Water sorption into poly[(2-hydroxyethyl methacrylate)-co-(1-vinyl-2-pyrrolidone]at 310 K

Poly(2-hydroxyethyl methacrylate) and copolymers of 2-hydroxyethyl methacrylate (HEMA) and 1-vinyl-2-pyrrolidone (VP) in the form of cylindrical samples (approximate to8mm x 20mm) have been prepared and the sorption of water into these cylinders has been studied by the mass-uptake methods and by magnetic-resonance imaging. The equilibrium water contents for the cylinders were found to vary systematically with the copolymer composition. Diffusion of water into the cylinders was found to follow Fickian behaviour for cylinders with high HEMA contents, with the diffusion coefficients obtained from mass-uptake studies dependent on the copolymer composition, varying from 1.7 x 10(-11) m(2) s(-1) for poly(HEMA) to 2.0 x 10(-11) m(2) s(-1) for poly(HEMA-co-VP) with a composition of 1:1. However, NMR-imaging studies showed that, while the profiles of the water diffusion fronts for cylinders with high HEMA contents were Fickian, that for the 1:1 copolymer was not and indicated that the mechanism was Case III. The polymers which were rich in VP were characterized by a water-sorption process which follows Case-III behaviour. (C) 2003 Society of Chemical Industry.

Resolution enhancement by subtraction of confocal signals taken at different pinhole sizes

Subtractive imaging in confocal fluorescence light microscopy is based on the subtraction of a suitably weighted widefield image from a confocal image. An approximation to a widefield image can be obtained by detection with an opened confocal pinhole. The subtraction of images enhances the resolution in-plane as well as along the optic axis. Due to the linearity of the approach, the effect of subtractive imaging in Fourier-space corresponds to a reduction of low spatial frequency contributions leading to a relative enhancement of the high frequencies. Along the direction of the optic axis this also results in an improved sectioning. Image processing can achieve a similar effect. However, a 3D volume dataset must be acquired and processed, yielding a result essentially identical to subtractive imaging but superior in signal-to-noise ratio. The latter can be increased further with the technique of weighted averaging in Fourier-space. A comparison of 2D and 3D experimental data analysed with subtractive imaging, the equivalent Fourier-space processing of the confocal data only, and Fourier-space weighted averaging is presented. (C) 2003 Elsevier Ltd. All rights reserved.

Indicadores de Ci��ncia, Tecnologia & Inova����o : an��lise da produ����o cient��fica e tecnol��gica da ��rea de conhecimento em Engenharia Civil na Base de Dados da Web of Science

Esta disserta����o trata da an��lise da produ����o cient��fica e tecnol��gica internacional e brasileira na ��rea de conhecimento Engenharia Civil, por meio de indicadores bibliom��tricos. A ��rea Engenharia Civil foi escolhida em raz��o da sua relev��ncia para o desenvolvimento econ��mico do pa��s. No entanto, em termos absolutos e relativos, est�� entre os setores tecnologicamente mais atrasados da economia. A bibliometria �� uma disciplina com alcance multidisciplinar que estuda o uso e os aspectos quantitativos da produ����o cient��fica registrada. Os indicadores de produ����o cient��fica s��o objeto de an��lise de v��rias ��reas do conhecimento, tanto para o planejamento e a execu����o de pol��ticas p��blicas de v��rios setores quanto para maior conhecimento da comunidade cient��fica sobre o sistema em que est�� inserida. A metodologia utilizada para a elabora����o deste estudo descritivo de car��ter explorat��rio foi a an��lise documental e bibliom��trica, baseada em dados das publica����es cient��ficas, no per��odo de 1970 a 2012, e tecnol��gicas, no per��odo de 2001 a 2012, da ��rea Engenharia Civil, indexadas nas bases de dados Science Citattion Index Expanded (SCI); Social Science Citation Index (SSCI); Conference Proceedings Citation Index (CPCI) e da Derwent Innovations Index (DII), que comp��em a base de dados multidisciplinar da Web of Sicence (WoS). As informa����es foram qualificadas e quantificadas com o aux��lio do software bibliom��trico VantagePoint��. Os resultados obtidos confirmaram o baixo n��mero de publica����es cient��ficas e tecnol��gicas na ��rea de conhecimento Engenharia Civil de autores filiados a institui����es de ensino e pesquisa brasileiras quando comparados aos dos pa��ses industrializados. Existe um conjunto de fortes condicionantes que ultrapassam o poder de decis��o e de influ��ncia da academia, dificultando e limitando a dissemina����o das pesquisas e patentes brasileiras relacionadas a fatores de car��ter sist��mico e cultural. A possibilidade de an��lise de indicadores de produ����o cient��fica e tecnol��gica na Engenharia Civil contribui para criar pol��ticas que, se utilizadas por ag��ncias de fomento, podem subsidiar investimentos mais fundamentados por parte dos governos e da iniciativa privada, a exemplo do que �� feito por outros setores industriais.

