Rol y habilidades del CIO. Tres casos de estudio en Colombia: Alpina, Banco de Bogotá, Grupo Aval

Con base en la revisión de la literatura realizada acerca de los roles directivos y del rol de uno en particular que es el CIO, y tomando como referencia la información suministrada por los directivos de tecnologías de Información de las organizaciones Alpina, Banco de Bogotá y Grupo AVAL, el trabajo de investigación hace una descripción del contenido del rol de CIO e identifica las habilidades requeridas para el ejercicio de este rol en dichas organizaciones. Se espera que los resultados del presente estudio generen un valioso aporte como retroalimentación para la academia y las empresas acerca de la formación de los futuros CIO.

Asma ocupacional en peluquería: una revisión de la literatura

Este artículo pretende realizar una revisión de la literatura vigente acerca del asma ocupacional secundaria a la exposición de los factores de riesgo identificados en peluquería. Se realizó una búsqueda sistemática en las bases de datos PubMed y Cochrane de artículos de revistas indexadas con las palabras claves “Asthma occupational, hairdressers, hairdresser, work related asthma”. Aplicando los criterios de selección descritos, se revisaron 26 artículos en total donde se incluían reportes de casos, estudios de prevalencia, incidencia, corte transversa y revisiones, abarcando principalmente los temas de epidemiologia, fisiopatología, diagnóstico y prevención. Se agruparon según la metodología PRISMA para su respectiva comparación. Se concluyó que a pesar de la importancia de esta patología en el sector de peluquería, existen factores asociados como la informalidad del sector, la falta de estudios de investigación originales de cohorte o el desconocimiento de un protocolo claro de diagnóstico en este tipo de trabajadores, que limitan datos concluyentes acerca de la misma. Sin embargo, la mayoría de los autores concluye la relación entre la patología y la labor de peluquería, así falte esclarecer los mecanismos fisiopatológicos relacionados con los alérgenos identificados.

Fatiga del reanimador y calidad de las compresiones torácicas en niños con y sin vía aérea asegurada

Introducción: La calidad de las compresiones torácicas tiene importancia durante la reanimación pediátrica y se ve afectada por diversos factores como la fatiga del reanimador, esta puede verse condicionada por las características de las compresiones establecidas según la presencia o ausencia de un dispositivo avanzado en la vía aérea determinando la interrupción continuidad de las mismas. En este estudio se realizó una simulación clínica, evaluando la presencia de fatiga del reanimador frente a pacientes con y sin dispositivo avanzado de la vía aérea. Metodología: Se incluyeron 12 participantes, quienes realizaron compresiones torácicas a un simulador clínico, tanto para el caso de la maniobra 1 correspondiente a ciclos interrumpidos con el fin de proporcionar ventilaciones, como para el caso de la maniobra 2 en la que la actividad fue continua. Se midieron calidad de compresiones, VO2 max y fatiga mediante escala de Borg RPE 6-20. Resultados: La calidad de las compresiones disminuyó en ambos grupos después del minuto 2 y más rápidamente cuando fueron ininterrumpidas. La fatiga se incrementó cuando las compresiones fueron continuas. Discusión: Se evidencia una relación directamente proporcional del aumento de la fatiga en relación al tiempo de reanimación e inversamente proporcional entre la calidad de las compresiones y la sensación de cansancio, en especial después del minuto 2. Un tiempo de 2 minutos podría ser el tiempo ideal para lograr compresiones de calidad y para realizar el reemplazo de la persona que realiza las compresiones.

