312 research outputs found
Avaliação dos efeitos e interações de nitratos e salinidade em Echinogammarus meridionalis, isolados e em misturas
Mestrado em Toxicologia e EcotoxicologiaFreshwater ecosystems are among the world's most vulnerable ecosystems to climate change. These climatic changes have affected negatively the ecosystems, with the mean sea level rise leading to saline intrusion into freshwater ecosystems. Additionally, intensive agricultural practices and livestock production have been the cause of high concentrations of nitrates in groundwater and soil in various parts of the world. Due to these disturbances, namely in aquatic ecosystems, and imbalances, the variables salinity and nitrates were studied separately and combined (a more realistic scenario for ecosystems). The objective of this work was to evaluate the tolerance of Echinogammarus meridionalis to each of the selected variables seperately and in combination (mixture). The organisms were exposed to different concentrations for 96 hours. No food was given during the exposure period. Every day, mortality and physico-chemical parameters, such as conductivity, pH, oxygen saturation and temperature were recorded. At the end of each test, the organisms were separated into males and females and their body lengh measured. The LC50 of the acute toxicity tests for salinity was 25.38 ± 0.33 g L-1 and for the nitrate assays the LC50 resulting from the first collection of organisms was 121.59 ± 11.71 NO3-N L-1 and for the second collection the LC50 was of 116.99 ± 3.67 NO3-NL-1. The toxicity tests of the binary mixtures salinity and nitrate showed an antagonistic pattern at low concentrations in the S/A model (synergism /antagonism) and in the DL model (Dose Level deviation) there was antagonism at low concentrations and synergism at high concentrations. The results obtained in this work suggest a great tolerance to the salinity, hence it is expected that these Portuguese amphipods will be able to adapt to the climatic changes. Regarding nitrate tolerance, there was also a high resistance of the organisms in realistic concentrations and higher concentrations. The binary combinations of the mixture have an antagonistic effect at low concentration, thus suggesting a good adaptability of that organism to these environmental disturbances. When carrying out environmental biomonitoring studies in Portugal, it is useful to use native species rather than model species, since they play a crucial ecological role in the inherent ecosystem and the information obtained becomes more reliable and realistic.Os ecossistemas de água doce são dos ecossistemas mais vulneráveis do planeta às alterações climáticas. Estas mudanças climáticas têm vindo a provocar vários efeitos nos ecossistemas, entre eles, o aumento do nível médio do mar que poderá levar à intrusão salina em cursos de água doce. Por outro lado, as práticas agrícolas intensivas e a produção animal fez com que fossem atingidas concentrações elevadas de nitratos nas águas subterrâneas e nos solos, em várias zonas do planeta. Assim, devido a estas perturbações e desequilíbrios que se têm verificado nos ecossistemas, em particular nos ecossistemas aquáticos, estudou-se as variáves salinidade e concentratação de nitratos, isoladas e em mistura (cenário mais realista dos ecossistemas). O objetivo do trabalho focou-se em avaliar a tolerância de Echinogammarus meridionalis à variação de cada uma das variáveis e à sua variação conjunta. Durante 96 horas, os organismos foram expostos a diferentes concentrações. Os organismos não foram alimentados durante o período de exposição. Todos os dias, a mortalidade e os parâmetros físico-químicos, tais como a condutividade, pH, concentração de oxigénio e temperatura foram registados. No final de cada ensaio, os organismos foram separados em machos e fêmeas e foi determinado o comprimento do corpo. O LC50 dos testes de toxicidade aguda para a salinidade foi de 25.38 ± 0.33g L-1 e para os ensaios de nitratos o LC50 resultante da primeira amostragem de organismos foi de 121.59 ± 11.71 mg NO3-N L-1 e para a segunda amostragem, o LC50 foi de 116.99 ± 3.67 mg NO3-N L-1. Os ensaios de toxicidade da mistruras binárias de salinidade e nitratos evidenciou um padrão antagonista em baixas concentrações no modelo S/A (sinergismo/antagonismo) e no modelo DL (desvio do nível da dose) verificou-se antagonismo em concentrações baixas e sinergismo em concentrações altas. Os resultados obtidos neste trabalho mostram uma grande tolerância à salinidade, assim espera-se que estes anfípodes portugueses se consigam adaptar às mudanças climáticas. Relativamente à tolerância aos nitratos, houve também uma resistência alta dos organismos a concentrações ambientais realistas e concentrações mais elevadas. As combinações binárias das misturas um efeito antagonista em baixa concentração, sugerindo assim uma boa adaptabilidade desse organismo a esses distúrbios ambientais. Ao realizar estudos de biomonitorização ambiental em Portugal, é útil o uso de espécies nativas em vez de espécies modelo, pois desempenham um papel ecológico relevante nos ecossistemas inerentes, e as informações obtidas acabam por ser mais confiáveis e realistas
