Vision-based hand Wheel-chair control

Several studies have shown that people with disabilities benefit substantially from access to a means of independent mobility and assistive technology. Researchers are using technology originally developed for mobile robots to create easier to use wheelchairs. With this kind of technology people with disabilities can gain a degree of independence in performing daily life activities. In this work a computer vision system is presented, able to drive a wheelchair with a minimum number of finger commands. The user hand is detected and segmented with the use of a kinect camera, and fingertips are extracted from depth information, and used as wheelchair commands

Detecting traces of 17α-ethinylestradiol in complex water matrices

PTDC/FIS-NAN/0909/2014 UID/FIS/00068/2019Hormones have a harmful impact on the environment and their detection in water bodies is an urgent matter. In this work, we present and analyze a sensor device able to detect traces of the synthetic hormone 17α-ethinylestradiol (EE2) below 10−9 M in media of different complexities, namely, ultrapure, mineral and tap waters. This device consists of solid supports with interdigitated electrodes without and with a polyethylenimine (PEI) and poly (sodium 4-styrenesulfonate) (PSS) layer-by-layer film deposited on it. Device response was evaluated through capacitance, loss tangent and electric modulus spectra and the data were analyzed by principal component analysis method. While the three types of spectra were demonstrated to be able to clearly discriminate the different media, loss tangent spectra allow for the detection of EE2 concentration, with a sensitivity of −0.072 ± 0.009 and −0.44 ± 0.03 per decade of concentration, for mineral and tap water, respectively. Detection limits values were found to be lower than the ones present in the literature and presenting values of 8.6 fM (2.6 pg/L) and of 7.5 fM (22.2 pg/L) for tap and mineral waters, respectively. Moreover, the obtained response values follow the same behavior with EE2 concentration in any medium, meaning that loss tangent spectra allow the quantification of EE2 concentration in aqueous complex matrices.publishersversionpublishe

Sondas moleculares para a deteção de placas β-amilóide na doença de Alzheimer

The formation of amyloid structures is a neuropathological feature that characterizes several neurodegenerative disorders, such as Alzheimer´s and Parkinson´s disease. Up to now, the definitive diagnosis of these diseases can only be accomplished by immunostaining of post mortem brain tissues with dyes such Thioflavin T and congo red. Aiming at early in vivo diagnosis of Alzheimer´s disease (AD), several amyloid-avid radioprobes have been developed for b-amyloid imaging by positron emission tomography (PET) and single-photon emission computed tomography (SPECT). The aim of this paper is to present a perspective of the available amyloid imaging agents, special those that have been selected for clinical trials and are at the different stages of the US Food and Drugs Administration (FDA) approval.RESUMO: A formação de estruturas amilóides é uma característica neuropatológica comum nas várias doenças neurodegenerativas, como a doença de Alzheimer e de Parkinson. Até à data, o diagnóstico destas doenças apenas é conseguido post mortem por estudos histoquímicos com corantes, como a Tioflavina T e o vermelho do congo. Durante os últimos anos têm sido desenvolvidos vários compostos com afinidade para agregados de ß-amilóide para visualização dessas estruturas por tomografia de emissão de positrões (PET) e tomografia computadorizada de emissão de fotão único (SPECT). Neste trabalho pretendemos apresentar as principais sondas radioativas com potencial para imagiologia de estruturas amilóides, em especial aquelas que entraram em ensaios clínicos e se encontram em diferentes etapas de aprovação pela FDA

Gestão e manutenção de múltiplos terminais em redes de próxima geração

Este artigo propõe a criação de uma arquitetura que permita ao utilizador efetuar uma gestão dos seus dispositivos de comunicação por forma a aceder aos serviços contratados e proporcionar a mobilidade de sessão e identidade. Neste sentido foi desenvolvida uma arquitetura que oferece ao utilizador uma visão unificada de todos os seus dispositivos de comunicação e assim, disponibilizar uma forma simples e inovadora de gerir os dispositivos e a informação pessoal de cada utilizador. Esta arquitetura proporciona a mobilidade de terminal, bem como a mobilidade de identidade no mesmo dispositivo e entre dispositivos diferentes, oferecendo assim uma utilização mais eficiente dos recursos disponíveis. Com o propósito de testar a arquitetura elaborada, foram efetuados testes funcionais que demonstram que as especificações inicialmente propostas foram cumpridas. Com base nos testes efetuados, foi realizada uma avaliação do impacto no utilizador que a arquitetura induz, concluindo-se que esta solução é uma mais valia para o utilizador, tanto nas funcionalidades como na usabilidade

Optimization and kinetic study of esterification reaction of oleic acid using [HMIM]HSO4 as catalyst

Biodiesel Biodiesel is an alternative fuel to petrodiesel. It can be produced from a wide range of raw materials such as vegetable oils and animal fats. Yet, the use of sources that do not compete with the food market, such as waste cooking oils - which usually feature high levels of free fatty acids (FFA’s), can lead to problems in the process of biodiesel production through alkaline transesterification. Therefore, new methodologies to successfully apply acidic oils need to be developed.info:eu-repo/semantics/publishedVersio