Serie de documentos. Facultad de Jurisprudencia N° 72. Aspectos prácticos del proceso ante el Centro Internacional de Arreglo de Diferencias relativas a Inversiones (CIADI)

Los TBI (Tratado Bilateral de Inversión) o también denominado los APPI (Acuerdo de Protección y Promoción de las Inversiones) son acuerdos que buscan la Protección y la Promoción de las inversiones que hagan los nacionales de un Estado en otro Estado conocido como el “Estado Receptor”. Los TBI y APPI fueron concebidos dentro del proceso de descolonización que le siguió a la Segunda Guerra Mundial. Esto se debe a que los Estados que habían colonizado otros territorios, ahora Estados soberanos y sus nacionales, seguían teniendo fuertes lazos e intereses económicos. Con el ánimo de protegerse de posibles expropiaciones, los Estados europeos liderados por Alemania, firmaron un número importante de TBI y APPI, no solamente con sus antiguas colonias, sino con otras. De esta manera, Alemania, Suiza, Holanda, Italia, Bélgica y Suecia suscribieron al menos cuarenta tratados de este tipo con varios Estados asiáticos, africanos y del medio oriente entre 1959 y 1965. Estados Unidos se demoró unos veinte o treinta años más, porque los estadounidenses no solamente aspiraban a obtener protección para sus inversionistas, sino que además solicitaban que se abriera y liberara la economía de los Estados firmantes. Finalmente, fue en la administración de Ronald Reagan que los Estados Unidos comenzó a suscribirlos.

Geographical variation in the clouded leopard, Neofelis nebulosa, reveals two species

The clouded leopard, Neofelis nebulosa, is an endangered semiarboreal felid with a wide distribution in tropical forests of southern and southeast Asia, including the islands of Sumatra and Borneo in the Indonesian archipelago [1]. In common with many larger animal species, it displays morphological variation within its wide geographical range and is currently regarded as comprising of up to four subspecies [2-4]. It is widely recognized that taxonomic designation has a major impact on conservation planning and action [5-8]. Given that the last taxonomic revision was made over 50 years ago [2], a more detailed examination of geographical variation is needed. We describe here the results of a morphometric analysis of the pelages of 57 clouded leopards sampled throughout the species' range. We conclude that there are two distinct morphological groups, which differ primarily in the size of their cloud markings. These results are supported by a recent genetic analysis [9]. On that basis, we give diagnoses for the distinction of two species, one in mainland Asia (N. nebulosa) and the other in Indonesia (N. diardi). The implications for conservation that arise from this new taxonomic arrangement are discussed.

Syntheses, conformations, and basicities of bicyclic triamines

The multistep syntheses of several bicyclic triamines are described, all of which have an imbedded 1,5,9-triazacyclododecane ring. In 1,5,9-triazabicyclo[7.3.3]pentadecanes 12, 13, 15, and 16, two nitrogens are bridged by three carbons. The monoprotonated forms of these triamines are highly stabilized by a hydrogen-bonded network involving the bridge and both bridgehead nitrogens, producing a difference of more than 8 pK(a) units in acidities of their monoprotonated and diprotonated forms. The one- and zero-carbon bridges in 1,5,9-triazabicyclo[9.1.1]tridecane (23) and 7-methyl-1,5,9-triazabicyclo[5.5.0]dodecane (39) do not enhance the stabilities of their monoprotonated forms. X-ray crystal structures and computational studies of 12.HI and 16.HI reveal similar, but somewhat weaker, hydrogen-bonded networks, relative to 15.HI. The activation free energies for conformational inversion of 13.HI (14.4 +/- 0.2 kcal/mol), 16.HI (15.0 +/- 0.1 kcal/mol) and 16 (8.8 +/- 0.3 kcal/mol) were measured by variable-temperature H-1 and C-13 NMR spectroscopy. These experimental barriers give an estimate of 6.2 kcal/mol for the strength of the bifurcated hydrogen bond between the bridge nitrogen and cavity proton in 16.HI. Computational studies support the hypothesis that N-inversion occurs in an open conformation, leading to an estimate of 10.32 kcal/mol for the enthalpy of the bifurcated hydrogen bond in 16.HI in the gas phase.

