Estudo geoqu?mico e isot?pico de amostras de itabiritos dos sinclinais Gandarela e Ouro Fino, Quadril?tero Ferr?fero.

Programa de P?s-Gradua??o em Evolu??o Crustal e Recursos Naturais. Departamento de Geologia, Escola de Minas, Universidade Federal de Ouro Preto.Forma??es ferr?feras s?o rochas sedimentares que foram depositadas essencialmente no Pr?-cambriano, ricas em ferro que cont?m informa??es sobre a composi??o da ?gua do mar antiga, da evolu??o da vida e dos processos ocorridos no sistema da Terra primitiva. A forma??o ferr?fera de margem continental (tipo Lago Superior) da Forma??o Cau?, Quadril?tero Ferr?fero, Brasil, compreende um metassedimento qu?mico rico em ferro que foi alterado durante a circula??o hidrotermal de fluidos basais, metamorfismo de f?cies xisto verde a anfibolito, e enriquecimento superg?nico do ferro. O objetivo deste trabalho ? desenvolver e implementar m?todos para a determina??o de elementos-tra?o, especialmente os elementos terras raras (ETR) em amostras de itabiritos, e interpretar o comportamento do fracionamento do ferro (? 56Fe) e dos ETR na Forma??o Ferr?fera Cau? em um contexto diagen?tico, hidrotermal e metam?rfico. O m?todo implementado para an?lise de tra?os por ICP-MS ap?s dissolu??o ?cida e a metodologia desenvolvida para determina??o de ETR por LA-ICP-MS se mostraram adequados ao uso pretendido. An?lises litogeoqu?micas baseadas na parag?nese de amostras de dois testemunhos de sondagem com diferentes graus de altera??o destacam a import?ncia dos processos hidrotermais, metam?rficos e superg?nicos nas composi??es de REE e ?56Fe da forma??o de ferr?fera. O primeiro furo de sondagem ? proveniente do Sinclinal Ouro Fino (SOF) e apresenta litof?cies menos alteradas na base, seguidas de outras que sofreram altera??o hidrotermal e superg?nica. O segundo furo ? proveniente do Sinclinal Gandarela (SG) e possui itabiritos intensamente alterados por fluidos hidrotermais, enriquecimento superg?nico e intemperismo. O efeito do enriquecimento do ferro e do intemperismo ? melhor capturado ao longo do perfil de profundidade de cada furo pela rela??o inversa entre SiO2 e Fe2O3. Os valores de SiO2 s?o mais baixos e os valores de Fe2O3 mais altos perto da superf?cie. A presen?a de goethita a 500 m registra a profundidade m?xima desses processos no subsolo. As anomalias ETR e Y das litof?cies mais profundas e menos alteradas em ambos os n?cleos s?o t?picas de deposi??o em uma coluna de ?gua redox estratificada. As litof?cies intemperisadas apresentam diversas altera??es nos padr?es de ETR, anomalias de Ce e aus?ncia de anomalias de Y, causadas principalmente pela percola??o de fluidos. A mudan?a na composi??o isot?pica do ferro com profundidade ? mais complexa. Os valores mais negativos do SOF podem refletir a redu??o dissimilat?ria microbiana do Fe, e os valores positivos do SG podem estar relacionados ? oxida??o parcial do Fe2+ entre a fonte hidrotermal de ferro e os (hidr)?xidos de ferro. No entanto, quando interpretados em conjunto com dados mineral?gicos e de ETR, esses dados provavelmente registram os v?rios processos de altera??o que afetaram a Forma??o Ferr?fera Cau?. Tais achados ressaltam a import?ncia do acoplamento da an?lise sedimentol?gica com qu?mica elementar e isot?pica para entender a deposi??o da forma??o ferr?fera e processos de forma??o de min?rio de ferro.Iron formation is a Precambrian, Fe-rich, biochemical sedimentary rock that contains information about the composition of ancient seawater, the evolution of life, and the feedback processes that regulated the early Earth system. The continental margin (Superior-type) iron formation of the Cau? Formation, Iron Quadrangle, Brazil, comprises a laminated, magnetite-rich chemical meta-mudstone that was altered during hydrothermal circulation of basinal fluids, greenschist to amphibolite facies metamorphism, and subsequent supergene enrichment of Fe. The purpose of this work is to develop and implement methods for determination of trace elements, especially rare earth elements (REE), in itabirite samples, and to interpret the rare-earth elements plus yttrium (REE+Y) and ? 56Fe composition of continental margin iron formation from the Cau? Formation, in diagenetic, hydrothermal, and metamorphic context. The proposed method for trace elements analysis by ICP-MS after acid dissolution and the developed methodology for determination of REE by LA-ICP-MS show to be suitable for the intended use. Paragenesis-based lithogeochemical analyses of two drill cores with contrasting alteration styles highlight the importance of hydrothermal, metamorphic, and supergene processes on REE+Y and ?56Fe compositions of iron formation. The first core is from the Ouro Fino Syncline (OFS) and presents less altered lithofacies at the base, followed by others that have undergone hydrothermal and supergenic alteration. The second core comes from the Gandarela Syncline (SG) and has itabirites intensely altered by hydrothermal fluids, supergenic enrichment and weathering. The effect of supergene enrichment and weathering is best captured along the depth profile of each core by the inverse relationship between SiO2 and Fe2O3; SiO2 values are lowest and Fe2O3 values highest near the surface. The presence of goethite to 500 m records the maximum depth of these processes in the subsurface. The REE+Y, and Y anomalies from the deepest and least altered lithofacies in both cores are typical of deposition in a redox-stratified water column. The weathered lithofacies show several changes in the REE+Y patterns, Ce anomalies and absence of Y anomalies, caused mainly by fluid percolation. The change in Fe isotopic composition with depth is more complex. The most negative values from the OFS could reflect synsedimentary microbial dissimilatory Fe reduction, and the positive values from the GS may be related to partial Fe2+ oxidation between the hydrothermal Fe source and Fe-(oxyhydr)oxides. However, when interpreted together with mineralogical and REE+Y data, these data likely record the various alteration processes that affected the Cau? Iron Formation. Such findings highlight the importance of coupling sedimentologic analysis with elemental and isotopic chemistry to understand iron formation deposition and Fe ore-forming processes

