580 research outputs found
Novel functionalized elongated titanate nanostructures for emergent pollutants photocatalytic degradation
The primary goal of this work was the preparation of new elongated titanate nanoparticles, like nanotubes (TNT) and nanowires (TNW), with improved ability for pollutants adsorption and photo(electro)catalytic degradation. TNT and TNW were prepared using a hydrothermal approach in alkaline medium, starting from TiO2 nanoparticles and amorphous precursors, respectively. The TNT/TNW were modified by ion-exchange and doping with metals (Co, Ru, and Fe/Mn), and by sensitization with Ag nanoparticles and ethylenediamine. The catalytic ability of these new materials for the pollutants photodegradation, including phenol, caffeine, theophylline, and dyes, was also investigated. The results showed that all modified TNT/TNW demonstrated excellent photocatalytic activity for the degradation processes studied. The sensitization process can improve the light absorption on the visible range and the ability for pollutants adsorption and photocatalytic degradation, due to the change imposed on the TNT/TNW surface. The metal modification can impose a light absorption shift to the visible range and/or the introduction of intermediary levels in the forbidden band, reducing the electron-hole (e-/h+) recombination. For the ethylenediamine sensitized samples, it was demonstrated that the N-species improves the photocatalytic activity. The results revealed h+ was mainly responsible for the hydroxyl radical formation, and the production of nitrogen oxidant species was proposed. The results for sensitized samples with Ag nanoparticles, Ag-HTNW, revealed the presence of Ag+ in the interlayers and Ag nanoparticles in the HTNW surface, and the h+ action with highly oxidant species enhances the photocatalytic performance. For the cobalt modified powders, depending on the synthesis methodology and Co/Ti ratio, the dopant can replace Na+ in the interlayers and/or substitute Ti4+ in lattice positions or sit in interstitial sites. The structure and optical behavior are dependent on the metal ions either substituting Ti4+ or replacing Na+.
For RuTNW sample, Run+ was detected in the crystalline structure replacing Ti4+ and in the interlayers replacing Na+, and for RuTNT it was only replacing Ti4+. The photocatalytic improvement of these materials was principally to recombination rate reduction, by metal incorporation. The utmost difference between these samples was related to the pollutants’ photodegradation mechanism and intermediates formation/degradation.
In this work, the influence of slight metal contaminations on the TNW structural, optical and photocatalytic behavior was also studied. FeMnTNW were obtained due to a reactants’ vestigial contamination. The modification occurred by Ti4+/Fe3+-Mn3+ substitution and by Na+ replacement in the interlayers.
The TNW/TNT immobilization in conductive films to be used in pollutants photo(electro)degradation, was also studied. Ru- and Co-modified TNW/TNT were immobilized on a conductive substrate by drop-casting method followed by 1,8- diaminocarbazole electropolymerization and were remarkably effective catalysts in pollutants photo(electro)degradation. The films’ reutilization showed that these are stable and can be used in successive degradation without performance loss
Role of microbiome in Multiple Sclerosis
Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, 2022, Universidade de Lisboa, Faculdade de Farmácia.A composição do microbioma já demonstrou desempenhar um importante papel em doenças autoimunes, em particular, em doenças neurodegenerativas. A Esclerose Múltipla é uma doença desmielinizante e autoimune, cuja etiologia ainda não está completamente esclarecida, embora existam vários fatores que contribuem para o desenvolvimento da doença. O eixo intestino-cérebro é de extrema importância na compreensão de doenças como a Esclerose Múltipla e na influência que o microbioma tem na patogénese da doença, tornando estes microorganismos de grande interesse. Ao compreender a importância da flora microbiana na modulação de respostas imunes, a modulação do microbioma pode ser uma abordagem terapêutica inovadora para doenças neurodegenerativas. O transplante de matéria fecal é um procedimento utilizado para restaurar o ambiente microbiano de doentes com infeções gastrointestinais recorrentes, mas a sua utilização no tratamento da Esclerose Múltipla tem tido um foco crescente. Estes estudos levaram a mais pesquisas sobre a modulação do microbioma como uma terapêutica para doenças neurodegenerativas, incluindo o tratamento sintomático e prevenção da progressão desta doença.The composition of the microbiome has demonstrated to play a role in autoimmune diseases, in particular, in neurodegenerative diseases. Multiple Sclerosis is a demyelinating, autoimmune disease whose aetiology is still not completely understood, although there are several factors that contribute to the development of the disease. The gut-brain axis is of extreme importance in the comprehension of diseases like Multiple Sclerosis and the influence
