Correction of aortic insufficiency with an external adjustable prosthetic aortic ring.

Science.gov (United States)

Gogbashian, Andrew; Ghanta, Ravi K; Umakanthan, Ramanan; Rangaraj, Aravind T; Laurence, Rita G; Fox, John A; Cohn, Lawrence H; Chen, Frederick Y

2007-09-01

Less invasive, valve-sparing options are needed for patients with aortic insufficiency (AI). We sought to evaluate the feasibility of reducing AI with an external adjustable aortic ring in an ovine model. To create AI, five sheep underwent patch plasty enlargement of the aortic annulus and root by placement of a 10 x 15 mm pericardial patch between the right and noncoronary cusps. An adjustable external ring composed of a nylon band was fabricated and placed around the aortic root. Aortic flow, aortic pressure, and left ventricular pressures were measured with the ring loose (off) and tightened (on). Mean regurgitant orifice area decreased by 86%, from 0.07 +/- 0.03 cm2 (ring loose, off) to 0.01 +/- 0.00 cm2 (ring tightened, on) [p < 0.01]. The regurgitant fraction decreased from 18 +/- 4% to 2 +/- 1% [p < 0.01]. The ring did not significantly affect stroke volume and aortic pressure. An ovine model of aortic root dilatation resulting in acute AI has been developed. In this model, application of an external, adjustable constricting aortic ring eliminated AI. An aortic ring may be a useful adjunct in reducing AI secondary to annular dilatation.

Reimplantation valve-sparing aortic root replacement with the Valsalva graft: what have we learnt after 100 cases?

Science.gov (United States)

Settepani, Fabrizio; Bergonzini, Marcello; Barbone, Alessandro; Citterio, Enrico; Basciu, Alessio; Ornaghi, Diego; Gallotti, Roberto; Tarelli, Giuseppe

2009-07-01

Reimplantation valve-sparing aortic root replacement has been increasingly performed with improving perioperative and mid-term results. The success of this operation primarily depends on preserving the highly sophisticated dynamic function of the aortic valve by recreating an anatomical three-dimensional configuration similar to the normal aortic root, thus minimizing the mechanical stress and strain on the cusps. Over the years several techniques have been proposed to reproduce the sinuses of Valsalva. We reviewed our experience with aortic valve reimplantation by means of a modified Dacron graft that incorporates sinuses of Valsalva, in a series of 100 consecutive patients. During a 60-month period, 100 patients with aortic root aneurysm underwent aortic valve reimplantation using the Gelweave Valsalva prosthesis. There were 74 males and the mean age was 60+/-12 years (range 28-83 years). Five patients had the Marfan's syndrome, 15 had a bicuspid aortic valve. Cusp repair was performed in five patients. The mean follow-up time was 28.6 months (range 1-60). Transesophageal echocardiogram was performed at the end of each procedure to assess the aortic valve in terms of competence, dynamic motion and level of coaptation within the graft. There was one hospital death and two late deaths. Overall survival at 60 months was 91.7+/-5.1%. Five patients developed severe aortic incompetence (AI) during follow-up requiring aortic valve replacement (AVR). The 60 months freedom from re-operation due to AI was 90.9+/-4.4%. One patient had moderate AI at latest echocardiographic study. The 60 months freedom from AI>2+ was 91.6+/-7.9%. Cox regression identified cusp's repair as independent risk factor (P=0.001) for late reimplantation failure (AVR or AI>2+). There were no episodes of endocarditis and the majority of the patients (88%) were in New York Heart Association functional class I. The aortic valve reimplantation with the Gelweave Valsalva prosthesis provided satisfactory

A study of extracellular matrix remodeling in aortic heart valves using a novel biaxial stretch bioreactor.

Science.gov (United States)

Lei, Ying; Masjedi, Shirin; Ferdous, Zannatul

2017-11-01

In aortic valves, biaxial cyclic stretch is known to modulate cell differentiation, extracellular matrix (ECM) synthesis and organization. We designed a novel bioreactor that can apply independent and precise stretch along radial and circumferential directions in a tissue culture environment. While this bioreactor can be used for either native or engineered tissues, this study determined matrix remodeling and strain distribution of aortic cusps after culturing under biaxial stretch for 14 days. The contents of collagen and glycosaminoglycans were determined using standard biochemical assays and compared with fresh controls. Strain fields in static cusps were more uniform than those in stretched cusps, which indicated degradation of the ECM fibers. The glycosaminoglycan content was significantly elevated in the static control as compared to fresh or stretched cusps, but no difference was observed in collagen content among the groups. The strain profile of freshly isolated fibrosa vs. ventricularis and left, right, and noncoronary cusps were also determined by Digital Image Correlation technique. Distinct strain patterns were observed under stretch on fibrosa and ventricularis sides and among the three cusps. This work highlights the critical role of the anisotropic ECM structure for proper functions of native aortic valves and the beneficial effects of biaxial stretch for maintenance of the native ECM structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structure and function of the tricuspid and bicuspid regurgitant aortic valve: an echocardiographic study.

Science.gov (United States)

Rönnerfalk, Mattias; Tamás, Éva

2015-07-01

The emerging new treatment options for aortic valve disease call for more sophisticated diagnostics. We aimed to describe the echocardiographic pathophysiology and characteristics of the purely regurgitant aortic valve in detail. Twenty-nine men, with chronic aortic regurgitation without concomitant heart disease referred for aortic valve intervention, underwent 2D transoesophageal echocardiographic (TEE) examination prior to surgery according to a previously published matrix. Measurements of the aortic valve apparatus in long and short axis view were made in systole and diastole and analysed off-line. The aortic valves were grouped as tricuspid (TAV) or bicuspid (BAV), and classified by regurgitation mechanism. Twenty-four examinations were eligible for analysis of which 13 presented TAV and 11 BAV. The regurgitation mechanism was classified as dilatation of the aorta in 6 cases, as prolapse in 11 cases and as poor cusp tissue quality or quantity in 7 cases. The ventriculo-aortic junction (VAJ) and valve opening were closely related (TAV r = 0.5, BAV r = 0.73) but no correlation was found between the VAJ and the maximal sinus diameter (maxSiD) or the sinotubular junction (STJ). However, the STJ and maxSiD were significantly related (TAV vs BAV: systole r = 0.9, r = 0.8; diastole r = 0.9, r = 0.7), forming an entity. The conjoined BAV cusps were shorter than the anterior cusps when closed (P = 0.002); the inter-commissural distances of the cusps in the BAV group were significantly different (P = 0.001 resp. 0.03) in both systole and diastole. The VAJ was independent of other aortic dimensions and should thereby be considered as a separate entity with influence on valve opening. The detailed 2D TEE measurements of this study add further important information to our knowledge about the function and echocardiographic anatomy of the pathological aortic valve and root either as a stand-alone examination or as a benchmark and complement to 3D echocardiography. This may

[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.

[Pannus Formation Six-years after Aortic and Mitral Valve Replacement with Tissue Valves;Report of a Case].

Science.gov (United States)

Nakamura, Makoto; Muraoka, Arata; Aizawa, Kei; Akutsu, Hirohiko; Kurumisawa, Soki; Misawa, Yoshio

2015-07-01

A 77-year-old man presented with exertional dyspnea. He had undergone aortic and mitral valve replacement with tissue valves 6-years earlier. The patient's hemoglobin level was 9.8 g/dl and serum aspartate aminotransferase (70 mU/ml) and lactate dehydrogenase (1,112 mU/ml) were elevated. Echocardiography revealed stenosis of the prosthetic valve in the aortic position with peak flow velocity of 3.8 m/second and massive mitral regurgitation. The patient underwent repeat valve replacement. Pannus formation around both implanted valves was observed. The aortic valve orifice was narrowed by the pannus, and one cusp of the prosthesis in the mitral position was fixed and caused the regurgitation, but they were free from cusp laceration or calcification. The patient's postoperative course was uneventful, and he continues to do well 14 months after surgery.

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.

Electromagnetic Ion Cyclotron Waves in the High Altitude Cusp: Polar Observations

Science.gov (United States)

Le, Guan; Blanco-Cano, X.; Russell, C. T.; Zhou, X.-W.; Mozer, F.; Trattner, K. J.; Fuselier, S. A.; Anderson, B. J.; Vondrak, Richard R. (Technical Monitor)

2001-01-01

High-resolution magnetic field data from the Polar Magnetic Field Experiment (MFE) show that narrow band waves at frequencies approximately 0.2 to 3 Hz are a permanent feature in the vicinity of the polar cusp. The waves have been found in the magnetosphere adjacent to the cusp (both poleward and equatorward of the cusp) and in the cusp itself. The occurrence of waves is coincident with depression of magnetic field strength associated with enhanced plasma density, indicating the entry of magnetosheath plasma into the cusp region. The wave frequencies are generally scaled by the local proton cyclotron frequency, and vary between 0.2 and 1.7 times local proton cyclotron frequency. This suggests that the waves are generated in the cusp region by the precipitating magnetosheath plasma. The properties of the waves are highly variable. The waves exhibit both lefthanded and right-handed polarization in the spacecraft frame. The propagation angles vary from nearly parallel to nearly perpendicular to the magnetic field. We find no correlation among wave frequency, propagation angle and polarization. Combined magnetic field and electric field data for the waves indicate that the energy flux of the waves is guided by the background magnetic field and points downward toward the ionosphere.

Electromagnetic Ion Cyclotron Waves in the High-Altitude Cusp: Polar Observations

Science.gov (United States)

Le, G.; Blanco-Cano, X.; Russell, C. T.; Zhou, X.-W.; Mozer, F.; Trattner, K. J.; Fuselier, S. A.; Anderson, B. J.

2005-01-01

High-resolution magnetic field data from the Polar Magnetic Field Experiment (MFE) show that narrow-band waves at frequencies approx. 0.2-3 Hz are a permanent feature in the vicinity of the polar cusp. The waves have been found in the magnetosphere adjacent to the cusp (both poleward and equatorward of the cusp) and in the cusp itself. The occurrence of waves is coincident with depression of magnetic field strength associated with enhanced plasma density, indicating the entry of magnetosheath plasma into the cusp region. The wave frequencies are generally scaled by the local proton cyclotron frequency and vary between 0.2 and 1.7 times local proton cyclotron frequency. This suggests that the waves are generated in the cusp region by the precipitating magnetosheath plasma. The properties of the waves are highly variable. The waves exhibit both left-handed and right-handed polarization in the spacecraft frame. The propagation angles vary from nearly parallel to nearly perpendicular to the magnetic field. We find no correlation among wave frequency, propagation angle, and polarization. Combined magnetic field and electric field data for the waves indicate that the energy flux of the waves is guided by the background magnetic field and points downward toward the ionosphere.

A quarter of a century of experience with aortic valve-sparing operations.

Science.gov (United States)

David, Tirone E; Feindel, Christopher M; David, Carolyn M; Manlhiot, Cedric

2014-09-01

To examine the late outcomes of aortic valve-sparing operations to treat patients with aortic root aneurysm with and without aortic insufficiency (AI) in a cohort of patients followed up prospectively since 1988. A total of 371 consecutive patients had undergone aortic valve-sparing surgery (mean age, 47 ± 15 years; 78% men) from 1988 through 2010. In addition to the aortic root aneurysm, 47% had moderate or severe AI, 35.5% had Marfan syndrome, 12.1% had type A aortic dissection, 9.2% had bicuspid aortic valve, 8.4% had mitral insufficiency, 16.1% had aortic arch aneurysm, and 10.2% had coronary artery disease. Reimplantation of the aortic valve was used in 296 patients and remodeling of the aortic root in 75. Cusp repair by plication of the free margin along the nodule of Arantius was used in 36.6% of patients, and reinforcement of the free margin with a double layer of fine Gore-Tex suture in 24.2%. The patients were followed up prospectively with images of the aortic root for a median follow-up of 8.9 ± 5.2 years. A total of 4 operative and 39 late deaths occurred. Survival at 18 years was 76.8% ± 4.31%, lower than that for the general population matched for age and gender. Age, type A aortic dissection, impaired ventricular function, and preoperative AI were associated with increased mortality on multivariable analysis. Reoperations on the aortic valve were performed in 8 patients for recurrent AI and in 2 for infective endocarditis. Freedom from reoperation on the aortic valve at 18 years was 94.8% ± 2.0%. No predictors of the need for reoperation were found on multivariable analysis. Eighteen patients developed AI greater than mild. Freedom from AI greater than mild at 18 years was 78.0% ± 4.8%. No predictors of recurrent AI were identified on multivariable analysis. Aortic valve-sparing operations continue to provide excellent clinical outcomes, although a slow but progressive deterioration of aortic valve function seems to occur during the first 2

Magnetic field structure influence on primary electron cusp losses for micro-scale discharges

International Nuclear Information System (INIS)

Dankongkakul, Ben; Araki, Samuel J.; Wirz, Richard E.

2014-01-01

An experimental effort was used to examine the primary electron loss behavior for micro-scale (≲3 cm diameter) discharges. The experiment uses an electron flood gun source and an axially aligned arrangement of ring-cusps to guide the electrons to a downstream point cusp. Measurements of the electron current collected at the point cusp show an unexpectedly complex loss pattern with azimuthally periodic structures. Additionally, in contrast to conventional theory for cusp losses, the overall radii of the measured collection areas are over an order of magnitude larger than the electron gyroradius. Comparing these results to Monte Carlo particle tracking simulations and a simplified analytical analysis shows that azimuthal asymmetries of the magnetic field far upstream of the collection surface can substantially affect the electron loss structure and overall loss area

Incidence and progression of mild aortic regurgitation after Tirone David reimplantation valve-sparing aortic root replacement.

Science.gov (United States)

Stephens, Elizabeth H; Liang, David H; Kvitting, John-Peder Escobar; Kari, Fabian A; Fischbein, Michael P; Mitchell, R Scott; Miller, D Craig

2014-01-01

The study objective was to determine whether recurrent or residual mild aortic regurgitation, which occurs after valve-sparing aortic root replacement, progresses over time. Between 2003 and 2008, 154 patients underwent Tirone David-V valve-sparing aortic root replacement; 96 patients (62%) had both 1-year (median, 12 ± 4 months) and mid-term (62 ± 22 months) transthoracic echocardiograms available for analysis. Age of patients averaged 38 ± 13 years, 71% were male, 31% had a bicuspid aortic valve, 41% had Marfan syndrome, and 51% underwent aortic valve repair, predominantly cusp free margin shortening. Forty-one patients (43%) had mild aortic regurgitation on 1-year echocardiogram. In 85% of patients (n = 35), mild aortic regurgitation remained stable on the most recent echocardiogram (median, 57 ± 20 months); progression to moderate aortic regurgitation occurred in 5 patients (12%) at a median of 28 ± 18 months and remained stable thereafter; severe aortic regurgitation developed in 1 patient, eventually requiring reoperation. Five patients (5%) had moderate aortic regurgitation at 1 year, which did not progress subsequently. Two patients (2%) had more than moderate aortic regurgitation at 1 year, and both ultimately required reoperation. Although mild aortic regurgitation occurs frequently after valve-sparing aortic root replacement, it is unlikely to progress over the next 5 years and should not be interpreted as failure of the valve-preservation concept. Further, we suggest that mild aortic regurgitation should not be considered nonstructural valve dysfunction, as the 2008 valve reporting guidelines would indicate. We need 10- to 15-year follow-up to learn the long-term clinical consequences of mild aortic regurgitation early after valve-sparing aortic root replacement. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Successful catheter ablation of a left anterior accessory pathway from the non-coronary cusp of the aortic valve.

Science.gov (United States)

Laranjo, Sérgio; Oliveira, Mário; Trigo, Conceição

2015-08-01

Left anterior accessory pathways are considered to be rare findings. Catheter ablation of accessory pathways in this location remains a challenging target, and few reports about successful ablation of these accessory pathways are available. We describe our experience regarding a case of a manifest left anterior accessory pathway ablation using radiofrequency energy at the junction of the left coronary cusp with the non-coronary cusp.

Coronary ostium occlusion by coronary cusp displacement in Williams syndrome.

Science.gov (United States)

Shiohama, Tadashi; Fujii, Katsunori; Ebata, Ryota; Funabashi, Nobusada; Matsumiya, Goro; Saito, Yuko Kazato; Takechi, Fumie; Yonemori, Yoko; Nakatani, Yukio; Shimojo, Naoki

2016-06-01

Williams syndrome is a contiguous gene deletion syndrome resulting from a heterozygous deletion on chromosome 7q11.23, and is characterized by distinctive facial features and supravalvular aortic stenosis (SVAS). This syndrome rarely presents unpredictable cardiac death, and yet, as illustrated in the present case, it is still not possible to predict it, even on close monitoring. We herein describe the case of a 6-year-old Japanese girl with Williams syndrome, who had sudden cardiac collapse due to cardiac infarction after pharyngitis. Cardiac failure followed a critical course that did not respond to catecholamine support or heart rest with extracardiac mechanical support. Although marked coronary stenosis was not present, the left coronary cusp abnormally adhered to the aortic wall, which may synergistically cause coronary ostium occlusion with SVAS. Altered hemodynamic state, even that caused by the common cold, may lead to critical myocardial events in Williams syndrome with SVAS. © 2015 Japan Pediatric Society.

Type A aortic dissection associated with Dietzia maris.

Science.gov (United States)

Reyes, Guillermo; Navarro, José-Luis; Gamallo, Carlos; delas Cuevas, María-Carmen

2006-10-01

Aortitis is a rare cause of aortic dissection. We report the unusual presentation of a 77-year-old male patient who underwent emergency surgery for an aortic dissection type A. A purulent pericardial fluid and inflammatory aorta were found after chest opening. Several samples were sent for analysis. The ascending aorta presented a mild dilatation with a large haematoma infiltrating the aortic root. The distal part of the ascending aorta seemed unaffected. The aortic rupture was found one centimetre above the non-coronary cusp. Aortic wall tissues were extremely fragile and with an inflammatory aspect. The patient died in the theatre room. In the histological study one out of three fragments of ascending aorta displayed longitudinal splitting of the outer media, with blood extravasation in the adventitial layer. In this level, the presence of a detritus material that reminded of bacterial colonies was noteworthy, together with abundant fibrinous exudates. In the laboratory a new specimen, Dietzia maris, was found in the pericardial liquid and in the aortic wall. We believe that this is the first reported finding of Dietzia maris in a patient with aortic disease.

Residual and Progressive Aortic Regurgitation After Valve-Sparing Root Replacement: A Propensity-Matched Multi-Institutional Analysis in 764 Patients.

Science.gov (United States)

Kari, Fabian A; Doll, Kai-Nicolas; Hemmer, Wolfgang; Liebrich, Markus; Sievers, Hans-Hinrich; Richardt, Doreen; Reichenspurner, Hermann; Detter, Christian; Siepe, Matthias; Czerny, Martin; Beyersdorf, Friedhelm

2016-04-01

Residual/progressive aortic regurgitation (rAR, pAR) after valve-sparing aortic root replacement (V-SARR) can lead to reoperations. We sought to characterize risk factors of mild rAR and pAR after V-SARR in a multicenter cohort. The effect of additional cusp repair on valve function was analyzed using propensity matching. A total of 1,015 patients after V-SARR were identified with (n = 288, 28%) or without additional cusp/commissure repair (n = 727, 72%) at four cardiac units in Germany. A total of 764 patients fulfilling transthoracic echocardiography follow-up-criteria comprised the study cohort. Logistic regression was used for risk factor analysis with endpoints rAR, new onset AR, and pAR. t tests and analyses of variance were used for between-group differences. The effects of additional cusp repair on valve function were studied comparing propensity-matched quintiles. The incidence of rAR was 29%, with influencing factors aneurysm size (p = 0.07) and preoperative aortic valve function (p = 0.08). It was found more often among nonsyndromic patients (34% vs. 14%; OR, 0.4; p < 0.001). Progression of rAR was detectable in 30% after a mean of 4.3 years. The progression rate of rAR ∼ 0.3 grades per patient-year within the first 5 years. When quintiles identified by propensity score were compared, additional cusp repair was linked to new onset AR (p = 0.016) while it was not linked to rAR (p = 0.14) or pAR (p = 0.5). The incidences of rAR and pAR are considerable after V-SARR. Patients should be operated on before large aneurysms are present. New onset AR after an initially good functional result is more likely after an additional cusp repair, while rAR and pAR are not influenced by cusp repair. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Association of aortic valve calcification severity with the degree of aortic regurgitation after transcatheter aortic valve implantation.

Science.gov (United States)

Koos, Ralf; Mahnken, Andreas Horst; Dohmen, Guido; Brehmer, Kathrin; Günther, Rolf W; Autschbach, Rüdiger; Marx, Nikolaus; Hoffmann, Rainer

2011-07-15

This study sought to examine a possible relationship between the severity of aortic valve calcification (AVC), the distribution of AVC and the degree of aortic valve regurgitation (AR) after transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS). 57 patients (22 men, 81 ± 5 years) with symptomatic AS and with a logistic EuroSCORE of 24 ± 12 were included. 38 patients (67%) received a third (18F)-generation CoreValve® aortic valve prosthesis, in 19 patients (33%) an Edwards SAPIEN™ prosthesis was implanted. Prior to TAVI dual-source computed tomography for assessment of AVC was performed. To determine the distribution of AVC the percentage of the calcium load of the most severely calcified cusp was calculated. After TAVI the degree of AR was determined by angiography and echocardiography. The severity of AR after TAVI was related to the severity and distribution of AVC. There was no association between the distribution of AVC and the degree of paravalvular AR after TAVI as assessed by angiography (r = -0.02, p = 0.88). Agatston AVC scores were significantly higher in patients with AR grade ≥ 3 (5055 ± 1753, n = 3) than in patients with AR grade AVC scores > 3000 were associated with a relevant paravalvular AR and showed a trend for increased need for second manoeuvres. There was a significant correlation between the severity of AVC and the degree of AR after AVR (r = 0.50, p AVC have an increased risk for a relevant AR after TAVI as well as a trend for increased need for additional procedures. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Aortic valve-sparing surgery in Marfan syndrome.

Science.gov (United States)

Nachum, Eyal; Shinfeld, Amichay; Kogan, Alexander; Preisman, Sergey; Levin, Shany; Raanani, Ehud

2013-08-01

Patients with Marfan syndrome are referred for cardiac surgery due to root aneurysm with or without aortic valve regurgitation. Because these patients are young and frequently present with normal-appearing aortic cusps, valve sparing is often recommended. However, due to the genetic nature of the disease, the durability of such surgery remains uncertain. Between February 2004 and June 2012, 100 patients in our department suffering from aortic aneurysm with aortic valve regurgitation underwent elective aortic valve-sparing surgery. Of them, 30 had Marfan syndrome, were significantly younger (30 +/- 13 vs. 53 +/- 16 years), and had a higher percentage of root aneurysm, compared with ascending aorta aneurysm in their non-Marfan counterparts. We evaluated the safety, durability, clinical and echocardiographic mid-term results of these patients. While no early deaths were reported in either group, there were a few major early complications in both groups. At follow-up (reaching 8 years with a mean of 34 +/- 26 months) there were no late deaths, and few major late complications in the Marfan group. Altogether, 96% and 78% of the patients were in New York Heart Association functional class I-II in the Marfan and non-Marfan groups respectively. None of the Marfan patients needed reoperation on the aortic valve. Freedom from recurrent aortic valve regurgitation > 3+ was 94% in the Marfan patients. Aortic valve-sparing surgery in Marfan symdrome patients is safe and yields good mid-term clinical outcomes.

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

International Nuclear Information System (INIS)

Mirkhani, S.H.; Golestani, M.G.; Hosini, M.; Kazemian, A.

1999-01-01

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

Aortic valve-sparing operations in aortic root aneurysms: remodeling or reimplantation?

Science.gov (United States)

Rahnavardi, Mohammad; Yan, Tristan D; Bannon, Paul G; Wilson, Michael K

2011-08-01

successful restoration of normal cusp geometry are the keys to success in aortic valve-sparing operations.

Aortic valve calcification as a predictor of location and severity of paravalvular regurgitation after transcatheter aortic valve implantation.

Science.gov (United States)

Koh, Ezra Y; Lam, Kayan Y; Bindraban, Navin R; Cocchieri, Riccardo; Planken, R Nils; Koch, Karel T; Baan, Jan; de Mol, Bas A; Marquering, Henk A

2015-03-01

To determine whether the location of aortic valve calcium (AVC) influences the location of paravalvular regurgitation (PR). PR is an adverse effect of transcatheter aortic valve implantation (TAVI) with a negative effect on long-term patient survival. The relationship between AVC and the occurrence of PR has been documented. However, the relationship between the distribution of AVC and the location of PR is still sparsely studied. The purpose of this study was to correlate severity and location of AVC with PR in patients treated with TAVI. Fifty-six consecutive patients who underwent transaortic or transapical TAVI and had preoperative computed tomography scans were included in this retrospective study. The volume, mass and location of AVC was determined and compared between patients with and without PR using a non-parametric t-test. Postoperative echocardiography was performed to determine the presence and location of PR, which was associated with the cusp with highest AVC using a χ(2) test. Valve deployment was successful in all 56 patients. PR was present in 38 patients (68%) after TAVI. There was a non-significantly higher volume of AVC in the PR group [214 (70-418) vs 371 (254-606) cm(3), P = 0.15]. AVC mass was significantly higher in patients with PR than in patients without PR [282 (188-421) vs 142 (48-259) mg, respectively, P = 0.043]. The location of PR was determined in 36 of these patients. Of these 36 patients, PR occurred at the cusp with the highest AVC in 20 patients (56%, χ(2) P = 0.030). In our population, PR was associated with greater AVC mass. Moreover, the location of PR was associated with the cusp with the highest amount of AVC. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Risk Factors for Late Aortic Valve Dysfunction After the David V Valve-Sparing Root Replacement.

Science.gov (United States)

Esaki, Jiro; Leshnower, Bradley G; Binongo, Jose N; Lasanajak, Yi; McPherson, LaRonica; Guyton, Robert A; Chen, Edward P

2017-11-01

Valve-sparing root replacement (VSRR) is an established therapy for aortic root pathology. However, late aortic valve dysfunction requiring reoperation remains a primary concern of this procedure. This study examines risk factors for late aortic insufficiency (AI) and aortic stenosis (AS) after David V VSRR. A retrospective review from 2005 to 2015 at a US academic center identified 282 patients who underwent VSRR. Cox proportional hazards regression analysis was used to identify risk factors for late AI and AS after VSRR. The mean age was 46.4 years. Sixty-four patients (22.7%) had bicuspid valves, and 41 patients (14.5%) had Marfan syndrome. The incidence of reoperations was 27 (9.6%), and 42 cases (14.9%) presented with acute type A dissection. Operative mortality was 8 (2.8%). Seven-year survival was 90.9%. Seven-year cumulative incidence of reoperation, greater than 2+ AI and greater than moderate AS were 3.1%, 2.2%, and 0.8%, respectively. Multivariable analysis showed aortic root size 55 mm or larger (hazard ratio 3.44, 95% confidence interval: 1.27 to 9.29, p = 0.01) to be a risk factor for late AI whereas bicuspid valve (hazard ratio 16.07, 95% confidence interval: 3.12 to 82.68, p = 0.001) and cusp repair were found to be risk factors (hazard ratio 5.91, 95% confidence interval: 1.17 to 29.86, p = 0.03) for late AS. Valve-sparing root replacement can be performed with low operative risk and good overall long-term survival even in complex clinical settings. Durable valve function can be expected; however, aortic root size 55 cm or more, bicuspid valve anatomy, and cusp repair represent independent risk factors for late aortic valve dysfunction after these procedures. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

The outcome after aortic valve-sparing (David) operation in 179 patients: a single-centre experience.

Science.gov (United States)

Leontyev, Sergey; Trommer, Constanze; Subramanian, Sreekumar; Lehmann, Sven; Dmitrieva, Yaroslava; Misfeld, Martin; Mohr, Friedrich W; Borger, Michael A

2012-08-01

The David aortic valve-sparing reimplantation (AVr-D) operation is increasingly being used in patients with aortic root aneurysmal disease and pliable aortic cusps. The objective of this study was to assess our early and medium-term outcomes with the AVr-D operation. Between 2003 and 2011, a total of 179 patients underwent AVr-D procedures. The mean patient age was 49.7 ± 15.1 years, and 23.5% (n = 42) were females. Marfan syndrome was present in 17.3% of patients (n = 31), and acute Type A aortic dissection in 15.6% (n = 28). Clinical follow-up was 100% complete and was 1.8 ± 1.6 years (0 days to 7.5 years) long. Echocardiographic follow-up was performed 2.2 ± 1.5 years (0 days to 7.5 years) postoperatively and was 77% complete. Early mortality was 1.1% (n = 2), with both deaths occurring in patients with Type A dissection. Pre-discharge echocardiography revealed no patients with >2+ aortic insufficiency (AI), 19.6% of patients (n = 34) with 1+ or 2+ AI and 80.4% of patients (n = 145) with trace or no AI. Left ventricular end-diastolic diameters decreased significantly from 5.6 ± 0.9 to 5.1 ± 0.8 cm early postoperatively (P valve re-replacement during follow-up, two due to early endocarditis and two due to non-coronary leaflet prolapse in Marfan patients. Five-year freedom from aortic valve reoperation was 95.9 ± 2.0%. AVr-D is associated with a low mortality and morbidity rate, even in patients with Type A aortic dissection. Although a slightly higher rate of recurrent AI may be present in patients with Marfan syndrome, freedom from recurrent AI and reoperation remains excellent during medium-term follow-up. The David operation should be considered the gold standard for patients with proximal aortic root pathology (aneurysm or dissection) and pliable aortic cusps.

The dynamic cusp

International Nuclear Information System (INIS)

Potemra, T.A.; Erlandson, R.E.; Zanetti, L.J.; Arnoldy, R.L.; Woch, J.; Friis-Christensen, E.

1992-01-01

A unique alignment of the Viking satellite with respect to a network of magnetometers in Greenland has provided the opportunity to study the relationship of pulsations and plasma characteristics in the dayside cusp. The presence of Pc 1 bursts, Pc 4-5 pulsations, and a tailward traveling twin vortex pattern of ionospheric convection suggests that the magnetosphere may have been temporarily compressed. Magnetic field data acquired at synchrotrons altitude from GOES 5 and on the ground from Huancayo support this suggestion. Plasma with ion dispersion characteristics associated with a cusp during southward IMF was detected by Viking over a 3.5 degree range of latitude. The presence of standing Alfven waves and ring current ions suggest that this cusplike plasma was observed on closed geomagnetic field lines. As Viking moved further poleward, it detected a different region of plasma with characteristics associated with a cusp during northward IMF. The presence of plasma on closed field lines with southward IMF ion dispersion characteristics can be explained with a poleward moving plasma source. The authors suggest that the magnetosphere, during a northward IMF, is temporarily compressed by a solar wind pressure enhancement that produces the Pc 1 bursts, Pc 4-5 pulsations, and ionospheric vortices. As the magnetosphere recovers to its precompressed shape, the source of cusp plasma will move poleward until it reaches an equilibrium position for northward IMF. The Viking satellite, following in the wake of this source, will detect plasma with southward IMF characteristics until it reaches the latitude of the actual northward IMF cusp

Radiological evaluation of ventricular septal defect with aortic insufficiency - An analysis of cineangiography in 15 cases -

International Nuclear Information System (INIS)

Park, Jae Hyung; Yeon, Kyung Mo; Han, Man Chung

1981-01-01

Fifteen cases of ventricular septal defect with aortic insufficiency were diagnosed radiographically and confirmed after operation at Seoul National University Hospital in recent two half years since 1979. Cineangiographies of ascending aorta and left ventricle were done in those cases and revealed some characteristic findings. The results of the analysis are as follow: 1. Among the 15 cases, 14 cases were male and 1 case was female. Age distribution was from 7 years to 23 years. 2. Those 15 cases were corresponded to 8% among total 193 cases of ventricular septal defect, to 11% among total 135 cases of aortic insufficiency and especially to 48% among 48 cases of aortic insufficiency below age of 20 years. 3. After operation, 11 cases were confirmed as subpulmonary type ventricular septal defect and 4 cases as subcristal type. The sizes of the ventricular septal defects were ranged between 0.6 and 2.5 cm in diameter. 4. Regurgitation of contrast media was noticed in cine aortography of all cases, and the grades of regurgitation were II-III/IV in 13 cases. 5. Various types of herniated aortic cusp through ventricular septal defect were seen. In the cases of subpulmonary ventricular septal defect characteristic saccular aneurysm was found in 7 cases. Asymmetry or mild bulging of aortic sinus was found in the cases of subcristal ventricular septal defect. 6. Infundibular stenosis was found in 3 cases with right ventriculography and those were caused by the herniated saccular aneurysm of aortic cusp. 7. It is essential for the diagnosis of ventricular septal defect with aortic insufficiency to undertake biplane cineangiography of ascending aorta and left ventricle in long axial view and right ventriculography should be done in suspicion of infundibular pulmonary stenosis

Inhibitory role of Notch1 in calcific aortic valve disease.

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Asha Acharya

Full Text Available Aortic valve calcification is the most common form of valvular heart disease, but the mechanisms of calcific aortic valve disease (CAVD are unknown. NOTCH1 mutations are associated with aortic valve malformations and adult-onset calcification in families with inherited disease. The Notch signaling pathway is critical for multiple cell differentiation processes, but its role in the development of CAVD is not well understood. The aim of this study was to investigate the molecular changes that occur with inhibition of Notch signaling in the aortic valve. Notch signaling pathway members are expressed in adult aortic valve cusps, and examination of diseased human aortic valves revealed decreased expression of NOTCH1 in areas of calcium deposition. To identify downstream mediators of Notch1, we examined gene expression changes that occur with chemical inhibition of Notch signaling in rat aortic valve interstitial cells (AVICs. We found significant downregulation of Sox9 along with several cartilage-specific genes that were direct targets of the transcription factor, Sox9. Loss of Sox9 expression has been published to be associated with aortic valve calcification. Utilizing an in vitro porcine aortic valve calcification model system, inhibition of Notch activity resulted in accelerated calcification while stimulation of Notch signaling attenuated the calcific process. Finally, the addition of Sox9 was able to prevent the calcification of porcine AVICs that occurs with Notch inhibition. In conclusion, loss of Notch signaling contributes to aortic valve calcification via a Sox9-dependent mechanism.

Valve-sparing aortic root replacement†.

