatic elderly in this cohort had a greater descending thoracic aortic wall volume that correlated with age, and women had a significantly increased PWV compared to men. In these survivors, the atherosclerotic aortic wall burden was not significantly associated with traditional risk factors or with coronary or aortic calcium scores or coronary calcium progression. Results suggest that age, or as yet unidentified risk factor(s), may be responsible for the increase in atherosclerosis.

  14. Glucose Suppresses Biological Ferroelectricity in Aortic Elastin

    OpenAIRE

    Liu, Yuanming; WANG, YUNJIE; Chow, Ming-Jay; Chen, Nataly Q.; Ma, Feiyue; Zhang, Yanhang; Li, Jiangyu

    2013-01-01

    Elastin is an intriguing extracellular matrix protein present in all connective tissues of vertebrates, rendering essential elasticity to connective tissues subjected to repeated physiological stresses. Using piezoresponse force microscopy, we show that the polarity of aortic elastin is switchable by an electrical field, which may be associated with the recently discovered biological ferroelectricity in the aorta. More interestingly, it is discovered that the switching in aortic elastin is la...

  15. Aortic dissection. Basic aspects and endovascular management

    International Nuclear Information System (INIS)

    Treatment of thoracic aortic pathology is complicated by the morbidity associated to the surgical procedure and to the frailty of an elderly and difficult population. Surgical operation in this kind of population frequently bears a significant incidence of death and long-term disability. In an effort to reduce the incidence of negative outcomes, minimally invasive techniques in the form of endovascular stenting have been introduced during the past decade. The technology, originally described by Parodi, and initially designed for its use in abdominal aortic aneurysms, has been adapted for the treatment of thoracic aortic aneurysms. Furthermore, an improved understanding of the pathophysiology and the natural history of thoracic aortic disease as well as the analysis of the outcomes have facilitated our treatment decisions in terms of the timing for an appropriate intervention. Treatment of thoracic aortic dissection using endovascular Stent is one of the more recent advances in this condition and is receiving increasing attention, as it is a less invasive alternative to an open surgical repair. Although this technology is still innovative, significant improvements have been made lately in the design and deployment of the endovascular Stent-grafts. These prostheses have been increasingly used to treat aneurysms, dissections and traumatic ruptures, as well as giant penetrating ulcers and intramural hematomas of the descending thoracic aorta with good early and mid-term outcomes. The rareness, complexity and severity of the pathology and the theoretically high risk of complications should render the surgeon extremely cautious especially with young patients. Conceptually, the endo luminal treatment in the acute phase seems to be the solution and will probably become a preferred therapy while technical refinement is under way. Worldwide experience is growing and with this a better understanding of the indications and limitations of this innovative therapy will be

  16. Letter to the EditorA statistical study of the location and motion of the HF radar cusp

    OpenAIRE

    Yeoman, T. K.; Hanlon, P. G.; K. A. McWilliams

    2002-01-01

    The large-scale and continuous monitoring of the ionospheric cusp region offered by HF radars has been exploited in order to examine the statistical location and motion of the equatorward edge of the HF radar cusp as a function of the upstream IMF BZ component. Although a considerable scatter is seen, both parameters have a clear influence from the north-south component of the IMF. Excellent agreement is achieved with previous observations from low altitude spacecraft ...

  17. The polar cusp: Particle-, optical- and geomagnetic manifistations of solar wind - magnetosphere interaction

    International Nuclear Information System (INIS)

    In this study observations of particle precipitation, optical emissions and geomagnetic disturbances associated with the low-altitude polar cusp are presented. The main observational basis is photometer data from two stations on Svalbard (Spitsbergen), Norway. These data have been used to map the location and dynamics of polar cusp auroras. One event with coordinated observations of low-energy precipitation from satellite HILAT and optical observations from the ground is discussed. Simultaneous photometer observations of the midday (Svalbard) and midnight (Alaska) sectors of the auroral oval are also presented. Thus, dynamical auroral phenomena with different temporal and spatial scales are investigated in relation to the interplanetary magnetic field and magnetospheric substorms. Certain large- and small-scale dynamics of the aurora and the geomagnetic field are shown to be consistent with the quasi steady-state/large-scale and impulsive/small-scale modes of magnetic reconnection at the frontside magnetopause

  18. Isoresonant conformal surfaces with cusps and boundedness of the relative determinant

    CERN Document Server

    D, Clara L Aldana

    2010-01-01

    We study the isoresonance problem on non-compact surfaces of finite area that are hyperbolic outside a compact set. Inverse resonance problems correspond to inverse spectral problems in the non-compact setting. We consider a conformal class of surfaces with hyperbolic cusps where the deformation takes place inside a fixed compact set. Inside this compactly supported conformal class we consider isoresonant metrics, i.e. metrics for which the set of resonances is the same, including multiplicities. We prove that sets of isoresonant metrics inside the conformal class are sequentially compact. We use relative determinants, splitting formulae for determinants and the result of B. Osgood, R. Phillips and P. Sarnak about compactness of sets of isospectral metrics on closed surfaces. In the second part, we study the relative determinant of the Laplace operator on a hyperbolic surface as function on the moduli space. We consider the moduli space of hyperbolic surfaces of fixed genus and fixed number of cusps. We consi...

  19. Surprises from the resummation of ladders in the ABJ(M) cusp anomalous dimension

    Science.gov (United States)

    Bonini, Marisa; Griguolo, Luca; Preti, Michelangelo; Seminara, Domenico

    2016-05-01

    We study the cusp anomalous dimension in mathcal{N} = 6 ABJ(M) theory, identifying a scaling limit in which the ladder diagrams dominate. The resummation is encoded into a Bethe-Salpeter equation that is mapped to a Schroedinger problem, exactly solvable due to the surprising supersymmetry of the effective Hamiltonian. In the ABJ case the solution implies the diagonalization of the U( N ) and U( M ) building blocks, suggesting the existence of two independent cusp anomalous dimensions and an unexpected exponentiation structure for the related Wilson loops. While consistent with previous perturbative analysis, the strong coupling limit of our result does not agree with the string theory computation, emphasizing a difference with the analogous resummation in the mathcal{N} = 4 case.

  20. Cusps of the K\\"ahler moduli space and stability conditions on K3 surfaces

    CERN Document Server

    Hartmann, Heinrich

    2010-01-01

    In [Ma1] S. Ma established a bijection between Fourier--Mukai partners of a K3 surface and cusps of the K\\"ahler moduli space. The K\\"ahler moduli space can be described as a quotient of Bridgeland's stability manifold. We study the relation between stability conditions $\\sigma$ near to a cusp and the associated Fourier--Mukai partner Y in the following ways. (1) We compare the heart of $\\sigma$ to the heart of coherent sheaves on Y. (2) We construct Y as moduli space of $\\sigma$-stable objects. An appendix is devoted to the group of auto-equivalences of the derived category which respect the component $Stab^\\dagger(X)$ of the stability manifold.

  1. The surface microstructure of cusps and leaflets in rabbit and mouse heart valves

    Directory of Open Access Journals (Sweden)

    Xia Ye

    2014-05-01

    Full Text Available In this investigation, scanning electron microscopy was used to characterize the microstructure on the surfaces of animal heart valve cusps/leaflets. The results showed that though these surfaces appear smooth to the naked eye, they are actually comprised of a double hierarchical structure consisting of a cobblestone-like microstructure and nano-cilia along with mastoids with a directional arrangement. Such nanostructures could play a very important role in the hemocompatibility characteristics of heart valves. On this basis, the model of the microstructure was constructed and theoretical analysis was used to obtain optimal geometric parameters for the rough surface of artificial valve cusps/leaflets. This model may help improve reconstructive techniques and it may be beneficial in the design and fabrication of valve substitutes or partial substitutes. Namely, the model may help ameliorate heart valve replacement surgery.

  2. Numerical method for computing Maass cusp forms on triply punctured two-sphere

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K. T.; Kamari, H. M. [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Zainuddin, H. [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia and Institute for Mathematical Research, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2014-03-05

    A quantum mechanical system on a punctured surface modeled on hyperbolic space has always been an important subject of research in mathematics and physics. This corresponding quantum system is governed by the Schrödinger equation whose solutions are the Maass waveforms. Spectral studies on these Maass waveforms are known to contain both continuous and discrete eigenvalues. The discrete eigenfunctions are usually called the Maass Cusp Forms (MCF) where their discrete eigenvalues are not known analytically. We introduce a numerical method based on Hejhal and Then algorithm using GridMathematica for computing MCF on a punctured surface with three cusps namely the triply punctured two-sphere. We also report on a pullback algorithm for the punctured surface and a point locater algorithm to facilitate the complete pullback which are essential parts of the main algorithm.

  3. Maxillary and Mandibular First Premolars Showing Three-Cusp Pattern: An Unusual Presentation

    Directory of Open Access Journals (Sweden)

    Ramakant Nayak

    2013-01-01

    Full Text Available Dental anatomy is the study of morphology of various teeth in human dentitions. The application of dental anatomy in clinical practice is important, and dentist should have a thorough knowledge regarding the morphology of the teeth. At times as a result of genetic variation, environmental factors, diet of an individual and race, variations in the morphology of the teeth can be observed. These variations have been extensively studied by the researcher in the field of anthropology to define a particular race. The most commonly observed changes include peg-shaped laterals, shovel-shaped incisors, and extra cusp on molar. Common variations documented with regard to maxillary and mandibular first premolars are the variation in the number of roots. But the variations with respect to crown morphology are few. We report a first documented unusual presentation of maxillary and mandibular first premolars with three-cusps pattern in a female patient.

  4. On the ΣN cusp in the pp → pK+Λ reaction

    International Nuclear Information System (INIS)

    Measurements of the pp → pK + Λ reaction at Tp = 2.28 GeV have been carried out at COSY-TOF. In addition to the Λp FSI and N * resonance excitation effects a pronounced narrow structure is observed in the Dalitz plot and in its projection on the p Λ invariant mass. The strongly asymmetric structure appears at the pp → NK + Σ threshold and is interpreted as the ΣN cusp effect. The observed width of about 20 MeV/c 2 is substantially broader than anticipated from previous measurements as well as theoretical predictions. Angular distributions of this cusp structure are shown to be dissimilar to those in the residual pK + Λ channel, but similar to those observed in the pK + Σ 0 channel. (orig.)

  5. Surprises from the resummation of ladders in the ABJ(M) cusp anomalous dimension

    CERN Document Server

    Bonini, Marisa; Preti, Michelangelo; Seminara, Domenico

    2016-01-01

    We study the cusp anomalous dimension in N=6 ABJ(M) theory, identifying a scaling limit in which the ladder diagrams dominate. The resummation is encoded into a Bethe-Salpeter equation that is mapped to a Schroedinger problem, exactly solvable due to the surprising supersymmetry of the effective Hamiltonian. In the ABJ case the solution implies the diagonalization of the U(N) and U(M) building blocks, suggesting the existence of two independent cusp anomalous dimensions and an unexpected exponentiation structure for the related Wilson loops. While consistent with previous perturbative analysis, the strong coupling limit of our result does not agree with the string theory computation, emphasizing a difference with the analogous resummation in the N=4 case.

  6. Scintillation and loss of signal lock from poleward moving auroral forms in the cusp ionosphere

    CERN Document Server

    Oksavik, K; Lorentzen, D A; Baddeley, L J; Moen, J

    2016-01-01

    We present two examples from the cusp ionosphere over Svalbard,where poleward moving auroral forms (PMAFs) are causing significant phase scintillation in signals from navigation satellites. The data were obtained using a combination of ground-based optical instruments and a newly installed multiconstellation navigation signal receiver at Longyearbyen. Both events affected signals from GPS and Global Navigation Satellite System (GLONASS). When one intense PMAF appeared, the signal from one GPS spacecraft also experienced a temporary loss of signal lock. Although several polar cap patches were also observed in the area as enhancements in total electron content, the most severe scintillation and loss of signal lock appear to be attributed to very intense PMAF activity. This shows that PMAFs are locations of strong ionospheric irregularities, which at times may cause more severe disturbances in the cusp ionosphere for navigation signals than polar cap patches.

  7. STATISTICAL MECHANICS OF COLLISIONLESS ORBITS. I. ORIGIN OF CENTRAL CUSPS IN DARK-MATTER HALOS

    International Nuclear Information System (INIS)

    We present an equilibrium statistical mechanical theory of collisionless self-gravitational systems with isotropic velocity distributions. Compared with existing standard theories, we introduce two changes: (1) the number of possible microstates is computed in energy (orbit) space rather than phase space and (2) low occupation numbers are treated more appropriately than they are using Stirling's approximation. Combined, the two modifications predict that the relaxed parts of collisionless self-gravitating systems, such as dark-matter halos, have a differential energy distribution N(ε) ∝ [exp(φ0 - ε)-1], dubbed 'DARKexp'. Such systems have central power-law density cusps ρ(r) ∝ r-1, which suggests a statistical mechanical origin of cusps in simulated dark-matter halos.

  8. An Investigation of the Low-Latitude Boundary Layer at Mid-Altitudes in the Cusp

    Science.gov (United States)

    Chandler, Michael O.; Avanov, Levon A.

    2006-01-01

    We have begun an investigation of the nature of the low-latitude boundary layer in the mid-altitude cusp region using data from the Polar spacecraft. This region has been routinely sampled for about three months each year for the periods 1999-2001 and 2004-2006. The low-to-mid-energy ion instruments frequently observed dense, magnetosheath-like plasma deep (in terms of distance from the magnetopause and in invariant latitude) in the magnetosphere. We seek to understand the morphology of the LLBL as it projects from the sub-solar region into the cusp and determine the influences on this morphology. An initial survey of the data is ongoing and we present here an overview of our intended study and some preliminary results.

  9. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... corner the blood being ejected. And this is something we use to help guide the surgeons in ... now called a mini-thorocotomy or is this something different? This is a partial upper sternotomy is ...

  10. Wave particle interactions in the high-altitude polar cusp: a Cluster case study

    OpenAIRE

    Grison, B.; Sahraoui, F.; B. Lavraud; T. Chust; N. Cornilleau-Wehrlin; Rème, H.; Balogh, A.; André, M.

    2005-01-01

    On 23 March 2002, the four Cluster spacecraft crossed in close configuration (~100 km separation) the high-altitude (10 RE) cusp region. During a large part of the crossing, the STAFF and EFW instruments have detected strong electromagnetic wave activity at low frequencies, especially when intense field-aligned proton fluxes were detected by the CIS/HIA instrument. In all likelihood, such fluxes correspond to newly-reconnected field lines. A focus on ...

  11. Observations of field-aligned currents, particles, and plasma drift in the polar cusps near solstice

    International Nuclear Information System (INIS)

    Observation of particles, magnetic fields, and convective flow in the southern polar region by the AE-C spacecraft in the spinning mode have provided a unique opportunity to study the polar cusp. Magnetic perturbations observed by TRIAD within 2 hours of the AE-C pass provide field-aligned current data from the same local time in the northern hemisphere. The spinning mode of AE-C has enabled the utilization of the Z axis magnetometer for Birkeland current observations in conjunction with particle and drift measurements. This pass, AE-C orbit 16723, occurred on January 15, 1977, at approx.0145 UT, 25 days after solstice. The 3-hour Kp = 4- and the interplanetary magnetic field B/sub y/ was negative during this time. The average B/sub z/ = 1.9 nT and -1.1 nT during the first two hourly intervals on January 15, 1977. At this UT, the geomagnetic axis was at a near maximum inclination of approx.350 with the southern polar cusp directed toward the sun. Measurements from the low energy electron experiment (LEE) revealed intense fluxes of soft (100 eV) 'cusp-like' (Maxwellian) electrons throughout the prenoon polar cap. AE-C magnetometer and drift meter measurements detected three alternately directed current sheets associated with the 'throat' of the ion convection pattern and consistent with gradients in the ion drift velocities. The upward directed current can be identified as the dominant cusp current appropriate for B/sub y/0 lower latitude than those detected by AE-C

  12. Massless radiation from Strings: quantum spectrum average statistics and cusp-kink configurations

    OpenAIRE

    Iengo, Roberto

    2006-01-01

    We derive general formulae for computing the average spectrum for Bosonic or Fermionic massless emission from generic or particular sets of closed superstring quantum states, among the many occurring at a given large value of the number operator. In particular we look for states that can produce a Bosonic spectrum resembling the classical spectrum expected for peculiar cusp-like or kink-like classical configurations, and we perform a statistical counting of their average number. The results c...

  13. Prevalence of talon cusps in a Portuguese population: Forensic identification significance of a rare trait

    OpenAIRE

    Ricardo Jorge Simões; Hugo F.V. Cardoso; Inês Morais Caldas

    2014-01-01

    Background: Dental techniques are frequently used in human identification; some of those include comparative analyses of dental features that, being rare or unique to an individual, can establish a positive identification. The usefulness of each feature depends on its population, frequency, and uniqueness. The aim of this study was to determine the prevalence of talon cusps in a Portuguese population. Materials and Methods: A prospective study was performed. Three hundred and two patients...

  14. Realizing stock market crashes: stochastic cusp catastrophe model of returns under time-varying volatility

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Kukačka, Jiří

    2015-01-01

    Roč. 15, č. 6 (2015), s. 959-973. ISSN 1469-7688 R&D Projects: GA ČR GA402/09/0965; GA ČR GA13-32263S EU Projects: European Commission 612955 - FINMAP Institutional support: RVO:67985556 Keywords : Stochastic cusp catastrophe model * Realized volatility * Bifurcations * Stock market crash Subject RIV: AH - Economics Impact factor: 0.653, year: 2014 http://library.utia.cas.cz/separaty/2014/E/barunik-0434202.pdf

  15. Ionospheric cusp flows pulsed by solar wind Alfvén waves

    OpenAIRE

    Prikryl, P.; Provan, G.; K. A. McWilliams; Yeoman, T. K.

