ABSTRACT Objective: The purpose of these guidelines is to provide specific recommendations for the surgical treatment of neck metastases in patients with papillary, follicular, and medullary thyroid carcinomas. Materials and methods: Recommendations were developed based on research of scientific articles (preferentially meta-analyses) and guidelines issued by international medical specialty societies. The American College of Physicians’ Guideline Grading System was used to determine the levels of evidence and grades of recommendations. The following questions were answered: A) Is elective neck dissection indicated in the treatment of papillary, follicular, and medullary thyroid carcinoma? B) When should central, lateral, and modified radical neck dissection be performed? C) Could molecular tests guide the extent of the neck dissection? Results/conclusion: Recommendation 1: Elective central neck dissection is not indicated in patients with cN0 well-differentiated thyroid carcinoma or in those with noninvasive T1 and T2 tumors but may be considered in T3-T4 tumors or in the presence of metastases in the lateral neck compartments. Recommendation 2: Elective central neck dissection is recommended in medullary thyroid carcinoma. Recommendation 3: Selective neck dissection of levels II–V should be indicated to treat neck metastases in papillary thyroid cancer, an approach that decreases the risk of recurrence and mortality. Recommendation 4: Compartmental neck dissection is indicated in the treatment of lymph node recurrence after elective or therapeutic neck dissection; “berry node picking” is not recommended. Recommendation 5: There are currently no recommendations regarding the use of molecular tests in guiding the extent of neck dissection in thyroid cancer.

RESUMO Resíduos de MDF (MediumDensityFiberboard) gerados nas indústrias de móveis de madeiras, geralmente, são depositados em locais inadequados, causando impactos ambientais. Este trabalho teve como objetivo desenvolver materiais porosos com a incorporação de resíduo de MDF (5, 10 e 15% de resíduo) em massas cerâmicas estruturais. As características mineralógicas, químicas e térmicas das massas foram analisadas. Corpos de prova (50mm x15mm x 5mm) foram conformados por prensagem uniaxial (13,3 MPa), os quais foram secos à 110 ºC/24 h e sinterizados à 750, 850 e 950 °C. Posteriormente, estes foram submetidos às seguintes caracterizações: absorção de água, densidade aparente, porosidade aparente e módulo de ruptura à flexão. As características mineralógicas e microestruturais, após queima, também foram analisadas. Os resultados evidenciaram que, até 10% do resíduo de MDF em forma de pó, poderá ser incorporado em massas cerâmicas estruturais para produção de materiais cerâmicos, como blocos porosos isolantes acústicos e térmicos. A porosidade aparente foi de 31,7%, a densidade aparente foi de 1,6 g/cm3 e o módulo de ruptura a flexão foi de 11,5 MPa.

ABSTRACT MDF industrial wastes (Medium Density Fiberboard) generated in the wood furniture industries, have been causing serious environmental impacts, since their improperly disponishment in the nature. In light of this, the purpose of this work is to develop new structural ceramic compositions, containing 5, 10 and 15% by mass of MDF waste. The mineralogical, chemical and thermal characteristics of the masses were analyzed. Test bodies (50mm x15mm x 5mm) were shaped by uniaxial press (13.3 MPa), which were dried at 110º C/24h and sintered at 750, 850 and 950 °C. Subsequently, these were subjected to the following characterizations: Water absorption, apparent density, apparent porosity and flexion rupture module. The mineralogical and microstructural characteristics, after firing, were also analyzed. The results showed that up to 10% of the residue of MDF in the form of powder could be incorporated into structural ceramic masses for the productions of ceramic materials, such as acoustic and thermal insulation porous bricks. The apparent porosity was 31.7 %, bulk density was 1.6 g/cm3, the flexural strength was 11.5 MPa.

The properties of ceramic materials and microstructural changes are dependent on the raw materials from which they are made and on the manner in which they are processed, from the composition to the established thermal treatment, heating rate, and firing temperature. In this study, the influence of some processing parameters (formulation, maturation time, and firing temperature) on the physical-mechanical properties and microstructural aspects of ceramic pieces produced from natural aluminosilicates was investigated. Because Brazil does not have many quality ball clays reserves, bentonite was included as a plasticizing agent in this study. The formulations were submitted to maturation for a period of one to four weeks and their characteristics were determined to evaluate plasticity. Following this, the specimens were extruded and subjected to heat at temperatures of 1200, 1300, and 1400ºC. The physical-mechanical properties determined were: water absorption, linear retraction, and flexural strength. Statistical analysis was applied. The results showed that, for the analyzed masses, neither the maturation time nor the physical and mechanical properties analyzed had influence on plasticity. The firing temperature was the factor that generated the greatest alteration in results, increasing the mechanical resistance and altering the size and interlocking of the mullite needles.

