Cloning, Expression, Characterization and Immobilization of a Recombinant Carboxylesterase from the Halophilic Archaeon, Halobacterium salinarum NCR-1.

Only a few halophilic archaea producing carboxylesterases have been reported. The limited research on biocatalytic characteristics of archaeal esterases is primarily due to their very low production in native organisms. A gene encoding carboxylesterase from Halobacterium salinarum NRC-1 was cloned and successfully expressed in Haloferax volcanii. The recombinant carboxylesterase (rHsEst) was purified by affinity chromatography with a yield of 81%, and its molecular weight was estimated by SDS-PAGE (33 kDa). The best kinetic parameters of rHsEst were achieved using p-nitrophenyl valerate as substrate (KM = 78 µM, kcat = 0.67 s-1). rHsEst exhibited great stability to most metal ions tested and some solvents (diethyl ether, n-hexane, n-heptane). Purified rHsEst was effectively immobilized using Celite 545. Esterase activities of rHsEst were confirmed by substrate specificity studies. The presence of a serine residue in rHsEst active site was revealed through inhibition with PMSF. The pH for optimal activity of free rHsEst was 8, while for immobilized rHsEst, maximal activity was at a pH range between 8 to 10. Immobilization of rHsEst increased its thermostability, halophilicity and protection against inhibitors such as EDTA, BME and PMSF. Remarkably, immobilized rHsEst was stable and active in NaCl concentrations as high as 5M. These biochemical characteristics of immobilized rHsEst reveal its potential as a biocatalyst for industrial applications.

Assessment of quadriceps muscle mass by ultrasound in the postoperative period of cardiac surgery.

BACKGROUND: Patients undergoing cardiac surgery are exposed to many factors that activate catabolic and inflammatory pathways, which affect skeletal muscle and are, therefore, related to unfavorable hospital outcomes. Given the limited information on the behavior of muscle mass in critically ill patients, the objective of this study was to evaluate the impact on quantitative and qualitative measurements of quadriceps muscle mass using ultrasound after cardiac surgery. To accomplish this, a prospective, descriptive, and correlational study was conducted at a tertiary care hospital. Quadriceps muscle mass was evaluated via ultrasound in 31 adult patients in the postoperative period of cardiac surgery, with daily follow-up until postoperative day 7, as well as an assessment of associations with negative outcomes at 28 days. RESULTS: A 16% reduction in the cross-sectional area of the rectus femoris was found (95% CI 4.2-3.5 cm2; p 0.002), as well as a 24% reduction in the pennation angle of the rectus femoris (95% CI 11.1-8.4 degrees; p: 0.025). However, changes in the thickness of the rectus femoris, vastus internus, vastus lateralis, the length of the fascicle of the vastus lateralis, the pennation angle of the vastus lateralis, the sarcopenia index, and the Hekmat score were not statistically significant. There was no significant association between quadriceps muscle mass measurements and Intensive Care Unit (ICU) length stay or 28-day mortality. CONCLUSIONS: Patients in the postoperative period of cardiac surgery evaluated by ultrasound exhibit both quantitative and qualitative changes in quadriceps muscle mass. A significant reduction in muscle mass is observed but this is not associated with unfavorable outcomes.

Reducing self-shading effects in Botryococcus braunii cultures: effect of Mg2+ deficiency on optical and biochemical properties, photosynthesis and lipidomic profile.

Microalgae biomass exploitation as a carbon-neutral energy source is currently limited by several factors, productivity being one of the most relevant. Due to the high absorption properties of light-harvesting antenna, photosynthetic cells tend to capture an excessive amount of energy that cannot be entirely channeled through the electron transfer chain that ends up dissipated as heat and fluorescence, reducing the overall light use efficiency. Aiming to minimize this hurdle, in this work we studied the effect of decreasing concentrations of Magnesium (Mg2+) on the chlorophyll a content, photosynthetic performance, biomass and lipid production of autotrophic cultures of Botryococcus braunii LB 572. We also performed, for the first time, a comparative lipidomic analysis to identify the influence of limited Mg2+ supply on the lipid profile of this algae. The results indicated that a level of 0.0037 g L-1 MgSO4 caused a significant decline on chlorophyll a content with a concomitant 2.3-fold reduction in the biomass absorption coefficient. In addition, the Mg2+ limitation caused a decrease in the total carbohydrate content and triggered lipid accumulation, achieving levels of up to 53% DCW, whereas the biomass productivity remained similar for all tested conditions. The lipidome analysis revealed that the lowest Mg2+ concentrations also caused a differential lipid profile distribution, with an enrichment of neutral lipids and an increase of structural lipids. In that sense, we showed that Mg2+ limitation represents an alternative optimization approach that not only enhances accumulation of neutral lipids in B. braunii cells but also may potentially lead to a better areal biomass productivity due to the reduction in the cellular light absorption properties of the cells.

