Resistotipagem e transfer��ncia genética de plasm��dios de resistência entre coliformes e vibrios potencialmente patog��nicos para o homem isolados de camar��o (litopenaeus vannamei) comercializado em Natal-Rio Grande do Norte

Cinquenta amostras de camar��o fresco e refrigerado (Litopenaeus vannamei) foram coletadas em diferentes pontos de comercializa����o na cidade de Natal RN. As amostras foram maceradas em um gral est��ril e 25 gramas semeadas em 225mL de APA contendo 1% de NaCl e 25g em 225mL de CL incubadas a 35��C - 24 horas. O crescimento em APA foi semeado em placas de ��gar TCBS, incubadas a 35��C-24h para isolamento de Vibrio e Aeromonas. O crescimento do CL foi semeado em Agar EAM, para isolamento de coliformes. Dos 102 isolados, 91 (89,2%) pertenciam ao g��nero Vibrio e 11 (10,8%) ao g��nero Aeromonas, com predomin��ncia de V. cholerae n��o O1/n��o O139, V. alginolyticus, V. carchariae e V. parahaemolyticus K- e A. veronii biogrupo sobria , A. jandaei, A. schubertii, A. veronii biogrupo veronii e A. hydrophila. A menor efici��ncia entre os antimicrobianos foi da AMP (57,8% de resistência) seguida da AMK (29,4%) e TCY (21,6%). As 39 cepas de Vibrio e Aeromonas multirresistentes se distribu��ram em 10 perfis distintos, sendo que um revelou cinco marcos (AMP, CHL, NIT, SXT e TCY) em um isolado de V. carchariae de camar��o, adquirido em supermercados. O ��ndice MAR, nas 39 cepas variou de 0,28 a 0,42, sugerindo que s��o de risco na transfer��ncia e difus��o da resistência na cadeia alimentar. Ap��s a cura plasmidial pelo tratamento com AO de 24 cepas multirresistentes e com resistência intermedi��ria de v��brio e aeromonas escolhidas aleatoriamente, 13 perderam totalmente a resistência e 7 perderam parcialmente, sendo que o maior percentual de perda da resistência ocorreu nas cepas de V. cholerae n��o O1 e n��o O139 (6 cepas), se concentrando nos marcos de resistência a AMP (13), AMK (11), TCY(8) e CIP(3). Os resultados da conjuga����o realizada entre amostras de Vibrio xvi curadas e a E. coli K12C600 demonstraram que 78,5% das culturas de Vibrio testadas revelaram capacidade de transfer��ncia para o gene que confere resistência a AMP e 28,5% para a TCY. Dos coliformes, E. coli foi a mais frequente, seguida de Citrobacter spp, isoladas em 40,3% e 27,5% das amostras respectivamente. AMP foi o antimicrobiano menos eficaz, seguido de TCY. As 11 cepas multirresistentes se distribu��ram em 9 perfis distintos, um deles constitu��do de cinco marcos (AMP, NIT, TCY, CHL, SXT), albergados em uma cepa de Klebsiella spp, oriunda de camar��o adquirido em supermercado, similar ao resultado obtido em V. carchariae. Conclui-se que, os camar��es marinhos frescos e refrigerados, comercializados em Natal-RN evidenciaram contamina����o com coliformes, v��brios e aeromonas multirresistentes a antimicrobianos comumente utilizados na terapia m��dica e veterin��ria, e que, possivelmente, a transfer��ncia de genes de resistência entre bact��rias se constitui um s��rio problema de sa��de p��blica

Soropreval��ncia da infec����o pelo Trypanosoma cruzi no munic��pio de Caic��, RN, e caracteriza����o genética por RAPD do parasito isolado de humanos e de triatom��neos no semi��rido potiguar

