Occult HBV infection status among chronic hepatitis C and hemodialysis patients in Northeastern Egypt: regional and national overview

INTRODUCTION: Occult hepatitis B infection (OBI) is considered to be one of the major risks for patients suffering from end-stage renal disease (ESRD) on regular hemodialysis (HD) and patients with chronic hepatitis C virus (HCV) infection. This study compared the prevalence of OBI among these two high-risk groups in the Suez Canal region, Northeastern Egypt, to obtain a better national overview of the magnitude of OBI in this region. METHODS: Serum samples were collected from 165 HD patients and 210 chronic HCV-infected patients. Anti-HCV antibody, hepatitis B surface antigen (HBsAg), total hepatitis B core (anti-HBc) antibody, and hepatitis B surface antibody (anti-HBs) were detected by enzyme-linked immunosorbent assay (ELISA). HCV RNA was detected using a quantitative real-time RT-PCR assay, and HBV was detected using a nested PCR. RESULTS: All patients were negative for HBsAg. A total of 49.1% and 25.2% of the patients in the HD and HCV groups, respectively, were anti-HBc-positive. In addition, more anti-HBs-positive patients were detected in the HD group compared to the HCV group (52.1% and 11.4%, respectively). Three cases were positive for HBV DNA in the HD group, while eighteen positive cases were detected in the HCV group. Both study groups showed significant differences in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) level as well as anti-HBc, anti-HBs and HBV-DNA positivity. CONCLUSIONS: OBI was more prevalent among chronic HCV patients than HD patients in the Suez Canal region, Egypt, with rates of 8.5% and 1.8%, respectively. However, more precise assessment of this infection requires regular patient follow-up using HBV DNA detection methods.

Development and application of NMR techniques to study water-in-CO2 microemulsions

Self-assembly is a phenomenon that occurs frequently throughout the universe. In this work, two self-assembling systems were studied: the formation of reverse micelles in isooctane and in supercritical CO2 (scCO2), and the formation of gels in organic solvents. The goal was the physicochemical study of these systems and the development of an NMR methodology to study them. In this work, AOT was used as a model molecule both to comprehensively study a widely researched system water/AOT/isooctane at different water concentrations and to assess its aggregation in supercritical carbon dioxide at different pressures. In order to do so an NMR methodology was devised, in which it was possible to accurately determine hydrodynamic radius of the micelle (in agreement with DLS measurements) using diffusion ordered spectroscopy (DOSY), the micellar stability and its dynamics. This was mostly assessed by 1H NMR relaxation studies, which allowed to determine correlation times and size of correlating water molecules, which are in agreement with the size of the shell that interacts with the micellar layer. The encapsulation of differently-sized carbohydrates was also studied and allowed to understand the dynamics and stability of the aggregates in such conditions. A W/CO2 microemulsion was prepared using AOT and water in scCO2, with ethanol as cosurfactant. The behaviour of the components of the system at different pressures was assessed and it is likely that above 130 bar reverse microemulsions were achieved. The homogeneity of the system was also determined by NMR. The formation of the gel network by two small molecular organogelators in toluene-d8 was studied by DOSY. A methodology using One-shot DOSY to perform the spectra was designed and applied with success. This yielded an understanding about the role of the solvent and gelator in the aggregation process, as an estimation of the time of gelation.

Vascular lesions of the lumbar epidural space: magnetic resonance imaging features of epidural cavernous hemangioma and epidural hematoma

The authors report the magnetic resonance imaging diagnostic features in two cases with respectively lumbar epidural hematoma and cavernous hemangioma of the lumbar epidural space. Enhanced MRI T1-weighted scans show a hyperintense signal rim surrounding the vascular lesion. Non-enhanced T2-weighted scans showed hyperintense signal.

Plasma nitriding of AA2011 alloy and surface characterization by NDT techniques

Al-Cu alloys are widely used in the aerospace and automotive industries due to their high specific strength in some tempered conditions. However, due to poor corrosion and wear resistance, they are often anodized and/or painted. Plasma nitriding has been proposed as an alternative, though the developments in this technique are still in a recent stage for Al alloys. Electrical characterization techniques are well implemented NDTs in the industry because of good accuracy associated with lower cost, compared to other methods. Some, like eddy currents and 4-point probe techniques, are often used in coating inspection. The objective of this study was to perform Al nitriding at low temperatures to minimize the tempering initial condition damage and to assess the feasibility of eddy currents technique as a method for evaluating surface properties. The work developed can be divided in two stages. The first one was the process tuning, done at the Shibaura Institute of Technology, in Tokyo; and the second was the electrical characterization done in Faculdade de Ciências e Tecnologia, UNL. Low temperature nitriding of AA2011 alloy specimens was successfully achieved. Electrical conductivity results show that lift-off measurements by eddy currents testing can be related to surface properties.