A temperature-dependent relative-rate study of the OH initiated oxidation of n-butane: the kinetics of the reactions of the 1-and 2-butoxy radicals

The kinetics of the reactions of 1-and 2-butoxy radicals have been studied using a slow-flow photochemical reactor with GC-FID detection of reactants and products. Branching ratios between decomposition, CH3CH(O-.)CH2CH3 CH3CHO + C2H5, reaction (7), and reaction with oxygen, CH3CH(O-.)CH2CH3 + O-2 -> CH3C(O)C2H5 + HO2, reaction (6), for the 2-butoxy radical and between isomerization, CH3CH2CH2CH2O. -> CH2CH2CH2CH2OH, reaction (9), and reaction with oxygen, CH3CH2CH2CH2O. + O-2 -> C3H7CHO + HO2, reaction (8), for the 1-butoxy radical were measured as a function of oxygen concentration at atmospheric pressure over the temperature range 250-318 K. Evidence for the formation of a small fraction of chemically activated alkoxy radicals generated from the photolysis of alkyl nitrite precursors and from the exothermic reaction of 2-butyl peroxy radicals with NO was observed. The temperature dependence of the rate constant ratios for a thermalized system is given by k(7)/k(6) = 5.4 x 1026 exp[(-47.4 +/- 2.8 kJ mol(-1))/RT] molecule cm(-3) and k(9)/k(8) = 1.98 x 10(23) exp[(-22.6 +/- 3.9 kJ mol(-1))/RT] molecule cm(-3). The results agree well with the available experimental literature data at ambient temperature but the temperature dependence of the rate constant ratios is weaker than in current recommendations.

Meta-analysis of relationships between enteric methane yield and milk fatty acid profile in dairy cattle

Various studies have indicated a relationship between enteric methane (CH4) production and milk fatty acid (FA) profiles of dairy cattle. However, the number of studies investigating such a relationship is limited and the direct relationships reported are mainly obtained by variation in CH4 production and milk FA concentration induced by dietary lipid supplements. The aim of this study was to perform a meta-analysis to quantify relationships between CH4 yield (per unit of feed and unit of milk) and milk FA profile in dairy cattle and to develop equations to predict CH4 yield based on milk FA profile of cows fed a wide variety of diets. Data from 8 experiments encompassing 30 different dietary treatments and 146 observations were included. Yield of CH4 measured in these experiments was 21.5 ± 2.46 g/kg of dry matter intake (DMI) and 13.9 ± 2.30 g/ kg of fat- and protein-corrected milk (FPCM). Correlation coefficients were chosen as effect size of the relationship between CH4 yield and individual milk FA concentration (g/100 g of FA). Average true correlation coefficients were estimated by a random-effects model. Milk FA concentrations of C6:0, C8:0, C10:0, C16:0, and C16:0-iso were significantly or tended to be positively related to CH4 yield per unit of feed. Concentrations of trans-6+7+8+9 C18:1, trans-10+11 C18:1, cis- 11 C18:1, cis-12 C18:1, cis-13 C18:1, trans-16+cis-14 C18:1, and cis-9,12 C18:2 in milk fat were significantly or tended to be negatively related to CH4 yield per unit of feed. Milk FA concentrations of C10:0, C12:0, C14:0-iso, C14:0, cis-9 C14:1, C15:0, and C16:0 were significantly or tended to be positively related to CH4 yield per unit of milk. Concentrations of C4:0, C18:0, trans-10+11 C18:1, cis-9 C18:1, cis-11 C18:1, and cis- 9,12 C18:2 in milk fat were significantly or tended to be negatively related to CH4 yield per unit of milk. Mixed model multiple regression and a stepwise selection procedure of milk FA based on the Bayesian information criterion to predict CH4 yield with milk FA as input (g/100 g of FA) resulted in the following prediction equations: CH4 (g/kg of DMI) = 23.39 + 9.74 × C16:0- iso – 1.06 × trans-10+11 C18:1 – 1.75 × cis-9,12 C18:2 (R2 = 0.54), and CH4 (g/kg of FPCM) = 21.13 – 1.38 × C4:0 + 8.53 × C16:0-iso – 0.22 × cis-9 C18:1 – 0.59 × trans-10+11 C18:1 (R2 = 0.47). This indicated that milk FA profile has a moderate potential for predicting CH4 yield per unit of feed and a slightly lower potential for predicting CH4 yield per unit of milk. Key words: methane , milk fatty acid profile , metaanalysis , dairy cattle

Fatores associados ao controle metabólico em pacientes com diabetes melito tipo 2 não usuários de insulina

