Inspeção e manutenção de torres de radiocomunicações

Relatório de Estágio para obtenção de grau de Mestre em Engenharia Civil Área de Especialização de EdificaçõesNa década de 90 verificou-se a expansão das redes de radiocomunicações, período em que as operadoras de serviço móvel apostavam em cobrir todo o território português com a melhor rede possível. Como consequência, verificou-se a implementação em grande escala de infraestruturas que acompanhassem as necessidades de rede. Passado este período, reconheceu-se a necessidade de manter estas infraestruturas em bom estado de conservação estrutural através de inspeções e manutenções periódicas e ensaios pontuais. Deste modo, a Vodafone Portugal, implementou um programa de inspeção e manutenção aplicável ao seu parque de torres de radiocomunicações. Este trabalho, que decorre de um estágio, desenvolvido nesta empresa e em continuidade com trabalhos anteriormente desenvolvidos, pretende ser um contributo e partilha de conhecimentos das ações e melhorias que vão sendo desenvolvidas nesta área.Abstract: In the 90s, radio networks have significantly expanded. During this period, mobile service companies intended to cover the entire Portuguese territory with the best possible network. As a result, there was a large-scale deployment of infrastructures to respond to the needs of the network. After this period, it was recognized there was a need to maintain these infrastructures in good structural conditions via periodic inspections, maintenance and occasional tests. Thus, Vodafone Portugal implemented an inspection and maintenance program, applicable to allits radio communication towers. This work, carried out within the framework of an internship in this company, and is in accordance with previous work developed, aims at contributing to knowledge sharing of actions and improvements that are being developed in this area

Anaplastic thyroid cancer

Globally, thyroid cancer accounts for 2 % of all cancer diagnoses, and can be classified as well-differentiated or undifferentiated. Currently, differentiated thyroid carcinomas have good prognoses, and can be treated with a combination of therapies, including surgical thyroidectomy, radioactive iodine therapy and hormone-based therapy. On the other hand, anaplastic thyroid carcinoma, a subtype of undifferentiated thyroid carcinoma characterized by the loss of thyroid-like phenotype and function, does not respond to either radioactive iodine or hormone therapies. In most cases, anaplastic thyroid carcinomas are diagnosed in later stages of the disease, deeming them inoperable, and showing poor response rates to systemic chemotherapy. Recently, treatment courses using multiple-target agents are being explored and clinical trials have shown very promising results, such as overall survival rates, progression-free survival and tumor shrinkage. This review is focused on thyroid carcinomas, with particular focus on anaplastic thyroid carcinoma, exploring its undifferentiated nature. Special interest will be given to the treatment approaches currently available and respective obstacles or drawbacks. Our purpose is to contribute to understand why this malignancy presents low responsiveness to current treatments, while overviewing novel therapies and clinical trials

Anaplastic thyroid cancer: how far can we go?

Globally, thyroid cancer accounts for 2 % of all cancer diagnoses, and can be classified as well-differentiated or undifferentiated. Currently, differentiated thyroid carcinomas have good prognoses, and can be treated with a combination of therapies, including surgical thyroidectomy, radioactive iodine therapy and hormone-based therapy. On the other hand, anaplastic thyroid carcinoma, a subtype of undifferentiated thyroid carcinoma characterized by the loss of thyroid-like phenotype and function, does not respond to either radioactive iodine or hormone therapies. In most cases, anaplastic thyroid carcinomas are diagnosed in later stages of the disease, deeming them inoperable, and showing poor response rates to systemic chemotherapy. Recently, treatment courses using multiple-target agents are being explored and clinical trials have shown very promising results, such as overall survival rates, progression-free survival and tumor shrinkage. This review is focused on thyroid carcinomas, with particular focus on anaplastic thyroid carcinoma, exploring its undifferentiated nature. Special interest will be given to the treatment approaches currently available and respective obstacles or drawbacks. Our purpose is to contribute to understand why this malignancy presents low responsiveness to current treatments, while overviewing novel therapies and clinical trials.This research was funded by Fundação para a Ciência e a Tecnologia (FCT) through the Project Reference UID/DTP/04138/2019.info:eu-repo/semantics/publishedVersio

Estudante online: que competências?