that the microbiome has in disease pathogenesis has made these microorganisms of great interest. By comprehending the importance of microbial communities in the modulation of immune responses, the modulation of the microbiome could potentially be an innovative therapeutic approach to neurodegenerative diseases. Faecal matter transplantation is a procedure used to restore the microbial environment of patients with recurrent gastrointestinal
infections, but its use in the treatment of Multiple Sclerosis has been of growing focus. These studies have led to more research on microbiome modulation as a therapy for neurodegenerative diseases, including symptomatic treatment and prevention of disease progression
A preocupante tricotomia na nutrição clínica e sua aplicação aos direitos humanos
Nutritional support is a major advance in medicine which has made it possible to feed all sick people unable to be orally fed. Failure to anticipate ethical and legal issues as part of the development of technologies such as this can be problematic. This conundrum has been dubbed «the troubling trichotomy» (T3) by the lead author.
El soporte nutricional es un gran avance de la medicina que ha permitido alimentar a todos los enfermos que no pueden ser alimentados por vía oral. Durante el desarrollo de tecnologías como esta, la falta de previsión de las cuestiones éticas y legales puede resultar problemática. El autor principal (T3) ha bautizado este enigma como “la tricotomía problemática”.
O suporte nutricional é um grande avanço na medicina que tem permitido alimentar todos os pacientes que não podem ser alimentados por via oral. Durante o desenvolvimento de tecnologias como esta, a falta de previsão das questões éticas e legais pode ser problemática. O autor principal (T3) batizou esse enigma de “Tricotomia Problemática”
Curvas de rotação de galáxias LSB em aproximação quase-newtoniana da Teoria da Relatividade Geral
Dissertação de mestrado apresentada ao Programa de Pós-Graduação em Física Aplicada da Universidade Federal da Integração Latino-Americana (PPGFISA-UNILA) como parte dos requisitos necessários para a obtenção do título de mestre em Física aplicada. Trabalho realizado sob orientação do Prof. Dr. Abraão Jessé Capistrano de SouzaDesde as observações de Bosma e Rubin na década de 1970, as curvas de rotação das galaxias compõem parte central de um dos principais problemas em discussão na astrofísica contemporânea. A indicação da aparente falta de matéria bariônica, decorrente das divergências em relação a previsão newtoniana, induziu à formulação de novos modelos como a hipótese da matéria escura ou modificações da dinâmica newtoniana. No presente trabalho, estudamos o problema por meio de uma aproximação da Relatividade Geral com a aplicação de condições de movimento lento à equação da geodésica, deixando intactas as equações de campo e a equação do desvio geodésico, sem impor as condições de campo fraco. Para a obtenção de um campo de velocidades, foi utilizada uma métrica estática de Weyl em disco fino, com a qual se testou a adequação do modelo a 25 galáxias de baixo brilho super cial (LSB).Since the observations of Bosma and Rubin in the 1970s, the rotation curves of the
galaxies are one of the main issues under discussion in contemporary astrophysics. The
indication of the apparent lack of baryonic matter, due to the divergences with newtonian
predictions, led to the formulation of new models, as the dark matter hypothesis or
modications of the newtonian dynamics. In the present work, we study the problem by
means of an approximation of General Relativity with low motion condition applied to
geodesic equation, leaving intact the field equations and the geodesic deviation equation,
without imposing the conditions of weak field. In order to obtain a velocity field, we
used a static Weyl thin-disc metric to test the suitability of the model to 25 low surface
brightness (LSB) galaxie
Electrochemical treatment of sanitary landfill leachates
Sanitary landfill leachate is one of the major environmental problems concerning water pollution, since it is a very complex wastewater containing different heavy metals, organic and inorganic compounds, some of them refractory and toxic, which possesses colour and odour. Optimal leachate treatment, in order to fully reduce the negative impact on the environment, is today a challenge, since the conventional treatment methods used are not enough to reach the level of purification needed. For this reason, several advanced technologies have been studied for the treatment of sanitary landfill leachates and among them electrochemical methods have received great attention. In fact, electrochemical technologies have shown high efficiency in the elimination of persistent pollutants and several studies have reported its application in wastewater treatment.
