Classical Solutions in a Lorentz-violating Maxwell-Chern-Simons Electrodynamics

We take as starting point the planar model arising from the dimensional reduction of the Maxwell Electrodynamics with the (Lorentz-violating) Carroll-Field-Jackiw term. We then write and study the extended Maxwell equations and the corresponding wave equations for the potentials. The solution to these equations show some interesting deviations from the usual MCS Electrodynamics, with background-dependent correction terms. In the case of a time-like background, the correction terms dominate over the MCS sector in the region far from the origin, and establish the behaviour of a massless Electrodynamics (in the electric sector). In the space-like case, the solutions indicate the clear manifestation of spatial anisotropy, which is consistent with the existence of a privileged direction is space.Comment: latex, 8 page

Supersymmetric Extension of the Lorentz and CPT-Violating Maxwell-Chern-Simons Model

Focusing on gauge degrees of freedom specified by a 1+3 dimensions model hosting a Maxwell term plus a Lorentz and CPT non-invariant Chern-Simons-like contribution, we obtain a minimal extension of such a system to a supersymmetric environment. We comment on resulting peculiar self-couplings for the gauge sector, as well as on background contribution for gaugino masses. Furthermore, a non-polynomial generalization is presented.Comment: revtex4, 4 pages, no figure

Histopathological Analysis Of Gangliosides Use In Peripheral Nerve Regeneration After Axonotmesis In Rats