Endovascular techniques for placement of long-term chemotherapy catheters

PURPOSE: To analyze the results from using endovascular techniques to place long-term chemotherapy catheters when advancing the catheter using the external jugular vein is difficult due to obstructions or kinking. METHODS: Between July 1997 and August 2000, 320 long-term chemotherapy catheters were placed, and in 220 cases the external jugular vein was used as the primary venous approach. In 18 of these patients, correct positioning was not achieved and several endovascular techniques were then utilized to overcome these obstacles, including manipulation of a J-wire with a moveable core, venography, and the exchange wire technique. RESULTS: In 94.5% of the patients with difficulties in obtaining the correct positioning, we were able to advance the long-term catheter to the desired position with the assistance of endovascular techniques. CONCLUSIONS: Venography and endovascular guidance techniques are useful for the placement of long-term catheters in the external jugular vein.

Distúrbios osteomioarticulares : lombalgia e escoliose : prevalência e fatores associados : um estudo analítico e transversal em adolescentes da região do Algarve

RESUMO - Introdução: Os distúrbios osteomioarticulares envolvem diversas condições donde se destacam a lombalgia e a escoliose, a primeira considerando o fato que a sua prevalência tem vindo a aumentar em adolescentes consistindo num problema crescente de saúde pública que envolve custos indiretos e a escoliose pela ausência de estudos nacionais. Diversos fatores físicos, genéticos, mecânicos, comportamentais e ambientais podem estar envolvidos na patogénese das lombalgias e escolioses. O ambiente escolar, incluindo as posturas adotadas pelos alunos e o transporte das mochilas escolares, e alguns hábitos de estilos de vida constituem fatores que podem contribuir para o desenvolvimento destes distúrbios osteomioarticulares. Este estudo também aborda o estado ponderal, nomeadamente o excesso de peso e a obesidade, pois este é referido frequentemente como um potencial fator de risco destes distúrbios osteomioarticulares (apesar de ainda apresentar controvérsia na literatura), além de ser, por si só, atualmente considerado como um dos mais graves problemas de saúde pública a nível mundial. Objetivos do estudo: (1) determinar a prevalência pontual, anual e ao longo da vida de lombalgia, assim como a prevalência de escoliose em adolescentes da região do Algarve; (2) identificar os fatores associados ao desenvolvimento destes distúrbios osteomioarticulares; (3) determinar a prevalência de excesso de peso e de obesidade e explorar a sua eventual associação com a prevalência de lombalgia e escoliose em adolescentes; (4) comparar os resultados obtidos nos diferentes métodos antropométricos (Índice de massa corporal - IMC, medição das pregas cutâneas e circunferência abdominal) e verificar a sua concordância. Material e métodos: O desenho deste estudo foi de natureza observacional, analítico e transversal. O estudo foi aprovado pela Comissão de Ética da Administração Regional de Saúde do Algarve, pela Direção Regional de Educação do Algarve, pela Direção-Geral de Inovação e de Desenvolvimento Curricular, Ministério da Educação e Ciência, e pelas Direções dos Agrupamentos de Escolas que participaram do projeto. A amostra incluiu 966 adolescentes da região do Algarve, sul de Portugal, com idades compreendidas entre os 10 e 16 anos (12,24±1,53 anos), sendo 437 (45,2%) do sexo masculino e 529 (54,8%) do feminino. O método de amostragem foi aleatório estratificado, com base nos concelhos da região do Algarve, assumindo que poderia existir heterogeneidades geográficas. Os instrumentos de medida foram aplicados num único momento (2011/2012) e incluíram o Questionário de Lombalgia e Hábitos Posturais para caracterizar a presença de lombalgia e os hábitos posturais adotados pelos alunos em casa e na escola, o escoliómetro para avaliar a presença de escoliose, a balança, o estadiómetro (sendo posteriormente calculado o IMC), o adipómetro e a fita métrica. A análise dos dados incluiu técnicas de estatística descritiva, gráficas e analíticas aplicadas à todas as variáveis em estudo. Para determinar a associação entre as variáveis do estudo foi utilizada a estatística inferencial, nomeadamente o teste de independência do Qui-quadrado. Para analisar as correlações entre as medidas obtidas com os métodos antropométricos (na sua forma quantitativa), foi utilizado o coeficiente de Spearman. A influência das diversas variáveis na presença de lombalgia foi aferida através de regressões logísticas binárias, sendo os resultados apresentados como odds ratios brutos e ajustados e respetivos intervalos de confiança. Resultados: O presente estudo revelou uma elevada prevalência de lombalgia (anual: 47,2%; pontual: 15,7%; ao longo da vida: 62,1%). As raparigas apresentaram 2,05 de probabilidade de apresentar lombalgia comparativamente aos rapazes (IC 95%: 1,58-2,65; p<0,001), assim como os alunos com idades mais avançadas (13-16 anos) comparativamente aos mais novos (10-12 anos) que tiveram 1,54 de chances (IC 95%: 1,19-1,99; p=0,001). Os alunos que indicaram adotar uma postura de sentado com a coluna vertebral posicionada incorretamente apresentaram 2,49 de probabilidade de revelar lombalgia (IC 95%: 1,91-3,24; p<0,001), os alunos que afirmaram se posicionar de forma inadequada para assistir televisão ou jogar videojogos tiveram a probabilidade de 2,01 (IC 95%: 1,55- 2,61; p<0,001) e aqueles que adotaram a postura de pé incorretamente tiveram 3,39 de chance de apresentar lombalgia (IC 95%: 2,19-5,23; p<0,001). A escoliose esteve presente em 41 (4,2%) alunos. As raparigas apresentaram a maior prevalência (4,5% versus 3,9%) do que os rapazes e o mesmo foi observado nas raparigas que apresentaram a menarca tardia (8,6% versus 3,3%) e os que foram classificados como magros (7,1%), não sendo no entanto estas diferenças estatisticamente significativas. Relativamente à prevalência de excesso de peso e obesidade, os valores variaram de 31,6%, 61,4% e 41,1% de acordo com a medição do IMC, pregas cutâneas e circunferência abdominal, respetivamente. Os valores obtidos com a avaliação dos três métodos antropométricos apresentaram um elevado alto grau de correlação entre o IMC e as pregas cutâneas (p<0,001; r=0,712), entre o IMC e circunferência abdominal (p<0,001; r=0,884) e entre a circunferência abdominal e as pregas cutâneas (p<0,001; r=0,701). Conclusões: O presente estudo revelou valores de prevalência de lombalgia semelhante a estudos anteriores sendo que os alunos com idade mais avançada, ou do sexo feminino ou aqueles que adotavam a postura sentada e de pé de forma inadequada ou os que transportavam indevidamente a mochila escolar apresentaram a maior prevalência. Quanto à presença de escoliose, observou-se uma baixa prevalência não sendo verificada nenhuma associação significativa com os fatores analisados. Relativamente ao estado ponderal, verificou-se uma elevada prevalência de excesso de peso e obesidade, com a utilização dos três métodos antropométricos: IMC, medição das pregas cutâneas e circunferência abdominal, tendo sido verificado um elevado grau de correlação entre estes três métodos antropométricos. Este estudo contribuiu para determinar a magnitude destes distúrbios osteomiarticulares nesta população específica, assim como seus possíveis fatores associados. De acordo os resultados obtidos no presente estudo, torna-se necessário ações de intervenção nas escolas, envolvendo não somente os alunos, mas toda a comunidade escolar, com o objetivo de prevenção destes distúrbios osteomioarticulares através da promoção de hábitos de vida saudável.