    2002-01-01

    Pulsed ionospheric flows (PIFs) in the cusp foot-print have been observed by the SuperDARN radars with periods between a few minutes and several tens of minutes. PIFs are believed to be a consequence of the interplanetary magnetic field (IMF) reconnection with the magnetospheric magnetic field on the dayside magnetopause, ionospheric signatures of flux transfer events (FTEs). The quasiperiodic PIFs are correlated with Alfvénic fluctuations observed in the upstream solar wind. It is con...

  16. Chorus observations by the Polar spacecraft near the mid-altitude cusp

    Czech Academy of Sciences Publication Activity Database

    Menietti, J. D.; Santolík, Ondřej; Abaci, P. C.

    2009-01-01

    Roč. 57, č. 12 (2009), s. 1412-1418. ISSN 0032-0633 R&D Projects: GA AV ČR IAA301120601 Grant ostatní: NSF(US) ATM-04-43531; NASA(US) NNG05GM52G.; GA MŠk(CZ) ME 842 Institutional research plan: CEZ:AV0Z30420517 Keywords : chorus * mid- altitude cusp * Polar spacecraft Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.067, year: 2009

  17. Sources of the cusp plasma for the different sign of IMF By

    Czech Academy of Sciences Publication Activity Database

    Šimůnek, Jiří; Šafránková, J.; Němeček, Z.; Wing, S.

    Prague: MATFYZPRESS, 2002 - (Šafránková, J.), s. 244-251 ISBN 80-85863-88-X. [Annual Conference of Doctoral Students /11./. Prague (CZ), 11.06.2002-14.06.2002] R&D Projects: GA ČR GA205/02/0947 Institutional research plan: CEZ:AV0Z3042911 Keywords : cusp plasma * magnetopause * INTERBALL-1 Subject RIV: BL - Plasma and Gas Discharge Physics

  18. Two Azimuthally Separated Regions of Cusp Ion Injection Observed via Energetic Neutral Atoms

    Science.gov (United States)

    Abe, M.; Taguchi, S.; Collier, M. R.; Moore, T. E.

    2011-01-01

    The low-energy neutral atom (LENA) imager on the IMAGE spacecraft can detect energetic neutral atoms produced by ion injection into the cusp through a charge exchange with the Earth's hydrogen exosphere. We examined the occurrence of the LENA cusp signal during positive IMF B(sub z) in terms of the arrival direction and the IMF clock angle theta(sub CA). Results of statistical analyses show that the occurrence frequency is high on the postnoon side when theta(sub CA) is between approximately 20 degrees and approximately 50 degrees. This is ascribed to ion injection caused by cusp reconnection typical of positive IMF B(sub z). Our results also show that there is another situation of high occurrence frequency, which can be identified with theta(sub CA) of approximately 30 degrees to approximately 80 degrees. When theta(sub CA) is relatively large (60 degrees - 80 degrees), occurrence frequencies are high at relatively low latitudes over a wide extent spanning both prenoon and postnoon sectors. This feature suggests that the ion injection is caused by reconnection at the dayside magnetopause. Its postnoon side boundary shifts toward the prenoon as theta(sub CA) decreases. When theta(sub CA) is less than approximately 50 degrees, the high occurrence frequency exists well inside the prenoon sector, which is azimuthally separated from the postnoon region ascribed to cusp reconnection. The prenoon region, which is thought due to ion injection caused by dayside reconnection, may explain the recent report that proton aurora brightening occurs in the unanticipated prenoon sector of the northern high-latitude ionosphere for IMF B(sub y) greater than 0 and B(sub z) greater than 0.

  19. Cusp catastrophe of symmetry breaking in two-component Bose-Einstein condensates

    International Nuclear Information System (INIS)

    Bifurcation analysis is applied to the spontaneous spatial symmetry breaking occurring in the ground state of two-component Bose-Einstein condensates. The cusp catastrophe describing the supercritical pitchfork bifurcation associated with the symmetry breaking is derived via the identification of the local curvature of the Gross-Pitaevskii energy functional. The bifurcation diagram and universal scaling laws for the eigenvalue and energy are obtained from the catastrophe function

  20. Spatial structures of magnetic depression in the Earth's high-altitude cusp: Cluster multipoint observations

    Czech Academy of Sciences Publication Activity Database

    Shi, Q. Q.; Pu, Z. Y.; Souček, Jan; Zong, Q. -G.; Fu, S. Y.; Xie, L.; Chen, Y.; Zhang, H.; Li, L.; Xia, L. D.; Liu, Z. X.; Lucek, E.; Fazakerley, A. N.; Reme, H.

    2009-01-01

    Roč. 114, - (2009), A10202/1-A10202/13. ISSN 0148-0227 R&D Projects: GA AV ČR IAA301120601 Institutional research plan: CEZ:AV0Z30420517 Keywords : high-altitude cusp * mirror modes * magnetic holes * multi-spacecraft methods Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.082, year: 2009

  1. Turner's syndrome associated with bicuspid aortic stenosis and dissecting aortic aneurysm

    OpenAIRE

    Slater, D N; Grundman, M. J.; Mitchell, L

    1982-01-01

    A case of Turner's syndrome is described associated with bicuspid aortic stenosis and fatal rupture of a thoracic dissecting aortic aneurysm. Histology of the aneurysm showed severe cystic medial necrosis. This association has not been previously described in the absence of coarctation.

  2. Combined surgical and catheter-based treatment of extensive thoracic aortic aneurysm and aortic valve stenosis

    DEFF Research Database (Denmark)

    De Backer, Ole; Lönn, Lars; Søndergaard, Lars

    2015-01-01

    An extensive thoracic aortic aneurysm (TAA) is a potentially life-threatening condition and remains a technical challenge to surgeons. Over the past decade, repair of aortic arch aneurysms has been accomplished using both hybrid (open and endovascular) and totally endovascular techniques. Thoraci...

  3. Weak annihilation cusp inside the dark matter spike about a black hole

    CERN Document Server

    Shapiro, Stuart L

    2016-01-01

    We reinvestigate the effect of annihilations on the distribution of collisionless dark matter (DM) in a spherical density spike around a massive black hole. We first construct a very simple, pedagogic, analytic model for an isotropic phase space distribution function that accounts for annihilation and reproduces the "weak cusp" found by Vasiliev for DM deep within the spike and away from its boundaries. The DM density in the cusp varies as $r^{-1/2}$ for $s$-wave annihilation, where $r$ is the distance from the central black hole, and is not a flat "plateau" profile. We then extend this model by incorporating a loss cone that accounts for the capture of DM particles by the hole. The loss cone is implemented by a boundary condition that removes capture orbits, resulting in an anisotropic distribution function. Finally, we evolve an initial spike distribution function by integrating the Boltzmann equation to show how the weak cusp grows and its density decreases with time. We treat two cases, one for $s$-wave a...

  4. Four point measurements of electrons using PEACE in the high-altitude cusp

    Directory of Open Access Journals (Sweden)

    M. G. G. T. Taylor

    Full Text Available We present examples of electron measurements from the PEACE instruments on the Cluster spacecraft in the high-latitude, high-altitude region of the Earth’s magnetosphere. Using electron density and energy spectra measurements, we examine two cases where the orbit of the Cluster tetrahedron is outbound over the northern hemisphere, in the afternoon sector approaching the magnetopause. Data from the magnetometer is also used to pinpoint the position of the spacecraft with respect to magnetospheric boundaries. This preliminary work specifically highlights the benefit of the multipoint measurement capability of the Cluster mission. In the first case, we observe a small-scale spatial structure within the magnetopause boundary layer. The Cluster spacecraft initially straddle a boundary, characterised by a discontinuous change in the plasma population, with a pair of spacecraft on either side. This is followed by a complete crossing of the boundary by all four spacecraft. In the second case, Cluster encounters an isolated region of higher energy electrons within the cusp. The characteristics of this region are consistent with a trapped boundary layer plasma sheet population on closed magnetospheric field lines. However, a boundary motion study indicates that this region convects past Cluster, a characteristic more consistent with open field lines. An interpretation of this event in terms of the motion of the cusp boundary region is presented.

    Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; solar wind-magnetosphere interactions

  5. Observations of field-aligned currents, particles, and plasma drift in the polar cusps near solstice

    Science.gov (United States)

    Bythrow, P. F.; Potemra, T. A.; Hoffman, R. A.

    1982-01-01

    Magnetic perturbations observed by the TRIAD magnetometer within two hours of an AE-C spacecraft pass provide field-aligned current data, from the same local time in the northern hemisphere, for a study of the polar cusp. The AE-C spinning mode has allowed the use of the Z-axis magnetometer for Birkeland current observations, in conjunction with particle and drift measurements. The average B(z) were found to be 1.9 nT and -1.1 nT during the first two hourly intervals on January 15, 1977. Measurements from the low energy electron experiment revealed intense fluxes of soft, cusp-like 100 eV Maxwellian electrons throughout the prenoon polar cap. The upward directed current can be identified as the dominant cusp current appropriate for B(y) values lower than zero, while the downward directed current, which has the appropriate sign of a dayside region 1 current, is observed to lie entirely within a westerly, antisunward-convecting plasma.

  6. The magnetic configuration of the high-latitude cusp and dayside magnetopause under strong magnetic shears

    Science.gov (United States)

    Shen, C.; Dunlop, M.; Ma, Y. H.; Chen, Z. Q.; Yan, G. Q.; Liu, Z. X.; Bogdanova, Y. V.; Sibeck, D. G.; Carr, C. M.; Zhang, Q. H.; Lucek, E.

    2011-09-01

    This paper investigates the structure of the magnetic field near the magnetopause (MP) by analyzing the multiple-point magnetic measurements from the Cluster mission. In this paper, the spatial distribution of the curvature radius of the MP surface at the noon-midnight meridian and for situations with moderate dynamical pressure of solar wind is implied from direct measurements of magnetic field curvature for the first time. The investigation focused on conditions of strong magnetic shear and in which a clear boundary layer is present at the MP. It has been confirmed that the magnetic field lines surrounding the cusp bend sunward at the precusp region and tailward at the postcusp region, implying the existence of a cusp field indentation. The minimum curvature radius of the near-MP field at both precusp and postcusp regions is about 2 RE. As the latitude decreases, the curvature radius at the MP increases gradually, so that, as the subsolar point is approached, the curvature radius of the MP is nearly equal to the geocentric distance. These results compare well with existing MP models but reveal the limitations inherent in such statistical estimates of local MP curvature, particularly surrounding the cusp regions. The analysis of the magnetic measurements has also verified the existence of the magnetic bottles at both precusp and postcusp regions, which may play a role for the trapping of the charged particles of magnetosphere.

  7. The relation between the spherical aberration of a lens and the spun cusp diffraction catastrophe

    Science.gov (United States)

    Nye, J. F.

    2005-01-01

    A lens with spherical aberration, illuminated with an axial plane wave, produces a rotationally-symmetric cusped caustic together with an axial caustic line. Both caustics are truncated by the finite aperture of the lens, and they are decorated by diffraction. One may pass continuously from the limit of small aperture, where the diffraction pattern consists simply of Airy rings around the focus, to the limit of infinite aperture, where the diffraction pattern is that of the three-dimensional spun cusp. This contains ring zeros both inside and outside the cusped caustic. The rings are structurally stable phase singularities (wave dislocations), whose progress out of the focal plane can be traced as the aperture is enlarged. In any axial plane the dislocations are points. Before reaching their final destinations these dislocation points invariably trace out spirals, whose detailed form may be deduced by a perturbation theory. Apart from this, their trajectories, births and deaths are different from those encountered in the analogous case of the two-dimensional Pearcey pattern.

  8. Role of magnetic cusp for multiple axial potential structures (MAPS) formation

    International Nuclear Information System (INIS)

    Cusp like magnetic field profile in expanding helicon experimental system is studied for the formation of multiple axial potential structures (MAPS). Double layer like this potential structures formation in this kind of expanding helicon system produces thrusts along the axial direction. Observation of multiple ion beams is an indirect evidence for the formation of multiple double layers like potential structures. However, there is no such direct evidence available to identify the strength and location for the formation of these structures, in magnetic and geometric expanding helicon plasma systems. Transition from single to multiple axial potential structures is observed by varying the magnetic field topology from diverging to cusp. A localized threshold density is required to maintain the steady state potential structure inside the bulk plasma. Cusp like magnetic field profile inside the expansion controls this downstream density rise and beyond the threshold limit of this density rise, the second potential structure is formed. In this presentation, quantitative discussion will be presented to understand the root causes to maintain the critical density for the formation of MAPS and the mechanism responsible for maintaining this density inhomogeneity in these expanding plasmas. (author)

  9. Computation of the Knife-Edge Cusp of a Rising Bubble in a Viscoelastic Fluid

    Science.gov (United States)

    You, Ruobo; Haj-Hariri, Hossein

    2006-11-01

    We consider the buoyant rise of an originally-spherical bubble through a viscoelastic fluid. Experiments have demonstrated that the sharp trailing edge could develop a three dimensional cusp of ``knife-like'' shape under certain conditions (high capillary number, large drop size). In order to understand the complex physics of this phenomenon, we have conducted a linear, three-dimensional temporal stability analysis of a computationally-obtained axisymmetric cusped bubble. The in-house time-accurate code is control-volume based and uses a body-fitted grid. Flux-difference splitting is employed to handle large Deborah numbers. Artificial compressibility is used for time marching. The resulting eigenanalysis shows the only linearly-unstable mode to be the one with azimuthal wavenumber of 2. The eigenvalue is real and the nature of instability is an exchange of stability. Thus an axisymmetric cusp can indeed develop into a knife-like shape. An investigation of the energy production and dissipation for the disturbances shows that the normal pressure gradient of the base-state along the free surface plays an important role in the evolution of the instability.

  10. In Vitro Repair of Fractured Fiber-Reinforced Cusp-Replacing Composite Restorations

    Directory of Open Access Journals (Sweden)

    Willem M. M. Fennis

    2011-01-01

    Full Text Available Objective. To assess fracture resistance and failure mode of repaired fiber-reinforced composite (FRC cusp-replacing restorations. Methods. Sixteen extracted human premolars with fractured cusp-replacing woven (Group (A or unidirectional (Group (B FRC restorations from a previous loading experiment were repaired with resin composite and loaded to fracture. Results. Differences in fracture loads between groups were not statistically significant (P=0.34. Fracture loads of repaired specimens were significantly lower than those of original specimens (P=0.02 for Group (A and P<0.001 for Group (B. Majority of specimens showed failure along the repaired surface. In Group (B 89% of specimens showed intact tooth substrate after restoration fracture, while this was 28% in Group (A (P=0.04. Conclusion. Fractured cusp-replacing FRC restorations that are repaired with resin composite show about half of fracture resistance of original restorations. Mode of failure with a base of unidirectional fibers is predominantly adhesive.

  11. ALTERNATIVE METHOD OF SURGICAL CORRECTION OF DISSECTING AORTIC ANEURYSMS WITH AORTIC INSUFFIECIENCY

    Directory of Open Access Journals (Sweden)

    M. L. Semenovsky

    2009-01-01

    Full Text Available Patients with dissecting aortic aneurysm and associated acute aortic insufficiency form a group of seriously ill patients with significant cardiac failure, generally involving other organs and systems. It justifies an attempt to reduce a surgical risk, by using more sparing procedures, including supracoronary replacement of the ascending aorta with its root reconstruction. The latter has been performed in 27 patients (mean 54,5 ± 2,1 years with dissecting aortic aneurysm and aortic valvular insufficiency in 1996 to 2009. The major etiological factor was atherosclerosis (88%/ Seventeen (63%, 6 (22,2% and 4 (16% had types I, IIA and II dissection, respectively. Overall hospital mortality was 11%. In late period, progressive aneurysm dissection needed reinterventions in 2 cases. The competence of the reconstructed aortic valve was satisfactory both just after surgery and throughout the follow-up. Indications for this option of chronic correction, surgical techniques, and immediate and long-term results are outlined. 

  12. New frontiers in aortic therapy: focus on current trials and devices in transcatheter aortic valve replacement.

    Science.gov (United States)

    Gutsche, Jacob T; Patel, Prakash A; Walsh, Elizabeth K; Sophocles, Aris; Chern, Sy-Yeu S; Jones, David B; Anwaruddin, Saif; Desai, Nimesh D; Weiss, Stuart J; Augoustides, John G T

    2015-04-01

    The first decade of clinical experience with transcatheter aortic valve replacement since 2002 saw the development of 2 main valve systems, namely the Edwards Sapien balloon-expandable valve series and the Medtronic self-expanding CoreValve. These 2 valve platforms now have achieved commercial approval and application worldwide in patients with severe aortic stenosis whose perioperative risk for surgical intervention is high or extreme. In the second decade of transcatheter aortic valve replacement, clinical experience and refinements in valve design have resulted in clinical drift towards lower patient risk cohorts. There are currently 2 major trials, PARTNER II and SURTAVI, that are both evaluating the role of transcatheter aortic valve replacement in intermediate-risk patient cohorts. The results from these landmark trials may usher in a new clinical paradigm for transcatheter aortic valve replacement in its second decade. PMID:25572322

  13. Abdominal Aortic Diameter Is Increased in Males with a Family History of Abdominal Aortic Aneurysms

    DEFF Research Database (Denmark)

    Mejnert Jørgensen, Trine; Houlind, K; Green, A;

    2014-01-01

    participants with male and female relatives with AAA. DESIGN: Observational population-based cross-sectional study. MATERIALS: 18,614 male participants screened for AAA in the VIVA-trial 2008-2011 with information on both family history of AAA and maximal aortic diameter. METHODS: Standardized ultrasound scan......OBJECTIVE: To investigate, at a population level, whether a family history of abdominal aortic aneurysm (AAA) is independently related to increased aortic diameter and prevalence of AAA in men, and to elucidate whether the mean aortic diameter and the prevalence of AAA are different between...... measurement of maximum antero-posterior aortic diameter. Family history obtained by questionnaire. Multivariate regression analysis was used to test for confounders: age, sex, smoking, comorbidity and medication. RESULTS: From the screened cohort, 569 participants had at least one first degree relative...