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Koolbergen, David R; Manshanden, Johan S J; Bouma, Berto J; Blom, Nico A; Mulder, Barbara J M; de Mol, Bas A J M; Hazekamp, Mark G

2015-02-01

To evaluate our results of valve-sparing aortic root replacement and associated (multiple) valve repair. From September 2003 to September 2013, 97 patients had valve-sparing aortic root replacement procedures. Patient records and preoperative, postoperative and recent echocardiograms were reviewed. Median age was 40.3 (range: 13.4-68.6) years and 67 (69.1%) were male. Seven (7.2%) patients were younger than 18 years, the youngest being 13.4 years. Fifty-four (55.7%) had Marfan syndrome, 2 (2.1%) other fibrous tissue diseases, 15 (15.5%) bicuspid aortic valve and 3 (3.1%) had earlier Fallot repair. The reimplantation technique was used in all, with a straight vascular prosthesis in 11 (26-34 mm) and the Valsalva prosthesis in 86 (26-32 mm). Concomitant aortic valve repair was performed in 43 (44.3%), mitral valve repair in 10 (10.3%), tricuspid valve repair in 5 (5.2%) and aortic arch replacement in 3 (3.1%). Mean follow-up was 4.2 ± 2.4 years. Follow-up was complete in all. One 14-year old patient died 1.3 years post-surgery presumably of ventricular arrhythmia. One patient underwent reoperation for aneurysm of the proximal right coronary artery after 4.9 years and 4 patients required aortic valve replacement, 3 of which because of endocarditis after 0.1, 0.8 and 1.3 years and 1 because of cusp prolapse after 3.8 years. No thrombo-embolic complications occurred. Mortality, root reoperation and aortic regurgitation were absent in 88.0 ± 0.5% at 5-year follow-up. Results of valve-sparing root replacement are good, even in association with a high incidence of concomitant valve repair. Valve-sparing aortic root replacement can be performed at a very young age as long as an adult size prosthesis can be implanted. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

[Long-term outcome of aortic valve sparing procedures in connective tissue disorders].

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Tanaka, Hiroshi; Ogino, H; Matsuda, H; Minatoya, K; Sasaki, N

2009-10-01

The aim of this study is to determine the long-term outcome of aortic valve sparing procedures for patients having connective tissue disorder. Between 1993 and 2008, the aortic valve sparing surgery was performed in 94 patients having aortic root dilatation. Eighty patients of them (37.2 +/- 13.4 years, 50 male) had cystic medial necrosis in the aortic wall, which was confirmed the pathological examination. We reviewed these patients. Sixty percent (48/80) had Marfan syndrome, 5% (4/80) had Loeyz-Dietz syndrome, 2% (2/80) had bicuspid aortic valve, and 11% (9/80) had aortic dissection. Our reimplantation procedure has been refined as followed: with a tube graft in 41, a tube graft with creation of neo-sinuses in 11, and a Valsalva graft in 14. Fourteen patients underwent the remodeling procedure. The follow-up rate was 100% with the duration of 3.7+/- 3.4 years. There were no operative death but six late deaths. Seventeen (21.3%) patients required aortic valve replacement, for recurrent aortic insufficiency in 13 and infection in 4. Freedom from reoperation was 80%, 43%, and freedom from moderate or severe aortic insufficiency was 80%, 54%, at 5 and 10 years, respectively. Pathological findings of the aortic valve obtained in the reoperations showed elongation and prolapse of the aortic valve due to myxomatous degeneration and fibrous thickening caused by aortic insufficiency. Even in connective tissue disorders, aortic valve sparing operation is associated with acceptable long-term durability, although cusp degeneration resulting in recurrent aortic insufficiency might be progressive.

Relation of Bicuspid Aortic Valve Morphology to the Dilatation Pattern of the Proximal Aorta: Focus on the Transvalvular Flow

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Evaldas Girdauskas

2012-01-01

Full Text Available Whether the dilatation of proximal aorta in patients with bicuspid aortic valve is secondary to hemodynamic effects related to the abnormal aortic valve or a primary manifestation of the genetic disorder remains controversial. We discuss in this paper the recent data on the BAV function and transvalvular flow patterns in relation with the dilatation type of the proximal aorta. Different morphological forms of bicuspid aortic valve in relation with the specific transvalvular blood flow patterns are focus of the first paragraph of this paper. In the second part of this paper we present the pathogenetic insight into the different clinically observed phenotypes of bicuspid aortic valve disease (i.e., association of proximal aortic shapes with the specific cusp fusion patterns, based on the data from recent rheological studies.

The JUPITER registry: 1-year results of transapical aortic valve implantation using a second-generation transcatheter heart valve in patients with aortic stenosis.

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Silaschi, Miriam; Treede, Hendrik; Rastan, Ardawan J; Baumbach, Hardy; Beyersdorf, Friedhelm; Kappert, Utz; Eichinger, Walter; Rüter, Florian; de Kroon, Thomas L; Lange, Rüdiger; Ensminger, Stephan; Wendler, Olaf

2016-11-01

Transcatheter aortic valve replacement (TAVR) is an established therapy for patients with aortic stenosis (AS) at high surgical risk. The JenaValve™ is a second-generation, self-expanding transcatheter heart valve (THV), implanted through transapical access (TA). During stent deployment, a specific 'clipping-mechanism' engages native aortic valve cusps for fixation. We present 1-year outcomes of the JUPITER registry, a post-market registry of the JenaValve for TA-TAVR. The JUPITER registry is a prospective, multicentre, uncontrolled and observational European study to evaluate the long-term safety and effectiveness of the Conformité Européenne-marked JenaValve THV. A total of 180 patients with AS were enrolled between 2012 and 2014. End-points were adjudicated in accordance with the valve academic research consortium document no. 1 definitions. The mean age was 80.4 ± 5.9 years and the mean logistic European system for cardiac operative risk evaluation I 21.2 ± 14.7%. The procedure was successful in 95.0% (171/180), implantation of a second THV (valve-in-valve) was performed in 2.2% (4/180) and conversion to surgical aortic valve replacement (SAVR) was necessary in 2.8% (5/180). No annular rupture or coronary ostia obstruction occurred. Two patients required SAVR after the day of index procedure (1.1%). All-cause mortality at 30 days was 11.1% (20/180), being cardiovascular in 7.2% (13/180). A major stroke occurred in 1.1% (2/180) at 30 days, no additional major strokes were observed during 1 year. All-cause mortality after 30 days was 13.1% (21/160) and combined efficacy at 1 year was 80.8% (122/151). At 1-year follow-up, no patient presented with more than moderate paravalvular leakage, while 2 patients (3.2%) showed moderate, 12 (19.0%) mild and 49 (82.4%) trace/none paravalvular regurgitation. In a high-risk cohort of patients undergoing TA-TAVR for AS, the use of the JenaValve THV is safe and effective. In patients at higher risk for coronary ostia

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. Copyright © 2015 Elsevier Inc. All rights reserved.

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

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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.)

Aortic intracardiac echocardiography-guided septal puncture during mitral valvuloplasty.

Science.gov (United States)

Akkaya, Emre; Vuruskan, Ertan; Zorlu, Ali; Sincer, Isa; Kucukosmanoglu, Mehmet; Ardic, Idris; Yilmaz, Mehmet Birhan

2014-01-01

Transoesophageal echocardiography (TEE) and venous intracardiac echocardiography (ICE) are traditionally used to visualize the interatrial septum (IAS) and the tenting effect of the fossa ovalis in patients undergoing percutaneous balloon mitral valvuloplasty (PBMV). The aim of the present study was to assess the comparative efficacy and safety of arterial (intra-aortic) ICE and venous ICE, compared with TEE (traditional approach), in the patients undergoing PBMV. TEE, aortic ICE, and venous ICE were consecutively performed in 50 patients (40 ± 9 years, 86% female). The images of intracardiac structures were obtained from both aortic and right atrial loci. The IAS was visualized using TEE, aortic ICE, and venous ICE. The mean mitral valve area was 1.14 ± 0.2 cm(2), and the mean left atrial volume index was 57.5 ± 12 mL/m(2). The mean size of the visualized septal length was 48 ± 5 mm by TEE, 51 ± 5 mm by aortic ICE, and 33 ± 6 mm by venous ICE. The Bland-Altman test indicated that the 95% limits of agreement for the measurement of septal diameter ranged from -11.0 to +5.9 mm (mean -2.5 mm) between TEE and aortic ICE, -2.8 to +33.5 mm (mean +15.3 mm) between TEE and venous ICE, and -36.6 to +0.8 mm (mean -17.9 mm) between venous and aortic ICE. Standard venous ICE generally tended to yield smaller values compared with TEE and aortic ICE for the measurement of septal length. Furthermore, the view of fossa ovalis and 'tenting effect' was optimal in 11 patients on venous ICE; however, the fossa ovalis and tip of the needle were well visualized in all patients on aortic ICE (P < 0.001). There were no major complications with the use of aortic ICE. Aortic ICE is a superior alternative to venous ICE and facilitates trans-septal puncture in patients with mitral stenosis.

Cusps in K->3{pi} decays

Energy Technology Data Exchange (ETDEWEB)

Colangelo, G. [Institute for Theoretical Physics, University of Bern, Sidlerstr. 5, CH-3012 Bern (Switzerland); Gasser, J. [Institute for Theoretical Physics, University of Bern, Sidlerstr. 5, CH-3012 Bern (Switzerland); Kubis, B. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, Nussallee 14-16, D-53115 Bonn (Germany); Rusetsky, A. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, Nussallee 14-16, D-53115 Bonn (Germany)]. E-mail: rusetsky@itkp.uni-bonn.de

2006-07-06

pion mass difference generates a pronounced cusp in K->3{pi} decays. As has recently been pointed out by Cabibbo and Isidori, an accurate measurement of the cusp may allow one to pin down the S-wave {pi}{pi} scattering lengths to high precision. Here, we present and illustrate an effective field theory framework that allows one to determine the structure of this cusp in a straightforward manner. The strictures imposed by analyticity and unitarity are respected automatically.

Cusps in K->3π decays

International Nuclear Information System (INIS)

Colangelo, G.; Gasser, J.; Kubis, B.; Rusetsky, A.

2006-01-01

The pion mass difference generates a pronounced cusp in K->3π decays. As has recently been pointed out by Cabibbo and Isidori, an accurate measurement of the cusp may allow one to pin down the S-wave ππ scattering lengths to high precision. Here, we present and illustrate an effective field theory framework that allows one to determine the structure of this cusp in a straightforward manner. The strictures imposed by analyticity and unitarity are respected automatically

Cusp effects in meson decays

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Kubis B.

2010-04-01

Full Text Available The pion mass difference generates a pronounced cusp in the π0 π0 invariant mass distribution of K+ → π0 π0 π+ decays. As originally pointed out by Cabibbo, an accurate measurement of the cusp may allow one to pin down the S-wave pion–pion scattering lengths to high precision. We present the non-relativistic effective field theory framework that permits to determine the structure of this cusp in a straightforward manner, including the effects of radiative corrections. Applications of the same formalism to other decay channels, in particular η and η′ decays, are also discussed.

Protection motivation theory and cigarette smoking among vocational high school students in China: a cusp catastrophe modeling analysis.

Science.gov (United States)

Xu, Yunan; Chen, Xinguang

2016-01-01

Tobacco use is one of the greatest public health problems worldwide and the hazards of cigarette smoking to public health call for better recognition of cigarette smoking behaviors to guide evidence-based policy. Protection motivation theory (PMT) provides a conceptual framework to investigate tobacco use. Evidence from diverse sources implies that the dynamics of smoking behavior may be quantum in nature, consisting of an intuition and an analytical process, challenging the traditional linear continuous analytical approach. In this study, we used cusp catastrophe, a nonlinear analytical approach to test the dual-process hypothesis of cigarette smoking. Data were collected from a random sample of vocational high school students in China ( n = 528). The multivariate stochastic cusp modeling was used and executed with the Cusp Package in R. The PMT-based Threat Appraisal and Coping Appraisal were used as the two control variables and the frequency of cigarette smoking (daily, weekly, occasional, and never) in the past month was used as the outcome variable. Consistent with PMT, the Threat Appraisal (asymmetry, α 1 = 0.1987, p < 0.001) and Coping Appraisal (bifurcation, β 2 = 0.1760, p < 0.05) significantly predicted the smoking behavior after controlling for covariates. Furthermore, the cusp model performed better than the alternative linear and logistic regression models with regard to higher R 2 (0.82 for cusp, but 0.21 for linear and 0.25 for logistic) and smaller AIC and BIC. Study findings support the conclusion that cigarette smoking in adolescents is a quantum process and PMT is relevant to guide studies to understand smoking behavior for smoking prevention and cessation.

Statistical Study in the mid-altitude cusp region: wave and particle data comparison using a normalized cusp crossing duration

Science.gov (United States)

Grison, B.; Escoubet, C. P.; Pitout, F.; Cornilleau-Wehrlin, N.; Dandouras, I.; Lucek, E.

2009-04-01

In the mid altitude cusp region the DC magnetic field presents a diamagnetic cavity due to intense ion earthward flux coming from the magnetosheath. A strong ultra low frequency (ULF) magnetic activity is also commonly observed in this region. Most of the mid altitude cusp statistical studies have focused on the location of the cusp and its dependence and response to solar wind, interplanetary magnetic field, dipole tilt angle parameters. In our study we use the database build by Pitout et al. (2006) in order to study the link of wave power in the ULF range (0.35-10Hz) measured by STAFF SC instrument with the ion plasma properties as measured by CIS (and CODIF) instrument as well as the diamagnetic cavity in the mid-altitude cusp region with FGM data. To compare the different crossings we don`t use the cusp position and dynamics but we use a normalized cusp crossing duration that permits to easily average the properties over a large number of crossings. As usual in the cusp, it is particularly relevant to sort the crossings by the corresponding interplanetary magnetic field (IMF) orientation in order to analyse the results. In particular we try to find out what is the most relevant parameter to link the strong wave activity with. The global statistic confirms previous single case observations that have noticed a simultaneity between ion injections and wave activity enhancements. We will also present results concerning other ion parameters and the diamagnetic cavity observed in the mid altitude cusp region.

Aortic root surgery in Marfan syndrome.

Science.gov (United States)

Sheick-Yousif, Basheer; Sheinfield, Ami; Tager, Salis; Ghosh, Probal; Priesman, Sergey; Smolinsky, Aram K; Raanani, Ehud

2008-03-01

As the shortcomings of the Bentall operation and its variants in the Marfan syndrome have become apparent, the recent cusp-sparing techniques (remodeling or reimplantation) bear promise of better mid-term and long-term outcomes. To examine the results of aortic root surgery in patients with Marfan syndrome. During the period March 1994 to September 2007, 220 patients underwent aortic valve-sparing surgery; 20 were Marfan patients (group 1) who were compared with another 20 Marfan patients undergoing composite aortic root replacement (group 2). Fourteen patients had aortic dissection and 26 had thoracic aortic aneurysm. There were 31 males and 9 females with a mean age of 37.9 +/- 13.8 years. In group 1, reimplantation was used in 13 patients, remodeling in 4, and aortic valve repair with sinotubular junction replacement in 3. In group 2, a mechanical valve conduit was used. Mean logistic Euroscore was 12.27 +/- 14.6% for the whole group, five of whom were emergent cases Group 2 had more previous cardiac procedures compared to group 1 (9 vs. 2, P = 0.03) and shorter cross-clamp time (122 +/- 27.1 vs. 153.9 +/- 23.7 minutes, P = 0.0004). Overall mortality was 10%. Early mortality was 10% in group 2 and 5% in group 1 (NS). Mean follow-up time was 25 months for group 2 and 53 months for group 1. Three patients were reoperated; all had undergone the remodeling. Five year freedom from reoperation and death was 86% and 90% in group 2 and 70% and 95% in group 1 (P = 0.6, P = 0.6), respectively. Late survival of patients with Marfan syndrome was similar in both groups. Root reconstruction tends towards a higher incidence of late reoperations if the remodeling technique is used. We now prefer to use the reimplantation technique.

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/

Tooth cusp sharpness as a dietary correlate in great apes.

Science.gov (United States)

Berthaume, Michael A

2014-02-01

Mammalian molars have undergone heavy scrutiny to determine correlates between morphology and diet. Here, the relationship between one aspect of occlusal morphology, tooth cusp radius of curvature (RoC), and two broad dietary categories, folivory and frugivory, is analyzed in apes. The author hypothesizes that there is a relationship between tooth cusp RoC and diet, and that folivores have sharper teeth than frugivores, and further test the correlation between tooth cusp RoC and tooth cusp size. Eight measures of tooth cusp RoC (two RoCs per cusp) were taken from 53 M(2) s from four species and subspecies of frugivorous apes (Pongo pygmaeus, Pan troglodytes troglodytes, Pan troglodytes schweinfurthii, and Gorilla gorilla gorilla) and two subspecies of folivorous apes (Gorilla beringei beringei, and Gorilla beringei graueri). Phylogenetically corrected ANOVAs were run on the full dataset and several subsets of the full dataset, revealing that, when buccolingual RoCs are taken into account, tooth cusp RoCs can successfully differentiate folivores and frugivores. PCAs revealed that folivores consistently had duller teeth than frugivores. In addition, a weak, statistically significant positive correlation exists between tooth cusp size and tooth cusp RoC. The author hypothesizes differences in tooth cusp RoC are correlated with wear rates, where, per vertical unit of wear, duller cusps will have a longer length of exposed enamel ridge than sharper cusps. More data need to be gathered to determine if the correlation between tooth cusp RoC and tooth cusp size holds true when small primates are considered. Copyright © 2013 Wiley Periodicals, Inc.

Papillary fibroelastoma of the aortic valve - a case report and literature review

Directory of Open Access Journals (Sweden)

Von Canal Friederike

2010-10-01

Full Text Available Abstract The prevalence of primary cardiac tumour ranges from 0.0017-0.28% and papillary fibroelastoma is rare but not uncommon benign cardiac neoplasm. Currently, with the advent of higher-resolution imaging technology especially transoesophageal echocardiography such cases being recognized frequently. The clinical presentation of these tumours varies from asymptomatic to severe ischaemic or embolic complications. We herein, present a 50-year-old female patient with a papillary fibroelastoma of the aortic valve arising from the endocardium of the right coronary cusp very close to the commissure between the right and non-coronary cusps. The patient presented with angina-like chest pain and was investigated using echocardiography and CT angiographic modalities in addition to the usual investigations. The differential diagnosis considered was a thrombus, myxoma, Lambl's excrescence and infective vegetation. The surgical management included a prompt resection of the tumour on cardiopulmonary bypass avoiding injury to the aortic valve. The patient recovered well. A review of the literature suggests that the cardiac papillary fibroelastoma is a rare but potentially treatable cause of embolic stroke and other fatal complications, therefore, a strong suspicion; appropriate use of imaging modality, preoperative anticoagulation and urgent surgical resection is warranted. Also, possibility of this diagnosis should be kept in mind while managing cardiac or valvular tumours.

Density Variations in the Earth's Magnetospheric Cusps

Science.gov (United States)

Walsh, B. M.; Niehof, J.; Collier, M. R.; Welling, D. T.; Sibeck, D. G.; Mozer, F. S.; Fritz, T. A.; Kuntz, K. D.

2016-01-01

Seven years of measurements from the Polar spacecraft are surveyed to monitor the variations of plasma density within the magnetospheric cusps. The spacecraft's orbital precession from 1998 through 2005 allows for coverage of both the northern and southern cusps from low altitude out to the magnetopause. In the mid- and high- altitude cusps, plasma density scales well with the solar wind density (n(sub cusp)/n(sub sw) approximately 0.8). This trend is fairly steady for radial distances greater then 4 R(sub E). At low altitudes (r less than 4R(sub E)) the density increases with decreasing altitude and even exceeds the solar wind density due to contributions from the ionosphere. The density of high charge state oxygen (O(greater +2) also displays a positive trend with solar wind density within the cusp. A multifluid simulation with the Block-Adaptive-Tree Solar Wind Roe-Type Upwind Scheme MHD model was run to monitor the relative contributions of the ionosphere and solar wind plasma within the cusp. The simulation provides similar results to the statistical measurements from Polar and confirms the presence of ionospheric plasma at low altitudes.

Observations of the cusp region under northward IMF

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F. Pitout

2001-09-01

Full Text Available We present a comparative study of the cusp region using the EISCAT Svalbard Radars (ESR and the Cluster spacecraft. We focus in this paper on 2 February 2001, over the time period from 07:30 UT to 12:00 UT when the oblique ESR antenna pointing northward at a low elevation recorded latitudinal motions of the cusp region in response to the IMF. Meanwhile, the Cluster satellites were flying over the EISCAT Svalbard Radar field-of-view around local magnetic noon. The spacecraft first flew near ESR, northeast of Svalbard and then passed over the field-of-view of the antenna at about 11:30 UT. From 08:00 UT to 09:00 UT, the IMF remains primarily southward yet several variations in the Z-component are seen to move the cusp. Around 09:00 UT, an abrupt northward turning of the IMF moves the cusp region to higher latitudes. As a result, the Cluster satellites ended up in the northernmost boundary of the high-altitude cusp region where the CIS instrument recorded highly structured plasma due to ion injections in the lobe of the magnetosphere. After 09:00 UT, the IMF remains northward for more than two hours. Over this period, the ESR records sunward plasma flow in the cusp region due to lobe reconnection, while Cluster spacecraft remain in the high-altitude cusp.Key words. Magnetospheric physics (magnetopause, cusp, and boundary layers; plasma convection Ionosphere (polar ionosphere

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, ...

Valve-Sparing Root Replacement Compared With Composite Valve Graft Procedures in Patients With Aortic Root Dilation.

Science.gov (United States)

Ouzounian, Maral; Rao, Vivek; Manlhiot, Cedric; Abraham, Nachum; David, Carolyn; Feindel, Christopher M; David, Tirone E

2016-10-25

Although aortic valve-sparing (AVS) operations are established alternatives to composite valve graft (CVG) procedures for patients with aortic root aneurysms, comparative long-term outcomes are lacking. This study sought to compare the results of patients undergoing AVS procedures with those undergoing CVG operations. From 1990 to 2010, a total of 616 patients age Marfan syndrome and lower rates of bicuspid aortic valve than those undergoing bio-CVG or m-CVG procedures. In-hospital mortality (0.3%) and stroke rate (1.3%) were similar among groups. After adjusting for clinical covariates, both bio-CVG and m-CVG procedures were associated with increased long-term major adverse valve-related events compared with patients undergoing AVS (hazard ratio [HR]: 3.4, p = 0.005; and HR: 5.2, p valve-related complications when compared with bio-CVG and m-CVG. AVS is the treatment of choice for young patients with aortic root aneurysm and normal or near-normal aortic cusps. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Talon′s cusp: Report of four unusual cases

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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.

The Polar Cusp

International Nuclear Information System (INIS)

Holtet, J.A.; Egeland, A.

1985-01-01

The upper atmosphere at high latitudes is often called the ''earth's window to outer space.'' Through various electrodynamic coupling processes, as well as direct transfer of particles, many of the geophysical effects displayed are direct manifestations of phenomena occurring in deep space. The high latitude ionosphere also exerts a feedback on the regions of the magnetosphere and atmosphere to which it is coupled. 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 processes and a focusing on the ionosphere. In the Polar Cusps, the solar wind plasma also has direct access to the upper atmosphere

Genetic integration of molar cusp size variation in baboons.

Science.gov (United States)

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

2010-06-01

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 our study to include data from the maxillary molar cusps. Here we report on these later analyses, as well as inter-arch comparisons with the mandibular data. We analyzed variation in two-dimensional maxillary molar cusp size using data collected from a captive pedigreed breeding colony of baboons, Papio hamadryas, housed at the Southwest National Primate Research Center. These analyses show that variation in maxillary molar cusp size is heritable and sexually dimorphic. We also estimated additive genetic correlations between cusps on the same crown, homologous cusps along the tooth row, and maxillary and mandibular cusps. The pattern for maxillary molars yields genetic correlations of one between the paracone-metacone and protocone-hypocone. Bivariate analyses of cuspal homologues on adjacent teeth yield correlations that are high or not significantly different from one. Between dental arcades, the nonoccluding cusps consistently yield high genetic correlations, especially the metaconid-paracone and metaconid-metacone. This pattern of genetic correlation does not immediately accord with the pattern of development and/or calcification, however these results do follow predictions that can be made from the evolutionary history of the tribosphenic molar. Copyright 2009 Wiley-Liss, Inc.

High-Energy Electron Confinement in a Magnetic Cusp Configuration

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Jaeyoung Park

2015-06-01

Full Text Available 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.

Preliminary experiments with a cusp-field ion source

International Nuclear Information System (INIS)

Bickes, R.W. Jr.; O'Hagan, J.B.

1980-12-01

Preliminary experiments with a cusp field ion source have been completed. Measurements were made of the total ion current and mass and energy distributions as a function of source operating conditions and cusp field geometry. These experiments have indicated that a cusp field source may be used in the Sandia Neutron Generator for Cancer Therapy and may permit the incorporation of a simplified unpumped accelerator design. Suggestions for future work are briefly outlined

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.

The novel echo-guided ProGlide technique during percutaneous transfemoral transcatheter aortic valve implantation.

Science.gov (United States)

Honda, Yohsuke; Araki, Motoharu; Yamawaki, Masahiro; Tokuda, Takahiro; Tsutumi, Masakazu; Mori, Shinsuke; Sakamoto, Yasunari; Kobayashi, Norihiro; Hirano, Keisuke; Ito, Yoshiaki

2018-04-01

The aim of this study was to assess clinical benefit of the Echo-guided ProGlide technique in patients undergoing percutaneous transfemoral transcatheter aortic valve implantation (TF-TAVI). The efficacy of the Echo-guided ProGlide technique during percutaneous TF-TAVI was not previously clarified. A total of 121 consecutive patients who underwent percutaneous TF-TAVI at our institution between February 2014 and July 2017 were enrolled in this study. According to the introduction of this novel technique in March 2016, patients were divided into two groups (echo-guided group who underwent TAVI from March 2016 to July 2017, n = 63; not echo-guided group who underwent TAVI from February 2014 to February 2016, n = 58). The incidence of major vascular complications, defined per the Valve Academic Research Consortium-2 criteria, and ProGlide complications including acute femoral artery stenosis or occlusion and bleeding requiring any intervention. The incidence of major vascular complication and ProGlide complication were significantly lower in the echo-guided group than in not echo-guided group (1.6% vs 17.2%, P guided ProGlide technique was independently associated with prevention of ProGlide complications (odds ratio, 0.11; 95% confidential interval, 0.01-0.76; P = 0.03). This novel Echo-guided ProGlide technique was associated with a lower rate of major vascular complications, particularly ProGlide complications during percutaneous TF-TAVI. © 2017, Wiley Periodicals, Inc.

Midterm outcome of valve-sparing aortic root replacement in inherited connective tissue disorders.

Science.gov (United States)

Tanaka, Hiroshi; Ogino, Hitoshi; Matsuda, Hitoshi; Minatoya, Kenji; Sasaki, Hiroaki; Iba, Yutaka

2011-11-01

This study determined the midterm outcome of valve-sparing aortic root replacement for patients with inherited connective tissue disorders. From 1993 to 2008, 94 patients underwent valve-sparing aortic root replacement. Sixty patients (64%), average age 33 years (range, 15 to 61 years), had inherited connective tissue disorders: Marfan syndrome, 54 (92%); Loeys-Dietz syndrome, 5 (8%); and smooth muscle α-actin (ACTA2) mutation in 1. Median preoperative sinus diameter was 52 mm (range, 42 to 76 mm), and moderate/severe aortic regurgitation was present in 14 (23%). Seven (12%, 1993 to 1999) underwent remodeling procedures, and 53 had reimplantation procedures. Cusp repair was performed in 4. Median follow-up was 55 months (range, 1 to 149 months). There were 15 patients in the early term (1993 to 2000) and 45 in the late term (2001 to 2008). Four late deaths occurred (cardiac, 3; aortic, 1), with 10-year survival of 86%. Rates of freedom from aortic valve replacement at 5 and 10 years were 85% and 58% in remodeling and 96% and 58% in reimplantation. Risk factors for reoperations were postprocedure intraoperative aortic insufficiency greater than mild (p = 0.046), remodeling procedure (p = 0.016), and early term (p = 0.0002). One patient (2%) with none/trivial postprocedure aortic insufficiency required aortic valve replacement. Freedom from reoperation in patients with none/trivial postprocedure aortic insufficiency at 5 and 10 years was 100% and 67%. Meticulous control of aortic insufficiency during operation would bring favorable midterm durability in valve-sparing aortic root replacement using a reimplantation technique, even in patients with inherited connective tissue disorders. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Localized Models of Charged Particle Motion in Martian Crustal Magnetic Cusps

Science.gov (United States)

Brain, D. A.; Poppe, A. R.; Jarvinen, R.; Dong, Y.; Egan, H. L.; Fang, X.

2017-12-01

The induced magnetosphere of Mars is punctuated by localized but strong crustal magnetic fields that are observed to play host to a variety of phenomena typically associated with global magnetic fields, such as auroral processes and particle precipitation, field-aligned current systems, and ion outflow. Each of these phenomena occur on the night side, in small-scale magnetic `cusp' regions of vertically aligned field. Cusp regions are not yet capable of being spatially resolved in global scale models that include the ion kinetics necessary for simulating charged particle transport along cusps. Local models are therefore necessary if we are to understand how cusp processes operate at Mars. Here we present the first results of an effort to model the kinetic particle motion and electric fields in Martian cusps. We are adapting both a 1.5D Particle-in-Cell (PIC) model for lunar magnetic cusps regions to the Martian case and a hybrid model framework (used previously for the global Martian plasma interaction and for lunar magnetic anomaly regions) to cusps in 2D. By comparing the models we can asses the importance of electron kinetics in particle transport along cusp field lines. In this first stage of our study we model a moderately strong nightside cusp, with incident hot hydrogen plasma from above, and cold planetary (oxygen) plasma entering the simulation from below. We report on the spatial and temporal distribution of plasma along cusp field lines for this initial case.

Impact of primary para-aortic lymphadenectomy on distant failure in locally advanced cervical cancer patients treated in the era of image-guided adaptive brachytherapy.

Science.gov (United States)

Chargari, Cyrus; Mazeron, Renaud; Dunant, Ariane; Gouy, Sébastien; Petit, Claire; Maroun, Pierre; Uzan, Catherine; Annede, Pierre; Bentivegna, Enrica; Balleyguier, Corinne; Genestie, Catherine; Pautier, Patricia; Leary, Alexandra; Lhomme, Catherine; Deutsch, Eric; Morice, Philippe; Haie-Meder, Christine

2016-12-01

To investigate the impact of a primary para-aortic lymphadenectomy (PAL) in locally advanced cervical cancer patients receiving definitive chemoradiation, we reviewed the clinical records of consecutive patients treated in our Institution and receiving an external beam irradiation followed with an image-guided adaptive brachytherapy for a locally advanced cervical cancer. We examined the impact of performing a primary PAL as part of primary staging for guiding irradiation fields in patients without extra-pelvic PET uptake. The outcome of patients presenting para-aortic lymph node uptake (PALNU) was also examined. 186 patients were identified. Median follow-up was 44.4 months. Patients receiving a primary PAL (PAL group) and those who received upfront pelvic chemoradiation (no-PAL group) did not significantly differ for loco-regional failures. Survival without distant failure (DFFS), including para-aortic relapses, was at 3 years 87 % (95 % CI 84-90 %) in PAL group, 67 % (95 % CI 59-85 %) in the no-PAL group and 44 % (95 % CI 32-66 %) in the PALNU group (p = 0.04 for comparison between PAL and no-PAL groups). In a multivariate model including para-aortic lymphadenectomy, pelvic nodal uptake and high-risk clinical target volume as adjustment variables, a para-aortic lymphadenectomy was significant for DFS (HR = 0.47, 95 % CI 0.26-0.84, p = 0.01). Although confounding factors could account for these retrospective results, a primary PAL with tailored irradiation fields based on para-aortic histological findings seems to be associated with a better control for distant metastases. A randomized trial is testing the benefit of this strategy.

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

Directory of Open Access Journals (Sweden)

Achla Bharti Yadav

2015-01-01

Full Text Available 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.

Idiopathic mitral valve prolapse with tricuspid, aortic and pulmonary valve involvement: An autopsy case report

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Heena M Desai

2015-01-01

Full Text Available Mitral valve prolapse (MVP is usually asymptomatic, but can be associated with complications such as infective endocarditis, mitral regurgitation, thromboembolism and sudden cardiac death. It has been very rarely reported to occur in association with other valvular involvement. A 55-year-old male patient was brought dead and at autopsy the mitral valve orifice was stenotic and the leaflets were enlarged, myxoid and bulging suggestive of MVP and chordae tendinae were thickened, stretched and elongated. Similar changes were seen in the tricuspid valve. The pulmonary and aortic valves also showed myxomatous degeneration of their cusps. Myxomatous degeneration is the most common cause of MVP and it can be associated with involvement of the other valves. Concomitant involvement of the aortic valve has been reported, however it is very rare and simultaneous involvement of the pulmonary valve has not been reported in the literature so far. We report a case of MVP associated with myxomatous degeneration of the tricuspid, pulmonary and aortic valves.

Anesthetic management for combined mitral valve replacement and aortic valve repair in a patient with osteogenesis imperfecta

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Huang Jiapeng

2011-01-01

Full Text Available Osteogenesis imperfecta is a rare disorder of connective tissues and presents multiple challenges, including difficult airway, hyperthermia, coagulopathy and respiratory dysfunction, for anesthesiologists, especially during cardiac surgery. We present anesthetic management of a patient with osteogenesis impertecta during double valve surgery. Dexmedetomidine infusion minimized the risks of malignant hyperthermia. Glidescope and in-line stabilization facilitated endotracheal intubation and protected his oral structures and cervical spine. Transesophageal echocardiography (TEE diagnosed a flail A3 segment and redundant left coronary cusp causing mitral and aortic regurgitation. The mitral valve was replaced and the aortic valve repaired. Coagulopathy was corrected according to comprehensive coagulation analysis. Glidescope, dexmedetomidine, coagulation analysis and TEE could facilitate anesthetic management in these patients.

Randomized trial of guiding hypertension management using central aortic blood pressure compared with best-practice care: principal findings of the BP GUIDE study.

