Tris(2-Ethylhexyl) trimellitate (TOTM) a potential reference fluid for high viscosity. Part I: viscosity measurements at temperatures from (303 to 373)K and pressures up to 65MPa, using a novel vibrating-wire instrument

No literature data above atmospheric pressure could be found for the viscosity of TOTIVI. As a consequence, the present viscosity results could only be compared upon extrapolation of the vibrating wire data to 0.1 MPa. Independent viscosity measurements were performed, at atmospheric pressure, using an Ubbelohde capillary in order to compare with the vibrating wire results, extrapolated by means of the above mentioned correlation. The two data sets agree within +/- 1%, which is commensurate with the mutual uncertainty of the experimental methods. Comparisons of the literature data obtained at atmospheric pressure with the present extrapolated vibrating-wire viscosity measurements have shown an agreement within +/- 2% for temperatures up to 339 K and within +/- 3.3% for temperatures up to 368 K. (C) 2014 Elsevier B.V. All rights reserved.

Tris(2-Ethylhexyl) trimellitate (TOTM) a potential reference fluid for high viscosity. Part II: density measurements at temperatures from (293 to 373)K and pressures up to 85MPa

In Part I of the present work we describe the viscosity measurements performed on tris(2-ethylhexyl) trimellitate or 1,2,4-benzenetricarboxylic acid, tris(2-ethylhexyl) ester (TOTM) up to 65 MPa and at six temperatures from (303 to 373)K, using a new vibrating-wire instrument. The main aim is to contribute to the proposal of that liquid as a potential reference fluid for high viscosity, high pressure and high temperature. The present Part II is dedicated to report the density measurements of TOTM necessary, not only to compute the viscosity data presented in Part I, but also as complementary data for the mentioned proposal. The present density measurements were obtained using a vibrating U-tube densimeter, model DMA HP, using model DMA5000 as a reading unit, both instruments from Anton Paar GmbH. The measurements were performed along five isotherms from (293 to 373)K and at eleven different pressures up to 68 MPa. As far as the authors are aware, the viscosity and density results are the first, above atmospheric pressure, to be published for TOTM. Due to TOTM's high viscosity, its density data were corrected for the viscosity effect on the U-tube density measurements. This effect was estimated using two Newtonian viscosity standard liquids, 20 AW and 200 GW. The density data were correlated with temperature and pressure using a modified Tait equation. The expanded uncertainty of the present density results is estimated as +/- 0.2% at a 95% confidence level. Those results were correlated with temperature and pressure by a modified Tait equation, with deviations within +/- 0.25%. Furthermore, the isothermal compressibility, K-T, and the isobaric thermal expansivity, alpha(p), were obtained by derivation of the modified Tait equation used for correlating the density data. The corresponding uncertainties, at a 95% confidence level, are estimated to be less than +/- 1.5% and +/- 1.2%, respectively. No isobaric thermal expansivity and isothermal compressibility for TOTM were found in the literature. (C) 2014 Elsevier B.V. All rights reserved.

The K-Th derivatives of the immanant and the X-symmetric power of an operator

In recent papers, formulas are obtained for directional derivatives, of all orders, of the determinant, the permanent, the m-th compound map and the m-th induced power map. This paper generalizes these results for immanants and for other symmetric powers of a matrix.

The norm of the K- Th derivative of the X-symmetric power of an operator

In this paper, the exact value for the norm of directional derivatives, of all orders, for symmetric tensor powers of operators on finite dimensional vector spaces is presented. Using this result, an upper bound for the norm of all directional derivatives of immanants is obtained.

Reconstructing the architectural evolution of volcanic islands from combined K/AR, morphologic, tectonic, and magnetic data. The Faial Island exemple (Azores)