Validity and reliability of the reduced Portuguese version of the web based learning environment inventory
A utilização de instrumentos padronizados de avaliação, traz consigo uma dimensão de fidelidade e validade estatística que permitem um outro olhar sobre diversos aspectos relacionados com a avaliação de ambientes de aprendizagem, complementando e enriquecendo as abordagens de carácter mais qualitativo. Nesse sentido, têm sido desenvolvidos e validados em vários países, inquéritos por questionário, com o objectivo de recolher informações para avaliação dos ambientes virtuais de aprendizagem. Em pesquisas anteriores foi já debatida a inexistência de um instrumento desta natureza, validado na língua portuguesa. Este estudo pretende colmatar esta lacuna, sendo apresentado em detalhe o processo de tradução,
adaptação e validação da versão reduzida do Web Based Learning Environment Inventory.The use of standardized assessment instruments, brings a dimension of reliability
and validity that allows a different view on various aspects related to the assessment of
learning environments, complementing and enriching the more qualitative character of
other approaches. In this topic, questionnaire surveys, have been developed and validated
in several countries, with the aim of collecting information for evaluation of virtual learning
environments. It has already been discussed, in previous works, the absence of such an
instrument, validated for the Portuguese language. This study aims to fill this gap, presenting in detail the process of translation, adaptation and validation of the Portuguese reduced
version of the Web Based Learning Environment Inventory
Metals transfer from tobacco to cigarette smoke: Evidences in smokers’ lung tissue
Tobacco use kills millions of people every year around the world. The current level of 11 metals in tobacco was determined and their transfer rate to cigarette smoke was calculated as the difference between the total metal content in cigarettes and the amount present in its ashes. The metals content was also determined in the lung tissue of smokers and non-smokers in order to evaluate the marks that smoking leaves in this tissue. Metals content in tobacco ranged from less than 1μg/g (Co, Cd, Pb, As and Tl) to several hundreds of μg/g (Al, Mn and Ba). The highest transfer rate from tobacco to cigarette smoke was found for Tl (85-92%) and Cd (81-90%), followed by Pb (46-60%) and As (33-44%). Significantly higher levels of As, Cd and Pb were found in the lung tissue of smokers compared to non-smokers, showing that smoking results in an increase of these metals in the lungs and that they contribute to the carcinogenic potential of cigarette smoke. This study presents important data on current metals content in tobacco and its transference to cigarette smoke and provides evidence of their accumulation in smokers' lung tissue.info:eu-repo/semantics/publishedVersio
Tablet splitting: counselling the patients regarding techniques and tablet format
Tablet splitting consists in subdividing a tablet in order to facilitate its intake or to provide smaller doses, although its efficacy depends on many factors, such as tablet shape, size, splitting technique/device and patient ability. This technique is commonly used in households. Problems associated with this technique are mainly due to the lack of ability to obtain equal parts after breaking the tablet, either due to physical characteristics or the patient´s ability to do so[3], and the loss of mass due to crumbles.info:eu-repo/semantics/publishedVersio
Impact of the first wave of the COVID-19 outbreak on mental health and psychiatric drug use among portuguese pharmacy professionals
The COVID-19 outbreak was considered a pandemic by the World Health Organization on March 11, 2020 [1]. This outbreak has raised public health problems, bringing with it several implications both on physical and psychological level, in particular for health professionals on the front line of the pandemic, for the greater risk of infection [2,3]. In this sense, it is pertinent to evaluate how the COVID-19 outbreak had implications on the mental health and in the consumption of psychotropic drugs in Portugal, and among pharmacy professionals.info:eu-repo/semantics/publishedVersio
Pharmacy professionals as providers of rapid testing for HIV infection screening
Portugal continues to have one of the highest HIV rates in the European Union. More than 20% of the infected population is unaware of the state of their infection and may unknowingly contribute to the spread of the disease. In addition, those who are not aware that they are infected, loose the opportunity to receive treatment that prolongs life at the onset of infection, and helps to reduce HIV / AIDS-related racial / ethnic health disparities. The inclusion of rapid HIV screening tests in community pharmacies may improve the detection of undiagnosed infections. Pharmacies are valuable partners in health promotion efforts. They can be an accessible health resource for the inclusion of HIV testing, increasing the availability, convenience, and accessibility of these testing services. However, concerns have been raised, by the public and health professionals, regarding the readiness of community pharmacies to provide such tests and the willingness and preparation of pharmacy professionals to act as providers of rapid testing for HIV infection screening.info:eu-repo/semantics/publishedVersio