The objective of the work described in this thesis was to evaluate the application of two electrochemical methods, electrocoagulation and electrochemical oxidation, in the treatment of sanitary landfill leachates. Studies were performed with different leachate samples, collected at different sanitary landfill facilities, at different points of the treatment plants existed and in different seasons of the year. Different cell configurations and electrode materials were experimented. Operational variables such as applied current/potential, stirring, flow rate and electrolysis time were studied. Pollutants removal, mineralization and biodegradability indexes and energetic costs were also assessed.
The results obtained demonstrated that electrocoagulation and electrochemical oxidation are effective technologies to treat leachates from sanitary landfills. Depending on the leachate characteristics, electrochemical treatments can be applied as pre-treatment or post treatment of biological processes. For leachates with high content in organic matter, electrochemical oxidation was more effective when applied after the biological treatment, eliminating the refractory organic matter remaining. Energy consumptions of 15 and 21 W h (g COD)-1 were achieved at laboratory and semi-pilot scales experiments, respectively.
For leachates designated as “old” or with low biodegradability index, electrochemical oxidation process was more efficient when applied to the raw leachate, without any kind of pre-treatment. Chemical oxygen demand removals above 90% were achieved with energy consumptions of 78 W h (g COD)−1.
For leachates with a high amount of solids, the application of an electrocoagulation process before the electrochemical oxidation enhanced the treatment efficiency. Electrocoagulation assays performed led to reductions in organic load of 50% with energy consumptions of 2 W h (g COD)−1. Furthermore, the combined electrocoagulation/ electrochemical oxidation treatment, when applied to raw leachates, enhances the biodegradability of the organic pollutants, improving the performance of the subsequent biological process. An increase in the biodegradability index from 0.3 to 0.9 was attained for the combined assays performed, with chemical oxygen demand removals above 95%. Moreover, this combined treatment has the advantage of being able to use the simultaneous cathodic reduction to remove heavy metals from the leachate, since these processes reduce the metal ions by depositing them onto the cathode. However, when solids content is low, it is preferable to apply only the electrochemical oxidation process, since it does not have the disadvantage of sludge production.