The morpho-structural evolution of oceanic islands results from competition between volcano growth and partial destruction by mass-wasting processes. We present here a multi-disciplinary study of the successive stages of development of Faial (Azores) during the last 1 Myr. Using high-resolution digital elevation model (DEM), and new K/Ar, tectonic, and magnetic data, we reconstruct the rapidly evolving topography at successive stages, in response to complex interactions between volcanic construction and mass wasting, including the development of a graben. We show that: (1) sub-aerial evolution of the island first involved the rapid growth of a large elongated volcano at ca. 0.85 Ma, followed by its partial destruction over half a million years; (2) beginning about 360 ka a new small edifice grew on the NE of the island, and was subsequently cut by normal faults responsible for initiation of the graben; (3) after an apparent pause of ca. 250 kyr, the large Central Volcano (CV) developed on the western side of the island at ca 120 ka, accumulating a thick pile of lava flows in less than 20 kyr, which were partly channelized within the graben; (4) the period between 120 ka and 40 ka is marked by widespread deformation at the island scale, including westward propagation of faulting and associated erosion of the graben walls, which produced sedimentary deposits; subsequent growth of the CV at 40 ka was then constrained within the graben, with lava flowing onto the sediments up to the eastern shore; (5) the island evolution during the Holocene involves basaltic volcanic activity along the main southern faults and pyroclastic eruptions associated with the formation of a caldera volcano-tectonic depression. We conclude that the whole evolution of Faial Island has been characterized by successive short volcanic pulses probably controlled by brief episodes of regional deformation. Each pulse has been separated by considerable periods of volcanic inactivity during which the Faial graben gradually developed. We propose that the volume loss associated with sudden magma extraction from a shallow reservoir in different episodes triggered incremental downward graben movement, as observed historically, when immediate vertical collapse of up to 2 m was observed along the western segments of the graben at the end of the Capelinhos eruptive crises (1957-58).

How human schematization and systematic errors take effect on sketch map formalizations

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies

Soil erosion after forest fires: evaluation of mitigation measures applied to drainage channels in the northwest of Portugal

The development and implementation of measures which promote the reduction of the impacts of forest fires on soils is imperative and should be part of any strategy for forest and soil preservation and recovery, especially considering the actual scenario of continuous growth in the number of fires and burnt area. Consequently, with the dendrocaustologic reality that has characterized the Portuguese mainland in recent decades, a research project promoted by the Center for the Study of Geography and Spatial Planning (CEGOT) was implemented with the objective of applying several erosion mitigation measures in a burned area of the Peneda-Geres National Park in NW Portugal. This paper therefore seeks to present the measures applied in the study area within the project Soil Protec, relating to triggered channel processes and the results of preliminary observations concerning the evaluation of the effectiveness of erosion mitigation measures implemented, as well as their cost/benefit ratio.

Immunopathology of human schistosomiasis mansoni: II. NK activity and stimulation by specific antigen

Sixteen S. mansoni infected and untreated patients (5 with recent infection and 11 with chronic disease) were evaluated for their in vitro natural killer (NK) activity against the NK sensitive target K562 cell line. NK levels in 9 out of 11 patients (82%) with chronic disease were significantly lower (mean = 15 �� 6%),compared with patients recently infected (mean = 41 �� 9% p < 0.001) and with the control group (mean = 38 �� 13% p < 0.001). However, both patients and controls NK activity was stimulated by soluble adult worm antigens (SAWA), indicating that NK function even in the chronic stage of the infection is able to respond to the parasite antigens. These results suggest the possibility of NK cell participation as effector mechanism against S. mansoni.

Arithmetic-based binary-to-RNS converter modulo {2(n)+/- k} for jn-Bit dynamic range

In this brief, a read-only-memoryless structure for binary-to-residue number system (RNS) conversion modulo {2(n) +/- k} is proposed. This structure is based only on adders and constant multipliers. This brief is motivated by the existing {2(n) +/- k} binary-to-RNS converters, which are particular inefficient for larger values of n. The experimental results obtained for 4n and 8n bits of dynamic range suggest that the proposed conversion structures are able to significantly improve the forward conversion efficiency, with an AT metric improvement above 100%, regarding the related state of the art. Delay improvements of 2.17 times with only 5% area increase can be achieved if a proper selection of the {2(n) +/- k} moduli is performed.

Sensitive bi-enzymatic biosensor based on polyphenoloxidases���gold nanoparticles���chitosan hybrid film���graphene doped carbon paste electrode for carbamates detection