Trypanosoma cruzi infection was evaluated in 390 resident individuals in different rural communities of Caic�� municipality, State of Rio Grande do Norte (RN). Of 28 investigated communities the soroprevalence of T. cruzi infection was 2.8% in eight rural communities individuals. The epidemiological characteristics of seropositive shown that the age ranged from 22 to 64 years, being significantly raised from 31 years (90.9%). The female gender was predominant and low education degree. Those individuals reported that they never donated blood, but they had direct contact with triatomines bug. The isolation of the parasite was performed by blood culture and xenoculture methods to determine the genetic variability of the samples. Twenty seven T. cruzi isolates were analyzed by RAPD as genetic marker using three random primers (M13-40, gt11-F and L15996). The T. cruzi isolates showed 73.7% of shared bands considering the average obtained with the three primers, and were genetically well correlated. Using this marker it was possible to separate the populations of the parasite in three distinct groups. The first group composed by isolates obtained of triatomines and humans from four different districts (Caic��, Cara��bas, Serra Negra doNorte and Governador Dix-Sept Rosado); the second contained isolates obtained of triatomines of two different species (T. brasiliensis and P. lutzi) captured in Cara��bas and Serra Negra do Norte. The third grouped isolates obtained from humans of Angicos and Caic�� municipalities. In different localities of distinct mesoregions, State of RN, a profile genetic well correlated was identified among all isolates and the presence of three distinct groups of the parasite circulating among vertebrate and invertebrate hosts

Estrutura genética de popula����es de Amphobotrys ricini, agente causal do mofo cinzento da mamoneira

The gray mold, causal organism Amphobotrys ricini, is one of the major diseases of castor bean. Difficulties in managing plant disease arises form the limited understanding of the genetic structure of A. ricini, their complexity and variability make it difficult to control. Genetic structure can be used to infer the relative impact of different forces that influence the evolution of pathogen populations, that allow to predict the potencial for pathogen populations to envolve in agricultural ecosystems. Growers protect their crop by applying fungicides, but there aren t fungicides to provide significant control of gray mold of castor bean. The objectives of this work were use RAPD to determine the genetic structure of A. ricini subpopulations in Para��ba and assay the sensitivity of A. ricini isolates to azoxystrobin and carbendazim. To determine the genetic structure of A. ricini subpopulations in Para��ba, 23 isolates were colleted from two different geographic location (subpopulation). These isolates were analysed by RAPD using 22 random decamer primers, purchased from OPERON, produced a total of 80 markers polimorphics. The resulting matrixes were analysed using PopGene version 1.32. Sensitivity to azoxystrobin and carbendazim of 30 isolates, colleted form Para��ba and Alagoas, was estimated based on spore germination and colony growth inhibition. The stock solutions were added toV8 medium after sterilization to produce final concentrations of 0, 0.01, 0.1, 1, 10, and 100 ��g/ml of carbendazim and 0, 0.001, 0.01, 0.1, 1, and 10 ��g/ml of azoxystrobin. All statistical analyses were performed using SAS to estimate the dose that inhibited fungal growth by 50% (ED50 values). The genetic diversity within subpopulations (Hs=0,271) accounted for 92% of the total genetic diversity (Ht=0,293), while genetic diversity between subpopulations (Gst = 0,075) represented only 7,5%. The estimated number of migrants per generation (NM ) was 6,15. Nei s average gene identity across 80 RAPD loci was 0,9468. Individual ED50 values, for the 30 isolates screened for their sensitivity to azoxystrobin, ranged From a maximum of 0,168 ��g/ml to a minimum of 0,0036 ��g/ml. The ED50 values for carbendazim varied within the range of 0,026 to 0,316 ��g/ml

Caracteriza����o da resistência do algodoeiro a Ramularia areola e variabilidade molecular do pat��geno