Transformation of Brewery Subproducts into Valuable Biomass Using Mixotrophic Culture of Chlorella pyrenoidosa and Associated Bacteria

Abstract To develop a biorefinery concept applied in the brewery industry, Chlorella pyrenoidosa and a consortium of associated bacteria were cultivated mixotrophically in a continuous photobioreactor using brewery low-value subproducts as an integrative process. Beer production residues were biochemically characterized to assess the most promising options to be used as a nutrient source for microalgal cultivation. Due to its physical and chemical properties, pre-treated weak wort was used to prepare an organic complex culture medium for microalgal biotransformation. Filtration and nitrogen supplementation were necessary to improve nutrient removal and biomass productivity. Maximal removal of nitrate and phosphate obtained were 90% and 100% respectively. Depending on operation conditions, total carbohydrates depuration ranged from 50 - 80%. The initial concentration of total carbohydrates of the weak wort must be adjusted to 2 - 4g/L to maintain a stable equilibrium between microalgal and bacterial growth. The biochemical composition of produced biomass varied depending on the cultivation conditions as well as on its final use. Upon continuous mixotrophic conditions evaluated in this study, C. pyrenoidosa was composed mainly of carbohydrates and protein.

Técnicas de trasplante hepático usadas en el manejo del carcinoma renal de células claras con trombos en la cava inferior que ascienden hasta el diafragma: serie de casos / Liver transplant techniques used in the management of clear renal cell carcinoma with thrombi in the inferior vena cava that ascend to the diaphragm: case series

Introducción. El carcinoma de células renales corresponde al 3 % de todos los tumores sólidos y, de ellos, cerca del 10 % tiene compromiso de la vena cava inferior. La nefrectomía con trombectomía es la mejor alternativa con intención curativa. La mortalidad perioperatoria se encuentra entre el 2 y el 11 %. El objetivo del presente estudio fue presentar una serie de casos de carcinomas renales con trombos de tipo III según la clasificación de Neves-Zincke, en los cuales se usaron con éxito técnicas del trasplante hepático para su extracción.Materiales y métodos. Se presenta una serie de cinco casos, de pacientes sometidos a nefrectomía radical y que presentaban trombo de la vena cava inferior, atendidos en el periodo comprendido entre enero de 2012 y septiembre de 2018.Resultados. De 26 pacientes encontrados con cáncer de células renales, se seleccionaron cinco con trombos de tipo Neves III, cuatro de ellos de tipo IIIa y uno de tipo IIIc. El promedio de edad fue de 63,2 años, cuatro mujeres y un hombre. El promedio de tiempo operatorio fue de 274 minutos y el de pinzamiento de la vena cava inferior fue de 13,6 minutos. El tiempo promedio de estancia en la unidad de cuidados intensivos fue de 2,8 días y el de estancia hospitalaria fue de 9,6 días. Un paciente no presentó ninguna complicación, y los cuatro restantes presentaron complicaciones quirúrgicas menores, I y II de la clasificación de Clavien-Dindo.Conclusión. El uso de maniobras técnicas del trasplante hepático para extraer trombos de la vena cava inferior que no comprometen la aurícula derecha en pacientes con tumores renales, es una alternativa segura con baja morbimortalidad perioperatoria y que puede llegar a garantizar el control de la enfermedad a largo plazo

Introduction. Renal cell carcinoma corresponds to 3% of all solid tumors and about 10% have IVC thrombus. Nephrectomy with thrombectomy is the best choice for a curative treatment. Perioperative mortality may vary between 2 and 11%. The aim of this study is to describe a series of patients with renal tumors and IVC thrombus Neves III in treated succesfully with liver transplant techniques.Materials and methods. We conducted a descriptive case series of five patients who underwent nephrectomy and thrombectomy between January 2012 and September 2018.Results. Of 26 nephectomized patients who had any IVC thrombus, five cases had renal tumors and thrombus Neves III. The mean age was 63.2 years and 80% were women. Eighty percent were Neves IIIa. Mean operative time and IVC clamping were 274 and 13.6 minutes respectively. ICU and hospital stay were 2.8 and 9.6 days. Twenty percent of patients had no complications, the rest had minor complications (Clavien-Dindo I and II).Conclusion. IVC thrombus extraction with liver transplantion technique for renal tumors without right atrium involvement is a safe alternative for patients with low morbility and mortality. It is also a feasible alternative to ensure disease control in a long term

