882 resultados para trihydrogen cation (H3 )
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Dissertao apresentada para obteno do Grau de Doutor em Engenharia Qumica Pela Universidade Nova de Lisboa,Faculdade de Cincias e Tecn
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Tri-and hexa-cyanoethyl functionalized 17-(L-1) and 42-membered (L-2) macrocyclic compounds were obtained by [1 + 1] (for L-1) or [2 + 2] (for L-2) cyclocondensation of the corresponding dialdehyde and diethylenetriamine, followed by hydrogenation by KBH4 and subsequent cyano-functionalization with acrylonitrile. They react with silver nitrate, leading to the formation of [AgL1](NO3) (1) and of the metalorganic coordination polymers [Ag-2(NO3)(2)L-1](n) (2) and {[Ag2L2](NO3)(2)}(n) (3). The complexes were characterized by elemental analysis, H-1 NMR, C-13 NMR, IR spectroscopies, and ESI-MS; moreover, L-2, 1, 2 and 3 were also characterized by single crystal X-ray diffraction. The metal cation in 1 is pentacoordinated with a N3O2 coordination environment; in 2, the metal cations display N4O2 octahedral and N2O3 square-pyramid coordination and in 3 they are in square-planar N-4 sites. In 1, the ligand acts as a pentadentate chelator, and in the other two cases, the ligands behave as octadentate chelators in a 1 kappa N-3:kappa O-2,2 kappa N,3 kappa N,4 kappa N (in 2) or 1 kappa N-3,2 kappa N-3,3 kappa N,4 kappa N fashion (in 3). The cyanoethyl strands of the ligands are directly involved in the formation of the 2D frameworks of 2 and 3, which in the former polymer can be viewed as a net composed of hexametallic 36-membered macrocyclic rings and in the latter generates extra hexametallic 58-membered cyclic sets that form zig-zag layers. The thermal analytical and electrochemical properties of these silver complexes were also studied.
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A new family of eight ruthenium(II)-cyclopentadienyl bipyridine derivatives, bearing nitrogen, sulfur, phosphorous and carbonyl sigma bonded coligands, has been synthesized. Compounds bearing nitrogen bonded coligands were found to be unstable in aqueous solution, while the others presented appropriate stabilities for the biologic assays and pursued for determination of IC50 values in ovarian (A2780) and breast (MCF7 and MDAMB231) human cancer cell lines. These studies were also carried out for the [5: HSA] and [6: HSA] adducts (HSA = human serum albumin) and a better performance was found for the first case. Spectroscopic, electrochemical studies by cyclic voltammetry and density functional theory calculations allowed us to get some understanding on the electronic flow directions within the molecules and to find a possible clue concerning the structural features of coligands that can activate bipyridyl ligands toward an increased cytotoxic effect. X-ray structure analysis of compound [Ru(eta(5)-C5H5)(bipy)(PPh3)][PF6] (7; bipy = bipyridine) showed crystallization on C2/c space group with two enantiomers of the [Ru(eta(5)-C5H5)(bipy)(PPh3)](+) cation complex in the racemic crystal packing. (C) 2015 Elsevier Inc All rights reserved.
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Electrocardiogram (ECG) biometrics are a relatively recent trend in biometric recognition, with at least 13 years of development in peer-reviewed literature. Most of the proposed biometric techniques perform classifi-cation on features extracted from either heartbeats or from ECG based transformed signals. The best representation is yet to be decided. This paper studies an alternative representation, a dissimilarity space, based on the pairwise dissimilarity between templates and subjects' signals. Additionally, this representation can make use of ECG signals sourced from multiple leads. Configurations of three leads will be tested and contrasted with single-lead experiments. Using the same k-NN classifier the results proved superior to those obtained through a similar algorithm which does not employ a dissimilarity representation. The best Authentication EER went as low as 1:53% for a database employing 503 subjects. However, the employment of extra leads did not prove itself advantageous.