High-affinity transport, cyanide-resistant respiration, and ethanol production under aerobiosis underlying efficient high glycerol consumption by Wickerhamomyces anomalus

Wickerhamomyces anomalus strain LBCM1105 was originally isolated from the wort of cachaça (the Brazilian fermented sugarcane juice-derived Brazilian spirit) and has been shown to grow exceptionally well at high amounts of glycerol. This paramount residue from the biodiesel industry is a promising cheap carbon source for yeast biotechnology. The assessment of the physiological traits underlying the W. anomalus glycerol consumption ability in opposition to Saccharomyces cerevisiae is presented. A new WaStl1 concentrative glycerol-H+ symporter with twice the affinity of S. cerevisiae was identified. As in this yeast, WaSTL1 is repressed by glucose and derepressed/induced by glycerol but much more highly expressed. Moreover, LBCM1105 aerobically growing on glycerol was found to produce ethanol, providing a redox escape to compensate the redox imbalance at the level of cyanide-resistant respiration (CRR) and glycerol 3P shuttle. This work is critical for understanding the utilization of glycerol by non-Saccharomyces yeasts being indispensable to consider their industrial application feeding on biodiesel residue.This work was supported by grants from Fundacao de Capacitacao de Pessoal de Nivel Superior from the Ministry of Education-CAPES/Brazil (PNPD 2755/2011; PCF-PVE 021/2012), from FEDER through POFC-COMPETE and by FCT through strategic funding (UID/BIA/04050/2013), from Universidade Federal de Ouro Preto, and a research fellowship from Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq (Brazil) Process 304815/2012 (research grant) and Process 305135/2015-5 (research fellowship to R.L.B.). C.L. is supported by the strategic program UID/BIA/04050/2013 [POCI-01-0145-FEDER-007569] funded by national funds through the FCT I. P. and by the ERDF through the COMPETE2020-Programa Operacional Competitividade e (POCI). The AUXPE-PVES 1801/2012 (Process 23038.015294/2016-18) from Brazilian Government supported a grant of Visiting Professor to C.L. and a research fellowships to A.C.C. and to F.F.O