Revisão e proposta de melhoria do sistema HACCP do Matadouro Regional do Alto Alentejo

A presente dissertação foi desenvolvida em colaboração com o Matadouro Regional do Alto Alentejo

COMPOSIÇÃO QUÍMICA E PERCENTUAL DE ADEQUAÇÃO DA DIETA REGIONAL DE MANAUS - AM.

A dieta regional de Manaus foi avaliada nutricionalmente por meio da análise química e percentual de adequação, tomando-se como referencial os padrões da National Academy of Science (19Ô9). A dieta foi elaborada utilizando-se os dados de Shrimpton & Giugliano (1979), para famílias com rendimentos de até dois salários mínimos mensais e preparadae de acordo com as técnicas culinárias habitualmente utilizadas pela população. Doe resultados obtidos, observou-se um déficit calorico de 54,3% para o homem adulto e 13,4% para a mulher adulta. Pas 1906 Kcal totale, os glicídios contribuíram com 60%, lipídios 20% e proteínas 20%. Quantitativamente, as proteínas estavam em níveis adequados, embora parte delas pudessem estar eendo utilizadas com finalidade energética. Dos minerais, o cálcio estava mais deficiente com um percentual de adequação da ordem de 50%. 0 ferro mostrou-se deficiente para a mulher adulta quando comparado com as necessidades recomendadae. Em relação ao teor de retino! proveniente do B-caroteno da dieta, o percentual foi de 12,6% e 15,0% respectivamente para homem e mulher. De acordo com os dados obtidos, concluiu-se que a dieta não atende às recomendações preconizadas para a maioria dos nutrientes estudados.