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A new family of eight ruthenium(II)-cyclopentadienyl bipyridine derivatives, bearing nitrogen, sulfur, phosphorous and carbonyl sigma bonded coligands, has been synthesized. Compounds bearing nitrogen bonded coligands were found to be unstable in aqueous solution, while the others presented appropriate stabilities for the biologic assays and pursued for determination of IC50 values in ovarian (A2780) and breast (MCF7 and MDAMB231) human cancer cell lines. These studies were also carried out for the [5: HSA] and [6: HSA] adducts (HSA=human serum albumin) and a better performance was found for the first case. Spectroscopic, electrochemical studies by cyclic voltammetry and density functional theory calculations allowed us to get some understanding on the electronic flow directions within the molecules and to find a possible clue concerning the structural features of coligands that can activate bipyridyl ligands toward an increased cytotoxic effect. X-ray structure analysis of compound [Ru((5)-C5H5)(bipy)(PPh3)][PF6] (7; bipy=bipyridine) showed crystallization on C2/c space group with two enantiomers of the [Ru((5)-C5H5)(bipy)(PPh3)](+) cation complex in the racemic crystal packing.
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Os Lquidos Inicos (LIs) so sais orgnicos constitudos exclusivamente por ies e possuem pontos de fuso inferiores a 100C. As suas propriedades nicas e o facto de ser possvel ajustar as suas propriedades fsicas, qumicas e biolgicas, de acordo com o objetivo pretendido, tornam esta classe de compostos, um grande objeto de estudo de inmeros investigadores. Desde os incios da sua aplicao at atualidade, a investigao nesta rea expandiu o seu raio de ao, estando j descrito o seu potencial como agentes antimicrobianos e, mais recentemente, como compostos farmacuticos ativos. Atualmente muitas das suas aplicaes so baseadas nas suas propriedades biolgicas. Esta Tese teve como objetivo avaliar a influncia que os LIs podem exercer a nvel do crescimento bacteriano e estudar alternativas de combater a resistncia bacteriana. Todos os LIs utilizados neste trabalho tinham como anio o cido valprico, sendo utilizados caties orgnicos de amnio e de imidazlio. Foram utilizadas 4 bactrias e avaliou-se a atividade biolgica e a respetiva taxa de crescimento. O estudo da sua atividade biolgica foi feito atravs da determinao da Concentrao Mnima Inibitria (CMI) e a anlise das suas curvas de crescimentos na presena e ausncia de composto. Com este trabalho foi possvel verificar que dentro dos compostos em estudo, LIs derivados do valproato, o Valproato com o cetilperidnio [valp] [cetylpir] foi o que influenciou o crescimento de todas as bactrias estudadas. Este estudo demonstrou o potencial antibacteriano de alguns compostos, podendo desta forma vir a ser utilizados para fins farmacuticos
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RESUMO: Vrias intervenes psiquitricas e psicossociais tm demonstrado ser eficazes na reduo da depresso e da ansiedade em indivduos que sofreram um acidente coronrio agudo. A possiblidade de modificarem a evoluo da doena coronria e de reduzirem a mortalidade cardaca continua, no entanto, por comprovar. Este estudo teve como principal objectivo avaliar a efectividade de uma interveno de Psiquiatria de Ligao (PL) em doentes com cardiopatia isqumica aguda. Mtodos: um grupo inicial de 129 doentes consecutivos, internados por Enfarte Agudo do Miocrdio (EAM) ou Angina Instvel, numa unidade de cuidados intensivos foi avaliado com a Hospital Anxiety e Depression Scale (HADS). Os doentes que apresentaram uma pontuao 8 nas subescalas da Depresso ou da Ansiedade (n=72) foram aleatoriamente distribudos por grupo de interveno (GI) (n=37) e grupo de controlo (GC) (n=35). O GI foi sujeito a uma interveno de PL, realizada durante o perodo hospitalar, que se iniciou nos primeiros dias de internamento e consistiu em pelo menos 3 sesses individuais (incluindo avaliao psiquitrica, psicoterapia de suporte, interveno psicoeducativa e medicao, quando necessrio). A sesso pr-alta envolveu o cnjuge e abordou a modificao de comportamentos de risco, a adeso teraputica e o regresso ao trabalho. O GC recebeu os cuidados habituais da unidade de internamento. Todos os doentes completaram uma entrevista inicial para avaliao do estado cognitivo (Mini Mental State Examination MMSE), do ajustamento social (Social Problems Questionnaire SPQ) e de aspectos sociodemogrfi cos e clnicos. Os doentes foram reavaliados antes da alta, aos 45 dias, 3 e 6 meses com a HADS, o SPQ e ainda com o Nottingham Health Profi le (NHP) para avaliao da qualidade de vida. No follow-up de 6 meses foi colhida informao sobre sobrevivncia, nmero e durao de reinternamentos, nmero de dias de baixa e regresso ao trabalho. Resultados: na amostra de 129 doentes avaliados no incio do internamento, 20,9% apresentavam nveis de depresso 8 na subescala da Depresso (HADS), 53,5% nveis de ansiedade 8 na subescala da Ansiedade (HADS) e 9,3% perturbaes cognitivas (MMSE). A avaliao longitudinal desta amostra mostrou que os nveis de depresso, inicialmente baixos, aumentaram nos 45 dias aps o internamento, para depois diminurem at ao fi nal do follow-up. Os nveis de ansiedade, que eram inicialmente altos, aumentaram nos 45 dias seguintes e antiveram- se estveis, mas altos, at ao fi m do estudo. O GI apresentou uma pontuao mdia na subescala da depresso signifi cativamente inferior do GC no follow-up de 6 meses (5,84,1 no GI vs. 7,94,3 no GC, p=0,04). O nmero de doentes deprimidos foi signifi cativamente menor no GI nas avaliaes realizadas aos 3 meses (11 vs. 18 no GC, p=0,04) e aos 6 meses (12 vs. 18 no GC, p= 0,05). O mesmo aconteceu com o nmero de doentes ansiosos aos 3 meses (15 no GI vs. 23 no GC, p=0,01). As dimenses do NHP Isolamento social aos 45 dias e Reaco emocional aos 45 dias e aos 3 meses, bem como a qualidade de vida geral (NHP 2 parte) aos 3 meses, mostraram melhoria signifi cativa no grupo de interveno. Embora a interveno tenha reduzido o nvel mdio da ansiedade nas vrias avaliaes aps a alta, esta reduo no atingiu signifi cncia estatstica. A interveno realizada no teve impacto na mortalidade ou nas variveis relacionadas com a evoluo da doena cardaca no perodo do follow-up. Concluses: Os resultados do presente estudo mostram a alta prevalncia de depresso e de ansiedade aps um acidente coronrio agudo e a manuteno de nveis altos de ansiedade nos 6 meses seguintes. Os resultados comprovam tambm a efectividade de uma interveno em PL no tratamento da depresso e da ansiedade em doentes que sofreram um acidente coronrio agudo. Estes resultados apontam para a necessidade de desenvolvimento de programas de PL para este tipo de doentes, tanto no hospital geral como nos cuidados de sade primrios. Sugerem ainda a necessidade de desenvolvimento de investigao que permita estabelecer o impacto especfi co dos diversos tipos de interveno, assim como compreender os mecanismos subjacentes associao da depresso e da ansiedade com a doena coronria.----------ABSTRACT:Different types of psychiatric and psychochosocial interventions have proven effi cacy in decreasing anxiety and depression in coronary heart disease. There is, however, an ongoing discussion about the impact these interventions may have on the clinical outcome and on cardiac mortality. The main objective of the current study was to evaluate the effectiveness of a consultation liaison psychiatry (CL) intervention on a group of patients admitted with Myocardial Infarction or Unstable Angina, to a Coronary Care Unit. Methods: The study had a prospective, randomised, controlled design, with a 6-month follow-up. One hundred and twenty-nine consecutive patients were assessed during the first 48 hours of admission with the Hospital Anxiety and Depression Scale (HADS). Those with a score of 8 on the Depression or the Anxiety subscales (n=72) were randomly allocated to