Determination of trace elements in iron formation samples by ICP-MS and production of one quality control reference material

Orientador: Jacinta EnzweilerDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de GeociênciasResumo: As formações ferríferas são rochas sedimentares que foram depositadas essencialmente no Pré-cambriano. Durante este período, a Terra passou por diversas mudanças que afetaram os estilos de deposição dessas formações. A fração em massa de elementos-traço, especialmente os elementos terras raras (ETR), pode ser usada para o estudo da gênese dessas rochas e no entendimento da evolução atmosférica, da composição química dos oceanos e do aparecimento da vida na Terra. A determinação dos ETR em formações ferríferas apresenta algumas especificidades. As frações em massa desses elementos tendem a ser baixas, não há muitas informações disponíveis sobre métodos específicos para a dissolução das amostras e a ausência de materiais de referência (MR) com valores de ETR certificados dificulta a validação dos procedimentos analíticos. Procedimentos de dissolução que empregam quatro ácidos (HF, HNO3, HCl e HClO4), sem e com pressão (bomba), foram testados e aprimorados durante o estudo para aumentar sua eficiência quando aplicados a amostras de formações ferríferas. A dissolução após a sinterização com peróxido de sódio também foi empregada em algumas etapas do estudo. A determinação de 28 elementos-traço foi realizada por Espectrometria de Massas com Plasma Indutivamente Acoplado (ICP-MS) equipado com cela de colisão, empregando parâmetros instrumentais e de otimização do sinal adequados para realizar as medições dos elementos de interesse. A validação dos métodos foi realizada por comparação com valores publicados na literatura para os MR internacionais de formações ferríferase FER-1, FER-2, FER-3, FER-4 e IF-G. Os métodos de dissolução ácida apresentaram características de desempenho, como coeficiente de variação e limites de detecção, apropriados ao uso pretendido dos resultados. Os dados baseados no procedimento de digestão ácida na ausência de pressão apresentaram médias de fração em massa mais baixas que os da bomba para alguns elementos nos MR FER-3 e FER-4, indicando dissolução incompleta desses materiais naquelas condições. Os valores médios obtidos após a sinterização das amostras foram mais baixos do que os das digestões ácidas, mas o perfil dos ETR não se alterou de forma significativa. Após a validação dos métodos, um material de controle de qualidade (MCQ) da matriz foi preparado, a partir de uma amostra de itabirito friável proveniente do Quadrilátero Ferrífero (MG), escolhida dentre amostras previamente analisadas. Cerca de 6,5 kg da amostra foram pulverizados, homogeneizados e divididos em 64 potes, cada um com 100 g. O MCQ apresentou homogeneidade satisfatória, isto é, variância composicional estatisticamente insignificante em relação à variância dos resultados analíticos obtidos em condições de repetitividade. O MRC BRP-1 foi utilizado durante a caracterização do MCQ para assegurar a rastreabilidade metrológica do material produzidoAbstract: Iron formations are sedimentary rocks mostly deposited during the Precambrian. During that period, the Earth has passed through several changes that affected the types of deposition of these formations. The mass fraction of trace elements, especially the rare earth elements (REE), can be used to study the genesis of these rocks and to understand the atmospheric evolution, the chemical composition of oceans and the appearance of life on Earth. The determination of REE in such matrices shows some specificity. The mass fractions of these elements tend to be low, little information is available on specific methods for sample dissolution and the absence of reference materials (RM) with certified values of REE hinders proper validation of the analytical procedures. Methods of dissolution based on four acids (HF, HNO3, HCl and HClO4), with and without pressure (bomb), were tested and improved during the study to increase their efficiency when applied to iron formation samples. The dissolution of samples after sintering with sodium peroxide was also used in some steps of the study. The determination of twenty eight trace elements in iron formation samples was carried out by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) equipped with collision cell, using optimized signal conditions and instrumental parameters to measure the elements of interest. The methods validation was carried out by comparison with published values of the international iron formation RM FER-1, FER-2, FER-3, FER-4 and IF-G. The acid digestion methods showed performance characteristics, such relative standard deviation and detection limits, suitable for the intended use of the results. The results for some elements in RM FER-3 and FER-4 presented lower mean mass fractions for digestions perfomed without pressure, compared to those with pressure (bomb) indicating an incomplete dissolution in the first situation. The mean mass fractions obtained by the sintering procedure were lower than those of acid digestions, but the normalized patterns of REE did not change significantly. After method validation, a quality control reference material (QCM) was prepared from a sample of friable Itabirito, from Quadrilátero Ferrífero (MG), chosen among previously analyzed samples. About 6,5 kg from the sample was pulverized, homogenized and divided, resulting in sixty-four bottles of 100 g each. The QCM showed sufficient homogeneity, i.e. the compositional variance is statistically insignificant compared to the analytical variance, obtained under repeatability conditions. The certified reference material BRP-1 was used during the characterization of the QCM to ensure the metrological traceability to the results of the produced materialMestradoGeologia e Recursos NaturaisMestre em Geociência