A bi-enzymatic biosensor (LACC���TYR���AuNPs���CS/GPE) for carbamates was prepared in a single step by electrodeposition of a hybrid film onto a graphene doped carbon paste electrode (GPE). Graphene and the gold nanoparticles (AuNPs) were morphologically characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, dynamic light scattering and laser Doppler velocimetry. The electrodeposited hybrid film was composed of laccase (LACC), tyrosinase (TYR) and AuNPs entrapped in a chitosan (CS) polymeric matrix. Experimental parameters, namely graphene redox state, AuNPs:CS ratio, enzymes concentration, pH and inhibition time were evaluated. LACC���TYR���AuNPs���CS/GPE exhibited an improved Michaelis���Menten kinetic constant (26.9 �� 0.5 M) when compared with LACC���AuNPs���CS/GPE (37.8 �� 0.2 M) and TYR���AuNPs���CS/GPE (52.3 �� 0.4 M). Using 4-aminophenol as substrate at pH 5.5, the device presented wide linear ranges, low detection limits (1.68��10��� 9 �� 1.18��10��� 10 ��� 2.15��10��� 7 �� 3.41��10��� 9 M), high accuracy, sensitivity (1.13��106 �� 8.11��104 ��� 2.19��108 �� 2.51��107 %inhibition M��� 1), repeatability (1.2���5.8% RSD), reproducibility (3.2���6.5% RSD) and stability (ca. twenty days) to determine carbaryl, formetanate hydrochloride, propoxur and ziram in citrus fruits based on their inhibitory capacity on the polyphenoloxidases activity. Recoveries at two fortified levels ranged from 93.8 �� 0.3% (lemon) to 97.8 �� 0.3% (orange). Glucose, citric acid and ascorbic acid do not interfere significantly in the electroanalysis. The proposed electroanalytical procedure can be a promising tool for food safety control.

Distributed controllers modeling through Petri nets with multi-asynchronous-channels

This paper proposes the concept of multi-asynchronous-channel for Petri nets. Petri nets extended with multi-asynchronous-channels and time-domains support the specification of distributed controllers, where each controller has a synchronous execution but the global system is asynchronous (globally-asynchronous locally-synchronous systems). Each multi-asynchronous-channel specify the interaction between two or more distributed controllers. These channels, together with the time-domain concept, ensure the creation of network-independent models to support implementations using heterogeneous communication networks. The created models support not only the systems documentation but also their validation and implementation through simulation tools, verification tools, and automatic code generators. An application example illustrates the use of a Petri net class extended with the proposed channels. �� 2015 IEEE.

Modula����o do estado redox em bact��rias por quinoxalinas

As quinoxalinas s��o compostos heteroc��clicos que t��m, entre outras, capacidades antimicrobianas, inclusivamente contra bact��rias resistentes aos antimicrobianos convencionais. Os mecanismos pelos quais estes compostos exercem a sua atividade ainda n��o est�� completamente esclarecido. O objetivo do presente estudo �� avaliar o efeito redox em sinergismo/antagonismo com as quinoxalinas em modelos de bact��rias com e sem resist��ncias a antimicrobianos. No que se refere aos compostos foram utilizados a quinoxalina 1,4-di��xido (QNX), 2-metil-3-benzilquinoxalina-1,4-di��xido (2M3BQNX), 2-metilquinoxalina-1,4-di��xido (2MQNX) e a 2-amino-3-cianoquinoxalina-1,4-di��xido (2A3CQNX). Quanto aos modelos procariotas, foram utilizados a Salmonella enterica, Klebsiella pneumoniae, Enterococcus faecalis, Staphylococcus saprophyticus, Enterobacter aerogenes, Enterobacter cloacae, Staphylococcus aureus ATCC 25923, Methicillin-resistant Staphylococcus aureus ATCC 43300, Escherichia coli TEM 201 e Escherichia coli TEM 180. Nos compostos qu��micos em que se verificou a Concentra����o M��nima Inibit��ria (CMI), realizou-se o estudo do comportamento do crescimento bacteriano. Relativamente ao estado redox, foi avaliado para cada estirpe sens��vel, atrav��s do r��cio GSH/GSSG, nas doses inibit��rias e n��o inibit��rias de cada composto. Os resultados apresentam que todos os compostos testados, �� exce����o do 2M3BQNX, t��m atividade antimicrobiana na maioria das estirpes, excetuando a E. faecalis e a S. saprophyticus. Os r��cios GSH/GSSG apontam para o efeito oxidante em K. pneumoniae e S. enterica e antioxidante na E. aerogenes. A conclus��o do estudo sugere que os compostos apresentam elevada capacidade antibacteriana e influ��ncia no equil��brio redox das bact��rias, podendo contribuir para o esclarecimento do mecanismo de a����o dos derivados das quinoxalinas 1-4 di��xido, nas bact��rias.