Introdução: a obtenção de um bom controle metabólico é essencial para a prevenção das complicações crônicas do Diabetes Melito (DM). O tratamento é complexo e depende da implementação efetiva das diferentes estratégias terapêuticas disponíveis. Para que isso seja possível, é necessário que o paciente entenda os princípios terapêuticos e consiga executá-los. A precária educação em diabetes é percebida como um dos obstáculos para o alcance das metas terapêuticas. Objetivo: analisar, os fatores associados ao controle metabólico, em pacientes com DM tipo 2 (DM2) não usuários de insulina. Métodos: foi realizado um estudo transversal em pacientes com DM2 não usuários de insulina, selecionados ao acaso entre aqueles que consultavam nos ambulatórios de Medicina Interna, Endocrinologia e Enfermagem do Hospital de Clínicas de Porto Alegre. Os pacientes foram submetidos à avaliação clínica, laboratorial e responderam um questionário que incluía o tipo de tratamento realizado para DM, outros medicamentos e co-morbidades, pesquisa de complicações em ano prévio e avaliação do conhecimento sobre DM. Os pacientes foram classificados em dois grupos, com bom ou mau controle glicêmico, de acordo com o valor da glico-hemoglobina de 1 ponto % acima do limite superior do método utilizado. As comparações entre variáveis contínuas, com distribuição normal, foram analisadas pelo teste t de Student para amostras não-pareadas e para as variáveis de distribuição assimétrica ou com variância heterogênea o teste U de Mann-Whitney. A comparação entre percentagem foi feita pelo teste de qui-quadrado ou exato de Fisher. Foi realizada uma análise logística múltipla para identificar os fatores mais relevantes associados ao controle metabólico (variável dependente). As variáveis independentes com um nível de significância de P < 0,1 na análise bivariada, foram incluídas no modelo. Resultados: foram avaliados 143 pacientes com DM2, idade de 59,3 ± 10,1 anos, duração conhecida do DM 7,5 ± 6,3 anos, índice de massa corporal (IMC) de 29,7 ± 5,2 kg/m².Destes, 94 pacientes (65,73%) apresentavam bom controle glicêmico. Os pacientes com mau controle glicêmico usavam mais anti-hiperglicemiantes orais como monoterapia (OR = 9,37; IC = 2,60-33,81; P=0,004) ou associados (OR = 31,08; IC = 7,42-130,15; P < 0,001). Da mesma maneira, não fizeram dieta em dias de festa (OR = 3,29; IC = 1,51-7,16; P = 0,012). A inclusão do conhecimento sobre diabetes não foi diferente entre os pacientes com bom ou mau controle glicêmico (OR = 1,08; IC = 0,97 - 1,21; P = 0,219). A análise multivariada demonstrou que a consulta com a enfermeira educadora (OR = 0,24; IC = 0,108-0,534; P = 0,003), com o endocrinologista (OR = 0,15 ; IC = 0,063-0,373; P = 0,001) e o uso de hipolipemiantes (OR = 0,10; IC = 0,016 - 0,72; P = 0,054) foram associados ao bom controle glicêmico, ajustados para a não realização de dieta em festas, uso de anti-hiperglicemiantes orais e conhecimento sobre diabetes. Conclusão: o controle metabólico em pacientes DM2 é influenciado pelas atividades de educação com enfermeira e endocrinologista. O tratamento do DM2 deve incluir atividades de educação de forma sistemática.

Efeitos da aplicação transendocárdica do laser de hólmio em pacientes com angina refratária

