404 research outputs found

    On the existence of bounded solutions for a nonlinear elliptic system

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    This work deals with the system (−Δ)mu=a(x)vp(-\Delta)^m u= a(x) v^p, (−Δ)mv=b(x)uq(-\Delta)^m v=b(x) u^q with Dirichlet boundary condition in a domain \Omega\subset\RR^n, where Ω\Omega is a ball if n≥3n\ge 3 or a smooth perturbation of a ball when n=2n=2. We prove that, under appropriate conditions on the parameters (a,b,p,q,m,na,b,p,q,m,n), any non-negative solution (u,v)(u,v) of the system is bounded by a constant independent of (u,v)(u,v). Moreover, we prove that the conditions are sharp in the sense that, up to some border case, the relation on the parameters are also necessary. The case m=1m=1 was considered by Souplet in \cite{PS}. Our paper generalize to m≥1m\ge 1 the results of that paper

    Radial Solutions for Hamiltonian Elliptic Systems with Weights

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    We prove the existence of infinitely many radial solutions for elliptic systems in Rn with power weights. A key tool for the proof will be a weighted imbedding theorem for fractional-order Sobolev spaces, that could be of independent interest.Comment: 13 page

    Solutions of the divergence and Korn inequalities on domains with an external cusp

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    This paper deals with solutions of the divergence for domains with external cusps. It is known that the classic results in standard Sobolev spaces, which are basic in the variational analysis of the Stokes equations, are not valid for this class of domains. For some bounded domains Ω⊂Rn\Omega\subset{\mathbb R}^n presenting power type cusps of integer dimension m≤n−2m\le n-2, we prove the existence of solutions of the equation divu=f{div}{\bf u}=f in weighted Sobolev spaces, where the weights are powers of the distance to the cusp. The results obtained are optimal in the sense that the powers cannot be improved. As an application, we prove existence and uniqueness of solutions of the Stokes equations in appropriate spaces for cuspidal domains. Also, we obtain weighted Korn type inequalities for this class of domains

    Correlation between voxel based morphometry and manual volumetry in magnetic resonance images of the human brain

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    This is a comparative study between manual volumetry (MV) and voxel based morphometry (VBM) as methods of evaluating the volume of brain structures in magnetic resonance images. The volumes of the hippocampus and the amygdala of 16 panic disorder patients and 16 healthy controls measured through MV were correlated with the volumes of gray matter estimated by optimized modulated VBM. The chosen structures are composed almost exclusively of gray matter. Using a 4 mm Gaussian filter, statistically significant clusters were found bilaterally in the hippocampus and in the right amygdala in the statistical parametric map correlating with the respective manual volume. With the conventional 12 mm filter,a significant correlation was found only for the right hippocampus. Therefore,narrowfilters increase the sensitivity of the correlation procedure, especially when small brain structures are analyzed. The two techniques seem to consistently measure structural volume.Trata-se de estudo comparativo entre a volumetria manual(VM) e a morfometria baseada no vóxel (MBV), como métodos de avaliação do volume de estruturas cerebrais. Os volumes do hipocampo e da amídala de 16 pacientes de pânico e 16 controles sadios medidos através da VM foram correlacionados com os volumes de matéria cinzenta estimados pela MBV.As estruturas escolhidas são constituídas quase exclusivamente de matéria cinzenta. Utilizando um filtro Gaussiano de 4 mm, encontram-se, bilateralmente, aglomerados significativos de correlação nas duas estruturas no mapa estatístico paramétrico, correspondendo ao respectivo volume manual. Com o filtro convencional de 12 mm, apenas uma correlação significativa foi encontrada no hipocampo direito. Portanto, filtros estreitos aumentam a sensibilidade do procedimento de correlação,especialmente quando estruturas pequenas são analisadas. Ambas as técnicas parecem medir consistentemente o volume estrutural.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)(FAEPA) Hospital das Clínicas da FMRPUSP - Fundação de Apoio ao Ensino, Pesquisa e Asssistênci