Characterisation of noisy speech channels in 2G and 3G mobile networks

As the wireless cellular market reaches competitive levels never seen before, network operators need to focus on maintaining Quality of Service (QoS) a main priority if they wish to attract new subscribers while keeping existing customers satisfied. Speech Quality as perceived by the end user is one major example of a characteristic in constant need of maintenance and improvement. It is in this topic that this Master Thesis project fits in. Making use of an intrusive method of speech quality evaluation, as a means to further study and characterize the performance of speech codecs in second-generation (2G) and third-generation (3G) technologies. Trying to find further correlation between codecs with similar bit rates, along with the exploration of certain transmission parameters which may aid in the assessment of speech quality. Due to some limitations concerning the audio analyzer equipment that was to be employed, a different system for recording the test samples was sought out. Although the new designed system is not standard, after extensive testing and optimization of the system's parameters, final results were found reliable and satisfactory. Tests include a set of high and low bit rate codecs for both 2G and 3G, where values were compared and analysed, leading to the outcome that 3G speech codecs perform better, under the approximately same conditions, when compared with 2G. Reinforcing the idea that 3G is, with no doubt, the best choice if the costumer looks for the best possible listening speech quality. Regarding the transmission parameters chosen for the experiment, the Receiver Quality (RxQual) and Received Energy per Chip to the Power Density Ratio (Ec/N0), these were subject to speech quality correlation tests. Final results of RxQual were compared to those of prior studies from different researchers and, are considered to be of important relevance. Leading to the confirmation of RxQual as a reliable indicator of speech quality. As for Ec/N0, it is not possible to state it as a speech quality indicator however, it shows clear thresholds for which the MOS values decrease significantly. The studied transmission parameters show that they can be used not only for network management purposes but, at the same time, give an expected idea to the communications engineer (or technician) of the end-to-end speech quality consequences. With the conclusion of the work new ideas for future studies come to mind. Considering that the fourth-generation (4G) cellular technologies are now beginning to take an important place in the global market, as the first all-IP network structure, it seems of great relevance that 4G speech quality should be subject of evaluation. Comparing it to 3G, not only in narrowband but also adding wideband scenarios with the most recent standard objective method of speech quality assessment, POLQA. Also, new data found on Ec/N0 tests, justifies further research studies with the intention of validating the assumptions made in this work.

Anemia de c��lulas falciformes na idade pedi��trica : contribui����o para o estudo das suas principais complica����es e indicadores de progn��stico