Purpose: To analyze the action of gangliosides in peripheral nerve regeneration in the sciatic nerve of the rat. Methods: The sample was composed of 96 male Wistar rats. The animals were anaesthetized and, after identification of the anaesthesic plane, an incision was made in the posterior region of the thigh, followed by skin and muscle divulsion. The right sciatic nerve was isolated and compressed for 2 minutes. Continuous suture of the skin was performed. The animals were randomly divided into two groups: the experimental group (EG), which received subcutaneous injection of gangliosides, and the control group (CG), which received saline solution (0.9%) to mimic the effects of drug administration. Results: No differences were observed between the experimental and control groups evaluated on the eighth day of observation. At 15 and 30 days the EG showed an decrease in Schwann cell activity and an apparent improvement in fibre organization; at 60 days, there was a slight presence of Schwann cells in the endoneural space and the fibres were organized, indicating nerve regeneration. At 15 and 30 days, the level of cell reaction in the CG had diminished, but there were many cells with cytoplasm in activity and in mitosis; at 60 days, hyperplastic Schwann cells and mitotic activity were again observed, as well as nerve regeneration, but to a lesser extent than in the EG. Conclusion: The administration of exogenous gangliosides seems to improve nerve regeneration.234364371Vasconcelos, B.C., Gay Escoda, C., Vasconcellos, R.J., Neves, R.F., Conduction velocity of the rabbit facial nerve: A noninvasive functional evaluation (2003) Pesqui Odontol Bras, 17, pp. 126-131De Medinacelli, L., Freed, W.J., Wyatt, R.J., An index of the functional condition of rat sciatic nerve based on measurements made from walking tracks (1982) Exp Neur, 77, pp. 6634-6643Nachemson, A.K., Lundborg, G., Myrhage, R., Rank, F., Nerve regeneration and pharmacological suppression of the scar reaction at the suture site (1985) Scand J Plast Reconstr Surg, 19, pp. 255-260Danielsen, N., Varon, S., Characterization of neurotrophic activity in the silicone chamber model for nerve regeneration (1995) J Reconstr Microsurg, 11, pp. 231-235Catan, F.G., Pastorello, A., Siliprandi, R., Savastano, M., Molinari, G., Brain cortex gangliosides and Na+, K+)-ATPase system of the stria vascularis in the guinea pig (1981) Acta Otolaryngol, 92, pp. 433-437Cunha, M.T.R., Silva, A.R., Fenelon, S.B., Comparision of nerve integration after segmentar resection versus epineural burying in crushed rat sciatic nerves (1997) Acta Cir Bras, 4, pp. 221-225Chen, Z.Y., Chai, Y.F., Cao, L., Lu, C.L., He, C., Glial cell line-derived neurotrophic factor enhances axonal regeneration following sciatic nerve transection in adult rats (2001) Brain Res, 2, pp. 272-276Abreu, A.A.N., Wei, T.H., Zumiotti, A.V., Avaliação dos gangliosídeos na regeneração nervosa em ratos. (2002) Rev Bras Ortop, 37, pp. 39-44Neto, J.C., Vasconcelos, B.C., Sobral, A.P., da Silva Jr, V.A., Nogueira, R.V., Clinical and histopathologic study of the use of gangliosides for nerve regeneration in rats after axonotmesis (2007) J Oral Maxillofac Surg, 65, pp. 870-874de Ruiter, G.C., Spinner, R.J., Alaid, A.O., Koch, A.J., Wang, H., Malessy, M.J., Currier, B.L., Windebank, A.J., Two-dimensional digital video ankle motion analysis for assessment of function in the rat sciatic nerve model (2007) J Peripher Nerv Syst, 12, pp. 216-222Schmalbruch, H., Fiber composition of the sciatic nerve (1986) Anat Rec, 215 (1), pp. 71-81Apley, A.G., Teaching techniques and training methods in orthopaedics (1966) Proc R Soc Med, 59 (2), p. 117Kline, D.G., Kim, D., Midha, R., Harsh, C., Tiel, R., Management and results of sciatic nerve injuries: A 24-year experience (1998) J Neurosurg, 89, pp. 13-23Gomes AC, Vasconcelos BC, de Oliveira e Silva ED, da Silva LC. Lingual nerve damage after mandibular third molar surgery: a randomized clinical trial. J Oral Maxillofac Surg. 2005;63:1443-6Horch, H.W., Krüttgen, A., Portbury, S.D., Katz, L.C., Destabilization of cortical dendrites and spines by BDNF (1999) Neuron, 23 (2), pp. 353-364Tos, P., Ronchi, G., Nicolino, S., Audisio, C., Raimondo, S., Fornaro, M., Battiston, B., Geuna, S., Employment of the mouse median nerve model for the experimental assessment of peripheral nerve regeneration (2008) J Neurosci Methods, 169 (1), pp. 119-127Graff-Radford, S.B., Evans, R.W., Lingual nerve injury (2003) Headache, 43, pp. 975-983Montovani, J.C., Prado, R.G., Bacchi, C.E., Experimental surgery of the facial nerve: Evaluation of the intraperitoneal use of exogenous gangliosides (1995) Rev Laryngol Otol Rhinol, 116, pp. 163-167Langone, F., Silva, C.F., Exogenous ganglioside stimulation of axonal regeneration after new transsection and intubation repair (1990) Braz J Med Biol, 23, pp. 823-826Lainetti, R.D., Silva, C.F., Local addition of monosialoganglioside GM1 stimulates peripheral axon regeneration in vivo (1993) Braz J Med Biol Res, 26, pp. 841-845Sobeski, J.K., Kerns, J.M., Safanda, J.F., Shott, S., Gonzalez, M.H., Functional and structural effects of GM-1 ganglioside treatment on peripheral nerve grafting in the rat (2001) Microsurgery, 21, pp. 108-115Amico-Roxas, M., Caruso, A., Trombadore, S., Scifo, R., Scapagnini, U., Gangliosides antinociceptive effects in rodents (1984) Arch Int Pharmacodyn Ther, 272 (1), pp. 103-117(1978) United Nations Educational, Scientific and Culture Organization, , http://portal.unesco.org/en/ev.php-URL_ID=29008&URL_DO=DO_TOPIC&URL_SECTION=201.html, Universal Declaration of Animal Rights, Bruxelles. Available from UR

Stem cell transplantation for fanconi anemia: 20 years of progressive decrease in the dose of cyclophosphamide without irradiation

La fesomia actual és de finals del segle XVIII.Primer pla, contrapicat, d'un senzill edifici d'habitatges entre mitgeres. Consta de planta baixa, quatre plantes pis i terrat, amb un volum reculat respecte el pla de façana. S'organitza en tres eixos verticals. Combina balcons amb finestretes

Reduction of blood nitric oxide levels is associated with clinical improvement of the chronic pelvic pain related to endometriosis