A chuva dirigida, considerada um dos fatores de maior degradação em vedações externas, pode acarretar desde problemas estéticos até a decomposição dos materiais que compõem as fachadas e alvenarias. Nessa pesquisa, concretos destinados à produção de blocos para alvenarias foram submetidos a ensaios que simularam 20 anos de exposição, tomando, como referência, a precipitação pluvial do Estado da Paraíba. Avaliou-se a substituição de 10, 15 e 20% do cimento por metacaulim, utilizando-se, como parâmetro de avaliação, a perda de massa dos corpos de prova ao final do ensaio. Verificou-se que os concretos com metacaulim apresentaram valores de perda de massa maiores do que concretos de referência, sem metacaulim, e que esses valores aumentam com a elevação do teor de substituição. Entretanto, para os traços com menor teor de cimento, o uso de 10% de metacaulim promoveu resultados similares aos de referência. Os resultados do ensaio estão compatíveis com a literatura para estudos de avaliação em situações de exposição real, porém estudos complementares deverão ser desenvolvidos para se correlacionarem os resultados laboratoriais obtidos com os resultantes de exposição a condições climáticas naturais.

Driving rain, considered one of the major factors in the degradation of external seals, may cause esthetic problems and material decomposition to facades and masonry. In the present research, the production of concrete hollow blocks for masonry underwent testing for which 20 years of exposure have been considered, taking into account the annual precipitation in the State of Paraíba. This was assessed by replacing 10, 15 and 20% of cement for metakaolin using as parameter the specimen’s mass loss at end of the test. It has was found that the concrete with metakaolin revealed values of weight loss greater than those of the reference concrete, without metakaolin, and that these values increased as the level of substitution increased. However, for mixtures with lower cement content, the use of 10% by metakaolin promoted results that have been considered similar to the reference. The test results are, therefore, consistent with those reported in literature for assessment studies on actual exposure situations; however, further studies will be developed to correlate the laboratory results obtained and from the resulting exposure to natural weather conditions.

A preocupação com o meio ambiente vem motivando diversas pesquisas sobre o uso de materiais pozolânicos em substituição parcial ao cimento em concretos e argamassas, entretanto poucos são os dados sobre tal uso em concretos destinados à produção de elementos prémoldados, concreto este que geralmente é denominado concreto seco ou sem abatimento, devido à baixa umidade requerida no processo de moldagem e prensagem. Este trabalho consistiu em um estudo preliminar sobre o uso de metacaulim em concreto seco, sendo analisados cinco traços de concreto com cinco teores de substituição em cinco tempos de cura, objetivando determinar quais os percentuais de substituição mais adequados, ou seja, aqueles que promovessem aumento na resistência à compressão simples e redução na absorção de água por imersão. Devido ao grande número de variáveis envolvidas, foi utilizado o planejamento experimental estatístico Delineamento Composto Central Rotacional (DCCR), sendo os resultados analisados pela Metodologia de Superfície de Resposta (MSR). A análise da superfície de resposta mostrou que, para todos os traços, os melhores resultados dentro dos parâmetros estabelecidos poderão ser encontrados com o uso de metacaulim em percentuais de 10% a 20% de substituição da massa do cimento aos 49 dias de cura.

The concern about the environment has motivated several studies on the use of pozzolanic materials as a partial replacement for cement in concrete and mortar. However, there are few data about such a use in concrete designed for the production of precast elements, which is usually called dry or no-slump concrete, due to the low humidity required in the process of molding and pressing. This paper reports a preliminary study on the use of metakaolin in no-slump concrete, analyzing five concrete mixtures with five levels of substitution, in five curing times, aiming to determine the most appropriate percentages of replacement, i.e., those that promote increase in compressive strength and reduction in water absorption by immersion. Due to the large number of variables involved, the statistical experimental design named Central Composite Rotational Design (CCRD) was used, and the results were analyzed using the Response Surface Methodology (RSM). The response surface analysis showed that for all concrete mixtures, the best results within the parameters established can be found with the use of metakaolin in percentages of 10% at 20% of replacement in the cement mass at 49 days of curing.