RESMO: Introdu����o: A anemia de c��lulas falciformes doen��a heredit��ria, com repercuss��o multi-org��nica, tem grande variabilidade na sua express��o cl��nica. Da�� o interesse do estudo de indicadores de progn��stico. A investiga����o realizada foi precedida de um resumo hist��rico incidindo sobre a compreens��o de aspectos fundamentais da doen��a ao longo dos tempos. Na primeira parte do estudo e ap��s revis��o bibliogr��fica, foram referidos dados da fisiopatologia como base para os estudos que integram a presente disserta����o. Abordou-se o estado da arte relativamente ��s complica����es, aos indicadores de progn��stico e �� terap��utica utilizada. Objectivos: Constitu��ram objectivos deste estudo realizado numa amostra populacional representativa: identificar as les��es a n��vel dos sistemas cardio-respirat��rio e nervoso central, avaliando-se as respectivas repercuss��es; avaliar a presen��a de indicadores de progn��stico entre as vari��veis seleccionadas; estudar a efic��cia e toxicidade da HU nos doentes com as formas graves da ACF. Para a prossecu����o destes objectivos foram delineados para al��m do estudo global tr��s estudos espec��ficos: Estudo 1- repercuss��o no sistema cardio-respirat��rio; Estudo 2- repercuss��o no sistema nervoso central; Estudo 3- terap��utica com hidroxiureia. Doentes e m��todos: Procedeu-se a um estudo prospectivo e multi-institucional durante um per��odo de tr��s anos tendo-se seleccionado para a amostra, e de acordo com crit��rios pr��-definidos, 30 doentes com ACF na fase est��vel da doen��a, com idades compreendidas entre os sete e os 18 anos, todos de origem africana �� excep����o de um caucasiano. O diagn��stico baseou-se em t��cnicas de electroforese e estudo molecular que definiu o genotipo da doen��a e a presen��a da delec����o da ���-talass��mia assim como os haplotipos da amostra populacional. Foram utilizadas diferentes metodologias para avaliar a exist��ncia de les��o pulmonar e cerebral. Atrav��s do estudo estat��stico foram seleccionadas diversas vari��veis como hipot��ticos indicadores de progn��stico. Estudo 1. Para determinar a exist��ncia de les��o a n��vel pulmonar usaram-se duas metodologias diferentes, a avalia����o da fun����o pulmonar com estudo da satura����o da Hb em O2 no sangue arterial e a tomografia computadorizada de alta resolu����o. Estudou-se tamb��m a poss��vel disfun����o card��aca como repercuss��o da les��o pulmonar, atrav��s do ecocardiograma, e os indicadores de progn��stico com significado estat��stico para a les��o encontrada. Estudo 2. O desenho deste estudo foi sobrepon��vel ao anterior, mas com metodologia adequada para o SNC. Procedeu-se ao estudo das les��es cerebrais por meio de exames imagiol��gicos, (RMN-CE e DTC) e de testes psicol��gicos. Correlacionaram-se as tr��s metodologias utilizadas e a import��ncia de cada uma para a decis��o de atitudes terap��uticas preventivas. Estudo 3. Consistiu num estudo aberto prospectivo n��o controlado com nove crian��as e adolescentes com formas graves de ACF, com o objectivo de avaliar a efic��cia da terap��utica com hidroxiureia, durante um per��odo de 24 meses. Todos os doentes completaram no m��nimo 15 meses de terap��utica, com uma dose final m��dia de 19���4 mg/K/dia. Resultados globais: Durante o per��odo anterior �� investiga����o caracterizou-se a amostra populacional estudada quanto ao fenotipo gen��tico, cl��nico e hematol��gico de acordo com os crit��rios utilizados por outros investigadores. Verificou-se: predom��nio do haplotipo Bantu na forma homozig��tica em 53% dos doentes; n��mero total de EVO ���3/ano em 87,5% dos doentes; crises de sequestra����o em 18,75%; dactilites no primeiro ano de vida em 31,2%; quadro de s��psis grave apenas num doente; crises de hiper-hem��lise em 50%; e STA em 59,38% dos doentes. Quanto ao fenotipo hematol��gico evidenciaram-se como factores de risco reticulocitose (13,1x103/���l) e hiperbilirrubin��mia (2,5 mg/dl) e como factores de bom progn��stico a presen��a de delec����o de um gene da ���-talass��mia em 46,9% dos doentes e valor m��dio de Hb 8,1 g/dl. Resultados dos estudos parcelares: Estudo 1. Deste estudo infere-se que a DPR ligeira foi diagnosticada em 70% dos doentes, uma vez que as altera����es da difus��o n��o foram estatisticamente significativas, o estudo dos gases no sangue n��o evidenciaram resultados anormais e a TCAR evidenciou altera����es em 43,3% dos doentes. Apenas num doente se verificou doen��a pulmonar obstrutiva relacionada com maior n��mero da STA.O estudo da disfun����o card��aca encontrada em 86,7% dos doentes n��o reflecte a repercuss��o da DPR a n��vel card��aco, podendo estar associada ��s altera����es fisiopatol��gicas da pr��pria anemia cr��nica. Encontraram-se indicadores de progn��stico hematol��gicos e cl��nicos. Entre os primeiros, valores de Hb ���8,5 g/dl e de HbF ���13% foram considerados indicadores de bom progn��stico para a les��o pulmonar. Em rela����o aos par��metros cl��nicos, as STA n��o foram consideradas indicadoras de progn��stico para a DPR ao contr��rio do que se verificou com o n��mero de EVO. Pela an��lise dos par��metros gen��ticos e socio-econ��micos provou-se a aus��ncia de rela����o estatisticamente significativa com les��o pulmonar. Estudo 2. Pela RMN-CE foram diagnosticados ES em 33,3% com uma localiza����o preferencial na subst��ncia branca profunda em 26,6% dos doentes. Relativamente aos par��metros