1,361 research outputs found

    A Bovine Pericardium Rigid Prosthesis For Left Ventricle Restoration: 12 Years Of Follow-up [prótese Rígida De Pericárdio Bovino Para Remodelamento Ventricular Esquerdo: 12 Anos De Seguimento]

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    Background: Myocardial infarction might result in dilated left ventricle and numerous techniques have been described to restore the original left ventricle shape and identify tools for late survival assessment. The aim of this study is to compare our experience with a modified Dor procedure using a rigid prosthesis to the septal anterior ventricular exclusion procedure (SAVE) for left ventricle restoration. The EuroScore index for prediction of late follow up survival was evaluated. Methods: We evaluated 80 patients who underwent left ventricle restoration between 1999 to 2007 and eight patients were excluded with incomplete data. A modified Dor procedure with rigid prosthesis (MD group) was performed on 53 patients and 19 underwent the septal anterior ventricular exclusion procedure (SAVE group). The patients were classified according their left ventricle shape as type I, II or III. Kaplan-Meier and Cox proportional hazard ratio regressions analysis were performed to assess survival after both techniques and expected surgical mortality using EuroScore index ranking after 12 years of follow up. Results: The operative mortality was comparable in both groups ranked by EuroScore index. The groups were comparable for all clinical data, except the MD group had more patients using intra-aortic balloon pumps before surgery, (5.7% vs. 0; P<0.01). Kaplan Meier analysis by left ventricle shape showed comparable survival for all patients, with slightly higher survival for type I. Kaplan Meier analysis of all death showed equivalent survival curves for both techniques after 12 years of follow up (71.5 ± 12.3 vs. 46.6 ±20.5 years; P=0.08). Kaplan Meier analysis of EuroScore index for all patients showed a difference between the three ranked categories, i.e., 0 to 10%, 11 to 49% and higher than 50% expected surgical mortality after 12 years of follow up (70.9 ± 16.2 vs. 67.5 ± 12.7 vs. 53.0 ± 15.5; P=0.003). Conclusion: The MD procedure showed consistent ejection fraction improvements after long term follow up. Survival was comparable for all ventricular types and for the MD and SAVE procedures. The EuroScore index is a useful index for late survival assessment of ventricular restoration techniques.262164172Cooley, D.A., Hallman, G.L., Henly, W.S., Left ventricular aneurysm due to myocardial infarctionexperience with 37 patients undergoing aneurysmectomy (1964) Arch Surg, 88, pp. 114-121Jatene, A.D., Left ventricular aneurysmectomy. Resection or reconstruction (1985) J Thorac Cardiovasc Surg, 89 (3), pp. 321-331Dor, V., Saab, M., Coste, P., Kornaszewska, M., Montiglio, F., Left ventricular aneurysm: A new surgical approach (1989) Thorac Cardiovasc Surg, 37 (1), pp. 11-19Dor, V., Sabatier, M., di Donato, M., Montiglio, F., Toso, A., Maioli, M., Efficacy of endoventricular patch plasty in large postinfarction akinetic scar and severe left ventricular dysfunction: Comparison with a series of large dyskinetic scars (1998) J Thorac Cardiovasc Surg, 116 (1), pp. 50-59Braile, D.M., Mustafa, R.M., Ardito, R.V., Zaiantchick, M., Coelho, W.M., (1991) Correction of the Left Ventricle Geometry with Semi Rigid Bovine Pericardial Prosthesis Rev Bras Cir Cardiovasc, 6 (2), pp. 109-115Isomura, T., Horii, T., Suma, H., Buckberg, G.D., Septal anterior ventricular exclusion operation (Pacopexy) for ischemic dilated cardiomyopathy: Treat form not disease (2006) Eur J Cardiothorac Surg, 29 (SUPPL. 1), pp. S245-S250. , RESTORE GroupJones, R.H., Velazquez, E.J., Michler, R.E., Sopko, G., Oh, J.K., O'Connor, C.M., Coronary bypass surgery with or without surgical ventricular reconstruction (2009) N Engl J Med, 360 (17), pp. 1705-1717di Donato, M., Castelvecchio, S., Kukulski, T., Bussadori, C., Giacomazzi, F., Frigiola, A., Surgical ventricular restoration: Left ventricular shape influence on cardiac function, clinical status, and survival (2009) Ann Thorac Surg, 87 (2), pp. 455-461Najafi, M., Sheikhvatan, M., Montazeri, A., Sheikhfathollahi, M., Predictors of quality of life among patients undergoing coronary artery bypass surgery (2008) Acta Cardiol, 