BIODISPONIBILIDADE DE ZINCO EM DIETA REGIONAL DE MANAUS, AM. ESTUDO EM RATOS

Foi estudada a biodisponibilidade de zinco em ratos recebendo uma dieta regional de Manaus, AM. A dieta foi elaborada segundo os dados de SHRIMPTON & GIUGLIANO, (1979) para famílias com rendimentos inferiores a 2 salários mínimos. O ensaio biológico com ratos da linhagem Wistar se baseou inicialmente, na depleção de zinco e vitamina A na lactação, adaptação dos filhotes com a dieta regional por 7 dias e período de repleção onde se realizou a suplementação com zinco de acordo com as recomendações do "COMMITTEE ON LABORATORY ANIMAL DIETS" (1979). Os resultados nos permitiram concluir que a quantidade de zinco presente na dieta, avaliada pelos parâmetros de medida de biodisponibilidade de zinco como crescimento, concentração nos órgãos e de enzima zinco dependente, foi utilizada adequadamente pelos animais, provavelmente pelos fatores promotores da dieta.

The reasons behind the progression in PISA scores: An education production function approach using semi-parametric techniques

Research Masters

Synthesis and characterization of novel 4H-pyran-4-ylidene indole-based heterocyclic systems for several optical applications

The development of organic materials displaying high two-photon absorption (TPA) has attracted much attention in recent years due to a variety of potential applications in photonics and optoelectronics, such as three-dimensional optical data storage, fluorescence imaging, two-photon microscopy, optical limiting, microfabrication, photodynamic therapy, upconverted lasing, etc. The most frequently employed structural motifs for TPA materials are donor–pi bridge–acceptor (D–pi–A) dipoles, donor–pi bridge–donor (D–pi–D) and acceptor–pi bridge-acceptor (A–pi–A) quadrupoles, octupoles, etc. In this work we present the synthesis and photophysical characterization of quadrupolar heterocyclic systems with potential applications in materials and biological sciences as TPA chromophores. Indole is a versatile building block for the synthesis of heterocyclic systems for several optoelectronic applications (chemosensors, nonlinear optical, OLEDs) due to its photophysical properties and donor electron ability and 4H-pyran-4-ylidene fragment is frequently used for the synthesis of red light-emitting materials. On the other hand, 2-(2,6-dimethyl-4H-pyran-4-ylidene)malononitrile (1) and 1,3-diethyl-dihydro-5-(2,6-dimethyl-4H-pyran-4-ylidene)-2-thiobarbituric (2) units are usually used as strong acceptor moieties for the preparation of π-conjugated systems of the push-pull type. These building blocks were prepared by Knoevenagel condensation of the corresponding ketone precursor with malononitrile or 1,3-diethyl-dihydro-2-thiobarbituric acid. The new quadrupolar 4H-pyran-4-ylidene fluorophores (3) derived from indole were prepared through condensation of 5-methyl-1H-indole-3-carbaldehyde with the acceptor precursors 1 and 2, in the presence of a catalytical amount of piperidine. The new compounds were characterized by the usual spectroscopic techniques (UV-vis., FT-IR and multinuclear NMR - 1H, 13C).

Toxicity measurement techniques for building materials with wastes

The innovative Horizon 2020 program sponsored by the European Union (EU) aims to promote and develop processes of waste integration in construction materials. However, several potential health hazards caused by building materials have been identified and, there-fore, there is an ongoing need to develop new recycling methods for hazardous wastes and effi-cient barriers in order to prevent toxic releases from the new construction solutions with wastes. This paper presents an overview that focus on two main aspects: the identification of the health risks related to radioactivity and heavy metals present in building materials and identification of these toxic substances in new construction solutions that contain recycled wastes. Different waste materials were selected and distinct methodologies of toxicity evaluation are presented to analyse the potential hazardous, the feasibility of using those wastes and the achievement of op-timal construction solutions involving wastes.

Ancient materials and techniques to improve the earthen building durability

A substantial part of the world building heritage has been performed by earthen building. The durability of this existing heritage and mainly of the new buildings built with earth is particularly conditioned by the erosion caused by water action, especially in countries with high levels of rainfall. This research aims to contribute to the increase of knowledge about the ancient building techniques that provide enhanced durability. It is possible to analyse the ancestral practices used to protect the earth material from the water action in order to understand how the old earthen buildings were preserved over the centuries, resisting to harsh weather conditions. Among these techniques are: the incorporation of biopolymers (such as oils or fats from animal or vegetable origin); the addition of some minerals; and the earth stabilization with lime. However, this knowledge seems to be forgotten, probably due to the prejudice related to earthen constructions, which several times are associated with a poor building. This research also focuses on the study of new methods of earth stabilization with lime and biopolymers, adapting the ancient knowledge to improve the durability related to the water action. Therefore, alternative solutions can be obtained to improve the performance of earthen buildings, mainly the resistance of the material in the presence of water, reducing its permeability to water. In addition, with the proposed solutions it is possible to obtain good levels of water vapour permeability, one of the major advantages of the construction with earth.