New ICP-MS results for trace elements in five iron-formation reference materials

Iron formations (IFs) typically contain low mass fractions of most trace elements, including the rare earth elements (REE), and few publications describe analytical methods dedicated to this matrix. In this study, we used bomb and table-top acid dissolution procedures and ICP-MS to determine the mass fractions of trace elements in IF reference materials FER-1, FER-2, FER-3, FER-4 and IF-G. The full digestion of the IF samples with the bomb procedure required the addition of a small amount of water together with the acids. The results obtained by this method mostly agreed statistically with published values. The most remarkable exception was the higher values obtained for the heavy REE in FER-3. The recoveries of the REE obtained with the table-top procedure were slightly higher than those of the bomb digestion, except for the values of the heavy REE in FER-3 and FER-4, which were up to 30% lower than published values. Sintering of the samples with sodium peroxide was performed to determine the REE, but the results tended to be lower than those derived following acid digestion. On the whole, the recoveries showed dependence on the conditions of digestion, but subtle differences in trace mineral composition between samples also exerted influence on the analytical results for trace elements.Iron formations (IFs) typically contain low mass fractions of most trace elements, including the rare earth elements (REE), and few publications describe analytical methods dedicated to this matrix. 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ISS.), p. 158Govindaraju, K., Working values with confidence limits for twenty-six CRPG, ANRT and IWG-GIT geostandards (1995) Geostandards Newsletter, 19 (SPEC. ISS.), p. 32Guimette, C., Hébert, R., Wang, C., Villeneuve, M., Geochemistry and geochronology of the metamorphic sole underlying the Xigaze Ophiolite, Yarlung Zangbo Suture Zone, South Tibet (2009) Lithos, 112, pp. 149-162James, H.L., Sedimentary facies of iron-formation (1954) Economic Geology, 49, pp. 235-293Jarvis, K.E., A critical evaluation of two sample preparation techniques for low-level determination of some geologically compatible elements by ICP-MS (1990) Chemical Geology, 83, pp. 89-103Kamber, B.S., Bolhar, R., Webb, G.E., Geochemistry of late Archaean stromatolites from Zimbabwe: Evidence of microbial life restricted epicontinental seas (2004) Precambrian Research, 132, pp. 379-399Konhauser, K.O., Pecoits, E., Lalonde, S.V., Papineau, D., Nisbet, E.G., Barley, M.E., Arndt, N.T., Kamber, B.S., Oceanic nickel depletion and a methanogen famine before the Great Oxidation Event (2009) Nature, 458, pp. 750-753Kubicki, J.D., Sofo, J.O., Skelton, A.A., Bandura, A.V., A new hypothesis for the dissolution mechanism of silicates (2012) Journal of Physical Chemistry C, 116, pp. 17479-17491Linge, K.L., Jarvis, K.E., Quadrupole ICP-MS: Introduction to instrumentation, measurement techniques and analytical capabilities (2009) Geostandards and Geoanalytical Research, 33, pp. 445-467Lüttge, A., Arvidson, R.S., Fisher, C., A stochastic treatment of crystal dissolution kinetics (2013) Elements, 9, pp. 183-188Magnusson, B., Näykki, T., Hovind, H., Krysell, M., Handbook for calculation of measurement uncertainty in environmental laboratories (2012) Nordtest TR 537 edition 3.1, , http://www.nordtest.info, Accessed on 29 September 2013McLeod, C.R., Liang-guo, W., Abbey, S., Mineralogy and petrology of four "standard" samples of iron formation. Current research (1982) Geological Survey of Canada, Paper No. 