intervention (n=37) and usual care (n=35). The CL intervention, started during the fi rst days of admission, had a minimum of 3 (60 minutes) sessions, and included a psychiatric evaluation, supportive psychotherapy, a psychoeducational intervention, when necessary, psychotropic drugs. The last session, shortly before discharge, included the spouse and was focused on compliance, modifi cation of behavioral risk factors, and possible diffi culties upon returning to work. Cognitive status (Mini-Mental State Examination - MMSE), social adjustment (Social Problems Questionnaire - SPQ), and demographic and clinical characteristics were also assessed at baseline. Patients were reassessed before discharge, and at 45 days, 3 and 6 months after admission with HADS, SPQ, and with Nottingham Health Profile (NHP) for quality of life. Survival, number of readmissions and days of readmission, number of sickleave days and return to work were assessed at six months. Results: The initial sample of 129 patients, presented a 20.9% prevalence of depressive symptoms, 53.5% of anxiety symptoms, and 9.3% of cognitive disorders. The longitudinal evaluation of this sample showed that the initially low levels of depression were increased 45 days later, and slowlly decreased afterwards till the 6-month follow-up. Initially high anxiety levels, somewhat decreased before discharge, had increased 45 days later, and stayed stable and high till the end of the study. The intervention group showed a signifi cantly lower depression mean score at 6 months (5.84.1 vs. 7.94.3 in the controls, p=0.04). The number of patients considered depressed was lower in the intervention group at 3(11 vs. 18 controls, p=0.04) and 6 months (12vs. 18 controls, p=0,05). The number of anxious patients was also lower in the intervention.
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Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies.
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Nesta dissertao pretendeu-se estudar a viabilidade do uso de eletrodilise com membranas bipolares (BM) na recuperao de cido clordrico e de hidrxido de sdio a partir de um efluente industrial que contm 1.4 mol/L de cloreto de sdio. Estas membranas mostraram ser uma ferramenta eficiente para a produo de cidos e bases a partir do respetivo sal. Foi feita uma seleo de diferentes membranas bipolares (Neosepta, Fumatech e PCA) e aninicas (PC-SA e PC-ACID 60) na tentativa de encontrar a combinao mais adequada para o tratamento do efluente. Dependendo do critrio, o melhor arranjo de membranas o uso de PC-ACID 60 (membrana aninica), PC-SK (membrana catinica) e membranas bipolares do tipo Neosepta para maior pureza dos produtos; membranas bipolares Fumatech para maior eficincia de dessalinizao e membranas bipolares PCA para um maior grau de dessalinizao. Tecnologicamente foi possvel obter uma dessalinizao de 99.8% em quatro horas de funcionamento em modo batch com recirculao de todas as correntes. Independentemente da combinao usada recomendvel que o processo seja parado quando a densidade de corrente deixa de ser mxima, 781 A/m2. Assim possvel evitar o aumento de impurezas nos produtos, contra difuso, descida instantnea do pH e uma dessalinizao pouco eficiente. A nvel piloto o principal fornecedor de membranas e unidade de tratamento stack a marca alem PCA. Sendo assim realizaram-se ensaios de repetibilidade, contra difuso, avaliao econmica e upscaling utilizando as membranas bipolares PCA. A nvel econmico estudou-se o uso de dois tipos de unidades de tratamento; EDQ 380 e EDQ 1600, para diferentes nveis de dessalinizao (50, 75 e 80%). Tendo em conta a otimizao econmica, recomendvel uma dessalinizao mxima de 80%, uma vez que a eficincia de processo a este ponto de 40%. A aplicao do mtodo com a unidade EDQ 1600 para uma dessalinizao de 50% a mais vantajosa economicamente, com custos de 16 /m3 de efluente tratado ou 0,78 /kg Cl- removido. O nmero de unidades necessrias 4 posicionados em srie.
