Angular Momentum of the BTZ Black Hole in the Teleparallel Geometry

We carry out the Hamiltonian formulation of the three- dimensional gravitational teleparallelism without imposing the time gauge condition, by rigorously performing the Legendre transform. Definition of the gravitational angular momentum arises by suitably interpreting the integral form of the constraint equation Gama^ik=0 as an angular momentum equation. The gravitational angular momentum is evaluated for the gravitational field of a rotating BTZ black hole.Comment: 17 pages, no figures, v2: some misprints corrected, Ref.s added, Eq.s revised, submitted to General Relativity and Gravitatio

Solvability for a nonlinear coupled system of Kirchhoff type for the beam equations with nonlocal boundary conditions

In this paper, we investigate a mathematical model for a nonlinear coupled system of Kirchhoff type of beam equations with nonlocal boundary conditions. We establish existence, regularity and uniqueness of strong solutions. Furthermore, we prove the uniform rate of exponential decay. The uniform rate of polynomial decay is considered

Diferenciação de isolados bacterianos com base no gene de Fe-hidrogenases

O processo fermentativo de producao de H2 por microrganismos depende fundamentalmente da presenca de metaloenzimas designadas por hidrogenases. As hidrogenases sao enzimas envolvidas no metabolismo do H2, capazes de produzir ou consumir hidrogenio molecular, em processos relacionados com a transferencia de electroes e obtencao de energia. Elas catalisam a reaccao reversivel: H2 . 2H++ 2e- [1]. As hidrogenases dividem-se em classes filogeneticamente distintas, caracterizadas pelas diferentes subunidades ou dominios que acomodam o centro catalitico: as metalo-hidrogenases e as hidrogenases nao metalicas. As metalo-hidrogenases em particular podem ser divididas em dois tipos diferentes, conforme o conteudo metalico do seu centro catalitico: as que contem apenas ferro ([FeFe]-H2ases) e as que contem niquel e ferro ([NiFe]-H2ases), e que por vezes contem tambem selenio no seu centro catalitico ([NiFe(Se)]-H2ases) [2]. As [FeFe]-H2ases, existentes apenas em bacterias anaerobias e num pequeno numero de algas verdes, e em particular o gene hydA de [FeFe]-H2ases, que e o principal gene envolvido na producao de H2, sao considerados um biomarcador util para examinar a diversidade e distribuicao de microrganismos produtores de hidrogenio.

Traumatismo Crânio-Encefálico em Portugal: Tendências em Doentes Internados de 2000 a 2010

Introduction: Traumatic brain injury has a considerable socio-economic impact, being a major cause of morbi-mortality, often with permanent disability. We sought to characterize health resource utilization of adult traumatic brain injury patients in Portugal between 2000 and 2010. Material and Methods: Retrospective study of medical records of adult patients with ICD9 diagnostic code of traumatic brain injury included in the National Diagnosis Related Groups Database from 2000-2010. Descriptive statistical analysis was performed and trends during the decade were evaluated. Results: We analysed 72 865 admissions to 111 hospitals, 64.1% males, mean age 57.9 ± 21.8 years (18-107). We found a decrease in number of traumatic brain injury in younger patients and an increase in older ones. The number of traffic accidents decreased and the number of falls increased. There was an increase of moderate to severe traumatic brain injury admissions: 47.2% in 2000 / 80% in 2010. Patients admitted in Intensive Care have nearly doubled (15.8% vs 29.5%) as well as the number submitted to neurosurgical procedures (8.2% vs 15.2%). Total mortality increased from 7.1% to 10.6%. Discussion: The decrease of traumatic brain injury may be associated with the trauma prevention campaigns, road network improvement and health politics. The increase in mortality may be related to better pre-hospital care, enabling more severe cases to arrive in hospital alive, and although treated more frequently in Intensive Care and requiring more neurosurgical procedures, they end up having higher mortality. Also this may be due to an increase in patients' age and worse pre-morbid status. Conclusion: Traumatic brain injury in Portugal is changing. Although hospital admissions due to global traumatic brain injury have decreased, mortality rate has increased

Upper bound for the conductivity of nanotube networks

Films composed of nanotube networks have their conductivities regulated by the junction resistances formed between tubes. Conductivity values are enhanced by lower junction resistances but should reach a maximum that is limited by the network morphology. By considering ideal ballistic-like contacts between nanotubes we use the Kubo formalism to calculate the upper bound for the conductivity of such films and show how it depends on the nanotube concentration as well as on their aspect ratio. Highest measured conductivities reported so far are approaching this limiting value, suggesting that further progress lies with nanowires other than nanotubes.Comment: 3 pages, 1 figure. Minor changes. Accepted for publication in Applied Physics Letter

Cardiomiopatia de Takotsubo: uma complicação rara, mas grave, de crises epilépticas

Takotsubo cardiomyopathy (TKC) is a reversible, yet potentially fatal, syndrome triggered by stressful conditions, including seizures, with increasing recognition in clinical practice. We report a TKC in a patient with unexplained sinus tachycardia and troponin elevation after generalized seizures

Adult Tinea Capitis and Tinea Barbae in a Tertiary Portuguese Hospital: a 11-Year Audit

Adult tinea capitis and tinea barbae are nowadays considered uncommon in developed countries. Despite their potential for morbidity and healthcare costs, few series have attempted to characterise these infectious disorders. We conducted a cross-sectional study to analyse the epidemiological, clinical and mycological characteristics of adult tinea capitis and tinea barbae of a large tertiary centre in Southern Europe. All adult patients with a mycological-confirmed tinea capitis or barbae over a 11-year period (January 2008 to December 2018) were considered for the analysis. Concerning tinea capitis, 860 culture-confirmed diagnoses were made during this 11-year period, of which only 15 (1.5%) occurred in adults (15 patients). A disproportionately high number of patients were female and immunocompromised. Microsporum audouinii (20%) and Trichophyton rubrum (20%) were the most common isolates. Half of the cases were initially misdiagnosed. Regarding tinea barbae, 7 cases were diagnosed over this time period. Overuse of topical steroids was widespread in this population. Trichophyton rubrum was the infectious agent in all cases. Initial misdiagnosis was very common (43%). Adult tinea capitis and tinea barbae can still be observed in contemporary practice and remain a public health concern, with the immunosuppressed patient being particularly affected. Initial misdiagnosis is a common occurrence. Anthropophilic fungi are now the most common aetiologic agents of these infections, and they will probably continue to do so as the large urban centres expand peripherally. Awareness for this diagnosis is necessary to prevent unwarranted morbidity and costs.info:eu-repo/semantics/publishedVersio

Microlenses for stereoscopic image formation

This paper presents microlenses for integration on a stereoscopic image sensor in CMOS technology for use in biomedical devices. It is intended to provide an image sensor with a stereoscopic vision. An array of microlenses potentiates stereoscopic vision and maximizes the color fidelity. An array of optical filters tuned at the primary colors will enable a multicolor usage. The material selected for fabricating the microlens was the AZ4562 positive photoresist. The reflow method applied to the photoresist allowing the fabrication of microlenses with high reproducibility.This work was fully supported by the Portuguese Foundation for Science and Technology under the project FCT/PTDC/EEA-ELC/109936/2009