  14. Vasopressor mechanisms in acute aortic coarctation hypertension

    Directory of Open Access Journals (Sweden)

    Salgado H.C.

    1997-01-01

    Full Text Available Angiotensin II (ANG II and vasopressin (AVP act together with the mechanical effect of aortic constriction in the onset of acute aortic coarctation hypertension. Blockade of ANG II and AVP V1 receptors demonstrated that ANG II acts on the prompt (5 min rise in pressure whereas AVP is responsible for the maintenance (30-45 min of the arterial pressure elevation during aortic coarctation. Hormone assays carried out on blood collected from conscious rats submitted to aortic constriction supported a role for ANG II in the early stage and a combined role for both ANG II and AVP in the maintenance of proximal hypertension. As expected, a role for catecholamines was ruled out in this model of hypertension, presumably due to the inhibitory effect of the sinoaortic baroreceptors. The lack of afferent feedback from the kidneys for AVP release from the central nervous system in rats with previous renal denervation allowed ANG II to play the major role in the onset of the hypertensive response. Median eminence-lesioned rats exhibited a prompt increase in proximal pressure followed by a progressive decline to lower hypertensive levels, revealing a significant role for the integrity of the neuroaxis in the maintenance of the aortic coarctation hypertension through the release of AVP. In conclusion, the important issue raised by this model of hypertension is the likelihood of a link between some vascular territory - probably renal - below the coarctation triggering the release of AVP, with this vasoconstrictor hormone participating with Ang II and the mechanical effect of aortic constriction in the acute aortic coarctation hypertension

  15. Dynamic damping of the aortic pressure trace during hyperemia: the impact on fractional flow reserve measurement.

    Science.gov (United States)

    Lockie, Tim; Rolandi, M Cristina; Piek, Jan J

    2013-10-01

    We report on two cases that illustrate an important caveat in the measurement of fractional flow reserve (FFR) in coronary arteries. To obtain accurate FFR measurements, two fundamental requirements must be fulfilled. One is to minimize microvascular resistance; the other is that there is no damping of the proximal aortic pressure trace. A problem with either of these requirements can be a source of serious error in the measurement of FFR. In each case we present here, despite a good aortic pressure trace at the start of the procedure, there is dynamic damping of the pressure trace during hyperemia, secondary to axial migration of the guiding catheter into the left main stem (LMS). In both cases, a normal aortic pressure trace (Pa) is present at baseline. After intracoronary adenosine injection, there was a fall in both mean Pa and distal coronary pressure (Pd) concomitant with damping of Pa, evidenced by loss of the dicrotic notch and ventricularization of the pressure trace. The resultant FFR value is underestimated. As hyperemia wears off, both pressure traces return to normal with good articulation of the dicrotic notch. When the procedure was repeated taking care to ensure that the guide did not move into the LMS during hyperemia, the Pa trace remained stable following intracoronary adenosine, while mean Pd decreased as before. In both cases, hemodynamically significant lesions were demonstrated that had been masked by the artifactual drop in Pa during the first attempt. PMID:24088431

  16. Transition to palliative care when transcatheter aortic valve implantation is not an option: opportunities and recommendations

    Science.gov (United States)

    Lauck, Sandra B.; Gibson, Jennifer A.; Baumbusch, Jennifer; Carroll, Sandra L.; Achtem, Leslie; Kimel, Gil; Nordquist, Cindy; Cheung, Anson; Boone, Robert H.; Ye, Jian; Wood, David A.; Webb, John G.

    2016-01-01

    Purpose of review Transcatheter aortic valve implantation (TAVI) is the recommended treatment for most patients with symptomatic aortic stenosis at high surgical risk. However, TAVI may be clinically futile for patients who have multiple comorbidities and excessive frailty. This group benefits from transition to palliative care to maximize quality of life, improve symptoms, and ensure continuity of health services. We discuss the clinical determination of utility and futility, explore the current evidence guiding the integration of palliative care in procedure-focused cardiac programs, and outline recommendations for TAVI programs. Recent findings The determination of futility of treatment in elderly patients with aortic stenosis is challenging. There is a paucity of research available to guide best practices when TAVI is not an option. Opportunities exist to build on the evidence gained in the management of end of life and heart failure. TAVI programs and primary care providers can facilitate improved communication and processes of care to provide decision support and transition to palliative care. Summary The increased availability of transcatheter options for the management of valvular heart disease will increase the assessment of people with life-limiting conditions for whom treatment may not be an option. It is pivotal to bridge cardiac innovation and palliation to optimize patient outcomes. PMID:26716394

  17. A Clinicopathological Study on Aortic Valves in Children

    Institute of Scientific and Technical Information of China (English)

    HUANG Ping; WANG Hongwei; ZHANG Zhenlu; HU Xiufen; LI Yanping; CHENG Peixuan; LIU Jianying

    2007-01-01

    In order to investigate the clinicopathological characteristics of aortic valve disease in children, all the native surgically excised aortic valves obtained between January 2003 and December 2005 were studied macroscopically and microscopically. The patients' medical records were reviewed and the clinical information was extracted. According to preoperative echocardiography, intraoperative assessment, and postoperative pathology, combined with clinical symptoms and signs, aortic valve diseases were divided into three categories: aortic stenosis (AS), aortic insufficiency (AI), and aortic stenosis with insufficiency (AS-AI). The etiology was determined according to the macroscopic, microscopic and clinical findings. The results showed that among 70 aortic valves, patient age ranged from 6 to 18 years, with a mean of 15.4 years, and there were 56 boys and 14 girts (male: female=4:1). Forty-four children only had pure aortic valve disease, and the other 26 children had aortic valve disease associated with other heart valve diseases. There were 5 cases of AS (7.14%), 60 cases of AI (85.71%) and 5 cases of AS-AI (7.14%). The causes were congenital aortic valve malformation (32 cases, 45.71%), rheumatic disease (28 cases, 40%), infective endocarditis (7 cases,10%), Marfan syndrome (2 cases, 2.86%), and undetermined (1 case, 1.43%). It was concluded that the common causes of aortic valve disease in order of frequency in children were congenital aortic valve malformation, rheumatic disease, infective endocarditis, and Marfan syndrome. AI was more common in children with aortic valve disease. Compared with adult patients, congenital bicuspid aortic valve in children was often AI. Histologically, the leaflets of congenital bicuspid aortic valve were mainly myxomatous, fibrosis and calcification less seen. AI was frequently found in rheumatic disease, mostly associated with other heart valve diseases. Macroscopic and microscopic examinations together with clinical

  18. The German Aortic Valve Registry (GARY): in-hospital outcome

    OpenAIRE

    Hamm, Christian W.; Möllmann, Helge; Holzhey, David; Beckmann, Andreas; Veit, Christof; Figulla, Hans-Reiner; Cremer, J; Kuck, Karl-Heinz; Lange, Rüdiger; Zahn, Ralf; Sack, Stefan; Schuler, Gerhard; Walther, Thomas; Beyersdorf, Friedhelm; Böhm, Michael

    2013-01-01

    Background Aortic stenosis is a frequent valvular disease especially in elderly patients. Catheter-based valve implantation has emerged as a valuable treatment approach for these patients being either at very high risk for conventional surgery or even deemed inoperable. The German Aortic Valve Registry (GARY) provides data on conventional and catheter-based aortic procedures on an all-comers basis. Methods and results A total of 13 860 consecutive patients undergoing repair for aortic valve d...

  19. Rapid prototyping in aortic surgery.

    Science.gov (United States)

    Bangeas, Petros; Voulalas, Grigorios; Ktenidis, Kiriakos

    2016-04-01

    3D printing provides the sequential addition of material layers and, thus, the opportunity to print parts and components made of different materials with variable mechanical and physical properties. It helps us create 3D anatomical models for the better planning of surgical procedures when needed, since it can reveal any complex anatomical feature. Images of abdominal aortic aneurysms received by computed tomographic angiography were converted into 3D images using a Google SketchUp free software and saved in stereolithography format. Using a 3D printer (Makerbot), a model made of polylactic acid material (thermoplastic filament) was printed. A 3D model of an abdominal aorta aneurysm was created in 138 min, while the model was a precise copy of the aorta visualized in the computed tomographic images. The total cost (including the initial cost of the printer) reached 1303.00 euros. 3D imaging and modelling using different materials can be very useful in cases when anatomical difficulties are recognized through the computed tomographic images and a tactile approach is demanded preoperatively. In this way, major complications during abdominal aorta aneurysm management can be predicted and prevented. Furthermore, the model can be used as a mould; the development of new, more biocompatible, less antigenic and individualized can become a challenge in the future. PMID:26803324

  20. Balloon aortic valvuloplasty in pregnancy with severe aortic stenosis and infective endocarditis

    Directory of Open Access Journals (Sweden)

    Vinotha

    2012-12-01

    Full Text Available Twenty seven year old lady, previously diagnosed to have aortic stenosis, presented to the obstetric outpatient department at 19 weeks of gestation with fever and breathlessness, NYHA class 4, for one week. Two D Echo revealed left ventricular hypertrophy, a severely stenosed, calcified bicuspid aortic valve, with vegetations on aortic and mitral valves and severe mitral regurgitation. Blood cultures grew nutrionally variant streptococci and she was treated with crystalline penicillin and gentamicin. She stabilised clinically by 21 weeks, by which time, the risk of termination of pregnancy was comparable to continuing the pregnancy. She underwent balloon aortic valvuloplasty. Post balloon aortic valvuloplasty, she was stable. At 34+2 weeks, she underwent emergency LSCS, the indication being intrauterine growth restriction with fetal compromise and breech presentation. She delivered a baby girl, 1.6 kg, Apgar 9 & 10. Our case report highlights the fact that a timely, balloon aortic valvuloplasty can be life saving for patients with pregnancy complicated by severe aortic stenosis and infective endocarditis. [Int J Reprod Contracept Obstet Gynecol 2012; 1(1.000: 69-71

  1. Endoluminal stent-graft management for type B aortic dissection and descending thoracic aortic aneurysm

    International Nuclear Information System (INIS)

    Objective: To evaluate the feasibility and short-term early results of endoluminal stent-graft placement in the Stanford B type aortic dissection and the descending thoracic aortic aneurysms. Methods: From March 2003 to September 2005, a total of 31 patients underwent placement of endovascular stent-grafts ,including the descending thoracic aortic aneurysm (n=2) and Standford B type aortic dissection (n=29). All patients had hypertension, with urgent onset of progressive thoracic pain in 27. Two kinds of stent-graft were used in this series: the Talent (Medtronic) in 15 and Aegis (Microportmedicine, Shanghai) in 16 patients. Follow-up was carried out with clinical observations and CTA. Results: Stent-graft implantation for the proximal entry closure was successfully performed in all patients. The DSA of immediately post deployment of the stent-graft showed complete occlusion the proximal entry tear in 23/29 patients with dissection, and complete isolation of the aneurysm in two patients with aortic aneurysm. Endoleak was revealed in 6 patients with dissection. No major complications related to the procedure were encountered. Conclusions: The interventional placement of stent-graft for Type B aortic dissection and descending thoracic aortic aneurysm is safe with satisfactory short-term outcomes. Nonetheless, longer follow-up is highly desirable to assess its real advantages. (authors)

  2. Bicuspid aortic valve and severe aortic stenosis in a newborn exposed to carbamazapine during pregnancy.

    Science.gov (United States)

    Karataş, Zehra; Karataş, Ahmet; Özlü, Tülay; Goksugur, Sevil B; Varan, Birgül

    2014-01-01

    The use of antiepileptic drugs increases the risk of major congenital malformations during pregnancy. Here, we report an infant who had a history of in-utero carbamazepine exposure and who was born with a cardiac malformation. The infant was born at 39 weeks of gestation vaginally to an epileptic mother who had been treated with carbamazepine throughout her pregnancy. He was referred due to cardiac murmur in the second week of his life. The mother had not received folic acid supplementation. Transthoracic echocardiography revealed bicuspid aortic valve, mild aortic stenosis, patent ductus arteriosus, patent foramen ovale and the renal ultrasound revealed mild left hydronephrosis. Follow-up echocardiography performed 14 weeks later showed increased severity of aortic stenosis and percutaneous balloon aortic valvuloplasty was performed. To our knowledge, there is only one case report in the literature mentioning the association of a bicuspid aortic valve and aortic stenosis with oxcarbazepine exposure, which is a structural derivative of carbamazepine. However, there are no reports for association with carbamazepine itself. Bicuspid aorta and aortic stenosis may be among the cardiac malformations that result from the teratogenic effect of carbamazepine. PMID:25584038

  3. Study of Coronary Artery Disease in Single Aortic Valvular Disease

    Institute of Scientific and Technical Information of China (English)

    张斌; 杨伟民; 占亚平

    2003-01-01

    Objectives To analyze the results of coronary angiographies (GAG) in patients with single aortic valvular heart disease; To study the relationship between aortic valve diseases and coronary artery disease (CAD). Methods 105 patients with single aortic valvular heart disease before surgery underwent angiography. The data of clinical characteristics and angiographies were analyzed. Results 51 patients had symptoms of angina pectoris among 105 patients with single aortic valvular heart disease. Seven of them were confirmed coronary artery disease by angiographies. Although the incidence of angina in aortic valve stenosis group was significantly higher than that in aortic valve regurgitation, the probability of combination of CAD in aortic valve stenosis group was similar to the later. However, the probability of combination of CAD in degenerative aortic valve group was significantly higher than the groups of rheumatic, congenitally bicuspid aortic valves, and other causes (p <0.01).Conclusions Angina pectoris is not sensitive for diagnosis of CAD in single aortic valve heart disease.The probability of combination of CAD in degenerative aortic valve disease is higher than that in aortic valve disease with other causes. Coronary angiography is strongly suggested for these patients.

  4. Robotic-assisted aortic valve bypass (apicoaortic conduit) for aortic stenosis.

    Science.gov (United States)

    Gammie, James S; Lehr, Eric J; Griffith, Bartley P; Dawood, Murtaza Y; Bonatti, Johannes

    2011-08-01

    Aortic valve bypass (AVB [apicoaortic conduit]) surgery consists of the construction of a valved conduit between the left ventricular apex and the descending thoracic aorta. In our institution, AVB is routinely performed without cardiopulmonary bypass or manipulation of the ascending aorta or native aortic valve. We report the case of an 83-year-old man with severe symptomatic bioprosthetic aortic stenosis, chronic thrombocytopenia, and a patent bypass graft who underwent robotically assisted beating-heart AVB through an anterior minithoracotomy. The distal anastomosis was constructed entirely using robotic telemanipulation. Robotic assistance enables the performance of beating-heart AVB through a small incision. PMID:21801931

  5. Digital substraction angiography in aortic dissection

    International Nuclear Information System (INIS)

    Regardless of the technical progress in new noninvasive methods, aortography is still regarded as a method providing the necessary information for cases of aortic dissection, especially those requiring emergency operative management. Twenty-four DS-aortographies of patients suspected for aortic dissection are reviewed. Intraarterial DSA is less hazardous owing to the reduced flow rate and quantity of contrast medium required. The relative share of inadequate images is rather high, and conventional cineaortography cannot be invariably replaced by the digital subtracted one. However, angiographic examination in cases suspected for aortic dissection may start with intraarterial digital substraction, and provided the latter proves inconclusive, conventional cineaortography may be resorted to. 6 refs., 3 figs. (orig.)

  6. Acute Aortic Dissection Extending Into the Lung.

    Science.gov (United States)

    Makdisi, George; Said, Sameh M; Schaff, Hartzell V

    2015-07-01

    The radiologic manifestations of ruptured acute aortic dissection, Stanford type A aortic dissection, DeBakey type 1 can present in different radiographic scenarios with devastating outcomes. Here, we present a rare case of a 70-year-old man who presented to the emergency department with chest pain radiating to the back. A chest computed tomography scan showed a Stanford type A, DeBakey type 1, acute aortic dissection ruptured into the aortopulmonary window and stenosing the pulmonary trunk, both main pulmonary arteries, and dissecting the bronchovascular sheaths and flow into the pulmonary interstitium, causing pulmonary interstitial hemorrhage. The patient underwent emergent ascending aorta replacement with hemiarch replacement with circulatory arrest. The postoperative course was unremarkable. PMID:26140779

  7. Transcatheter CoreValve valve-in-valve implantation in a stentless porcine aortic valve for severe aortic regurgitation

    OpenAIRE

    Yong, Celina M; Buchbinder, Maurice; Giacomini, John C

    2014-01-01

    Key Clinical Message We describe the first valve-in-valve Corevalve transcatheter aortic valve replacement in the St. Jude Toronto stentless porcine aortic valve in the United States, which enabled this 59-year-old patient with a history of bacterial endocarditis and aortic regurgitation to avoid heart transplant with complete resolution of his severe left ventricular dysfunction.

