326 research outputs found
ON THE SOLUTIONS OF ELECTRICAL IMPEDANCE EQUATION: A PSEUDOANALYTIC APPROACH FOR SEPARABLE-VARIABLES CONDUCTIVITY FUNCTION
Using a quaternionic reformulation of the electrical impedance equation, we consider a two-dimensional separable-variables conductivity function and, posing two different techniques, we obtain a special class of Vekua equation, whose general solution can be approach by virtue of Taylor series in formal powers, for which is possible to introduce an explicit Bers generating sequence
Searching for a light Fermiophobic Higgs Boson at the Tevatron
We propose new production mechanisms for light fermiophobic Higgs bosons
() with suppressed couplings to vector bosons () at the Fermilab
Tevatron. These mechanisms (e.g. ) are complementary to the
conventional process , which suffers from a strong suppression of
in realistic models with a . The new mechanisms extend the
coverage at the Tevatron Run II to the larger region, and offer the
possibility of observing new event topologies with up to 4 photons.Comment: 15 pages, including 5 eps-figure
Directional atherectomy for treatment of restenosis within coronary stents: clinical, angiographic and histologic results
Abstract
OBJECTIVES: The safety and long-term results of directional coronary atherectomy in stented coronary arteries were determined. In addition, tissue studies were performed to characterize the development of restenosis.
METHODS: Directional coronary atherectomy was performed in restenosed stents in nine patients (10 procedures) 82 to 1,179 days after stenting. The tissue was assessed for histologic features of restenosis, smooth muscle cell phenotype, markers of cell proliferation and cell density. A control (no stenting) group consisted of 13 patients treated with directional coronary atherectomy for restenosis 14 to 597 days after coronary angioplasty, directional coronary atherectomy or laser intervention.
RESULTS: Directional coronary atherectomy procedures within the stent were technically successful with results similar to those of the initial stenting procedure (2.31 +/- 0.38 vs. 2.44 +/- 0.35 mm). Of five patients with angiographic follow-up, three had restenosis requiring reintervention (surgery in two and repeat atherectomy followed by laser angioplasty in one). Intimal hyperplasia was identified in 80% of specimens after stenting and in 77% after coronary angioplasty or atherectomy. In three patients with stenting, 70% to 76% of the intimal cells showed morphologic features of a contractile phenotype by electron microscopy 47 to 185 days after coronary intervention. Evidence of ongoing proliferation (proliferating cell nuclear antigen antibody studies) was absent in all specimens studied. Although wide individual variability was present in the maximal cell density of the intimal hyperplasia, there was a trend toward a reduction in cell density over time.
CONCLUSIONS: Although atherectomy is feasible for the treatment of restenosis in stented coronary arteries and initial results are excellent, recurrence of restenosis is common. Intimal hyperplasia is a nonspecific response to injury regardless of the device used and accounts for about 80% of cases of restenosis. Smooth muscle cell proliferation and phenotypic modulation toward a contractile phenotype are early events and largely completed by the time of clinical presentation of restenosis. Restenotic lesions may be predominantly cellular, matrix or a combination at a particular time after a coronary procedure
Alteraçþes psiquiåtricas e qualidade de vida em pacientes com homocistinúria clåssica