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Dissertao apresentada para cumprimento dos requisitos necessrios obteno do grau de Mestre em Desenvolvimento e Perturbaes da Linguagem na Criana, rea de especializao em Educao e Ensino da Lngua
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RESUMO: A presente dissertao para tese de doutoramento apresenta o desenvolvimento e a validao de um mtodo simples e original para o diagnstico de calcificaes vasculares em doentes em dilise, utilizando um score semiquantitativo criado por ns e obtido em RX simples da bacia e das mos, denominado score de calcifi cao vascular simples. Demonstramos que este score vascular simples preditor de risco cardiovascular nos doentes em dilise. O score de calcificao vascular simples associou-se ainda baixa densidade mineral ssea avaliada por dual energy X -ray absortiometry (DXA) no colo do fmur. Verifi camos igualmente que, em doentes em dilise, as calcifi caes coronrias quantifi cadas pelo score de Agatston e o score de calcifi cao vascular simples se associaram a um menor volume sseo avaliado em biopsias sseas. Estes trabalhos corroboram a hiptese da existncia de um elo de ligao entre a doena ssea e a doena vascular nos doentes em dilise, e um dos elementos que contribuem para este elo de ligao podem ser as calcificaes vasculares. Este score de calcificao vascular simples avalia calcifi caes em artrias de grande, mdio e pequeno calibre, e inclui os dois padres radiolgicos de calcificao: calcificao linear, associada calcifi cao da camada mdia da parede arterial, e calcificao irregular, associada calcifi cao da camada ntima arterial1. Nos diferentes trabalhos por ns publicados demonstramos que as calcificaes vasculares avaliadas por este mtodo simples e barato permitem a identificao de indivduos com elevado risco cardiovascular. Este score vascular associa -se a maior risco de mortalidade cardiovascular2, de mortalidade de causa global3, de internamentos cardiovasculares2, de doena ardiovascular2, de doena arterial perifrica2,4,de calcifi caes valvulares5 e de rigidez arterial3. As guidelines KDIGO (Kidney disease: improving global outcomes), publicadas em 2009,sugerem que os doentes renais crnicos nos estadios 3 a 5, com calcificaes vasculares e valvulares, devem ser considerados como apresentando o mais elevado risco cardiovascular6. A elevada mortalidade dos doentes renais crnicos no totalmente explicada pelos fatores de risco tradicionais7. A organizao KDIGO defende, desde 2006, a hiptese da existncia de um elo de ligao entre a doena ssea e a doena vascular8. Esta ligao pode ser explicada pelas alteraes do metabolismo mineral e sseo e pela sua interao com as calcificaes vasculares. Verificamos, nos nossos trabalhos, uma associao entre calcifi caes vasculares e doena ssea. O baixo volume sseo diagnosticado por anlise histomorfomtrica de biopsias sseas foi preditor de maior risco de calcificaes vasculares avaliadas pelo score de calcifi cao vascular simples (dados apresentados nesta dissertao, no captulo 6) e pelo score coronrio de Agatston num grupo de doentes em dilise9. A contribuio original deste artigo9 foi considerada merecedora de um editorial feito pelo Dr. Grard London10, investigador lder na rea da calcificao vascular dos doentes renais crnicos e actual Presidente da EDTA (European Dialysis and Transplantation Association). Fomos tambm os primeiros a descrever uma associao independente e inversa entre a densidade mineral avaliada no colo do fmur por DXA (dual energy X -ray absortiometry) com calcificaes vasculares avaliadas pelo score de calcificao vascular simples, com rigidez arterial avaliada por velocidade de onda de pulsocarotidofemoral e com doena arterial perifrica diagnosticada por critrios clnicos11. Fomos igualmente os primeiros a mostrar uma correlao signifi cativa entre a densidade mineral ssea avaliada por DXA no colo do fmur, mas no na coluna lombar, com a espessura cortical avaliada por anlise histomorfomtrica em biopsia ssea12. O nosso estudo atribui pela primeira vez DXA um papel no diagnstico de porosidade cortical nos doentes em dilise. A utilidade da avaliao diferencial da densidade mineral ssea cortical e trabecular necessita ainda de ser confirmada em estudos prospectivos. Este achado inovador do nosso estudo foi mencionado pela ERBP (European Renal Best