Objetivo - Investigar os efeitos da aplicação endocárdica do laser de hólmio em regiões isquêmicas de pacientes com angina refratária, sobre a classe funcional de angina, a tolerância ao esforço, o duplo produto, a fração de ejeção e o consumo de antianginosos. Métodos - Treze pacientes (66.10 ±12 anos) não elegíveis para angioplastia ou cirurgia, com angina refratária classe III-IV e fração de ejeção de 43,4±7,8% foram submetidos a 30-40 perfurações endocárdicas de 5 mm de profundidade com o laser de hólmio, aplicado pela via percutânea a regiões isquêmicas determinadas pela prova do Tálio 201. Cinco variáveis clínicas foram avaliadas aos 3, 6 e 12 meses. A significância estatística aos 3, 6 e 12 meses foi avaliada pelo ANOVA e pelo método proposto por Bonferroni. Resultados - Todos os procedimentos tiveram sucesso. A classe funcional de angina de base, aos 3, 6 e 12 meses era respectivamente: 3,5±0,5; 2,2±0,4; 1,7±0,5; 2,0±0,7 (P<0,001); a prova submáxima de Naughton (segundos) 374±133 (base); 518±121 (6 meses) [P=0,05]; 428±132 (12 meses) [P=0,029]; os antianginosos (mg/dia) 204,8±72,5; 204,8±72,5; 137,9±66,1; 121,7±32,7[P= 0,01]; a fração de ejeção (%) 43,4±7,8 (base); 49,0±6,9 (6 meses) [0,081] e o duplo produto (x 1000) 16,2±3,4 (base); 17,8±4,4 (6 meses); 17,5±4,4 (12 meses) [P=0,253]. Conclusão - Os dados sugerem que, no grupo estudado, a aplicação percutânea do laser de hólmio em regiões isquêmicas melhora de forma significativa a classe funcional de angina e a tolerância ao esforço, apesar da redução da medicação antianginosa.

Influence of food restriction on the reproduction and larval performance of matrinxã, Brycon amazonicus (Spix and Agassiz, 1829)

Este estudo avaliou o efeito da restrição alimentar e realimentação na reprodução de fêmeas e no crescimento inicial e sobrevivência de larvas de matrinxã, Brycon amazonicus. Matrizes distribuídas em 8 viveiros (15 peixes/tanque) foram alimentadas diariamente (em 4 tanques - G1) e alimentados em ciclos de 3 dias de alimentação seguidos de 2 dias de restrição (em 4 tanques - G2) por 6 meses antes da desova. Na indução à desova, 57% das fêmeas no G1 e 45% no G2 desovaram. Os pesos médios dos oócitos foram 208,1 g (G1) e 131,6 g (G2), sendo os oócitos G2 menores (1,017 ± 0,003 mm) que os oócitos de G1 (1,048 ± 0,002 mm). As taxas de fertilização (71,9 ± 12,6% e 61,2 ± 13,7%) e de eclosão (61,3 ± 33,9% e 67,5 ± 23,4%) entre os G1 e G2 não diferiram. Larvas foram coletadas na eclosão e às 24, 48 e 72 horas de incubação para medida do crescimento e as restantes transferidas para aquários e amostradas 1, 5, 9 e 15 dias depois. Na transferência, as larvas G1 e G2 tinham pesos similares (1,5 ± 0,15 e 1,46 ± 0,07 mg), mas o comprimento das larvas G2 era maior (6,2 ± 0,13 e 6,7 ± 0,14 mm). Ao 9° dia, quando é recomendada a transferência dos juvenis para tanques externos, os juvenis G2 tinham peso (13,6 ± 0,26 e 18,9 ± 0,07 mg) e comprimento (11,8 ± 0,09 e 14,5 ± 0,04 mm) maiores, mas no 15º dia os juvenis G1 eram maiores em peso (90,2 ± 1,19 e 68,6 ± 0,77 mg) e comprimento (18,8 ± 0,16 e 18,5 ± 0,04 mm). Aos 15 dias, a prole das fêmeas submetidas à restrição alimentar apresentou sobrevivência mais alta que a prole das fêmeas alimentadas diariamente (24,7 ± 2,07% e 19,2 ± 1,91%). A restrição alimentar imposta às fêmeas de matrinxã, apesar de reduzir o número de fêmeas que desovaram e a quantidade de oócitos extrusados, não afetou a fertilização e eclosão das larvas e melhorou a sobrevivência final das larvas.