This research was conducted with the aim to study the genetic and pathogenic structure of Ramularia areola isolates collected in Brazil and to characterize the resistance response in cotton plants to ramularia spot. The genetic variability of 28 isolates of R. areola was studied using RAPD markers. The pathogenicity evaluation was realized by the inoculation of 6 isolates on cotton varieties Guazuncho-2 (Gossypium hirsutum) and VH8-4602 (Gossypium barbadense). The inheritance of disease resistance was studied using an artificially inoculated population of F2 individuals derived from the intercross of Guazuncho-2 (susceptible variety) end VH8-4602 (resistant variety), and also the parents and F1 individuals. Molecular polymorphism between the G. hisutum varieties DeltaOpal (suscetible) and CNPA CO-11612 (resistant) was estimated by 118 SSR and 24 AFLP markers. The parental genotypes Guazuncho-2 and VH8-4602 were selected for mapping, and then Recombinant Inbred Lines (RIL��s) derived from this crossing were evaluated with SSR 12 markers. The analysis of population structure of R. areola revealed that the three subpopulations were genetically simillar (Gst=0.18), and the isolates from Goi��s and Minas Gerais were more similar to each other (0,92). This probability can be related to the relatively high gene flow among the three subpopulations (Nm=2.20). The isolates R. areola 9.1, from Minas Gerais State and 8.1 and 8.3 from Goi��s State were the most aggressive ones to the susceptible variety Guazuncho-2. The variety VH8-4602 presented high level of resistance to ramularia spot. No differential interaction was observed between the pathogens and the analyzed varieties, and the resistance was classified as horizontal. The quantification of disease by number of necrotic lesions and number of spores in individual plants of F1 and F2 generations from the crossing between the varieties Guazuncho-2 and VH8-4602 presented continuous distribution, suggesting polygenic resistance. The resistance is probabilly recessive, since necrotic lesions and sporulation were observed on F1 plants. The molecular polymorphism between DeltaOpal e CNPA CO-11612 lineages was low (6%), then would be difficult to accomplish molecular mapping of disease resistance using this intercross. With the genotyping of the RIL s it was verified that 25% of the markers segregated in the proportions proposed by Mendel s Law and 75% of the studied markers presented segregation distortion in favor to the parental G. hirsutum. Both the low genetic variability of the pathogen and the number of resistance genes suggest that durable genetic resitance may be achieved

A prescri����o de medicamentos por enfermeiros na aten����o prim��ria �� sa��de no Brasil: caracteriza����o, normatiza����o, forma����o e li����es aprendidas.

O papel do enfermeiro como prescritor vem se ampliando em muitos pa��ses nos ��ltimos anos, em diferentes situa����es e amplitudes de a����o, se configurando como pr��tica avan��ada na enfermagem. No Brasil, a prescri����o de medicamentos por enfermeiros est�� prevista na Lei do Exerc��cio Profissional desde 1986, e permite a esse profissional, a prescri����o de medicamentos estabelecidos em programas de sa��de p��blica. Esse estudo tem como objetivo geral analisar as determina����es e perspectivas da prescri����o de medicamentos por enfermeiros nos protocolos da Estrat��gia Sa��de da Fam��lia. Os objetivos espec��ficos s��o: apreender a atual situa����o internacional da prescri����o de medicamentos por enfermeiros em compara����o a essa pr��tica no Brasil identificando semelhan��as e diferen��as; identificar os contornos legais e normativos da prescri����o de medicamentos por enfermeiros no Brasil apontando sua hist��ria, tend��ncias e desafios; caracterizar o modelo de prescri����o de medicamentos por enfermeiros nos protocolos de Aten����o Prim��ria �� Sa��de no Brasil; investigar poss��veis lacunas entre forma����o, capacita����o, autoavalia����o e pr��tica da prescri����o de medicamentos na Aten����o Prim��ria �� Sa��de na perspectiva do enfermeiro. Trata-se de Estudo de Caso Exemplar com abordagem qualitativa atrav��s de Revis��o Bibliogr��fica, An��lise Documental e Grupo Focal com enfermeiros. A an��lise dos dados deu-se por meio da An��lise de Conte��do e An��lise Qualitativa de Conte��do. Os resultados revelam que a categoria da enfermagem contribuiu para a legaliza����o da prescri����o, por��m n��o para a sua legitima����o; na Aten����o Prim��ria �� Sa��de, essa atribui����o est�� consolidada por meio de protocolos e legisla����o, embora sem estrat��gia clara de acompanhamento pelo Minist��rio da Sa��de; observa-se resistência em algumas normatiza����es dentro do setor sa��de. Quanto aos protocolos, observou-se n��o h�� exig��ncia de pr��-requisitos na maioria deles; h�� possibilidade de diagn��stico pelo enfermeiro na gravidez, nutri����o infantil e doen��as sexualmente transmiss��veis; observou-se variados graus de autonomia; amplo grupo de medicamentos prescritos por enfermeiros. Dos 37 participantes do Grupo Focal, 97,3% eram do sexo feminino; 54% formados h�� menos de 10 anos, 27% entre 10 e 20 anos, 16,2% h�� mais de 20 anos; 83,8% com especializa����o em Sa��de P��blica. Todos os enfermeiros relataram insufici��ncia da disciplina de farmacologia para instrumentalizar a pr��tica prescritiva. Destacou-se a necessidade de p��s-gradua����o; a import��ncia da experi��ncia cl��nica; falta de discuss��es e capacita����o. Apenas alguns se autoavaliaram como competentes para prescrever, outros revelam medo de rea����o adversa a medicamentos. Conclui-se que h�� tend��ncia da prescri����o de medicamento por enfermeiros permanecer apenas na legalidade e o principal desafio �� alcan��ar a legitimidade. Confirma-se uma pr��tica prescritiva sem requisitos, diversidade de orienta����es induzindo a multiplicidade de a����es que pode afetar a qualidade da prescri����o. H�� lacunas entre forma����o, capacita����es e exig��ncias cotidianas da prescri����o de medicamentos por enfermeiros na Aten����o Prim��ria �� Sa��de. No Brasil se faz premente pesquisa para avaliar o impacto, a qualidade e a seguran��a da prescri����o de medicamentos por enfermeiros. A experi��ncia internacional sugere tamb��m que essa prescri����o deve ser apoiada pelo coletivo de enfermeiros, com robusto plano de capacita����o nacional, al��m de governan��a e apoio local.