hematol��gicos seleccionados, o valor m��dio da HbF 8,6% constitu��u um indicador de bom progn��stico para o aparecimento de ES, enquanto o valor m��dio de leuc��citos 12.39x103/��l foi considerado um indicador de mau progn��stico. No estudo do DTC apenas um doente apresentou aumento da velocidade do fluxo cerebral na ACM igual a 196 cm/segundos, associado a vasculopatia grave. Os testes psicol��gicos alterados em 80% dos doentes mostraram ser o m��todo mais sens��vel para detectar altera����es do neurodesenvolvimento, mas sem correla����o com os ES em 10% dos doentes. Real��a-se a baixa percentagem de DTC patol��gicos encontrados neste estudo em rela����o ao n��mero elevado de ES e de testes psicol��gicos alterados, n��o se verificando concord��ncia entre os tr��s exames. Dos indicadores de progn��stico estudados a ���-talass��mia foi considerada um factor de protec����o para o coeficiente de intelig��ncia da escala de Wechsler. Em rela����o a par��metros cl��nicos estudados os doentes com maior n��mero de EVO, tem em m��dia valores inferiores nos testes psicol��gicos. Estudo 3. Neste estudo verificou-se que o valor m��dio da HbF aumentou significativamente de 7,0��4% para 13,7��5,3% (p=0,028) ao fim de 15 meses de terap��utica com hidroxiureia. Clinicamente todos os doentes responderam significativamente com uma redu����o de 80% no n��mero de EVO, 69% no n��mero de internamentos, 76% no n��mero de dias de hospitaliza����o e 67% no n��mero de transfus��es. Deste modo comprovou-se n��o s�� a efic��cia desta terap��utica neste grupo pedi��trico como tamb��m a falta de efeitos secund��rios significativos. Considera-se a necessidade de estudos mais prolongados e em grande s��ries, para com seguran��a se usar a HU antes que a les��o org��nica se estabele��a, portanto logo nos primeiros anos de vida. Conclus��o: Na amostra populacional estudada foram evidenciadas les��es pulmonares e cerebrais na grande maioria dos doentes que condicionaram a sua qualidade de vida. Foram identificados indicadores de progn��stico que poder��o eventualmente ditar medidas terap��uticas precoces com o objectivo de diminuir a morbilidade e a mortalidade neste grupo et��rio. Demonstrou-se que a terap��utica com a HU foi eficaz e bem tolerada----------ABSTRACT: Background: Sickle cell anemia (SCA), a hereditary disease characterized by pain and lifetime multi-organic lesion, is a challenge for all that work with carriers of this disease. The clinical expression variability of SCA is a constant reality and a problem to be solved in the current world of investigation, for which the knowledge of prognostic indicators responsible for the different aspects of clinical evolution diversity wiil be an added value. The study is preceded by a historical summary of the most important factors in the evolution of SCA, which are in themselves, an incentive for future research. In the first part of the study, after an extensive bibliographical revision, physiopathology data is referred to in general and specifically regarding the target organs, that constituted the base for the studies presented in the dissertation. The state of the art for the complications to be studied, the choice of prognostic indicators and the therapeutics application, were approached for the renewed interest in the theme. Aims: In regard to the investigation, the objective was to study the lesions in the most affected organs of a chosen pediatric group, to investigate prognostic indicators for lung and cerebral lesions and to evaluate the protective effect of hydroxyurea in children with severe outcomes. Patients and methods: A prospective and multi-institutional study was carried out during a three-year period, February 1998 to March 2001, with children and adolescents followed up at a Immunohematology Outpatient Clinic of Dona Estef��nia's Hospital, Lisbon. Based in predefined criteria, 30 children with SCA were selected in a stable phase of the disease, aged from seven to 18 years old, all of whom were of African origin with exception of one who was Caucasian. The diagnosis was based on electrophoresis techniques and molecular study that allowed to define the genotype, the presence of deletional alpha-thalassemia as well as haplotypes in the population. Different methodologies were used to evaluate the existence of lung and cerebral lesion. Statistical study of the different variables selected the prognostic indicators. In Study 1, to determine the existence of lung lesion two different methodologies were used: pulmonar function study with arterial blood gases determination; and high resolution computerized tomography. Heart dysfunction as a repercussion of lung lesion was also studied through echocardiography, and prognostic indicators were statistically significant for lesions found. The design of Study 2 was similar to Study 1, but with the appropriate methodology for CNS. After neurological examination, which was normal in all patients (control group), cerebral lesions were studied with imagiologic exams (MRN-CE and TCD) and psychological tests. These three methodologies were correlated and the importance of each one in the decision of the therapeutic profilactic attitudes. Study 3 consisted of a controlled prospective open study in children with severe forms of SCA, with the aim of the evaluating therapeutic effectiveness of hydroxyurea, during a period of 24 months. Results: In the global overall study