    Overactive bladder-18 years - Part I

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    Overactive bladder syndrome is one of the lower urinary tract dysfunctions with the highest number of scientific publications over the past two decades. This shows the growing interest in better understanding this syndrome, which gathers symptoms of urinary urgency and increased daytime and nighttime voiding frequency, with or without urinary incontinence and results in a negative impact on the quality of life of approximately one out of six individuals - including both genders and almost all age groups. The possibility of establishing the diagnosis just from clinical data made patients' access to specialized care easier. Physiotherapy resources have been incorporated into the urological daily practice. A number of more selective antimuscarinic drugs with consequent lower adverse event rates were released. Recently, a new class of oral drugs, beta-adrenergic agonists has become part of the armamentarium for Overactive Bladder. Botulinum toxin injections in the bladder and sacral neuromodulation are routine modalities of treatment for refractory cases. During the 1st Latin-American Consultation on Overactive Bladder, a comprehensive review of the literature related to the evolution of the concept, epidemiology, diagnosis, and management was conducted. This text corresponds to the first part of the review Overactive Bladder 18-years.Univ Fed Sao Paulo, EPM, Rua Dr Oscar Monteiro Barros 617-141, BR-05641010 Sao Paulo, SP, BrazilUniv Sao Paulo, Dept Urol, BR-05508 Sao Paulo, SP, BrazilFac Med ABC, Dept Urol, Sao Paulo, SP, BrazilUniv Los Andes, Dept Urol, Bogota, ColombiaEscuela Med, Dept Urol, Mexico City, DF, MexicoHosp Clin Jose San Martin, Catedra Urol, Buenos Aires, DF, ArgentinaMae de Deus Ctr Hosp, Dept Urol, Porto Alegre, RS, BrazilUniv Fed Ciencias Saude Porto Alegre, Porto Alegre, RS, BrazilAC Camargo Hosp, Dept Urol, Sao Paulo, BrazilHosp Clin Fuerza Area Chile, Santiago, ChileInst Mexicano Seguro Social, Mexico City, DF, MexicoHosp Souza Aguiar, Dept Urol, Rio De Janeiro, RJ, BrazilComplejo Med Policial Churruca Visca, Serv Urol, Buenos Aires, DF, ArgentinaCtr Policlin Valencia Vina, Valencia, VenezuelaHosp Pablo Tobon Uribe, Medellin, ColombiaClin Indisa, Serv Urol, Providencia, ChileCtr Reabilitacao & Readaptacao Dr Henriqe Santill, Goiania, Go, BrazilHosp Univ Caracas, Serv Urol, Caracas, VenezuelaUniv Fed Ceara, Div Urol, Fortaleza, Ceara, BrazilUniv Fed Sao Paulo, EPM, Rua Dr Oscar Monteiro Barros 617-141, BR-05641010 Sao Paulo, SP, BrazilWeb of Scienc