Caracterização molecular e laboratorial da talassemia beta e da interação hemoglobina s/talassemia beta

Beta thalassemia arises as a consequence of the reduction (β+, β++, βsilent) or absence (β0) of beta globin chain synthesis and results from a number of mechanisms that lead to genetic defects. The inheritance of beta thalassemia is characterized by the existence of heterozygous individuals, compound heterozygotes, homozygotes and those with coinheritance of beta thalassemia allele and other thalassemias and/or hemoglobin variants. The aim of this study was to perform molecular and laboratory characterization of beta thalassemia in heterozygous and homozygous individuals and in those with coinheritance of S beta thalassemia. A total of 48 individuals were included (35 heterozygotes, 4 homozygotes and 9 S beta thalessemia carriers) referred to the Integrated Laboratory of Clinical Analyses of the Federal University of Rio Grande do Norte (UFRN) and the Hematology Ambulatory Facility of the Dalton Barbosa Cunha Hemocenter (Hemonorte Natal, Brazil). Peripheral blood samples form each patient underwent the following laboratory examinations: erythrogram, hemoglobin electrophoresis at alkaline pH, measurements of Hb A2, Fetal Hb and serum ferritin. DNA was extracted using the illustra blood genomicPrep Mini Spin Kit and molecular characterization was performed by the PCR/RFLP technique, which involves digestion with specific restriction enzymes for IVS-1 nt 1 (G®A), IVS-1 nt 6 (T®C) and codon 39 (CAG®TAG) mutations. Of the 35 heterozygotes, 37.1% showed IVS-1 nt 6 mutation, 42.9% IVS-1 nt 1 and 20% were carriers of other mutations not identified by the technique used. The four homozygous patients presented with the IVS-1 nt 6 mutation, while 66.7% of the individuals with S beta thalassemia had the IVS-1 nt 1 mutation. Codon 39 was not detected in any of the patients investigated. Of the thallasemic alleles found, 40.4% were IVS- 1 nt 1, 40.4% IVS-1 nt 6 and 19.2% were not identified. Laboratory data showed that the heterozygotes exhibited microcytosis and hypochromia, evidenced by MCV ranging from 57 to 75fL and MCH from 15.9 to 23.6 pg. Hemoglobin A2 varied between 3.7 and 7.2%. The homogygotes also showed reduced MCV and MCH and elevated HbA2.. Comparison of laboratory data between heterozygous individuals with IVS-1 nt 1 and IVS-1 nt 6 mutations showed that heterozygotes for the IVS1-1 mutation had significantly lower mean MCV and MCH (p = 0.023 and 0.007, respectively) and significantly higher hemoglobin A2 (p < 0.001) when compared to heterozygotes for the IVS-1 nt 6 mutation. PCR/RFLP was useful in identifying the presence or absence of IVS-1 nt 6, IVS-1 nt 1 and codon 39 mutations in most of the patients investigated here. This is the first study conducted in the state of Rio Grande do Norte, Brazil aimed at identifying beta thalassemia mutations and represents an important contribution to the knowledge regarding the molecular profile of beta thalassemia in our country

Activation and early parthenogenesis of bovine oocytes treated with ethanol and strontium