Tendo por cenário o Mestrado em Supervisão Pedagógica, oferecido pelo Departamento de Educação e Ensino a Distância da Universidade Aberta, o grupo de estudantes da edição de 2009-2011 desenvolveu uma investigação sobre as competências a exigir e a desenvolver por aqueles que querem aprender na modalidade online. Numa relação directa com esta problemática, estabeleceram princípios e delinearam questões frente a competências necessárias por aqueles que ensinam online. Pretendem, apenas, contribuir para a reflexão em torno de competências esperadas para a concretização do ensino e aprendizagem online.info:eu-repo/semantics/publishedVersio

Nanoformulation of seaweed eisenia bicyclis in albumin nanoparticles targeting cardiovascular diseases: In vitro and in vivo evaluation

Natural products, especially those derived from seaweeds, are starting to be seen as effective against various diseases, such as cardiovascular diseases (CVDs). This study aimed to design a novel oral formulation of bovine albumin serum nanoparticles (BSA NPs) loaded with an extract of Eisenia bicyclis and to validate its beneficial health effects, particularly targeting hypercholesterolemia and CVD prevention. Small and well-defined BSA NPs loaded with Eisenia bicyclis extract were successfully prepared exhibiting high encapsulation efficiency. Antioxidant activity and cholesterol biosynthesis enzyme 3-hydroxy-3 methylutaryl coenzyme A reductase (HMGR) inhibition, as well as reduction of cholesterol permeation in intestinal lining model cells, were assessed for the extract both in free and nanoformulated forms. The nanoformulation was more efficient than the free extract, particularly in terms of HMGR inhibition and cholesterol permeation reduction. In vitro cytotoxicity and in vivo assays in Wistar rats were performed to evaluate its safety and overall effects on metabolism. The results demonstrated that the Eisenia bicyclis extract and BSA NPs were not cytotoxic against human intestinal Caco-2 and liver HepG2 cells and were also safe after oral administration in the rat model. In addition, an innovative approach was adopted to compare the metabolomic profile of the serum from the animals involved in the in vivo assay, which showed the extract and nanoformulation's impact on CVD-associated key metabolites. Altogether, these preliminary results revealed that the seaweed extract and the nanoformulation may constitute an alternative natural dosage form which is safe and simple to produce, capable of reducing cholesterol levels, and consequently helpful in preventing hypercholesterolemia, the main risk factor of CVDs.info:eu-repo/semantics/publishedVersio

A valoração do dano corporal: ao abrigo da Portaria nº 377/2008 de 26 de maio, alterada pela Portaria nº 679/2009 de 25 de junho

- Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.- Localização na estante: 343.615(469) G249

Nanoformulations of a Triazene Analogue with Specific Affinity to Human Melanoma

Abstract Malignant melanoma remains an aggressive malignancy conferring a very poor prognosis and standard treatments have not demonstrated an overall survival benefits. The alkylating agents triazenes have been used for treatment of malignant melanoma. However, their lack of specificity toward tumor cells requires the urgent development of novel therapeutic strategies. Therefore, the main objectives of the present work were the use of a triazene prodrug, previously synthesized and adequately formulated in liposomes. This triazene prodrug has demonstrated in previous work to be a good substrate for tyrosinase, an enzyme that is overexpressed in melanoma cells. After optimization of liposome preparation conditions and selection of most appropriated lipid compositions, it was possible to achieve high incorporation efficiencies. The association of this prodrug in liposomes, primarily relies in the possibility of solving solubility problems, increasing internalization in melanoma cell lines, protecting the molecule from premature degradation and enhancing its therapeutic index. Prodrug in free and liposomal forms demonstrated a high stability in the presence of human plasma, at 37°C. The in vitro tests, performed in human melanoma cell lines, demonstrated that the incorporation of TPD in liposomes was able to potentiate the cytotoxic effect of this triazene prodrug. The IC 50 for the prodrug in free form was superior to 125 µM, whereas in the liposomal form this value ranged from 13 to 22 µM being dependent on the lipid composition. The obtained results represent an excellent approach to fight malignant melanoma

Nanoformulations of a potent copper-based aquaporin inhibitor with cytotoxic effect against cancer cells