  8. Cirurgia das dissecções crónicas da aorta ascendente com insuficiência valvar Surgery of chronic aortic dissection with aortic insufficiency

    Directory of Open Access Journals (Sweden)

    Paulo M Pêgo-Fernandes

    1990-12-01

    menor índice de complicações a médio prazo do que a substituição valvar; 2 a identificação do mecanismno da insuficiência valvar é fundamental para decisão da tática operatória; 3 o uso da cola biológica facilita o manuseio da aorta e pode diminuir o sangramento intra-operatório; 4 quando é necessária a substituição valvar tem-se preferido empregar prótese mecânica dada a maior dificuldade técnica na reoperaçáo nesses pacientes; 5 a aortoplastia não deve ser utilizada devido à alta incidência de redissecção aórtica.In the period of January 1980 to December 1988, 44 patients with chronic aortic dissections and aortic insufficiency were operated on. This group of patients was analized in order to evaluate the evolution of those in which the aortic valve was preserved compared to the group of patients submitted to valvular replacement. The overall preoperative characteristics of these two groups were similar. Valvular replacement was the elected procedure in cases of valvular degeneration or of aortic annular ectasia. In cases of cusp prolapse with enlarged annulus a plastic procedure was used; in 48% of the cases it was possible to preserve the valve. In the 23 patients submitted to valve replacement, the Bentall and De Bono technique was utilized. In six patientes other surgical procedures were associated. Biological adhesives were utilized in every patient operated on from 1986 on. In 41 patients (93% the proximal aorta was substituted and in the remaining three an aortoplasty was performed. Five patients (11% had hospitalar deaths, three due to low-output syndrome, one due to bleeding and one on account of neurological complications. Late death occurred in two patients (4%. The follow-up of the 37 surviving patients varied from two to 108 months (mean: 18 months; of these, 78% were in fuctional class I, and the others in class II. Two patients that had their aortic valve preserved presented mild aortic insufficiency. Three patients with

  9. Diagnostic imaging of acute aortic dissection

    International Nuclear Information System (INIS)

    One hundred and nineteen patients with aortic dissection who underwent diagnostic imaging were reviewed and angiographic findings as well as those of CT were analysed. Thirty eight cases (43.1%) had non-contrast opacified false lumen, the type of which we call 'thrombosed type aortic dissection'. A comparative study of the thrombosed type with the patent type of false lumens was made particularly from the stand point of the characteristic diagnostic imagings (CT and angiography). At the same time, the pitfalls of these imagings in thrombosed type aortic dissection were studied. At the onset the average age of thrombosed type was 62.3 years old, while that of the patent type was 57.3. A statistical significance between the two groups was p<0.05. Thrombosed type in all cases was caused by atherosclerosis, whereas patent type was caused by the Marfan's syndrome in 11 cases. Other clinical findings, such as initial symptoms and blood pressure revealed no significant differences between the two groups. Pre-contrast CT in acute thrombosed type aortic dissection showed 'hyperdense crescent sign' in 89.4%. However, in 3 cases with thrombosed type in which the pre-contrast CT showed 'hyperdense crescent sign' contrast-enhanced CT detected no clear evidence of aortic dissection in the same site. This was due to obscurity induced by contrast medium. Angiographic findings of thrombosed type were classified into 3 groups: normal type, stenosed true lumen type and ulcer-like projection type. The incidence of normal type was estimated to be 48.4%, whereas stenosed true lumen type was 24.2% and ulcer-like projection was 27.7%. The present study concluded that thrombosed type is not rare in acute aortic dissection and contrast-enhanced CT as well as pre-contrast CT, is of great value in diagnosing thrombosed type. 'Hyperdense crescent sign' in pre-contrast CT is characteristic of intramural hematoma. (author)

  10. Anesthesia Approach in Endovascular Aortic Reconstruction

    Directory of Open Access Journals (Sweden)

    Ayşin Alagöl

    2013-03-01

    Full Text Available Introduction: We have analyzed our initial results of our anesthesia techniques in our new-onset endovascular aortic reconstruction cases.Patients and Methods: The perioperative data of 15 elective and emergent endovascular aortic reconstruction cases that were operated in 2010-2011 were collected in a database. The choice of anesthesia was made by the risk factors, surgical team’s preferences, type and location of the aortic pathology and by the predicted operation duration. The data of local and general anesthesia cases were compared.Results: Thirteen (86.7% cases were male and 2 (13.3% female. Eleven patients were in ASA Class III. The demographic parameters, ASA classifications, concurrent diseases were similar in both groups. Thirteen (86.7% cases had infrarenal abdominal aortic aneurysm and 2 (13.3% had Type III aortic dissection. The diastolic arterial pressures were lower in general anesthesia group in 20th and 40th minutes’ measurements just like the mean arterial pressure measurements at the 40th, 100th minutes and during the deployment of the graft. Postoperative mortality occurred in 3 (20.0% patients and they all had general anesthesia and they were operated on emergency basis. Postoperative morbidity occurred in four patients that had general anesthesia (acute renal failure, multi-organ failure and pneumonia. The other patient had atrial fibrillation on the 1st postoperative day and was converted to sinus rhythm with amiodarone infusion.Conclusion: Edovascular aortic reconstruction procedures can safely be performed with both general and local anesthesia less invasively compared to open surgery. General anesthesia may be preferred for the better hemodynamic control.

  11. Chylous complications after abdominal aortic surgery.

    Science.gov (United States)

    Haug, E S; Saether, O D; Odegaard, A; Johnsen, G; Myhre, H O

    1998-12-01

    Two patients developed chylous complications following abdominal aortic aneurysm repair. One patient had chylous ascitis and was successfully treated by a peritoneo-caval shunt. The other patient developed a lymph cyst, which gradually resorbed after puncture. Chylous complications following aortic surgery are rare. Patients in bad a general condition should be treated by initial paracentesis and total parenteral nutrition, supplemented by medium-chain triglyceride and low-fat diet. If no improvement is observed on this regimen, the next step should be implementation of a peritoneo-venous shunt, whereas direct ligation of the leak should be reserved for those who are not responding to this treatment. PMID:10204656

  12. Supravalvular aortic stenosis with sudden cardiac death

    Directory of Open Access Journals (Sweden)

    Pradeep Vaideeswar

    2015-01-01

    Full Text Available Sudden cardiac death (SCD most commonly results from previously undiagnosed congenital, acquired, or hereditary cardiac diseases. Congenital aortic valvular, subvalvular, and supravalvular disease with left ventricular outflow tract obstruction is an important preventable cause of sudden death. This report documents sudden death presumably due to acute myocardial ischemia in a young male with an undiagnosed supravalvular aortic stenosis (SVAS due to a rare association of isolation of coronary sinuses of Valsalva. Congenital supravalvular pulmonary stenosis and mitral valvular dysplasia were also present.

  13. Contemporary management of blunt aortic trauma.

    Science.gov (United States)

    Dubose, J J; Azizzadeh, A; Estrera, A L; Safi, H J

    2015-10-01

    Blunt thoracic aortic injury (BTAI) remains a common cause of death following blunt mechanisms of trauma. Among patients who survive to reach hospital care, significant advances in diagnosis and treatment afford previously unattainable survival. The Society for Vascular Surgery (SVS) guidelines provide current best-evidence suggestions for treatment of BTAI. However, several key areas of controversy regarding optimal BTAI care remain. These include the refinement of selection criteria, timing for treatment and the need for long-term follow-up data. In addition, the advent of the Aortic Trauma Foundation (ATF) represents an important development in collaborative research in this field. PMID:25868973

  14. Infective endocarditis following transcatheter aortic valve replacement-

    DEFF Research Database (Denmark)

    Loh, Poay Huan; Bundgaard, Henning; S�ndergaard, Lars

    2013-01-01

    Transcatheter aortic valve replacement (TAVR) can improve the symptoms and prognosis of patients with severe aortic stenosis who, due to a high expected operative risk, would not have otherwise been treated surgically. If these patients develop prosthetic valve endocarditis, their presentations may...... be atypical causing a delay in the diagnosis and treatment. The management is also complicated by their comorbidities, and surgical treatment may not be feasible leading to a significant morbidity and mortality. We describe a case of an 85-year-old man with TAVI prosthetic valve endocarditis...

  15. Abdominal aortic aneurysm demonstrated on renal scintigraphy.

    Science.gov (United States)

    Phisitkul, Sorot; Brian, Susan; Rakvit, Ariwan; Jenkins, Leigh A; Bohannon, W Todd; Harris, Jennifer; Tsikouris, James; Silva, Michael B; Meyerrose, Gary E

    2003-08-01

    A 74-year-old hypertensive woman presented with abdominal discomfort and a pulsatile abdominal mass. Anterior abdominal angiography during cardiac blood pool, and renal scintigraphic imaging demonstrated a large abdominal aortic aneurysm. 1, 2 Before endovascular repair with an aortoiliac endograft, the abdominal aneurysm measured 7.5 x 7.0 cm on abdominal computed tomography. This study demonstrates that a suspected abdominal aortic aneurysm can be confirmed using the addition of anterior abdominal imaging with normal posterior imaging at the time of renal scintigraphy. PMID:12897671

  16. Beveled reversed elephant trunk procedure for complex aortic aneurysm.

    Science.gov (United States)

    Fujikawa, Takuya; Yamamoto, Shin; Sekine, Yuji; Oshima, Susumu; Kasai, Reo; Sasaguri, Shiro

    2016-03-01

    The reversed elephant trunk procedure uses an inverted graft for distal aortic replacement before aortic arch replacement in patients with mega aorta, to reduce the risk in the second stage. However, the conventional technique restricts the maximum diameter of the inverted graft to the aortic graft diameter. We employed a beveled reversed elephant trunk procedure to overcome the discrepancy between graft diameters in a 54-year-old woman with a severely twisted ascending aortic graft and enlarging chronic dissection of the aortic arch and descending thoracic aorta. The patient was discharged with a satisfactory repair and no neurologic deficit. PMID:25406402

  17. Determination Of Plasma Parameters In The PUPR Mirror and Cusp Plasma Machine Via Electrostatic Probe Methods

    Science.gov (United States)

    Meyer, Ryan M.; Rivera, Miguel A.; Colmenares, Franklyn; Leal, David; Rivera, Ramon; Gonzales, Angel; Leal-Quiros, Edbertho

    2006-12-01

    Electrostatic probes are constructed for the PUPR Mirror and Cusp Plasma Machine and preliminary measurements of the plasma parameters are obtained. The machine is cylindrical in shape with two copper coils wound around the machine to provide the necessary mirror or cusp field configuration. The plasma is heated using the electron cyclotron heating method at a frequency of 2.45 GHz. I-V characteristics are obtained using single, double, and emissive Langmuir probes in Argon plasma at approximately 1*10-4 Torr and with approximate field strength of ˜ 0.1T at the point cusp. The single and double Langmuir probes consist of 3.5 mm radius stainless steel disks. Characteristics are obtained for the single and double Langmuir probes using a source meter and programming a voltage sweep while recording the current from the digital readout. The emissive probe is constructed by using a tungsten filament and characteristics are obtained in a manner similar to that described for the single and double Langmuir probes. An emission current is superposed on top of the sweeping signal using a DC power source. An electron temperature of approximately 7.5eV is observed in the plasma at a density of ˜4.0*1014m-3 using the single Langmuir probe. In addition, with the distribution function obtained from the single probe, the plasma potential is observed to be approximately 25-30V. The measurement of 25-30V for the plasma potential is supported by measurements obtained from the emissive probe.

  18. Magnetospheric boundary dynamics: DE 1 and DE 2 observations near the magnetopause and cusp

    International Nuclear Information System (INIS)

    A broad spectrum of particle and field measurements was taken near local noon by the Dynamics Explorer satellites during the magnetic storm of September 6, 1982. While at apogee, DE 1 sampled the magnetospheric boundary layer at mid southern latitudes and, due to the passage of an intense solar wind burst, briefly penetrated into the magnetosheath. In the boundary layer and the adjacent magnetosheath the plasma flow was directed toward dawn. Variance and de Hoffman-Teller analyses of electric and magnetic field data during the magnetopause crossing showed the magnetopause structure to be that of a rotational discontinuity or an intermediate shock with a substantial normal magnetic field component. This is consistent with an open magnetosphere model in which significant magnetic merging occurs at the local time of the spacecraft. The orbit of DE 2 carried it through the morning sector of the low-altitude, southern cusp. The measurements show a well-defined, cusp current system occurring on open magnetic field lines. At both cusp and subcusp latitudes the electric field was equatorward indicating a strongly eastward plasma flow. The boundary between these two regions was marked by the onset of magnetosheath precipitation and an electric field structure containing both poleward and equatorward spikes. The poleward spike has associated field-aligned currents which are closed by Pedersen currents and, from force balance considerations, is interpreted as the signature of a magnetic merging event at the magnetopause. The equatorward spike has the characteristics of a down-coming and reflected Alfven wave packet of finite dimensions. The high-altitude measurements suggest that the dayside boundary layer is made up of closed magnetic flux tubes, a large fraction of which drift to the magnetopause where merging with the IMF occurs

  19. Direct determination of IMF B-Y-related cusp current systems, using SuperDARN radar and multiple ground magnetometer data: A link to theory on cusp current origin

    DEFF Research Database (Denmark)

    Amm, O.; Engebretson, M.J.; Greenwald, R.A.; Luhr, H.; Moretto, T.

    We analyze an ionospheric "enhanced convection event" in the cusp on November 13, 1996, at 1900 UT, by using data of the SuperDARN radar, and of the IMAGE, Greenland, MACCS and CANOPUS magnetometer arrays; and from other magnetometer stations. The event occurs similar to 20 minutes after a...... system with respect to the open-closed field line boundary. The location of this boundary is inferred from DMSP F10 satellite data. The center of our resulting current system is located clearly poleward of the open-closed field line boundary, thus favoring the idea of Lee et al. [1985] that the cusp FACs...... are caused by a rotational discontinuity of the magnetic field at the magnetopause. In contrast, the idea of Clauer and Banks [1986] that a mapping of the solar wind E-z component to the ionosphere is responsible for the cusp current system is not supported....

  20. Cusped and Smooth Solitons for the Generalized Camassa-Holm Equation on the Nonzero Constant Pedestal

    Directory of Open Access Journals (Sweden)

    Dong Li

    2014-01-01

    Full Text Available We investigate the traveling solitary wave solutions of the generalized Camassa-Holm equation ut - uxxt + 3u2ux=2uxuxx + uuxxx on the nonzero constant pedestal limξ→±∞⁡uξ=A. Our procedure shows that the generalized Camassa-Holm equation with nonzero constant boundary has cusped and smooth soliton solutions. Mathematical analysis and numerical simulations are provided for these traveling soliton solutions of the generalized Camassa-Holm equation. Some exact explicit solutions are obtained. We show some graphs to explain our these solutions.

  1. Quantum Spectral Curve for a cusped Wilson line in {N}=4 SYM

    Science.gov (United States)

    Gromov, Nikolay; Levkovich-Maslyuk, Fedor

    2016-04-01

    We show that the Quantum Spectral Curve (QSC) formalism, initially formulated for the spectrum of anomalous dimensions of all local single trace operators in {N}=4 SYM, can be extended to the generalized cusp anomalous dimension for all values of the parameters. We find that the large spectral parameter asymptotics and some analyticity properties have to be modified, but the functional relations are unchanged. As a demonstration, we find an all-loop analytic expression for the first two nontrivial terms in the small |ϕ ± θ | expansion. We also present nonperturbative numerical results at generic angles which match perfectly 4-loop perturbation theory and the classical string prediction.

  2. Root abnormalities, talon cusps, dentes invaginati with reduced alveolar bone levels: case report.

    LENUS (Irish Health Repository)

    McNamara, C M

    1998-03-01

    This is a case report of a Caucasian female who presented with an unusual combination of dental anomalies: short roots on the maxillary central incisors and premolars, talon cusps, dentes invaginati, low alveolar bone heights, tubercles of Carabelli on the maxillary first and second permanent molars, with pyramidal root morphology in three of the second permanent molars. None of the anomalies alone are particularly uncommon but they have not previously been reported together. The occurrence of the anomalies is probably incidental as the conditions are aetiologically unrelated.

  3. Application of Cusp Catastrophe Theory to U.S. Stock Market Crashes

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Vošvrda, Miloslav

    Bratislava: University of Economics in Bratislava, 2008, s. 19-27 ISBN 978-80-8078-217-7. [Quantitative Methods in Economics: Multiplie Criteria Decision Making XIV. Tatranská Lomnica (SK), 05.07.2008-07.07.2008] R&D Projects: GA ČR(CZ) GA402/06/0990; GA ČR(CZ) GA402/08/0107 Grant ostatní: MŚMT(CZ) LC06075 Institutional research plan: CEZ:AV0Z10750506 Keywords : cusp catastrophe * bifurcation, * singularity * stock market crash * nonlinear dynamics Subject RIV: AH - Economics

  4. Magnetosheath-ionspheric plasma interactions in the cusp/cleft. 2: Mesoscale particle simulations

    Science.gov (United States)

    Winglee, R. M.; Menietti, J. D.; Lin, C. S.