Science.gov (United States)

Sharman, James E; Marwick, Thomas H; Gilroy, Deborah; Otahal, Petr; Abhayaratna, Walter P; Stowasser, Michael

2013-12-01

Arm cuff blood pressure (BP) may overestimate cardiovascular risk. Central aortic BP predicts mortality and could be a better method for patient management. We sought to determine the usefulness of central BP to guide hypertension management. This was a prospective, open-label, blinded-end point study in 286 patients with hypertension randomized to treatment decisions guided by best-practice usual care (n=142; using office, home, and 24-hour ambulatory BP) or, in addition, by central BP intervention (n=144; using SphygmoCor). Therapy was reviewed every 3 months for 12 months, and recommendations were provided to each patient and his/her doctor on antihypertensive medication titration. Outcome measures were as follows: medication quantity (daily defined dose), quality of life, and left ventricular mass (3-dimensional echocardiography). There was 92% compliance with recommendations on medication titration, and quality of life improved in both groups (post hoc P0.10), but with intervention there was a significant stepwise decrease in daily defined dose from baseline to 3 months (P=0.008) and each subsequent visit (all P0.05). We conclude that guidance of hypertension management with central BP results in a significantly different therapeutic pathway than conventional cuff BP, with less use of medication to achieve BP control and no adverse effects on left ventricular mass, aortic stiffness, or quality of life.

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.

Latitudinal variation of the polar cusp during a geomagnetic storm

International Nuclear Information System (INIS)

Meng, C.

1982-01-01

Large amplitude latitudinal variation of the polar cusp position was observed during the intense geomagnetic storm of 15--16 February 1980. The observation of the polar cusp, identified as the region of intense but extremely soft electron precipitation, was made by two nearly noon-midnight orbit DMSP satellites over both northern and southern hemispheres. The latitudinal shift of the polar cusp is observed to be related to the intensity variation of the ring current indicated by the hourly Dst values. The polar cusp region moved from its normal location at approx.76 0 gm lat down to approx.62 0 gm lat at the peak of this storm. This movement took about 5 hours and was detected over both hemispheres. A drastic variation in the width of the cusp region was also observed; it is very narrow (approx.1 0 ) during the equatorial shift and expands to > or approx. =5 0 during the poleward recovery. Variation of the polar cusp latitude with that of the Dst index was also seen during the period before the intense storm

Inter-ethnic differences in valve morphology, valvular dysfunction, and aortopathy between Asian and European patients with bicuspid aortic valve.

Science.gov (United States)

Kong, William K F; Regeer, Madelien V; Poh, Kian K; Yip, James W; van Rosendael, Philippe J; Yeo, Tiong C; Tay, Edgar; Kamperidis, Vasileios; van der Velde, Enno T; Mertens, Bart; Ajmone Marsan, Nina; Delgado, Victoria; Bax, Jeroen J

2018-04-14

Transcatheter aortic valve replacement (TAVR) has been shown safe and feasible in patients with bicuspid aortic valve (BAV) morphology. Evaluation of inter-ethnic differences in valve morphology and function and aortic root dimensions in patients with BAV is important for the worldwide spread of this therapy in this subgroup of patients. Comparisons between large European and Asian cohorts of patients with BAV have not been performed, and potential differences between populations may have important implications for TAVR. The present study evaluated the differences in valve morphology and function and aortic root dimensions between two large cohorts of European and Asian patients with BAV. Aortic valve morphology was defined on transthoracic echocardiography according to the number of commissures and raphe: type 0 = no raphe and two commissures, type 1 = one raphe and two commissures, type 2 = two raphes and one commissure. Aortic stenosis and regurgitation were graded according to current recommendations. For this study, aortic root dimensions were manually measured on transthoracic echocardiograms at the level of the aortic annulus, sinus of Valsalva (SOV), sinotubular junction (STJ), and ascending aorta (AA). Of 1427 patients with BAV (45.2 ± 18.1 years, 71.9% men), 794 (55.6%) were Europeans and 633 (44.4%) were Asians. The groups were comparable in age and proportion of male sex. Asians had higher prevalence of type 1 BAV with raphe between right and non-coronary cusps than Europeans (19.7% vs. 13.6%, respectively; P < 0.001), whereas the Europeans had higher prevalence of type 0 BAV (two commissures, no raphe) than Asians (14.5% vs. 6.8%, respectively; P < 0.001). The prevalence of moderate and severe aortic regurgitation was higher in Europeans than Asians (44.2% vs. 26.8%, respectively; P < 0.001) whereas there were no differences in BAV with normal function or aortic stenosis. After adjusting for demographics, comorbidities

JAG Tearing Technique with Radiofrequency Guide Wire for Aortic Fenestration in Thoracic Endovascular Aneurysm Repair

International Nuclear Information System (INIS)

Ricci, Carmelo; Ceccherini, Claudio; Leonini, Sara; Cini, Marco; Vigni, Francesco; Neri, Eugenio; Tucci, Enrico; Benvenuti, Antonio; Tommasino, Giulio; Sassi, Carlo

2012-01-01

An innovative approach, the JAG tearing technique, was performed during thoracic endovascular aneurysm repair in a patient with previous surgical replacement of the ascending aorta with a residual uncomplicated type B aortic dissection who developed an aneurysm of the descending thoracic aorta with its lumen divided in two parts by an intimal flap. The proximal landing zone was suitable to place a thoracic stent graft. The distal landing zone was created by cutting the intimal flap in the distal third of the descending thoracic aorta with a radiofrequency guide wire and intravascular ultrasound catheter.

Black Holes and Galactic Density Cusps II Spherically Symmetric Anisotropic Cusps

CERN Document Server

Henriksen, Richard N; Macmillan, Joseph D

2010-01-01

Aims. In this paper we study density cusps that may contain central black holes. The actual co-eval self-similar growth would not distinguish between the central object and the surroundings. Methods. To study the environment of a growing black hole we seek descriptions of steady 'cusps' that may contain a black hole and that retain at least a memory of self-similarity. We refer to the environment in brief as the 'bulge' and on smaller scales, the 'halo'. Results. We find simple descriptions of the simulations of collisionless matter by comparing predicted densities, velocity dispersions and distribution functions with the simulations. In some cases central point masses may be included by iteration. We emphasize that the co-eval self-similar growth allows an explanation of the black hole bulge mass correlation between approximately similar collisionless systems. Conclusions. We have derived our results from first principles assuming adiabatic self-similarity and either self-similar virialisation or normal stea...

Incremental value of three-dimensional transesophageal echocardiography over two-dimensional transesophageal echocardiography in the assessment of Lambl's excrescences and nodules of Arantius on the aortic valve.

Science.gov (United States)

Dumaswala, Bhavin; Dumaswala, Komal; Hsiung, Ming Chon; Quiroz, Luis David Meggo; Sungur, Aylin; Escanuela, Maximilliano German Amado; Mehta, Kruti; Oz, Tugba Kemaloglu; Bhagatwala, Kunal; Karia, Nidhi M; Nanda, Navin C

2013-09-01

In this retrospective study, we identified 7 cases where Lambl's excrescences were identified by two-dimensional transesophageal echocardiography (2DTEE) and also had live/real time three-dimensional transesophageal echocardiography (3DTEE) studies available for comparison. We subsequently assessed them for the presence of Lambl's excrescences (LE) and nodules of Arantius (NA) on the aortic valve. After their identification, we qualitatively and quantitatively organized our findings by number, cusp location, measurements, and orientation if applicable. A greater number of LE was found by 3DTEE than 2DTEE (19 vs. 11, respectively). In all 3DTEE studies, their cusp attachment site, their x-, y-, and z-axis measurements, and orientation were clearly visualized and described. Only 3DTEE studies provided confident visualization of the cusp attachment sites. Similarly, a greater number of NA was found by 3DTEE than 2DTEE (21 vs. 5, respectively). The triad of NA was visualized in all 3DTEE studies and each was described using its x-, y-, and z- axis measurements. Only three 2DTEE studies provided reliable identification of the NA. In conclusion, we present further evidence of the incremental value of 3DTEE over 2DTEE in the qualitative and quantitative assessment of cardiac structures including LE and NA on the aortic valve. © 2013, Wiley Periodicals, Inc.

Are dayside long-period pulsations related to the cusp?

Directory of Open Access Journals (Sweden)

V. Pilipenko

2015-03-01

Full Text Available We compare simultaneous observations of long-period ultra-low-frequency (ULF wave activity from a Svalbard/IMAGE fluxgate magnetometer latitudinal profile covering the expected cusp geomagnetic latitudes. Irregular Pulsations at Cusp Latitudes (IPCL and narrowband Pc5 waves are found to be a ubiquitous element of ULF activity in the dayside high-latitude region. To identify the ionospheric projections of the cusp, we use the width of return signal of the Super Dual Auroral Radar Network (SuperDARN radar covering the Svalbard archipelago, predictions of empirical cusp models, augmented whenever possible by Defense Meteorological Satellite Program (DMSP identification of magnetospheric boundary domains. The meridional spatial structure of broadband dayside Pc5–6 pulsation spectral power has been found to have a localized latitudinal peak, not under the cusp proper as was previously thought, but several degrees southward from the equatorward cusp boundary. The earlier claims of the dayside monochromatic Pc5 wave association with the open–closed boundary also seems doubtful. Transient currents producing broadband Pc5–6 probably originate at the low-latitude boundary layer/central plasma sheet (LLBL/CPS interface, though such identification with available DMSP data is not very precise. The occurrence of broadband Pc5–6 pulsations in the dayside boundary layers is a challenge to modelers because so far their mechanism has not been firmly identified.

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 τ_G≈ 61 s (or 170 km. The flatness parameter increases to values greater than 3 for scales smaller than τ_G. 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 τ_G 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 τ_G found in the cusp. The flatness analysis confirms the decreasing of τ_G 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

Synthesis of antihydrogen atoms in a CUSP trap

Energy Technology Data Exchange (ETDEWEB)

Kuroda, Naofumi, E-mail: kuroda@phys.c.u-tokyo.ac.jp [University of Tokyo, Graduate School of Arts and Sciences (Japan); Enomoto, Yoshinori [RIKEN Advanced Science Institute (Japan); Michishio, Koji [Tokyo University of Science, Department of Physics (Japan); Kim, Chanhyoun [University of Tokyo, Graduate School of Arts and Sciences (Japan); Higaki, Hiroyuki [Hiroshima University, Graduate School of Advanced Science of Matter (Japan); Nagata, Yugo; Kanai, Yasuyuki [RIKEN Advanced Science Institute (Japan); Torii, Hiroyuki A. [University of Tokyo, Graduate School of Arts and Sciences (Japan); Corradini, Maurizzio; Leali, Marco; Lodi-Rizzini, Evandro; Mascagna, Valerio; Venturelli, Luca; Zurlo, Nicola [Universita di Brescia and Instituto Nazionale di Fisica Nucleare, Dipartimento di Chimica e Fisica per l' Ingegneria e per i Materiali (Italy); Fujii, Koki; Ohtsuka, Miki; Tanaka, Kazuo [University of Tokyo, Graduate School of Arts and Sciences (Japan); Imao, Hiroshi [RIKEN Nishina Center for Accelerator-Based Science (Japan); Nagashima, Yasuyuki [Tokyo University of Science, Department of Physics (Japan); Matsuda, Yasuyuki [University of Tokyo, Graduate School of Arts and Sciences (Japan); and others

2012-05-15

ASACUSA collaboration has been making a path to realize high precision microwave spectroscopy of ground-state hyperfine transitions of antihydrogen atom in flight for stringent test of the CPT symmetry. Recently, we have succeeded in synthesizing our first cold antihydrogen atoms employing a CUSP trap. It is expected that synthesized antihydrogen atoms in the low-field-seeking states are preferentially focused along the cusp magnetic field axis whereas those in the high-field-seeking states are not focused, resulting in the formation of a spin-polarized antihydrogen beam. We report the recent results of antihydrogen atom synthesis and beam production developed with the CUSP trap.

Synthesis of antihydrogen atoms in a CUSP trap

International Nuclear Information System (INIS)

Kuroda, Naofumi; Enomoto, Yoshinori; Michishio, Koji; Kim, Chanhyoun; Higaki, Hiroyuki; Nagata, Yugo; Kanai, Yasuyuki; Torii, Hiroyuki A.; Corradini, Maurizzio; Leali, Marco; Lodi-Rizzini, Evandro; Mascagna, Valerio; Venturelli, Luca; Zurlo, Nicola; Fujii, Koki; Ohtsuka, Miki; Tanaka, Kazuo; Imao, Hiroshi; Nagashima, Yasuyuki; Matsuda, Yasuyuki

2012-01-01

ASACUSA collaboration has been making a path to realize high precision microwave spectroscopy of ground-state hyperfine transitions of antihydrogen atom in flight for stringent test of the CPT symmetry. Recently, we have succeeded in synthesizing our first cold antihydrogen atoms employing a CUSP trap. It is expected that synthesized antihydrogen atoms in the low-field-seeking states are preferentially focused along the cusp magnetic field axis whereas those in the high-field-seeking states are not focused, resulting in the formation of a spin-polarized antihydrogen beam. We report the recent results of antihydrogen atom synthesis and beam production developed with the CUSP trap.

Detecting atheromatous plaques in the aortic arch or supra-aortic arteries for more accurate stroke subtype classification.

Science.gov (United States)

Cui, Xiaoyang; Wu, Simiao; Zeng, Quantao; Xiao, Jiahe; Liu, Ming

2015-02-01

To investigate the correlations of atheromatous plaques in the aortic arch or supra-aortic arteries with intracranial arterial stenosis and carotid plaques in stroke patients, and to determine whether taking these plaques into account will reduce the proportion of patients in the undetermined etiology group. We prospectively enrolled 308 ischemic stroke patients, whose clinical characteristics and A-S-C-O classifications were compared with analyses of intracranial arteries, carotid arteries, aortic arch, and supra-aortic arteries. 125(40.6%) patients had plaques in the aortic arch or supra-aortic arteries, of which 106 (84.8%) had complex plaques. No correlations were observed between these plaques and carotid plaques ( p = 0.283) or intracranial arterial stenosis ( p = 0.097). After detecting the mobile thrombi in the aortic arch and supra-aortic arteries, the proportion of patients in the atherothrombosis group was increased from 33.8% to 55.5% ( p = 0.00), whereas the proportion of patients in stroke of undetermined etiology group was decreased from 19.2% to 11.0% ( p = 0.00). Examining only the carotid and intracranial arteries may not provide adequate information about large arteries in stroke patients. Therefore, it would be better to include a search for relevant plaques in the aortic arch or supra-aortic arteries in modern stroke workup, for it may lead to more accurate stroke subtype classification and guide secondary prevention.

Dynamics of Triaxial Elliptical Galaxies with Cusps

Science.gov (United States)

Fridman, Tema

1997-06-01

The gravitational potentials, orbital properties, and self-consistent equilibria of triaxial stellar systems with central density cusps are examined. Observations of the nuclei of early-type galaxies with the Hubble Space Telescope (HST) suggest that their surface brightness profiles fall into two categories: the 'cores' and the 'power laws.' We show that this dichotomy results from an optical illusion associated with projection onto the plane of the sky. Galaxies of both types have deprojected density profiles that are well-described as power-laws at small radii, with slopes 0≤γ 0.8. Regular box orbits, which depend for their existence on the stability of the long-axis orbit, do not exist in these models. The next-lowest resonance, the 2: 1 banana family, is present whenever the long-axis orbit is unstable. However the banana orbits have a very restricted range of shapes and are thicker than the model isodensity surfaces when c/a/ ~self-consistent models of triaxial galaxies with Dehnen's (1993) density law. We consider central density cusps defined by γ = 1 (weak cusp) and γ = 2 (strong cusp). These values are representative of the nuclear density profiles of bright ('core') and faint ('power-law') galaxies as observed with HST. Both mass models have short-to-long axis ratios of 1:2 and are maximally triaxial. We compute libraries of ~7000 orbits in each of the models and map them as a function of energy. A large fraction of the orbits in both model potentials are stochastic, which diffuse relatively quickly through their allowed phase-space in the strong-cusp potential (~103 dynamical times) and more slowly in the weak-cusp potential (104 dynamical times or longer). Attempts to construct self-consistent solutions using just the regular orbits failed for both mass models. Quasi-equilibrium solutions that include the stochastic orbits exist for both models; however, real galaxies constructed in this way would evolve near the center due to the continued

3D printed abdominal aortic aneurysm phantom for image guided surgical planning with a patient specific fenestrated endovascular graft system

Science.gov (United States)

Meess, Karen M.; Izzo, Richard L.; Dryjski, Maciej L.; Curl, Richard E.; Harris, Linda M.; Springer, Michael; Siddiqui, Adnan H.; Rudin, Stephen; Ionita, Ciprian N.

2017-03-01

Following new trends in precision medicine, Juxatarenal Abdominal Aortic Aneurysm (JAAA) treatment has been enabled by using patient-specific fenestrated endovascular grafts. The X-ray guided procedure requires precise orientation of multiple modular endografts within the arteries confirmed via radiopaque markers. Patient-specific 3D printed phantoms could familiarize physicians with complex procedures and new devices in a risk-free simulation environment to avoid periprocedural complications and improve training. Using the Vascular Modeling Toolkit (VMTK), 3D Data from a CTA imaging of a patient scheduled for Fenestrated EndoVascular Aortic Repair (FEVAR) was segmented to isolate the aortic lumen, thrombus, and calcifications. A stereolithographic mesh (STL) was generated and then modified in Autodesk MeshMixer for fabrication via a Stratasys Eden 260 printer in a flexible photopolymer to simulate arterial compliance. Fluoroscopic guided simulation of the patient-specific FEVAR procedure was performed by interventionists using all demonstration endografts and accessory devices. Analysis compared treatment strategy between the planned procedure, the simulation procedure, and the patient procedure using a derived scoring scheme. Results: With training on the patient-specific 3D printed AAA phantom, the clinical team optimized their procedural strategy. Anatomical landmarks and all devices were visible under x-ray during the simulation mimicking the clinical environment. The actual patient procedure went without complications. Conclusions: With advances in 3D printing, fabrication of patient specific AAA phantoms is possible. Simulation with 3D printed phantoms shows potential to inform clinical interventional procedures in addition to CTA diagnostic imaging.

The left ventricle in aortic stenosis--imaging assessment and clinical implications.

Science.gov (United States)

Călin, Andreea; Roşca, Monica; Beladan, Carmen Cristiana; Enache, Roxana; Mateescu, Anca Doina; Ginghină, Carmen; Popescu, Bogdan Alexandru

2015-04-29

Aortic stenosis has an increasing prevalence in the context of aging population. In these patients non-invasive imaging allows not only the grading of valve stenosis severity, but also the assessment of left ventricular function. These two goals play a key role in clinical decision-making. Although left ventricular ejection fraction is currently the only left ventricular function parameter that guides intervention, current imaging techniques are able to detect early changes in LV structure and function even in asymptomatic patients with significant aortic stenosis and preserved ejection fraction. Moreover, new imaging parameters emerged as predictors of disease progression in patients with aortic stenosis. Although proper standardization and confirmatory data from large prospective studies are needed, these novel parameters have the potential of becoming useful tools in guiding intervention in asymptomatic patients with aortic stenosis and stratify risk in symptomatic patients undergoing aortic valve replacement.This review focuses on the mechanisms of transition from compensatory left ventricular hypertrophy to left ventricular dysfunction and heart failure in aortic stenosis and the role of non-invasive imaging assessment of the left ventricular geometry and function in these patients.

Neurocardiogenic Syncope and Supraventricular Tachycardia in Association with a Rare Congenital Aortic Valve Abnormality

Directory of Open Access Journals (Sweden)

Yashwant Agrawal

2016-01-01

Full Text Available We report a case of a 26-year-old woman who presented with multiple episodes of syncope over a five-months period of time. Transthoracic echocardiogram had shown a normal functioning quadricuspid aortic valve (QAV which was also confirmed on a transesophageal echocardiogram. Computed tomographic angiography of heart and coronary arteries showed the QAV with equal size of all aortic cusps and normal coronary arteries. Intermittent chest pain and palpitations warranted an exercise stress test. The stress test revealed normal aerobic exertion, with achievement of 101% of maximal peak heart rate. However, during peak stress, we noted a drop in her blood pressure significantly resulting in dizziness. No arrhythmias were noted during the stress test. With recurrent syncope episodes and palpitations, Holter monitoring was done, revealing supraventricular tachycardia (SVT. We discuss current available literature and coassociations with QAV. New association of QAV with SVT needs further analysis.

Opening the cusp. [using magnetic field topology

Science.gov (United States)

Crooker, N. U.; Toffoletto, F. R.; Gussenhoven, M. S.

1991-01-01

This paper discusses the magnetic field topology (determined by the superposition of dipole, image, and uniform fields) for mapping the cusp to the ionosphere. The model results are compared to both new and published observations and are then used to map the footprint of a flux transfer event caused by a time variation in the merging rate. It is shown that the cusp geometry distorts the field lines mapped from the magnetopause to yield footprints with dawn and dusk protrusions into the region of closed magnetic flux.

Bentall operation for a child with Marfan syndrome: a case report.

Science.gov (United States)

Miura, M; Shimazaki, Y; Watanabe, T; Iijima, Y; Kuraoka, S; Inui, K; Oshikirl, T; Uchida, T; Nakasato, M

1997-01-01

Children with Marfan syndrome rarely undergo surgery for annuloaortic ectasia and aortic regurgitation in the first decade. A 7-year-old girl presented with congestive heart failure due to severe aortic regurgitation associated with annuloaortic ectasia (6 cm). She also had funnel chest. She underwent a Bentall operation and sternal turn-over with a satisfactory result. Since the aortic valve cusps had rolled edges, the aortic valve was not spared. Histology of the aortic valve cusps showed myxoid degeneration and fragmentation of elastic fibers.

Some low-altitude cusp dependencies on the interplanetary magnetic field

International Nuclear Information System (INIS)

Newell, P.T.; Meng, C.; Sibeck, D.G.; Lepping, R.

1989-01-01

Although it has become well established that the low-altitude polar cusp moves equatorward during intervals of southward interplanetary magnetic field (IMF B z y negative (positive) in the northern (southern) hemisphere and postnoon for B y positive (negative) in the northern (southern) hemisphere. The B y induced shift is much more pronounced for southward than for northward B z , a result that appears to be consistent with elementary considerations from, for example, the antiparallel merging model. No interhemispherical latitudinal differences in cusp positions were found that could be attributed to the IMF B x component. As expected, the cusp latitudinal position correlated reasonably well (0.70) with B z when the IMF had a southward component; the previously much less investigated correlation for B z northward proved to be only 0.18, suggestive of a half-wave rectifier effect. The ratio of cusp ion number flux precipitation for B z southward to that for B z northward was 1.75±0.12. The statistical local time (full) width of the cusp proper was found to be 2.1 hours for B z northward and 2.8 hours for B z southward. copyright American Geophysical Union 1989

DISSECT: a new mnemonic-based approach to the categorization of aortic dissection.

Science.gov (United States)

Dake, M D; Thompson, M; van Sambeek, M; Vermassen, F; Morales, J P

2013-08-01

Classification systems for aortic dissection provide important guides to clinical decision-making, but the relevance of traditional categorization schemes is being questioned in an era when endovascular techniques are assuming a growing role in the management of this frequently complex and catastrophic entity. In recognition of the expanding range of interventional therapies now used as alternatives to conventional treatment approaches, the Working Group on Aortic Diseases of the DEFINE Project developed a categorization system that features the specific anatomic and clinical manifestations of the disease process that are most relevant to contemporary decision-making. The DISSECT classification system is a mnemonic-based approach to the evaluation of aortic dissection. It guides clinicians through an assessment of six critical characteristics that facilitate optimal communication of the most salient details that currently influence the selection of a therapeutic option, including those findings that are key when considering an endovascular procedure, but are not taken into account by the DeBakey or Stanford categorization schemes. The six features of aortic dissection include: duration of disease; intimal tear location; size of the dissected aorta; segmental extent of aortic involvement; clinical complications of the dissection, and thrombus within the aortic false lumen. In current clinical practice, endovascular therapy is increasingly considered as an alternative to medical management or open surgical repair in select cases of type B aortic dissection. Currently, endovascular aortic repair is not used for patients with type A aortic dissection, but catheter-based techniques directed at peripheral branch vessel ischemia that may complicate type A dissection are considered valuable adjunctive interventions, when indicated. The use of a new system for categorization of aortic dissection, DISSECT, addresses the shortcomings of well-known established schemes devised

Reimplantation valve-sparing aortic root replacement in Marfan syndrome using the Valsalva conduit: an intercontinental multicenter study.

Science.gov (United States)

Settepani, Fabrizio; Szeto, Wilson Y; Pacini, Davide; De Paulis, Ruggero; Chiariello, Luigi; Di Bartolomeo, Roberto; Gallotti, Roberto; Bavaria, Joseph E

2007-02-01

Introduced by DePaulis in 2000, the Gelweave Valsalva graft (Sulzer Vascutek, Refrewshire, Scotland) is a modified Dacron conduit (DuPont, Wilmington, DE), with prefashioned sinuses of Valsalva. The aim of this study was to evaluate the mid-term results of the reimplantation valve-sparing aortic root replacement using the Gelweave Valsalva prosthesis in Marfan syndrome patients. A retrospective review was performed of 35 patients with Marfan syndrome in four centers who underwent the reimplantation valve-sparing aortic root replacement using the Gelweave Valsalva prosthesis. The patients were predominantly men, with a mean age of 36.5 +/- 12.6 years (range, 14 to 62 years). Two patients presented with acute type A dissections and underwent emergent operations. Elective hemiarch reconstruction using hypothermic circulatory arrest was required in 11 patients. Aortic valve cusp repair was performed in 2 patients. There were no operative or hospital deaths, and no patients died during follow-up. The mean follow-up was 19 months (range, 1 to 60 months). Significant (>2+) aortic insufficiency (AI), requiring aortic valve replacement, developed in 3 patients during follow-up that requiring aortic valve replacement. The 5-year freedom from reoperation owing to structural valve deterioration was 88.9% +/- 8.1%. There were no episodes of clinically significant thromboembolism. Reimplantation valve-sparing aortic root replacement with the Gelweave Valsalva prosthesis in Marfan patients provides satisfactory mid-term results, thus encouraging further use of this type of repair. However, long-term results are needed in order to define the durability of this technique.

Optimal C-arm angulation during transcatheter aortic valve replacement: Accuracy of a rotational C-arm computed tomography based three dimensional heart model.

Science.gov (United States)

Veulemans, Verena; Mollus, Sabine; Saalbach, Axel; Pietsch, Max; Hellhammer, Katharina; Zeus, Tobias; Westenfeld, Ralf; Weese, Jürgen; Kelm, Malte; Balzer, Jan

2016-10-26

To investigate the accuracy of a rotational C-arm CT-based 3D heart model to predict an optimal C-arm configuration during transcatheter aortic valve replacement (TAVR). Rotational C-arm CT (RCT) under rapid ventricular pacing was performed in 57 consecutive patients with severe aortic stenosis as part of the pre-procedural cardiac catheterization. With prototype software each RCT data set was segmented using a 3D heart model. From that the line of perpendicularity curve was obtained that generates a perpendicular view of the aortic annulus according to the right-cusp rule. To evaluate the accuracy of a model-based overlay we compared model- and expert-derived aortic root diameters. For all 57 patients in the RCT cohort diameter measurements were obtained from two independent operators and were compared to the model-based measurements. The inter-observer variability was measured to be in the range of 0°-12.96° of angular C-arm displacement for two independent operators. The model-to-operator agreement was 0°-13.82°. The model-based and expert measurements of aortic root diameters evaluated at the aortic annulus ( r = 0.79, P optimal C-arm configuration, potentially simplifying current clinical workflows before and during TAVR.

Cusp singularities in f(R) gravity: pros and cons

International Nuclear Information System (INIS)

Chen, Pisin; Yeom, Dong-han

2015-01-01

We investigate cusp singularities in f(R) gravity, especially for Starobinsky and Hu-Sawicki dark energy models. We illustrate that, by using double-null numerical simulations, a cusp singularity can be triggered by gravitational collapses. This singularity can be cured by adding a quadratic term, but this causes a Ricci scalar bump that can be observed by an observer outside the event horizon. Comparing with cosmological parameters, it seems that it would be difficult to see super-Planckian effects by astrophysical experiments. On the other hand, at once there exists a cusp singularity, it can be a mechanism to realize a horizon scale curvature singularity that can be interpreted by a firewall

Rip Currents, Mega-Cusps, and Eroding Dunes

OpenAIRE

Thornton, E.B.; MacMahan, J.; Sallenger, A.H.

2006-01-01

Submitted to Marine Geology 1 November 2006 Dune erosion is shown to occur at the embayment of beach mega-cusps O(200m alongshore) that are associated with rip currents. The beach is the narrowest at the embayment of the mega-cusps allowing the swash of large storm waves coincident with high tides to reach the toe of the dune, to undercut the dune and to cause dune erosion. Field measurements of dune, beach, and rip current morphology are acquired along an 18 km shoreline in southern Mont...

ULF Narrowband Emissions Analysis in the Terrestrial Polar Cusps

Science.gov (United States)

Grison, B.; Pisa, D.

2013-05-01

Polar cusps are known to be a key region for transfer of mass and momentum between the adjacent magnetosheath and the magnetosphere. The 4 spacecraft of the Cluster ESA mission crossed the polar cusps in their most distant part to the Earth in the early years of the mission (2000-2004) because of their highly eccentric orbit. The ULF wave activity in the cusp region has been linked with the magnetosheath plasma penetration since HEOS observations (D'Angelo et al., 1974). Wave and particle interaction play an important role in this colisionless plasma. The observed wave activity certainly results from both distant and local generation mechanisms. From Cluster case studies we propose to focus on one aspect for each of this place of generation. Concerning the distant generation, the possibility of a wave generation at the magnetopause itself is investigated. For this purpose we compare the propagation of the emissions on each side of the magnetopasue, i.e. in the cusp and in the magnetosheath. Concerning the local generation, the presence of locally generated waves above the local proton gyrofrequency that display a left hand polarization has been reported in Polar and Cluster studies (Le et al., 2001; Nykyri et al., 2003 ). The Doppler shift was not large enough to explain the observed frequency. We propose here to combine various techniques (k-filtering analysis, WHAMP simulations) to achieve a precise wave vector estimation and to explain these observations. References: D'Angelo, N., A. Bahnsen, and H. Rosenbauer (1974), Wave and particle measurements at the polar cusp, J. Geophys. Res., 79( 22), 3129-3134, doi:10.1029/JA079i022p03129. Le, G., X. Blanco-Cano, C. T. Russell, X.-W. Zhou, F. Mozer, K. J. Trattner, S. A. Fuselier, and B. J. Anderson (2001), Electromagnetic ion cyclotron waves in the high-altitude cusp: Polar observations, J. Geophys. Res., 106(A9), 19067-19079, doi:10.1029/2000JA900163. Nykyri, K., P. J. Cargill, E. A. Lucek, T. S. Horbury, A. Balogh

Valve-sparing root replacement in children with aortic root aneurysm: mid-term results.

Science.gov (United States)

Lange, Rüdiger; Badiu, Catalin C; Vogt, Manfred; Voss, Bernhard; Hörer, Jürgen; Prodan, Zsolt; Schreiber, Christian; Mazzitelli, Domenico

2013-05-01

We aimed at evaluating the results of aortic valve-sparing root replacement (AVSRR) in children with aortic root aneurysm (ARA) due to genetic disorders in terms of mortality, reoperation and recurrent aortic valve regurgitation (AVR). Thirteen patients (mean age 9.7 ± 6.5 years, 10 months-18 years) underwent AVSRR for ARA between 2002 and 2011. Six of the 13 patients had Marfan syndrome, 3 Loeys-Dietz syndrome (LDS), 2 bicuspid aortic valve syndrome and 2 an unspecified connective tissue disorder. AVR was graded as none/trace, mild and severe in 5, 7 and 1 patient, respectively. The mean pre-operative root diameter was 45 ± 10 mm (mean Z-score 10.3 ± 2.0). Remodelling of the aortic root was performed in 4 patients, reimplantation of the aortic valve in 9 and a concomitant cusp repair in 4. The diameter of the prostheses used for root replacement varied from 22 to 30 mm (mean Z-score = 2.3 ± 3). The follow-up was 100% complete with a mean follow-up time of 3.7 years. There was no operative mortality. One patient with LDS died 2.5 years after the operation due to spontaneous rupture of the descending aorta. Root re-replacement with mechanical conduit was necessary in 1 patient for severe recurrent AVR 8 days after remodelling of the aortic root. At final follow-up, AVR was graded as none/trace and mild in all patients. Eleven patients presented in New York Heart Association functional Class I and 1 in Class II. In paediatric patients with ARA, valve-sparing root replacement can be performed with low operative risk and excellent mid-term valve durability. Hence, prosthetic valve-related morbidity may be avoided. Due to the large diameters of the aortic root and the ascending aorta, the size of the implanted root prostheses will not limit later growth of the native aorta.

Rip currents, mega-cusps, and eroding dunes

Science.gov (United States)

Thornton, E.B.; MacMahan, J.; Sallenger, A.H.

2007-01-01

Dune erosion is shown to occur at the embayment of beach mega-cusps O(200 m alongshore) that are associated with rip currents. The beach is the narrowest at the embayment of the mega-cusps allowing the swash of large storm waves coincident with high tides to reach the toe of the dune, to undercut the dune and to cause dune erosion. Field measurements of dune, beach, and rip current morphology are acquired along an 18 km shoreline in southern Monterey Bay, California. This section of the bay consists of a sandy shoreline backed by extensive dunes, rising to heights exceeding 40 m. There is a large increase in wave height going from small wave heights in the shadow of a headland, to the center of the bay where convergence of waves owing to refraction over the Monterey Bay submarine canyon results in larger wave heights. The large alongshore gradient in wave height results in a concomitant alongshore gradient in morphodynamic scale. The strongly refracted waves and narrow bay aperture result in near normal wave incidence, resulting in well-developed, persistent rip currents along the entire shoreline. The alongshore variations of the cuspate shoreline are found significantly correlated with the alongshore variations in rip spacing at 95% confidence. The alongshore variations of the volume of dune erosion are found significantly correlated with alongshore variations of the cuspate shoreline at 95% confidence. Therefore, it is concluded the mega-cusps are associated with rip currents and that the location of dune erosion is associated with the embayment of the mega-cusp.

Enamel microstructure and microstrain in the fracture of human and pig molar cusps.

