Permanent Junctional Reciprocating Tachycardia: an Incessant Tachycardia in Children

A taquicardia juncional recíproca permanente é uma forma de taquicardia supraventricular de reentrada pouco comum, embora constitua a causa mais frequente de taquicardia incessante em crianças. O seu carácter permanente causa disfunção ventricular esquerda e miocardiopatia dilatada e é de difícil controlo terapêutico. Objectivo: Rever as características clínicas mais significativas desta arritmia, a sua evolução e as opções terapêuticas actuais. Métodos: estudo retrospectivo, analisando a forma de apresentação e evolução, com particular relevo para a resposta à terapêutica farmacológica e alternativas terapêuticas. Doentes: Grupo de 5 doentes com o diagnóstico de taquicardia juncional recíproca permanente. Resultados: As crianças estudadas tinham idades compreendidas entre os 14 dias e os 12 anos. Três encontravam-se assintomáticas. O primeiro ecocardiograma demonstrou dilatação do ventrículo esquerdo e diminuição da fracção de encurtamento em uma das crianças. A terapêutica farmacológica foi inicialmente eficaz em todos os casos. Ao longo do seguimento (0,2-4,5 anos) a arritmia tornou-se refractária em um dos casos, pelo que se procedeu a ablação da via anómala por radiofrequência. Conclusões: A taquicardia juncional recíproca permanente tem diversas formas de apresentação. A terapêutica farmacológica é recomendada, mas tem carácter transitório. A ablação por radiofrequência é o tratamento definitivo, estando condicionada pela idade dos doentes

Spacetime Fermions in Light-cone Gauge Superstring Field Theory and Dimensional Regularization

We consider the dimensional regularization of the light-cone gauge type II superstring field theories in the NSR formalism. In the previous work, we have calculated the tree-level amplitudes with external lines in the (NS,NS) sector using the regularization and shown that the desired results are obtained without introducing contact term interactions. In this work, we study the tree-level amplitudes with external lines in the Ramond sector. In order to deal with them, we propose a worldsheet theory to be used instead of that for the naive dimensional regularization. With the worldsheet theory, we regularize and define the tree-level amplitudes by analytic continuation. We show that the results coincide with those of the first quantized formulation.Comment: 28 pages, 5 figures; v2: more details of our manipulations in subsection 3.2 added, figures and references added; v3: clarifications adde

Extra dimensions in CERN LHC via mini-black holes: effective Kerr-Newman brane-world effects

We solve Einstein equations on the brane to derive the exact form of the braneworld-corrected perturbations in Kerr-Newman singularities, using Randall-Sundrum and Arkani-Hamed-Dimopoulos-Dvali (ADD) models. It is a consequence of such models the possibility that Kerr-Newman mini-black holes can be produced in LHC. We use this approach to derive a normalized correction for the Schwarzschild Myers-Perry radius of a static $(4+n)$-dimensional mini-black hole, using more realistic approaches arising from Kerr-Newman mini-black hole analysis. Besides, we prove that there are four Kerr-Newman black hole horizons in braneworld scenario we use, although only the outer horizon is relevant in the physical measurable processes. Parton cross sections in LHC and Hawking temperature are also investigated as functions of Planck mass (in the LHC range 1-10 TeV), mini-black hole mass and the number of large extra dimensions in braneworld large extra-dimensional scenarios. In this case a more realistic brane effect-corrected formalism can achieve more precisely the effective extra-dimensional Planck mass and the number of large extra dimensions -- in Arkani-Hamed-Dimopoulos-Dvali model -- or the size of the warped extra dimension -- in Randall-Sundrum formalism.Comment: 11 pages, 23 figures, citations update

Discrete approaches to quantum gravity in four dimensions

The construction of a consistent theory of quantum gravity is a problem in theoretical physics that has so far defied all attempts at resolution. One ansatz to try to obtain a non-trivial quantum theory proceeds via a discretization of space-time and the Einstein action. I review here three major areas of research: gauge-theoretic approaches, both in a path-integral and a Hamiltonian formulation, quantum Regge calculus, and the method of dynamical triangulations, confining attention to work that is strictly four-dimensional, strictly discrete, and strictly quantum in nature.Comment: 33 pages, invited contribution to Living Reviews in Relativity; the author welcomes any comments and suggestion

Could the variation in quasar luminosity, due to extra dimension 3-brane in RS model, be measurable?