preceding the Studies 1,2 and 3, there were a prevalence of haplotype Bantu (53%) and other risk factors, namely the number of VOC (87,5%), sequestration crisis (18,75%), dactilytis in first year of life(31,2%), hyperhemolysis crisis (50%) and ATC in more than half of the patients (59,38%). This group of bad prognostic indicators, associated with the population of the lower class according to the Graffar scale, demonstrates the importance of primary health care services, information provided to the children and their relatives, as well as the interest in prophylactic therapeutics, specific screening and prenatal diagnosis. Study 1. It was evident from this study that slight RPD was diagnosed in 70% of the patients, because alterations of the diffusion had no statistical significance and arterial blood gases determinations were normal. Only one patient had restrictive lung disease related with numerous ACS. However ACS was not considered a prognostic indicator for RPD, contrary to the number of EVO. HRTC revealed discreet fibrotic lines that could be related with slight RPD, but the lack of correlation of these two exams (33%) supports the value of lung function tests for precocious diagnosis of RPD. Heart dysfunction was found in 86,7% of patients, does not reflect the repercussion of RPD, but with the physiopathology of chronic anemia. Hematologic and clinical prognostic indicators were found. Good prognostic indicators for the non-evolution of RPD with average Hb values of ��� 8,5 g/dl and average HbF values of ���13%, respectively. The genetic and social-economic factors had no statistical significance; nevertheless, they were more prevalent among Bantu haplotype (53,3%) in patients with RPD. Study 2. RMN-CE detected SI in 33,3% of the patients, with preferential location in deep white substance in 26,6% and in front lobe in 20%. This distribution can be related to structural aspects of the brain and with the high sensibility of this organ to hypoxia. From the hematological parameters selected, average HbF value 8,6% and average leucocyte count 12.39x103/��l were prognostic indicators with different meaning to SI. The increase in the total bilirubin related to hyperhemolysis clinically explains the genesis of SI In the TCD study, only one patient had increased cerebral flow speed >196 cm/sec in CMA, which corresponded to serious vasculopathy in AngioMR. This patient never present previously neurological symptoms and had several hyperhemolysis crisis and VOC as risk factors. Low percentage of pathological TCD in this study, in relation to the high number of SI and altered tests, although without correlation among the three exams, is probably attributed to factors related to the methodology, aspects of cerebral physiopathology or perhaps a sign of good prognostic if the duration of study had not been so short. TCD should be used as a screening method in the age groups with higher risk of AVC and should never be considered separately in prophylactic therapeutics indication. Psychological tests were the most sensitive method to detect neurodevelopment impairment; in 80% of patients the neuropsychologics tests were altered, but without correlation with SI (10%). Since SI can become evident during the first two years of life and develop with time, the first psychological tests should be carried out between 3 and 5 years of age to timely be referred to special education and stimulation programs. Prognostic indicators to psychological tests were also found: alpha-thalassemia was found to be a protection factor of the IQ, just as other hematologic factors (hematocrit, MGCV and erythrocytes count). In relation to clinical parameters, although without statistical significance, patients with larger number of VOC had average lower scores versus the average in tests, except in TP. Results from different studies were conclusive as to the type of lesion found and the importance of prognostic indicators. Study 3. All the patients completed a minimum of 15 months therapeutic treatment with the final average daily dose of 19��4 mg/kg/day. The average value of the fetal hemoglobin increased significantly from 7,0��3,9% to 13,7��5,3% (p=0.028). The HbF average values increased from 6% to 15% after 15 months of therapeutic treatment. Clinically there was a reduction of 80% in the number of VOE , 69% in the number of hospitalization, 76% in the number of days of hospitalization and 67% in the number of transfusions. Once again the effectiveness of this treatment in this pediatric group, as well as the lack of any significant secondary effects, was evident. The study confirms the need for further detailed research in order to safely effect the appropriate treatment prior to the development of organic lesions, which ideally should be in the first year of life. Conclusions: These results allow us to clarify the importance of either pulmonary lesions or either nervous central system impairment among patients, children and adolescents, with sickle cell anemia. These lesions were demonstrated in most of the patients studied compromising their quality of life and the mortality. The treatment with HU is proved to be effective and having low toxicity.

Imagens da T��cnica na Fic����o Cient��fica. A Obra de Philip K. Dick no Contexto Sociot��cnico

Disserta����o para obten����o do grau de Doutor em Ci��ncias da Comunica����o Especialidade de Comunica����o e Cultura