63 (6), pp. 713-721Messaoudi, N., de Cocker, J., Stockman, B.A., Bossaert, L.L., Rodrigus, I.E., Is EuroSCORE useful in the prediction of extended intensive care unit stay after cardiac surgery? (2009) Eur J Cardiothorac Surg, 36 (1), pp. 35-39Santarpino, G., Onorati, F., Rubino, A.S., Abdalla, K., Caroleo, S., Santangelo, E., Preoperative intraaortic balloon pumping improves outcomes for high-risk patients in routine coronary artery bypass graft surgery (2009) Ann Thorac Surg, 87 (2), pp. 481-488Nashef, S.A., Roques, F., Michel, P., Gauducheau, E., Lemeshow, S., Salamon, R., European system for cardiac operative risk evaluation (EuroSCORE) (1999) Eur J Cardiothorac Surg, 16 (1), pp. 9-13Dor, V., Sabatier, M., di Donato, M., Maioli, M., Toso, A., Montiglio, F., Late hemodynamic results after left ventricular patch repair associated with coronary grafting in patients with postinfarction akinetic or dyskinetic aneurysm of the left ventricle (1995) J Thorac Cardiovasc Surg, 110 (5), pp. 1291-1299Athanasuleas, C.L., Buckberg, G.D., Stanley, A.W., Siler, W., Dor, V., Didonato, M., RESTORE Group. Surgical ventricular restoration: The RESTORE Group experience (2004) Heart Fail Rev, 9 (4), pp. 287-297Salati, M., di Biasi, P., Paje, A., Santoli, C., Left ventricular geometry after endoventriculoplasty (1993) Eur J Cardiothorac Surg, 7 (11), pp. 574-578Buckberg, G.D., Coghlan, H.C., Torrent-Guasp, F., The structure and function of the helical heart and its buttress wrapping. VI. Geometric Concepts of Heart Failure and Use For Structural Correction (2001) Semin Thorac Cardiovasc Surg, 13 (4), pp. 386-401di Donato, M., Sabatier, M., Dor, V., Gensini, G.F., Toso, A., Maioli, M., Effects of the Dor procedure on left ventricular dimension and shape and geometric correlates of mitral regurgitation one year after surgery (2001) J Thorac Cardiovasc Surg, 121 (1), pp. 91-96Suma, H., Horii, T., Isomura, T., Buckberg, G., A new concept of ventricular restoration for nonischemic dilated cardiomyopathy (2006) Eur J Cardiothorac Surg, 29 (SUPPL. 1), pp. S207-S212. , RESTORE GroupForm versus disease: Optimizing geometry during ventricular restoration (2006) Eur J Cardiothorac Surg, 29 (SUPPL. 1), pp. S238-S244. , RESTORE GroupKieser, T.M., The left ventricle: To reconstruct or not: Lessons from the STICH trial (2009) J Thorac Cardiovasc Surg, 138 (3), p. 784Suma, H., Isomura, T., Horii, T., Buckberg, G., Role of site selection for left ventriculoplasty to treat idiopathic dilated cardiomyopathy (2004) Heart Fail Rev, 9 (4), pp. 329-336. , RESTORE GroupDancini, J.L., Rodrigues, J.J., Santos, J.S., Pinto, R.F.A., Burgos, F.J.C., Conforti, C.A., Left ventricular aneurysmectomy: Late followup (1996) Rev Bras Cir Cardiovasc, 1 (11), pp. 23-29Almeida, R.M.S., Lima, J.D., Bastos, L.C., Carvalho, C.T., Loures, D.R., Endoventricular circular patch plasty with septal exclusion: Initial experience (2000) Rev Bras Cir Cardiovasc, 4 (15), pp. 302-307Campagnucci, V.P., Rivetti, L.A., Pinto e Silva, A.M.R., Gandra, S.M.A., Pereira, W.L., Aneurismectomia de ventrículo esquerdo com o coração batendo ininterruptamente: Resultados imediatos (2006) Rev Bras Cir Cardiovasc, 21 (1), pp. 55-61Herrera, C.B., Insalralde, A., Brandi, A.C., Santos, C.A., Herrera, D.D., Soares, M.J.F., Correção de aneurisma de ventrículo esquerdo em paciente chagásico empregando prótese de pericárdio bovino (2000) Rev Bras Cir Cardiovasc, 15 (1), pp. 72-74Sgarbi, C.J., Ardito, R.V., Santos, R.C., Bogdan, R.A.B., Arruda Jr., F.V., Silva, E.M., Correção cirúrgica do aneurisma de ventrículo esquerdo: Comparação entre as técnicas de sutura linear e reconstrução geométrica (2000) Rev Bras Cir Cardiovasc, 15 (4), pp. 293-301Versteegh, M.I., Lamb, H.J., Bax, J.J., Curiel, F.B., van der Wall, E.E., de Roos, A., MRI evaluation of left ventricular function in anterior LV aneurysms before and after surgical resection (2003) Eur J Cardiothorac Surg, 23 (4), pp. 609-613Use of cardiac magnetic resonance imaging in surgical ventricular restoration (2006) Eur J Cardiothorac Surg, 29 (SUPPL. 1), pp. S216-S224. , Buckberg GD;RESTORE GroupWalker, J.C., Guccione, J.M., Jiang, Y., Zhang, P., Wallace, A.W., Hsu, E.W., Helical myofiber orientation after myocardial infarction and left ventricular surgical restoration in sheep (2005) J Thorac Cardiovasc Surg, 129 (2), pp. 382-39