    1993-11-01

    Ionospheric plasma flowing out from the cusp can be an important source of plasma to the magnetosphere. One source of free energy that can drive this outflow is the injection of magnetosheath plasma into the cusp. Two-dimensional (three velocity) mesoscale particle simulations are used to investigate the particle dynamics in the cusp during southward interplanetary magnetic field. This mesoscale model self-consistently incorporates (1) global influences such as the convection of plasma across the cusp, the action of the mirror force, and the injection of the magnetosheath plasma, and (2) wave-particle interactions which produce the actual coupling between the magnetosheath and ionospheric plasmas. It is shown that, because the thermal speed of the electrons is higher than the bulk motion of the magnetosheath plasma, an upward current is formed on the equatorward edge of the injection region with return currents on either side. However, the poleward return currents are the stronger due to the convection and mirroring of many of the magnetosheath electrons. The electron distribution in this latter region evolves from upward directed streams to single-sided loss cones or possibly electron conics. The ion distribution also shows a variety of distinct features that are produced by spatial and/or temporal effects associated with varying convection patterns and wave-particle interactions. On the equatorward edge the distribution has a downflowing magnetosheath component and an upflowing cold ionospheric component due to continuous convection of ionospheric plasma into the region. In the center of the magnetosheath region, heating from the development of an ion-ion streaming instability causes the suppression of the cold ionospheric component and the formation of downward ionospheric streams. Further poleward there is velocity filtering of ions with low pitch angles, so that the magnetosheath ions develop a ring-beam distribution and the ensuing wave instabilities generate

  5. Isotope separation in the reflected ion beam in a with a cusp magnetic field

    International Nuclear Information System (INIS)

    The isotope separation in a reflected ion beam injected into a cusp magnetic field has been considered. The magnetic field configuration was formed by two rings with oppositely directed currents. The motion of the particles entering the system and reflected by the increasing magnetic field of the second ring is numerically calculated. A possibility for reflected particles to be separated in the radial direction is shown. This effect allows an annular ion source to be used, which leads to an increase in the total current and the performance of the system

  6. Gravitational lens equation. Critical solutions and magnification near folds and cusps

    CERN Document Server

    Alexandrov, A N; Zhdanov, V I

    2013-01-01

    We study approximate solutions of the gravitational lens equation and corresponding lens magnification factor near the critical point. This consideration is based on the Taylor expansion of the lens potential in powers of coordinates and an introduction of a proximity parameter characterising the closeness of a point source to the caustic. Second-order corrections to known approximate solutions and magnification are found in case of a general fold point. The first-order corrections near a general cusp are found as well. Key words: gravitational lensing, methods: analytical

  7. Flow with boiling in four-cusp channels simulating damaged core in PWR type reactors

    International Nuclear Information System (INIS)

    The study of subcooled nucleate flow boiling in non-circular channels is of great importance to engineering applications in particular to Nuclear Engineering. In the present work, an experimental apparatus, consisting basically of a refrigeration system, running on refrigerant-12, has been developed. Preliminary tests were made with a circular tube. The main objective has been to analyse subcooled flow boiling in four-cusp channels simulating the flow conditions in a PWR core degraded by accident. Correlations were developed for the forced convection film coefficient for both single-phase and subcooled flow boiling. The incipience of boiling in such geometry has also been studied. (author)

  8. Polar spacecraft observations of the turbulent outer cusp/magnetopause boundary layer of Earth

    OpenAIRE

    J. S. Pickett; Menietti, J. D.; J. H. Dowell; Gurnett, D.A.; Scudder, J. D.

    1999-01-01

    The orbit of the Polar spacecraft has been ideally suited for studying the turbulent region of the cusp that is located near or just outside the magnetopause current sheet at 7-9 RE. The wave data obtained in this region show that electromagnetic turbulence is dominant in the frequency range 1-10 Hz. The waves responsible for this turbulence usually propagate perpendicular to the local magnetic field and have an index of refraction that generally falls between the estimated cold plasma theore...

  9. The correlations of ions density with geomagnetic activity and solar dynamic pressure in cusp region

    Institute of Scientific and Technical Information of China (English)

    GUO JianGuang; SHI JianKui; ZHANG TieLong; LIU ZhenXing; A. FAZAKERLEY; H. R(E)ME; Ⅰ. DANDOURAS; E. LUCEK

    2007-01-01

    A statistical study of the properties of ions (O+, He+ and H+) measured by the Cluster-Ⅱ in cusp region as a function of the solar wind dynamic pressure and geomagnetic index Kp respectively was made during the summer and fall of 2001 -2003. The main results are that: (1) O+ ion density responds in a significant way to geomagnetic index Kp, and He+ ion density is not correlated with geomagnetic index Kp,both of them have a significant positive correlation with solar wind dynamic pressure; (2) H+ ion density is also observed to increase with solar wind dynamic pressure, and not correlated with geomagnetic index Kp.

  10. Cardiovascular magnetic resonance of quinticuspid aortic valve with aortic regurgitation and dilated ascending aorta

    OpenAIRE

    Zhang Zhaoqi; Zhang Lijun; Meng Yanfeng; Wang Yongmei; Yang Xiaoming

    2009-01-01

    Abstract We report a rare case of a quinticuspid aortic valve associated with regurgitation and dilation of the ascending aorta, which was diagnosed and post-surgically followed up by cardiovascular magnetic resonance and dual source computed tomography.

  11. First transcatheter aortic valve implantation for severe pure aortic regurgitation in Asia.

    Science.gov (United States)

    Chiam, Paul Toon-Lim; Ewe, See Hooi; Chua, Yeow Leng; Lim, Yean Teng

    2014-02-01

    Transcatheter aortic valve implantation (TAVI) has become the standard of care for inoperable patients with symptomatic severe aortic stenosis (AS), and an alternative to open aortic valve replacement for patients at high surgical risk. TAVI has also been performed in several groups of patients with off-label indications such as severe bicuspid AS, and as a valve-in-valve therapy for a degenerated surgical bioprosthesis. Although TAVI with CoreValve® prosthesis is technically challenging, and global experience in the procedure is limited, the procedure could be a treatment option for well-selected patients with severe pure aortic regurgitation (AR). Herein, we report Asia's first case of TAVI for severe pure AR in a patient who was at extreme surgical risk, with good clinical outcome at six months. PMID:24570320

  12. Computed tomography angiography of hybrid thoracic endovascular aortic repair of the aortic arch.

    Science.gov (United States)

    Akhtar, Nila J; Oderich, Gustavo S; Vrtiska, Terri J; Williamson, Eric E; Araoz, Philip A

    2013-05-01

    Endovascular repair of the aorta has traditionally been limited to the abdominal aorta and, more recently, the descending thoracic aorta. However, recently hybrid repairs (a combination of open surgical and endovascular repair) have made endovascular repair of the aortic arch possible. Hybrid repair of the aortic arch typically involves an open surgical debranching procedure that allows for revascularization of the aortic arch vessels and subsequent endovascular stent placement. These approaches avoid the deep hypothermic circulatory arrest required for full, open surgical repair of the aortic arch. In hybrid repairs, the stent landing zone determines which branch vessels will be covered and therefore need revascularization. This article will review the preprocedure assessment with computed tomography angiography, techniques for revascularization and postprocedure complications. PMID:23621141

  13. Factors influencing long-term survival after aortic valve replacement.

    Directory of Open Access Journals (Sweden)

    Shigenobu,Masaharu

    1980-06-01

    Full Text Available In the aortic stenosis group, the left ventricular (LV muscle mass index was a good parameter for predicting the prognosis. Associated mitral valve disease had no influence on long term survival after aortic valve replacement. In the aortic insufficiency group, associated mitral valve disease had a marked influence on the results of aortic valve replacement. In general, the aortic insufficiency group had less clinical improvement postoperatively than the aortic stenosis group. In the annuloaortic ectasia group, left ventricular enddiastolic pressure (LVEDP might be the predictor to the prognosis. This group had the worst prognosis, of the three groups. Early operation should be considered for patients who have no, or only mild symptoms of, aortic valve disease.

  14. Anatomics Knowledges of Aortic Root in the Transcatheter Aortic Valve Implantation.

    Directory of Open Access Journals (Sweden)

    Marcelo Cerezo

    2010-12-01

    Full Text Available The Aortic Valve is a valvular system that bears different high pressure forces. It takes part of a complex structure called Aortic Root. Nowadays, anatomic knowledge has taken a preponderant role, due to the use of the Transcatether Aortic Valve Implant (TAVI. To describe the patient´s characteristics which exclude them of the TAVI for anatomic reasons in cadaveric dissections and transthoracic echocardiograms. A descriptive retrospective analysis of 67 individuals was performed and divided into two groups. Group A: Formalized cadaveric dissections with hypertrofic hearts and aortic sclerosis signs from the Chair A of Anatomy of the University of La Plata (UNLP. Group B: Transthoracic Echocardiograms realized at the San Martín Hospital of La Plata between January 2005 and December 2009. Out of 67 individuals assessed, 17 (25% had one or more contraindications for TAVI. Five on Group A (36%, and 12 on Group B (23%. The most common anatomic contraindication was the Ascending Aortic diameter less than 30mm and the aortic annulus less than 20mm, following to the RAo-TSVI Angle more than 145° (2 to Group A, and 4 to Group B and the Septal thickness more than 17mm (no one to Group A, and 3 to Group B. Only just one individual was found with a low implant left coronary artery in the Group A avoiding TAVI. According to this study, the anatomic contraindications to realize TAVI are frequent due to the diagnosis devices available at the moment. The anatomic aortic root knowledge and the aortic valve interindividual variability will allow the improvement of the manufactured devices made in the market.

  15. Marfan syndrome in children and adolescents: predictive and prognostic value of aortic root growth for screening for aortic complications

    OpenAIRE

    Groenink, M; Rozendaal, L; Naeff, M.S.J.; Hennekam, R.C.M.; Hart, A.A.M.; Wall; Mulder, B.J.M.

    1998-01-01

    Objective—To assess and measure the diagnostic and prognostic value of individual aortic root growth in children and adolescents with Marfan syndrome.
Design—From 1983 to 1996, 250 children were screened for Marfan syndrome. Serial echocardiographic aortic root measurements of 123 children (57 Marfan, 66 control) were available for evaluation of aortic root growth. Aortic root diameters were correlated with body surface area. Based on individual growth of the aortic root a discrimination form...

  16. The ascending aortic image quality and the whole aortic radiation dose of high-pitch dual-source CT angiography

    OpenAIRE

    Liu, Ying; Xu, Jian; Jian LI; Ren, Jing; LIU, HONGTAO; Xu, Junqing; Wei, Mengqi; Hao, Yuewen; Zheng, Minwen

    2013-01-01

    Background Aortic dissection is a lift-threatening medical emergency associated with high rates of morbidity and mortality. The incidence rate of aortic dissection is estimated at 5 to 30 per 1 million people per year. The prompt and correct diagnosis of aortic dissection is critical. This study was to compare the ascending aortic image quality and the whole aortic radiation dose of high-pitch dual-source CT angiography and conventional dual-source CT angiography. Methods A total of 110 conse...

  17. Demonstration of fold and cusp catastrophes in an atomic cloud reflected from an optical barrier in the presence of gravity

    CERN Document Server

    Rosenblum, Serge; Shomroni, Itay; Kaner, Roy; Arusi-Parpar, Talya; Raz, Oren; Dayan, Barak

    2013-01-01

    We experimentally demonstrate first-order (fold) and second-order (cusp) catastrophes in the density of an atomic cloud reflected from an optical barrier in the presence of gravity, and show their corresponding universal asymptotic behavior. The cusp point enables robust, field-free refocusing of an expanding atomic cloud with a wide velocity distribution. Specifically, the density attained at the cusp point in our experiment reached 65% of the peak density of the atoms in the trap prior to their release. We thereby add caustics to the various phenomena with parallels in optics that can be harnessed for manipulation of cold atoms. The structural stability of catastrophes provides inherent robustness against variations in the system's dynamics and initial conditions, making them suitable for manipulation of atoms under imperfect conditions and limited controllability.

  18. Holographic cusped Wilson loops in q-deformed AdS5×S5 spacetime

    International Nuclear Information System (INIS)

    In this paper, a minimal surface in q-deformed AdS5×S5 with a cusp boundary is studied in detail. This minimal surface is dual to a cusped Wilson loop in dual field theory. We find that the area of the minimal surface has both logarithmic squared divergence and logarithmic divergence. The logarithmic squared divergence cannot be removed by either Legendre transformation or the usual geometric substraction. We further make an analytic continuation to the Minkowski signature, taking the limit such that the two edges of the cusp become light-like, and extract the anomalous dimension from the coefficient of the logarithmic divergence. This anomalous dimension goes back smoothly to the results in the undeformed case when we take the limit that the deformation parameter goes to zero

  19. Effect of the variable cross-section channel on performance of a cusped field thruster at low power

    International Nuclear Information System (INIS)

    The cusped field thruster has drawn much attention from many institutions due to its wide thrust range, high impulse, and long lifetime. However, lots of experimental results reveal that the cusped field thruster at low power has a poor performance. A cusped field thruster with a variable cross-section channel by putting a ceramic spacer in the channel is introduced in this paper, aimed at improving the thruster performance at low power. The DSMC results validate that the upstream atom density can be increased by a spacer, especially near the wall. Based on simulated results, spacers are put into different positions of the channel. The experimental results show that a suitable spacer can enhance thruster performance at low power, which can be confirmed by the results that the anode efficiency can achieve 40% at 400 V anode voltage and 20 sccm gas flow rate by contrast to 35% without a spacer under the same condition. (paper)

  20. Aorto-right atrial fistula after ascending aortic replacement or aortic value replacement

    International Nuclear Information System (INIS)

    Objective: To evaluate the CT features of aorto-right atrial fistula after aortic valve replacement (AVR) or ascending aortic replacement. Methods: Eighty-seven patients with aortic-right atrial fistula underwent CT after operation. The CT features were retrospectively analyzed. Fistula was measured according to maximum width of the shunt. Results: Aorto-right atrial fistula was detected in 87 patients after aortic valve replacement or ascending aortic replacement by CT scan. Among them, 25 patients were diagnosed as mild aorto-right atrial fistula, 47 patients as moderate, and 15 patients as severe. Thirty-seven patients underwent follow-up CT.Among them, 10 patients with mild to moderate aorto-right atrial fistula were considered to have complete regression, 8 patients with mild aorto-right atrial fistula considered to have incomplete regression, 14 patients with mild to moderate aorto-right atrial fistula considered to have stable condition, and 5 patients with moderate aorto-right atrial fistula considered to have progression at the 3-month follow-up. Conclusion: CT is a useful tool for defining aorto-right atrial fistula after AVR or ascending aortic replacement and for evaluating it in follow-up. (authors)

  1. Ultrasonic delineation of aortic microstructure: The relative contribution of elastin and collagen to aortic elasticity

    Science.gov (United States)

    Marsh, Jon N.; Takiuchi, Shin; Lin, Shiow Jiuan; Lanza, Gregory M.; Wickline, Samuel A.

    2004-05-01

    Aortic elasticity is an important factor in hemodynamic health, and compromised aortic compliance affects not only arterial dynamics but also myocardial function. A variety of pathologic processes (e.g., diabetes, Marfan's syndrome, hypertension) can affect aortic elasticity by altering the microstructure and composition of the elastin and collagen fiber networks within the tunica media. Ultrasound tissue characterization techniques can be used to obtain direct measurements of the stiffness coefficients of aorta by measurement of the speed of sound in specific directions. In this study we sought to define the contributions of elastin and collagen to the mechanical properties of aortic media by measuring the magnitude and directional dependence of the speed of sound before and after selective isolation of either the collagen or elastin fiber matrix. Formalin-fixed porcine aortas were sectioned for insonification in the circumferential, longitudinal, or radial direction and examined using high-frequency (50 MHz) ultrasound microscopy. Isolation of the collagen or elastin fiber matrices was accomplished through treatment with NaOH or formic acid, respectively. The results suggest that elastin is the primary contributor to aortic medial stiffness in the unloaded state, and that there is relatively little anisotropy in the speed of sound or stiffness in the aortic wall.

  2. Endovascular aortic repair: first twenty years.

    Science.gov (United States)

    Koncar, Igor; Tolić, Momcilo; Ilić, Nikola; Cvetković, Slobodan; Dragas, Marko; Cinara, Ilijas; Kostić, Dusan; Davidović, Lazar

    2012-01-01

    Endovascular aortic/aneurysm repair (EVAR) was introduced into clinical practice at the beginning of the nineties. Its fast development had a great influence on clinicians, vascular surgeons and interventional radiologists, educational curriculums, patients, industry and medical insurance. The aim of this paper is to present the contribution of clinicians and industry to the development and advancement of endovascular aortic repair over the last 20 years. This review article presents the development of EVAR by focusing on the contribution of physicians, surgeons and interventional radiologists in the creation of the new field of vascular surgery termed hybrid vascular surgery, and also the contribution of technological advancement by a significant help of industrial representatives--engineers and their counselors. This article also analyzes studies conducted in order to compare the successfulness of EVAR with up-to-now applied open surgical repair of aortic aneurysms, and some treatment techniques of other aortic diseases. During the first two decades of its development the EVAR method was rapidly progressing and was adopted concurrently with the expansion of technology. Owing to large randomized studies, early and long-term results indicate specific complications of this method, thus influencing further technological improvement and defining risk patients groups in whom the use of the technique should be avoided. Good results are insured only in centers, specialized in vascular surgery, which have on their disposal adequate conditions for solving all complications associated with this method. PMID:23350259

  3. Natural history of abdominal aortic aneurysm

    DEFF Research Database (Denmark)

    Perko, M J; Schroeder, T V; Olsen, P S;

    1993-01-01

    During a 10-year period in which 735 patients presented with abdominal aortic aneurysms to our clinic, 63 were not offered operative treatment. The primary reason for choosing conservative treatment was concomitant diseases that increased the risk of operation. After 2 years of followup, half of ...

  4. [Ascending-descending Aortic Bypass and Aortic Valve Replacement for Aortic Coarctation with Bicuspid Aortic Valve and an Aberrant Right Subclavian Artery;Report of a Case].

    Science.gov (United States)

    Asano, Ryota; Nakano, Kiyoharu; Kodera, Kojiro; Sato, Atsuhiko; Kataoka, Go; Tatsuishi, Wataru; Kubota, Sayaka; Namiki, Shigetaka; Suzuki, Seiya

    2015-08-01

    A 53-year-old woman was developed congestive heart failure. She was diagnosed as having aortic coarctation, incompetent bicuspid aortic valve and an aberrant right subclavian artery by using echocardiography and enhanced computed tomography. Ankle brachial pressure index(ABI)in the right was 0.71 and 0.69 in the left. Blood pressure of the right arm was 60 mmHg lower than that of the left arm. To avoid perioperative adverse cardiac events due to a 2-staged operation, we performed ascending-descending aortic bypass and aortic valve replacement simultaneously through a median sternotomy. The heart was retracted cranially, and a vascular prosthesis was anastomosed to the descending aorta just above the diaphragm in an end-to-side manner. Then the graft was placed curvilinearly around the right atrium and was anastomosed to the ascending aorta. After the operation, the right and left ABI increased to 0.90 and 0.98 respectively. There was no pressure difference between the arms. The postoperative course was uneventful. PMID:26329712

  5. Global Strain in Severe Aortic Valve Stenosis

    DEFF Research Database (Denmark)

    Dahl, Jordi S; Videbæk, Lars; Poulsen, Mikael K;

    2012-01-01

    Score, history with ischemic heart disease and ejection fraction. CONCLUSIONS: -In patients with symptomatic severe aortic stenosis undergoing AVR reduced GLS provides important prognostic information beyond standard risk factors. Clinical Trial Registration-URL: http://www.clinicaltrial.gov. Unique identifier...