Avalia����o demogr��fica, clinico-laboratorial e genética de indiv��duos com lupus eritematoso sist��mico e artrite reumat��ide residentes em regi��o tropical

The aetiology of autoimmunes disease is multifactorial and involves interactions among environmental, hormonal and genetic factors. Many different genes may contribute to autoimmunes disease susceptibility. The major histocompatibility complex (MHC) genes have been extensively studied, however many non-polymorphic MHC genes have also been reported to contribute to autoimmune diseases susceptibility. The aim of the present study was to evaluate the influence of SLC11A1 gene in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Ninety-six patients with SLE, 37 with RA and 202 controls enrolled in this case-control study, were evaluated with regard to demographic, genetic, laboratorial and clinical data. SLE mainly affects females in the ratio of 18 women for each man, 88,3% of the patients aged from 15 to 45 years old and it occurs with similar frequency in whites and mulattos. The rate of RA between women and men was 11:1, with 77,1% of the cases occurring from 31 to 60 years. The genetic analysis of the point mutation -236 of the SLC11A1 gene by SSCP did not show significant differences between alleles/genotypes in patients with SLE or RA when compared to controls. The most frequent clinical manifestations in patients with SLE were cutaneous (87%) and joint (84.9%). In patients with RA, the most frequent out-joint clinical manifestation were rheumatoid nodules (13,5%). Antinuclear antibodies were present in 100% of the patients with SLE. There was no significant relation between activity of disease and presence of rheumatoid factor in patients with RA, however 55,6% of patients with active disease presented positive rheumatoid factor. Significant association between alleles/genotypes of point mutation -236 and clinical manifestations was not found

An��lise da estabilidade genética de c��lulas-tronco mesenquimais humanas

Human multipotent mesenchymal stromal cells (MSCs), also known as mesenchymal stem cells, have become an important and attractive therapeutic tool since they are easily isolated and cultured, have in vitro expansion potential, substantial plasticity and secrete bioactive molecules that exert trophic effects. The human umbilical cord as a cell source for cell therapy will help to avoid several ethical, political, religious and technical issues. One of the main issues with SC lines from different sources, mainly those of embryonic origin, is the possibility of chromosomal alterations and genomic instability during in vitro expansion. Cells isolated from one umbilical cord exhibited a rare balanced paracentric inversion, likely a cytogenetic constitutional alteration, karyotype: 46,XY,inv(3)(p13p25~26). Important genes related to cancer predisposition and others involved in DNA repair are located in 3p25~26. Titanium is an excellent biomaterial for bone-implant integration; however, the use can result in the generation of particulate debris that can accumulate in the tissues adjacent to the prosthesis, in the local bone marrow, in the lymph nodes, liver and spleen. Subsequently may elicit important biological responses that aren��t well studied. In this work, we have studied the genetic stability of MSC isolated from the umbilical cord vein during in vitro expansion, after the cryopreservation, and under different concentrations and time of exposition to titanium microparticles. Cells were isolated, in vitro expanded, demonstrated capacity for osteogenic, adipogenic and chondrogenic differentiation and were evaluated using flow cytometry, so they met the minimum requirements for characterization as MSCs. The cells were expanded under different concentrations and time of exposition to titanium microparticles. The genetic stability of MSCs was assessed by cytogenetic analysis, fluorescence in situ hybridization (FISH) and analysis of micronucleus and other nuclear alterations (CBMN). The cells were able to internalize the titanium microparticles, but MSCs preserve their morphology, differentiation capacity and surface marker expression profiles. Furthermore, there was an increase in the genomic instability after long time of in vitro expansion, and this instability was greater when cells were exposed to high doses of titanium microparticles that induced oxidative stress. It is necessary always assess the risks/ benefits of using titanium in tissue therapy involving MSCs, considering the biosafety of the use of bone regeneration using titanium and MSCs. Even without using titanium, it is important that the therapeutic use of such cells is based on analyzes that ensure quality, security and cellular stability, with the standardization of quality control programs appropriate. In conclusion, it is suggested that cytogenetic analysis, FISH analysis and the micronucleus and other nuclear alterations are carried out in CTMH before implanting in a patient