Practice) no comentrio feito posio da KDIGO que considera ser reduzida a utilidade da densidade mineral ssea nos doentes em dilise13. Dois dos trabalhos includos nesta dissertao foram referenciados nas guidelines KDIGO 2009 para avaliar a prevalncia das calcificaes vasculares (KDIGO 2009: Tabela suplementar 10, Fig. 3.6) e para validar a associao entre calcificaes vasculares e mortalidade cardiovascular (KDIGO 2009: Tabela suplementar 12, Fig. 3.7)6. A incluso destes nossos dois estudos nas referncias destas guidelines, que utilizaram o exigente sistema GRADE (Grades of recommendation, assessment, development, and evaluation) na classificao e seleco dos estudos, valida o interesse cientfico dos nossos trabalhos. O diagnstico de calcificaes vasculares tem um interesse prtico para os doentes renais crnicos. A presena de calcifi caes vasculares um sinal de alerta para a existncia de um elevado risco cardiovascular, e esta informao pode ser utilizada para modificar a teraputica nestes doentes6. Diferentes mtodos podem ser usados para diagnosticar calcificaes vasculares nos doentes em dilise14,15. O score de calcificao vascular simples tem a vantagem da simplicidade e de poder ser facilmente interpretado pelo nefrologista, sem necessidade de um radiologista. A reprodutibilidade deste score j foi demonstrada por diferentes grupos em estudos nacionais e internacionais16-24. Nestes estudos foi demonstrado que as calcifi caes vasculares avaliadas pelo mtodo criado por ns so preditoras de maior risco de eventos cardiovasculares16, de amputaes dos membros inferiores17, de velocidade de onda de pulso18,19, de calcificaes corneanas e conjuntivais20 e de calcifi caes coronrias21. Tambm foi demonstrada uma associao inversa entre o score de calcificao vascular simples com os nveis sricos de PTH21, com os nveis de 25(OH)vitamina D 22,23 e com os nveis de fetuna A19,24. Todos estes estudos, realizados por diferentes grupos, que utilizaram o score de calcificao vascular simples na sua metodologia, comprovam a facilidade de utilizao deste score e a concordncia de resultados atestam a sua reprodutibilidade e a utilidade na avaliao dos doentes renais crnicos. ---------------------------ABSTRACT: This thesis presents the development and validation of a simple and original method to identify vascular calcifications in dialysis patients, using a semi -quantitative score that we have created and that is obtained in plain X -ray of pelvis and hands. This score was named in different publications as simple vascular calcifi cation score. We have demonstrated that this score is a predictor of higher cardiovascular risk in dialysis patients. The simple vascular calcification score was also associated with lower mineral bone density evaluated by DXA in femoral neck. In hemodialysis patients coronary calcifications evaluated by the coronary Agatston score and by the simple vascular calcification score were associated with lower bone volume analysed in bone biopsies. These studies corroborate the hypothesis of the existence of a link between bone disease and vascular disease in dialysis patients and one of the elements of this link may be vascular calcifications. This simple vascular calcification score identifi es calcifications in large, medium and small calibre arteries and includes the two radiological patterns of arterial calcifi cation: linear calcification which has been associated with the calcifi cation of the media layer of the arterial wall and irregular and patchy calcification which has been associated with the calcifi cation of the intima layer of the arterial wall1. In the several studies that we have published we have demonstrated that vascular calcifications evaluated by this simple and inexpensive method allow the identification of patients with high cardiovascular risk. This simple vascular calcification score is an independent predictor of cardiovascular mortality2, all -cause mortality3, cardiovascular hospitalizations2, cardiovascular disease2, peripheral artery disease2,4, valvular calcifi cations5 and arterial stiffness3.KDIGO (Kidney Disease: Improving Global Outcomes) guidelines published in 2009 suggest that chronic kidney disease patients in stages 3 to 5, with vascular and valvular calcifications should be considered to be at the highest cardiovascular risk6. The high mortality of chronic