The objective of this prospective study was to determine the plasma levels of nitric oxide (NO) in women with chronic pelvic pain secondary to endometriosis (n=24) and abdominal myofascial pain syndrome (n=16). NO levels were measured in plasma collected before and 1 month after treatment. Pretreatment NO levels (μM) were lower in healthy volunteers (47.0±12.7) than in women with myofascial pain (64.2±5.0, P=0.01) or endometriosis (99.5±12.9, P<0.0001). After treatment, plasma NO levels were reduced only in the endometriosis group (99.5±12.9 vs 61.6±5.9, P=0.002). A correlation between reduction of pain intensity and reduction of NO level was observed in the endometriosis group [correlation = 0.67 (95%CI = 0.35 to 0.85), P<0.0001]. Reduction of NO levels was associated with an increase of pain threshold in this group [correlation = -0.53 (-0.78 to -0.14), P<0.0001]. NO levels appeared elevated in women with chronic pelvic pain diagnosed as secondary to endometriosis, and were directly associated with reduction in pain intensity and increase in pain threshold after treatment. Further studies are needed to investigate the role of NO in the pathophysiology of pain in women with endometriosis and its eventual association with central sensitization.484363369CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQSem informaçã

Kondo lattice model with a direct exchange interaction between localized moments

We study the Kondo lattice model with a direct antiferromagnetic exchange interaction between localized moments. Ferromagnetically long-range ordered state coexisting with the Kondo screening shows a continuous quantum phase transition to the Kondo singlet state. We obtain the value of the critical point where the magnetizations of the localized moments and the conduction electrons vanish. The magnetization curves yield a universal critical exponent independent of the filling factors and the strength of the interaction between localized moments. It is shown that the direct exchange interaction between localized moments introduces another phase transition from an antiferromagnetic ordering to a ferromagnetic ordering for small Kondo exchange interaction. We also explain the local minimum of the Kondo temperature in recent experiments.Comment: 6 pages, 5 figures, final versio

Ultrarelativistic electron-hole pairing in graphene bilayer

We consider ground state of electron-hole graphene bilayer composed of two independently doped graphene layers when a condensate of spatially separated electron-hole pairs is formed. In the weak coupling regime the pairing affects only conduction band of electron-doped layer and valence band of hole-doped layer, thus the ground state is similar to ordinary BCS condensate. At strong coupling, an ultrarelativistic character of electron dynamics reveals and the bands which are remote from Fermi surfaces (valence band of electron-doped layer and conduction band of hole-doped layer) are also affected by the pairing. The analysis of instability of unpaired state shows that s-wave pairing with band-diagonal condensate structure, described by two gaps, is preferable. A relative phase of the gaps is fixed, however at weak coupling this fixation diminishes allowing gapped and soliton-like excitations. The coupled self-consistent gap equations for these two gaps are solved at zero temperature in the constant-gap approximation and in the approximation of separable potential. It is shown that, if characteristic width of the pairing region is of the order of magnitude of chemical potential, then the value of the gap in the spectrum is not much different from the BCS estimation. However, if the pairing region is wider, then the gap value can be much larger and depends exponentially on its energy width.Comment: 13 pages with 8 figures; accepted to Eur. Phys. J.

Faraday rotation in graphene

We study magneto--optical properties of monolayer graphene by means of quantum field theory methods in the framework of the Dirac model. We reveal a good agreement between the Dirac model and a recent experiment on giant Faraday rotation in cyclotron resonance. We also predict other regimes when the effects are well pronounced. The general dependence of the Faraday rotation and absorption on various parameters of samples is revealed both for suspended and epitaxial graphene.Comment: 10 pp; v2: typos corrected and references added, v3, v4: small changes and more reference

Energy Contents of Some Well-Known Solutions in Teleparallel Gravity

In the context of teleparallel equivalent to General Relativity, we study energy and its relevant quantities for some well-known black hole solutions. For this purpose, we use the Hamiltonian approach which gives reasonable and interesting results. We find that our results of energy exactly coincide with several prescriptions in General Relativity. This supports the claim that different energy-momentum prescriptions can give identical results for a given spacetime. We also evaluate energy-momentum flux of these solutions.Comment: 16 pages, accepted for publication in Astrophys. Space Sc