Mineral extraction and processing industries have been cited as sources of environmental contamination and pollution. However, waste recycling represents an alternative recovery option, which is interesting from an environmental and economic standpoint. In this work, recycling of kaolin processing waste in the manufacture of mullite-based ceramics was investigated based on the statistical design of mixture experiments methodology. Ten formulations using kaolin processing waste, alumina and ball clay were used in the experiment design. Test specimens were fired and characterized to determine their water absorption and modulus of rupture. Regression models were calculated, relating the properties with the composition. The significance and validity of the models were confirmed through statistical analysis and verification experiments. The regression models were used to analyze the influence of waste content on the properties of the fired bodies. The results indicated that the statistical design of mixture experiments methodology can be successfully used to optimize formulations containing large amount of wastes.

O caulim é um material com vasta gama de aplicações nos mais diversos setores industriais, como a indústria de papel e a cerâmica. No entanto, sua extração e beneficiamento provocam a geração de enorme quantidade de resíduos. Assim, esse trabalho tem por objetivo analisar a utilização do resíduo do beneficiamento do caulim como matéria-prima alternativa em argamassas para a construção civil. O resíduo foi caracterizado através da determinação de sua composição química, difração de raios X e determinação da distribuição granulométrica. Foram formuladas argamassas substituindo parcialmente a cal hidratada por resíduo. Em seguida, foram confeccionados corpos-de-prova e determinada sua resistência à compressão simples e à tração indireta. A substituição da cal por adições de até 20% de resíduo de caulim possibilitou o aumento da resistência das argamassas estudadas em até 80%. Com base nos resultados, pode-se concluir que o resíduo de caulim pode ser utilizado para a produção de argamassas para construção civil com propriedades mecânicas de acordo com a normalização e que a adição do resíduo pode melhorar a resistência mecânica das argamassas convencionais.

Kaolin is a material used in a wide range of applications in many industrial sectors, as the paper and the ceramic industry. However, the kaolin processing industry generates large amounts of waste. Thus, the aim of this work is to evaluate the kaolin processing waste suitability as an alternative raw material for the production of mortars. The waste was characterized by determining its chemical composition, particle size distribution, and X-ray diffraction. Mortars were prepared by partially substituting kaolin waste for hydrated lime. Test specimens were prepared and their compression and indirect tension strength determined. The substitution of the lime by additions of up to 20% of kaolin waste improved the mechanical strength of masonry mortars up to 80%. The mechanical properties of the alternative mortars are in accordance with standard values, which indicated that it is possible to use kaolin waste for the production of mortars. Moreover, the waste addition may improve the mechanical properties of the conventional mortars.

A study was made of the influence of ionic strength (S) on the apparent (AV) and plastic (PV) viscosities and water loss (WL) of sodium bentonite suspension with polymers. Na-bentonite was dispersed in water (4.86% w/w) of different ionic strengths (S = 0.0, 0.015, 0.030 and 0.045 M) followed by the addition of polymer. Three polymer samples were studied, i.e., low viscosity carboxymethyl cellulose (CMC BV), polyanionic cellulose (PAC), and partially hydrolyzed polyacrylamide (HPAM). The results indicated that the presence of salts and increased salinity greatly influence the apparent and plastic viscosities and water loss of bentonite suspensions with polymer.

A aditivação polimérica dos fluidos usados na perfuração de poços de petróleo é prática comum e dentre os aditivos mais usados, destacam-se o carboximetilcelulose (CMC) e a poliacrilamida parcialmente hidrolisada (PHPA), que dependendo das suas características, desempenham diferentes funções e são adicionados individualmente. Este trabalho objetiva o estudo de composições binárias de polímeros celulósicos e não-celulósicos visando o desenvolvimento de compósitos bentonita/polímeros para uso em fluidos à base de água. Foi estudada uma amostra de argila bentonítica sódica da Paraíba e três amostras de polímeros (CMC de baixa e alta viscosidade e PHPA). O dimensionamento das misturas de polímeros foi elaborado de forma a explorar composições básicas (100%-0%; 50%-50% e 0%-100%) como passo inicial. Os compostos poliméricos em três diferentes concentrações foram misturados à argila seca e, em seguida, preparados os fluidos de perfuração. Após repouso de 24 h, foram determinadas as viscosidades aparente e plástica e o volume de filtrado de acordo com as normas da Petrobras. Os resultados evidenciaram que a mistura de polímeros celulósicos com os não-celulósicos se mostrou mais eficiente na melhoria das propriedades reológicas e de filtração dos fluidos de perfuração à base de água. Desta forma, torna-se viável a combinação de matérias primas de características diferentes para a obtenção de compostos poliméricos a serem adicionados a argilas bentoníticas para o desenvolvimento do compósito bentonita/polímero para uso na perfuração de poços de petróleo.