The experiments using Ti/Pt/PbO2 anodes showed that this material can be successfully used for the treatment of sanitary landfill leachates, leading to lower energy consumptions than those obtained with boron doped diamond anodes. Both anode materials presented similar chemical oxygen demand removal kinetics and, despite boron doped diamond anodes yields higher mineralization indexes, Ti/Pt/PbO2 promotes higher levels of total and ammonia nitrogen removals
RTPatient - Platform for Managing Reminiscence Therapy Sessions and Patients
Tese de mestrado, Informática, Universidade de Lisboa, Faculdade de Ciências, 2022Dementia is an overall term that describes a group of symptoms associated with a decline in memory or other thinking skills severe enough to reduce a person’s ability to perform everyday activities. Reminiscence therapy is used to counsel and support older people with dementia. It shows results in an initial stage and is a treatment that tries to use all five senses — sight, touch, taste, smell and hearing, but most of the time is focused on sight (images) and hearing (music) — to help individuals with dementia remember events, people and places from their lives. The few existing technological platforms that support reminiscence therapy produce a collection of data that remains unchanged throughout time, sometimes only based on a set of generic pictures, where their acquisition is made in a non dynamic way. Our goal with this work is to build a digital platform that will help with the reminiscence therapy. It will allow caregivers to upload pictures to be used in sessions, gather generic pictures based on patients personal information, keep track of the patients evolution, as well as of their emotional reactions over time. It is important to keep track of those emotions to improve a session, since different images have different effects on the patient. Preventing from showing an image that provokes a bad reaction will not only help the person with dementia but the caregiver, by reducing the chance of irritability or even aggressiveness from the patient with dementia towards the caregiver. In this project we developed a digital platform, called RTPatient, to support PwD and their caregivers. With RTPatient we are able to insert or edit patients information, share the responsibility of gathering information, start a reminiscence therapy session or consult previous sessions. The platform has a login for each Caregiver, where they can see their list of patients and their details. The Caregiver can be a family member or a formal carer. After finishing our platform we did Usability tests, used the System Usability Scale (SUS) to measure the overall usability of the solution and asked for feedback to help us understand if the platform was easy to use and if it had all the needed functionalities. After analysing all the data and checking our SUS average score of 91.4, we can conclude that our platform was considered easy to use. Regarding the feedback we identified some small improvements to be done in future work, like a better positioning of some buttons. Another suggestion was the addition of a new functionality to add a list for the caregiver to see all the patients he used to take care of
E-Health individual adoption - empirical model based on UTAUT 2.
The future of health care delivery is becoming more citizen-centred, as today’s
user is more active, better informed and more demanding. The European Commission
is promoting online health services and, therefore, member states will need to boost
deployment and use of online services. This makes e-health adoption an important field
to be studied and understood.
This study applied the extended unified theory of acceptance and usage
technology (UTAUT2) to explain patients’ individual adoption of e-health. An online
questionnaire was administrated Portugal using mostly the same instrument used in
UTAUT2 adapted to e-health context. We collected 386 valid answers.
Performance expectancy, effort expectancy, social influence, and habit had the
most significant explanatory power over behavioural intention and habit and
behavioural intention over technology use. The model explained 52% of the variance in
behavioural intention and 32% of the variance in technology use.
Our research helps to understand the desired technology characteristics of ehealth.
By testing an information technology acceptance model, we are able to
determine what is more valued by patients when it comes to deciding whether to adopt
e-health systems or not
Studies on pharmaceuticals removal from water potential use of constructed wetlands systems
Pharmaceutical residues in the environment and their potential toxic effects have been recognized as one of the emerging research areas in environmental chemistry. Many reports are available in the literature about the detection of several of the most consumed pharmaceuticals, their metabolites and transformation products in effluents of domestic wastewater treatment plants (WWTPs) as well as surface and ground waters and even, in drinking waters worldwide. This situation can be attributed to the general inadequacy of conventional treatment processes used. in WWTPs in dealing with trace pollutants.
An option for removal of organic xenobiotics from WWTPs effluents is the implementation of constructed wetlands systems (CWS). In comparison with other tertiary or advanced treatment technologies, CWS present the advantage of being an essentially low-cost and low-maintenance technology. CWS have been already applied with success for the treatment of other organic xenobiotics, but their use for pharmaceuticals removal has been only scarcely tested. Moreover, these systems have been approached primarily as a "black-box", without a thorough understanding of the processes involved. The efficiency of CWS in the removal of pollutants can be significantly enhanced by using adequate support matrices with a greater capacity to retain contaminants by sorption phenomena, ionic exchange or other physico-chemical processes and plant species with high capacity to tolerate and remove pollutants froco contaminated waters.
The main goal, of this work was to evaluate the ability of a microcosm CWS to remove selected pharmaceuticals from domestic wastewater that has received secondary treatment.
