213 research outputs found
Statins and Parkinson's: A complex interaction
No abstract available
Estudo comparativo de soluções em alvenaria estrutural e betão armado
No setor da construção, a principal prioridade é a redução de custos relacionados com os processos
construtivos e a sua execução. Devido à crise económica global e ao crescimento da competitividade
do setor da construção, é necessário analisar outras opções que confiram boas práticas de construção,
cumprindo os requisitos definidos na regulamentação atual.
Este estudo aborda a temática de algumas das soluções construtivas normalmente utilizadas, focando aspetos
de normalização, custos, vantagens e desvantagens. É também apresentada uma avaliação comparativa
entre dois sistemas construtivos, alvenaria estrutural vs. betĂŁo armado, de uma moradia construĂda
ao abrigo de um projeto de investigação. Nessa avaliação é feita a apresentação do processo de conceção
modular e conceção estrutural para ambas as soluções em fase de projeto. Este estudo também apresenta
uma comparação de custos entre dois sistemas construtivos, nomeadamente a construção em alvenaria
estrutura vs. construção em betão armado.
Com o estudo realizado constatou-se que no projeto Ă© notĂłria a complexidade da alvenaria estrutural em
detrimento do betão armado. A alvenaria estrutural também apresenta limitações a eventuais alterações
executadas durante a vida Ăştil do edifĂcio. Relativamente Ă comparação de custos efetuada, os resultados
mostram que a construção em alvenaria estrutural é um processo tecnológico apropriado e a redução de
custos Ă© significativa
Planning and monitoring of patients for electrical cardioversion for atrial fibrillation
This study evaluated the waiting list for elective electrical cardioversion (ECV) for persistent atrial fibrillation (AF), focusing on when and why procedures were postponed. We compared the effects of management of the waiting list conducted by physicians versus management by nurse practitioners (NPs) and we evaluated the safety of our anticoagulating policy by means of bleeding or thromboembolic complications during and after ECV. Not all patients selected for ECV receive their treatment at the first planned instance due to a variety of reasons. These reasons are still undocumented. We evaluated 250 consecutive patients with persistent AF admitted to our clinic for elective ECV. Within 5 to 6 weeks, 186 of 242 patients (77%) received ECV. The main reason for postponing an ECV was an inadequate international normalised ratio (INR); other reasons included spontaneous sinus rhythm and switch to rate control. A total of 23 of the 147 patients (16%) managed by the research physician were postponed due to an inadequate INR at admission versus 4 out of 98 patients (4%) managed by NPs (p = 0.005) An inadequate INR is the main reason for postponing an ECV. Management of ECV by NPs is safe and leads to less postponing on admission
A review of elliptical and disc galaxy structure, and modern scaling laws
A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their
models to describe the radial distribution of stars in `nebulae'. This article
reviews the progress since then, providing both an historical perspective and a
contemporary review of the stellar structure of bulges, discs and elliptical
galaxies. The quantification of galaxy nuclei, such as central mass deficits
and excess nuclear light, plus the structure of dark matter halos and cD galaxy
envelopes, are discussed. Issues pertaining to spiral galaxies including dust,
bulge-to-disc ratios, bulgeless galaxies, bars and the identification of
pseudobulges are also reviewed. An array of modern scaling relations involving
sizes, luminosities, surface brightnesses and stellar concentrations are
presented, many of which are shown to be curved. These 'redshift zero'
relations not only quantify the behavior and nature of galaxies in the Universe
today, but are the modern benchmark for evolutionary studies of galaxies,
whether based on observations, N-body-simulations or semi-analytical modelling.
For example, it is shown that some of the recently discovered compact
elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to
appear in "Planets, Stars and Stellar
Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references
incl. many somewhat forgotten, pioneer papers. Original submission to
Springer: 07-June-201
Catheter ablation for AF improves global thrombotic profile and enhances fibrinolysis
© The Author(s) 2017. This article is an open access publication. The final authenticated version is available online at: https://doi.org/10.1007/s11239-017-1548-3Patients with atrial fibrillation (AF) are at increased risk of thrombotic events despite oral anticoagulation (OAC). Radiofrequency catheter ablation (RFCA) can restore and maintain sinus rhythm (SR) in patients with AF. To assess whether RFCA improves thrombotic status. 80 patients (71% male, 64 ± 12y) with recently diagnosed AF, on OAC and scheduled to undergo RFCA or DC cardioversion (DCCV) were recruited. Thrombotic status was assessed using the point-of-care global thrombosis test (GTT), before, and 4-6 weeks after DCCV and 3 months after RFCA. The GTT first measures the time taken for occlusive thrombus formation (occlusion time, OT), while the second phase of the test measures the time taken to spontaneously dissolve this clot through endogenous thrombolysis (lysis time, LT). 3 months after RFCA, there was a significant reduction in LT (1994s [1560; 2475] vs. 1477s [1015; 1878]) in those who maintained SR, but not in those who reverted to AF. At follow-up, LT was longer in those in AF compared to those in SR (AF 2966s [2038; 3879] vs. SR 1477s [1015; 1878]). RFCA resulted in no change in OT value, irrespective of rhythm outcome. Similarly, there was no change in OT or LT in response to DCCV, irrespective of whether SR was restored. Successful restoration and maintenance of SR following RFCA of AF is associated with improved global thrombotic status with enhanced fibrinolysis. Larger studies are required to confirm these early results and investigate whether improved thrombotic status translates into fewer thromboembolic events.Peer reviewedFinal Published versio
- …