Efficient artificial activation is indispensable for the success of cloning programs. Strontium has been shown to effectively activate mouse oocytes for nuclear transfer procedures, however, there is limited information on its use for bovine oocytes. The present study had as objectives: (1) to assess the ability of strontium to induce activation and parthenogenetic development in bovine oocytes of different maturational ages in comparison with ethanol; and (2) to verify whether the combination of both treatments improves activation and parthenogenetic development rates. Bovine oocytes were in vitro matured for 24, 26, 28, and 30 h, and treated with ethanol (E, 7% for 5 min) or strontium chloride (S, 10 mM SrCl2 for 5 h) alone or in combination: ethanol + strontium (ES) and strontium + ethanol (SE). Activated oocytes were cultured in vitro in synthetic oviductal fluid (SOF) medium and assessed for pronuclear formation (15-16 h), cleavage (46-48 h) and development to the blastocyst stage (M). Treatment with ethanol and strontium promoted similar results regarding pronuclear formation (E, 20-66.7%; S, 26.7-53.3%; P > 0.05) and cleavage (E, 12.8-40.6%; S, 16.1-41.9%; P > 0.05), regardless of oocyte age. The actions of both strontium and ethanol were influenced by oocyte age: ethanol induced greater activation rates after 28 and 30 h of maturation (48.4 and 66.7% versus 20.0 and 23.3% for 24 and 26 It, respectively; P < 0.05) and strontium after 30 It (53.3%) was superior to 24 and 26h (26.7% for both). Blastocyst development rates were minimal in all treatments (0.0-6.3%; P > 0.05), however, when the mean (+/-S.D.) cell number in blastocysts at the same maturational period was compared, strontium treatment was superior to ethanol for activation rates (82 +/- 5.7 and 89.5 +/- 7.8 versus 54 and 61, at 28 and 30 h, respectively). Improved results were obtained by combined treatments. The combination of ethanol and strontium resulted in similar pronuclear formation (ES, 36.7-83.9%; SE, 53.1-90.3%) and cleavage rates (ES, 31.3-81.3%; SE, 65.6-80.7%). Regarding embryo development, there was no difference (P > 0.05) between treatments, and blastocysts were only obtained in treatment SE at 24 and 26 h (6.5% for both). It is concluded that, SrCl2 induces activation and parthenogenetic development in bovine oocytes. (C) 2003 Elsevier B.V. All rights reserved.

Lima beans production and economic revenue as function of organic and mineral fertilization

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Recuperação e purificação de proteínas do soro de queijo tipo coalho usando cromatografia de troca iônica e interação hidrofóbica em leito na forma expandida

Expanded Bed Adsorption plays an important role in the downstream processing mainly for reducing costs as well as steps besides could handling cells homogenates or fermentation broth. In this work Expanded Bed Adsorption was used to recover and purify whey proteins from coalho cheese manufacture using Streamline DEAE and Streamline SP both ionic resins as well as a hydrophobic resin Streamline Phenyl. A column of 2.6 cm inner diameter with 30 cm in height was coupled to a peristaltic pump. Hydrodynamics study was carried out with the three resins using Tris-HCl buffer in concentration of 30, 50 and 70 mM, with pH ranging from 7.0 to 8.0. In this case, assays of the expansion degree as well as Residence Time Distribution (RTD) were carried out. For the recovery and purification steps, a whey sample of 200 mL, was submitted to a column with 25mL of resin previously equilibrated with Tris/HCl (50 mM, pH 7.0) using a expanded bed. After washing, elution was carried out according the technique used. For ionic adsorption elution was carried out using 100 mL of Tris/HCl (50 mM, pH 7.0 in 1M NaCl). For Hydrophobyc interaction elution was carried out using Tris/HCl (50 mM, pH 7.0). Adsorption runs were carried out using the three resins as well as theirs combination. Results showed that for hydrodynamics studies a linear fit was observed for the three resins with a correlation coefficient (R2) about 0.9. In this case, Streamline Phenyl showed highest expansion degree reaching an expansion degree (H0/H) of 2.2. Bed porosity was of 0.7 when both resins Streamline DEAE and Streamline SP were used with StremLine Phenyl showing the highest bed porosity about 0.75. The number of theorical plates were 109, 41.5 and 17.8 and the axial dipersion coefficient (Daxial) were 0.5, 1.4 and 3.7 x 10-6 m2/s, for Streamline DEAE, Streamline SP and Streamline Phenyl, respectively. Whey proteins were adsorved fastly for the three resins with equilibrium reached in 10 minutes. Breakthrough curves showed that most of proteins stays in flowthrough as well as washing steps with 84, 77 and 96%, for Streamline DEAE, Streamline SP and Streamline Phenyl, respectively. It was observed protein peaks during elution for the three resins used. According to these peaks were identified 6 protein bands that could probably be albumin (69 KDa), lactoferrin (76 KDa), lactoperoxidase (89 KDa), β-lactoglobulin (18,3 KDa) e α-lactoalbumin (14 KDa), as well as the dimer of beta-lactoglobulin. The combined system compound for the elution of Streamline DEAE applied to the Streamline SP showed the best purification of whey proteins, mainly of the α-lactoalbumina