Pharmaceutical drugs as emerging pollutants in aqueous media of Northeast Portugal

Emerging pollutants are potentially toxic substances that although found in very small concentrations can produce hazard effects to the environment. Due to their very small concentrations they are not yet included in the water quality monitoring programs neither in national or international environmental control regulations. Pharmaceutical and Personal Care Products (PPCPs) represent an important group of emerging pollutants owing to increased worldwide consumption and to their inherent capacity to induce physiological harmful effects in very low doses, which raises several concerns related with the potential adverse effects on humans, animals and environmental systems. In this work, it will be presented the development and validation of a complete experimental methodology proposed for the monitoring of pharmaceutical drugs. The method is based on solid phase extraction (SPE) followed by analysis with high performance liquid chromatography with a diode array detector (HPLC-DAD). Experimental results obtained with two different columns will be presented. An analytical Nucleosil 100-5 C18 column, 150 mm x 4.6 mm, obtained from Macherey-Nagel for compounds with lower pKa values and a SiliaChrom XT C18 column, 4.6 mm x 250 mm, obtained from SiliCycle for compounds with higher pKa values. The method is validated by the analysis of real aqueous matrices samples obtained from different water media sources, such as, swimming pools, rivers and wastewater treatment plants. To extend the scope of the analytical method and thus obtain a broader study, several drugs were selected, belonging to five different pharmacological classes: non-steroidal anti-inflammatory (ibuprofen, acetylsalicylic acid, ketoprofen, naproxen and diclofenac), analgesic (paracetamol), antibiotic (sulfamethoxazole), an anticonvulsant (carbamazepine) and a central nervous system stimulator (caffeine). These compounds were selected due to their high level of use and medical prescription and, consequently, leading to a high probability of environmental contamination.info:eu-repo/semantics/publishedVersio

Biomass-based residues valorization for the removal of sertraline from waters by adsorption

Pharmaceutical drugs reach the environment through several anthropogenic sources being scattered and accumulated across flora, fauna and all types of aquifers. Many of these compounds are intensively worldwide medical prescribed for the relief of most common diseases related with modern society, such as hormones, antidepressants, analgesics, antibiotics, anti-inflammatories, among others. Sertraline is a pharmaceutical drug used for the relief of depressive severe situations. Recent studies refer that some compounds belonging to this pharmaceutical class of drugs, despite of its very low level of concentration in water can be responsible for several and severe side-effects in the environmental fauna and flora based on toxicity and risk predictions.info:eu-repo/semantics/publishedVersio

Valorization of used cooking oils through ionic liquid catalyzed biodiesel conversion processes

Biodiesel is defined as a natural and renewable substitute for fossil fuels and can be produced through the transesterification or by esterification reaction of free farry acids of a vegetable oil, animal fat or waste cooking ois, with an alcohol, usuallt methanol or ethanol in the presence of homogeneous, heterogeneous or enzymatics catalystsinfo:eu-repo/semantics/publishedVersio

Valorization of waste cooking oils through conversion processes catalyzed by choline hydroxide

Biodiesel can be defined as mono-alkyl esters of long-chain fatty acids produced from vegetable or animal oils and alcohol with or without a catalyst. It can be produced by esterification of fatty acids or transesterification of triglycerides with short chain alcohols, such as methanol and ethanol. Methanol is used mainly due to its lower cost compared with other alcohols, so biodiesel most commonly refers to fatty acid methyl esters (FAMEs).The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020).info:eu-repo/semantics/publishedVersio

Study of Biodiesel Production through Esterification Catalysed by Imidazolium-based Ionic Liquids

Biodiesel is an alternative diesel fuel which is industrially produced from vegetable oils and animal fats, by transesterification reactions. Thus, currently most commercial biodiesel is produced from oils, using alkaline catalysts. On the other hand, conventional mineral acid catalysts like sulfuric acid, are commonly used for catalyzing esterification reactions of fatty acids which also produce biodiesel. However, Ionic Liquids (ILs) offer an alternative solution to classical homogeneous catalysts, because it can be recycled and reused in subsequent runs after recovery steps. An IL is a molten salt consisting of a cation and an anion, with low melting temperature. In this study, a Brønsted acidic IL, 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM][HSO4]) was used as a catalyst in the esterification of oleic acid with methanol into biodiesel. The effect of different operation parameters such as oleic acid to methanol molar ratio, amount of catalyst, reaction temperature, and reaction time were tested. The optimal conditions for esterification of oleic acid were experimentally determined at 1/10 for oleic acid/methanol molar ratio, 2.5 %wt for the amount of catalyst, a reaction time of 4 h and reaction temperature of 90oC. The Fatty Acid Methyl Esters (FAMEs) content was analyzed using Gas Chromatography.info:eu-repo/semantics/publishedVersio