  6. Outcomes After Elective Aortic Aneurysm Repair

    DEFF Research Database (Denmark)

    de la Motte, L; Jensen, L P; Vogt, K;

    2013-01-01

    OBJECTIVE: To assess outcomes after treatment for asymptomatic abdominal aortic aneurysm (AAA) in Denmark in a period when both open surgery (OR) and endoluminal repair (EVAR) have been routine procedures. METHODS: We performed a retrospective nationwide cohort study of patients treated for asymp...

  7. Idiopathic Aortic Root to Right Atrial Fistula.

    Science.gov (United States)

    Campisi, Salvatore; Cluzel, Armand; Vola, Marco; Fuzellier, Jean Francois

    2016-06-01

    An aorta to right atrium fistula is rare. We report a case of idiopathic aortic root to right atrial fistula with right heart failure and review the literature. doi: 10.1111/jocs.12751 (J Card Surg 2016;31:373-375). PMID:27109166

  8. Multimodality Imaging Approach towards Primary Aortic Sarcomas Arising after Endovascular Abdominal Aortic Aneurysm Repair: Case Series Report.

    Science.gov (United States)

    Kamran, Mudassar; Fowler, Kathryn J; Mellnick, Vincent M; Sicard, Gregorio A; Narra, Vamsi R

    2016-06-01

    Primary aortic neoplasms are rare. Aortic sarcoma arising after endovascular aneurysm repair (EVAR) is a scarce subset of primary aortic malignancies, reports of which are infrequent in the published literature. The diagnosis of aortic sarcoma is challenging due to its non-specific clinical presentation, and the prognosis is poor due to delayed diagnosis, rapid proliferation, and propensity for metastasis. Post-EVAR, aortic sarcomas may mimic other more common aortic processes on surveillance imaging. Radiologists are rarely knowledgeable about this rare entity for which multimodality imaging and awareness are invaluable in early diagnosis. A series of three pathologically confirmed cases are presented to display the multimodality imaging features and clinical presentations of aortic sarcoma arising after EVAR. PMID:26721588

  9. Endovascular treatment of thoracic aortic diseases

    Directory of Open Access Journals (Sweden)

    Davidović Lazar

    2013-01-01

    Full Text Available Bacground/Aim. Endovascular treatment of thoracic aortic diseases is an adequate alternative to open surgery. This method was firstly performed in Serbia in 2004, while routine usage started in 2007. Aim of this study was to analyse initial experience in endovacular treatment of thoracic aortic diseses of three main vascular hospitals in Belgrade - Clinic for Vascular and Endovascular Surgery of the Clinical Center of Serbia, Clinic for Vascular Surgery of the Military Medical Academy, and Clinic for Vascular Surgery of the Institute for Cardiovascular Diseases “Dedinje”. Methods. Between March 2004. and November 2010. 41 patients were treated in these three hospitals due to different diseases of the thoracic aorta. A total of 21 patients had degenerative atherosclerotic aneurysm, 6 patients had penetrating aortic ulcer, 6 had posttraumatic aneurysm, 4 patients had ruptured thoracic aortic aneurysm, 1 had false anastomotic aneurysm after open repair, and 3 patients had dissected thoracic aneurysm of the thoracoabdominal aorta. In 15 cases the endovascular procedure was performed as a part of the hybrid procedure, after carotidsubclavian bypass in 4 patients and subclavian artery transposition in 1 patient due to the short aneurysmatic neck; in 2 patients iliac conduit was used due to hypoplastic or stenotic iliac artery; in 5 patients previous reconstruction of abdominal aorta was performed; in 1 patient complete debranching of the aortic arch, and in 2 patients visceral abdominal debranching were performed. Results. The intrahospital mortality rate (30 days was 7.26% (3 patients with ruptured thoracic aneurysms died. Endoleak type II in the first control exam was revealed in 3 patients (7. 26%. The patients were followed up in a period of 1-72 months, on average 29 months. The most devastating complication during a followup period was aortoesofageal fistula in 1 patient a year after the treatment of posttraumatic aneurysm. Conversion was

  10. Are small-scale field-aligned currents and magneto sheath-like particle precipitation signatures of the same low-altitude cusp?

    DEFF Research Database (Denmark)

    Watermann, J.; Stauning, P.; Luhr, H.;

    2009-01-01

    satellites were converted into AACGM coordinates, and the geomagnetic latitude of the cusp boundaries (as indicated by precipitating particles and small-scale field-aligned currents) set in relation to the IMF-B-z dependent latitude of the equatorward boundary of the statistical cusp. We find that the...

  11. Transfer coefficients in a four-cusp duct simulating a typical nuclear reactor channel degraded by accident

    International Nuclear Information System (INIS)

    An experimental study on forced convection in a four-cusp duct simulating a typical nuclear reactor channel degraded by accident is presented. Transfer coefficients were obtained by using the analogy between heat and mass tranfer, with the naphtalene sublimation technique. The experiment consisted in forcing air past a four-cusp naphthalene moulded duct. Mass transfer coefficients were determined in nondimensional form as Sherwood number. Experimental curves correlating the Sherwood number with a nondimensional length, x+, were obtained for Reynolds number varying from 891 to 30.374. This range covers typical flow rates that are expected to exist in a degraded nuclear reactor core. (Author)

  12. Cluster observations of magnetic field fluctuations in the high-altitude cusp

    Directory of Open Access Journals (Sweden)

    K. Nykyri

    2004-07-01

    Full Text Available High-resolution (22 vector/s magnetic field data from Cluster FGM instrument are presented for the high-altitude cusp crossing on 17 March 2001. Despite the quiet solar wind conditions, the cusp was filled with magnetic field turbulence for much of the crossing. Large-scale fluctuations show some correlation between spacecraft but the higher frequency fluctuations show no correlation, indicating that the length scales of these waves are smaller than the spacecraft separation (500km. In many intervals, there are clear peaks in the wave power around the ion cyclotron frequency (~1Hz, and there is some evidence for waves at the first harmonic of this frequency. Both left- and right-hand polarised waves are found, with angles of propagation with respect to the ambient magnetic field that range from parallel to perpendicular. The regions of enhanced magnetic field fluctuations appear to be associated with plasma flows possibly originating from a lobe reconnection site. The most coherent, long lasting wave trains with frequencies close to local ion cyclotron frequency occur at a boundary between a sheared flow and a stagnant plasma.

  13. Research on traffic flow forecasting model based on cusp catastrophe theory

    Institute of Scientific and Technical Information of China (English)

    张亚平; 裴玉龙

    2004-01-01

    This paper intends to describe the relationship between traffic parameters by using cusp catastrophe theory and to deduce highway capacity and corresponding speed forecasting value through suitable transformation of catastrophe model. The five properties of a catastrophe system are outlined briefly, and then the data collected on freeways of Zhujiang River Delta, Guangdong province, China are examined to ascertain whether they exhibit qualitative properties and attributes of the catastrophe model. The forecasting value of speed and capacity for freeway segments are given based on the catastrophe model. Furthermore, speed-flow curve on freeway is drawn by plotting out congested and uncongested traffic flow and the capacity value for the same freeway segment is also obtained from speed-flow curve to test the feasibility of the application of cusp catastrophe theory in traffic flow analysis. The calculating results of catastrophe model coincide with those of traditional traffic flow models regressed from field observed data, which indicates that the deficiency of traditional analysis of relationship between speed, flow and occupancy in two-dimension can be compensated by analysis of the relationship among speed, flow and occupancy based on catastrophe model in three-dimension. Finally, the prospects and problems of its application in traffic flow research in China are discussed.

  14. NATO Advanced Research Workshop on The Morphology and Dynamics of the Polar Cusp

    CERN Document Server

    Egeland, Alv

    1985-01-01

    These proceedings are based upon introductory talks, research reports and discussions from the NATO Advanced Workshop on the "Morphology and Dynamics of the Polar Cusp", held at Lillehammer, Norway, 7-12 May, 1984. The upper atmosphere at high latitudes is called the "Earth's win­ dow to outer space". Through various electrodynamic coupling process­ es as well as through direct transfer of particles many geophysical effects displayed there are direct manifestations of phenomena occurring in the deep space. The high latitude ionosphere will also exert a feedback on the regions of the magnetosphere and atmosphere to which it is coupled, acting as a momentum and energy source and sink, and a source of particles. Of particular interest are the sections of the near space known as the Polar Cusp. A vast portion of the earth's magnetic field envelope is electrically connected to these regions. This geometry results in a spatial mapping of the magnetospheric pro­ cesses and a focusing on to the ionosphere. In the ...

  15. Magnetosheath plasma precipitation in the polar cusp and its control by the interplanetary magnetic field

    International Nuclear Information System (INIS)

    Magnetosheath particle precipitation in the polar cusp region is studied based on Viking hot plasma data obtained on meridional cusp crossings. Two distinctively different regions are commonly encountered on a typical pass. One region is characterized by high-density particle precipitation, with an ion population characterized by a convecting Maxwellian distribution. Typical magnetosheath parameters are inferred for the spectrum of the source population. The spectral shape of the ion population encountered in the second region suggests that here the magnetosheath ions have been energized by about 1 keV, corresponding to an ion velocity gain of about twice the magnetosheath Alfven velocity. The location of the region containing the accelerated plasma is dependent on the IMF Bz component. For southward IMF the acceleration region is bounded by the ring current population on the equatorward side and by the unaccelerated magnetosheath plasma precipitation on the poleward side. For northward IMF the region is located at the poleward edge of the region with unaccelerated precipitation. The accelerated ion population is obviously transported duskward (dawnward) for a dawnward (duskward) directed IMF. These observations are interpreted as evidence for plasma acceleration due to magnetopause current sheet disruptions/merging of magnetospheric and interplanetary magnetic flux tubes

  16. Cluster observations of bounday layer structure and a flux transfer event near the cusp

    Directory of Open Access Journals (Sweden)

    R. C. Fear

    2005-10-01

    Full Text Available On the 25th January 2002 between 10:00 and 12:00 UT, the four Cluster spacecraft passed through the northern high-latitude cusp, the dayside magnetosphere and into the magnetosheath in a linear formation. In the magnetosphere the PEACE electron spectrometers on the four spacecraft all observed a series of transient bursts of magnetosheath-like plasma, but without bipolar magnetic signatures in the magnetopause normal component as might be expected if the plasma had been injected by transient reconnection (flux transfer events – FTEs. Reordering the data using the magnetopause transition parameter reveals that these plasma observations, the related variations in the magnetic field and the balance of magnetic and thermal gas pressures are consistent with transient entries into a stable high-latitude boundary layer structure. However, once some of the spacecraft entered the magnetosheath, FTE signatures were observed outside the magnetopause at the same time as some of the boundary layer entries occurred at the other spacecraft inside. Thus, (a the lack of a bipolar BN signature is inconsistent with the traditional picture of a magnetospheric FTE, and (b the cause of the observed entry of the spacecraft into the boundary layer (pressure pulse or passing magnetosheath FTE can only be determined by spacecraft observations in the magnetosheath.

    Keywords. Magnetospheric physics (Magnetopause, cusp and bondary layers; Solar wind- magnetosphere interactions; Magnetosheath

  17. Distinguishing dark matter stabilization symmetries using multiple kinematic edges and cusps

    International Nuclear Information System (INIS)

    We emphasize that the stabilizing symmetry for dark matter (DM) particles does not have to be the commonly used parity (Z2) symmetry. We therefore examine the potential of the colliders to distinguish models with parity stabilized DM from models in which the DM is stabilized by other symmetries. We often take the latter to be a Z3 symmetry for illustration. We focus on signatures where a single particle, charged under the DM stabilization symmetry decays into the DM and standard model (SM) particles. Such a Z3-charged mother particle can decay into one or two DM particles along with the same SM particles. This can be contrasted with the decay of a Z2-charged mother particle, where only one DM particle appears. Thus, if the intermediate particles in these decay chains are off-shell, then the reconstructed invariant mass of the SM particles exhibits two kinematic edges for the Z3 case but only one for the Z2 case. For the case of on-shell intermediate particles, distinguishing the two symmetries requires more than the kinematic edges. In this case, we note that certain decay chain topologies of the mother particle which are present for the Z3 case (but absent for the Z2 case) generate a cusp in the invariant mass distribution of the SM particles. We demonstrate that this cusp is generally invariant of the various spin configurations. We further apply these techniques within the context of explicit models.

  18. Contradiction between strong lensing statistics and a feedback solution to the cusp/core problem

    CERN Document Server

    Chen, Da-Ming

    2008-01-01

    Standard cosmology has many successes on large scales, but faces some fundamental difficulties on small, galactic scales. One such difficulty is the cusp/core problem. High resolution observations of the rotation curves for dark matter dominated low surface brightness (LSB) galaxies imply that galactic dark matter halos have a density profile with a flat central core, whereas N-body structure formation simulations predict a divergent (cuspy) density profile at the center. It has been proposed that this problem can be resolved by stellar feedback driving turbulent gas motion that erases the initial cusp. However, strong gravitational lensing prefers a cuspy density profile for galactic halos. In this paper, we use the most recent high resolution observations of the rotation curves of LSB galaxies to fit the core size as a function of halo mass, and compare the resultant lensing probability to the observational results for the well defined combined sample of the Cosmic Lens All-Sky Survey (CLASS) and Jodrell Ba...

  19. Automatic measurement of cusps in 2.5D dental images

    Science.gov (United States)

    Wolf, Mattias; Paulus, Dietrich W.; Niemann, Heinrich

    1996-01-01

    Automatic reconstruction of occlusal surfaces of teeth is an application which might become more and more urgent due to the toxicity of amalgam. Modern dental chairside equipment is currently restricted to the production of inlays. The automatic reconstruction of the occlusal surface is presently not possible. For manufacturing an occlusal surface it is required to extract features from which it is possible to reconstruct destroyed teeth. In this paper, we demonstrate how intact upper molars can be automatically extracted in dental range and intensity images. After normalization of the 3D location, the sizes of the cusps are detected and the distances between them are calculated. In the presented approach, the detection of the upper molar is based on a knowledge-based segmentation which includes anatomic knowledge. After the segmentation of the interesting tooth the central fossa is calculated. The normalization of the spatial location is archieved by aligning the detected fossa with a reference axis. After searching the cusp tips in the range image the image is resized. The methods have been successfully tested on 60 images. The results have been compared with the results of a dentist's evaluation on a sample of 20 images. The results will be further used for automatic production of tooth inlays.

  20. Calculation of electron-loss-to-continuum cusps: An algebraic approach

    International Nuclear Information System (INIS)

    An algebraic approach for evaluation of the bound-free transition form factor -Vertical Barexp(iQxr)Vertical Barn,l,m> between arbitrary hydrogenic initial states Vertical Barn,l,m> and continuum final states Vertical Barv -> in the low-velocity limit v<< Z/n is developed. This form factor determines the initial-state dependence of the electron-loss-to-continuum (ELC) cusp in the Born approximation. The method extends the well-known algebraic O(4,2) approach for bound-bound transitions to low-lying continuum states by exploiting the continuity across the ionization limit. A correspondence between scattering states and Rydberg bound states is established using the fact that the Runge-Lenz vector A and the velocity vector v become collinear near the ionization threshold. The present method takes explicitly into account the dynamical symmetry of the Coulomb field. We use the result for a systematic investigation of the doubly differential cross section and the shape of ELC cusps as a function of the initial state, its binding energy, the target, and the projectile velocity (v/sub P/) within the Born approximation. Comparison is made with recent experimental data from our laboratory for highly charged projectiles. We find qualitative: and sometimes quantitative: agreement with the data

  1. LS1 Report: A brand new set-up for ASACUSA-CUSP

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    ASACUSA is running for the first time with a totally new set-up. Three new vital instruments have been designed, produced and installed during LS1 in addition to several other major modifications. The collaboration is now ready to perform the first high-precision measurement of the hyperfine structure of antihydrogen – a study that aims at comparing the inner properties of matter and antimatter.   The ASACUSA set-up. The ASACUSA-CUSP collaboration comprises about 30 scientists from various institutes in Europe and Japan. Because of the Japanese contribution, the experiment is often known by its Japanese pronunciation, the experiment’s logo is in Japanese, and the logbook uses Japanese time! This year, for the first time, the experiment is running with a completely new set-up, which now includes a new superconducting double cusp magnet, a new tracking detector and a new final antihydrogen detector. “The magnet is the heart of the ASACUSA experiment,” expl...

