Effect of superabsorbent polymers (SAP) on fresh state mortars with ground granulated blast-furnace slag (GGBS)

Although cementitious materials are the main construction materials and worldwide produced, there is still a major concern about their sustainability and durability, especially in terms of conserving resources, reducing wastes, and decreasing the environmental impacts of repair and replacement. In general, cementitious materials are very susceptible to cracking provoked by autogenous shrinkage due to their associated self-desiccation process. The problem is even more critical in concrete with blended cements, including Portland cement with ground granulated blast-furnace slag (GGBS). The current paper evaluates efficiency of superabsorbent polymers (SAP) as internal curing agents; shrinkage reduction in mortars with different levels of cement replacement by GGBS (0, 25, 50, and 75%) is presented. The study is focused on three types of SAPs with different water absorption/desorption capacities (SAP I: 10 g/g, SAP II: 25–30 g/g, and SAP III: 35 g/g in cement paste solution). Tests of consistency, density, air content of fresh mortar, setting times, and autogenous shrinkage are analysed. The results showed that mortars with SAP can significantly reduce autogenous shrinkage for any studied GGBS content in comparison with the reference mortar. The reduction of autogenous shrinkage by SAP may decrease the cracking susceptibility and hence increase the sustainability level of the material for more durable constructions

Fatores preditores de resposta clínica em doentes com AVC isquémico submetidos a fibrinólise endovenosa

Trabalho final de mestrado integrado em Medicina área científica de neurologia, apresentado á Faculdade de Medicina da Universidade de CoimbraIntrodução Em Portugal, o AVC constitui a primeira causa de morte e uma das principais causas de incapacidade no adulto, sendo o alteplase (activador recombinante do plasminogénio tecidular – rt-PA) a única terapia médica aprovada. Vários estudos identificam fatores de risco, modificáveis e não modificáveis, como possíveis preditores de resposta clínica nestes doentes. Este trabalho tem como principal objetivo a identificação de variáveis clínicas, laboratoriais e imagiológicas determinantes do prognóstico funcional em doentes com AVC isquémico submetidos a fibrinólise endovenosa. Métodos Foram estudados ambiespetivamente os doentes consecutivamente internados na UAVC, entre 1 de Abril de 2010 a 30 de Abril de 2012, com o diagnóstico inicial de AVC isquémico, submetidos a fibrinólise endovenosa e para os quais foi possível recolher o estado funcional aos 3 meses. Os dados clínicos, laboratoriais e imagiológicos foram recolhidos por consulta de instrumento de registo específico da UAVC dos CHUC-HUC. O diagnóstico final foi confirmado por consulta de carta de alta. O status funcional do doente foi avaliado aos 3 meses utilizando a escala de mRS (modified Rankin Scale). Foram considerados dois grupos distintos: um designado de “bom outcome”, para valores de mRS ≤2; e um outro designado de “mau outcome”, contemplando os doentes com mRS >2. Resultados O estudo incluiu um total de 173 doentes com diagnóstico confirmado de AVC isquémico e submetidos a fibrinólise endovenosa. Em 34% documentou-se um bom outcome aos 3 meses, enquanto 66% tiveram um mau prognóstico funcional. Na análise univariada verificou-se haver uma relação estatisticamente significativa entre o prognóstico aos três meses de evolução e as variáveis: tabagismo; medicação crónica com anticoagulantes, IECAs, ARAs e ADO; NIHSS total e item 2; leucócitos; TAS e oclusão de artéria de grande calibre. Na análise multivariada, apenas mantiveram independência como fatores preditores de prognóstico o tabagismo, a toma de ARAs, o valor de NIHSS total e a oclusão de artéria de grande calibre. Conclusão Os resultados deste estudo sugerem a medicação crónica com ARAs, a avaliação inicial pelo NIHSS (valor total) e o local de oclusão arterial como fatores preditores de resposta clínica à fibrinólise endovenosa, como terapia aguda do AVC isquémico.Background Stroke is in Portugal the first cause of death and one of the most important causes of disability in the adults, being alteplase (recombinant tissue plasminogen activator – rt-PA) the only medical treatment approved. Many studies already identified risk factors, modifiable or not, as possible predictors of clinical response on those patients. The aim of present work is identifying clinical, laboratorial and imagiological risk factors whose determine the functional prognostic in patients with acute ischemic stroke and treated with intravenous fibrinolysis. Methods All the patients admitted at the Stroke Unity, between first of April 2010 to 30th of April 2012, with the initial diagnose of acute ischemic stroke and treated with intravenous fibrinolysis and for those was possible to know the functional prognosis after three months were ambiespectively studied. Clinical, laboratorial and imagiological data were collected by accessing specific register instrumentation of Coimbra’s University Hospital’s Stroke Unity. Final diagnosis was confirmed by checking note of discharge. Functional status of patients was determined by using mRS (modified Rankin Scale) at the three months. Two distinct groups were considered: one of those named “good outcome”, including all the patients with mRS ≤2; and one another named “bad outcome”, including all the patients with mRS >2. Results This study included a total of 173 patients with confirmed diagnosis of ischemic stroke and treated with intravenous fibrinolysis. 34% of them had a good outcome at three months, while 66% had a worst functional prognosis at the same time. In univariate analysis there was a statistically significant relationship between the three months’ prognosis and: tobacco; chronic medication with anticoagulants, ACE inhibitors, ARBs and oral antidiabetics; total score and item 2 of NIHSS; leukocytes; SBP and occlusion of large artery. In multivariate analysis, only tobacco, ARBs, total value of NIHSS and occlusion of big artery, maintained the status of independent prognostic factors. Conclusions The results of this study suggest chronic medication with ARBs, initial neurological evaluation by using NIHSS (total score) and the local where the arterial occlusion occurs, as clinical prognostic factors by using intravenous fibrinolytic therapy in patients with acute ischemic stroke

Influencia del paradigma tecnológico en la organización de la información

A technological paradigm supports the so called information society. Starting with an approximation to the informational reality, the presence of such paradigm in the development of the theory and practice of Information Science is exposed. A characterization is made on the influence of such paradigm at a sub disciplinary level in the organization of the information. The meaning of the social and cognitive dimension in the conception of the Web semantics is emphasized, in the present technological context