kidney disease patients is not completely explained by the traditional risk factors7 and KDIGO group supports, since 2006, the hypothesis of the existence of a link between bone disease and vascular disease8.This link may be explained by the alterations of the bone and mineral metabolism and their interaction with development and progression of vascular calcifications. We have also verifi ed in our studies the existence of an association between vascular calcifications and bone disease. Low bone volume diagnosed by histomorphometric analysis of bone biopsies, in a group of dialysis patients, was independently associated with the simple vascular calcification score (data presented in this thesis,chapter 6) and with coronary calcifications evaluated by the Agatston score9. The original contribution of this article published in CJASN9 deserved a commentary in an Editorial written by Prof. Grard London10 leader investigator in this area and current EDTA (European Dialysis and Transplantation Association) President. We were also the fi rst group to describe an independent and inverse association between bone mineral density evaluated in the femoral neck by DXA (dual energy X -ray absortiometry) with vascular calcifications evaluated by the simple vascular calcification score, with arterial stiffness evaluated by carotid-femoral pulse wave velocity and with peripheral artery disease diagnosed by clinical criteria11. We were also the first group to demonstrate a significant correlation between bone mineral density evaluated by DXA in femoral neck but not in lumbar spine, with cortical thickness evaluated by histomorphometric analysis of bone biopsy12. Our study has attributed to DXA, for the first time, a role in the diagnosis of cortical porosity in dialysis patients. The clinical utility of the differential evaluation of bone mineral density in cortical or trabecular bone needs, however, to be confi rmed in prospective studies. This original fi nding of our study was mentioned by ERBP (European Renal Best Practice) commenting the KDIGO position in relation with the reduced utility of bone mineral density evaluation in dialysis patients13. Two of the studies included in this thesis have been integrated in a group of studies selected as references by the KDIGO guidelines published in 2009 to evaluate the prevalence of vascular calcifications in CKD patients (KDIGO 2009: Supplementary Table 10, Fig. 3.6) and to corroborate the association between vascular calcifications and cardiovascular mortality (KDIGO 2009: Supplementary Table 12, Fig. 3.7)6. The inclusion of both studies as references in the KDIGO guidelines that have used the exigent GRADE system (Grades of Recommendation, Assessment, Development, and Evaluation) in the classifi cation and selection of studies, validates the scientifi c value of our studies. The diagnosis of vascular calcifi cations has a practical interest for chronic kidney disease patients. The presence of vascular calcifications is an alert sign to the existence of a high cardiovascular risk and this information may be used to modify the treatment of these patients6. Different methods may be used to detect the presence of vascular calcifications in dialysis patients14,15. The simple vascular calcifi cation score has the advantage of being simple, inexpensive and easily evaluated by the Nephrologist without the need for a Radiologist interpretation. The reproducibility of this method has already been demonstrated by other groups in national and international studies16 -24. It was demonstrated in those studies that vascular calcifi cations evaluated by the method created by us, predict higher risk of cardiovascular events16, higher risk of lower limbs amputations17, higher pulse wave velocity18,19, corneal and conjuntival calcifi cations 20 and coronary calcifi cations21. A negative association between the simple vascular calcification score and PTH levels21, 25(OH) vitamin D levels22,23 and Fetuin A levels19,24 has also been demonstrated. All these studies performed by different groups that have used the simple vascular calcifi cation score in their methods demonstrate that this score is simple, useful and reproducible in the evaluation of chronic kidney disease patients simple, useful and reproducible in the evaluation of chronic kidney disease patients.