Estrutura genética populacional de Lutjanus analis cioba e Lutjanus jocu dent��o (Lutjanidae) ao longo do litoral brasileiro

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior

Processo biotecnol��gico voltado a produ����o de estoques poliploides do camar��o-branco litopenaeus vannamei (decapoda, penaeidae)

without practical results so far. Protocols used in biotechnological cultured aquatic organisms aimed at increasing growth rates and disease resistance, have been studied and perfected. Among the available techniques, the application of chromosomal manipulation, although still nascent, is presented as a tool aimed at mitigating ecological and economical issues in shrimp farming. The polyploidization artificial method already employed in fish and shellfish, has been widely researched for use in farmed shrimp. Some limitations of this method of expansion in shrimp refer to a better knowledge of cytogenetic aspects, the level of sexual dimorphism and performance in growing conditions. To contribute on some of these issues, the present study aimed to characterize cytogenetic species Litopenaeus vannamei (Decapoda) and Artemia franciscana (Anostraca), analyze the effectiveness of methods for detection of ploidy, through the use of flow cytometry in processes of induction polyploidy cold thermal shock at different stages of development of newly fertilized eggs. Additionally, aimed also the qualitative and quantitative comparison of larval development between diploid and polyploid organisms, besides the identification of sexual dimorphism in L. vannamei, through geometric morphometrics. The results provide information relevant to the improvement and widespread use of biotechnological methods applied toward national productivity in shrimp farming

An��lise metagen��mica da microbiota de ambientes aqu��ticos do estado do Rio Grande do Norte - Brasil

The screening for genes in metagenomic libraries from soil creates opportunities to explore the enormous genetic and metabolic diversity of microorganisms. Rivers are ecosystems with high biological diversity, but few were examined using the metagenomic approach. With this objective, a metagenomic library was constructed from DNA soil samples collected at three different points along the Jundia��-river (Rio Grande do Norte-Brazil). The points sampled are from open area, rough terrain and with the direct incidence of sunlight. This library was analyzed functionally and based in sequence. For functional analysis Luria-Bertani solid medium (LB) with NaCl concentration varied from 0.17M to 0.85M was used for functional analysis. Positives clones resistant to hypersaline medium were obtained. The recombinant DNAs were extracted and transformed into Escherichia coli strain DH10B and survival curves were obtained for quantification of abiotic stress resistance. The sequences of clones were obtained and submitted to the BLASTX tool. Some clones were found to hypothetical proteins of microorganisms from both Archaea and Bacteria division. One of the clones showed a complete ORF with high similarity to glucose-6-phosphate isomerase which participates in the synthesis of glycerol pathway and serves as a compatible solute to balance the osmotic pressure inside and outside of cells. Subsequently, in order to identify genes encoding osmolytes or enzymes related halotolerance, environmental DNA samples from the river soil, from the water column of the estuary and ocean were collected and pyrosequenced. Sequences of osmolytes and enzymes of different microorganisms were obtained from the UniProt and used as RefSeqs for homology identification (TBLASTN) in metagenomic databases. The sequences were submitted to HMMER for the functional domains identification. Some enzymes were identified: alpha-trehalose-phosphate synthase, L-ectoina synthase (EctC), transaminase L-2 ,4-diaminobutyric acid (EctB), L-2 ,4-diaminobutyric acetyltransferase (EctA), L-threonine 3 dehydrogenase (sorbitol pathway), glycerol-3-phosphate dehydrogenase, inositol 3-phosphate dehydrogenase, chaperones, L-proline, glycine betaine binding ABC transporter, myo-inositol-1-phosphate synthase protein of proline simportadora / PutP sodium-and trehalose-6-phosphate phosphatase These proteins are commonly related to saline environments, however the identification of them in river environment is justified by the high salt concentration in the soil during prolonged dry seasons this river. Regarding the richness of the microbiota the river substrate has an abundance of halobacteria similar to the sea and more than the estuary. These data confirm the existence of a specialized response against salt stress by microorganisms in the environment of the Jundia�� river