Hardware-Backed Confidential Blockchain
Tese de Mestrado, Engenharia Informática, 2022, Universidade de Lisboa, Faculdade de CiênciasIn the last few years, distributed computing has shifted towards execution using adversarial environments, mostly due to the rising costs of owning proprietary data centers. Due to privacy concerns, confidentiality guarantees are now es- sential to distribute computation of sensitive information. As such, this thesis focuses on those demands, delivering Con-BFT, a SMR-BFT protocol with confidentiality guaran- tees, using Intel SGX primitives, which allow for trusted execution. This trusted execution also allows for equivocation prevention, which can be used to improve the underly- ing consensus protocol, creating a more efficient SMR-BFT framework, while also providing a layer of confidentiality over the stored user-driven information. This thesis focuses on a possible solution for developing such a protocol, evaluating its overall level of usability for practical everyday use, and how Intel SGX affects the development of similar systems
Dysphagia in the Elderly and its Implications in the Administration of Oral Dosage Forms
Introduction: Dysphagia is defined as difficulty in swallowing and is more prevalent in advanced ages. To overcome this difficulty, the elderly resort to altering the physical form of the medication, resulting in consequences for themselves and for the therapy.info:eu-repo/semantics/publishedVersio
Ketamine antidepressant properties: a systematic review of clinical trials
Ketamine has been used to provide a rapid and persistent antidepressant effect in patients with treatment-resistant depression. This drug reverses depressive symptoms by blocking N-methyl-D-Aspartate receptors, which causes a downstream effect on glutamatergic system. The main goal of this work consisted in a systematic review of the antidepressant and adverse events of Ketamine in patients with treatment-resistant depression. Keywords were defined with PICO´s strategy and systematic review was performed by using the PUBMED database. After inclusion and exclusion criteria, a total of 21 articles were included. Results showed a rapid antidepressant action from the resynchronization of neural circuits upon Ketamine use. However, this drug was also associated with several induced side-effects, including changes in blood pressure, dissociative symptoms, headache, nausea and vomits. Different routes of administration and ketamine metabolites may be used to help to overcome some of the induced side-effects.info:eu-repo/semantics/publishedVersio
Implementação de metodologias blended-learning no ensino da farmacoterapia baseado em simulações
A incorporação de actividades de formação à distância por instituições de ensino superior é considerada um importante contributo para a criação de novas oportunidades de ensino tanto ao nível de formação inicial como da formação contínua. No campo da educação e formação clínica, os educadores e os clínicos vêm progressivamente reconhecendo o potencial das TIC para efeitos de aprendizagem, prática e avaliação de conhecimentos. Na Medicina e na Enfermagem, são prolíficos os trabalhos que ilustram a adaptação das componentes tecnológicas e dos métodos pedagógicos, contudo, tanto quanto foi possível indagar na área
da Farmácia, os exemplos internacionais são escassos, e nulos a nível nacional. Nesse sentido
este projecto destina-se a avaliar as necessidades subjacentes à implementação de um modelo de b-learning no ensino da Farmacoterapia baseada em Simulações, criá-lo, implementá-lo e por fim avaliar o desempenho do aluno e a sua motivação.The incorporation of distance learning activities by institutions of higher education is considered an important contribution to creating new opportunities for teaching at both initial and continuing training. In the field of and clinical training and education, educators and clinicians are increasingly recognizing thepotential of ICT for learning practices and assessment. In Medicine and Nursing, the works that illustrate the adaptation of technological components and teaching methods are prolific, however, when we look at the Pharmaceutical Education area, the international examples are scarce, and void at the national level. In that sense this project is intended to assess the needs underlying the implementation of amodel of blended learning in the teaching of pharmacotherapy based on simulations, create it, implement it and finally evaluate student performance and motivation
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