  2. Transcatheter aortic valve implantation today and tomorrow.

    Science.gov (United States)

    Wenaweser, Peter; Praz, Fabien; Stortecky, Stefan

    2016-01-01

    Aortic stenosis is the most common valvular heart disease in Western industrial countries (including Switzerland) with a prevalence of about 5% in the population aged 75 and over. If left untreated, symptomatic patients have a rate of death of more than 50% within 2 years. As a result of age and elevated surgical risk, an important proportion of elderly patients are not referred to surgery. Thus, the introduction of transcatheter aortic valve implantation (TAVI) in 2002 has initiated a paradigm shift in the treatment of patients with symptomatic, severe aortic stenosis. The early technical and procedural success of this minimal invasive treatment in high-risk patients has promoted further innovation and development of transcatheter heart valve (THV) systems during the last 13 years. Downsizing of the delivery catheters along with technical improvements aiming to reduce postprocedural paravalvular regurgitation have resulted in a significant reduction in mortality. As a consequence, TAVI is nowadays established as safe and effective treatment for selected inoperable and high-risk patients. Ongoing studies are investigating the outcome of intermediate risk patients allocated to either surgical aortic valve replacement (SAVR) or TAVI. Despite these advancements, some specific areas of concern still require attention and need further investigations including conduction disturbances, valve degeneration and antithrombotic management. Although the off-label use of TAVI devices in the mitral, tricuspid or pulmonary position has recently developed, important limitations still apply and careful patient selection remains crucial. This review aims to summarise the available clinical evidence of transcatheter aortic valve treatment during the last 13 years and to provide a glimpse of future technologies. PMID:26999727

  3. Coronary Ostial Stenosis after Aortic Valve Replacement

    Science.gov (United States)

    Ziakas, Antonios G.; Economou, Fotios I.; Charokopos, Nicholas A.; Pitsis, Antonios A.; Parharidou, Despina G.; Papadopoulos, Thomas I.; Parharidis, Georgios E.

    2010-01-01

    Coronary ostial stenosis is a rare but potentially serious sequela after aortic valve replacement. It occurs in the left main or right coronary artery after 1% to 5% of aortic valve replacement procedures. The clinical symptoms are usually severe and may appear from 1 to 6 months postoperatively. Although the typical treatment is coronary artery bypass grafting, patients have been successfully treated by means of percutaneous coronary intervention. Herein, we present the cases of 2 patients in whom coronary ostial stenosis developed after aortic valve replacement. In the 1st case, a 72-year-old man underwent aortic valve replacement and bypass grafting of the saphenous vein to the left anterior descending coronary artery. Six months later, he experienced a non-ST-segment-elevation myocardial infarction. Coronary angiography revealed a critical stenosis of the right coronary artery ostium. In the 2nd case, a 78-year-old woman underwent aortic valve replacement and grafting of the saphenous vein to an occluded right coronary artery. Four months later, she experienced unstable angina. Coronary angiography showed a critical left main coronary artery ostial stenosis and occlusion of the right coronary artery venous graft. In each patient, we performed percutaneous coronary intervention and deployed a drug-eluting stent. Both patients were asymptomatic on 6-to 12-month follow-up. We attribute the coronary ostial stenosis to the selective ostial administration of cardioplegic solution during surgery. We conclude that retrograde administration of cardioplegic solution through the coronary sinus may reduce the incidence of postoperative coronary ostial stenosis, and that stenting may be an efficient treatment option. PMID:20844624

  4. Correlative magnetic resonance imaging in the evaluation of aortic and pulmonary artery abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Risius, B.; O' Donnell, J.K.; Geisinger, M.A.; Zelch, M.G.; George, C.R.; Graor, R.A.; Moodie, D.S.

    1985-05-01

    Magnetic resonance imaging (MRI) yields excellent quality images of the cardiovascular system utilizing the inherent natural contrast between flowing blood and the surrounding anatomic structures. To evaluate the clinical usefulness of MRI in the noninvasive diagnosis of large vessel disorders, the authors have performed MRI on 40 pts with either aortic or pulmonary artery abnormalities (18 thoracic or abdominal aortic aneurysms, 8 aorto-occlusive disease, 6 dissecting aneurysms, 4 Marfan's syndrome, 2 pulmonary artery aneurysms 1 pulmonary artery occlusion, 1 aortic coarctation). Images were obtained in the transverse, coronal and sagital body planes utilizing a 0.6T superconductive magnet. Cardiac and/or respiratory gating was employed in most cases. Correlation was made for all studies with conventional or digital subtraction angiography, computed tomography, and/or ultrasound. The diagnostic information obtained by MRI equaled or exceeded that obtained by other imaging techniques except for the few cases where cardiac arrhythmias precluded adequate gated acquisition. All aneurysms and their relationships to adjacent structures were readily demonstrated as were the presence or absence of mural thrombi and dissecting intimal flaps. Angiographically demonstrated atherosclerotic plaques and luminal stenoses were seen by MRI in all patients without arrhythmias. The authors concluded that MRI is a powerful noninvasive diagnostic aid in the delineation of large vessel disorders, especially where knowledge of anatomic interrelationships can guide surgical or other interventional planning.

  5. Fluid dynamics of aortic root dilation in Marfan syndrome

    CERN Document Server

    Querzoli, Giorgio; Espa, Stefania; Costantini, Martina; Sorgini, Francesca

    2014-01-01

    Aortic root dilation and propensity to dissection are typical manifestations of the Marfan Syndrome (MS), a genetic defect leading to the degeneration of the elastic fibres. Dilation affects the structure of the flow and, in turn, altered flow may play a role in vessel dilation, generation of aneurysms, and dissection. The aim of the present work is the investigation in-vitro of the fluid dynamic modifications occurring as a consequence of the morphological changes typically induced in the aortic root by MS. A mock-loop reproducing the left ventricle outflow tract and the aortic root was used to measure time resolved velocity maps on a longitudinal symmetry plane of the aortic root. Two dilated model aortas, designed to resemble morphological characteristics typically observed in MS patients, have been compared to a reference, healthy geometry. The aortic model was designed to quantitatively reproduce the change of aortic distensibility caused by MS. Results demonstrate that vorticity released from the valve ...

  6. [Use of sutureless prosthetic aortic valves in cardiac surgery].

    Science.gov (United States)

    Santarpino, Giuseppe; Fischlein, Theodor

    2014-03-01

    In the last years, an increasing proportion of high-risk patients undergo surgical aortic valve replacement. In order to reduce the risk associated with cross-clamp time or cardioplegic ischemic time, sutureless aortic prostheses have been developed. These bioprosthetic valves are not hand sewn, and this technological advance translates into reduced implantation times, thus improving outcome of patients referred for aortic valve replacement. At present, three sutureless bioprostheses are available on the market: 3f Enable (Medtronic Inc., Minneapolis, Minnesota, USA), Perceval (Sorin Group, Saluggia, Italy) and Intuity (Edwards Lifesciences, Irvine, California, USA). This article provides an overview of the available literature on sutureless aortic valves with the aim to better define current role and future perspectives of sutureless aortic bioprostheses for the treatment of aortic valve stenosis. PMID:24770430

  7. Diagnosis of aortic aneurysms by scintigraphy and ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Caille, G. (Centre Hospitalier, Saint-Nazaire (France)); Chatal, J.F.; Tellier, J.L.; Talmant, C.; Guihard, R. (Centre Rene-Gauducheau, 44 - Nantes (France))

    1981-10-01

    Angioscintigraphy, performed on 50 patients suspected of aortic aneurysm and complemented by abdominal ultrasonography in 31 cases, disclosed: - Three cases of thoracic aortic aneurysm, 2 of which were confirmed by arteriography and surgery. It was impossible to perform surgery in the third case, no arteriography was done. Strict agreement with standard thoracic images had made the angioscintigraphic diagnosis seem correct. Twenty-seven cases of abdominal aortic aneurysms were confirmed by arteriography or surgery. Ultrasonography disclosed an abdominal aortic aneurysm in 26 cases, 20 of which were confirmed. The agreement of the two procedures in 10 unconfirmed cases led us to consider the diagnosis as correct. Angioscintigraphy appears to be a reliable procedure for detecting thoracic and abdominal aortic aneurysms. Ultrasonography is the simplest and least costly procedure for study of abdominal aortic aneurysms.

  8. Diagnosis of aortic aneurysms by scintigraphy and ultrasonography

    International Nuclear Information System (INIS)

    Angioscintigraphy, performed on 50 patients suspected of aortic aneurysm and complemented by abdominal ultrasonography in 31 cases, disclosed: - Three cases of thoracic aortic aneurysm, 2 of which were confirmed by arteriography and surgery. It was impossible to perform surgery in the third case, no arteriography was done. Strict agreement with standard thoracic images had made the angioscintigraphic diagnosis seems correct. - Twenty-seven cases of abdominal aortic aneurysms confirmed by arteriography or surgery. Ultrasonography disclosed an abdominal aortic aneurysm in 26 cases, 20 of which were confirmed. The agreement of the two procedures in 10 unconfirmed cases led us to consider the diagnosis as correct. Angioscintigraphy appears to be a reliable procedure for detecting thoracic and abdominal aortic aneurysms. Ultrasonography is the simplest and least costly procedure for study of abdominal aortic aneurysms

  9. Cusp-latitude Pc3 spectra: band-limited and power-law components

    Directory of Open Access Journals (Sweden)

    P. V. Ponomarenko

    Full Text Available This work attempts to fill a gap in comparative studies of upstream-generated Pc3–4 waves and broad band ULF noise observed at cusp latitudes. We performed a statistical analysis of the spectral properties of three years of cusp-latitude ground magnetometer data, finding that the average daytime Pc3–4 spectra are characterized by two principal components: an upstream-related band-limited enhancement (‘signal’ and a power-law background (‘noise’ with S(f a  f -4 . Based on this information we developed an algorithm allowing for the deconvolution of these two components in the spectral domain. The frequency of the signal enhancement increases linearly with IMF magnitude as f [mHz] ~ 4.4 | BIMF | [nT], and its power maximizes around IMF cone angles qxB ~ 20 and 160° and at 10:30–11:00 MLT. Both spectral components exhibit similar semiannual variations with equinoctial maxima. The back-ground noise power grows with increasing southward Bz and remains nearly constant for northward Bz . Its diurnal variation resembles that of Pc5 field-line resonance power, with a maximum near 09:00 MLT. Both the band-limited signal and broad band noise components show power-law growth with solar wind velocity a V 5.71sw and a V 4.12sw, respectively. Thus, the effective signal-to-noise ratio increases with in-creasing Vsw. The observations suggest that the noise generation is associated with reconnection processes.

    Key words. Magnetospheric physics (magnetopause, cusp, and boundary layers; MHD waves and instabilities; solar wind magnetosphere interactions

  10. Ionospheric cusp flows pulsed by solar wind Alfvén waves

    Directory of Open Access Journals (Sweden)

    P. Prikryl

    Full Text Available Pulsed ionospheric flows (PIFs in the cusp foot-print have been observed by the SuperDARN radars with periods between a few minutes and several tens of minutes. PIFs are believed to be a consequence of the interplanetary magnetic field (IMF reconnection with the magnetospheric magnetic field on the dayside magnetopause, ionospheric signatures of flux transfer events (FTEs. The quasiperiodic PIFs are correlated with Alfvénic fluctuations observed in the upstream solar wind. It is concluded that on these occasions, the FTEs were driven by Alfvén waves coupling to the day-side magnetosphere. Case studies are presented in which the dawn-dusk component of the Alfvén wave electric field modulates the reconnection rate as evidenced by the radar observations of the ionospheric cusp flows. The arrival of the IMF southward turning at the magnetopause is determined from multipoint solar wind magnetic field and/or plasma measurements, assuming plane phase fronts in solar wind. The cross-correlation lag between the solar wind data and ground magnetograms that were obtained near the cusp footprint exceeded the estimated spacecraft-to-magnetopause propagation time by up to several minutes. The difference can account for and/or exceeds the Alfvén propagation time between the magnetopause and ionosphere. For the case of short period ( < 13 min PIFs, the onset times of the flow transients appear to be further delayed by at most a few more minutes after the IMF southward turning arrived at the magnetopause. For the case of long period (30 – 40 min PIFs, the observed additional delays were 10–20 min. We interpret the excess delay in terms of an intrinsic time scale for reconnection (Russell et al., 1997 which can be explained by the surface-wave induced magnetic reconnection mechanism (Uberoi et al., 1999. Here, surface waves with wavelengths larger than the thickness of the neutral layer induce a tearing-mode instability whose rise time explains the

  11. Design and fabrication of a large magnetic cusp type of plasma generator for the production of negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Biagi, L.A.; Ehlers, K.W.; Leung, K.N.; Matuk, C.A.; Moon, S.D.; Paterson, J.A.

    1981-10-01

    The design and fabrication techniques for a large magnetic bucket type of plasma source designed for the production of negative ions by surface conversion are described. These include the design of a converter structure, cesium oven and injector, variable aperture electrode, accelerator section as well as the features of the magnetic cusp geometry employed.

  12. Efficient Word Reading: Automaticity of Print-Related Skills Indexed by Rapid Automatized Naming through Cusp-Catastrophe Modeling

    Science.gov (United States)

    Sideridis, Georgios D.; Simos, Panagiotis; Mouzaki, Angeliki; Stamovlasis, Dimitrios

    2016-01-01

    The study explored the moderating role of rapid automatized naming (RAN) in reading achievement through a cusp-catastrophe model grounded on nonlinear dynamic systems theory. Data were obtained from a community sample of 496 second through fourth graders who were followed longitudinally over 2 years and split into 2 random subsamples (validation…

  13. Design and fabrication of a large magnetic cusp type of plasma generator for the production of negative ions

    International Nuclear Information System (INIS)

    The design and fabrication techniques for a large magnetic bucket type of plasma source designed for the production of negative ions by surface conversion are described. These include the design of a converter structure, cesium oven and injector, variable aperture electrode, accelerator section as well as the features of the magnetic cusp geometry employed

  14. Letter to the EditorA statistical study of the location and motion of the HF radar cusp

    Directory of Open Access Journals (Sweden)

    K. A. McWilliams

    Full Text Available The large-scale and continuous monitoring of the ionospheric cusp region offered by HF radars has been exploited in order to examine the statistical location and motion of the equatorward edge of the HF radar cusp as a function of the upstream IMF BZ component. Although a considerable scatter is seen, both parameters have a clear influence from the north-south component of the IMF. Excellent agreement is achieved with previous observations from low altitude spacecraft data. The HF radar cusp region is seen to migrate equatorward at a rate of 0.02° min-1 nT-1 under IMF BZ south conditions, but remains static for IMF BZ north. The motion of the cusp implies an addition of magnetic flux of ~ 2 × 104 Wbs-1 nT-1 under IMF BZ south conditions, equivalent to a reconnection voltage of 20 kV nT-1, which is consistent with previous estimates from case studies on both the dayside and nightside regions.Key words. Ionosphere (auroral ionosphere – Magnetospheric physics (magnetosphere-ionosphere interaction; solar wind magnetosphere interactions

  15. Electron-electron cusp condition and asymptotic behavior for the Pauli potential in pair density functional theory.

    Science.gov (United States)

    Nagy, A; Amovilli, C

    2008-03-21

    In the ground state, the pair density n can be determined by solving a single auxiliary equation of a two-particle problem. Electron-electron cusp condition and asymptotic behavior for the Pauli potential of the effective potential of the two-particle equation are presented. PMID:18361562

  16. Cusp deflection, infraction and fracture in endodontically treated teeth filled with three temporary filling materials (in vitro

    Directory of Open Access Journals (Sweden)

    Ali Eskandarizade

    2015-12-01

    Full Text Available Aim: the aim of this study was to compare cusp deflection, infraction and fracture in teeth filled with three temporary filling materials. Materials & method: Forty five extracted human premolar teeth were chosen. After root canal therapy and mesio-occluso-distal cavity preparation, samples were randomly divided into three groups , each contained 15 teeth and filled with three temporary filling materials: Cavisol (Golchai-Iran, Coltosol F (Coltene,Swiss and Coltene (Ariadent,Iran. Teeth were kept in normal saline at room temperature and every day the intercuspal distance was measured under stereomicroscope for 20 days. Infractions as well as fractures were also noted. Data were analyzed in SPSS 17 using Repeated measurement ANOVA test to evaluate the intercuspal distance and expansion of each sample every day. Results: Intercuspal distance increased in all three groups but was significantly more in Coltosol F group. On the days 10 and 16 two teeth filled with Coltosol F had cusp fracture. Conclusion: Temporary filling materials have hygroscopic expansion and cause cusp deflection which may lead to cusp fracture, so it is recommended to use them in short period of time.

  17. Recent developments for surgical aortic valve replacement: the concept of sutureless valve technology

    OpenAIRE

    Carrel, Thierry; Englberger, Lars; Stalder, Mario

    2013-01-01

    Aortic stenosis has become the most frequent type of valvular heart disease in Europe and North America and presents in the large majority of patients as calcified aortic stenosis in adults of advanced age. Surgical aortic valve replacement has been recognized to be the definitive therapy which improves considerably survival for severe aortic stenosis since more than 40 years. In the most recent period, operative mortality of isolated aortic valve replacement for aortic stenosis varies betwee...

  18. Aortic incompetence in HLA B27-positive juvenile arthritis.

    OpenAIRE

    Kean, W F; Anastassiades, T. P.; Ford, P M

    1980-01-01

    The early onset of isolated aortic incompetence in a male child with HLA B27 and peripheral arthritis is reported. Acute anterior uveitis and lone aortic incompetence occurred at 1 and 9 months respectively after the development of the acute inflammatory arthritis. The uveitis resolved with local therapy and the arthritis remitted 10 months after the onset. There has been no recurrence of the arthritis after 10 years of close follow-up but the aortic incompetence has persisted, though it rema...

  19. Use of omental pedicles in mycotic abdominal aortic aneurysm repair

    OpenAIRE

    Alibhai, M.K.; Samee, A; Ahmed, M.; Duffield, R.

    2011-01-01

    We report a case of a sixty year old man with a mycotic infra-renal abdominal aortic aneurysm complicated by a left psoas abscess. After treatment with parenteral antibiotics he underwent early aortic reconstruction with an in-situ prosthetic graft wrapped in an omental pedicle. Mycotic abdominal aortic aneurysms can be treated in this way despite the potential for graft infection from persisting retroperitoneal sepsis.