    Observing Long Colour Flux Tubes in SU(2) Lattice Gauge Theory

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    We present results of a high statistics study of the chromo field distribution between static quarks in SU(2) gauge theory on lattices of volumes 16^4, 32^4, and 48^3*64, with physical extent ranging from 1.3 fm up to 2.7 fm at beta=2.5, beta=2.635, and beta=2.74. We establish string formation over physical distances as large as 2 fm. The results are tested against Michael's sum rules. A detailed investigation of the transverse action and energy flux tube profiles is provided. As a by-product, we obtain the static lattice potential in unpreceded accuracy.Comment: 66 pages, 29 figures, uuencoded latex file with epsfigures (450 K), supplementary full colour figures are available via ftp, CERN-TH.7413/94 (extended version

    Wave packet revivals and the energy eigenvalue spectrum of the quantum pendulum

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    The rigid pendulum, both as a classical and as a quantum problem, is an interesting system as it has the exactly soluble harmonic oscillator and the rigid rotor systems as limiting cases in the low- and high-energy limits respectively. The energy variation of the classical periodicity (τ\tau) is also dramatic, having the special limiting case of τ\tau \to \infty at the 'top' of the classical motion (i.e. the separatrix.) We study the time-dependence of the quantum pendulum problem, focusing on the behavior of both the (approximate) classical periodicity and especially the quantum revival and superrevival times, as encoded in the energy eigenvalue spectrum of the system. We provide approximate expressions for the energy eigenvalues in both the small and large quantum number limits, up to 4th order in perturbation theory, comparing these to existing handbook expansions for the characteristic values of the related Mathieu equation, obtained by other methods. We then use these approximations to probe the classical periodicity, as well as to extract information on the quantum revival and superrevival times. We find that while both the classical and quantum periodicities increase monotonically as one approaches the 'top' in energy, from either above or below, the revival times decrease from their low- and high-energy values until very near the separatrix where they increase to a large, but finite value.Comment: 27 pages, 8 embedded .eps figures; to appear, Annals of Physic

    Palaeoproterozoic magnesite: lithological and isotopic evidence for playa/sabkha environments

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    Magnesite forms a series of 1- to 15-m-thick beds within the approximate to2.0 Ga (Palaeoproterozoic) Tulomozerskaya Formation, NW Fennoscandian Shield, Russia. Drillcore material together with natural exposures reveal that the 680-m-thick formation is composed of a stromatolite-dolomite-'red bed' sequence formed in a complex combination of shallow-marine and non-marine, evaporitic environments. Dolomite-collapse breccia, stromatolitic and micritic dolostones and sparry allochemical dolostones are the principal rocks hosting the magnesite beds. All dolomite lithologies are marked by delta C-13 values from +7.1 parts per thousand to +11.6 parts per thousand (V-PDB) and delta O-18 ranging from 17.4 parts per thousand to 26.3 parts per thousand (V-SMOW). Magnesite occurs in different forms: finely laminated micritic; stromatolitic magnesite; and structureless micritic, crystalline and coarsely crystalline magnesite. All varieties exhibit anomalously high delta C-13 values ranging from +9.0 parts per thousand to +11.6 parts per thousand and delta O-18 values of 20.0-25.7 parts per thousand. Laminated and structureless micritic magnesite forms as a secondary phase replacing dolomite during early diagenesis, and replaced dolomite before the major phase of burial. Crystalline and coarsely crystalline magnesite replacing micritic magnesite formed late in the diagenetic/metamorphic history. Magnesite apparently precipitated from sea water-derived brine, diluted by meteoric fluids. Magnesitization was accomplished under evaporitic conditions (sabkha to playa lake environment) proposed to be similar to the Coorong or Lake Walyungup coastal playa magnesite. Magnesite and host dolostones formed in evaporative and partly restricted environments; consequently, extremely high delta C-13 values reflect a combined contribution from both global and local carbon reservoirs. A C- 13-rich global carbon reservoir (delta C-13 at around +5 parts per thousand) is related to the perturbation of the carbon cycle at 2.0 Ga, whereas the local enhancement in C-13 (up to +12 parts per thousand) is associated with evaporative and restricted environments with high bioproductivity