Science.gov (United States)

Popowics, T E; Rensberger, J M; Herring, S W

2004-08-01

The role of microstructure in enamel strain and breakage was investigated in human molar cusps and those of the pig, Sus scrofa. Rosette strain gauges were affixed to cusp surfaces (buccal human M3, n=15, and lingual pig M1, n=13), and a compressive load was applied to individual cusps using an MTS materials testing machine. Load and strain data were recorded simultaneously until cusp fracture, and these data were used to estimate enamel stresses, principal strains, and stiffness. Fractured and polished enamel fragments were examined in multiple planes using scanning electron microscopy (SEM). Human cusp enamel showed greater stiffness than pig enamel (P=0.02), and tensile stress at yield was higher (17.9 N/mm2 in humans versus 8.9 N/mm2 in pigs, P=0.06). SEM revealed enamel rod decussation in both human and pig enamel; however, only pig enamel showed a decussation plane between rod and inter-rod crystallites. Human inter-rod enamel was densely packed between rods, whereas in pig enamel, inter-rod enamel formed partitions between rows of enamel rods. Overall, human enamel structure enabled molar cusps to withstand horizontal tensile stress during both elastic and plastic phases of compressive loading. In contrast, pig cusp enamel was less resistant to horizontal tensile stresses, but appeared to fortify the enamel against crack propagation in multiple directions. These structural and biomechanical differences in cusp enamel are likely to reflect species-level differences in occlusal function.

A general three-dimensional parametric geometry of the native aortic valve and root for biomechanical modeling.

Science.gov (United States)

Haj-Ali, Rami; Marom, Gil; Ben Zekry, Sagit; Rosenfeld, Moshe; Raanani, Ehud

2012-09-21

The complex three-dimensional (3D) geometry of the native tricuspid aortic valve (AV) is represented by select parametric curves allowing for a general construction and representation of the 3D-AV structure including the cusps, commissures and sinuses. The proposed general mathematical description is performed by using three independent parametric curves, two for the cusp and one for the sinuses. These curves are used to generate different surfaces that form the structure of the AV. Additional dependent curves are also generated and utilized in this process, such as the joint curve between the cusps and the sinuses. The model's feasibility to generate patient-specific parametric geometry is examined against 3D-transesophageal echocardiogram (3D-TEE) measurements from a non-pathological AV. Computational finite-element (FE) mesh can then be easily constructed from these surfaces. Examples are given for constructing several 3D-AV geometries by estimating the needed parameters from echocardiographic measurements. The average distance (error) between the calculated geometry and the 3D-TEE measurements was only 0.78±0.63mm. The proposed general 3D parametric method is very effective in quantitatively representing a wide range of native AV structures, with and without pathology. It can also facilitate a methodical quantitative investigation over the effect of pathology and mechanical loading on these major AV parameters. Copyright © 2012 Elsevier Ltd. All rights reserved.

In vitro fracture resistance of fiber reinforced cusp-replacing composite restorations.

NARCIS (Netherlands)

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

2005-01-01

OBJECTIVES: To assess the fracture resistance and failure mode of fiber reinforced composite (FRC) cusp-replacing restorations in premolars. METHODS: Forty-five extracted sound upper premolars were randomly divided into three groups. Identical MOD cavities with simulated buccal cusp fracture and

Low pressure hugoniot cusp in polymeric materials

Science.gov (United States)

Sheffield, S. A.; Bloomquist, D. D.

1982-04-01

It has previously been shown that polymethyl methacrylate (PMMA) exhibits a cusp in the shock Hugoniot at about 2.0 GPa which corresponds with the beginning of shock-induced polarization and the beginning of an exothermic reaction measured in thermocouple and resistivity gauge temperature studies. We now report results we have recently obtained from an ongoing study which indicate that other polymers have similar behavior at about the same pressure. Quartz gauge impact experiments have been performed using polypyro-ellitimide (Vespel) and polysulfone impactors to obtain Hugoniot information and the stress history at the impact plane. In the case of Vespel a slight Hugoniot cusp was observed at about 1.8 GPa which coincides with the start of shock-induced polarization. Polysulfone does not appear to have a cusp but does show stress relaxation at the impact plane beginning at about 1.8 GPa, again coinciding with the start of shock-induced polarization. It has been suggested earlier that the abnormal behavior in PMMA is the result of a shock-induced chemical reaction. This new information suggests that a stress of about 2 GPa is a threshold for shock-induced chemical reaction in several polymers.

Cluster observations of ion dispersion discontinuities in the polar cusp

Science.gov (United States)

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

2009-12-01

The reconnection between the interplanetary magnetic field (IMF) and the Earth’s magnetic field is taking place at the magnetopause on magnetic field lines threading through the polar cusp. When the IMF is southward, reconnection occurs near the subsolar point, which is magnetically connected to the equatorward boundary of the polar cusp. Subsequently the ions injected through the reconnection point precipitate in the cusp and are dispersed poleward. If reconnection is continuous and operates at constant rate, the ion dispersion is smooth and continuous. On the other hand if the reconnection rate varies, we expect interruption in the dispersion forming energy steps or staircase. Similarly, multiple entries near the magnetopause could also produce steps at low or mid-altitude when a spacecraft is crossing subsequently the field lines originating from these multiple sources. In addition, motion of the magnetopause induced by solar wind pressure changes or erosion due to reconnection can also induce a motion of the polar cusp and a disruption of the ions dispersion observed by a spacecraft. Cluster with four spacecraft following each other in the mid-altitude cusp can be used to distinguish between these “temporal” and “spatial” effects. We will present a cusp crossing with two spacecraft, separated by around two minutes. The two spacecraft observed a very similar dispersion with a step in energy in its centre and two other dispersions poleward. We will show that the steps could be temporal (assuming that the time between two reconnection bursts corresponds to the time delay between the two spacecraft) but it would be a fortuitous coincidence. On the other hand the steps and the two poleward dispersions could be explained by spatial effects if we take into account the motion of the open-closed boundary between the two spacecraft crossings.

Cluster Observations of Ion Dispersions near the Exterior Cusp

Science.gov (United States)

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

2013-12-01

The cusps are the places where the Earth's magnetic field lines, connected to the inner side of the magnetopause, converge. It is therefore the place where signatures of processes occurring near the subsolar point, in the tail lobes, as well as near the dawn and dusk flanks are observed. The main process that injects solar wind plasma into the polar cusp is now generally accepted to be magnetic reconnection. Depending on the IMF direction, this process will take place equatorward (for IMF southward), poleward (for IMF northward) or on the side (for IMF azimuthal) of the cusp. We report a Cluster crossing on 5 January 2002 near the exterior cusp on the southern dusk side. The IMF was mainly azimuthal (IMF-By around -5 nT), the solar wind speed around 280 km/s and the density around 5 cm-3. The four Cluster spacecraft were still in the "magnetotail" configuration with two perfect tetrahedra of 2000 km around apogee and turning into an elongated configuration near the magnetopause. C4 was the first spacecraft to enter the cusp around 19:52:04 UT, followed by C2 at 19:52:35 UT, C1 at 19:54:24 UT and C3 at 20:13:15 UT. C4 and C1 observed two ion energy dispersions at 20:10 UT and 20:40 UT and C3 at 20:35 UT and 21:15 UT. We will investigate the origin of the injections forming the dispersions and if these can be explained by the reconnection between the interplanetary magnetic field and the Earth's magnetic field.

Resurgence of the Cusp Anomalous Dimension

International Nuclear Information System (INIS)

Dorigoni, Daniele; Hatsuda, Yasuyuki

2015-06-01

We revisit the strong coupling limit of the cusp anomalous dimension in planar N=4 super Yang-Mills theory. It is known that the strong coupling expansion is asymptotic and non-Borel summable. As a consequence, the cusp anomalous dimension receives non-perturbative corrections, and the complete strong coupling expansion should be a resurgent transseries. We reveal that the perturbative and non-perturbative parts in the transseries are closely interrelated. Solving the Beisert-Eden-Staudacher equation systematically, we analyze in detail the large order behavior in the strong coupling perturbative expansion and show that the non-perturbative information is indeed encoded there. An ambiguity of (lateral) Borel resummations of the perturbative expansion is precisely canceled by the contributions from the non-perturbative sectors, and the final result is real and unambiguous.

Resurgence of the cusp anomalous dimension

Energy Technology Data Exchange (ETDEWEB)

Dorigoni, Daniele; Hatsuda, Yasuyuki [DESY Theory Group, DESY Hamburg,Notkestrasse 85, D-22603 Hamburg (Germany)

2015-09-21

We revisit the strong coupling limit of the cusp anomalous dimension in planar N=4 super Yang-Mills theory. It is known that the strong coupling expansion is asymptotic and non-Borel summable. As a consequence, the cusp anomalous dimension receives non-perturbative corrections, and the complete strong coupling expansion should be a resurgent transseries. We reveal that the perturbative and non-perturbative parts in the transseries are closely interrelated. Solving the Beisert-Eden-Staudacher equation systematically, we analyze in detail the large order behavior in the strong coupling perturbative expansion and show that the non-perturbative information is indeed encoded there. An ambiguity of (lateral) Borel resummations of the perturbative expansion is precisely canceled by the contributions from the non-perturbative sectors, and the final result is real and unambiguous.

Resurgence of the Cusp Anomalous Dimension

Energy Technology Data Exchange (ETDEWEB)

Dorigoni, Daniele; Hatsuda, Yasuyuki [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group

2015-06-15

We revisit the strong coupling limit of the cusp anomalous dimension in planar N=4 super Yang-Mills theory. It is known that the strong coupling expansion is asymptotic and non-Borel summable. As a consequence, the cusp anomalous dimension receives non-perturbative corrections, and the complete strong coupling expansion should be a resurgent transseries. We reveal that the perturbative and non-perturbative parts in the transseries are closely interrelated. Solving the Beisert-Eden-Staudacher equation systematically, we analyze in detail the large order behavior in the strong coupling perturbative expansion and show that the non-perturbative information is indeed encoded there. An ambiguity of (lateral) Borel resummations of the perturbative expansion is precisely canceled by the contributions from the non-perturbative sectors, and the final result is real and unambiguous.

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.

1999-01-01

, respectively, with magnitudes of around 0.5 A/km(2). The geometry of the current system resembles a DPY current system [Friis-Christensen and Wilhjelm, 1975]. Using our results, we test alternative theories on cusp current origin that lead to different predictions of the relative location of the cusp current...... 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....... 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...

Maass Cusp Forms on Singly Punctured Two-Torus

International Nuclear Information System (INIS)

Siddig, Abubaker Ahmed Mohamed; Shah, Nurisya Mohd; Zainuddin, Hishamuddin

2009-01-01

Quantum mechanical systems on punctured surfaces modeled by hyperbolic spaces can play an interesting role in exploring quantum chaos and in studying behaviour of future quantum nano-devices. The case of singly-punctured two-torus, for example, has been well-studied in the literature particularly for its scattering states. However, the bound states on the punctured torus given by Maass cusp forms are lesser known. In this note, we report on the algorithm of numerically computing these functions and we present ten lower-lying eigenvalues for each odd and even Maass cusp forms.

The role of annular dimension and annuloplasty in tricuspid aortic valve repair.

Science.gov (United States)

de Kerchove, Laurent; Mastrobuoni, Stefano; Boodhwani, Munir; Astarci, Parla; Rubay, Jean; Poncelet, Alain; Vanoverschelde, Jean-Louis; Noirhomme, Philippe; El Khoury, Gebrine

2016-02-01

Valve sparing reimplantation can improve the durability of bicuspid aortic valve repair compared with subcommissural annuloplasty, especially in patients with a large basal ring. This study analyses the effect of basal ring size and annuloplasty on valve repair in the setting of a tricuspid aortic valve. From 1995 to 2013, 382 patients underwent elective tricuspid aortic valve repair. We included only those undergoing subcommissural annuloplasty, valve sparing reimplantation or no annuloplasty and in whom intraoperative transoesophageal echocardiography images were available for retrospective pre- and post-repair basal ring measurements (n = 323, subcommissural annuloplasty: 146, valve sparing reimplantation: 154, no annuloplasty: 23). In a subgroup of patients with available echocardiographic images, basal ring was retrospectively measured at the latest follow-up or prior to reoperation. subcommissural annuloplasty and valve sparing reimplantation were compared after matching for degree of aortic regurgitation and root size. All three groups differed significantly for most of preoperative characteristics. Hospital mortality was 0.9%. The median follow-up was 4.7 years. At 8 years, overall survival was 80 ± 5%. Freedom from reoperation and freedom from aortic regurgitation >1+ were 92 ± 5% and 71 ± 8%, respectively. In multivariate analysis, predictors of aortic regurgitation >1+ were left ventricular end-diastolic diameter (P = 0.003), cusp repair (P = 0.006), body surface area (P = 0.01) and subcommissural annuloplasty (P = 0.05). In subcommissural annuloplasty, freedom from aortic regurgitation >1+ was lower for patients with basal ring ≥28 mm compared with patients with basal ring 1+ was independent of basal ring size (P = 0.38). In matched comparison between subcommissural annuloplasty and valve sparing reimplantation, freedom from aortic regurgitation >1+ was not significantly different (P = 0.06), but in patients with basal ring ≥28 mm, valve sparing

On a new process for cusp irregularity production

Directory of Open Access Journals (Sweden)

H. C. Carlson

2008-09-01

Full Text Available Two plasma instability mechanisms were thought until 2007 to dominate the formation of plasma irregularities in the F region high latitude and polar ionosphere; the gradient-drift driven instability, and the velocity-shear driven instability. The former mechanism was accepted as accounting for plasma structuring in polar cap patches, the latter for plasma structuring in polar cap sun aligned arcs. Recent work has established the need to replace this view of the past two decades with a new patch plasma structuring process (not a new mechanism, whereby shear-driven instabilities first rapidly structure the entering plasma, after which gradient drift instabilities build on these large "seed" irregularities. Correct modeling of cusp and early polar cap patch structuring will not be accomplished without allowing for this compound process. This compound process explains several previously unexplained characteristics of cusp and early polar cap patch irregularities. Here we introduce additional data, coincident in time and space, to extend that work to smaller irregularity scale sizes and relate it to the structured cusp current system.

Cluster Observations of Particle Injections in the Exterior Cusp

Science.gov (United States)

Escoubet, C. P.; Grison, B.; Berchem, J.; Trattner, K. J.; Lavraud, B.; Pitout, F.; Soucek, J.; Richard, R. L.; Laakso, H. E.; Masson, A.; Dunlop, M. W.; Dandouras, I. S.; Reme, H.; Fazakerley, A. N.; Daly, P. W.

2014-12-01

The main process that injects solar wind plasma into the polar cusp is now generally accepted to be magnetic reconnection. Depending on the IMF direction, this process takes place equatorward (for IMF southward), poleward (for IMF northward) or on the dusk or dawn sides (for IMF azimuthal) of the cusp. We report a Cluster crossing on 5 January 2002 near the exterior cusp on the southern dusk side. The IMF was mainly azimuthal (IMF-By around -5 nT), the solar wind speed lower than usual around 280 km/s with the density of order 5 cm-3. The four Cluster spacecraft had an elongated configuration near the magnetopause. C4 was the first spacecraft to enter the cusp around 19:52:04 UT, followed by C2 at 19:52:35 UT, C1 at 19:54:24 UT and C3 at 20:13:15 UT. C4 and C1 observed two ion energy dispersions at 20:10 UT and 20:40 UT and C3 at 20:35 UT and 21:15 UT. Using the time of flight technique on the upgoing and downgoing ions, which leads to energy dispersions, we obtain distances of the ion sources between 14 and 20 RE from the spacecraft. Using Tsyganenko model, we find that these sources are located on the dusk flank, past the terminator. The first injection by C3 is seen at approximately the same time as the 2nd injection on C1 but their sources at the magnetopause were separated by more than 7 RE. This would imply that two distinct sources were active at the same time on the dusk flank of the magnetosphere. In addition, a flow reversal was observed at the magnetopause on C4 which would be an indication that reconnection is taking place near the exterior cusp.

Characterizing nanoscale topography of the aortic heart valve basement membrane for tissue engineering heart valve scaffold design.

Science.gov (United States)

Brody, Sarah; Anilkumar, Thapasimuthu; Liliensiek, Sara; Last, Julie A; Murphy, Christopher J; Pandit, Abhay

2006-02-01

A fully effective prosthetic heart valve has not yet been developed. A successful tissue-engineered valve prosthetic must contain a scaffold that fully supports valve endothelial cell function. Recently, topographic features of scaffolds have been shown to influence the behavior of a variety of cell types and should be considered in rational scaffold design and fabrication. The basement membrane of the aortic valve endothelium provides important parameters for tissue engineering scaffold design. This study presents a quantitative characterization of the topographic features of the native aortic valve endothelial basement membrane; topographical features were measured, and quantitative data were generated using scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and light microscopy. Optimal conditions for basement membrane isolation were established. Histological, immunohistochemical, and TEM analyses following decellularization confirmed basement membrane integrity. SEM and AFM photomicrographs of isolated basement membrane were captured and quantitatively analyzed. The basement membrane of the aortic valve has a rich, felt-like, 3-D nanoscale topography, consisting of pores, fibers, and elevations. All features measured were in the sub-100 nm range. No statistical difference was found between the fibrosal and ventricular surfaces of the cusp. These data provide a rational starting point for the design of extracellular scaffolds with nanoscale topographic features that mimic those found in the native aortic heart valve basement membrane.

Observations of beach cusp evolution using a stationary, shore-based lidar system

Science.gov (United States)

O'Dea, A.; Whitesides, E. T.; Brodie, K.; Spore, N.

2016-12-01

Although beach cusps are common features on beaches around the world, questions still remain regarding the range of conditions in which they form, the initial forcing conditions under which they form, and the erosive or accretionary nature of cusp events. While many prior studies have focused on the formation and morphology of beach cusps, many of these are limited in the spatial extent of observations, in their spatial or temporal resolution, or in the availability of accompanying hydrodynamic data. In this study, beach cusp formation and evolution is investigated using an automated lidar system that provides hourly three-dimensional scans of subaerial beach topography with high spatial resolution ([O(1 cm)]). The stationary lidar scanner is mounted on a 4-m tower located on the crest of a shore-backing dune on an Atlantic Ocean beach near Duck, North Carolina. The device measures a 237°-framescan of the nearshore region over a 15 minute period each hour. Individual scans are coregistered to a baseline scan using an iterative closest point (ICP) algorithm and then filtered to remove noise, dune vegetation, and water. To assess the accuracy of the coregistration algorithm, the 3-dimensional location of five permanent reflectors near the device are found for each scan and compared to their measured GPS location. Precisely coregistered scans allow for an assessment of elevation change across cuspate features in addition to traditional measurements of cusp wavelength. Beach cusp events are assessed over a three month period from September through November 2015. Wave and current data from a cross-shore array of sensors deployed continuously throughout the three month period as well as from two alongshore arrays of ADV sensors deployed from October 13 through November 1 are used to determine the forcing conditions under which the cusps formed and evolved. Funded by the USACE Coastal Field Data Collection Program.

Experimental investigation of plasma sheaths in magnetic mirror and cusp configurations

Science.gov (United States)

Jiang, Zhengqi; Wei, Zi-an; Ma, J. X.

2017-11-01

Sheath structures near a metal plate in a magnetized plasma were experimentally investigated in magnetic mirror and cusp configurations. Plasma parameters and the sheath potential distributions were probed by a planar and an emissive probe, respectively. The measured sheath profiles in the mirror configuration show that the sheath thickness first decreases and then increases when the magnetic strength is raised. A magnetic flux-tube model was used to explain this result. In the cusp configuration, the measured sheath thickness decreases with the increase of the coil current creating the magnetic cusp. However, when normalized by the electron Debye length, the dependence of the sheath thickness on the coil current is reversed.

Percutaneous implantation of the first repositionable aortic valve prosthesis in a patient with severe aortic stenosis.

Science.gov (United States)

Buellesfeld, Lutz; Gerckens, Ulrich; Grube, Eberhard

2008-04-01

Percutaneous aortic valve replacement is a new less-invasive alternative for high-risk surgical candidates with aortic stenosis. However, the clinical experience is still limited, and the currently available 'first-generation devices' revealed technical shortcomings, such as lack of repositionability and presence of paravalvular leakages. We report the first-in-man experience with the new self-expanding Lotus Valve prosthesis composed of a nitinol frame with implemented bovine pericardial leaflets which is designed to address these issues, being repositionable and covered by a flexible membrane to seal paravalvular gaps. We implanted this prosthesis in a 93-year old patient presenting with severe symptomatic aortic stenosis (valve area: 0.6 cm(2)). Surgical valve replacement had been declined due to comorbidities. We used a retrograde approach for insertion of the 21-French Lotus catheter loaded with the valve prosthesis via surgical cut-down to the external iliac artery. Positioning of the valve was guided by transesophageal echo and supra-aortic angiograms. The prosthesis was successfully inserted and deployed within the calcified native valve. Echocardiography immediately after device deployment showed a significant reduction of the transaortic mean pressure gradient (32 to 9 mmHg; final valve area 1.7 cm(2)) without evidence of residual aortic regurgitation. The postprocedural clinical status improved from NYHA-IV to NYHA-II. These results remained unchanged up to the 3 month follow-up. Successful percutaneous aortic valve replacement can be performed using the new self-expanding and repositionable Lotus valve for treatment of high-risk patients with aortic valve stenosis. Further studies are mandatory to assess device safety and efficacy in larger patient populations. Copyright 2008 Wiley-Liss, Inc.

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

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.

Impact of Aortic Insufficiency on Ascending Aortic Dilatation and Adverse Aortic Events After Isolated Aortic Valve Replacement in Patients With a Bicuspid Aortic Valve.

Science.gov (United States)

Wang, Yongshi; Wu, Boting; Li, Jun; Dong, Lili; Wang, Chunsheng; Shu, Xianhong

2016-05-01

Aberrant flow pattern and congenital fragility bestows bicuspid aortic valve (BAV) with a propensity toward ascending aorta dilatation, aneurysm, and dissection. Whether isolated aortic valve replacement (AVR) can prevent further dilatation in BAV ascending aorta and what indicates concurrent aortic intervention in the case of valve operation remain controversial. From June 2006 to January 2009, patients with a BAV who underwent isolated AVR were consecutively included and categorized into aortic insufficiency (BAV-AI, n = 84) and aortic stenosis (n = 112) groups, and another population of patients with a tricuspid aortic valve with aortic insufficiency (n = 149) was also recruited during the same period for comparison of annual aortic dilatation rate and adverse aortic events after isolated AVR. With a median follow-up period of 72 months (interquartile range, 66 to 78 months), ascending aorta dilatation rates were faster in the BAV-AI group than the BAV plus aortic stenosis and tricuspid aortic valve with aortic insufficiency groups (both p regression analysis identified aortic insufficiency (hazard ratio, 3.7; 95% confidence interval, 1.2 to 11.1; p = 0.019) as an independent risk factor for adverse aortic events among patients with BAV in general, whereas preoperative ascending aortic diameter larger than 45 mm (hazard ratio, 13.8; 95% confidence interval, 3.0 to 63.3; p = 0.001) served as a prognostic indicator in the BAV-AI group. An aggressive policy of preventive aortic interventions seemed appropriate in patients with BAV-AI during AVR, and BAV phenotype presenting as either insufficiency or stenosis should be taken into consideration when contemplating optimal surgical strategies for BAV aortopathy. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

ECC cusp analysis

Energy Technology Data Exchange (ETDEWEB)

Pregliasco, R.G. (Centro Atomico Bariloche and CONICET, S.C. de Bariloche (Argentina)); Garibotti, C.R. (Centro Atomico Bariloche and CONICET, S.C. de Bariloche (Argentina)); Barrachina, R. (Centro Atomico Bariloche and CONICET, S.C. de Bariloche (Argentina))

1994-03-01

We measured the ionization double differential cross section for the H[sup +][yields]He 100 keV collision at the proximities of the ECC cusp and all around 0 . We propose an angular function expansion and a procedure for data analysis. We demonstrate that, in this way, the difficulties and shortcomings presented in the standard data processing are overcome. In our experimental results we distinguish the presence of characteristic shapes for the ionization depending on whether the module of the electron velocity is greater or smaller than the projectile velocity. (orig.)

Multi-point observations of Ion Dispersions near the Exterior Cusp with Cluster

Science.gov (United States)

Escoubet, C.-Philippe; Grison, Benjamin; Berchem, Jean; Trattner, Kralheinz; Pitout, Frederic; Richard, Robert; Taylor, Matt; Soucek, Jan; Laakso, Harri; Masson, Arnaud; Dunlop, Malcolm; Dandouras, Iannis; Reme, Henri; Fazakerley, Andrew; Daly, Patrick

2014-05-01

The exterior cusp is the most external region of the polar magnetosphere in direct contact with the plasma and the magnetic field from the solar wind. Unlike the rest of the magnetopause surface, the exterior cusp is a singular region with small and turbulent magnetic field and where large entry of plasma from solar origin takes place. The main process that injects solar wind plasma into the polar cusp is now generally accepted to be magnetic reconnection. Depending on the IMF direction, this process will take place equatorward (for IMF southward), poleward (for IMF northward) or on the dusk or dawn sides (for IMF azimuthal) of the cusp. We report a Cluster crossing on 5 January 2002 near the exterior cusp on the southern dusk side. The IMF was mainly azimuthal (IMF-By around -5 nT), the solar wind speed lower than usual around 280 km/s and the density around 5 cm-3. The four Cluster spacecraft were still in the "magnetotail" configuration with two perfect tetrahedra of 2000 km around apogee and turning into an elongated configuration near the magnetopause. C4 was the first spacecraft to enter the cusp around 19:52:04 UT, followed by C2 at 19:52:35 UT, C1 at 19:54:24 UT and C3 at 20:13:15 UT. C4 and C1 observed two ion energy dispersions at 20:10 UT and 20:40 UT and C3 at 20:35 UT and 21:15 UT. Using the time of flight technique on the upgoing and downgoing ions in the dispersions, we obtain an altitude of the sources of these ions between 14 and 20 RE. Using Tsyganenko model, these sources are located on the dusk flank, past the terminator. In addition, before entering the cusp, the magnetopause crossing was characterized by a large shear in By and bipolar plasma flows, suggesting that reconnection was taking place near the exterior cusp. We will discuss the extent of the reconnection line along the flank of the magnetopause based on these observations.

The cusp effect in η'→ηππ decays

International Nuclear Information System (INIS)

Kubis, Bastian; Schneider, Sebastian P.

2009-01-01

Strong final-state interactions create a pronounced cusp in η'→ηπ 0 π 0 decays. We adapt and generalize the non-relativistic effective field theory framework developed for the extraction of ππ scattering lengths from K→3π decays to this case. The cusp effect is predicted to have an effect of more than 8% on the decay spectrum below the π + π - threshold. (orig.)

Average spatial distributions of energetic particles in the midaltitude cusp/cleft region observed by Viking

International Nuclear Information System (INIS)

Kremser, G.; Lundin, R.

1990-01-01

The cusp/cleft region provides an entrance for magnetosheath particles into the magnetosphere and a sink for magnetospheric particles. In addition, strong acceleration and/or scattering of particles takes place. The Swedish satellite Viking crossed this region at midaltitudes. Measurements from this spacecraft were used to determine the average spatial distributions of H + and He ++ ions in the energy/charge range 2 keV/e ≤ E/Q ≤ 60 keV/e and of electrons with 7 keV ≤ E ≤ 97 keV. The data supply information on the structure of the midaltitude cusp/cleft region, the particle sources, and dynamical processes. Four different parts can be distinguished: (1) The cusp extends from about 76 degree to 82 degree invariant latitude (INL) and from 0800 to 1400 MLT. It is characterized by the presence of magnetosheath origin particles and important electron acceleration signatures. (2) A smaller region inside the cusp (77 degree-82 degree INL, 1000-1330 MLT) contains magnetosheath origin ions without electron acceleration. This is regarded as the cusp proper connected to the exterior cusp. (3) Poleward of the cusp magnetosheath origin ions are still present, but no magnetosheath electrons. This region is related to the plasma mantle. (4) Another region without magnetosheath origin ions but with strong electron acceleration extends equatorward of the cusp and probably constitutes part of the cleft, likely to be connected to the low-altitude boundary layer

Unruptured Aneurysm of Sinus of Valsalva Coexisting with the Large Ventricular Septal Defect and Severe Aortic Regurgitation in a Young Man

Directory of Open Access Journals (Sweden)

Pouya Nezafati

2015-01-01

Full Text Available Introduction. Unruptured sinus of valsalva aneurysm (SVA is a rare congenital anomaly, particularly, when it coexists with a ventricular septal defect (VSD and aortic regurgitation due to the prolapse of the elongated aortic cusp into the VSD. In this report, we present the case of a 19-year-old young man with VSD challenging in spite of dyspnea and lower limb edema. Presentation of Case. Its diagnosis was made on the basis of transthoracic echocardiography results. Surgical management consisted of replacing the SVA with mechanical valve prosthesis. A Gore-Tex patch repaired the VSD. Discussion. In the follow-up periods, clinical and echocardiographic tests showed that the patient was in excellent status. Conclusion. SVA requires a surgical procedure due to its high risk of mortality in unoperated patients and a good safety of surgery.

The dependence of cusp ion signatures on the reconnection rate

Directory of Open Access Journals (Sweden)

S. K. Morley

2003-04-01

Full Text Available The interpretation of structure in cusp ion dispersions is important for helping to understand the temporal and spatial structure of magnetopause reconnection. "Stepped" and "sawtooth" signatures have been shown to be caused by temporal variations in the reconnection rate under the same physical conditions for different satellite trajectories. The present paper shows that even for a single satellite path, a change in the amplitude of any reconnection pulses can alter the observed signature and even turn sawtooth into stepped forms and vice versa. On 20 August 1998, the Defense Meteorological Satellite Program (DMSP craft F-14 crossed the cusp just to the south of Longyearbyen, returning on the following orbit. The two passes by the DMSP F-14 satellites have very similar trajectories and the open-closed field line boundary (OCB crossings, as estimated from the SSJ/4 precipitating particle data and Polar UVI images, imply a similarly-shaped polar cap, yet the cusp ion dispersion signatures differ substantially. The cusp crossing at 08:54 UT displays a stepped ion dispersion previously considered to be typical of a meridional pass, whereas the crossing at 10:38 UT is a sawtooth form ion dispersion, previously considered typical of a satellite travelling longitudinally with respect to the OCB. It is shown that this change in dispersed ion signature is likely to be due to a change in the amplitude of the pulses in the reconnection rate, causing the stepped signature. Modelling of the low-energy ion cutoff under different conditions has reproduced the forms of signature observed.Key words. Ionosphere (particle precipitation Magnetospheric physics (energetic particles, precipitating, magnetopause, cusp and boundary layers

Design study of electrostatically plugged cusp fusion reactor

International Nuclear Information System (INIS)

Dolan, T.J.

1976-01-01

This study concentrates on the following aspects of an electrostatically plugged cusp reactor that will be different from other fusion reactor designs: the coil geometry and structural supports, high voltage electrodes, plasma parameters, power balance, and operating cycle. Assuming the electron density distribution in the anodes to have a characteristic width of two electron Larmor radii, which is consistent with present experimental results, the theory predicts that a device with a magnetic field strength, B = 8 T sustained solely by electron beam injection at 300 kV will have a power gain ratio, Q, of about 5. A toroidal multipole cusp configuration with six cusps was selected for the present design, based on a study of the ratio of plasma volume to coil volume. Coil forces are sustained by cryogenic trusses between like coils, fiberglass compression columns, and room temperature hoops. Radiation collimators in front of the high voltage electrodes greatly reduce the radiation impinging on the cathodes, helping to avoid breakdown and to prolong insulator life. The operating cycle consists of a startup period of about 20 s, followed by a fusion burn period lasting about 200 s (limited by impurity buildup) and a 20-s flushing period

Case studies of the storm time variation of the polar cusp

International Nuclear Information System (INIS)

Meng, C.

1983-01-01

The latitudinal variations of the polar cusp region were examined during three intense geomagnetic storms. The variations were compared with the intensity of storm time ring current inferred from the Dst index, with the magnitude of the north-south component B/sub z/ of the interplanetary magnetic field and with substorm activity. The common feature is that the rapid equatorward shift occurred during the increase of the ring current growth and during the southward turning of the interplanetary magnetic field orientation. The equatorwardmost latitude of the cusp was reached before the peak of the ring current intensity, by a few to several hours, coinciding with the occurrence of the largest magnitude of the southward interplanetary magnetic field component. However, details of the polar cusp latitudinal movement differ from storm to storm. During the three storms studied, the poleward recovery commenced at the peak magnitude of the negative IMF B/sub z/ component, but the recovery proceeded without a clear relation to variations of the interplanetary B/sub z/ component, to the ring current intensity, or to the substorm activity. The lowest cusp latitude observed was at approx.61.7 0 , and the magnitude of this shift seems to be related to the magnitudes of -B/sub z/. It is further observed that the approximate rates of the cusp macroscopic equatorward and poleward movements are about 3 0 and 1.5 0 per hour, respectively

A Collaborative Learning Network Approach to Improvement: The CUSP Learning Network.

Science.gov (United States)

Weaver, Sallie J; Lofthus, Jennifer; Sawyer, Melinda; Greer, Lee; Opett, Kristin; Reynolds, Catherine; Wyskiel, Rhonda; Peditto, Stephanie; Pronovost, Peter J

2015-04-01

Collaborative improvement networks draw on the science of collaborative organizational learning and communities of practice to facilitate peer-to-peer learning, coaching, and local adaption. Although significant improvements in patient safety and quality have been achieved through collaborative methods, insight regarding how collaborative networks are used by members is needed. Improvement Strategy: The Comprehensive Unit-based Safety Program (CUSP) Learning Network is a multi-institutional collaborative network that is designed to facilitate peer-to-peer learning and coaching specifically related to CUSP. Member organizations implement all or part of the CUSP methodology to improve organizational safety culture, patient safety, and care quality. Qualitative case studies developed by participating members examine the impact of network participation across three levels of analysis (unit, hospital, health system). In addition, results of a satisfaction survey designed to evaluate member experiences were collected to inform network development. Common themes across case studies suggest that members found value in collaborative learning and sharing strategies across organizational boundaries related to a specific improvement strategy. The CUSP Learning Network is an example of network-based collaborative learning in action. Although this learning network focuses on a particular improvement methodology-CUSP-there is clear potential for member-driven learning networks to grow around other methods or topic areas. Such collaborative learning networks may offer a way to develop an infrastructure for longer-term support of improvement efforts and to more quickly diffuse creative sustainment strategies.

Cusp-core problem and strong gravitational lensing

International Nuclear Information System (INIS)

Li Nan; Chen Daming

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 flat 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 of disk 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.

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

We examined some 75 observations from the low-altitude Earth orbiting DMSP, Orsted and CHAMP satellites which were taken in the region of the nominal cusp. Our objective was to determine whether the actually observed cusp locations as inferred from magnetosheath-like particle precipitation...... ("particle cusp") and intense small-scale magnetic field variations ("current cusp"), respectively, were identical and were consistent with the statistically expected latitude of the cusp derived from a huge number of charged particle spectrograms ("statistical cusp"). The geocentric coordinates...... of the 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...