82-1A, pp. 435-437Meisel, T., Schoner, N., Paliulionyte, V., Kahr, E., Determination of rare earth elements, Y, Th, Zr, Hf, Nb and Ta in geological reference materials G-2, G-3, SCo-1 and WGB-1 by sodium peroxide sintering and inductively coupled plasma-mass spectrometry (2002) Geostandards Newsletter: The Journal of Geostandards and Geoanalysis, 26, pp. 53-61Migdisov, A.A., Williams-Jones, A.E., Wagner, T., An experimental study of the solubility and speciation of the rare earth elements (III) in fluoride- and chloride-bearing aqueous solutions at temperatures up to 300 °C (2009) Geochimica et Cosmochimica Acta, 73, pp. 7087-7109Navarro, M.S., Andrade, S., Ulbrich, H., Gomes, C.B., Girardi, V.A.V., The direct determination of rare earth elements in basaltic and related rocks using ICP-MS: Testing the efficiency of microwave oven sample decomposition procedures (2008) Geostandards and Geoanalytical Research, 32, pp. 167-180Pecoits, E., Gingras, M.K., Barley, M.E., Kappler, A., Posth, N.R., Konhauser, K.O., Petrography and geochemistry of the Dales Gorge banded iron formation: Paragenetic sequence, source and implications for palaeo-ocean chemistry (2009) Precambrian Research, 172, pp. 163-187Planavsky, N., Bekker, A., Rouxel, O.J., Kamber, B., Hofmann, A., Knudsen, A., Lyons, T.W., Rare earth element and yttrium compositions of Archean and Paleoproterozoic Fe formations revised: New perspectives on the significance and mechanisms of deposition (2010) Geochimica et Cosmochimica Acta, 74, pp. 6387-6405Raut, N.M., Huang, L.S., Aggarwal, S.K., Lin, K.C., Determination of lanthanides in rock samples by inductively coupled plasma-mass spectrometry using thorium as oxide and hydroxide correction standard (2003) Spectrochimica Acta Part B, 58, pp. 809-822Robinson, P., Higgins, N.C., Jenner, G.A., Determination of rare-earth elements, yttrium and scandium in rocks by an ion exchange X-ray fluorescence technique (1986) Chemical Geology, 55, pp. 121-137Robinson, P., Townsend, A.T., Yu, Z., Münker, C., Determination of scandium, yttrium and rare earth elements in rocks by high resolution inductively coupled plasma-mass spectrometry (1999) Geostandards Newsletter: The Journal of Geostandards and Geoanalysis, 23, pp. 31-46Tanis, E.A., Simon, A., Tschauner, O., Chow, P., Xiao, Y., Shen, G., Hanchar, J., Krank, M., Solubility of xenotime in a 2 M HCl aqueous fluid from 1.2 to 2.4 GPa and 300 to 500 °C (2012) American Mineralogist, 97, pp. 1708-1713Towe, K.M., Aerobic carbon cycling and cerium oxidation: Significance for Archean oxygen levels and banded iron-formation deposition (1991) Palaeogeography, Palaeoclimatology, Palaeoecology (Global and Planetary Change Section), 97, pp. 113-123Uchino, T., Ebihara, M., Furuta, N., Determination of rare earth elements in Precambrian sediments at Isua by inductively coupled plasma-mass spectrometry (1995) Journal of Analytical Atomic Spectrometry, 10, pp. 25-30Yu, Z., Robinson, P., McGoldrick, P., An evaluation of methods for the chemical decomposition of geological materials for trace element determination using ICP-MS (2001) Geostandards Newsletter: The Journal of Geostandards and Geoanalysis, 25, pp. 199-217Zhang, W., Hu, Z., Liu, Y., Chen, H., Gao, S., Gaschnig, R.M., Total rock dissolution using ammonium bifluoride (NH4HF2) in screw-top Teflon vials: A new development in open-vessel digestion (2012) Analytical Chemistry, 84, pp. 10686-10693Scholarships from the National Council for Scientific andTechnological Development (CNPq) and financial supportthrough Grant 2003/09916-6, S~ao Paulo Research Foun-dation (FAPESP) are acknowledge