Thermal skin reference values in healthy late pregnancy

Digital thermal imaging has been employed in medicine for over 50 years. However, its use has been focused on vascular, musculoskeletal and neurological conditions, while other potential applications,such as obstetrics, have been much less explored. This paper presents a study conducted during 2011 at the Hospital of Braga on a group of healthy pregnant women in the last third of gestation. The analysis focused on characterizing typical pregnant women steady temperature profiles in specific defined regions of interest (ROI), and determining if the thermal symmetry values for late pregnant healthy women are in line with the values for non-pregnant healthy women. A temperature distribution pattern was found in the defined ROI. The obtained thermal symmetry value had a maximum of 0.370.2 1C, and there was no evidence for the influence of age (p40.05) in the observed group. The influence of the BMI requires further investigation since one ROI (P2 right) presented a p��0.059, close to the threshold of statistical evidence in the influence of BMI. The study group presented symmetry values in line with non-pregnant reference values, but the profiles in temperature distribution are different. Assumptions can therefore now be used with higher confidence when assessing abnormalities in specific pathologic states during pregnancy using the defined ROI. This work represents a first contribution towards establishing guidelines for future research in this specific field of study.

Color Models and Illumination Changes

Color model representation allows characterizing in a quantitative manner, any defined color spectrum of visible light, i.e. with a wavelength between 400nm and 700nm. To accomplish that, each model, or color space, is associated with a function that allows mapping the spectral power distribution of the visible electromagnetic radiation, in a space defined by a set of discrete values that quantify the color components composing the model. Some color spaces are sensitive to changes in lighting conditions. Others assure the preservation of certain chromatic features, remaining immune to these changes. Therefore, it becomes necessary to identify the strengths and weaknesses of each model in order to justify the adoption of color spaces in image processing and analysis techniques. This chapter will address the topic of digital imaging, main standards and formats. Next we will set the mathematical model of the image acquisition sensor response, which enables assessment of the various color spaces, with the aim of determining their invariance to illumination changes.

Kidney targeting and puncturing during percutaneous nephrolithotomy: recent advances and future perspectives

Background and Purpose: Precise needle puncture of the kidney is a challenging and essential step for successful percutaneous nephrolithotomy (PCNL). Many devices and surgical techniques have been developed to easily achieve suitable renal access. This article presents a critical review to address the methodologies and techniques for conducting kidney targeting and the puncture step during PCNL. Based on this study, research paths are also provided for PCNL procedure improvement. Methods: Most relevant works concerning PCNL puncture were identified by a search of Medline/PubMed, ISI Web of Science, and Scopus databases from 2007 to December 2012. Two authors independently reviewed the studies. Results: A total of 911 abstracts and 346 full-text articles were assessed and discussed; 52 were included in this review as a summary of the main contributions to kidney targeting and puncturing. Conclusions: Multiple paths and technologic advances have been proposed in the field of urology and minimally invasive surgery to improve PCNL puncture. The most relevant contributions, however, have been provided by the applicationofmedical imaging guidance, newsurgical tools,motion tracking systems, robotics, andimage processing and computer graphics. Despite the multiple research paths for PCNL puncture guidance, no widely acceptable solution has yet been reached, and it remains an active and challenging research field. Future developments should focus on real-time methods, robust and accurate algorithms, and radiation free imaging techniques

��Corruption�� and social and economic criminal law: criminology, criminal policy, political science and law&economics - a new idea about criminal liability of legal entities

Abstract: If we think there is a significant number of legal offshore in the globalized world, then there is not even a global consensus about what ��corruption�� is. The ��illegal corruption�� in a country may be legal in another. Moreover, the great global corruption is above the law or above democratic States. And not all democratic States are ��Rule of Law��. Therefore, the solution is global earlier in time and space law, democratic, free and true law. While the human being does not reach a consensus of what ��corruption�� really is, the discussion will not go further than a caricature. One of the other problems about ��corruption�� is that it is very difficult to establish the imputation of crimes, including ��corruption�� (v.g. Portugal) on some ��companies��, corporations. We have a juridical problem in the composition of the art. 11. of the Portuguese Penal Code.