Aim: Development of liposomal formulations of Cuphen, a potent copper-based aquaporin inhibitor with therapeutic potential against melanoma and colon cancer. Materials &amp; methods: Cuphen was incorporated into liposomes using the dehydration–rehydration method. The ability of Cuphen to induce cancer cell death was evaluated by MTS and ViaCount assays. In vivo toxicity studies were performed in BALB/c mice. Results: In vitro studies illustrated the antiproliferative effects of Cuphen in different cancer cell lines, in free form or after incorporation into liposomes. In vivo studies revealed no toxic effects after parenteral administration of Cuphen liposomes. Conclusions: Cuphen liposomes are highly attractive to be further tested in murine models due to the possibility of stabilizing and specifically deliver this metallodrug to tumor sites. </jats:p

Liposomes as a nanoplatform to improve the delivery of antibiotics into Staphylococcus aureus biofilms

Research Areas: Pharmacology & PharmacyABSTRACT - Staphylococcus aureus biofilm-associated infections are a major public health concern. Current therapies are hampered by reduced penetration of antibiotics through biofilm and low accumulation levels at infected sites, requiring prolonged usage. To overcome these, repurposing antibiotics in combination with nanotechnological platforms is one of the most appealing fast-track and costeffective approaches. In the present work, we assessed the potential therapeutic benefit of three antibiotics, vancomycin, levofloxacin and rifabutin (RFB), through their incorporation in liposomes. Free RFB displayed the utmost antibacterial effect with MIC and MBIC50 below 0.006 µg/mL towards a methicillin susceptible S. aureus (MSSA). RFB was selected for further in vitro studies and the influence of different lipid compositions on bacterial biofilm interactions was evaluated. Although positively charged RFB liposomes displayed the highest interaction with MSSA biofilms, RFB incorporated in negatively charged liposomes displayed lower MBIC50 values in comparison to the antibiotic in the free form. Preliminary safety assessment on all RFB formulations towards osteoblast and fibroblast cell lines demonstrated that a reduction on cell viability was only observed for the positively charged liposomes. Overall, negatively charged RFB liposomes are a promising approach against biofilm S. aureus infections and further in vivo studies should be performed.info:eu-repo/semantics/publishedVersio

Antimicrobial activity of prophage endolysins against critical Enterobacteriaceae antibiotic-resistant bacteria

Enterobacteriaceae species are part of the 2017 World Health Organization antibiotic-resistant priority pathogens list for development of novel medicines. Multidrug-resistant Klebsiella pneumoniae is an increasing threat to public health and has become a relevant human pathogen involved in life-threatening infections. Phage therapy involves the use of phages or their lytic endolysins as bioagents for the treatment of bacterial infectious diseases. Gram-negative bacteria have an outer membrane, making difficult the access of endolysins to the peptidoglycan. Here, three endolysins from prophages infecting three distinct Enterobacterales species, Kp2948-Lys from K. pneumoniae, Ps3418-Lys from Providencia stuartii, and Kaer26608-Lys from Klebsiella aerogenes, were purified and exhibited antibacterial activity against their specific bacterium species verified by zymogram assays. These three endolysins were successfully associated to liposomes composed of dimyristoyl phosphatidyl choline (DMPC), dioleoyl phosphatidyl ethanolamine (DOPE) and cholesteryl hemisuccinate (CHEMS) at a molar ratio (4:4:2), with an encapsulation efficiency ranging from 24 to 27%. Endolysins encapsulated in liposomes resulted in higher antibacterial activity compared to the respective endolysin in the free form, suggesting that the liposome-mediated delivery system enhances fusion with outer membrane and delivery of endolysins to the target peptidoglycan. Obtained results suggest that Kp2948-Lys appears to be specific for K. pneumoniae, while Ps3418-Lys and Kaer26608-Lys appear to have a broader antibacterial spectrum. Endolysins incorporated in liposomes constitute a promising weapon, applicable in the several dimensions (human, animals and environment) of the One Health approach, against multidrug-resistant Enterobacteriaceae.F.F.V. was funded by Fundação para a Ciência e a Tecnologia (FCT) through a project grant (PTDC/BTM-SAL/28978/2017) that supported this work. The work is partially supported by National funds from FCT, projects UIDB/04138/2020, UIDP/04138/2020, UIDB/00211/2020 and UIDB/04046/2020 (DOI https://doi.org/10.54499/UIDB/0404 6/2020)info:eu-repo/semantics/publishedVersio