    Overactive bladder-18 years - Part II

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    Traditionally, the treatment of overactive bladder syndrome has been based on the use of oral medications with the purpose of reestablishing the detrusor stability. The recent better understanding of the urothelial physiology fostered conceptual changes, and the oral anticholinergics - pillars of the overactive bladder pharmacotherapy - started to be not only recognized for their properties of inhibiting the detrusor contractile activity, but also their action on the bladder afference, and therefore, on the reduction of the symptoms that constitute the syndrome. Beta-adrenergic agonists, which were recently added to the list of drugs for the treatment of overactive bladder, still wait for a definitive positioning - as either a second-line therapy or an adjuvant to oral anticholinergics. Conservative treatment failure, whether due to unsatisfactory results or the presence of adverse side effects, define it as refractory overactive bladder. In this context, the intravesical injection of botulinum toxin type A emerged as an effective option for the existing gap between the primary measures and more complex procedures such as bladder augmentation. Sacral neuromodulation, described three decades ago, had its indication reinforced in this overactive bladder era. Likewise, the electric stimulation of the tibial nerve is now a minimally invasive alternative to treat those with refractory overactive bladder. The results of the systematic literature review on the oral pharmacological treatment and the treatment of refractory overactive bladder gave rise to this second part of the review article Overactive Bladder - 18 years, prepared during the 1st Latin-American Consultation on Overactive Bladder.Univ Fed Sao Paulo, EPM, Sao Paulo, SP, BrazilUniv Sao Paulo, Dept Urol, BR-05508 Sao Paulo, SP, BrazilFac Med ABC, Dept Urol, Sao Paulo, SP, BrazilUniv Los Andes, Dept Urol, Bogota, ColombiaEscuela Med Mil, Dept Urol, Mexico City, DF, MexicoHosp Clin Jose San Martin, Catedra Urol, Buenos Aires, DF, ArgentinaMae de Deus Ctr Hosp, Dept Urol, Porto Alegre, RS, BrazilUniv Fed Ciencias Saude Porto Alegre, Porto Alegre, RS, BrazilAC Camargo Hosp, Dept Urol, Sao Paulo, SP, BrazilHosp Clinico Fuerza Area Chile, Santiago, ChileInst Mexicano Seguro Social, Mexico City, DF, MexicoHosp Souza Aguiar, Dept Urol, Rio De Janeiro, RJ, BrazilComplejo Med Policial Churruca Visca, Serv Urol, Buenos Aires, DF, ArgentinaCtr Policlin Valencia Vina, Valencia, VenezuelaHosp Pablo Tobon Uribe, Medellin, ColombiaClin Indisa, Serv Urol, Providencia, ChileCtr Reabilitacao & Readaptacao Dr Henriqe Santill, Goiania, Go, BrazilHosp Univ Caracas, Serv Urol, Caracas, VenezuelaUniv Fed Ceara, Div Urol, Fortaleza, Ceara, BrazilUniv Fed Sao Paulo, EPM, Sao Paulo, SP, BrazilWeb of Scienc

    Brain metabolism and cerebrospinal fluid biomarkers profile of non-amnestic mild cognitive impairment in comparison to amnestic mild cognitive impairment and normal older subjects

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    Abstract\ud \ud Introduction\ud Mild cognitive impairment (MCI) is classically considered a transitional stage between normal aging and dementia. Non-amnestic MCI (naMCI) patients, however, typically demonstrate cognitive deficits other than memory decline. Furthermore, as a group, naMCI have a lower rate of an eventual dementia diagnosis as compared to amnestic subtypes of MCI (aMCI). Unfortunately, studies investigating biomarker profiles of naMCI are scarce. The study objective was to investigate the regional brain glucose metabolism (rBGM) with [18F]FDG-PET and cerebrospinal fluid (CSF) biomarkers in subjects with naMCI as compared to a control group (CG) and aMCI subjects.\ud \ud \ud Methods\ud Ninety-five patients were included in three different groups: naMCI (N = 32), aMCI (N = 33) and CG (N = 30). Patients underwent brain MRI and [18F]FDG-PET. A subsample (naMCI = 26, aMCI = 28) also had an assessment of amyloid-β, tau, and phosphorylated tau levels in the CSF.\ud \ud \ud Results\ud Both MCI groups had lower rBGM in relation to the CG in the precuneus. Subjects with naMCI showed decreased right prefrontal metabolism as well as higher levels of CSF amyloid-β relative to aMCI subjects.\ud \ud \ud Conclusion\ud While amnestic MCI subjects showed a biomarker profile classically related to MCI due to Alzheimer’s disease, naMCI patients illustrated a decrease in both prefrontal hypometabolism and higher CSF amyloid-β levels relative to the aMCI group. These biomarker findings indicate that naMCI is probably a heterogeneous group with similar precuneus hypometabolism compared to aMCI, but additional frontal hypometabolism and less amyloid-β deposition in the brain. Clinical follow-up and reappraisal of biomarkers of the naMCI group is needed to determine the outcome and probable etiological diagnosis.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) numbers 2011/18245-4 and 2009/17398-1 in BrazilCoordination for the Improvement of Higher Education Personnel (CAPES)/Brazi
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