The polymeric addictivation of fluids used in oil wells drilling is a common practice and among the addictives more used, is the carboximethyl cellullose (CMC) and the partially-hydrolyzed polyacrylamide (PHPA), and depending of their characteristics, carry out different functions and they are added individually. The objective of this work is study binary compositions of cellullosics and non-cellullosic polymers to development of bentonite/polymers compositions to use in water based drilling fluids. Was studied one sodic bentonite clay sample from Paraiba and three polimerics additives (low viscosity and high viscosity CMC and PHPA). The polymer mixtures was elaborated to explore the basic compositions (100%-0%; 50%-50% and 0%-100%) as initial step. The polymeric compositions in three different concentrations was mixed with dry clay and after the drilling fluids was prepared. Following 24 h fluid resting, the apparent and plastic viscosities and water loss were established according to Petrobras standards. The results evidenced that the cellullosic and non-cellullosic polymers mixture showed to be more efficient improving the rheologic and filtration properties of water based drilling fluids. This way, is able the combination of raw materials of different attributes to obtain polymeric compositions to be added on bentonitics intending the development of bentonite/polymer composite to wells drilling uses.

Os depósitos de argilas bentoníticas da Paraíba se constituem no maior e mais importante jazimento deste bem mineral do Brasil. Suas ocorrências estão situadas no Município de Boa Vista e seus depósitos encontram-se nas minas Lages, Bravo, Juá e Canudos. As bentonitas de Boa Vista ficaram conhecidas pela sua capacidade de inchar na presença de água, desenvolvendo géis tixotrópicos após tratamento com Na2CO3, bem como pela sua variedade de cores. Este trabalho tem como objetivo apresentar a caracterização mineralógica e as propriedades reológicas de três variedades de argilas bentoníticas de Boa Vista, denominadas de Bofe, Chocolate e Verde-lodo, provenientes cada uma delas de duas diferentes minas. As argilas foram caracterizadas por meio de ensaios de análise química, análise térmica diferencial e análise termogravimétrica. O estudo reológico foi realizado por meio da determinação das viscosidades aparente e plástica, em viscosímetro Fann 35A e o volume de filtrado em filtro-prensa Fann em dispersões com 4,86% em massa de argila aditivadas com diferentes teores de Na2CO3. Os resultados mostraram que embora as argilas provenientes das diferentes minas apresentem cores e composição mineralógica semelhantes, apresentam propriedades reológicas bastante diferentes após tratamento com Na2CO3. Esse comportamento diferenciado classifica e condiciona a aplicação industrial de cada variedade de argila.

The deposits of bentonite clays at Paraíba are the bigger and more important deposits of this type of mineral in Brazil. It is located in Boa Vista city and can be found in Lages, Bravo, Juá, and Canudos mines. These clays became well known because of their capacity of swelling in the presence of water, developing thixotropic gels after treatment with Na2CO3, as well as by their different colours. The aim of this work is to present a comparative study of the mineralogical composition and rheology of three bentonite clays namely Bofe, Chocolate and Verde-lodo, each one from two different mines of Boa Vista, PB. The clays were caracterizated by chemical analysis, differential thermal analysis and thermogravimetric analysis. The natural bentonite clays were transformed into sodium bentonite by addition of different concentrations of Na2CO3. The dispersions were prepared with 4.86wt% in order to measure their apparent and plastic viscosities by Fann 35A viscosimeter and water loss by pressing-filter. The results showed that the bentonite clays from different mines present similar colours and mineralogical composition, but their rheological properties became different after treatment with Na2CO3. This difference at this behavior allows to classify and to indicate the industrial application of each type of clay.