We propose an alternative theoretical approach showing how the existence of an extra dimension in RS model can estimate the correction in the Schwarzschild radius of black holes, and consequently its measurability in terms of the variation of quasar luminosity, which can be caused by a imprint of an extra dimension endowing the geometry of a brane-world scenario in an AdS_5 bulk. This paper is intended to investigate the variation of luminosity due to accretion of gas in black holes (BHs) in the center of quasars, besides also investigating the variation of luminosity in supermassive BHs by brane-world effects, using RS model.Comment: Revtex4, 7 Pages, 6 Figures, v2 has minor change

Expression and Function of Androgen Receptor Coactivator p44/Mep50/WDR77 in Ovarian Cancer

Hormones, including estrogen and progesterone, and their receptors play an important role in the development and progression of ovarian carcinoma. Androgen, its receptor and coactivators have also been implicated in these processes. p44/Mep50/WDR77 was identified as a subunit of the methylosome complex and lately characterized as a steroid receptor coactivator that enhances androgen receptor as well as estrogen receptor-mediated transcriptional activity in a ligand-dependent manner. We previously described distinct expression and function of p44 in prostate, testis, and breast cancers. In this report, we examined the expression and function of p44 in ovarian cancer. In contrast to findings in prostate and testicular cancer and similar to breast cancer, p44 shows strong cytoplasmic localization in morphologically normal ovarian surface and fallopian tube epithelia, while nuclear p44 is observed in invasive ovarian carcinoma. We observed that p44 can serve as a coactivator of both androgen receptor (AR) and estrogen receptor (ER) in ovarian cells. Further, overexpression of nuclear-localized p44 stimulates proliferation and invasion in ovarian cancer cells in the presence of estrogen or androgen. These findings strongly suggest that p44 plays a role in mediating the effects of hormones during ovarian tumorigenesis

Comparative genetic analysis: the utility of mouse genetic systems for studying human monogenic disease

One of the long-term goals of mutagenesis programs in the mouse has been to generate mutant lines to facilitate the functional study of every mammalian gene. With a combination of complementary genetic approaches and advances in technology, this aim is slowly becoming a reality. One of the most important features of this strategy is the ability to identify and compare a number of mutations in the same gene, an allelic series. With the advent of gene-driven screening of mutant archives, the search for a specific series of interest is now a practical option. This review focuses on the analysis of multiple mutations from chemical mutagenesis projects in a wide variety of genes and the valuable functional information that has been obtained from these studies. Although gene knockouts and transgenics will continue to be an important resource to ascertain gene function, with a significant proportion of human diseases caused by point mutations, identifying an allelic series is becoming an equally efficient route to generating clinically relevant and functionally important mouse models

Microbial community structure elucidates performance of Glyceria maxima plant microbial fuel cell

The plant microbial fuel cell (PMFC) is a technology in which living plant roots provide electron donor, via rhizodeposition, to a mixed microbial community to generate electricity in a microbial fuel cell. Analysis and localisation of the microbial community is necessary for gaining insight into the competition for electron donor in a PMFC. This paper characterises the anode–rhizosphere bacterial community of a Glyceria maxima (reed mannagrass) PMFC. Electrochemically active bacteria (EAB) were located on the root surfaces, but they were more abundant colonising the graphite granular electrode. Anaerobic cellulolytic bacteria dominated the area where most of the EAB were found, indicating that the current was probably generated via the hydrolysis of cellulose. Due to the presence of oxygen and nitrate, short-chain fatty acid-utilising denitrifiers were the major competitors for the electron donor. Acetate-utilising methanogens played a minor role in the competition for electron donor, probably due to the availability of graphite granules as electron acceptors