La Traductologie, Science Auxiliare du Droit

Revista Lus��fona de L��nguas, Culturas e Tradu����o

Albert-L��szl�� Barab��si, Linked ��� The New Science of Networks, Perseus, Cambridge, 2002. Duncan J. Watts, Six Degrees ��� The Science of a Connected Age, William Heinemann, Londres, 2003.

Com a cria����o da teoria das redes, assistiu-se nos ��ltimos anos a uma revolu����o cient��fica de car��cter interdisciplinar N��o �� uma teoria inteiramente nova, tendo sido precedida pela cria����o por P. Erdvos, nos anos sessenta, da teoria dos grafos aleat��rios. Esta ��ltima �� uma teoria puramente matem��tica, donde termos escrito ���grafo��� em lugar de ���rede���. Apenas recentemente podemos falar de uma efectiva teoria das redes reais, e isso devido ao abandono de algumas das ideias essenciais avan��adas por Erdvos, em especial a ideia de partir de um conjunto previamente dado de n��s, os quais de seguida v��o sendo conectados aleatoriamente com probabilidade p. Este quadro geral come��ou a ser modificado pelo chamado modelo dos ���mundo-pequenos��� proposto em 1998 por Duncan Watts e Steve Strogatz, modifica����o que se tornou ainda mais radical quando, em 1999, Albert Barab��si e colaboradores propuseram um modelo no qual os n��s v��o progressivamente nascendo e conectados por uma fun����o de prefer��ncia: um n�� conecta-se em propor����o ��s liga����es que os outros n��s j�� possuem, pelo que quantas mais liga����es um n�� possui maior a probabilidade de receber ulteriores liga����es.

Fluorescence Microscopy Imaging Denoising with Log-Euclidean Priors and Photobleaching Compensation

Fluorescent protein microscopy imaging is nowadays one of the most important tools in biomedical research. However, the resulting images present a low signal to noise ratio and a time intensity decay due to the photobleaching effect. This phenomenon is a consequence of the decreasing on the radiation emission efficiency of the tagging protein. This occurs because the fluorophore permanently loses its ability to fluoresce, due to photochemical reactions induced by the incident light. The Poisson multiplicative noise that corrupts these images, in addition with its quality degradation due to photobleaching, make long time biological observation processes very difficult. In this paper a denoising algorithm for Poisson data, where the photobleaching effect is explicitly taken into account, is described. The algorithm is designed in a Bayesian framework where the data fidelity term models the Poisson noise generation process as well as the exponential intensity decay caused by the photobleaching. The prior term is conceived with Gibbs priors and log-Euclidean potential functions, suitable to cope with the positivity constrained nature of the parameters to be estimated. Monte Carlo tests with synthetic data are presented to characterize the performance of the algorithm. One example with real data is included to illustrate its application.

Radiological imaging in digital systems: the effect of exposure parameters in diagnostic quality and patient dose