  20. DEGENERATIVE AORTIC STENOSIS: PATHOGENESIS AND NEW PRINCIPLES OF TREATMENT

    OpenAIRE

    O. V. Andropova; V. N. Anokhin

    2016-01-01

    Aim. To reveal of markers of inflammation and progression of calcification in patients with degenerative aortic stenosis (DAS). Material and methods. A single-stage study was done in 85 patients with degenerative calcification of aortic valve (42 patients with DAS and 43 patients without DAS). The techniques for assessing the severity of aortic valve calcification included ultrasonic diagnostics and multislice spiral computed tomography. Markers of inflammation and lipid profile were investig...

  1. Temporal trends in the incidence and prognosis of aortic stenosis

    DEFF Research Database (Denmark)

    Martinsson, Andreas; Li, Xinjun; Andersson, Charlotte;

    2015-01-01

    BACKGROUND: The aging of Western populations is expected to result in increasing occurrence of aortic stenosis (AS), but data are limited. Recent studies have reported declining incidence and mortality for other major heart diseases. We aimed to study temporal trends in the incidence and prognosis...... could suggest that improved risk factor control and cardiovascular therapy, combined with increased use of aortic valve replacement in the elderly and reduced perioperative mortality in aortic valve replacement, have translated into favorable effects for AS....

  2. Transcatheter aortic valve prosthesis surgically replaced 4 months after implantation

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav; Lund, Jens Teglgaard; Engstrøm, Thomas;

    2010-01-01

    Transcatheter aortic valve implantation is a new and rapidly evolving treatment option for high-risk surgical patients with degenerative aortic valve stenosis. Long-term results with these new valve prostheses are lacking, and potential valve dysfunction and failure would require valve replacemen....... We report the first case of surgical valve replacement in a patient with a dysfunctional transcatheter-implanted aortic valve prosthesis 4 months after implantation....

  3. Giant aortic arch aneurysm complicating Kawasaki′s disease

    OpenAIRE

    Kaouthar Hakim; Rafik Boussada; Lilia Chaker; Fatma Ouarda

    2014-01-01

    Kawasaki disease (KD) is a common acute vasculitis in pediatric population that usually involves small- and middle-sized arteries, commonly coronary arteries. Although the incidence and natural course of coronary aneurysms after KD are well documented in studies, related reports on peripheral arterial and aortic aneurysms are scarce. We report the occurrence of a giant aortic aneurysm involving the horizontal part of aortic arch in a 28-month-old boy diagnosed with KD. This complication was m...

  4. Aortic stiffness: pathophysiology, clinical implications, and approach to treatment

    OpenAIRE

    Sethi S; Rivera O.; Oliveros R; Chilton R

    2014-01-01

    Salil Sethi, Oscar Rivera, Rene Oliveros, Robert Chilton University of Texas Health Science Center, San Antonio, TX, USA Abstract: Aortic stiffness is a hallmark of aging, and classic cardiovascular risk factors play a role in accelerating this process. Current changes in medicine, which focus on preventive care, have led to a growing interest in noninvasive evaluation of aortic stiffness. Aortic stiffness has emerged as a good tool for further risk stratification because it has been linked ...

  5. Aortic root dynamics and surgery: from craft to science

    OpenAIRE

    Cheng, Allen; Dagum, Paul; Miller, D. Craig

    2007-01-01

    Since the fifteenth century beginning with Leonardo da Vinci's studies, the precise structure and functional dynamics of the aortic root throughout the cardiac cycle continues to elude investigators. The last five decades of experimental work have contributed substantially to our current understanding of aortic root dynamics. In this article, we review and summarize the relevant structural analyses, using radiopaque markers and sonomicrometric crystals, concerning aortic root three-dimensiona...

  6. Tubercular mycotic aortic aneurysm: A case report

    Directory of Open Access Journals (Sweden)

    Satish Kumar

    2016-01-01

    Full Text Available Tubercular aneurysms of larger vessels, particularly the aorta is very rare. The first case of tubercular involvement of the aorta in the form of aortitis was reported in 1882 by Weigert and the first case of tubercular mycotic aneurysm of the aorta was reported in 1895. The preoperative diagnosis of tubercular aortic aneurysm is difficult. Even at surgery, determining the tubercular nature of the lesion is problematic. The gross appearance may not be distinctive, and acid-fast stains are unlikely to be performed. We report the case of a young female patient who was started on antitubercular treatment for pleural effusion and was found to have aortic aneurysm, which later on proved to be tubercular in origin.

  7. Spontaneous aortic dissecting hematoma in two dogs.

    Science.gov (United States)

    Boulineau, Theresa Marie; Andrews-Jones, Lydia; Van Alstine, William

    2005-09-01

    This report describes 2 cases of spontaneous aortic dissecting hematoma in young Border Collie and Border Collie crossbred dogs. Histology was performed in one of the cases involving an unusual splitting of the elastin present within the wall of the aorta, consistent with elastin dysplasia as described in Marfan syndrome in humans. The first case involved a young purebred Border Collie that died suddenly and the second case involved a Border Collie crossbred dog that died after a 1-month history of seizures. Gross lesions included pericardial tamponade with dissection of the ascending aorta in the former case and thoracic cavity hemorrhage, mediastinal hematoma, and aortic dissection in the latter. Histologic lesions in the case of the Border Collie crossbred dog included a dissecting hematoma of the ascending aorta with elastin dysplasia and right axillary arterial intimal proliferation. PMID:16312247

  8. Acute aortic dissection caused by Clostridium septicum aortitis.

    Science.gov (United States)

    Eplinius, Franziska; Hädrich, Carsten

    2014-11-01

    Clostridium septicum aortitis is a rare cause of aortic dissection. So far, only 28 cases have been described in literature before. Most of these cases occurred in elderly patients and an association to colonic neoplasms and/or atherosclerosis has been witnessed frequently. Here we report the case of a 32-year-old man with fatal aortic dissection due to aortic infection with C. septicum. Beside a case of a 22-year-old man who died of aortic dissection due to C. septicum aortitis this is the second case of C. septicum aortitis in a young individual with no signs of colonic neoplasms or atherosclerosis. PMID:25242573

  9. FOXE3 mutations predispose to thoracic aortic aneurysms and dissections

    Science.gov (United States)

    Kuang, Shao-Qing; Medina-Martinez, Olga; Guo, Dong-chuan; Gong, Limin; Regalado, Ellen S.; Reynolds, Corey L.; Boileau, Catherine; Jondeau, Guillaume; Prakash, Siddharth K.; Kwartler, Callie S.; Zhu, Lawrence Yang; Peters, Andrew M.; Duan, Xue-Yan; Bamshad, Michael J.; Shendure, Jay; Nickerson, Debbie A.; Santos-Cortez, Regie L.; Dong, Xiurong; Leal, Suzanne M.; Majesky, Mark W.; Swindell, Eric C.; Jamrich, Milan; Milewicz, Dianna M.

    2016-01-01

    The ascending thoracic aorta is designed to withstand biomechanical forces from pulsatile blood. Thoracic aortic aneurysms and acute aortic dissections (TAADs) occur as a result of genetically triggered defects in aortic structure and a dysfunctional response to these forces. Here, we describe mutations in the forkhead transcription factor FOXE3 that predispose mutation-bearing individuals to TAAD. We performed exome sequencing of a large family with multiple members with TAADs and identified a rare variant in FOXE3 with an altered amino acid in the DNA-binding domain (p.Asp153His) that segregated with disease in this family. Additional pathogenic FOXE3 variants were identified in unrelated TAAD families. In mice, Foxe3 deficiency reduced smooth muscle cell (SMC) density and impaired SMC differentiation in the ascending aorta. Foxe3 expression was induced in aortic SMCs after transverse aortic constriction, and Foxe3 deficiency increased SMC apoptosis and ascending aortic rupture with increased aortic pressure. These phenotypes were rescued by inhibiting p53 activity, either by administration of a p53 inhibitor (pifithrin-α), or by crossing Foxe3–/– mice with p53–/– mice. Our data demonstrate that FOXE3 mutations lead to a reduced number of aortic SMCs during development and increased SMC apoptosis in the ascending aorta in response to increased biomechanical forces, thus defining an additional molecular pathway that leads to familial thoracic aortic disease. PMID:26854927

  10. Aortic Disease in the Young: Genetic Aneurysm Syndromes, Connective Tissue Disorders, and Familial Aortic Aneurysms and Dissections

    Directory of Open Access Journals (Sweden)

    Marcelo Cury

    2013-01-01

    Full Text Available There are many genetic syndromes associated with the aortic aneurysmal disease which include Marfan syndrome (MFS, Ehlers-Danlos syndrome (EDS, Loeys-Dietz syndrome (LDS, familial thoracic aortic aneurysms and dissections (TAAD, bicuspid aortic valve disease (BAV, and autosomal dominant polycystic kidney disease (ADPKD. In the absence of familial history and other clinical findings, the proportion of thoracic and abdominal aortic aneurysms and dissections resulting from a genetic predisposition is still unknown. In this study, we propose the review of the current genetic knowledge in the aortic disease, observing, in the results that the causative genes and molecular pathways involved in the pathophysiology of aortic aneurysm disease remain undiscovered and continue to be an area of intensive research.

  11. Animal Models of Calcific Aortic Valve Disease

    OpenAIRE

    Sider, Krista L.; Blaser, Mark C.; Simmons, Craig A.

    2011-01-01

    Calcific aortic valve disease (CAVD), once thought to be a degenerative disease, is now recognized to be an active pathobiological process, with chronic inflammation emerging as a predominant, and possibly driving, factor. However, many details of the pathobiological mechanisms of CAVD remain to be described, and new approaches to treat CAVD need to be identified. Animal models are emerging as vital tools to this end, facilitated by the advent of new models and improved understanding of the u...

  12. Diagnostic imaging of abdominal aortic aneurysms

    International Nuclear Information System (INIS)

    The survey explains the available methods for diagnostic imaging of aortic aneurysms, i.e. the conventional methods of ultrasonography and intra-arterial angiography as well as the modern tomographic and image processing techniques such as CT, DSA, and MRT. The various methods are briefly discussed with respect to their sensitivity and specificity. The authors expect that MRI will become the modality of choice, due to absence of radiation exposure of the patients

  13. The vanishing giant abdominal aortic aneurysm.

    Science.gov (United States)

    Krivoshei, Lian; Halak, Moshe; Schneiderman, Jacob; Silverberg, Daniel

    2011-05-01

    Spontaneous sac size regression of a giant abdominal aortic aneurysm (AAA) is a rare event that has not been previously described. We report a case of an 89-year-old woman with a known 9-cm AAA, which was diagnosed in 2003. The patient had refused any kind of treatment at that time. Recent imaging studies obtained 7 years later revealed an AAA of 4 cm diameter. This is the first recorded case of significant spontaneous AAA sac shrinkage. PMID:21444348

  14. Neuropsychiatric symptoms in patients with aortic aneurysms.

    Directory of Open Access Journals (Sweden)

    Bernhard T Baune

    Full Text Available BACKGROUND: Emerging evidence suggests that vascular disease confers vulnerability to a late-onset of depressive illness and the impairment of specific cognitive functions, most notably in the domains of memory storage and retrieval. Lower limb athero-thrombosis and abdominal aortic aneurysm (AAA have both been previously associated with neuropsychiatric symptoms possibly due to associated intracerebral vascular disease or systemic inflammation, hence suggesting that these illnesses may be regarded as models to investigate the vascular genesis of neuropsychiatric symptoms. The aim of this study was to compare neuropsychiatric symptoms such as depression, anxiety and a variety of cognitive domains in patients who had symptoms of peripheral athero-thrombosis (intermittent claudication and those who had an asymptomatic abdominal aortic aneurysm AAA. METHODOLOGY/PRINCIPAL FINDINGS: In a cross-sectional study, 26 participants with either intermittent claudication or AAA were assessed using a detailed neuropsychiatric assessment battery for various cognitive domains and depression and anxiety symptoms (Hamilton Depression and Anxiety Scales. Student t test and linear regression analyses were applied to compare neuropsychiatric symptoms between patient groups. AAA participants showed greater levels of cognitive impairment in the domains of immediate and delayed memory as compared to patients who had intermittent claudication. Cognitive dysfunction was best predicted by increasing aortic diameter. CRP was positively related to AAA diameter, but not to cognitive function. AAA and aortic diameter in particular were associated with cognitive dysfunction in this study. CONCLUSIONS/SIGNIFICANCE: AAA patients are at a higher risk for cognitive impairment than intermittent claudication patients. Validation of this finding is required in a larger study, but if confirmed could suggest that systemic factors peculiar to AAA may impact on cognitive function.

  15. Incidence of patients with acute aortic dissection

    OpenAIRE

    Salkovski, Safet; Panova, Gordana; Velickova, Nevenka; Panova, Blagica; Panov, Nenad; Nikolovska, Lence; Dzidrova, Violeta

    2012-01-01

    Introduction: Acute aortic dissection (AAD) e life-threatening condition that characterizes the high mortality worldwide (7-8%). When AAD is split in the wall of the aorta where the blood circulates between layers of the wall which can lead to its rupture. Early recognition of symptoms and appropriate response to the medical team is crucial to the outcome of the patient. On receipt of a patient with chest pain to bear in mind the possibility of AAD. Standard diagnostics when fasti...

  16. Prevalence of the Talon Cusp at the Lateral Incisors of Two Individuals of Greek Origin - A Case Study

    Directory of Open Access Journals (Sweden)

    Theodoros Pitsios

    2010-01-01

    Full Text Available Background: Dental morphological traits are useful for providing information for phylogenic and genetic studies within and among species and populations. Studies of dental traits in the very interesting geographic area of Greece can provide important data on the genetic constitution and the profile of the dental traits of this particular geographic population. Talon cusp is a rare dental trait in deciduous and permanent dentition and is expressed in several degrees and different frequencies between humans, thus being useful in comparing populations.Aims: The aim of the present study is to detect the presence and degree of expression of the morphological trait of the Talon cusp in a demographic group of adult individuals of Greek origin residing in Athens.Methodology: The data were collected by examination of a demographic group of 113 adult individuals of Greek origin residing in Athens.Results: The age range of individuals belonging to this demographic group was from 12 to 71 years (i.e. 37 ±5 years mean age. Of these individuals, 55 were women and 58 men. The examination focussing on the presence or absence of Talon cusp was carried out according to the system developed and suggested by Hattab et al. (1996. Following the examination the 113 individuals, two cases of Talon cusp were recorded (i.e. a frequency of 2.6%. In both cases, the tooth displaying the trait was the lateral incisor of the maxilla. In the first case, the Talon cusp was located on the lateral incisor of the right maxilla. The degree of expression was 2 and its shape was a V, according to the Hattab et al.(1996 scoring system. In the second case, the Talon trait was located on the lateral incisor of the left maxilla. The degree of expression was 2 and its shape a V, again according to the Hattab et al. (1996 scoring system.

  17. Design, fabrication and test of double cusp fusion machine, RFC-XX

    International Nuclear Information System (INIS)

    Description is made about the design, fabrication and test results of the world's largest double cusp fusion machine called Radio Frequency Containment-Type Twenty (RFC-XX). RFC-XX was planned by the Insitute of Plasma Physics, Nagoya University. The main parts (the magnetic field coil system, the vacuum vessel, the plasma source, etc.) were completed by Toshiba in march 1977. For the design and manufacture, many difficult problems including the realization of high-precision magnetic field and ultrahigh vacuum, maintaining excellent accessibility to the machine for plasma experiments have been solved. The results of tests after fabrication have shown that the requirements of plasma experiment facilities are fully satisfied. (author)

  18. BPS-saturated string amplitudes: K3 elliptic genus and Igusa cusp form χ10

    International Nuclear Information System (INIS)

    We study BPS-saturated one-loop amplitudes in type II string theory compactified on K3×T2. The classes of amplitudes we consider are only sensitive to the very basic topological data of the internal K3 manifold. As a consequence, the integrands of the former are related to the elliptic genus of K3, which can be decomposed into representations of the internal N=4 superconformal algebra. Depending on the precise choice of external states these amplitudes capture either only the contribution of the short multiplets or the full series including intermediate multiplets. In the latter case we can define a generating functional for the whole class, which we show is given by the weight ten Igusa cusp form χ10 of Sp(4,Z). We speculate on possible algebraic implications of our result on the BPS states of the N=4 type II compactification.

  19. Structure of Dark Matter Halos From Hierarchical Clustering. III. Shallowing of The Inner Cusp

    CERN Document Server

    Fukushige, T; Makino, J; Fukushige, Toshiyuki; Kawai, Atsushi; Makino, Junichiro

    2004-01-01

    We investigate the structure of the dark matter halo formed in the cold dark matter scenarios by N-body simulations with parallel treecode on GRAPE cluster systems. We simulated 8 halos with the mass of $4.4\\times 10^{14}M_{\\odot}$ to $1.6\\times 10^{15}M_{\\odot}$ in the SCDM and LCDM model using up to 30 million particles. With the resolution of our simulations, the density profile is reliable down to 0.2 percent of the virial radius. Our results show that the slope of inner cusp within 1 percent virial radius is shallower than -1.5, and the radius where the shallowing starts exhibits run-to-run variation, which means the innermost profile is not universal.

  20. Countering the stray magnetic field of the CUSP trap by using additional coils

    CERN Document Server

    Thole, Jelle

    2016-01-01

    The ASACUSA experiment at the Antiproton Decelerator (AD) at CERN tries to measure the Hyperfine Structure (HFS) of Antihydrogen (H ̄) using a Rabi spectroscopy set-up. In measuring this HFS it will yield a very precise test of CPT-symmetry. For this set-up to work a homogeneous magnetic field is needed in the cavity where the Hyperfine transition of H ̄ occurs. Due to the stray fields from the CUSP trap, where H ̄ is produced, additional coils are needed to counter these fields. It is found, using COMSOL simulations, that two coils are suitable for this. Leading to a relative standard deviation of the magnetic field of σB/B = 1.06%.