Methods for quantitative measurement of tooth wear using the area and volume of virtual model cusps.

Science.gov (United States)

Kim, Soo-Hyun; Park, Young-Seok; Kim, Min-Kyoung; Kim, Sulhee; Lee, Seung-Pyo

2018-04-01

Clinicians must examine tooth wear to make a proper diagnosis. However, qualitative methods of measuring tooth wear have many disadvantages. Therefore, this study aimed to develop and evaluate quantitative parameters using the cusp area and volume of virtual dental models. The subjects of this study were the same virtual models that were used in our former study. The same age group classification and new tooth wear index (NTWI) scoring system were also reused. A virtual occlusal plane was generated with the highest cusp points and lowered vertically from 0.2 to 0.8 mm to create offset planes. The area and volume of each cusp was then measured and added together. In addition to the former analysis, the differential features of each cusp were analyzed. The scores of the new parameters differentiated the age and NTWI groups better than those analyzed in the former study. The Spearman ρ coefficients between the total area and the area of each cusp also showed higher scores at the levels of 0.6 mm (0.6A) and 0.8A. The mesiolingual cusp (MLC) showed a statistically significant difference ( P <0.01) from the other cusps in the paired t -test. Additionally, the MLC exhibited the highest percentage of change at 0.6A in some age and NTWI groups. Regarding the age groups, the MLC showed the highest score in groups 1 and 2. For the NTWI groups, the MLC was not significantly different in groups 3 and 4. These results support the proposal that the lingual cusp exhibits rapid wear because it serves as a functional cusp. Although this study has limitations due to its cross-sectional nature, it suggests better quantitative parameters and analytical tools for the characteristics of cusp wear.

Antihydrogen atom formation in a CUSP trap towards spin polarized beams

Energy Technology Data Exchange (ETDEWEB)

Kuroda, N., E-mail: kuroda@radphys4.c.u-tokyo.ac.jp [University of Tokyo, Graduate School of Arts and Sciences (Japan); Enomoto, Y. [RIKEN Advanced Science Institute (Japan); Michishio, K. [Tokyo University of Science, Department of Physics (Japan); Kim, C. H. [University of Tokyo, Graduate School of Arts and Sciences (Japan); Higaki, H. [Hiroshima University, Graduate School of Advanced Science of Matter (Japan); Nagata, Y.; Kanai, Y. [RIKEN Advanced Science Institute (Japan); Torii, H. A. [University of Tokyo, Graduate School of Arts and Sciences (Japan); Corradini, M.; Leali, M.; Lodi-Rizzini, E.; Venturelli, L.; Zurlo, N. [Universita di Brescia and Instituto Nazionale di Fisica Nucleare, Dipartimento di Chimica e Fisica per l' Ingegneria e per i Materiali (Italy); Fujii, K.; Ohtsuka, M.; Tanaka, K. [University of Tokyo, Graduate School of Arts and Sciences (Japan); Imao, H. [RIKEN Nishina Center for Accelerator-Based Science (Japan); Nagashima, Y. [Tokyo University of Science, Department of Physics (Japan); Matsuda, Y. [University of Tokyo, Graduate School of Arts and Sciences (Japan); Juhasz, B. [Stefan Meyer Institut fuer Subatomare Physik (Austria); and others

2012-12-15

The ASACUSA collaboration has been making a path to realize high precision microwave spectroscopy of ground-state hyperfine transitions of antihydrogen atom in flight for stringent test of the CPT symmetry. For this purpose, an efficient extraction of a spin polarized antihydrogen beam is essential. In 2010, we have succeeded in synthesizing our first cold antihydrogen atoms employing a CUSP trap. The CUSP trap confines antiprotons and positrons simultaneously with its axially symmetric magnetic field to form antihydrogen atoms. It is expected that antihydrogen atoms in the low-field-seeking states are preferentially focused along the cusp magnetic field axis whereas those in the high-field-seeking states are defocused, resulting in the formation of a spin-polarized antihydrogen beam.

On the cusp anomalous dimension in the ladder limit of N=4 SYM

Energy Technology Data Exchange (ETDEWEB)

Beccaria, Matteo; Fachechi, Alberto; Macorini, Guido [Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento,Via Arnesano, 73100 Lecce (Italy); INFN,Via Arnesano, 73100 Lecce (Italy)

2016-06-01

We analyze the cusp anomalous dimension in the (leading) ladder limit of N=4 SYM and present new results for its higher-order perturbative expansion. We study two different limits with respect to the cusp angle ϕ. The first is the light-like regime where x=e{sup i} {sup ϕ}→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 perturbation theory in a novel efficient way by means of a suitable all-order Ansatz for the ground state of the associated Schrödinger problem. Our perturbative setup allows to systematically derive higher-order perturbative corrections in powers of the cusp angle as explicit non-perturbative functions of the effective coupling. This series approximation is compared with the numerical solution of the Schrödinger equation to show that we can achieve very good accuracy over the whole range of coupling and cusp angle. Our results have been obtained by relatively simple techniques. Nevertheless, they provide several non-trivial tests useful to check the application of Quantum Spectral Curve methods to the ladder approximation at non zero ϕ, in the two limits we studied.

Valve-sparing aortic root repair in acute type A dissection: how many sinuses have to be repaired for curative surgery?

Science.gov (United States)

Urbanski, Paul P; Hijazi, Husam; Dinstak, Witold; Diegeler, Anno

2013-09-01

The aim of the study was to evaluate operative and long-term results of valve-sparing aortic root surgery in acute type A dissection. The repair consisted of selective replacement of all dissected and pathological sinuses. Forty-six patients (mean age 62 ± 14; range 29-88 years, 3 with Marfan syndrome), operated on between August 2001 and July 2011 due to acute type A aortic dissection, underwent valve-sparing root repair, resulting in a valve preservation rate of 56% in acute aortic dissection surgery involving the aortic root. Insufficiency grades of 0/1+, 2+, 3+ and 4+ were presented in 16, 17, 12 and 1 patients, respectively. Root repair with resection of the whole of the pathological aortic wall without the use of any glue was performed in all patients. Replacement of 1, 2 or 3 sinuses of Valsalva was performed in 29, 12 and 5 patients, respectively. Concomitant cusp repair was necessary in 7 patients. All perioperative data were collected prospectively and an intention-to-treat analysis was performed. A total of 6 patients (median age 76, range 63-81 years) died, on average 10 months (range 0.9-44) after surgery resulting in an overall survival of 87% at the mean follow-up of 54 ± 37, range 0.9-132 months. The linearized death rate was 2.9%/year, and the actuarial survival rate at 8 years was 85.5 ± 5.6%. No death was related to the aortic valve or aortic root. There were no valve-related events and no patient required reoperation on the proximal aorta/aortic valve during the follow-up. At the last echocardiography (47.8 ± 35.6 months after surgery), 33 patients showed no and 13 patients slight (1+) aortic insufficiency. Curative repair with replacement of all pathological sinuses of Valsalva leads to an excellent long-term outcome. Selected sinus repair is a simple and effective method of curative, valve-sparing root repair in acute aortic dissection because replacement of all sinuses is seldom necessary.

Connection of the positive phase of ionospheric storms with the day-time cusp

International Nuclear Information System (INIS)

Morozova, L.D.; Danilov, A.D.

1986-01-01

Data on the relation of ionospheric storms with the day-time cusp are considered. Experimental data on the velocity and direction of wind from the day-time cusp region, obtained for perturbed conditions on 30.12.1981, are analyzed. It is shown that perturbed wind from the cusp results in the increase of the value δf 0 F2 and under conditions before magnetic storm onset unambiguously causes positive ionosheric perturbation, and under conditions of a developed magnetic storm-either a positive perturbation or a decrease in the amplitude of negative perturbation

Acceleration of O+ from the cusp to the plasma sheet

Science.gov (United States)

Liao, J.; Kistler, L. M.; Mouikis, C. G.; Klecker, B.; Dandouras, I.

2015-02-01

Heavy ions from the ionosphere that are accelerated in the cusp/cleft have been identified as a direct source for the hot plasma in the plasma sheet. However, the details of the acceleration and transport that transforms the originally cold ions into the hot plasma sheet population are not fully understood. The polar orbit of the Cluster satellites covers the main transport path of the O+ from the cusp to the plasma sheet, so Cluster is ideal for tracking its velocity changes. However, because the cusp outflow is dispersed according to its velocity as it is transported to the tail, due to the velocity filter effect, the observed changes in beam velocity over the Cluster orbit may simply be the result of the spacecraft accessing different spatial regions and not necessarily evidence of acceleration. Using the Cluster Ion Spectrometry/Composition Distribution Function instrument onboard Cluster, we compare the distribution function of streaming O+ in the tail lobes with the initial distribution function observed over the cusp and reveal that the observations of energetic streaming O+ in the lobes around -20 RE are predominantly due to the velocity filter effect during nonstorm times. During storm times, the cusp distribution is further accelerated. In the plasma sheet boundary layer, however, the average O+ distribution function is above the upper range of the outflow distributions at the same velocity during both storm and nonstorm times, indicating that acceleration has taken place. Some of the velocity increase is in the direction perpendicular to the magnetic field, indicating that the E × B velocity is enhanced. However, there is also an increase in the parallel direction, which could be due to nonadiabatic acceleration at the boundary or wave heating.

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.

Acute Aortic Arch Perforation During Transcatheter Aortic Valve Replacement in Bicuspid Aortic Stenosis and a Gothic Aortic Arch.

Science.gov (United States)

Millan-Iturbe, Oscar; Sawaya, Fadi J; Bieliauskas, Gintautas; Chow, Danny H F; De Backer, Ole; Søndergaard, Lars

2017-09-01

Transcatheter aortic valve replacement (TAVR) has evolved from a novel technology to an established therapy for high/intermediate-risk patients with severe symptomatic aortic stenosis (AS). Although TAVR is used to treat bicuspid severe AS, the large randomized trials typically excluded bicuspid AS because of its unique anatomic features. This case report describes an acute aortic perforation during delivery of a transcatheter heart valve to treat a severe bicuspid AS with a "gothic aortic arch"; more careful evaluation of the preprocedural multislice computed tomographic scan would have unveiled a sharply angulated aortic arch. This life-threatening complication was successfully treated by thoracic endovascular aortic repair. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

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...

Fracture resistance of weakened teeth restored with condensable resin with and without cusp coverage

Directory of Open Access Journals (Sweden)

Rafael Francisco Lia Mondelli

2009-06-01

Full Text Available OBJECTIVES: This in vitro study evaluated the fracture resistance of weakened human premolars (MOD cavity preparation and pulp chamber roof removal restored with condensable resin composite with and without cusp coverage. MATERIAL AND METHODS: Thirty human maxillary premolars were divided into three groups: Group A (control, sound teeth; Group B, wide MOD cavities prepared and the pulp chamber roof removed and restored with resin composite without cusp coverage; Group C, same as Group B with 2.0 mm of buccal and palatal cusps reduced and restored with the same resin. The teeth were included in metal rings with self-curing acrylic resin, stored in water for 24 h and thereafter subjected to a compressive axial load in a universal testing machine at 0.5 mm/min. RESULTS: The mean fracture resistance values ± standart deviation (kgf were: group A: 151.40 ± 55.32, group B: 60.54 ± 12.61, group C: 141.90 ± 30.82. Statistically significant differences were found only between Group B and the other groups (p<0.05. The condensable resin restoration of weakened human premolars with cusp coverage significantly increased the fracture resistance of the teeth as compared to teeth restored without cusp coverage. CONCLUSION: The results showed that cusp coverage with condensable resin might be a safe option for restoring weakened endodontically treated teeth.

Stationary magnetospheric convection on November 24, 1981. 2. Small-scale structures in the dayside cusp/cleft

Directory of Open Access Journals (Sweden)

Y. I. Galperin

Full Text Available A case study of the dayside cusp/cleft region during an interval of stationary magnetospheric convection (SMC on November, 24, 1981 is presented, based on detailed measurements made by the AUREOL-3 satellite. Layered small-scale field-aligned current sheets, or loops, superimposed to a narrow V-shaped ion dispersion structure, were observed just equatorward from the region of the "cusp proper". The equatorward sheet was accompanied by a very intense and short (less than 1 s ion intensity spike at 100 eV. No major differences were noted of the characteristics of the LLBL, or "boundary cusp", and plasma mantle precipitation during this SMC period from those typical of the cusp/cleft region for similar IMF conditions. Simultaneous NOAA-6 and NOAA-7 measurements described in Despirak et al. were used to estimate the average extent of the "cusp proper" (defined by dispersed precipitating ions with the energy flux exceeding 10^-3 erg cm^-2 s^-1 during the SMC period, as ~0.73° ILAT width, 2.6-3.4 h in MLT, and thus the recently merged magnetic flux, 0.54-0.70 × 10⁷ Wb. This, together with the average drift velocity across the cusp at the convection throat, ~0.5 km s^-1, allowed to evaluate the cusp merging contribution to the total cross-polar cap potential difference, ~33.8-43.8 kV. It amounts to a quite significant part of the total cross-polar cap potential difference evaluated from other data. A "shutter" scenario is suggested for the ion beam injection/penetration through the stagnant plasma region in the outer cusp to explain the pulsating nature of the particle injections in the low- and medium-altitude cusp region.

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

A web-based tool for the Comprehensive Unit-based Safety Program (CUSP).

Science.gov (United States)

Pronovost, Peter J; King, Jay; Holzmueller, Christine G; Sawyer, Melinda; Bivens, Shauna; Michael, Michelle; Haig, Kathy; Paine, Lori; Moore, Dana; Miller, Marlene

2006-03-01

An organization's ability to change is driven by its culture, which in turn has a significant impact on safety. The six-step Comprehensive Unit-Based Safety Program (CUSP) is intended to improve local culture and safety. A Web-based project management tool for CUSP was developed and then pilot tested at two hospitals. HOW ECUSP WORKS: Once a patient safety concern is identified (step 3), a unit-level interdisciplinary safety committee determines issue criticality and starts up the projects (step 4), which are managed using project management tools within eCUSP (step 5). On a project's completion, the results are disseminated through a shared story (step 6). OSF St. Joseph's Medical Center-The Medical Birthing Center (Bloomington, Illinois), identified 11 safety issues, implemented 11 projects, and created 9 shared stories--including one for its Armband Project. The Johns Hopkins Hospital (Baltimore) Medical Progressive Care (MPC4) Unit identified 5 safety issues and implemented 4 ongoing projects, including the intravenous (IV) Tubing Compliance Project. The eCUSP tool's success depends on an organizational commitment to creating a culture of safety.

A comparison of fatigue resistance of three materials for cusp-replacing adhesive restorations.

NARCIS (Netherlands)

Kuijs, R.H.; Fennis, W.M.M.; Kreulen, C.M.; Roeters, F.J.M.; Verdonschot, N.J.J.; Creugers, N.H.J.

2006-01-01

OBJECTIVES: To investigate the fatigue resistance and failure behaviour of cusp-replacing restorations in premolars using different types of adhesive restorative materials. METHODS: A class 2 cavity was prepared and the buccal cusp was removed in an extracted sound human upper premolar. By using a

On the Casimir scaling violation in the cusp anomalous dimension at small angle

Science.gov (United States)

Grozin, Andrey; Henn, Johannes; Stahlhofen, Maximilian

2017-10-01

We compute the four-loop n f contribution proportional to the quartic Casimir of the QCD cusp anomalous dimension as an expansion for small cusp angle ϕ. This piece is gauge invariant, violates Casimir scaling, and first appears at four loops. It requires the evaluation of genuine non-planar four-loop Feynman integrals. We present results up to O({φ}^4) . One motivation for our calculation is to probe a recent conjecture on the all-order structure of the cusp anomalous dimension. As a byproduct we obtain the four-loop HQET wave function anomalous dimension for this color structure.

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)

Nakayama, Masafumi; Kyomasu, Yoshinori; Suzuki, Yasuko; Mashima, Yasuoki; Tanno, Munehiko; Endo, Kazuo; Yamada, Hideo

1990-01-01

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)

The Polar Cusp Observed by Cluster Under Constant Imf-Bz Southward

Science.gov (United States)

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

2011-12-01

The Earth's magnetic field is influenced by the interplanetary magnetic field (IMF), specially at the magnetopause where both magnetic fields enter in direct contact and magnetic reconnection can be initiated. In the polar regions, the polar cusp that extends from the magnetopause down to the ionosphere is also directly influenced. The reconnection not only allow ions and electrons from the solar wind to enter the polar cusp but also give an impulse to the magnetic field lines threading the polar cusp through the reconnection electric field. A dispersion in energy of the ions is subsequently produced by the motion of field lines and the time-of-flight effect on down-going ions. If reconnection is continuous and operates at constant rate, the ion dispersion is smooth and continuous. On the other hand if the reconnection rate varies, we expect interruption in the dispersion forming energy steps or staircase. Similarly, multiple entries near the magnetopause could also produce steps at low or mid-altitude when a spacecraft is crossing subsequently the field lines originating from these multiple sources. Cluster with four spacecraft following each other in the mid-altitude cusp can be used to distinguish between these "temporal" and "spatial" effects. We will show two Cluster cusp crossings where the spacecraft were separated by a few minutes. The energy dispersions observed in the first crossing were the same during the few minutes that separated the spacecraft. In the second crossing, two ion dispersions were observed on the first spacecraft and only one of the following spacecraft, about 10 min later. The detailed analysis indicates that these steps result from spatial structures.

Antihydrogen synthesis in a double-CUSP trap towards test of the CPT-symmetry

Energy Technology Data Exchange (ETDEWEB)

Radics, B., E-mail: balint.radics@cern.ch [ETH Zürich, Institute for Particle Physics (Switzerland); Ishikawa, S.; Kuroda, N. [University of Tokyo, Institute of Physics, Graduate School of Arts and Sciences (Japan); Murtagh, D. J.; Nagata, Y. [RIKEN, Atomic Physics Laboratory (Japan); Tajima, M. [University of Tokyo, Institute of Physics, Graduate School of Arts and Sciences (Japan); Gorp, S. Van [RIKEN, Atomic Physics Laboratory (Japan); Abo, Y. [Hiroshima University, Graduate School of Advanced Sciences of Matter (Japan); Dupre, P. [RIKEN, Atomic Physics Laboratory (Japan); Higashi, Y. [University of Tokyo, Institute of Physics, Graduate School of Arts and Sciences (Japan); Kaga, C. [Hiroshima University, Graduate School of Advanced Sciences of Matter (Japan); Leali, M.; Mascagna, V.; Venturelli, L.; Zurlo, N. [Universita di Brescia, Dipartimento di Ingegneria dell Informazione (Italy); Breuker, H. [CERN (Switzerland); Higaki, H. [Hiroshima University, Graduate School of Advanced Sciences of Matter (Japan); Kanai, Y. [RIKEN, Atomic Physics Laboratory (Japan); Rizzini, E. Lodi [Universita di Brescia, Dipartimento di Ingegneria dell Informazione (Italy); Matsuda, Y. [University of Tokyo, Institute of Physics, Graduate School of Arts and Sciences (Japan); and others

2016-12-15

The aim of the ASACUSA-CUSP experiment at CERN is to produce a cold, polarised antihydrogen beam and perform a high precision measurement of the ground-state hyperfine transition frequency of the antihydrogen atom and compare it with that of the hydrogen atom using the same spectroscopic beam line. Towards this goal a significant step was successfully accomplished: synthesised antihydrogen atoms have been produced in a CUSP magnetic configuration and detected at the end of our spectrometer beam line in 2012 [1]. During a long shut down at CERN the ASACUSA-CUSP experiment had been renewed by introducing a new double-CUSP magnetic configuration and a new semi-cylindrical tracking detector (AMT) [2], and by improving the transport feature of low energy antiproton beams. The new tracking detector monitors the antihydrogen synthesis during the mixing cycle of antiprotons and positrons. In this work the latest results and improvements of the antihydrogen synthesis will be presented including highlights from the last beam time.

Reliability and Identification of Aortic Valve Prolapse in the Horse

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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

The cusp effect in {eta}'{yields}{eta}{pi}{pi} decays

Energy Technology Data Exchange (ETDEWEB)

Kubis, Bastian; Schneider, Sebastian P. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Bonn (Germany)

2009-08-15

Strong final-state interactions create a pronounced cusp in {eta}'{yields}{eta}{pi}{sup 0}{pi}{sup 0} decays. We adapt and generalize the non-relativistic effective field theory framework developed for the extraction of {pi}{pi} scattering lengths from K{yields}3{pi} decays to this case. The cusp effect is predicted to have an effect of more than 8% on the decay spectrum below the {pi}{sup +}{pi}{sup -} threshold. (orig.)

EISCAT observations of plasma patches at sub-auroral cusp latitudes

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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.

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.

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

International Nuclear Information System (INIS)

Sandholt, P.E.; Egeland, A.

1987-10-01

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 B z 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

Quantification of abdominal aortic deformation after EVAR

Science.gov (United States)

Demirci, Stefanie; Manstad-Hulaas, Frode; Navab, Nassir

2009-02-01

Quantification of abdominal aortic deformation is an important requirement for the evaluation of endovascular stenting procedures and the further refinement of stent graft design. During endovascular aortic repair (EVAR) treatment, the aortic shape is subject to severe deformation that is imposed by medical instruments such as guide wires, catheters, and, the stent graft. This deformation can affect the flow characteristics and morphology of the aorta which have been shown to be elicitors for stent graft failures and be reason for reappearance of aneurysms. We present a method for quantifying the deformation of an aneurysmatic aorta imposed by an inserted stent graft device. The outline of the procedure includes initial rigid alignment of the two abdominal scans, segmentation of abdominal vessel trees, and automatic reduction of their centerline structures to one specified region of interest around the aorta. This is accomplished by preprocessing and remodeling of the pre- and postoperative aortic shapes before performing a non-rigid registration. We further narrow the resulting displacement fields to only include local non-rigid deformation and therefore, eliminate all remaining global rigid transformations. Finally, deformations for specified locations can be calculated from the resulting displacement fields. In order to evaluate our method, experiments for the extraction of aortic deformation fields are conducted on 15 patient datasets from endovascular aortic repair (EVAR) treatment. A visual assessment of the registration results and evaluation of the usage of deformation quantification were performed by two vascular surgeons and one interventional radiologist who are all experts in EVAR procedures.

On the energy shift the ECC cusp. Does the shift really exist?

International Nuclear Information System (INIS)

Sarkadi, L.; Barrachina, R.O.

2004-01-01

The cusplike 'electron capture to the continuum' (ECC) peak appearing in the spectrum of the forward emitted electrons in ion-atom collisions are generally thought to be a divergence. Recently Shah et al., however, claimed that 'the ECC cusp is indeed a cusp, and not a divergence smoothed by the experiment'. These authors measured the ECC cusp for collisions of 10- and 20-keV protons with H 2 and He, and found that the peak was shifted to lower velocity than its expected position. We also carried out CTMC calculations (for the case of 20-keV protons on He) by which we demonstrated that the shift really exists but its value depends on the angular window of the electron detection. (K.A.)

Mid-term outcomes of endovascular aortic aneurysm repair with carbon dioxide-guided angiography.

Science.gov (United States)

Takeuchi, Yuriko; Morikage, Noriyasu; Matsuno, Yutaro; Nakamura, Tamami; Samura, Makoto; Ueda, Koshiro; Harada, Takasuke; Ikeda, Yoshitaka; Suehiro, Kotaro; Ito, Hiroshi; Sakata, Kensuke; Hamano, Kimikazu

2018-05-14

Although iodinated contrast (IC) agents are commonly used in endovascular aneurysm repair (EVAR), perioperative use in patients with renal dysfunction or IC allergies is avoided. Carbon dioxide (CO 2 )-guided angiography is a promising alternative. We aimed to evaluate short-term and mid-term outcomes of EVAR using CO 2 -guided angiography. Three hundred and eighty-one patients who underwent EVAR from January 2012 to September 2016 were retrospectively reviewed and divided into an IC-EVAR group (n=351) and CO 2 -EVAR group (n=30). Subjects in the CO 2 -EVAR group had severe renal dysfunction (n=27) and IC allergy (n=4). Intraoperative, postoperative, and follow-up variables were compared. Compared to the IC-EVAR group, preoperative serum creatinine level was significantly higher (2.0 vs. 0.92 mg/dL, P < .0001) and mean IC dose significantly lower (18 vs. 55 mL P < .0001) in the CO 2 -EVAR group. The fluoroscopy time, operative time, number of stent grafts placed, and technical success rates of the groups were similar; no type I and/or type III endoleaks were detected on completion angiography. There was no acute kidney injury and one case of intestinal necrosis in the CO 2 -EVAR group, potentially due to cholesterol embolism. Postoperative endoleak, enlargement of aneurysms, survival, freedom from secondary intervention, and renal function change up to 3 months postoperatively were similar between groups. CO 2 -EVAR is technically feasible and exhibits prominent renal protection. However, consideration of the aortic lumen status remains an important challenge. Copyright © 2018. Published by Elsevier Inc.

Determination of polar cusp position by low-energy particle measurements made aboard AUREOLE satellite

International Nuclear Information System (INIS)

Gladyshev, V.A.; Jorjio, M.V.; Shuiskaya, F.K.; Crasnier, J.; Sauvaud, J.A.

1974-01-01

The Franco-Soviet experiment ARCAD, launched aboard the satellite AUREOLE December 27, 1971, has verified the existence of a particle penetration from the transition zone up to ionospheric altitudes across the polar cusp. The polar cusp is characterized by proton fluxes >10 7 particles/(cm 2 .s.sr.KeV) at 0.5KeV, with energy spectra similar to those in the transition zone. The position and form of the polar cusp are studied from measurements of protons in the range 0.4 to 30KeV during geomagnetically quiet periods (Kp [fr

Tunable system for production of mirror and cusp configurations using chassis of permanent magnets

Science.gov (United States)

Hyde, Alexander; Bushmelov, Maxim; Batishchev, Oleg

2018-03-01

Compact arrays of permanent magnets have shown promise as replacements for electromagnets in applications requiring magnetic cusps and mirrors. An adjustable system capable of suspending and translating a pair of light, nonmagnetic chassis carrying such sources of magnetic field has been designed and constructed. Using this device to align two cylindrical chassis, strong solenoid-like domains of field, as well as classic biconic cusp and magnetic mirror topologies, are generated. Employing a pair of ring-shaped chassis instead, the superposition of their naturally-emitted cusps is demonstrated to produce sextupolar and octupolar magnetic fields.

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.)

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)

Bangard, Christopher; Franke, Mareike; Maintz, David; Chang, De-Hua; Pfister, Roman; Deppe, Antje-Christin; Matoussevitch, Vladimir

2014-01-01

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.)

Aortic insufficiency

Science.gov (United States)

... page, please enable JavaScript. Aortic insufficiency is a heart valve disease in which the aortic valve does not close ... aortic insufficiency Images Aortic insufficiency References Carabello BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

Observations of an enhanced convection channel in the cusp ionosphere

International Nuclear Information System (INIS)

Pinnock, M.; Rodger, A.S.; Dudeney, J.R.; Baker, K.B.; Neweli, P.T.; Greenwald, R.A.; Greenspan, M.E.

1993-01-01

Transient or patchy magnetic field line merging on the dayside magnetopause, giving rise to flux transfer events (FTEs), is thought to play a significant role in energizing high-latitude ionospheric convection during periods of southward interplanetary magnetic field. Several transient velocity patterns in the cusp ionosphere have been presented as candidate FTE signatures. Instrument limitations, combined with uncertainties about ionospheric signature of FTEs have yet to be presented. This paper describes combined observations by the PACE HF backscatter radar and the DMSP F9 polar-orbiting satellite of a transient velocity signature in the southern hemispheric cusp. The prevailing solar wind conditions suggest that it is the result of enhanced magnetic merging at the magnetopause. The satellite particle precipitation data associated with the transient are typically cusplike in nature. The presence of spatially discrete patches of accelerated ions at the equatorward edge of the cusp is consistent with the ion acceleration that could occur with merging. The combined radar line-of-sight velocity data and the satellite transverse plasma drift data are consistent with a channel of enhanced convection superposed on the ambient cusp plasma flow. This channel is at least 900 km in longitudinal extent but only 100 km wide. It is zonally aligned for most of its extent, except at the western limit where it rotates sharply poleward. Weak return flow is observed outside the channel. These observations are compared with and contrasted to similar events seen by the EISCAT radar and by optical instruments. 30 refs., 2 figs

Early results of valve-sparing ascending aortic replacement in type A aortic dissection and aortic insufficiency

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М. Л. Гордеев

2016-08-01

Full Text Available Aim: The study was designed to investigate predictors of effective valve-sparing ascending aortic replacement in patients with Stanford type A aortic dissection combined with aortic insufficiency and to analyze efficacy and safety of this kind of surgery.Methods: From January 2010 to December 2015, 49 patients with Stanford type A aortic dissection combined with aortic insufficiency underwent ascending aortic replacement. All patients were divided into 3 groups: valve-sparing procedures (group 1, n = 11, combined aortic valve and supracoronary ascending aortic replacement (group 2, n = 12, and Bentall procedure (group 3, n = 26. We assessed the initial status of patients, incidence of complications and efficacy of valve-sparing ascending aortic replacement.Results: The hospital mortality rate was 8.2% (4/49 patients. The amount of surgical correction correlated with the initial diameter of the aorta at the level of the sinuses of Valsalva. During the hospital period, none of patients from group 1 developed aortic insufficiency exceeding Grade 2 and the vast majority of patients had trivial aortic regurgitation. The parameters of cardiopulmonary bypass, cross-clamp time and circulatory arrest time did not correlate with the initial size of the ascending aorta and aortic valve blood flow impairment, neither did they influence significantly the incidence and severity of neurological complications. The baseline size of the ascending aorta and degree of aortic regurgitation did not impact the course of the early hospital period.Conclusions: Supracoronary ascending aortic replacement combined with aortic valve repair in ascending aortic dissection and aortic regurgitation is effective and safe. The initial size of the ascending aorta and aortic arch do not influence immediate results. The diameter of the aorta at the level of the sinuses of Valsalva and the condition of aortic valve leaflets could be considered as the limiting factors. Further long

UV Observations of Atomic Oxygen in the Cusp Region

Science.gov (United States)

Fritz, B.; Lessard, M.; Dymond, K.; Kenward, D. R.; Lynch, K. A.; Clemmons, J. H.; Hecht, J. H.; Hysell, D. L.; Crowley, G.

2017-12-01

The Rocket Experiment for Neutral Upwelling (RENU) 2 launched into the dayside cusp on 13 December, 2015. The sounding rocket payload carried a comprehensive suite of particle, field, and remote sensing instruments to characterize the thermosphere in a region where pockets of enhanced neutral density have been detected [Lühr et al, 2004]. An ultraviolet photomultiplier tube (UV PMT) was oriented to look along the magnetic field line and remotely detect neutral atomic oxygen (OI) above the payload. The UV PMT measured a clear enhancement as the payload descended through a poleward moving auroral form, an indicator of structure in both altitude and latitude. Context for the UV PMT measurement is provided by the Special Sensor Ultraviolet Imager (SSULI) instrument on the Defense Meteorological Space Program (DMSP) satellite, which also measured OI as it passed through the cusp. UV tomography of SSULI observations produces a two-dimensional cross-section of volumetric emission rates in the high-latitude thermosphere prior to the RENU 2 flight. The volume emission rate may then be inverted to produce a profile of neutral density in the thermosphere. A similar technique is used to interpret the UV PMT measurement and determine structure in the thermosphere as RENU 2 descended through the cusp.

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

Science.gov (United States)

Shapiro, Stuart L; Shelton, Jessie

2016-06-15

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.

Classical description of the electron capture to the continuum cusp formation in ion-atom collisions

International Nuclear Information System (INIS)

Illescas, Clara; Pons, B.; Riera, A.

2002-01-01

Classical calculations are used to describe the dynamics of the electron capture to the continuum (ECC) cusp formation in H + +He collisions. We illustrate the frontier character of the ECC electrons between capture and ionization, and confirm that it is a temporary capture, through projectile focusing, that is responsible for the ECC cusp. Furthermore, the cusp is not a divergence smoothed by the experiment, and is slightly shifted from the impact-velocity value because of the residual pull from the target after ionization. This shift is larger the smaller the nuclear velocity

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

International Nuclear Information System (INIS)

Souza Dutra, A. de; Parise, J.A.R.; Souza Mendes, P.R. de.

1986-01-01

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) [pt

Qureshi-5 Catheter for Complex Supra- and Abdominal-Aortic Catheterization.

Science.gov (United States)

Qureshi, Adnan I; Xiao, WeiGang; Liu, HongLiang

2015-10-01

The use of previously described catheter technique was expanded to complex supra- and abdominal- aortic catheterizations. A new (Qureshi 5) catheter with curved shape at the distal end that has two lumens was used. One of lumens can accommodate a 0.035-inch guide wire and the second lumen can accommodate a 0.018-inch guide wire and terminates at the beginning of the distal curve of the first lumen. The manipulation and engagement of the curved distal end catheter was facilitated by rotation and movement of the J-shaped 0.018-inch guide wire extended coaxial and beyond the distal end of catheter. Subsequently, either contrast was injected or a 0.035-inch guide wire advanced into the target artery. The catheters were used in one patient to perform diagnostic cerebral and abdominal angiography through a 6F introducer sheath placed in the right common femoral artery. The catheterization was complex because of severe tortuosity of arch and descending aorta secondary to kyphosis. The left and right internal carotid arteries and left and right vertebral arteries, left renal artery, and superior mesenteric artery were catheterized in patient (fluoroscopy time 19:46 min). No complications were observed in the patient. The Qureshi-5 catheter was successful in complex supra- and abdominal-aortic catheterizations.

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.

Particle loss from magnetic cusp field

International Nuclear Information System (INIS)

Namba, C.; Kawamura, T.; Obayashi, H.

1974-12-01

The motion of charged particles in an axially symmetric magnetic field of cusp configuration is studied by means of numerical calculations. A particular attention is paid to a non-adiabatic zone. The computer results are compared with a simplified loss cone model and it is shown that there is a critical value of non-adiabaticity parameter which defines an effective size of the non-adiabatic zone. (auth.)

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

International Nuclear Information System (INIS)

Soeraas, F.

1977-12-01

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.)

