Thin-shell wormholes with a generalized Chaplygin gas in Einstein-Born-Infeld theory

We construct spherically symmetric thin-shell wormholes supported by a generalized Chaplygin gas in Born-Infeld electrodynamics coupled to Einstein gravity, and we analyze their stability under radial perturbations. For different values of the Born-Infeld parameter and the charge, we compare the results with those obtained in a previous work for Maxwell electrodynamics. The stability region in the parameter space reduces and then disappears as the value of the Born-Infeld parameter is modified in the sense of a larger departure from Maxwell theory.Comment: 9 pages, 6 figures; v2: improved versio

Aneurismas Toracoabdominais Rotos [ruptured Thoracoabdominal Aneurysms]

Objective: To evaluate the pre-, intra- and postoperative data of ruptured thoracoabdominal aneurysms operated at Hospital de Clínicas da Universidade Estadual de Campinas. Methods: A retrospective study of five patients submitted to repair of ruptured thoracoabdominal aneurysm at Hospital de Clínicas da Universidade Estadual de Campinas from September 2000 to April 2004. All patients presented a ruptured type IV thoracoabdominal aneurysm, and four of them were hemodynamically stable. Three patients were operated by the simple supraceliac aortic clamping and saline solution infusion at 4°C in the renal arteries; one patient died during the surgery before the aneurysm was opened; and one patient was operated by perfusion of oxygenated blood in the visceral arteries. Results: Of the five patients operated, two died (40%). One of them presented hemodynamic instability and died during the surgery; the other patient died on the 26 th postoperative day due to multiple organ failure. All three surviving patients progressed well, with no sequelae. Among patients who were taken to the operating room hemodynamically stable, the mortality rate was 25%. Conclusions: Patients with ruptured type IV thoracoabdominal aneurysm, hemodynamically stable, achieved satisfactory surgical results, similar to infrarenal ruptured aneurysms. Copyright © 2006 by Sociedade Brasileira de Angiologia e de Cirurgia Vascular.513741Bradbury, A.W., Bulstrode, N.W., Gilling-Smith, G., Stansby, G., Mansfield, A.O., Wolfe, J.H., Repair of ruptured thoracoabdominal aortic aneurysm is worthwhile in selected cases (1999) Eur J Vasc Endovasc Surg, 17, pp. 160-165Lewis, M.E., Ranasinghe, A.M., Revell, M.P., Bonser, R.S., Surgical repair of ruptured thoracic and thoracoabdominal aortic aneurysms (2002) Br J Surg, 89, pp. 442-445Cowan Jr., J.A., Dimick, J.B., Wainess, R.M., Henke, P.K., Stanley, J.C., Upchurch Jr., G.R., Ruptured thoracoabdominal aortic aneurysm treatment in the United States: 1988 to 1998 (2003) J Vasc Surg, 38, pp. 319-322LeMaire, S.A., Rice, D.C., Schmittling, Z.C., Coselli, J.S., Emergency surgery for thoracoabdominal aortic aneurysms with acute presentation (2002) J Vasc Surg, 35, pp. 1171-1178Rocha, E.F., Luccas, G.C., Baldini Neto, L., Aneurisma tóracoabdominal inflamatório (2005) J Vasc Br, 4, pp. 301-306Rocha, E.F., Guillaumon, A.T., Antunes, N., Vieira, R.W., Aneurisma toracoabdominal roto: Modificação do circuito de perfusão visceral (2004) Rev Bras Cir Cardiovasc, 19, pp. 413-416Mastroroberto, P., Chello, M., Emergency thoracoabdominal aortic repair: Clinical outcome (1999) J Thorac Cardiovasc Surg, 118, pp. 477-481Cota, A.M., Omer, A.A., Jaipersad, A.S., Wilson, N.V., Elective versus ruptured abdominal aortic aneurysm repair: A 1-year cost-effectiveness analysis (2005) Ann Vasc Surg, 19, pp. 858-861Girardi, L.N., Krieger, K.H., Altorki, N.K., Mack, C.A., Lee, L.Y., Isom, O.W., Ruptured descending and thoracoabdominal aortic aneurysms (2002) Ann Thorac Surg, 74, pp. 1066-1070Schepens, M.A., Defauw, J.J., Hamerlijnck, R.P., De Geest, R., Vermeulen, F.E., Surgical treatment of thoracoabdominal aortic aneurysms by simple crossclamping. Risk factors and late results (1994) J Thorac Cardiovasc Surg, 107, pp. 134-142Cambria, R.P., Davison, J.K., Zannetti, S., L'Italien, G., Atamian, S., Thoracoabdominal aneurysm repair: Perspectives over a decade with the clamp-and-sew technique (1997) Ann Surg, 226, pp. 294-303Anacleto, A., Anacleto, J.C., Aneurismas da aorta torácica e toracoabdominal (2002) Cirurgia Vascular: Cirurgia Endovascular, Angiologia, pp. 439-459. , Brito CJ. Rio de Janeiro: RevinterSantos, V.P., Ignácio, M.R., Da Silveira, D.R., Caffaro, R.A., Aneurisma toracoabdominal roto: Relato de um caso com o uso de anel rígido sulcado de Delrin intraluminal na anastomose proximal (2004) J Vasc Br, 3, pp. 383-38

Stability of Non-asymptotically flat thin-shell wormholes in generalized dilaton-axion gravity

We construct a new type of thin-shell wormhole for non-asymptotically flat charged black holes in generalized dilaton-axion gravity inspired by low-energy string theory using cut-and-paste technique. We have shown that this thin shell wormhole is stable. The most striking feature of our model is that the total amount of exotic matter needed to support the wormhole can be reduced as desired with the suitable choice of the value of a parameter. Various other aspects of thin-shell wormhole are also analyzed.Comment: 15 pages and 11 figures. Minor revisions have been done. Accepted in Int.J.Theor.Phy

Thin-shell wormholes from black holes with dilaton and monopole fields

We provide a new type of thin-shell wormhole from the black holes with dilaton and monopole fields. The dilaton and monopole that built the black holes may supply fuel to construct the wormholes. Several characteristics of this thin-shell wormhole have been discussed. Finally, we discuss the stability of the thin-shell wormholes with a "phantom-like" equation of state for the exotic matter at the throat.Comment: 6 pages and 3 figures, some typos are corrected and accepted in Int.J.Theor.Phy