Influ��ncia da vermiculita expandida na resistência �� compress��o e reologia de pastas cimentantes de po��os de petr��leo

Several problems related to the loss of hydraulic seal in oilwells, causing gas migration and/or contamination of the production zone by water, have been reported. The loss of the hydraulic seal is a consequence of cracks which can be occasioned either by the invasion of gas during the wait on cement or by the expansion of the casing causing the fracture of the cement sheath. In case of the pressure of the formation is higher than the pressure in the annulus, gas can migrate into the slurry and form microannulus, which are channels where gas migrates after the cement is set. Cracks can be also occasioned by the fracture of the cement sheath when it does not withstand the thermal and dynamic loads. In reservoirs where the oil is heavy, steam water injection operation is required in order to get the oil flowing. This operation increases the temperature of the casing, and then it expands and causes the fracture of the cement sheath in the annulus. When the failures on the cement are detected, remedial cementing is required, which raise costs caused by the interventions. Once the use of cement in the construction civil sector is older than its use in the petroleum sector, it is common to bring technologies and solutions from the civil construction and apply them on the petroleum area. In this context, vermiculite, a mineral-clay widely encountered in Brazil, has been used, on its exfoliated form, in the civil construction, especially on the manufacture of lights and fireproof concretes with excellent thermal and acoustical properties. It has already been reported in scientific journals, studies of the addition of exfoliated vermiculite in Portland cements revealing good properties related to oilwell cementing operations. Thus, this study aimed to study the rheological behavior, thickening time, stability and compressive strength of the slurries made of Portland cement and exfoliated vermiculite in 5 different compositions, at room temperature and heated. The results showed that the compressive strength decreased with the addition of exfoliated vermiculite, however the values are still allowed for oiwell cementing operations. The thickening time of the slurry with no exfoliated vermiculite was 120 min and the thickening time of the slurry with 12 % of exfoliated vermiculite was 98 min. The stability and the rheological behavior of the slurries revealed that the exfoliated vermiculite absorbed water and therefore increased the viscosity of the slurries, even though increasing the factor cement-water. The stability experiment carried out at 133 ��F showed that, there was neither sedimentation nor reduction of the volume of the cement for the slurry with 12 % of exfoliated vermiculite. Thus, the addition of exfoliated vermiculite accelerates the set time of the cement and gives it a small shrinkage during the wait on cement, which are important to prevent gas migration

Incorpora����o de res��duo cer��mico para preven����o da retrogress��o da resistência de cimentos de po��os de petr��leo submetidos �� inje����o de vapor

Steam injection is the most used thermal recovery method of oil nowadays because of the high degree of development of the technique that allows high recovery factors. However, injection of superheated steam into the reservoir affects the entire structure of the well, including the cemented layer that presents a retrogression of compressive strength and increases the permeability due to formation of more crystalline and denser phases at temperatures above 110 ��C. These changes result in failures in the cement that favor the entrance of formation fluids into the annulus space resulting in unsafe operations and restrictions in the economic life of the well. But the strength retrogression can be prevented by partial replacement of cement by silica-based materials that reduce the CaO/SiO2 ratio of cement slurries changing the trajectory of the reactions, converting those deleterious phases in phases with satisfactory mechanical strength and permeability. The aim of this study was to evaluate the behavior of a ceramic waste material rich in silica in partial and total substitution of a mineral additive used to fight the strength retrogression of cement slurries subjected to high temperatures. The evaluation was made by compression, X-ray diffraction (XRD) and thermogravimetry (TG/DTG). The samples were submitted to a cycle of low temperature (38 ��C) for 28 days and a cycle of low temperature followed by exposure to 280 ��C and 1000 psi by 3 days. The results showed that slurries with additions of up to 30% of the waste material are not enough to prevent the strength retrogression, while slurries with additions of the waste material combined with silica flour in various proportions produced hydrated products of low Ca/Si ratios that maintained the compressive strength at satisfactory levels