The selection of the pharmaceuticals to be studied was based on the following criteria: data on consumption and presence in the environment, behavior in. WWTPs, and characteristics such as biodegradability, acid-base character, hydrophobicity and water solubility. Four pharmaceuticals were selected, in particular two acidic substances (ibuprofen, IB, and clofibric acid, CA), a neutral one (carbamazepine, CB) and another with an alkaline character (atenolol, AT). These are moderately lipophilic compounds, with the exception of AT, which is a somewhat hydrophilic substance. Among these, one of the compounds is biodegradable (IB), another one is only moderately biodegradable (AT), whereas the other two (CA and CB) are hardly biodegradable.
/RESUMO -
A qualidade da água é uma das grandes preocupações actuais em química analítica ambiental. Em particular, a ocorrência e destino de fármacos no ambiente aquático tem vindo a ser reconhecido como um dos problemas emergentes nesta área.
De facto, a frequente detecção de fármacos utilizados em medicina humana, seus metabolitos e produtos de transformação em efluentes de estações de tratamento de águas residuais urbanas (ETARs) bem como em águas naturais, superficiais e subterrâneas, e até mesmo em águas para consumo, tem demonstrado a existência de um problema real devido à crescente quantidade e diversidade de substâncias deste tipo que são excretadas e libertadas nos sistemas de recolha de efluentes líquidos urbanos. Como consequência da geralmente baixa eficiência de remoção destes contaminantes pelos processos de tratamento convencionais utilizados na maioria das ETARs, resulta que muitas destas substâncias acabam por ser descarregadas com os efluentes nos meios receptores hídricos e disseminadas pelos meios aquáticos.
As implicações resultantes desta descarga de fármacos no ambiente aquático sugerem a urgente necessidade de encontrar processos complementares ou alternativos para a sua remoção dos efluentes antes de alcançarem os cursos de água. A utilização de processos de tratamento terciário ou de afinação nas ETARs, como por exemplo a utilização de processos de membranas ou oxidação química, podem permitir o aumento das eficiências de remoção obtidas. No entanto, a implementação e manutenção deste tipo de processos têm custos elevados e são dificeis de adaptar para uma utilização em larga escala em ETARs.
Os leitos construídos de macrófitas (LCMs) têm surgido ultimamente como sistemas complementares ou, nalguns casos, alternativos de tratamento de águas residuais urbanas. Os LCMs, ou zonas húmidas construídas, são sistemas artificiais projectados e construidos para tirar partido do mesmo tipo de processos que ocorrem nas zonas húmidas naturais, utilizando vegetação, solos e colónias de microorganismos típicas destes sistemas, mas actuando de uma forma controlada e optimizada com o propósito de aplicação para tratamento de efluentes.
Os mecanismos de tratamento nos LCMs são extremamente diversificados, caracterizados por uma interacção complexa de processos fisicos, químicos e biológicos, que ocorrem ao nível das plantas, da matriz de suporte e dos microrganismos adaptados à toxicidade do efluente
Archaeological evidence for the dietary practices and lifestyle of 18th Century Lisbon, Portugal. Combined steroidal biomarker and microparticle analysis of the carbonized faecal remains
The study of the urban context in the contemporary center of Portugal’s capital city uncovered traces of daily lives that were abruptly interrupted and utterly transformed by the Great Lisbon Earthquake on the morning of 1 November 1755. Charred organic residue was recovered from a cylindrical vessel excavated from the storage area of the town house at the Rossio square. The archaeological sample was studied through a multi-analytical approach based on microstructural, elemental and biomolecular characterization by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR), variable pressure scanning electron microscopy coupled to energy dispersive X-ray spectroscopy (VP-SEM-EDS), and gas chromatography coupled with mass spectrometry (GC-MS). The residue was identified as human faeces collected in the ceramic vessel for disposal, and further analysis provided additional information about diet and the living conditions in the 18th century
- …