Esta tese pretende contribuir para o estudo e an��lise dos factores relacionados com as t��cnicas de aquisi����o de imagens radiol��gicas digitais, a qualidade diagn��stica e a gest��o da dose de radia����o em sistema de radiologia digital. A metodologia encontra-se organizada em duas componentes. A componente observacional, baseada num desenho do estudo de natureza retrospectiva e transversal. Os dados recolhidos a partir de sistemas CR e DR permitiram a avalia����o dos par��metros t��cnicos de exposi����o utilizados em radiologia digital, a avalia����o da dose absorvida e o ��ndice de exposi����o no detector. No contexto desta classifica����o metodol��gica (retrospectiva e transversal), tamb��m foi poss��vel desenvolver estudos da qualidade diagn��stica em sistemas digitais: estudos de observadores a partir de imagens arquivadas no sistema PACS. A componente experimental da tese baseou-se na realiza����o de experi��ncias em fantomas para avaliar a rela����o entre dose e qualidade de imagem. As experi��ncias efectuadas permitiram caracterizar as propriedades f��sicas dos sistemas de radiologia digital, atrav��s da manipula����o das vari��veis relacionadas com os par��metros de exposi����o e a avalia����o da influ��ncia destas na dose e na qualidade da imagem. Utilizando um fantoma contraste de detalhe, fantomas antropom��rficos e um fantoma de osso animal, foi poss��vel objectivar medidas de quantifica����o da qualidade diagn��stica e medidas de detectabilidade de objectos. Da investiga����o efectuada, foi poss��vel salientar algumas conclus��es. As medidas quantitativas referentes �� performance dos detectores s��o a base do processo de optimiza����o, permitindo a medi����o e a determina����o dos par��metros f��sicos dos sistemas de radiologia digital. Os par��metros de exposi����o utilizados na pr��tica cl��nica mostram que a pr��tica n��o est�� em conformidade com o referencial Europeu. Verifica-se a necessidade de avaliar, melhorar e implementar um padr��o de refer��ncia para o processo de optimiza����o, atrav��s de novos referenciais de boa pr��tica ajustados aos sistemas digitais. Os par��metros de exposi����o influenciam a dose no paciente, mas a percep����o da qualidade de imagem digital n��o parece afectada com a varia����o da exposi����o. Os estudos que se realizaram envolvendo tanto imagens de fantomas como imagens de pacientes mostram que a sobreexposi����o �� um risco potencial em radiologia digital. A avalia����o da qualidade diagn��stica das imagens mostrou que com a varia����o da exposi����o n��o se observou degrada����o substancial da qualidade das imagens quando a redu����o de dose �� efectuada. Prop��e-se o estudo e a implementa����o de novos n��veis de refer��ncia de diagn��stico ajustados aos sistemas de radiologia digital. Como contributo da tese, �� proposto um modelo (STDI) para a optimiza����o de sistemas de radiologia digital.

Blue-enhanced thin-film photodiode for dual-screen x-ray imaging

This article reports on a-Si:H-based low-leakage blue-enhanced photodiodes for dual-screen x-ray imaging detectors. Doped nanocrystalline silicon was incorporated in both the n- and p-type regions to reduce absorption losses for light incoming from the top and bottom screens. The photodiode exhibits a dark current density of 900 pA/cm(2) and an external quantum efficiency up to 90% at a reverse bias of 5 V. In the case of illumination through the tailored p-layer, the quantum efficiency of 60% at a 400 nm wavelength is almost double that for the conventional a-Si:H n-i-p photodiode.

A non-pixel image reader for continuous image detection based on tandem heterostructures

An optically addressed read-write sensor based on two stacked p-i-n heterojunctions is analyzed. The device is a two terminal image sensing structure. The charge packets are injected optically into the p-i-n writer and confined at the illuminated regions changing locally the electrical field profile across the p-i-n reader. An optical scanner is used for charge readout. The design allows a continuous readout without the need for pixel-level patterning. The role of light pattern and scanner wavelengths on the readout parameters is analyzed. The optical-to-electrical transfer characteristics show high quantum efficiency, broad spectral response, and reciprocity between light and image signal. A numerical simulation supports the imaging process. A black and white image is acquired with a resolution around 20 mum showing the potentiality of these devices for imaging applications.

Laser scanned photodiodes (LSPs) for image sensing

An optimized ZnO:Al/a-pin SixC1-x:H/Al configuration for the laser scanned photodiode (LSP) imaging detector is proposed and the read-out parameters improved. The effect of the sensing element structure, cell configuration and light source flux are investigated and correlated with the sensor output characteristics. Data reveals that for sensors with wide band gap doped layers an increase on the image signal optimized to the blue is achieved with a dynamic range of two orders of magnitude, a responsivity of 6 mA W-1 and a sensitivity of 17 muW cm(-2) at 530 nm. The main output characteristics such as image responsivity, resolution, linearity and dynamic range were analyzed under reverse, forward and short circuit modes. The results show that the sensor performance can be optimized in short circuit mode. A trade-off between the scan time and the required resolution is needed since the spot size limits the resolution due to the cross-talk between dark and illuminated regions leading to blurring effects.