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Existing gamication services have features that preclude their use by e-learning tools. Odin is a gamication service that mimics the API of state-of-the-art services without these limitations. This paper describes Odin, its role in an e-learning system architecture requiring gamication, and details its implementation. The validation of Odin involved the creation of a small e-learning game, integrated in a Learning Management System (LMS) using the Learning Tools Interoperability (LTI) specication.
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Post-MAPS is a web platform that collects gastroenterological exam data from several european hospital centers, to be used in future clinical studies and was developed in partnership with experts from the gastroenterological area and information technology (IT) technicians. However, although functional, this platform has some issues that are crucial for its functioning, and can render user interaction unpleasant and exhaustive. Accordingly, we proposed the development of a new web platform, in which we aimed for an improvement in terms of usability, data uni cation and interoperability. Therefore, it was necessary to identify and study different ways of acquiring clinical data and review some of the existing clinical databases in order to understand how they work and what type of data they store, as well as their impact and contribution to clinical knowledge. Closely linked to the data model is the ability to share data with other systems, so, we also studied the concept of interoperability and analyzed some of the most widely used international standards, such as DICOM, HL7 and openEHR. As one of the primary objectives of this project was to achieve a better level of usability, practices related to Human Computer-Interaction, such as requirement analysis, creation of conceptual models, prototyping, and evaluation were also studied. Before we began the development, we conducted an analysis of the previous platform, from a functional point of view, which allowed us to gather not only a list of architectural and interface issues, but also a list of improvement opportunities. It was also performed a small preliminary study in order to evaluate the platform's usability, where we were able to realize that perceived usability is different between users, and that, in some aspects, varies according to their location, age and years of experience. Based on the information gathered during the platform's analysis and in the conclusions of the preliminary study, a new platform was developed, prepared for all potential users, from the inexperienced to the most comfortable with technology. It presents major improvements in terms of usability, also providing several new features that simplify the users' work, improving their interaction with the system, making their experience more enjoyable.
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Introduction: C-reactive protein (CRP) and Bedside Index for Severity in Acute Pancreatitis (BISAP) have been used in early risk assessment of patients with AP. Objectives: We evaluated prognostic accuracy of CRP at 24 hours after hospital admission (CRP24) for in-hospital mortality (IM) in AP individually and with BISAP. Materials and Methods: This retrospective cohort study included 134 patients with AP from a Portuguese hospital in 2009---2010. Prognostic accuracy assessment used area under receiver---operating characteristic curve (AUC), continuous net reclassication improvement (NRI), and integrated discrimination improvement (IDI). Results: Thirteen percent of patients had severe AP, 26% developed pancreatic necrosis, and 7% died during index hospital stay. AUCs for CRP24 and BISAP individually were 0.80 (95% condence interval (CI) 0.65---0.95) and 0.77 (95% CI 0.59---0.95), respectively. No patients with CRP24 <60 mg/l died (P = 0.027; negative predictive value 100% (95% CI 92.3---100%)). AUC for BISAP plus CRP24 was 0.81 (95% CI 0.65---0.97). Change in NRI nonevents (42.4%; 95% CI, 24.9---59.9%) resulted in positive overall NRI (31.3%; 95% CI, 36.4% to 98.9%), but IDI nonevents was negligible (0.004; 95% CI, 0.007 to 0.014). Conclusions: CRP24 revealed good prognostic accuracy for IM in AP; its main role may be the selection of lowest risk patients.
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Dissertation presented to obtain the Ph.D degree in Biochemistry