Preliminary results in double cusp tandem mirror MM-4U

International Nuclear Information System (INIS)

Ming Linzhou; Tian Zhongyu; Feng Xiaozhen

1990-10-01

MM-4U device and preliminary experimental results are presented. Main results are as follows: The plasma has been produced by means of the injection of strong electron current; the axial profile of the plasma potential and the plasma electron density have been obtained respectively, they had a simular form; the plasma potential in the centre of the east cusp, the west cusp and the simple mirror; V e = -180V, V w = -164V, V m -1.8V; the electron density: n e = 1.7 x 10 11 cm -3 , n w = 4.7 x 10 10 cm -3 , n m = 7.5 x 10 7 cm -3 ; the electron temperature: T e = (19.9 ± 1.6) eV, T w = (20.7 ± 1.7) eV; the plasma pressure at 8 cm on the right of the west cusp centre is about 6.76 Pa, β ≅ 1.7 x 10 -3 . The plasma instability has been observed in the simple mirror, its vibration frequency was 7∼9.2 kHz. The results are discussed. The next new task of the physical experiment are proposed

Cusp electron production in 75--300 keV He+ + Ar collisions

International Nuclear Information System (INIS)

Plano, V.L.; Sarkadi, L.; Zavodszky, P.; Berenyi, D.; Palinkas, J.; Gulyas, L.; Takacs, E.; Toth, L.; Tanis, J.A.

1992-01-01

Cusp-electron production has been investigated in collisions of 75--300 keV He + with Ar. The relative contributions from electron capture to the continuum (ECC), transfer ionization (TI), and electron loss to the continuum (ELC) to the total cusp electron production were measured. Over the energy range investigated, ECC was found to decrease from about 86% to 80%, TI decreased from about 12% to 1%, and ELC increased from about 2% to 20%. The present results are consistent with earlier work for He + and O q+ projectiles

MMP-2 Isoforms in Aortic Tissue and Serum of Patients with Ascending Aortic Aneurysms and Aortic Root Aneurysms

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Tscheuschler, Anke; Meffert, Philipp; Beyersdorf, Friedhelm; Heilmann, Claudia; Kocher, Nadja; Uffelmann, Xenia; Discher, Philipp; Siepe, Matthias; Kari, Fabian A.

2016-01-01

Objective The need for biological markers of aortic wall stress and risk of rupture or dissection of ascending aortic aneurysms is obvious. To date, wall stress cannot be related to a certain biological marker. We analyzed aortic tissue and serum for the presence of different MMP-2 isoforms to find a connection between serum and tissue MMP-2 and to evaluate the potential of different MMP-2 isoforms as markers of high wall stress. Methods Serum and aortic tissue from n = 24 patients and serum from n = 19 healthy controls was analyzed by ELISA and gelatin zymography. 24 patients had ascending aortic aneurysms, 10 of them also had aortic root aneurysms. Three patients had normally functioning valves, 12 had regurgitation alone, eight had regurgitation and stenosis and one had only stenosis. Patients had bicuspid and tricuspid aortic valves (9/15). Serum samples were taken preoperatively, and the aortic wall specimen collected during surgical aortic repair. Results Pro-MMP-2 was identified in all serum and tissue samples. Pro-MMP-2 was detected in all tissue and serum samples from patients with ascending aortic/aortic root aneurysms, irrespective of valve morphology or other clinical parameters and in serum from healthy controls. We also identified active MMP-2 in all tissue samples from patients with ascending aortic/aortic root aneurysms. None of the analyzed serum samples revealed signals relatable to active MMP-2. No correlation between aortic tissue total MMP-2 or tissue pro-MMP-2 or tissue active MMP-2 and serum MMP-2 was found and tissue MMP-2/pro-MMP-2/active MMP-2 did not correlate with aortic diameter. This evidence shows that pro-MMP-2 is the predominant MMP-2 species in serum of patients and healthy individuals and in aneurysmatic aortic tissue, irrespective of aortic valve configuration. Active MMP-2 species are either not released into systemic circulation or not detectable in serum. There is no reliable connection between aortic tissue—and serum MMP-2

[Reliability study in the measurement of the cusp inclination angle of a chairside digital model].

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Xinggang, Liu; Xiaoxian, Chen

2018-02-01

This study aims to evaluate the reliability of the software Picpick in the measurement of the cusp inclination angle of a digital model. Twenty-one trimmed models were used as experimental objects. The chairside digital impression was then used for the acquisition of 3D digital models, and the software Picpick was employed for the measurement of the cusp inclination of these models. The measurements were repeated three times, and the results were compared with a gold standard, which was a manually measured experimental model cusp angle. The intraclass correlation coefficient (ICC) was calculated. The paired t test value of the two measurement methods was 0.91. The ICCs between the two measurement methods and three repeated measurements were greater than 0.9. The digital model achieved a smaller coefficient of variation (9.9%). The software Picpick is reliable in measuring the cusp inclination of a digital model.

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

International Nuclear Information System (INIS)

Berg, H. Rogier van den; Leijdekkers, Vanessa J.; Vahl, Anco

2006-01-01

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

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

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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 R_E 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

Influence of different cusp coverage methods for the extension of ceramic inlays on marginal integrity and enamel crack formation in vitro.

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Krifka, Stephanie; Stangl, Martin; Wiesbauer, Sarah; Hiller, Karl-Anton; Schmalz, Gottfried; Federlin, Marianne

2009-09-01

No information is available to date about cusp design of thin (1.0 mm) non-functional cusps and its influence upon (1) marginal integrity of ceramic inlays (CI) and partial ceramic crowns (PCC) and (2) crack formation of dental tissues. The aim of this in vitro study was to investigate the effect of cusp coverage of thin non-functional cusps on marginal integrity and enamel crack formation. CI and PCC preparations were performed on extracted human molars. Non-functional cusps were adjusted to 1.0-mm wall thickness and 1.0-mm wall thickness with horizontal reduction of about 2.0 mm. Ceramic restorations (Vita Mark II, Cerec3 System) were adhesively luted with Excite/Variolink II. The specimens were exposed to thermocycling and central mechanical loading. Marginal integrity was assessed by evaluating dye penetration after thermal cycling and mechanical loading. Enamel cracks were documented under a reflective-light microscope. The data were statistically analysed with the Mann-Whitney U test, the Fishers exact test (alpha = 0.05) and the error rates method. PCC with horizontal reduction of non-functional cusps showed statistically significant less microleakage than PCC without such a cusp coverage. Preparation designs with horizontal reduction of non-functional cusps showed a tendency to less enamel crack formation than preparation designs without cusp coverage. Thin non-functional cusp walls of adhesively bonded restorations should be completely covered or reduced to avoid enamel cracks and marginal deficiency.

Cusps enable line attractors for neural computation

International Nuclear Information System (INIS)

Xiao, Zhuocheng; Zhang, Jiwei; Sornborger, Andrew T.; Tao, Louis

2017-01-01

Here, line attractors in neuronal networks have been suggested to be the basis of many brain functions, such as working memory, oculomotor control, head movement, locomotion, and sensory processing. In this paper, we make the connection between line attractors and pulse gating in feed-forward neuronal networks. In this context, because of their neutral stability along a one-dimensional manifold, line attractors are associated with a time-translational invariance that allows graded information to be propagated from one neuronal population to the next. To understand how pulse-gating manifests itself in a high-dimensional, nonlinear, feedforward integrate-and-fire network, we use a Fokker-Planck approach to analyze system dynamics. We make a connection between pulse-gated propagation in the Fokker-Planck and population-averaged mean-field (firing rate) models, and then identify an approximate line attractor in state space as the essential structure underlying graded information propagation. An analysis of the line attractor shows that it consists of three fixed points: a central saddle with an unstable manifold along the line and stable manifolds orthogonal to the line, which is surrounded on either side by stable fixed points. Along the manifold defined by the fixed points, slow dynamics give rise to a ghost. We show that this line attractor arises at a cusp catastrophe, where a fold bifurcation develops as a function of synaptic noise; and that the ghost dynamics near the fold of the cusp underly the robustness of the line attractor. Understanding the dynamical aspects of this cusp catastrophe allows us to show how line attractors can persist in biologically realistic neuronal networks and how the interplay of pulse gating, synaptic coupling, and neuronal stochasticity can be used to enable attracting one-dimensional manifolds and, thus, dynamically control the processing of graded information.

Cusps enable line attractors for neural computation

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Xiao, Zhuocheng; Zhang, Jiwei; Sornborger, Andrew T.; Tao, Louis

2017-11-01

Line attractors in neuronal networks have been suggested to be the basis of many brain functions, such as working memory, oculomotor control, head movement, locomotion, and sensory processing. In this paper, we make the connection between line attractors and pulse gating in feed-forward neuronal networks. In this context, because of their neutral stability along a one-dimensional manifold, line attractors are associated with a time-translational invariance that allows graded information to be propagated from one neuronal population to the next. To understand how pulse-gating manifests itself in a high-dimensional, nonlinear, feedforward integrate-and-fire network, we use a Fokker-Planck approach to analyze system dynamics. We make a connection between pulse-gated propagation in the Fokker-Planck and population-averaged mean-field (firing rate) models, and then identify an approximate line attractor in state space as the essential structure underlying graded information propagation. An analysis of the line attractor shows that it consists of three fixed points: a central saddle with an unstable manifold along the line and stable manifolds orthogonal to the line, which is surrounded on either side by stable fixed points. Along the manifold defined by the fixed points, slow dynamics give rise to a ghost. We show that this line attractor arises at a cusp catastrophe, where a fold bifurcation develops as a function of synaptic noise; and that the ghost dynamics near the fold of the cusp underly the robustness of the line attractor. Understanding the dynamical aspects of this cusp catastrophe allows us to show how line attractors can persist in biologically realistic neuronal networks and how the interplay of pulse gating, synaptic coupling, and neuronal stochasticity can be used to enable attracting one-dimensional manifolds and, thus, dynamically control the processing of graded information.

Results of aortic root reimplantation in patients with ascending aortic aneurysm and concomitant aortic insufficiency

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А. М. Чернявский

2016-01-01

Full Text Available Objective. The research was designed to evaluate the results of valve-sparing operations: aortic root reimplantation versus aortic valve reimplantation when repairing an ascending aortic aneurysm with concomitant aortic insufficiency.Methods. Within a blind prospective randomized study conducted over a period from 2011 to 2015, 64 patients underwent aortic valve-sparing surgery. The inclusion criteria were the presence of an aortic aneurysm of the ascending aorta exceeding 4.5 cm and concomitant aortic insufficiency. All patients were divided into two groups: FS-group, aortic root reimplantation (modified Florida Sleeve technique (n = 32 and D-group, aortic valve reimplantation (David procedure (n = 32. The average age of patients was 57±13 (23–73 years in the FS-group and 55±11 (15–72 years in the D-group (p = 0.54. Both groups had 78% of males (p>0.99. A Marfan syndrome was identified in 6% and 9% in the FS-group and D-group respectively (p>0.99. Mean diameter of the sinuses of Valsalva was 51±7 mm and 56±10 mm (p = 0.09, aortic insufficiency 2.6±0.7 and 2.8±0.8 (p = 0.15 in the FS-group and D-group respectively. In the FS-group and D-group LVEDD amounted to 5.5±0.7 mm and 5.9±1.0 mm (p = 0.09 respectively. All patients took echocardiography in the preoperative, postoperative and follow-up periods.Results. In the long-term period, the degree of aortic regurgitation was 1.2±0.1 in the FS-group and 1.3±0.6 in the D-group (p = 0.72. LVEDD was 123±23 mm in the FS-group and 139.6±80 mm in the D-group at follow-up (p = 0.77. There were no statistically significant differences in the analysis of complications. Overall 30-day in-hospital mortality was 7.8%. There were 2 (6.3% deaths in the FS-group and 3 (9.4% in the D-group (p = 0.5.Late mortality was 6.3% in the FS-group and 3.1% in the D-group (p>0.99. Cumulative survival at 4 years was 84.3% and 84.8% in the FS-group and the D-group respectively (p = 0.94. Cumulative freedom from

First magnetic resonance imaging-guided aortic stenting and cava filter placement using a polyetheretherketone-based magnetic resonance imaging-compatible guidewire in swine: proof of concept.

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Kos, Sebastian; Huegli, Rolf; Hofmann, Eugen; Quick, Harald H; Kuehl, Hilmar; Aker, Stephanie; Kaiser, Gernot M; Borm, Paul J A; Jacob, Augustinus L; Bilecen, Deniz

2009-05-01

The purpose of this study was to demonstrate feasibility of percutaneous transluminal aortic stenting and cava filter placement under magnetic resonance imaging (MRI) guidance exclusively using a polyetheretherketone (PEEK)-based MRI-compatible guidewire. Percutaneous transluminal aortic stenting and cava filter placement were performed in 3 domestic swine. Procedures were performed under MRI-guidance in an open-bore 1.5-T scanner. The applied 0.035-inch guidewire has a PEEK core reinforced by fibres, floppy tip, hydrophilic coating, and paramagnetic markings for passive visualization. Through an 11F sheath, the guidewire was advanced into the abdominal (swine 1) or thoracic aorta (swine 2), and the stents were deployed. The guidewire was advanced into the inferior vena cava (swine 3), and the cava filter was deployed. Postmortem autopsy was performed. Procedural success, guidewire visibility, pushability, and stent support were qualitatively assessed by consensus. Procedure times were documented. Guidewire guidance into the abdominal and thoracic aortas and the inferior vena cava was successful. Stent deployments were successful in the abdominal (swine 1) and thoracic (swine 2) segments of the descending aorta. Cava filter positioning and deployment was successful. Autopsy documented good stent and filter positioning. Guidewire visibility through applied markers was rated acceptable for aortic stenting and good for venous filter placement. Steerability, pushability, and device support were good. The PEEK-based guidewire allows either percutaneous MRI-guided aortic stenting in the thoracic and abdominal segments of the descending aorta and filter placement in the inferior vena cava with acceptable to good device visibility and offers good steerability, pushability, and device support.

First Magnetic Resonance Imaging-Guided Aortic Stenting and Cava Filter Placement Using a Polyetheretherketone-Based Magnetic Resonance Imaging-Compatible Guidewire in Swine: Proof of Concept

International Nuclear Information System (INIS)

Kos, Sebastian; Huegli, Rolf; Hofmann, Eugen; Quick, Harald H.; Kuehl, Hilmar; Aker, Stephanie; Kaiser, Gernot M.; Borm, Paul J. A.; Jacob, Augustinus L.; Bilecen, Deniz

2009-01-01

The purpose of this study was to demonstrate feasibility of percutaneous transluminal aortic stenting and cava filter placement under magnetic resonance imaging (MRI) guidance exclusively using a polyetheretherketone (PEEK)-based MRI-compatible guidewire. Percutaneous transluminal aortic stenting and cava filter placement were performed in 3 domestic swine. Procedures were performed under MRI-guidance in an open-bore 1.5-T scanner. The applied 0.035-inch guidewire has a PEEK core reinforced by fibres, floppy tip, hydrophilic coating, and paramagnetic markings for passive visualization. Through an 11F sheath, the guidewire was advanced into the abdominal (swine 1) or thoracic aorta (swine 2), and the stents were deployed. The guidewire was advanced into the inferior vena cava (swine 3), and the cava filter was deployed. Postmortem autopsy was performed. Procedural success, guidewire visibility, pushability, and stent support were qualitatively assessed by consensus. Procedure times were documented. Guidewire guidance into the abdominal and thoracic aortas and the inferior vena cava was successful. Stent deployments were successful in the abdominal (swine 1) and thoracic (swine 2) segments of the descending aorta. Cava filter positioning and deployment was successful. Autopsy documented good stent and filter positioning. Guidewire visibility through applied markers was rated acceptable for aortic stenting and good for venous filter placement. Steerability, pushability, and device support were good. The PEEK-based guidewire allows either percutaneous MRI-guided aortic stenting in the thoracic and abdominal segments of the descending aorta and filter placement in the inferior vena cava with acceptable to good device visibility and offers good steerability, pushability, and device support.

Involvement of proinflammatory S100A9/A8 in the atherocalcinosis of aortic valves

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R. А. Moskalenko

2017-04-01

Full Text Available According to the results of the Euro-Heart Survey on Vascular Heart Disease the most common pathology is nonrheumatic aortic stenosis, it is also called as calcific aortic valve stenosis (CAVS, as in its pathogenesis the process of biomineralization of valve cusps and ring plays the main role. The aim of the work is the immunohistochemical study of mineralized tissue of aortic heart valves, which are affected by atherocalcinosis. Materials and methods. 30 samples of mineralized aortic valves (I group and 10 samples of aortic valve without evidence of biomineralization (II group -– control were studied. Immunohistochemical study of expression of collagen (Collagen I, CD68, myeloperoxidase (MPO, calgranulin A (S100A8, calgranulin B (S100A9, caspase 3 (Casp 3 and osteopontin (OPN was conducted in AV tissue of both groups. Results. In CAV tissues the fibrillar component (collagen I growths was found, but the quantitative and qualitative compositions of CD68+ circulating inflammatory cells are not significantly different from the control group. CAVs contain much more MPO+ -cells (p <0.001 in comparison to the group of AVs without biomineralization. Our data show a significant increase of the S100A9 and OPN expression in the mineralized tissue of AVs (p < 0.01. Also, a higher expression level of Casp3 and MPO was found in CAVs (p < 0.05. Comparing the first and the second groups of AVs connection between the expression of S100A8 was not determined. Conclusion. High Casp 3 expression confirms the increased level of cell elimination in the CAVs tissue, which is obviously connected with the impact of high local concentrations of S100A9. These facts can contribute to the development of pathological biomineralization of AV. Since osteopontin inhibits the hydroxyapatite formation by binding to the surface of the crystals, its hyperproduction is a counteracting factor against biomineralization in AV tissue.

Doppler-guided retrograde catheterization system

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Frazin, Leon J.; Vonesh, Michael J.; Chandran, Krishnan B.; Khasho, Fouad; Lanza, George M.; Talano, James V.; McPherson, David D.

1991-05-01

The purpose of this study was to investigate a Doppler guided catheterization system as an adjunctive or alternative methodology to overcome the disadvantages of left heart catheterization and angiography. These disadvantages include the biological effects of radiation and the toxic and volume effects of iodine contrast. Doppler retrograde guidance uses a 20 MHz circular pulsed Doppler crystal incorporated into the tip of a triple lumen multipurpose catheter and is advanced retrogradely using the directional flow information provided by the Doppler waveform. The velocity detection limits are either 1 m/second or 4 m/second depending upon the instrumentation. In a physiologic flow model of the human aortic arch, multiple data points revealed a positive wave form when flow was traveling toward the catheter tip indicating proper alignment for retrograde advancement. There was a negative wave form when flow was traveling away from the catheter tip if the catheter was in a branch or bent upon itself indicating improper catheter tip position for retrograde advancement. In a series of six dogs, the catheter was able to be accurately advanced from the femoral artery to the left ventricular chamber under Doppler signal guidance without the use of x-ray. The potential applications of a Doppler guided retrograde catheterization system include decreasing time requirements and allowing safer catheter guidance in patients with atherosclerotic vascular disease and suspected aortic dissection. The Doppler system may allow left ventricular pressure monitoring in the intensive care unit without the need for x-ray and it may allow left sided contrast echocardiography. With pulse velocity detection limits of 4 m/second, this system may allow catheter direction and passage into the aortic root and left ventricle in patients with aortic stenosis. A modification of the Doppler catheter may include transponder technology which would allow precise catheter tip localization once the

Decreased expression of fibulin-4 in aortic wall of aortic dissection.

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Huawei, P; Qian, C; Chuan, T; Lei, L; Laing, W; Wenlong, X; Wenzhi, L

2014-02-01

In this research, we will examine the expression of Fibulin-4 in aortic wall to find out its role in aortic dissection development. The samples of aortic wall were obtained from 10 patients operated for acute ascending aortic dissection and five patients for chronic ascending aortic dissection. Another 15 pieces of samples from patients who had coronary artery bypass were as controls. The aortic samples were stained with aldehyde magenta dyeing to evaluate the arrangement of elastic fibers. The Fibulin-4 protein and mRNA expression were both determined by Western blot and realtime quantitative polymerase chain reaction. Compared with the control group, both in acute and chronic ascending aortic dissection, elastic fiber fragments increased and the expression of fibulin-4 protein significantly decreased (P= 0.045 < 0.05). The level of fibulin-4 mRNA decreased in acute ascending aortic dissection (P= 0.034 < 0.05), while it increased in chronic ascending aortic dissection (P=0.004 < 0.05). The increased amounts of elastic fiber fragments were negatively correlated with the expression of fibulin-4 mRNA in acute ascending aortic dissection. In conclusion, in aortic wall of ascending aortic dissection, the expression of fibulin-4 protein decreased and the expression of fibulin-4 mRNA was abnormal. Fibulin-4 may play an important role in the pathogenesis of aortic dissection.

Reoperative Aortic Root Replacement in Patients with Previous Aortic Root or Aortic Valve Procedures

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Byung Kwon Chong

2016-08-01

Full Text Available Background: Generalization of standardized surgical techniques to treat aortic valve (AV and aortic root diseases has benefited large numbers of patients. As a consequence of the proliferation of patients receiving aortic root surgeries, surgeons are more frequently challenged by reoperative aortic root procedures. The aim of this study was to evaluate the outcomes of redo-aortic root replacement (ARR. Methods: We retrospectively reviewed 66 patients (36 male; mean age, 44.5±9.5 years who underwent redo-ARR following AV or aortic root procedures between April 1995 and June 2015. Results: Emergency surgeries comprised 43.9% (n=29. Indications for the redo-ARR were aneurysm (n=12, pseudoaneurysm (n=1, or dissection (n=6 of the residual native aortic sinus in 19 patients (28.8%, native AV dysfunction in 8 patients (12.1%, structural dysfunction of an implanted bioprosthetic AV in 19 patients (28.8%, and infection of previously replaced AV or proximal aortic grafts in 30 patients (45.5%. There were 3 early deaths (4.5%. During follow- up (median, 54.65 months; quartile 1–3, 17.93 to 95.71 months, there were 14 late deaths (21.2%, and 9 valve-related complications including reoperation of the aortic root in 1 patient, infective endocarditis in 3 patients, and hemorrhagic events in 5 patients. Overall survival and event-free survival rates at 5 years were 81.5%±5.1% and 76.4%±5.4%, respectively. Conclusion: Despite technical challenges and a high rate of emergency conditions in patients requiring redo-ARR, early and late outcomes were acceptable in these patients.

ANALYSIS OF TRANSONIC FLOW PAST CUSPED AIRFOILS

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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.

A statistical survey of heat input parameters into the cusp thermosphere

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Moen, J. I.; Skjaeveland, A.; Carlson, H. C.

2017-12-01

Based on three winters of observational data, we present those ionosphere parameters deemed most critical to realistic space weather ionosphere and thermosphere representation and prediction, in regions impacted by variability in the cusp. The CHAMP spacecraft revealed large variability in cusp thermosphere densities, measuring frequent satellite drag enhancements, up to doublings. The community recognizes a clear need for more realistic representation of plasma flows and electron densities near the cusp. Existing average-value models produce order of magnitude errors in these parameters, resulting in large under estimations of predicted drag. We fill this knowledge gap with statistics-based specification of these key parameters over their range of observed values. The EISCAT Svalbard Radar (ESR) tracks plasma flow Vi , electron density Ne, and electron, ion temperatures Te, Ti , with consecutive 2-3 minute windshield-wipe scans of 1000x500 km areas. This allows mapping the maximum Ti of a large area within or near the cusp with high temporal resolution. In magnetic field-aligned mode the radar can measure high-resolution profiles of these plasma parameters. By deriving statistics for Ne and Ti , we enable derivation of thermosphere heating deposition under background and frictional-drag-dominated magnetic reconnection conditions. We separate our Ne and Ti profiles into quiescent and enhanced states, which are not closely correlated due to the spatial structure of the reconnection foot point. Use of our data-based parameter inputs can make order of magnitude corrections to input data driving thermosphere models, enabling removal of previous two fold drag errors.

Wall stress on ascending thoracic aortic aneurysms with bicuspid compared with tricuspid aortic valve.

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Xuan, Yue; Wang, Zhongjie; Liu, Raymond; Haraldsson, Henrik; Hope, Michael D; Saloner, David A; Guccione, Julius M; Ge, Liang; Tseng, Elaine

2018-03-08

Guidelines for repair of bicuspid aortic valve-associated ascending thoracic aortic aneurysms have been changing, most recently to the same criteria as tricuspid aortic valve-ascending thoracic aortic aneurysms. Rupture/dissection occurs when wall stress exceeds wall strength. Recent studies suggest similar strength of bicuspid aortic valve versus tricuspid aortic valve-ascending thoracic aortic aneurysms; thus, comparative wall stress may better predict dissection in bicuspid aortic valve versus tricuspid aortic valve-ascending thoracic aortic aneurysms. Our aim was to determine whether bicuspid aortic valve-ascending thoracic aortic aneurysms had higher wall stresses than their tricuspid aortic valve counterparts. Patients with bicuspid aortic valve- and tricuspid aortic valve-ascending thoracic aortic aneurysms (bicuspid aortic valve = 17, tricuspid aortic valve = 19) greater than 4.5 cm underwent electrocardiogram-gated computed tomography angiography. Patient-specific 3-dimensional geometry was reconstructed and loaded to systemic pressure after accounting for prestress geometry. Finite element analyses were performed using the LS-DYNA solver (LSTC Inc, Livermore, Calif) with user-defined fiber-embedded material model to determine ascending thoracic aortic aneurysm wall stress. Bicuspid aortic valve-ascending thoracic aortic aneurysms 99th-percentile longitudinal stresses were 280 kPa versus 242 kPa (P = .028) for tricuspid aortic valve-ascending thoracic aortic aneurysms in systole. These stresses did not correlate to diameter for bicuspid aortic valve-ascending thoracic aortic aneurysms (r = -0.004) but had better correlation to tricuspid aortic valve-ascending thoracic aortic aneurysms diameter (r = 0.677). Longitudinal stresses on sinotubular junction were significantly higher in bicuspid aortic valve-ascending thoracic aortic aneurysms than in tricuspid aortic valve-ascending thoracic aortic aneurysms (405 vs 329 kPa, P = .023). Bicuspid

Implementing the Comprehensive Unit-Based Safety Program (CUSP) to Improve Patient Safety in an Academic Primary Care Practice.

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Pitts, Samantha I; Maruthur, Nisa M; Luu, Ngoc-Phuong; Curreri, Kimberly; Grimes, Renee; Nigrin, Candace; Sateia, Heather F; Sawyer, Melinda D; Pronovost, Peter J; Clark, Jeanne M; Peairs, Kimberly S

2017-11-01

While there is growing awareness of the risk of harm in ambulatory health care, most patient safety efforts have focused on the inpatient setting. The Comprehensive Unit-based Safety Program (CUSP) has been an integral part of highly successful safety efforts in inpatient settings. In 2014 CUSP was implemented in an academic primary care practice. As part of CUSP implementation, staff and clinicians underwent training on the science of safety and completed a two-question safety assessment survey to identify safety concerns in the practice. The concerns identified by team members were used to select two initial safety priorities. The impact of CUSP on safety climate and teamwork was assessed through a pre-post comparison of results on the validated Safety Attitudes Questionnaire. Ninety-six percent of staff completed science of safety training as part of CUSP implementation, and 100% of staff completed the two-question safety assessment. The most frequently identified safety concerns were related to medications (n = 11, 28.2), diagnostic testing (n = 9, 25), and communication (n = 5, 14). The CUSP team initially prioritized communication and infection control, which led to standardization of work flows within the practice. Six months following CUSP implementation, large but nonstatistically significant increases were found for the percentage of survey respondents who reported knowledge of the proper channels for questions about patient safety, felt encouraged to report safety concerns, and believed that the work setting made it easy to learn from the errors of others. CUSP is a promising tool to improve safety climate and to identify and address safety concerns within ambulatory health care. Copyright © 2017 The Joint Commission. Published by Elsevier Inc. All rights reserved.

Observations of EMIC Waves in the Exterior Cusp Region and in the Nearby Magnetosheath

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Grison, B.; Escoubet, C. P.; Santolik, O.; Lavraud, B.; Cornilleau-Wehrlin, N.

2014-12-01

In the early years (2000-2004) of the mission, Cluster crossed the most distant part of the polar cusps. On 05/01/2002, Cluster enters the distant cusp region on the duskside of the southern hemisphere (inbound). The spacecraft are successively crossing the magnetopause between 19:50 UT (SC4) and 20:15 UT (SC3). The interplanetary conditions during the crossing were stable with a dominant negative By. The magnetometer (FGM) data indicates that the entry into the cusp takes place in a region where the magnetic field lines in the magnetosheath are anti-parallel with the field lines in the magnetosphere. Despite this clear picture, the global encounter is rather complex: one can notice partial magnetopause crossings, magnetic null points, and intense monochromatic waves on both sides of the magnetopause.We investigate electromagnetic ion cyclotron (EMIC) waves observed in the cusp and in the nearby magnetosheath, just before the magnetopause crossing by the spacecraft. Left-handed monochromatic waves observed in the cusp display different duration and frequency (below and above the local proton gyrofrequency) on each spacecraft. Both the Poynting flux of these emissions and the simultaneously recorded ion flows propagate in the same direction - toward the Earth. The wavenumber are determined in two ways: considering the Doppler shift and from direct measurements of the refractive index. We analyze these wave parameters and the local plasma conditions to explain the wave generation process on each side of the magnetopause.

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 (pshoveling trait in the present study population, and this will be valuable in the determination of ethnic origin of an individual. PMID:27135008

Cusp anomalous dimension and rotating open strings in AdS/CFT

Science.gov (United States)

Espíndola, R.; García, J. Antonio

2018-03-01

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.

Aortic Annular Enlargement during Aortic Valve Replacement

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Selman Dumani

2016-09-01

Full Text Available In the surgery of aortic valve replacement is always attempted, as much as possible, to implant the larger prosthesis with the mains goals to enhance the potential benefits, to minimise transvalvular gradient, decrease left ventricular size and avoid the phenomenon of patient-prosthesis mismatch. Implantation of an ideal prosthesis often it is not possible, due to a small aortic annulus. A variety of aortic annulus enlargement techniques is reported to avoid patient-prosthesis mismatch. We present the case that has submitted four three times open heart surgery. We used Manouguian technique to enlarge aortic anulus with excellent results during the fourth time of surgery.

First records of talon cusps on baboon maxillary incisors argue for standardizing terminology and prompt a hypothesis of their formation.

Science.gov (United States)

Heaton, Jason L; Pickering, Travis Rayne

2013-12-01

Dental characters can provide vital clues for understanding intra- and intertaxonomic morphological variation and its underlying genetic and environmental components. However, the unambiguous identification of particular traits and their comparative study is often confounded by lack of consistent terminology in the relevant literature. This difficulty is exacerbated when the etiologies are not completely understood, as is the case with talon cusps. To date, research on talon cusps has focused on modern humans. In many instances, descriptions of talon cusps appear in clinical case studies focusing on their treatment and removal. What is lacking in those discussions, though, is a comparative framework, in which the occurrence of talon cusps in nonhuman primates, and possibly other mammals, is established and understood. Here, we report on a taloned upper central incisor of a wild baboon (Papio hamadryas ursinus) from South Africa. The anomalous incisor of this individual includes an exaggerated accessory cusp diagnosed as a Type II talon. Microcomputed tomographic and radiographic analyses show that the taloned cusp possesses enamel, dentin, and pulp. In addition, we identified an unclassifiable talon cusp on a central maxillary incisor of a baboon skull housed in the Smithsonian Institution's Natural History Museum collection. Our observations of talon cusps on baboon incisors demonstrate that, with regard to this phenomenon, systematic study of nonhuman primates is much needed, along with a consistent use of terminology in the anatomical and anthropological literature. Finally, we present a hypothesis of the formation of talon cusps on mammalian incisors. Copyright © 2013 Wiley Periodicals, Inc.

Effects of cusped field thruster on the performance of drag-free control system

Science.gov (United States)

Cui, K.; Liu, H.; Jiang, W. J.; Sun, Q. Q.; Hu, P.; Yu, D. R.

2018-03-01

With increased measurement tasks of space science, more requirements for the spacecraft environment have been put forward. Those tasks (e.g. the measurement of Earth's steady state gravity field anomalies) lead to the desire for developing drag-free control. Higher requirements for the thruster performance are made due to the demand for the drag-free control system and real-time compensation for non-conservative forces. Those requirements for the propulsion system include wide continuous throttling ability, high resolution, rapid response, low noise and so on. As a promising candidate, the cusped field thruster has features such as the high working stability, the low erosion rate, a long lifetime and the simple structure, so that it is chosen as the thruster to be discussed in this paper. Firstly, the performance of a new cusped field thruster is tested and analyzed. Then a drag-free control scheme based on the cusped field thruster is designed to evaluate the performance of this thruster. Subsequently, the effects of the thrust resolution, transient response time and thrust uncertainty on the controller are calculated respectively. Finally, the performance of closed-loop system is analyzed, and the simulation results verify the feasibility of applying cusped field thruster to drag-free flight in the space science measurement tasks.

Cusps in KL→3π decays

International Nuclear Information System (INIS)

Bissegger, M.; Fuhrer, A.; Gasser, J.; Kubis, B.; Rusetsky, A.

2008-01-01

The pion mass difference generates a pronounced cusp in K→3π decays, the strength of which is related to the ππ S-wave scattering lengths. We apply an effective field theory framework developed earlier to evaluate the amplitudes for K L →3π decays in a systematic manner, where the strictures imposed by analyticity and unitarity are respected automatically. The amplitudes for the decay η→3π are also given

The Effect of Composite Thickness on the Stress Distribution Pattern of Restored Premolar Teeth with Cusp Reduction.

Science.gov (United States)

Panahandeh, Narges; Torabzadeh, Hassan; Ziaee, Nargess; Mahdian, Mina; Tootiaee, Bahman; Ghasemi, Amir

2017-07-01

Different thicknesses of restorative material can alter the stress distribution pattern in remaining tooth structure. The assumption is that a thicker composite restoration will induce a higher fracture resistance. Therefore, the present study evaluated the effect of composite thickness on stress distribution in a restored premolar with cusp reduction. A 3D solid model of a maxillary second premolar was prepared and meshed. MOD cavities were designed with different cusp reduction thicknesses (0, 0.5, 1, 1.5, 2.5 mm). Cavities were restored with Valux Plus composite. They were loaded with 200 N force on the occlusal surface in the direction of the long axis. Von Mises stresses were evaluated with Abaqus software. Stress increased from occlusal to gingival and was maximum in the cervical region. The stressed area in the palatal cusp was more than that of the buccal cusp. Increasing the thickness of composite altered the shear stress to compressive stress in the occlusal area of the teeth. The model with 2.5 mm cusp reduction exhibited the most even stress distribution. © 2015 by the American College of Prosthodontists.