Caracterizar o quadro psiquiĂĄtrico e a qualidade de vida (QoL) em uma coorte de pacientes com HomocistinĂşria ClĂĄssica (HCU). MĂŠtodos: estudo transversal, atravĂŠs da aplicação das escalas BPRS, Escala de Ansiedade de Beck, Escala de DepressĂŁo de Hamilton e Escala de DepressĂŁo de Beck (BDI) em 8 pacientes nĂŁo responsivos Ă piridoxina e estudo retrospectivo avaliando qualidade de vida por meio da aplicação do questionĂĄrio WHOQOL-Brief em 11 pacientes com HCU. Resultados: 5 pacientes avaliados apresentaram sintomas de depressĂŁo mĂnimos, 2 pacientes apresentaram sintomas leves, e 1 paciente sintomas moderados a graves. Para ansiedade, 5 pacientes apresentaram sintomas mĂnimos, 1 paciente apresentou sintomas leves e 2 pacientes apresentaram sintomas moderados. Cinco pacientes apresentaram algum sintoma relacionado Ă esquizofrenia. Em relação a QoL, todos pacientes apresentaram diagnĂłstico tardio e apenas 2 tinham QI>70 (Teste WASI). Os pacientes responsivos Ă piridoxina foram comparados com os nĂŁo responsivos Ă piridoxina mostrando melhor pontuação nos aspectos psicolĂłgicos e sociais no primeiro grupo. Os 2 pacientes com tratamento foram comparados com os 9 sem tratamento mostrando um melhor escore no aspecto psicolĂłgico no primeiro grupo. ConclusĂŁo: este ĂŠ o primeiro estudo que descreve QoL em pacientes HCU, mostrando uma diferença no aspecto psicolĂłgico e social, conforme o tipo de tratamentoFil: Donis, Karina C. Universidade Federal do Rio Grande do Sul (Brasil).Fil: Kalil, Marco A.B. Universidade Federal do Rio Grande do Sul (Brasil).Fil: Perrone, Solanger G. Universidade Federal do Rio Grande do Sul (Brasil).Fil: Teruya, KĂĄtia. Universidade Federal do Rio Grande do Sul (Brasil).Fil: Vanz, Ana P. Universidade Federal do Rio Grande do Sul (Brasil).Fil: Vairo, Filippo P. Universidade Federal do Rio Grande do Sul (Brasil).Fil: Schwartz, Ida V.D. Universidade Federal do Rio Grande do Sul (Brasil)
Usefulness of the updated logistic clinical SYNTAX score after percutaneous coronary intervention in patients with prior coronary artery bypass graft surgery: Insights from the GLOBAL LEADERS trial
Objectives: We aimed to investigate the prognostic utility of the anatomical CABG SYNTAX and logistic clinical SYNTAX scores for mortality after percutaneous coronary intervention (PCI) in patients with prior coronary artery bypass grafts (CABG). Background: The anatomical SYNTAX score evaluated the anatomical complexity of coronary artery disease and helped predict the prognosis of patients undergoing PCI. The anatomical CABG SYNTAX score was derived from the anatomical SYNTAX score in patients with prior CABG, whilst the logistic clinical SYNTAX score was developed by incorporating clinical factors into the anatomical SYNTAX score. Methods: We calculated the anatomical CABG SYNTAX score and logistic clinical SYNTAX score in 205 patients in the GLOBAL LEADERS trial. The predictive abilities of these scores for 2-year all-cause mortality were evaluated. Results: Using the median scores as categorical thresholds between low and high score groups, the logistic clinical SYNTAX score was able to discriminate the risk of 2-year mortality, unlike the anatomical CABG SYNTAX score. The logistic clinical SYNTAX was significantly better at predicting 2-year mortality, compared to the anatomical CABG SYNTAX score, as evidenced by AUC values in receiver-operating characteristic curve analysis (0.806 vs. 0.582, p <.001) and integrated discrimination improvement (0.121, p <.001). Conclusions: The logistic clinical SYNTAX score was superior to the anatomical CABG SYNTAX score in predicting 2-year mortality
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV
The Lambda(b) differential production cross section and the cross section
ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum
pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7
TeV using data collected by the CMS experiment at the LHC. The measurements are
based on Lambda(b) decays reconstructed in the exclusive final state J/Psi
Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and
Lambda to proton pion, using a data sample corresponding to an integrated
luminosity of 1.9 inverse femtobarns. The product of the cross section times
the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls
faster than that of b mesons. The measured value of the cross section times the
branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06
+/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for
anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are
statistical and systematic, respectively.Comment: Submitted to Physics Letters
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