Sugar transport systems in Kluyveromyces marxianus CCT 7735.

The pattern of glucose repression in most Kluyveromyces marxianus strains does not correlate with fermentative behaviour; however, glucose repression and fermentative metabolism appear to be linked to the kinetics of sugar uptake. In this work, we show that lactose transport in K. marxianus CCT 7735 by lactose-grown cells is mediated by a low-affinity H+-sugar symporter. This system is glucose repressed and able to transport galactose with low affinity. We also observed the activity of a distinct lactose transporter in response to raffinose. Regarding glucose uptake, specificities of at least three low-affinity systems rely on the carbon source available in a given growth medium. Interestingly, it was observed only one high-affinity system is able to transport both glucose and galactose. We also showed that K. marxianus CCT 7735 regulates the expression of sugar transport systems in response to glucose availability

Caracterização geoquímica dos itabiritos silicoso, anfibolítico e magnetítico da região de Serra Azul - QF, MG.

Formações ferríferas são importantes fontes de informações sobre a evolução da hidrosfera, atmosfera, biosfera e litosfera da Terra. Esse trabalho reúne dados geoquí-micos de elementos maiores, menores e traços (incluindo os elementos terras raras) dos itabiritos silicoso, anfibolítico e magnetítico da Formação Cauê provenientes da região de Serra Azul (QF). Em se tratando das concentrações de elementos-traço, considerados traçadores de contaminação detrital, pode-se inferir que o tipo magnetítico é o que possui uma maior contaminação e que o silicoso, a menor. Embora existam diferenças no somatório total de ETR nos três diferentes tipos de itabiritos estudados, na região de Serra Azul, não foi possível verificar discrepân¬cias muito significativas no espectro de ETR dos três diferentes tipos estudados. São características comuns aos três tipos de itabiritos: i) anomalias positivas de Eu (Pla¬ navsky et al., 2010); ii) enriquecimento em ETR pesados em relação aos leves; iii) razões (Sm/Yb)SN<1 e (Eu/Sm)SN>1 (Bau & Möller, 1993). Os itabiritos magnetítico e o silicoso possuem ainda em comum anomalias positivas de Y, uma característica que aparece em algumas amostras do tipo anfibolítico também. As outras amostras de itabirito anfibolítico possuem anomalias negativas de Y.Banded iron formations are important providers of information about the evo¬lution of the hydrosphere, atmosphere, biosphere and lithosphere of the Earth. This study gathers data from the geochemical investigation of major, minor and trace el¬ements (including rare earth elements) of the siliceous, amphibolitic and magnetitic types of itabirite from the Cauê Formation, sampled in the Serra Azul region (Quadri¬látero Ferrífero). Observing the trace elements described as tracers of detrital contamination can be inferred that the magnetitic itabirite has the highest contamination and that the siliceous type has the lowest one. Although there are differences in the total sum of REE in the three itabirite types of Serra Azul, there are no discrepancies in the REE spectrum of each type. The itabirite types have as common characteristics in their REE spectrum: i) positive Eu anomalies (Planavsky et al., 2010); ii) HREE enrichment in relation to the LREE; iii) ratios of (Sm/Yb)SN<1 and (Eu/Sm)SN>1 (Bau & Möller, 1993). The magnetitic and the siliceous itabirites had positive Y anomalies, a common characteristic that appeared in some amphibolitic samples. On the other hand, the other amphibolitic samples had negative Y anomalies