Complementary role of cardiac CT in the assessment of aortic valve replacement dysfunction

Science.gov (United States)

Moss, Alastair J; Dweck, Marc R; Dreisbach, John G; Williams, Michelle C; Mak, Sze Mun; Cartlidge, Timothy; Nicol, Edward D; Morgan-Hughes, Gareth J

2016-01-01

Aortic valve replacement is the second most common cardiothoracic procedure in the UK. With an ageing population, there are an increasing number of patients with prosthetic valves that require follow-up. Imaging of prosthetic valves is challenging with conventional echocardiographic techniques making early detection of valve dysfunction or complications difficult. CT has recently emerged as a complementary approach offering excellent spatial resolution and the ability to identify a range of aortic valve replacement complications including structural valve dysfunction, thrombus development, pannus formation and prosthetic valve infective endocarditis. This review discusses each and how CT might be incorporated into a multimodal cardiovascular imaging pathway for the assessment of aortic valve replacements and in guiding clinical management. PMID:27843568

Studies of small-scale plasma inhomogeneities in the cusp ionosphere using sounding rocket data

Science.gov (United States)

Chernyshov, Alexander A.; Spicher, Andres; Ilyasov, Askar A.; Miloch, Wojciech J.; Clausen, Lasse B. N.; Saito, Yoshifumi; Jin, Yaqi; Moen, Jøran I.

2018-04-01

Microprocesses associated with plasma inhomogeneities are studied on the basis of data from the Investigation of Cusp Irregularities (ICI-3) sounding rocket. The ICI-3 rocket is devoted to investigating a reverse flow event in the cusp F region ionosphere. By numerical stability analysis, it is demonstrated that inhomogeneous-energy-density-driven (IEDD) instability can be a mechanism for the excitation of small-scale plasma inhomogeneities. The Local Intermittency Measure (LIM) method also applied the rocket data to analyze irregular structures of the electric field during rocket flight in the cusp. A qualitative agreement between high values of the growth rates of the IEDD instability and the regions with enhanced LIM is observed. This suggests that IEDD instability is connected to turbulent non-Gaussian processes.

Valve-sparing aortic root replacement and aortic valve repair in a patient with acromegaly and aortic root dilatation

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Karel Van Praet

2015-07-01

Full Text Available Aortic regurgitation and dilatation of the aortic root and ascending aorta are severe complications of acromegaly. The current trend for management of an aortic root aneurysm is valve-sparing root replacement as well as restoring the diameter of the aortic sinotubular junction (STJ and annulus. Our case report supports the recommendation that in patients with acromegaly, severe aortic root involvement may indicate the need for surgery.

Enabling Ring-Cusp Ion Thruster Technology for NASA Missions

Data.gov (United States)

National Aeronautics and Space Administration — ESA is flying T6 Kaufman ion thrusters on the BepiColombo Mission to Mercury in 2018. They are planning to develop a longer life, higher performing, 30-cm ring-cusp...

Magnetic field and electric currents in the vicinity of polar cusps as inferred from Polar and Cluster data

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N. A. Tsyganenko

2009-04-01

Full Text Available A detailed statistical study of the magnetic structure of the dayside polar cusps is presented, based on multi-year sets of magnetometer data of Polar and Cluster spacecraft, taken in 1996–2006 and 2001–2007, respectively. Thanks to the dense data coverage in both Northern and Southern Hemispheres, the analysis spanned nearly the entire length of the cusps, from low altitudes to the cusp "throat" and the magnetosheath. Subsets of data falling inside the polar cusp "funnels" were selected with the help of TS05 and IGRF magnetic field models, taking into account the dipole tilt and the solar wind/IMF conditions. The selection funnels were shifted within ±10° of SM latitude around the model cusp location, and linear regression parameters were calculated for each sliding subset, further divided into 10 bins of distance in the range 2≤R≤12 RE, with the following results. (1 Diamagnetic depression, caused by the penetrated magnetosheath plasma, becomes first visible at R~4–5 RE, rapidly deepens with growing R, peaks at R~6–9 RE, and then partially subsides and widens in latitude at the cusp's outer end. (2 The depression peak is systematically shifted poleward (by ~2° of the footpoint latitude with respect to the model cusp field line, passing through the min{|B|} point at the magnetopause. (3 At all radial distances, clear and distinct peaks of the correlation between the local By and By(IMF and of the corresponding proportionality coefficient are observed. A remarkably regular variation of that coefficient with R quantitatively confirms the field-aligned geometry of the cusp currents associated with the IMF By, found in earlier observations.

Aortic valve bypass

DEFF Research Database (Denmark)

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

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). ...

Axis-encircling electron beam generation using a smooth magnetic cusp for gyrodevices

International Nuclear Information System (INIS)

He, W.; Whyte, C. G.; Rafferty, E. G.; Cross, A. W.; Phelps, A. D. R.; Ronald, K.; Young, A. R.; Robertson, C. W.; Speirs, D. C.; Rowlands, D. H.

2008-01-01

The generation of an annular-shaped axis-encircling electron beam using a smooth magnetic cusp was studied through numerical simulations and experiments for harmonic operation of a gyrodevice. Two magnetic coils were used to form a magnetic cusp located just downstream from the velvet cathode of an accelerator diode. An electron beam of current 34 A and voltage 130 kV with an adjustable velocity ratio α up to 1.2 was fully transported to the downstream uniform magnetic field region and used to drive a gyrotron traveling wave amplifier into saturation

Aortic compliance in patients with aortic regurgitation. Evaluation with magnetic resonance imaging

International Nuclear Information System (INIS)

Murai, Sachiko; Hamada, Seiki; Ueguchi, Takashi

2005-01-01

The purpose of this study was to assess by means of cine magnetic resonance imaging (MRI) aortic compliance before and after aortic valve replacement (AVR with SJM (St. Jude Medical, St paul, MN) valve) in patients with aortic regurgitation (AR). Two groups (healthy controls and patients with severe isolated AR) of 10 subjects each were included in this study. Cine MRI was performed at three locations of the aorta, and aortic compliance was calculated by dividing the maximum change in the aortic area by pulse pressure. Cine MRI is useful to assess abnormalities of aortic compliance in patients with AR. Compared with the control group, aortic compliance in the AR group was significantly less in the ascending aorta (p<0.05), decreasing in order of aortic location. After AVR, aortic compliance improved for all locations. Cine MRI enables assessment of aortic biophysical properties such as a compliance for evaluating the progression of AR and the efficacy of treatment. (author)

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

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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

Acute Type II Aortic Dissection with Severe Aortic Regurgitation and Chronic Descending Aortic Dissection in Pregnant Patient with Marfan Syndrome.

Science.gov (United States)

Lee, Seok-Soo; Jung, Tae-Eun; Lee, Dong Hyup

2012-12-01

Aortic dilatation and dissection are severe complications during pregnancy that can be fatal to both the mother and the fetus. The risks of these complications are especially high in pregnant patients with Marfan syndrome; however, incidents of descending aortic dissection are very rare. This case report involves a successful Bentall procedure for and recovery from a rare aortic dissection in a pregnant Marfan patient who developed acute type II aortic dissection with severe aortic regurgitation and chronic descending aortic dissection immediately after Cesarean section. Regular follow-up will be needed to monitor the descending aortic dissection.

Aortic root replacement after previous surgical intervention on the aortic valve, aortic root, or ascending aorta.

Science.gov (United States)

Kirsch, E W Matthias; Radu, N Costin; Mekontso-Dessap, Armand; Hillion, Marie-Line; Loisance, Daniel

2006-03-01

Aortic root replacement after a previous operation on the aortic valve, aortic root, or ascending aorta remains a major challenge. Records of 56 consecutive patients (44 men; mean age, 56.4 +/- 13.6 years) undergoing reoperative aortic root replacement between June 1994 and June 2005 were reviewed retrospectively. Reoperation was performed 9.4 +/- 6.7 years after the last cardiac operation. Indications for reoperation were true aneurysm (n = 14 [25%]), false aneurysm (n = 10 [18%]), dissection or redissection (n = 9 [16%]), structural or nonstructural valve dysfunction (n = 10 [18%]), prosthetic valve-graft infection (n = 12 [21%]), and miscellaneous (n = 1 [2%]). Procedures performed were aortic root replacement (n = 47 [84%]), aortic root replacement plus mitral valve procedure (n = 5 [9%]), and aortic root replacement plus arch replacement (n = 4 [7%]). In 14 (25%) patients coronary artery bypass grafting had to be performed unexpectedly during the same procedure or immediately after the procedure to re-establish coronary perfusion. Hospital mortality reached 17.9% (n = 10). Multivariate logistic regression analysis revealed the need for unplanned perioperative coronary artery bypass grafting as the sole independent risk factor for hospital death (P = .005). Actuarial survival was 83.8% +/- 4.9% at 1 month, 73.0% +/- 6.3% at 1 year, and 65.7% +/- 9.0% at 5 years after the operation. One patient had recurrence of endocarditis 6.7 months after the operation and required repeated homograft aortic root replacement. Reoperative aortic root replacement remains associated with a high postoperative mortality. The need to perform unplanned coronary artery bypass grafting during reoperative aortic root replacement is a major risk factor for hospital death. The optimal technique for coronary reconstruction in this setting remains to be debated.

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

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M. Bouhram

2003-08-01

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

Mechanical interactions of cuspal-coverage designs and cement thickness in a cusp-replacing ceramic premolar restoration: a finite element study.

Science.gov (United States)

Chang, Yen-Hsiang; Lin, Wen-Hsueng; Kuo, Wen-Chieh; Chang, Chia-Yu; Lin, Chun-Li

2009-04-01

The aim of this study was to investigate the biomechanical interactions between cuspal preparation designs and cement thickness in a cusp-replacing ceramic premolar restoration. The cavity was designed in a typical MODP (mesial-occlusal-distal- palatal) restoration failure shape when the palatal cusp has been lost. Twelve 3D finite element (FE) models with four cavity preparations (without coverage and with buccal cuspal coverage in 1.0, 1.5 and 2.0 mm reducing in cuspal height) and three cement thicknesses (50, 100 and 150 microm) were constructed to perform the simulations. The results indicated that enamel and cement stresses in designs with no buccal cusp replacement or a 1.0 mm thick buccal cusp replacement were higher than the designs with 1.5 and 2.0 mm thick replacement. No apparent differences were found in the dentin, enamel, and cement stresses based on cement thicknesses of 50, 100, or 150 microm. This study concluded that when cusp replacement is indicated, reduction of the buccal cusp by 1.5 mm at least could reduce stress.

Directional tip control technique for optimal stent graft alignment in angulated proximal aortic landing zones

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Toshio Takayama, MD, PhD

2017-06-01

Full Text Available Angulated anatomy in the aorta, such as tortuous infrarenal aortic necks or steep aortic arches, is a significant challenge for endovascular aortic repair because it often causes inadequate sealing and fixation, which may lead to treatment failure. We have developed a technique using off-the-shelf equipment to precisely control the deployment of stent grafts in challenging landing zones. The key of this technique is to create a through-and-through wire between two access sites and to use a guiding device over the wire. This technique is best used with stent grafts without nose cones. We present an endovascular aneurysm repair case and a thoracic endovascular aortic repair case with challenging proximal landing zones treated by this technique. In both cases, technical success was attained, and follow-up imaging demonstrated well-aligned stent grafts. Our directional tip control technique is easy and effective. It can be a good technical solution for endovascular aortic treatment in angulated anatomy.

Apex Dips of Experimental Flux Ropes: Helix or Cusp?

Energy Technology Data Exchange (ETDEWEB)

Wongwaitayakornkul, Pakorn; Haw, Magnus A.; Bellan, Paul M. [Applied Physics, California Institute of Technology, Pasadena, CA 91125 (United States); Li, Hui [Theoretical Division, Los Alamos National Laboratory, Mail Stop B227, Los Alamos, NM 87545 (United States); Li, Shengtai, E-mail: pwongwai@caltech.edu, E-mail: mhaw@caltech.edu [Mathematical Modeling and Analysis, Los Alamos National Laboratory, Mail Stop B284, Los Alamos, NM 87545 (United States)

2017-10-20

We present a new theory for the presence of apex dips in certain experimental flux ropes. Previously such dips were thought to be projections of a helical loop axis generated by the kink instability. However, new evidence from experiments and simulations suggest that the feature is a 2D cusp rather than a 3D helix. The proposed mechanism for cusp formation is a density pileup region generated by nonlinear interaction of neutral gas cones emitted from fast-gas nozzles. The results indicate that density perturbations can result in large distortions of an erupting flux rope, even in the absence of significant pressure or gravitational forces. The density pileup at the apex also suppresses the m = 1 kink mode by acting as a stationary node. Consequently, more accurate density profiles should be considered when attempting to model the stability and shape of solar and astrophysical flux ropes.

Delayed Presentation of a Giant Ascending Aortic Aneurysm following Aortic Valve Replacement

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Tugrul Göncü

2009-01-01

Full Text Available Giant ascending aortic aneurysm formation following aortic valve replacement is rare. A 28-year-old man who underwent aortic valve replacement with a prosthetic valve for aortic regurgitation secondary to congenital bicuspid aortic valve about 10 years ago was diagnosed with a giant ascending aortic aneurysm about 16 cm in diameter in follow-up. The aneurysm was resected leaving the functional old mechanical prosthesis in place and implanted a 34-mm Hemashield woven graft, associated with the left and right coronary artery button implantation. Histological findings of the aortic aneurysm wall showed cystic medial necrosis. The postoperative course was uneventful and postoperative examination demonstrated good surgical results.

Manifolds with cusps of rank one spectral theory and L2-index theorem

CERN Document Server

Müller, Werner

1987-01-01

The manifolds investigated in this monograph are generalizations of (Mathematical Physics and Mathematics)-rank one locally symmetric spaces. In the first part of the book the author develops spectral theory for the differential Laplacian operator associated to the so-called generalized Dirac operators on manifolds with cusps of rank one. This includes the case of spinor Laplacians on (Mathematical Physics and Mathematics)-rank one locally symmetric spaces. The time-dependent approach to scattering theory is taken to derive the main results about the spectral resolution of these operators. The second part of the book deals with the derivation of an index formula for generalized Dirac operators on manifolds with cusps of rank one. This index formula is used to prove a conjecture of Hirzebruch concerning the relation of signature defects of cusps of Hilbert modular varieties and special values of L-series. This book is intended for readers working in the field of automorphic forms and analysis on non-compact Ri...

Study of a new cusp field for an 18 GHz ECR ion source

Science.gov (United States)

Rashid, M. H.; Nakagawa, T.; Goto, A.; Yano, Y.

2007-08-01

A feasibility study was performed to generate new sufficient mirror cusp magnetic field (CMF) by using the coils of the existing room temperature traditional 18 GHz electron cyclotron resonance ion source (ECRIS) at RIKEN. The CMF configuration was chosen because it contains plasma superbly and no multipole magnet is needed to make the contained plasma quiescent with no magneto-hydrodynamic (MHD) instability and to make the system cost-effective. The least magnetic field, 13 kG is achieved at the interior wall of the plasma chamber including the point cusps (PC) on the central axis and the ring cusp (RC) on the mid-plane. The mirror ratio calculation and electron simulation were done in the computed CMF. It was found to contain the electrons for longer time than in traditional field. It is proposed that a powerful CMF ECRIS can be constructed, which is capable of producing intense highly charged ion (HCI) beam for light and heavy elements.

Evidence for storm-time ionospheric ion precipitation in the cusp with magnetosheath energy

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H. Stenuit

2004-04-01

Full Text Available We present evidence for a sporadic precipitation into the north polar cusp of ionospheric O+ and He+ ions accelerated up to the magnetosheath flow speed during a magnetic storm. This is deduced from data obtained on board the Interball-Auroral satellite showing that the energy/charge ratios of the H+, He++, He+ and O+ populations are similar to those of ion masses. These measurements pertain to a very disturbed magnetic period. A storm was in progress with a Dst reaching -149nT during the cusp measurements, while the AE index reached values higher than 1000nT. This result is discussed in terms of ion circulation from the magnetosphere to the magnetosheath and back to the magnetosphere. We suggest that the acceleration of O+ and He+ ions up to a magnetosheath-like velocity is directly linked to the large By component of the IMF.Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; magnetosheath; storms and substorms

Studies on the effect of radio frequency field in a cusp-type charge separation device for direct energy conversion

International Nuclear Information System (INIS)

Hamabe, Masaki; Izawa, Hiroaki; Takeno, Hiromasa; Nakamoto, Satoshi; Ichimura, Kazuya; Nakashima, Yousuke

2016-01-01

In D- 3 He fusion power generation, an application of direct energy conversion is expected in which separation of charged particles is necessary. A cusp-type direct energy converter (CuspDEC) was proposed as a charge separation device, but its performance was degraded for a high density plasma. The goal of the present study is to establish an additional method to assist charge separation by using a nonlinear effect of a radio frequency (rf) electric field. Following to the previous study, we experimentally examine the effect of an rf field to electron motion in a CuspDEC device. Two ring electrodes were newly installed in a CuspDEC simulator and the current flowing into the electron collector located in the line cusp region was measured on an rf field application. The significant variation in the current was found, and an improvement of the charge separation can be expected by using the phenomenon appropriately. (author)

THE CUSP/CORE PROBLEM AND THE SECONDARY INFALL MODEL

International Nuclear Information System (INIS)

Del Popolo, A.

2009-01-01

We study the cusp/core problem using a secondary infall model that takes into account the effect of ordered and random angular momentum, dynamical friction, and baryons adiabatic contraction (AC). The model is applied to structures on galactic scales (normal and dwarfs spiral galaxies) and on clusters of galaxies scales. Our analysis suggest that angular momentum and dynamical friction are able, on galactic scales, to overcome the competing effect of AC eliminating the cusp. The slope of density profile of inner halos flattens with decreasing halo mass and the profile is well approximated by a Burkert's profile. In order to obtain the Navarro-Frenk-White (NFW) profile, starting from the profiles obtained from our model, the magnitude of angular momentum and dynamical friction must be reduced with respect to the values predicted by the model itself. The rotation curves of four lower sideband galaxies from Gentile et al. are compared to the rotation curves obtained by the model in the present paper obtaining a good fit to the observational data. The time evolution of the density profile of a galaxy of 10 8 -10 9 M sun shows that after a transient steepening, due to the AC, the density profile flattens to α ≅ 0. On cluster scales we observe a similar evolution of the dark matter (DM) density profile but in this case the density profile slope flattens to α ≅ 0.6 for a cluster of ≅10 14 M sun . The total mass profile, differently from that of DM, shows a central cusp well fitted by an NFW model.

Cost estimate for electrostatically plugged cusp reactor

International Nuclear Information System (INIS)

Dolan, T.J.

1977-01-01

A preliminary design of an electrostatically plugged cusp reactor was presented in (UCRL-52142(1976)). The capital costs of the various components of this reactor are estimated and totaled for two different blanket configurations: one having an energy multiplication factor M = 1.2, and the other having M = 1.68. The unoptimized direct capital costs for these cases are found to be about 1400 and 950 $/kWe, respectively

The bicuspid aortic valve and its relation to aortic dilation

Directory of Open Access Journals (Sweden)

Shi-Min Yuan

2010-01-01

Full Text Available BACKGROUND: A bicuspid aortic valve (BAV is a common congenital heart disease, which affects 1-2% of the population. However, the relationship between BAVs and aortic dilation has not been sufficiently elucidated. METHODS: A total of 241 BAV patients who were referred to this hospital for cardiac surgey over a 4.75-year period were included in this study. In addition to the clinical characteristics of the included patients, the morphological features of the aortic valve and aorta, the length of the left main coronary artery, and the laboratory findings (the coagulation and hematological parameters as well as the total cholesterol concentration were determined and compared with those of the tricuspid aortic valve (TAV patients. RESULTS: The BAV patients were younger than the TAV patients for a valve surgery in the last 3 months of the study period. The BAV patients were predominantly male. Most of the BAVs that were surgically treated were stenotic, regurgitant, or combined, and only 19 (7.88% were normally functioning valves. According to echocardiography or operative records, 148 (78.31% were type A, 31 (16.40% were type B, and 10 (5.29% were type C. The left main coronary artery was much shorter in the BAV patients than it was in the TAV patients. There was no significant difference between BAV and TAV patients in the total cholesterol concentrations; whereas differences were noted between patients receiving lipid-lowering therapy and those not receiving lipid-lowering therapy. The dimensions of the aortic root, sinotubular junction, and ascending aorta were beyond normal limits, while they were significantly smaller in the BAV patients than in the TAV patients. They were also much smaller in patients receiving statin therapy than those not receiving statin therapy in both groups. Moreover, the aortic dilation in the BAV group was found to be significantly associated with patient age. CONCLUSIONS: The BAV patients developed aortic wall and

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.

Aortic root reimplantation procedure: a new milestone in aortic valve-sparing operations

Directory of Open Access Journals (Sweden)

А. М. Чернявский

2016-08-01

Full Text Available Aim: Emphasis in this study was placed on clinical and functional assessment of a modified "Florida Sleeve" procedure during surgical correction of ascending aorta aneurysms with concomitant aortic insufficiency.Methods: 32 patients with an aneurysm of the ascending aorta and aortic insufficiency underwent a modified "Florida Sleeve" procedure. The average follow-up was 17 (0-60 months. The average age of patients was 57±13 (23-73 years 56±13 years.Results: The expected 4-year cumulative survival rate was 84.3%. Overall freedom from aortic insufficiency in the late period was 88.9%. Median aortic regurgitation was 1+ (1; 2. Long-term follow-up revealed no valve-associated complications.Conclusion: The aortic root reimplantation procedure enables optimal correction of the existing lesions of the aortic root without performing aortic valve replacement and demonstrates stable clinical and functional outcomes in the long-term period.Key words: aortic aneurysm; aortic valve; valve-sparing operations.FundingThe study had no sponsorship.Conflict of interestThe authors declare no conflict of interest.

Acute Type II Aortic Dissection with Severe Aortic Regurgitation and Chronic Descending Aortic Dissection in Pregnant Patient with Marfan Syndrome

OpenAIRE

Lee, Seok-Soo; Jung, Tae-Eun; Lee, Dong Hyup

2012-01-01

Aortic dilatation and dissection are severe complications during pregnancy that can be fatal to both the mother and the fetus. The risks of these complications are especially high in pregnant patients with Marfan syndrome; however, incidents of descending aortic dissection are very rare. This case report involves a successful Bentall procedure for and recovery from a rare aortic dissection in a pregnant Marfan patient who developed acute type II aortic dissection with severe aortic regurgitat...

Aortic valve replacement for aortic stenosis caused by alkaptonuria.

Science.gov (United States)

Hiroyoshi, Junko; Saito, Aya; Panthee, Nirmal; Imai, Yasushi; Kawashima, Dai; Motomura, Noboru; Ono, Minoru

2013-03-01

We report a case of aortic stenosis associated with ochronosis in a 70-year-old man who underwent biologic aortic valve replacement. Intraoperative findings included ochronosis of a severely calcified pigmented aortic valve along with pigmentation of the intima of the aorta. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

[Thymic carcinoma involving aortic arch; report of a case].

Science.gov (United States)

Noriyuki, Toshio; Hamamoto, M; Takazawa, Y; Katoh, K; Hashimoto, M; Kuranishi, F; Nakahara, M; Fukuda, T; Ishizaki, Y; Okuda, H; Akimoto, E; Yonehara, S

2009-05-01

Adenocarcinoma of the thymus is a very rare malignant tumor. The standard treatment for advanced thymic carcinoma has not yet been established, and the prognosis is poor. We report a case of thymic carcinoma that involving the aortic arch and the innominate vein. A 78-year-old woman was admitted to our hospital complaining of hoarseness in April 2007. The computed tomography (CT) scan showed an anterior mediastinal tumor contiguous to the aortic arch and the innominate vein with swelling lymphnodes. Microspcopic examinations of specimens obtained by CT-guided needle biopsy revealed poorly differenciated adenocarcinoma. The carcinoembryonic antigen (CEA) level of serum elevated at 54.9 ng/ml. Thymic carcinoma was diagnosed. The chemoradiotherapy [concurrent, carboplatin (CBDCA) + paclitaxel(TXL)-->vinorelbine (NVB), 60 Gy] was performed, but the effect of the therapy was limited. The resection of the tumor with a part of aortic arch and other peripheral tissues was performed in Augast 2007. The postoperative course was uneventful and the CEA level of serum lowered to the normal. She was discharged 30 days after surgery.

Steam-deformed Judkins-left guiding catheter with use of the GuideLiner(®) catheter to deliver stents for anomalous right coronary artery.

Science.gov (United States)

Kuno, Toshiki; Fujisawa, Taishi; Yamazaki, Hiroyuki; Motoda, Hiroyuki; Kodaira, Masaki; Numasawa, Yohei

2015-01-01

Percutaneous coronary intervention for anomalous right coronary artery (RCA) originating from the left coronary cusp is challenging because of our current inability to coaxially engage the guiding catheter. We report a case of an 88-year-old woman with non-ST segment elevation myocardial infarction, with an anomalous RCA origin. Using either the Judkins-Left catheter or Amplatz-Left catheter was difficult because of RCA ostium tortuosity. Thus, we used steam to deform the Judkins-Left catheter, but back-up support was insufficient to deliver the stent. We used GuideLiner®, a novel pediatric catheter with rapid exchange/monorail systems, to enhance back-up support. We were able to successfully stent with both the deformed Judkins-Left guiding catheter and GuideLiner® for an anomalous RCA origin.

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.

The polar cusp from a particle point of view: A statistical study based on Viking data

International Nuclear Information System (INIS)

Aparicio, B.; Thelin, B.; Lundin, R.

1991-01-01

The authors present results from the particle measurements made on board the Viking satellite. For the period of interest the Viking orbits covered at high latitudes the whole dayside sector. Data from the Viking V-3 particle experiment acquired during the Polar Region Outer Magnetospheric International Study period have been used to study the extension of the cusp and cleft in magnetic local time and invariant latitude, and furthermore, their dependence on solar wind and interplanetary magnetic field parameters. The study is limited to the MLT range from 0900 to 1500 and to invariant latitudes (ILAT) from 74 degree to 82 degree. This region is divided into bins of size. The authors concentrated on the region where magnetosheath solar wind plasma penetrates more directly into the magnetosphere and is measured at Viking altitudes. This region is called the cusp proper, to be distinguished from a broader region denoted the cleft, where more energetic particles are observed. Statistically, they find the cusp proper to extend from invariant latitudes of 75 degree to 82 degree and magnetic local times from 0930 to 1400 MLT. The width in ILAT is found to be on average ∼2 degree and in MLT ∼2 hours. It is shown that a clear correlation exists between the densities in the cusp proper calculated from the Viking V-3 experiment in the cusp proper and those in the solar wind calculated from IMP 8 measurements. It is also shown that the position of the cusp proper in MLT depends on the sense of the By component of the interplanetary magnetic field (IMF By), giving a well-defined displacement of the region of maximum occurrence toward earlier MLTs for IMF By 0

Surgery for acute Type I aortic dissection without resection of supra-aortic entry sites leads to unfavourable aortic remodelling.

Science.gov (United States)

Heo, Woon; Song, Suk-Won; Lee, Kwang-Hun; Lee, Shin-Young; Kim, Tae-Hoon; Baek, Min-Young; Yoo, Kyung-Jong

2018-01-29

This study aimed to evaluate the impact of remnant re-entries in arch branches on postoperative change in the aortic arch and descending aortic diameters and the rate of major adverse aortic events. Between January 2010 and December 2016, 249 patients underwent surgery for acute Type I aortic dissection. Patients who underwent total arch replacement, had Marfan syndrome or had intramural haematoma were excluded. Seventy-two patients with predischarge and follow-up computed tomography scans were enrolled. Patients with and without re-entries in the arch branches after surgery were assigned to the supra-aortic entry (SAE, n = 21) and no supra-aortic entry (n = 51) groups, respectively. Diameters were measured at 7 levels: the innominate artery, left common carotid artery, left subclavian artery, 20 mm distal to the left subclavian artery, pulmonary artery bifurcation, coeliac axis and maximal diameter of the descending thoracic aorta. Growth rates at the levels of the pulmonary artery bifurcation and 20 mm distal to the left subclavian artery were significantly higher in the SAE group than in the no supra-aortic entry group. The rate of freedom from major adverse aortic events (annual growth >5 mm or maximal diameter of the descending thoracic aorta >50 mm) at 5 years was significantly higher in the no supra-aortic entry group than in the SAE group. Remnant SAE leads to unfavourable aortic remodelling after acute Type I aortic dissection repair. © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Elimination of cusps in dimension 4 and its applications

NARCIS (Netherlands)

Behrens, S.|info:eu-repo/dai/nl/380140217; Hayano, Kenta

2016-01-01

We study a class of homotopies between maps from 4-manifolds to surfaces which we call cusp merges. These homotopies naturally appear in the uniqueness problems for certain pictorial descriptions of 4-manifolds derived from maps to the 2-sphere (for example, broken Lefschetz fibrations, wrinkled

Role of multiple cusps in tooth fracture.

Science.gov (United States)

Barani, Amir; Bush, Mark B; Lawn, Brian R

2014-07-01

The role of multiple cusps in the biomechanics of human molar tooth fracture is analysed. A model with four cusps at the bite surface replaces the single dome structure used in previous simulations. Extended finite element modelling, with provision to embed longitudinal cracks into the enamel walls, enables full analysis of crack propagation from initial extension to final failure. The cracks propagate longitudinally around the enamel side walls from starter cracks placed either at the top surface (radial cracks) or from the tooth base (margin cracks). A feature of the crack evolution is its stability, meaning that extension occurs steadily with increasing applied force. Predictions from the model are validated by comparison with experimental data from earlier publications, in which crack development was followed in situ during occlusal loading of extracted human molars. The results show substantial increase in critical forces to produce longitudinal fractures with number of cuspal contacts, indicating a capacity for an individual tooth to spread the load during mastication. It is argued that explicit critical force equations derived in previous studies remain valid, at the least as a means for comparing the capacity for teeth of different dimensions to sustain high bite forces. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acute Aortic Arch Perforation During Transcatheter Aortic Valve Replacement in Bicuspid Aortic Stenosis and a Gothic Aortic Arch

DEFF Research Database (Denmark)

Millan-Iturbe, Oscar; Sawaya, Fadi J.; Bieliauskas, Gintautas

2017-01-01

AS because of its unique anatomic features. This case report describes an acute aortic perforation during delivery of a transcatheter heart valve to treat a severe bicuspid AS with a “gothic aortic arch”; more careful evaluation of the preprocedural multislice computed tomographic scan would have unveiled...

On the energy shift of the ECC cusp. Does the shift really exist?

International Nuclear Information System (INIS)

Barrachina, R.O.; Sarkadi, L.

2004-01-01

Full text: The cusplike 'electron capture to the continuum' (ECC) peak appearing in the spectrum of the forward emitted electrons in ion-atom collisions is generally thought to be a divergence. The peak is centered at electron velocity that matches that of the projectile. Recently Illescas et al. [1] claimed, however, that 'the cusp is not a divergence smoothed by the experiment, and is slightly shifted from the impact-velocity value'. In a subsequent work Shah et al. [2] measured the ECC cusp for collisions of 10- and 20- keV protons with H2 and He, and found that the peak was indeed shifted to a velocity below its expected position. Their classical trajectory Monte Carlo (CTMC) calculations reproduced the observation well. In the present work we demonstrate by our CTMC calculations (made for the case of 20-keV protons on He) that the intensity, width and position of the ECC cusp do depend on the experimental conditions by which the electrons are detected (first of all, the acceptance angle of the electron spectrometer). We also present experimental data for this collision system. While the latter data are well reproduced by our CTMC calculations, neither the theoretical results, nor the experimental data of the present work support of the findings of Shah et al. [2]. At the same time, analyzing the problem in the framework of the general final-state interaction theory of cusp formation [3], we concluded that 'rigorously' speaking Shah et al. [2] are right when they state that the ECC cusp is not a divergence. The divergence is smeared out by the scattering of the projectile. However, this effect is negligibly small at the lowest energy that was considered in their paper, 10 keV. At this impact energy the projectile motion is smeared within an angular region Δθ th ∼ 0.06 deg, which is much smaller than the acceptance angle of the experiment, Δθ exp ∼ 1.5 deg

Cusp/cleft region as observed by the Viking UV imager

International Nuclear Information System (INIS)

Garbe, G.P.; Murphree, J.S.; Cogger, L.L.; Woch, J.

1993-01-01

The authors report data taken by the Viking satellite at mid-altitudes (11,000-13,000 km) during northern hemispheric crossings of the cusp/cleft region. Particle signatures were used to divide the region into different categories. Data was looked at from the ultraviolet imager and particle diagnostics, when available. The authors discuss in detail two cases of crossing the cusp/cleft region, in order to look at the dynamics of a specific event, as opposed to other data analyses which have used large data sets to acquire good statistics, but which can thereby obscure dynamics of the actual events. Particle data were taken by the electron spectrometer ESP 1 and the ion spectrometer PISP 1/2. They looked at the spectral range 0.01 to 40 keV. The UV imager recorded 1 sec exposures of the auroral distribution once per minute. The data shows instantaneous observations of emissions, and does so for a narrow path swept by the satellite. Data indicate that the entire region is not a homogeneous region, but rather a very dynamic object. Conclusions include that the emissions observed are located at the footprint of the cleft region. The cusp region is located poleward of the region with continuous emission. The emission is observed to remain at a constant magnetic latitude during the period with IMF data, though B z swung 8nT during a 30 minute period

Distinct ion population in the polar cusp: possible signature of transient reconnection

International Nuclear Information System (INIS)

Escoubet, C.P.; Smith, M.F.; Bosqued, J.M.