Evaluación financiera de la industria de fabricación de papel, cartón y derivados en Colombia 2010-2015 / Financial evaluation of the paper, cardboard and derivative manufacturing industry in Colombia 2010-2015 / Avaliação financeira da Indústria de fabricação de papel, cartão e produtos em Colombia 2010-2015

RESUMEN Este artículo tiene como propósito evaluar el desempeño financiero de la industria de fabricación de papel, cartón y derivados en Colombia en el período 2010-2015, mediante un análisis de los indicadores contables y de gestión del valor que miden su crecimiento, eficiencia, eficacia y efectividad. Se encuentra que esta industria genera rentabilidades contables en casi todos los años, menos en el 2014; y que el comportamiento de su efectividad depende en orden de importancia a la eficacia en el control de costos y gastos, a la eficiencia del uso de los recursos, quedando como tercer factor el apalancamiento financiero; no obstante, en cada año se destruye valor económico agregado (EVA), y su valor de mercado agregado (VMA) es negativo. Esta industria es destructora de valor porque la rentabilidad del activo neto operacional es inferior al costo de capital, donde la rentabilidad es creciente, con una caída considerable en el 2014, y el costo de capital oscilante. Esto contrasta con el sector homólogo en Estados Unidos de América donde se crea valor en cinco años, con rentabilidades del activo neto operacional superior y costo de capital inferior a la de Colombia. Los resultados encontrados podrían complementarse con estudios similares para grupos de empresas más homogéneos en cuanto a la edad, tamaño y ubicación geográfica. CÓDIGOS JEL G10, M40, L73

ABSTRACT The purpose of this paper is to evaluate the financial performance of the paper paperboard and derivatives industry in Colombia in the period 2010-2015, through an analysis of accounting and value management indicators that measure growth, efficiency, efficacy and effectiveness. It is found that this industry generates accounting returns in almost every year less in 2014; and that the behavior of its effectiveness depends in order of importance to the efficacy in the control of costs and expenses, to the efficiency of the use of resources, leaving as a third factor the financial leverage; however aggregate economic value (EVA) is destroyed each year and its aggregate market value (VMA) is negative. This industry is a value-destroyer because the profitability of net operating assets is lower than the cost of capital, where profitability is increasing, with a considerable drop in 20l4, and the cost of oscillating capital. This contrasts with the counterpart sector in the United States of America where value is created in five years, with higher net operating income and lower capital cost than Colombia. The results found could be complemented with similar studies for groups of companies more homogeneous in age, size and geographical location. JEL CLASSIFICATION G10, M40, L73

RESUMO O objetivo deste artigo é avaliar o desempenho financeiro da indústria de papel, papelão e derivados na Colômbia no período 2010-2015, através de uma análise dos indicadores contábeis e de gestão de valor que medem seu crescimento, eficiência, eficácia e efetividade Verifica-se que esta indústria gera retornos contábeis quase todos os anos, exceto em 2014; e que o comportamento de sua efetividade depende, por ordem de importância, da eficácia no controle de custos e despesas, na eficiência do uso de recursos, com alavancagem financeira como terceiro fator; no entanto, em cada ano, o valor econômico agregado (EVA) é destruído e seu valor agregado de mercado (VMA) é negativo. Essa indústria é uma destruidora de valor porque o retorno sobre os ativos operacionais líquidos é menor do que o custo de capital, onde a lucratividade está aumentando, com uma queda considerável em 2014, e o custo do capital flutua. Isso contrasta com o setor de contrapartida nos Estados Unidos da América, onde o valor é criado em cinco anos, com retornos sobre ativos operacionais líquidos e custos de capital inferiores aos da Colômbia. Os resultados encontrados poderiam ser complementados por estudos semelhantes para grupos de empresas que são mais homogêneas em termos de idade, tamanho e localização geográfica. CLASSIFICAÇÕES JEL G10, M40, L73