Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

2017

Synthesis, spectroscopic characterization and biological evaluation of unsymmetrical aminosquarylium cyanine dyes

Authors
Friaes, S; Silva, AM; Boto, RE; Ferreira, D; Fernandes, JR; Souto, EB; Almeida, P; Vieira Ferreira, LFV; Reis, LV;

Publication
BIOORGANIC & MEDICINAL CHEMISTRY

Abstract
New unsymmetrical aminosquarylium cyanine dyes were synthesized and their potential as photosensitizers evaluated. New dyes, derived from benzothiazole and quinoline, were prepared by nucleophilic substitution of the corresponding O-methylated, the key intermediate that was obtained by methylation with CF3SO3CH3 of the related zwitterionic unsymmetrical dye, with ammonia and methylamine, respectively. All three news dyes herein described displayed intense and narrow bands in the Vis/NIR region (693-714 nm) and their singlet oxygen formation quantum yields ranged from 0.03 to 0.05. In vitro toxicity, in Caco-2 and HepG2 cells, indicated that dark toxicity was absent for concentrations up to 5 mu M (for the less active dye) or up to 1 mu M (for the two more active dyes). The three dyes present potential as photosensitizers, differing in irradiation conditions and period of incubation in the presence of irradiated dye. The less active dye needs a longer irradiation period to exhibit phototoxicity which is only evident after longer period of contact with cells (24 h). However, the remaining two more active dyes produce higher phototoxicity, even at shorter incubation periods (1 h), with shorter irradiation time (7 min). Although in different extents, these dyes show promising in vitro results as photosensitizers.

2017

Preface

Authors
de Carvalho, CV; Coelho, A; Escudeiro, P;

Publication
Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST

Abstract

2017

A Modular Traffic Sampling Architecture: Bringing Versatility and Efficiency to Massive Traffic Analysis

Authors
Silva, JMC; Carvalho, P; Lima, SR;

Publication
J. Netw. Syst. Manag.

Abstract
The massive traffic volumes and heterogeneity of services in today’s networks urge for flexible, yet simple measurement solutions to assist network management tasks, without impairing network performance. To turn treatable tasks requiring traffic analysis, sampling the traffic has become mandatory, triggering substantial research in the area. Despite that, there is still a lack of an encompassing solution able to support the flexible deployment of sampling techniques in production networks, adequate to diverse traffic scenarios and measurement activities. In this context, this article proposes a modular traffic sampling architecture able to foster the flexible design and deployment of efficient measurement strategies. The architecture is composed of three layers—management plane, control plane and data plane—covering key components to achieve versatile and lightweight measurements in diverse traffic scenarios and measurement activities. Each component of the architecture is described considering the different strategies, technologies and protocols that compose the several stages of a measurement process. Following the proposed architecture, a sampling framework prototype has been developed, providing a fair environment to assess and compare sampling techniques under distinct measurement scenarios, evaluating their performance in balancing computational burden and accuracy. The results have demonstrated the relevance and applicability of the proposed architecture, revealing that a modular and configurable approach to sampling is a step forward for improving sampling scope and efficiency. © 2017, Springer Science+Business Media New York.

2017

A Comparative Study of Electronic Stethoscopes for Cardiac Auscultation

Authors
Pinto, C; Pereira, D; Ferreira Coimbra, J; Portugues, J; Gama, V; Coimbra, M;

Publication
2017 39TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)

Abstract
There are several electronic stethoscopes available on the market today, with a very high potential for healthcare namely telemedicine, assisted decision and education. However, there are no recent comparatives studies published about the recording quality of auscultation sounds. In this study we aim to: a) define a ranking, according to experts opinion of 6 of the most relevant electronic stethoscopes on the market today; b) verify if there are any relations between a stethoscope's performance and the type of pathology present; c) analyze if some pathologies are more easily identified than others when using electronic auscultation. Our methodology consisted in creating two study groups: the first group included 18 cardiologists and cardiology house officers, acting as the gold standard of this work. The second included 30 medical students. Using a database of heart sounds recorded in real hospital environments, we applied questionnaires to observers from each group. The first group listened to 60 cardiac auscultations recorded by the 6 stethoscopes, and each one was asked to identify the pathological sound present: aortic stenosis, mitral regurgitation or normal. The second group was asked to choose, between two auscultation recordings, using as criteria the best sound quality for the identification of pathological sounds. Results include a total of 1080 evaluations, in which 72% of cases were correctly diagnosed. A detailed breakdown of these results is presented in this paper. As conclusions, results showed that the impact of the differences between stethoscopes is very small, given that we did not find statistically significant differences between all pairs of stethoscopes. Normal sounds showed to be easier to identify than pathological sounds, but we did not find differences between stethoscopes in this identification.

2017

Behavioural types: From theory to tools english

Authors
Gay, S; Ravara, A;

Publication
Behavioural Types: from Theory to Tools English

Abstract
Behavioural type systems in programming languages support the specification and verification of properties of programs beyond the traditional use of type systems to describe data processing. A major example of such a property is correctness of communication in concurrent and distributed systems, motivated by the importance of structured communication in modern software. Behavioural Types: from Theory to Tools presents programming languages and software tools produced by members of COST Action IC1201: Behavioural Types for Reliable Large-Scale Software Systems, a European research network that was funded from October 2012 to October 2016. As a survey of the most recent developments in the application of behavioural type systems, it is a valuable reference for researchers in the field, as well as an introduction to the area for graduate students and software developers.

2017

A multi-perspective theoretical analysis to web accessibility

Authors
Peixoto, C; Branco, F; Martins, J; Gonçalves, R;

Publication
Research Paradigms and Contemporary Perspectives on Human-Technology Interaction

Abstract
Accessibility has become increasingly important in information technology, particularly due to legislation pressure to make affordable public services to all. Being end-users and software companies those who have direct contact with accessibility problems, other stakeholders are committed to defining methods and change mentalities in Web accessibility implementation. In addition to a conceptual definition, this chapter presents entities views with responsibilities in the area, taking into account their work done in the past and the prospects for future. The understanding of the interaction between all these perspectives will help to realize the way it will go, which carries with it great challenges and opportunities, widely explored in this work.

  • 1855
  • 4141