1992-01-01

Observations of ion energy dispersion are a common feature of the polar cusp. Normally these dispersions show a continuous decrease in energy. However, they occasionally show step-like features in the dispersion. On 15 October 1981 Dynamics Explorer 2 (DE2) crossed the polar cusp at 1015 MLT and observed three distinct ion populations as the spacecraft moved poleward. These three populations had peak-flux energy around 2.7 keV, 850 eV and 360 eV. The first step coincided with a rotation of the flow; the flow being directed westward on the equatorward edge, poleward in the center and eastward on the poleward edge. The second and third steps showed a flow directed principally poleward. Furthermore, the magnetic and electric perturbations in the first step are well fitted by an elongated FTE footprint model. These results suggest that three consecutive Flux Transfer Events (FTEs) have injected solar wind plasma into the ionosphere forming the polar cusp. The small latitudinal size of these FTE footprints (∼ 40 km) and their short recurrence rate (3 and 6 min) would be consistent with an intermittent reconnection taking place at the subsolar point on a short time scale

Steam-deformed Judkins-left guiding catheter with use of the GuideLiner catheter to deliver stents for anomalous right coronary artery

Directory of Open Access Journals (Sweden)

Toshiki Kuno

2015-10-01

Full Text Available Objective: Percutaneous coronary intervention for anomalous right coronary artery (RCA originating from the left coronary cusp is challenging because of our current inability to coaxially engage the guiding catheter. Methods: We report a case of an 88-year-old woman with non-ST segment elevation myocardial infarction, with an anomalous RCA origin. Using either the Judkins-Left catheter or Amplatz-Left catheter was difficult because of RCA ostium tortuosity. Thus, we used steam to deform the Judkins-Left catheter, but back-up support was insufficient to deliver the stent. Results: We used GuideLiner®, a novel pediatric catheter with rapid exchange/monorail systems, to enhance back-up support. Conclusions: We were able to successfully stent with both the deformed Judkins-Left guiding catheter and GuideLiner® for an anomalous RCA origin.

Scattering Study of a Modified Cusp Potential in Conformable Fractional Formalism

Energy Technology Data Exchange (ETDEWEB)

Chung, Won Sang [Gyeongsang National University, Jinju (Korea, Republic of); Zarrinkamar, Saber [Islamic Azad University, Garmsar (Iran, Islamic Republic of); Zare, Soroush [Islamic Azad University North Tehran Branch, Tehran (Iran, Islamic Republic of); Hassanabadi, Hassan [Shahrood University of Technology, Shahrood (Iran, Islamic Republic of)

2017-02-15

The fractional Schr¨odinger equation is considered with a cusp interaction. Exact analytical solutions are obtained and thereby the scattering states as well as transmission and reflection coefficients are determined.

The use of transcatheter aortic valve replacement vs surgical aortic valve replacement for the treatment of aortic stenosis

Directory of Open Access Journals (Sweden)

Jensen HA

2015-08-01

Full Text Available Hanna A Jensen, Lillian L Tsai, Vinod H Thourani Division of Cardiothoracic Surgery, Joseph B Whitehead Department of Surgery, Structural Heart and Valve Center, Emory University School of Medicine, Atlanta, GA, USA Abstract: Severe aortic stenosis (AS is associated with considerable morbidity and mortality and is increasing in prevalence as the global population increases. Since AS primarily affects the elderly, many of these patients have comorbidities that make them poor candidates for the gold standard treatment for AS, surgical aortic valve replacement. Transcatheter aortic valve replacement has emerged as a novel technology for the management of AS in higher risk patients over the past decade. Randomized trials have established the safety and efficacy of transcatheter aortic valve replacement, and the medical community has rallied to identify the patients who are most suitable for this transformative treatment. This review focuses on outlining the key procedural differences, describing the unique challenges of both operations, and finally assessing and comparing outcomes both on a general level and in challenging patient subgroups. Keywords: aortic valve replacement, transcatheter aortic valve replacement, surgical aortic valve replacement 

Altered aortic shape in bicuspid aortic valve relatives influences blood flow patterns.

Science.gov (United States)

Schnell, Susanne; Smith, Danielle A; Barker, Alex J; Entezari, Pegah; Honarmand, Amir R; Carr, Maria L; Malaisrie, S Chris; McCarthy, Patrick M; Collins, Jeremy; Carr, James C; Markl, Michael

2016-11-01

Bicuspid aortic valve (BAV) is known to exhibit familial inheritance and is associated with aortopathy and altered aortic haemodynamics. However, it remains unclear whether BAV-related aortopathy can be inherited independently of valve morphology. Four-dimensional flow magnetic resonance imaging for the in vivo assessment of thoracic aortic 3D blood flow was performed in 24 BAV relatives with trileaflet aortic valves (age = 40 ± 14 years) and 15 healthy controls (age = 37 ± 10 years). Data analysis included aortic dimensions, shape (round/gothic/cubic), and 3D blood flow characteristics (semi-quantitative vortex/helix grading and peak velocities). Cubic and gothic aortic shapes were markedly more prevalent in BAV relatives compared with controls (38 vs. 7%). Ascending aorta (AAo) vortex flow in BAV relatives was significantly increased compared with controls (grading = 1.5 ± 1.0 vs. 0.6 ± 0.9, P = 0.015). Aortic haemodynamics were influenced by aortic shape: peak velocities were reduced for gothic aortas vs. round aortas (P = 0.003); vortex flow was increased for cubic aortas in the AAo (P gothic aortas in the AAo and descending aorta (P = 0.003, P = 0.029). Logistic regression demonstrated significant associations of shape with severity of vortex flow in AAo (P < 0.001) and aortic arch (P = 0.016) in BAV relatives. BAV relatives expressed altered aortic shape and increased vortex flow despite the absence of valvular disease or aortic dilatation. These data suggest a heritable component of BAV-related aortopathy affecting aortic shape and aberrant blood flow, independent of valve morphology. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Cusp and W peak analysis in electron capture to the continuum of bare H and He projectiles from hydrocarbon and fluorocarbon gases

Energy Technology Data Exchange (ETDEWEB)

Joyce, J.M.; Bissinger, G.

1987-04-01

The ECC cusp and W peak shapes for continuum electron capture by approx. = MeV/u H/sup +/ and He/sup 2 +/ from hydrocarbon and fluorocarbon gas molecules are analyzed with the general parametric expression of Meckbach, Nemirovsky and Garibotti (i) to look for trends in the coefficients of these parameters, (ii) as a way of generating computed cusp shapes to reduce statistical fluctuations in cusp difference spectra, and (iii) to provide information on the deconvoluted d/sup 2/sigma/d..nu.. dtheta values for cusp and W peaks in the hydrocarbon gases.

Mandibular Facial Talon Cusp: A Rare Case Report | Prabhu ...

African Journals Online (AJOL)

Talon cusp (TC) is a relatively uncommon developmental anomaly characterized by cusp‑like projections from the cemento‑enamel junction to a variable distance toward the incisal edge of an anterior tooth. It usually presents on palatal/lingual surface of the anterior teeth. Studies have revealed that it consists of enamel, ...

Left ventricular mechanical adaptation to chronic aortic regurgitation in intact dogs

International Nuclear Information System (INIS)

Florenzano, F.; Glantz, S.A.

1987-01-01

Increased and end-diastolic wall stress has been hypothesized to stimulate left ventricular (LV) hypertrophy following volume overload. The authors instrumented intact-chest dogs with radiopaque markers in both ventricles and created volume overload by puncturing one aortic valve cusp. An x-ray system with biplane fluoroscopic and cineradiographic capabilities was used. End-diastolic stress increased immediately, then fell over 3 mo as the heart hypertrophied. End-systolic stress did not change significantly. Chamber contractility, quantified as E/sub max/, the end-systolic pressure-volume line slope, increased. E/sub max/ normalized by multiplying by LV mass increased following the lesion before but not after β-blockade with propranolol and did not change significantly over time, suggesting that chamber contractility changed because of increased mass and sympathetic tone rather than changed intrinsic muscle function. LV mass did not initially correlate with lesion size, but steady-state mass did. Over the range of lesions the authors produced, increased end-diastolic wall stress appears to stimulate hypertrophy at a fixed rate, which stops when end-diastolic wall stress has been reduced to an acceptable level

Molar cusp deformation evaluated by micro-CT and enamel crack formation to compare incremental and bulk-filling techniques.

Science.gov (United States)

Oliveira, Laís Rani Sales; Braga, Stella Sueli Lourenço; Bicalho, Aline Arêdes; Ribeiro, Maria Tereza Hordones; Price, Richard Bengt; Soares, Carlos José

2018-07-01

To describe a method of measuring the molar cusp deformation using micro-computed tomography (micro-CT), the propagation of enamel cracks using transillumination, and the effects of hygroscopic expansion after incremental and bulk-filling resin composite restorations. Twenty human molars received standardized Class II mesio-occlusal-distal cavity preparations. They were restored with either a bulk-fill resin composite, X-tra fil (XTRA), or a conventional resin composite, Filtek Z100 (Z100). The resin composites were tested for post-gel shrinkage using a strain gauge method. Cusp deformation (CD) was evaluated using the images obtained using a micro-CT protocol and using a strain-gauge method. Enamel cracks were detected using transillumination. The post-gel shrinkage of Z100 was higher than XTRA (P cracks than XTRA (P = 0.012). Micro-CT was an effective method for evaluating the cusp deformation. Transillumination was effective for detecting enamel cracks. There were fewer negative effects of polymerization shrinkage in bulk-fill resin restorations using XTRA than for the conventional incremental filling technique using conventional composite resin Z100. Shrinkage and cusp deformation are directly related to the formation of enamel cracks. Cusp deformation and crack propagation may increase the risk of tooth fracture. Copyright © 2018 Elsevier Ltd. All rights reserved.

Long-Term Risk for Aortic Complications After Aortic Valve Replacement in Patients With Bicuspid Aortic Valve Versus Marfan Syndrome.

Science.gov (United States)

Itagaki, Shinobu; Chikwe, Joanna P; Chiang, Yuting P; Egorova, Natalia N; Adams, David H

2015-06-09

Bicuspid aortic valves are associated with valve dysfunction, ascending aortic aneurysm and dissection. Management of the ascending aorta at the time of aortic valve replacement (AVR) in these patients is controversial and has been extrapolated from experience with Marfan syndrome, despite the absence of comparative long-term outcome data. This study sought to assess whether the natural history of thoracic aortopathy after AVR in patients with bicuspid aortic valve disease is substantially different from that seen in patients with Marfan syndrome. In this retrospective comparison, outcomes of 13,205 adults (2,079 with bicuspid aortic valves, 73 with Marfan syndrome, and 11,053 control patients with acquired aortic valve disease) who underwent primary AVR without replacement of the ascending aorta in New York State between 1995 and 2010 were compared. The median follow-up time was 6.6 years. The long-term incidence of thoracic aortic dissection was significantly higher in patients with Marfan syndrome (5.5 ± 2.7%) compared with those with bicuspid valves (0.55 ± 0.21%) and control group patients (0.41 ± 0.08%, p Marfan syndrome (10.8 ± 4.4%) compared with those with bicuspid valves (4.8 ± 0.8%) and control group patients (1.4 ± 0.2%) (p Marfan syndrome were significantly more likely to undergo thoracic aortic surgery in late follow-up (10.4 ± 4.3%) compared with those with bicuspid valves (2.5 ± 0.6%) and control group patients (0.50 ± 0.09%) (p Marfan syndrome compared with those with bicuspid aortic valves confirm that operative management of patients with bicuspid aortic valves should not be extrapolated from Marfan syndrome and support discrete treatment algorithms for these different clinical entities. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Signatures of the high-altitude polar cusp and dayside auroral regions as seen by the Viking electric field experiment

International Nuclear Information System (INIS)

Marklund, G.T.; Blomberg, L.G.; Faelthammar, C.G.; Erlandson, R.E.; Potemra, T.A.

1990-01-01

Electric field and satellite potential observations along 42 Viking orbits in the high-altitude (2R E ) polar cusp and dayside auroral region have been examined. Within the cusp the plasma density usually reaches a maximum, and it is typically very homogeneous, in contrast to the irregular and lower density in the cleft and dayside auroral regions. The maxima in the plasma density are sometimes anticorrelated with the magnetic field strength, indicating a diamagnetic effect. The entire cusp and dayside auroral regions are characterized by irregular and burstlike electric fields, comprising field reversals on various scales (up to 3 min or 500 km), the larger scales, however, being rare in the cusp. Another common feature in these regions is the high correlation between mutually orthogonal components of the electric and magnetic fields, both for large-scale variations across spatial structures and for wave and pulsations in the ULF frequency range. The electric field signatures in the cusp (in the 1100-1300 MLT sector) are, however, characteristically different from the cleft and oval field signatures in that the electric field is usually less intense and less structured and not correlated with the substorm activity level

Source of the dayside cusp aurora.

Science.gov (United States)

Mende, S B; Frey, H U; Angelopoulos, V

2016-08-01

Monochromatic all-sky imagers at South Pole and other Antarctic stations of the Automatic Geophysical Observatory chain recorded the aurora in the region where the Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites crossed the dayside magnetopause. In several cases the magnetic field lines threading the satellites when mapped to the atmosphere were inside the imagers' field of view. From the THEMIS magnetic field and the plasma density measurements, we were able to locate the position of the magnetopause crossings and map it to the ionosphere using the Tsyganenko-96 field model. Field line mapping is reasonably accurate on the dayside subsolar region where the field is strong, almost dipolar even though compressed. From these coordinated observations, we were able to prove that the dayside cusp aurora of high 630 nm brightness is on open field lines, and it is therefore direct precipitation from the magnetosheath. The cusp aurora contained significant highly structured N 2 + 427.8 nm emission. The THEMIS measurements of the magnetosheath particle energy and density taken just outside the magnetopause compared to the intensity of the structured N 2 + 427.8 nm emissions showed that the precipitating magnetosheath particles had to be accelerated. The most likely electron acceleration mechanism is by dispersive Alfvén waves propagating along the field line. Wave-accelerated suprathermal electrons were seen by FAST and DMSP. The 427.8 nm wavelength channel also shows the presence of a lower latitude hard-electron precipitation zone originating inside the magnetosphere.

IMF control of cusp proton emission intensity and dayside convection: implications for component and anti-parallel reconnection

Directory of Open Access Journals (Sweden)

M. Lockwood

2003-04-01

Full Text Available We study a brightening of the Lyman-a emission in the cusp which occurred in response to a short-lived south-ward turning of the interplanetary magnetic field (IMF during a period of strongly enhanced solar wind plasma concentration. The cusp proton emission is detected using the SI-12 channel of the FUV imager on the IMAGE spacecraft. Analysis of the IMF observations recorded by the ACE and Wind spacecraft reveals that the assumption of a constant propagation lag from the upstream spacecraft to the Earth is not adequate for these high time-resolution studies. The variations of the southward IMF component observed by ACE and Wind allow for the calculation of the ACE-to-Earth lag as a function of time. Application of the derived propagation delays reveals that the intensity of the cusp emission varied systematically with the IMF clock angle, the relationship being particularly striking when the intensity is normalised to allow for the variation in the upstream solar wind proton concentration. The latitude of the cusp migrated equatorward while the lagged IMF pointed southward, confirming the lag calculation and indicating ongoing magnetopause reconnection. Dayside convection, as monitored by the SuperDARN network of radars, responded rapidly to the IMF changes but lagged behind the cusp proton emission response: this is shown to be as predicted by the model of flow excitation by Cowley and Lockwood (1992. We use the numerical cusp ion precipitation model of Lockwood and Davis (1996, along with modelled Lyman-a emission efficiency and the SI-12 instrument response, to investigate the effect of the sheath field clock angle on the acceleration of ions on crossing the dayside magnetopause. This modelling reveals that the emission commences on each reconnected field line 2–2.5 min after it is opened and peaks 3–5 min after it is opened. We discuss how comparison of the Lyman-a intensities with oxygen emissions observed simultaneously by the SI-13

IMF By-Related Cusp Currents Observed from the Ørsted Satellite and from Ground

DEFF Research Database (Denmark)

Stauning, P.; Primdahl, Fritz; Watermann, J.

2001-01-01

Orsted is the first satellite to conduct high-precision magnetometer observations from low-altitude noonmidnight orbits passing through the polar cusp regions. Field-aligned currents (FAC) derived from Orsted magnetic field measurements have been combined with ionospheric current patterns inferred...... statistical analysis defines for the noon region the variations in FAC latitude with IMF B-Z. Comparisons with the statistical cusp location indicate that the more equatorward region of IMF B-gamma-while the more B related FAC is located on field lines closing at the dayside poleward FAC are on "open" field...

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.

The impact on bone tissues of immediate implant-supported mandibular overdentures with cusped and cuspless teeth

OpenAIRE

Khalid A. Arafa

2016-01-01

Objectives: To examine the effects on bone tissues of immediate implant-supported mandibular overdentures with cusped or cuspless teeth. Methods: A randomized controlled trial was conducted at the Dental Clinic, Faculty of Dentistry, Al-Azhar University, Assiut Branch, Egypt, over a 12-month period from September 2013 to September 2014. Twenty patients were treated with immediate implant-supported overdentures: one group received overdentures with cusped teeth, and the other group receive...

Confinement of a non cylindrical z discharge by a cusp geometry

International Nuclear Information System (INIS)

Watteau, J.H.

1968-03-01

The plasma of a non-cylindrical z discharge is accumulated in the centre of a cusp geometry and then captured and confined by the rising cusp magnetic field. The cusp geometry is produced by two identical coaxial coils the currents of which are equal but in opposite directions. Stability and confinement properties of this zero minimum B geometry are recalled; in particular it is shown (the coils cross section being supposed punctual) that the magnetic well depth of the configuration without plasma is maximum for an optimum coils distance. Two modes of confinement are observed experimentally : - a collisional mode for which the plasma confinement is limited to 10 μsec (temperature 5 eV, density 7 x 10 16 cm -3 ) as a result of the gradual interpenetration of the plasma and of the magnetic field. - a collisionless mode (temperature 40 eV) where the radial leak thickness is of the order of the ion cyclotron radius. Plasma accumulation occurs even without confinement and is due to the non-cylindrical shape of the discharge chamber. The two-dimensional snow-plough model gives good account of the discharge dynamics. A comparison is made with plasma focus experiments: in particular experimental conditions (deuterium, pressure 1 torr,energy 3 kJ, current 100 kA) a 10 7 neutron yield is detected which appears to be connected with the unstable behavior of the discharge. (authors) [fr

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

Science.gov (United States)

Laporte, Chervin F. P.; Peñarrubia, Jorge

2015-04-01

We study the evolution of the dark matter (DM) halo profiles of dwarf galaxies driven by the accretion of DM substructures through controlled N-body experiments. Our initial conditions assume that early supernova feedback erases the primordial DM cusps of haloes with z = 0 masses of 109 - 1010 M⊙. The orbits and masses of the infalling substructures are borrowed from the Aquarius cosmological 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 ≈ 0. Cusp regrowth is driven by the accretion of DM substructures that are dense enough to reach the central regions of the main halo before being tidally disrupted. The infall of substructures on the mean of the reported mass-concentration relation and a mass ratio above 1:6 systematically leads to cusp regrowth. Substructures with 1:6-1:8, and 1:8-1:30 only reform DM cusps if their densities are 1σ and 2σ above the mean, respectively. The merging time-scales of these dense, low-mass substructures is relatively long (5 - 11 Gyr), which may pose a time-scale problem for the longevity of DM cores in dwarfs galaxies and possibly explain the existence of dense dwarfs-like Draco. These results suggest that within cold dark matter a non-negligible level of scatter in the mass profiles of galactic haloes acted on by feedback is to be expected given the stochastic mass accretion histories of low-mass haloes and the diverse star formation histories observed in the Local Group dwarfs.

Aortic intramural hematoma : assessment of clinical and radiological features in comparison to acute aortic dissection

International Nuclear Information System (INIS)

Yoon, Kwon Ha; Hwang, Jae Cheol; Lee, Jin Seong; Kang, Duk Hyun; Song, Jae Kwan; Song, Koun Sik; Lim, Tae Hwan

1996-01-01

To compare the clinical and radiological features of aortic intramural hematoma(IMH) to those of acute aortic dissection(AD). We analyzed the clinical and radiological features of 12 patients with aortic IMH and 43 patients with acute AD. In aortic IMH, the diagnoses were made by means of both CT and transesophageal echocardiography(TEE) and included two surgically proven cases. In acute AD, the diagnoses were made by means of CT and TEE and included 21 surgically proven cases. We compared patients ages, etiologies, the extent of the disease, the presence or absence of aortic branch involvement, complications, and outcomes. Aortic IMH tended to develop in older patients (67.8±7.9 vs. 50.4±13.4, P .05). In aortic IMH, there was no involvement of aortic branches, whereas in acute AD, 14(33%) patients showed involvement of one or more aortic branches. Complications of aortic IMH included pericardial effusion (n=2) and pleural effusion (n=4);in acute AD, pericardial effusion (n=7), pleural effusion (n=4), aortic insufficiency (n=8), cerebral infarction (n=3), renal infarction (n=4) and spinal infarction (n=1) were seen. There was one (8%) death due to aortic IMH and ten (23%) deaths due to acute AD (p<.01). Aortic IMH is characterized by its occurrence in older patients with hypertension, a less frequent incidence of complications, and a more favorable outcome than acute AD

The impact on bone tissues of immediate implant-supported mandibular overdentures with cusped and cuspless teeth

Directory of Open Access Journals (Sweden)

Khalid A. Arafa

2016-01-01

Full Text Available Objectives: To examine the effects on bone tissues of immediate implant-supported mandibular overdentures with cusped or cuspless teeth. Methods: A randomized controlled trial was conducted at the Dental Clinic, Faculty of Dentistry, Al-Azhar University, Assiut Branch, Egypt, over a 12-month period from September 2013 to September 2014. Twenty patients were treated with immediate implant-supported overdentures: one group received overdentures with cusped teeth, and the other group received overdentures with cuspless teeth. The rate of implant success was assessed clinically and radiographically at 3, 6, 9, and 12 months. The data were collected by a questionnaire, an observation checklist, and radiography. The data were then analyzed using computerized methods. Results: Overdentures with cusped teeth showed a significant improvement in the clinical criteria, including the absence of clinical implant mobility, pain, and bone resorption, while the clinical criteria for the absence of peri-implant radiolucency were insignificantly different between the 2 groups (p>0.05. There were no significant differences in the clinical evaluations for bone levels at the time of insertion or 3 months after insertions, while significant differences were found at 6, 9, and 12 months after insertion. Conclusion: Overdentures with cusped teeth supported by immediate implants were found superior regarding many clinical criteria than those cuspless counterparts.

The impact on bone tissues of immediate implant-supported mandibular overdentures with cusped and cuspless teeth.

Science.gov (United States)

Arafa, Khalid A

2016-01-01

To examine the effects on bone tissues of immediate implant-supported mandibular overdentures with cusped or cuspless teeth. A randomized controlled trial was conducted at the Dental Clinic, Faculty of Dentistry, Al-Azhar University, Assiut Branch, Egypt, over a 12-month period from September 2013 to September 2014. Twenty patients were treated with immediate implant-supported overdentures: one group received overdentures with cusped teeth, and the other group received overdentures with cuspless teeth. The rate of implant success was assessed clinically and radiographically at 3, 6, 9, and 12 months. The data were collected by a questionnaire, an observation checklist, and radiography. The data were then analyzed using computerized methods.  Overdentures with cusped teeth showed a significant improvement in the clinical criteria, including the absence of clinical implant mobility, pain, and bone resorption, while the clinical criteria for the absence of peri-implant radiolucency were insignificantly different between the 2 groups (p more than 0.05). There were no significant differences in the clinical evaluations for bone levels at the time of insertion or 3 months after insertions, while significant differences were found at 6, 9, and 12 months after insertion. Overdentures with cusped teeth supported by immediate implants were found superior regarding many clinical criteria than those cuspless counterparts.

Transcatheter aortic valve replacement

Science.gov (United States)

... gov/ency/article/007684.htm Transcatheter aortic valve replacement To use the sharing features on this page, please enable JavaScript. Transcatheter aortic valve replacement (TAVR) is surgery to replace the aortic valve. ...

Black Holes and Galactic Density Cusps I Radial Orbit Cusps and Bulges

CERN Document Server

Henriksen, Richard N; Macmillan, Joseph D

2011-01-01

Aims. In this paper we study density cusps made from radial orbits that may contain central black holes. The actual co-eval self-similar growth would not distinguish between the central object and the surroundings. Methods. To study the environment of an existing black hole we seek distribution functions that may contain a black hole and that retain at least a memory of self-similarity. We refer to the environment in brief as the 'bulge' or sometimes the 'halo'. This depends on whether the black hole is a true singularity dominating its halo or rather a core mass concentration that dominates a larger bulge. The hierarchy might extend to include galactic bulge and halo. Results.We find simple descriptions of simulated collisionless matter in the process of examining the presence of central masses. The Fridmann & Polyachenko distribution function describes co-eval growth of a bulge and black hole that might explain the observed mass correlation. Conclusions. We derive our results from first principles assum...

Left Ventricular Assist Device Implantation with Concomitant Aortic Valve and Ascending Aortic Replacement.

Science.gov (United States)

Huenges, Katharina; Panholzer, Bernd; Cremer, Jochen; Haneya, Assad

2018-01-01

Left ventricular assist device (LVAD) is nowadays a routine therapy for patients with advanced heart failure. We present the case of a 74-year-old male patient who was admitted to our center with terminal heart failure in dilated cardiomyopathy and ascending aortic aneurysm with aortic valve regurgitation. The LVAD implantation with simultaneous aortic valve and supracoronary ascending aortic replacement was successfully performed.

Descriptive Analysis of In Vitro Cutting of Swine Mitral Cusps: Comparison of High-Power Laser and Scalpel Blade Cutting Techniques.

Science.gov (United States)

Pinto, Nathali Cordeiro; Pomerantzeff, Pablo Maria Alberto; Deana, Alessandro; Zezell, Denise; Benetti, Carolina; Aiello, Vera Demarchi; Lopes, Luciana Almeida; Jatene, Fabio Biscegli; Chavantes, M Cristina

2017-02-01

The most common injury to the heart valve with rheumatic involvement is mitral stenosis, which is the reason for a big number of cardiac operations in Brazil. Commissurotomy is the traditional technique that is still widely used for this condition, although late postoperative restenosis is concerning. This study's purpose was to compare the histological findings of porcine cusp mitral valves treated in vitro with commissurotomy with a scalpel blade to those treated with high-power laser (HPL) cutting, using appropriate staining techniques. Five mitral valves from healthy swine were randomly divided into two groups: Cusp group (G1), cut with a scalpel blade (n = 5), and Cusp group (G2), cut with a laser (n = 5). G2 cusps were treated using a diode laser (λ = 980 nm, power = 9.0 W, time = 12 sec, irradiance = 5625 W/cm 2 , and energy = 108 J). In G1, no histological change was observed in tissue. A hyaline basophilic aspect was focally observed in G2, along with a dark red color on the edges and areas of lower birefringence, when stained with hematoxylin-eosin, Masson's trichrome, and Sirius red. Further, the mean distances from the cutting edge in cusps submitted to laser application and stained with Masson's trichrome and Sirius red were 416.7 and 778.6 μm, respectively, never overcoming 1 mm in length. Thermal changes were unique in the group submitted to HPL and not observed in the cusp group cut with a scalpel blade. The mean distance of the cusps' collagen injury from the cutting edge was less than 1 mm with laser treatment. Additional studies are needed to establish the histological evolution of the laser cutting and to answer whether laser cutting may avoid valvular restenosis better than blade cutting.

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

International Nuclear Information System (INIS)

Ishizaka, Nobukazu; Sohmiya, Koichi; Miyamura, Masatoshi; Umeda, Tatsuya; Tsuji, Motomu; Katsumata, Takahiro; Miyata, Tetsuro

2012-01-01

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)

Aortic root surgery in Marfan syndrome: Comparison of aortic valve-sparing reimplantation versus composite grafting.

Science.gov (United States)

Karck, Matthias; Kallenbach, Klaus; Hagl, Christian; Rhein, Christine; Leyh, Rainer; Haverich, Axel

2004-02-01

The objective of this study was to compare the results of aortic valve-sparing reimplantation and aortic root replacement with mechanical valve conduits in patients with Marfan syndrome undergoing operation for aortic root aneurysms. Patients and methods Between March 1979 and April 2002, 119 patients with clinical evidence of Marfan syndrome underwent composite graft replacement with mechanical valve conduits (n = 74) or aortic valve-sparing reimplantation according to David (n = 45). The underlying causes were aortic dissection type A (43 patients) and aneurysms (76 patients). Patients undergoing aortic valve reimplantation were younger compared with patients undergoing composite grafting (28 vs 35 years, P =.002) and had longer intraoperative aortic crossclamp times (125 vs 78 minutes, P valve reimplantation (P =.15). Mean follow-up was 30 months for patients undergoing aortic valve reimplantation and 114 months for patients undergoing composite grafting. Freedom from reoperation and death after 5 years postoperatively was 92% and 89% in patients undergoing composite grafting and 84% and 96% in patients undergoing aortic valve reimplantation (P =.31; P =.54), respectively. Thromboembolic complications or late postoperative bleeding occurred in 17 patients undergoing composite grafting, and an early postoperative event occurred in 1 patient undergoing aortic valve reimplantation. The results of aortic valve reimplantation and composite grafting of the aortic valve and ascending aorta with mechanical valve conduits are similar with regard to early and mid-term postoperative mortality and to the incidence of late reoperations in patients with Marfan syndrome. The low risk of thromboembolic or bleeding complications favors aortic valve reimplantation in these patients.

Transcatheter valve-in-valve implantation due to severe aortic regurgitation in a degenerated aortic homograft

DEFF Research Database (Denmark)

Olsen, Lene Kjaer; Engstrøm, Thomas; Søndergaard, Lars

2009-01-01

Transcatheter aortic valve implantation (TAVI) in severe aortic stenosis has proven to be a feasible and effective treatment modality for inoperable patients. Until now, neither aortic regurgitation nor degenerated bioprostheses has been an indication for TAVI. However, this article reports...... a successful valve-in-valve implantation of a CoreValve aortic valve prosthesis through the right subclavian artery in a case of severe aortic regurgitation within a degenerated aortic homograft. The case exemplifies the possibilities of expanding the indications for TAVI, as well as other vascular access...

CUSP9* treatment protocol for recurrent glioblastoma: aprepitant, artesunate, auranofin, captopril, celecoxib, disulfiram, itraconazole, ritonavir, sertraline augmenting continuous low dose temozolomide.

Science.gov (United States)

Kast, Richard E; Karpel-Massler, Georg; Halatsch, Marc-Eric

2014-09-30

CUSP9 treatment protocol for recurrent glioblastoma was published one year ago. We now present a slight modification, designated CUSP9*. CUSP9* drugs--aprepitant, artesunate, auranofin, captopril, celecoxib, disulfiram, itraconazole, sertraline, ritonavir, are all widely approved by regulatory authorities, marketed for non-cancer indications. Each drug inhibits one or more important growth-enhancing pathways used by glioblastoma. By blocking survival paths, the aim is to render temozolomide, the current standard cytotoxic drug used in primary glioblastoma treatment, more effective. Although esthetically unpleasing to use so many drugs at once, the closely similar drugs of the original CUSP9 used together have been well-tolerated when given on a compassionate-use basis in the cases that have come to our attention so far. We expect similarly good tolerability for CUSP9*. The combined action of this suite of drugs blocks signaling at, or the activity of, AKT phosphorylation, aldehyde dehydrogenase, angiotensin converting enzyme, carbonic anhydrase -2,- 9, -12, cyclooxygenase-1 and -2, cathepsin B, Hedgehog, interleukin-6, 5-lipoxygenase, matrix metalloproteinase -2 and -9, mammalian target of rapamycin, neurokinin-1, p-gp efflux pump, thioredoxin reductase, tissue factor, 20 kDa translationally controlled tumor protein, and vascular endothelial growth factor. We believe that given the current prognosis after a glioblastoma has recurred, a trial of CUSP9* is warranted.

Origin of energetic ions in the polar cusp inferred from ion composition measurements by the Viking satellite

Directory of Open Access Journals (Sweden)

G. Kremser

1995-06-01

Full Text Available The magnetospheric ion composition spectrometer MICS on the Swedish Viking satellite provided measurements of the ion composition in the energy range 10.1 keV/e\\leqE/Q\\leq326.0 keV/e. Data obtained during orbit 842 were used to investigate the ion distribution in the northern polar cusp and its vicinity. The satellite traversed the outer ring current, boundary region, cusp proper and plasma mantle during its poleward movement. H+ and He++ ions were encountered in all of these regions. He+ ions were present only in the ring current. The number of O+ and O++ ions was very small. Heavy high-charge state ions typical for the solar wind were observed for the first time, most of them in the poleward part of the boundary region and in the cusp proper. The H+ ions exhibited two periods with high intensities. One of them, called the BR/CP event, appeared at energies up to 50 keV. It started at the equatorward limit of the boundary region and continued into the cusp proper. Energy spectra indicate a ring current origin for the BR/CP event. Pitch angle distributions show downward streaming of H+ ions at its equatorward limit and upward streaming on the poleward side. This event is interpreted as the result of pitch angle scattering of ring current ions by fluctuations in the magnetopause current layer in combination with poleward convection. The other of the two periods with high H+ ion intensities, called the accelerated ion event, was superimposed on the BR/CP event. It was restricted to energies \\leq15 keV and occurred in the poleward part of the boundary region. This event is regarded as the high-energy tail of magnetosheath ions that were accelerated while penetrating into the magnetosphere. The cusp region thus contains ions of magnetospheric as well as of magnetosheath origin. The appearance of the ions depends, in addition to the ion source, on the magnetic field configuration and dynamic processes inside and close to the cusp.

IMF control of cusp proton emission intensity and dayside convection: implications for component and anti-parallel reconnection

Directory of Open Access Journals (Sweden)

M. Lockwood

Full Text Available We study a brightening of the Lyman-a emission in the cusp which occurred in response to a short-lived south-ward turning of the interplanetary magnetic field (IMF during a period of strongly enhanced solar wind plasma concentration. The cusp proton emission is detected using the SI-12 channel of the FUV imager on the IMAGE spacecraft. Analysis of the IMF observations recorded by the ACE and Wind spacecraft reveals that the assumption of a constant propagation lag from the upstream spacecraft to the Earth is not adequate for these high time-resolution studies. The variations of the southward IMF component observed by ACE and Wind allow for the calculation of the ACE-to-Earth lag as a function of time. Application of the derived propagation delays reveals that the intensity of the cusp emission varied systematically with the IMF clock angle, the relationship being particularly striking when the intensity is normalised to allow for the variation in the upstream solar wind proton concentration. The latitude of the cusp migrated equatorward while the lagged IMF pointed southward, confirming the lag calculation and indicating ongoing magnetopause reconnection. Dayside convection, as monitored by the SuperDARN network of radars, responded rapidly to the IMF changes but lagged behind the cusp proton emission response: this is shown to be as predicted by the model of flow excitation by Cowley and Lockwood (1992. We use the numerical cusp ion precipitation model of Lockwood and Davis (1996, along with modelled Lyman-a emission efficiency and the SI-12 instrument response, to investigate the effect of the sheath field clock angle on the acceleration of ions on crossing the dayside magnetopause. This modelling reveals that the emission commences on each reconnected field line 2–2.5 min after it is opened and peaks 3–5 min after it is opened. We discuss how comparison of the Lyman-