Surgical complications in 2,840 cases of hemorrhoidectomy by Milligan-Morgan, Ferguson and combined techniques

The analysis of 2,840 cases of hemorrhoidectomy by open techniques of Milligan-Morgan (2,189 cases), Ferguson (341 cases) and mixed (310 cases) in 11,043 patients with hemorrhoidal disease (HD) allowed the following conclusions. The patients' acceptance of surgical indication for hemorrhoidectomy was 25.7%. Hemorrhoidectomy was more common among women (53.8%) than men (46.2%), and more accepted by women (26.5%) than men (24.8%). Hemorrhoidectomy was more common in patients of the fourth (27.7%), fifth (21.9%) and third (21.0%) decades of age. Most patients who agreed to undergo hemorrhoidectomy were those of the second (38.2%), eighth (35.9%) and ninth (34.5%) decades of age. The overall incidence of surgical complications was 3.0% (87 cases): anal stenosis (1.8%), bleeding (0.8%), worsening of anal hypotonia (0.2%), sepsis (0.1%) and systemic complications (0.1%), with no difference among the techniques used. The incidence of surgical complications by Milligan-Morgan technique was 3.0% - stenosis (1.9%), bleeding (1.9%), worsening of anal hypotonia (0.2%) and systemic complications (0.04%). The incidence of surgical complications by Ferguson's technique was 3.5% - stenosis (1.7%), bleeding (0.6%), worsening of anal hypotonia (0.6%) and sepsis (0.6%). And the incidence of surgical complications by mixed techniques was 2.5% - stenosis (1.0%), bleeding (0.3%), worsening of anal hypotonia (0.3%), sepsis (0.3%) and systemic complications (0.3%). The incidence of surgical complications according to gender was 3.0% among women and 3.2% among men, with higher incidence of stenosis in women (2.0%) and hemorrhage in men (1.1%). Surgical complications were more observed in the eighth (5.1%) and seventh (3.8%) decades of age. The incidence of anal stenosis was 1.8%, being 64.0% without hypotonia and 66.0% without anal fissure (66.0%), with annular stenosis as the most common anatomical shape (70.0%). Anal stenosis was more common among women (2.0%) presenting mean age of 38.2 years, with no relation to age decades. The most common technique for anal stenosis was single anotomy without sphincterotomy (46.0%). All cases of anal bleeding had surgical ligation of all hemorrhoidal pedicles, no matter if the bleeding site was found or not.<br>O seguimento de uma casuística de 2.840 hemorroidectomias pelas técnicas de Milligan-Morgan (2.189 casos), Ferguson (341 casos) e mista (310 casos) em 11.043 pacientes portadores de doença hemorroidária (DH) permitiu as seguintes conclusões. A aceitação da indicação cirúrgica para doença hemorroidária (DH), pelos pacientes, foi de 25,7%. A doença hemorroidária (DH) foi mais comum entre mulheres (53,8%) que em homens (46,2%) e a hemorroidectomia foi mais aceita pelas mulheres (26,5%) que pelos homens (24,8%). A hemorroidectomia foi mais realizada em pacientes de quarta (27,7%), quinta (21,9%) e terceira (21,0%) décadas etárias. Os pacientes que mais aceitaram a indicação cirúrgica foram os da segunda (38,2%), oitava (35,9%) e nona (34,5%) décadas etárias. A incidência global de complicações cirúrgicas foi de 3,0% (87 casos): estenose anal (1,8%), hemorragia grave (0,8%), agravamento da hipotonia anal (0,2%), sepse (0,1%) e sistêmicas (0,1%), sem diferença entre as técnicas usadas. A incidência de complicações cirúrgicas pela técnica de Milligan-Morgan foi de 3,0%: estenose (1,9%), hemorragia grave (1,9%), agravamento da hipotonia anal (0,2%) e sistêmicas (0,04%). A incidência de complicações cirúrgicas pela técnica de Ferguson foi de 3,5%: estenose (1,7%), hemorragia grave (0,6%), agravamento da hipotonia anal (0,6%) e sepse (0,6%). A incidência de complicações cirúrgicas pela técnica mista foi de 2,5%: estenose (1,0%), hemorragia grave (0,3%), agravamento da hipotonia anal (0,3%), sepse (0,3%) e sistêmicas (0,3%). A incidência de complicações cirúrgicas pelos gêneros foi de 3,0% entre as mulheres e 3,2% entre os homens, com maior incidência de estenose nas mulheres (2,0%) e hemorragia nos homens (1,1%). As décadas em que mais ocorreram complicações foram a oitava (5,1%) e a sétima (3,8%). A incidência de estenose anal foi de 1,8%, prevalecendo sem hipertonia anal (64,0%) e com fissura anal (66,0%), sendo a forma anatômica mais comum a anular (70,0%); foi mais comum entre mulheres (2,0%) com idade média de 38,2 anos, sem relação com as décadas etárias. A cirurgia corretiva da estenose anal mais usada foi a anotomia simples ou com fissurectomia sem esfincterotomia (46,0%). Em todos os casos de hemorragia anal cirúrgica foi feita ligadura de todos os pedículos da ressecção hemorroidária, independentemente de se encontrar ou não o local da hemorragia