    Jekyll and Hyde: men's constructions of feminism and feminists

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    Research and commentary on men's responses to feminism has demonstrated the range of ways in which men have mobilised both against and for feminist principles. This paper argues that further analyses of men's responses require a sophisticated theory of discourse acknowledging the fragmented and contradictory nature of representation. A corpus of men's talk on feminism and feminists was studied to identify the pervasive patterns in men's accounting and regularities in rhetorical organisation. Material from two samples of men was included: a sample of white middle-class 17-18 year old school students and a sample of 60 interviews with a more diverse sample of older men aged 20 to 64. Two interpretative repertoires of feminism and feminists were identified. These set up a 'Jekyll and Hyde' binary and positioned feminism along with feminists very differently as reasonable versus extreme and monstrous. Both repertoires tended to be deployed together and the paper explores the ideological and interactional consequences of typical deployments along with the identity work accomplished by the men as they positioned themselves in relation to these

    Residual cognitive deficits 50 years after lead poisoning during childhood

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    The long term neurobehavioural consequences of childhood lead poisoning are not known. In this study adult subjects with a documented history of lead poisoning before age 4 and matched controls were examined with an abbreviated battery of neuropsychological tests including measures of attention, reasoning, memory, motor speed, and current mood. The subjects exposed to lead were inferior to controls on almost all of the cognitive tasks. This pattern of widespread deficits resembles that found in children evaluated at the time of acute exposure to lead rather than the more circumscribed pattern typically seen in adults exposed to lead. Despite having completed as many years of schooling as controls, the subjects exposed to lead were lower in lifetime occupational status. Within the exposed group, performance on the neuropsychological battery and occupational status were related, consistent with the presumed impact of limitations in neuropsychological functioning on everyday life. The results suggest that many subjects exposed to lead suffered acute encephalopathy in childhood which resolved into a chronic subclinical encephalopathy with associated cognitive dysfunction still evident in adulthood. These findings lend support to efforts to limit exposure to lead in childhood

    The imposition of Cauchy data to the Teukolsky equation I: The nonrotating case

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    Gravitational perturbations about a Kerr black hole in the Newman-Penrose formalism are concisely described by the Teukolsky equation. New numerical methods for studying the evolution of such perturbations require not only the construction of appropriate initial data to describe the collision of two orbiting black holes, but also to know how such new data must be imposed into the Teukolsky equation. In this paper we show how Cauchy data can be incorporated explicitly into the Teukolsky equation for non-rotating black holes. The Teukolsky function % \Psi and its first time derivative tΨ\partial_t \Psi can be written in terms of only the 3-geometry and the extrinsic curvature in a gauge invariant way. Taking a Laplace transform of the Teukolsky equation incorporates initial data as a source term. We show that for astrophysical data the straightforward Green function method leads to divergent integrals that can be regularized like for the case of a source generated by a particle coming from infinity.Comment: 9 pages, REVTEX. Misprints corrected in formulas (2.4)-(2.7). Final version to appear in PR

    Time-symmetric initial data for binary black holes in numerical relativity

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    We look for physically realistic initial data in numerical relativity which are in agreement with post-Newtonian approximations. We propose a particular solution of the time-symmetric constraint equation, appropriate to two momentarily static black holes, in the form of a conformal decomposition of the spatial metric. This solution is isometric to the post-Newtonian metric up to the 2PN order. It represents a non-linear deformation of the solution of Brill and Lindquist, i.e. an asymptotically flat region is connected to two asymptotically flat (in a certain weak sense) sheets, that are the images of the two singularities through appropriate inversion transformations. The total ADM mass M as well as the individual masses m_1 and m_2 (when they exist) are computed by surface integrals performed at infinity. Using second order perturbation theory on the Brill-Lindquist background, we prove that the binary's interacting mass-energy M-m_1-m_2 is well-defined at the 2PN order and in agreement with the known post-Newtonian result.Comment: 27 pages, to appear in Phys. Rev.
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