The aim of this work is to characterize physically and mineralogically six samples of natural and industrialized bentonites from Paraíba, Brazil, and to study its rheological properties to be used as a components of water based drilling fluids. Also it is intended to compare the evolution of the mineralogical composition and rheology of these clays after 40 years of exploitation. The natural bentonite clays were transformed into sodium bentonite by addition of concentrated Na2CO3 solution. The suspensions were prepared with 4.86% w/w to measure their rheological properties (apparent and plastic viscosities and water loss). The results showed that: i) the samples present typical mineralogical compositions of bentonites, but after four decades of exploitation, presents inferior quality and ii) among the clays samples, only one presented satisfactory rheological properties be used as a components of water based drilling fluids.

RESUMO Com o objetivo de se obter aglomerantes pozolânicos a partir da reciclagem de rejeitos da construção civil, foram estudadas duas amostras de entulho, uma de resíduo de cerâmica vermelha e uma pozolana artificial, e duas amostras de cal. As amostras foram caracterizadas através de análise química, análise térmica diferencial, difração de raios-X, área específica e determinação da atividade pozolânica. As amostras de entulho e resíduo cerâmico foram moídas em moinho de bolas por 90 min e a de pozolana artificial em moinho de discos. Foram preparadas argamassas alternativas, no traço 1:3 e, como aglomerante, cal pozolânica, em composições 30-70%, 40-60% e 50-50% de cal e pozolana. Os corpos de prova foram curados por períodos de 7, 28 e 60 dias e submetidos a ensaios de resistência a compressão simples, cujos resultados mostram que a reciclagem de rejeitos é promissora, podendo gerar elementos construtivos de baixo custo e que seu uso implica na preservação do meio ambiente e na melhoria da qualidade de vida da população em geral.

ABSTRACT With the objective of obtaining lime-pozzolana cements from the recycling of civil construction waste, four samples consisting of ceramic residue (bricks and tiles), artificial pozzolana and two samples of hydrated lime were studied. All samples were characterized by chemical analysis, thermal differential analysis, X-ray diffraction, specific area and activity pozzolanic. The waste samples and ceramic residues were ground in a ball mill for 90 min and that of artificial pozzolana in a disk mill. The alternative mortars were prepared using as aglomerate lime pozzolanic cement in proportion of 30-70, 40-60 and 50-50% of lime and pozzolana, respectively. The specimens were cured for periods of 7, 28 and 60 days and submitted to the RCS trials. The results obtained show that the recycling of civil construction waste is a promising technique which may generate low cost elements, destined for civil works and its use implies in the preservation of the environment and in the improvement of the quality of life of the population in general.

A criptosporidíase de 25 pacientes adultos, com síndrome da imunodeficiência adquirida (AIDS) foi tratada por meio da paromomicina, sendo administrados, por via oral, 500mg quatro vezes ao dia, durante duas semanas. Houve boa resposta clínica, representada por redução considerável ou cessação da diarréia em 19 (76%), tendo a tolerância sido satisfatória. Somente em um (4%) doente ocorreram tonturas e, em outro (4%), surgiram náuseas e vômitos, possivelmente devido à medicação. Controle parasitológico de cura teve lugar em 20, verificando-se na maioria deles (75%) persistência do agente causal. Apesar do freqüente insucesso quanto à eliminação do parasita, a melhoria obtida na maioria das vezes e a apreciável tolerância ao medicamento, tornam a paromomicina opção muito útil na terapêutica da infecção intestinal causada pelo Cryptosporidium sp nos indivíduos com AIDS.

The authors treated with paromomycin 25 patients, with AIDS and cryptosporidiasis. The drug was given orally in a doses of 500mg qid, for a period of 14 days. Tolerance was good, with just two cases of mild side-effects. Clinical improvement was obtained in 19 (76%) patients. Parasitological cure, however, occurred only in a low percentage (25%). In some cases where initial success was observed, recrudescence occurred after some weeks or few months, but with retreatment again clinical improvement was obtained. Even if it does not lead to frequent parasite eradication, the good clinical results and tolerance permit us to consider paromomycin one of the few drugs effective for the treatment of cryptosporidial diarrhea in AIDS patients. Studies with maintainance therapy are indicated.