Determination of rare earth elements in Fe-minerals using external calibration by LA-ICP-MS and application on Cau? Iron Formation (Brazil).

The rare earth elements (REE) composition in Fe-mineral phases is an important tool in iron formation studies to obtain information about parent rocks and environmental and paragenetic processes. However, the determination of REE presents some difficulties, such as the low concentration of these elements, matrix complexity and lack of iron matrix certified reference materials. The aim of the present work is to propose an analytical method to determine the REE plus Y (REE + Y) contents at trace levels in Fe-(hydr)oxides by the laser ablation ICPquadrupoleMS technique, using external calibration. The calibration curves were obtained from analyses of reference materials with different matrices, and the analytical conditions were checked on the NIST 614 glass. The linearity (R2 ? 0.98), limit of detection (0.002?0.044 ?g g?1), limit of quantification (0.008?0.146 ?g g?1), recovery (88.4?112.4%), and intraday (0.1?14.1%) and interday (1.6?17.8%) precision were systematically assessed. The results obtained showed that the method is fit for the purpose and showed evidence of a nonsignificant interference of the matrix. Thus, the developed procedure was applied in the analyses of magnetite, martite, hematite, and goethite grains from Cau? Iron Formation (Brazil). The REE + Y patterns of the minerals are consistent with the previous study of bulk analyses on whole rocks and highlight the postdepositional signature of these elements in banded iron formations

High?affinity transport, cyanide?resistant respiration, and ethanol production under aerobiosis underlying efficient high glycerol consumption by Wickerhamomyces anomalus.

Wickerhamomyces anomalus strain LBCM1105 was originally isolated from the wort of cacha?a (the Brazilian fermented sugarcane juice-derived Brazilian spirit) and has been shown to grow exceptionally well at high amounts of glycerol. This paramount residue from the biodiesel industry is a promising cheap carbon source for yeast biotechnology. The assessment of the physiological traits underlying the W. anomalus glycerol consumption ability in opposition to Saccharomyces cerevisiae is presented. A new WaStl1 concentrative glycerol-H+ symporter with twice the affinity of S. cerevisiae was identified. As in this yeast, WaSTL1 is repressed by glucose and derepressed/induced by glycerol but much more highly expressed. Moreover, LBCM1105 aerobically growing on glycerol was found to produce ethanol, providing a redox escape to compensate the redox imbalance at the level of cyanide-resistant respiration (CRR) and glycerol 3P shuttle. This work is critical for understanding the utilization of glycerol by non-Saccharomyces yeasts being indispensable to consider their industrial application feeding on biodiesel residue