Avalia����o da corros��o em dutos por t��cnica gravim��trica e de resistência el��trica

With the increasing of demand for natural gas and the consequent growth of the pipeline networks, besides the importance of transport and transfer of oil products by pipeline, and when it comes to product quality and integrity of the pipeline there is an important role regarding to the monitoring internal corrosion of the pipe. This study aims to assess corrosion in three pipeline that operate with different products, using gravimetric techniques and electrical resistance. Chemical analysis of residues originated in the pipeline helps to identify the mechanism corrosive process. The internal monitoring of the corrosion in the pipelines was carried out between 2009 and 2010 using coupon weight loss and electrical resistance probe. Physico-chemical techniques of diffraction and fluorescence X-rays were used to characterize the products of corrosion of the pipelines. The corrosion rate by weight loss was analyzed for every pipeline, only those ones that has revealed corrosive attack were analyzed located corrosion rate. The corrosion potential was classified as low to pipeline gas and ranged from low to severe for oil pipelines and the pipeline derivatives. Corrosion products were identified as iron carbonate, iron oxide and iron sulfide

Efeito da adi����o de cargas minerais leves na resistência mec��nica de grautes para cimenta����o de po��os offshore

The preparation of cement slurries for offshore well cementing involves mixing all solid components to be added to the mixing water on the platform. The aim of this work was to study the formulation of pre-prepared dry mixtures, or grouts, for offshore oilwell cementing. The addition of mineral fillers in the strength of lightweight grouts applied for depths down to 400 m under water depths of 500 m was investigated. Lightweight materials and fine aggregates were selected. For the choice of starting materials, a study of the pozzolanic activity of low-cost fillers such as porcelain tile residue, microsilica and diatomaceous earth was carried out by X-ray diffraction and mechanical strength tests. Hardened grouts containing porcelain tile residue and microsilica depicted high strength at early ages. Based on such preliminary investigation, a study of the mechanical strength of grouts with density 1.74 g/cm3 (14.5 lb/gal) cured initially at 27 ��C was performed using cement, microsilica, porcelain tile residue and an anti-foaming agent. The results showed that the mixture containing 7% of porcelain tile residue and 7% of microsilica was the one with the highest compressive strength after curing for 24 hours. This composition was chosen to be studied and adapted for offshore conditions based on testes performed at 4 ��C. The grout containing cement, 7% of porcelain tile residue, 7% of active silica and admixtures (CaCl2), anti-foaming and dispersant resulted satisfactory rheology and mechanical strength after curing for 24 hours of curing

Avalia����o da atividade antimal��rica e citot��xica de plantas medicinais dos Biomas Caatinga e Amaz��nico

Resistance of Plasmodium falciparum to the usual antimalarials, as well as their adverse effects and high cost, has led to the search of new drugs against malaria. Several of these have been developed from medicinal plants based on ethnopharmacology, including the most widely used antimalarials today: quinine and artemisinin. In the present study schizonticide activity of extracts and fractions of a number of medicinal plants from the Caatinga and Amazon biomes were assessed based on ethnopharmacological and chemosystematic information. These included Ximenia americana, Maytenus rigida, Sideroxylon obtusifolium, Stryphnodendro coriaceum, Bowdichia virgiliodes, Schinopis brasiliensis and Picrolemma sprucei, the last, an Amazon species. Antimalarial tests of blood schizonticides were conducted in Swiss mice infected with P. berghei and in vitro against P. falciparum. In vitro cytotoxicity studies were carried out using HeLa, CHO, 3T3, Raw and HEPG2 cell lines. Except for X. americana, all species exhibited in vivo or in vitro antimalarial activity, inhibiting parasitic growth by up to 79%. Extracts exhibited moderate toxicity with dosedependent kinetics. In this sense, ethnopharmacological and chemosystematic approaches were shown to be useful and promising tools in the search of new drugs. These findings represent a significant contribution to scientific knowledge of the antimalarial potential of Brazilian flora, thereby opening perspectives for the development of new antimalarials