33 research outputs found

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Gestión del conocimiento: perspectiva multidisciplinaria. Volumen 13

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    El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 13 de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada, de acceso abierto a todas las áreas del conocimiento, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico. Con esta colección, se aspira contribuir con el cultivo, la comprensión, la recopilación y la apropiación social del conocimiento en cuanto a patrimonio intangible de la humanidad, con el propósito de hacer aportes con la transformación de las relaciones socioculturales que sustentan la construcción social de los saberes y su reconocimiento como bien público. El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 13, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro cuenta con el apoyo de los grupos de investigación: Universidad Sur del Lago “Jesús María Semprúm” (UNESUR) - Zulia – Venezuela; Universidad Politécnica Territorial de Falcón Alonso Gamero (UPTFAG) - Falcón – Venezuela; Universidad Politécnica Territorial de Mérida Kléber Ramírez (UPTM) - Mérida - Venezuela; Universidad Guanajuato (UG) - Campus Celaya - Salvatierra - Cuerpo Académico de Biodesarrollo y Bioeconomía en las Organizaciones y Políticas Públicas (CABBOPP) - Guanajuato – México; Centro de Altos Estudios de Venezuela (CEALEVE) - Zulia – Venezuela, Centro Integral de Formación Educativa Especializada del Sur (CIFE - SUR) - Zulia – Venezuela; Centro de Investigaciones Internacionales SAS (CEDINTER) - Antioquia – Colombia y diferentes grupos de investigación del ámbito nacional e internacional que hoy se unen para estrechar vínculos investigativos, para que sus aportes científicos formen parte de los libros que se publiquen en formatos digital e impreso

    Impact of oxygen delivery on the development of acute kidney injury in patients undergoing valve heart surgery

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    One of the strongest risk factors for death in individuals undergoing cardiac surgery is Cardiac Surgery Associated-Acute Kidney Injury (CSA-AKI). Although the minimum kidney oxygen delivery index (DO2i) during cardiopulmonary bypass (CPB) has been reported, the optimal threshold value has not yet been established. A prospective study was conducted from June 2012 to January 2016 to asses how DO2i influences the pathogenesis of CSA-AKI, as well as its most favorable cut-off value. DO2 levels were recorded at the beginning, middle, and end of the CPB. The association between DO2i and CSA-AKI was investigated using multivariable logistic regression analysis. The optimal cut-off of DO2i as a predictor of CSA-AKI was determined using Classification and Regression Tree (CART) analysis. A total of 782 consecutive patients were enrolled. Of these, 231 (29.5%) patients developed AKI. Optimal DO2i thresholds of 303 mL/min/m2 during the CPB and 295 mL/min/m2 at the end of the intervention were identified, which increased the odds of CSA-AKI almost two-fold (Odds Ratio (OR), 1.90; 95% CI, 1.12-3.24) during the surgery and maintained that risk (OR 1.94; 95% CI, 1.15-3.29) until the end. Low DO2i during cardiopulmonary bypass is a risk factor for CSA-AKI that cannot be ruled out. Continuous renal oxygen supply monitoring for adult patients could be a promising method for predicting AKI during CPB

    Critically ill patients with community-onset intraabdominal infections: influence of healthcare exposure on resistance rates and mortality

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    The concept of healthcare-associated infections (as opposed to hospital-acquired infections) in intraabdominal infections (IAIs) is scarcely supported by data in the literature. The aim of the present study was to analyse community-onset IAIs (non-postoperative/non-nosocomial) in patients admitted to intensive care units (ICUs), to investigate differences in resistance patterns linked to healthcare exposure and mortality-associated factors. A one-year prospective observational study (17 Spanish ICUs) was performed distributing cases as healthcare-associated infections (HCAI), community-acquired infections (CAI) and immunocompromised patients (ICP). Bacteria producing extended-spectrum β-lactamases (ESBL) and/or carbapenemase (CPE), high-level aminoglycoside- and/or methicillin- and/or vancomycin- resistance were considered antimicrobial resistant (AMR). Mortality-associated factors were identified by regression multivariate analysis. Of 345 patients included (18.8% HCAI, 6.1% ICP, 75.1% CAI), 51.6% presented generalized peritonitis; 32.5% were >75 years (55.4% among HCAI). Overall, 11.0% cases presented AMR (7.0% ESBL- and/or CPE), being significantly higher in HCAI (35.4%) vs. CAI (5.8%) (p75 years (OR = 6.67, 95%CI = 2.56-17.36,p75 years, severity and Candida isolation but not with AMR

    Colombia: investigación sociojurídica

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    illustratorEn la actualidad, la investigación en derecho se adelanta sobre metodologías que declaran estar sustentadas en enfoques reconocidos como el dogmático-jurídico y el sociojurídico, pero también en otros que emergen como el dikelógico, el histórico-jurídico y la fenomenología del derecho. Lo cierto es que en la diversidad metodológica que viene siendo declarada se mantiene la tarea de desarrollar un pensamiento crítico que cada día abre más espacio a la adopción de enfoques por medio de los cuales el derecho amplíe su mirada a las dimensiones de la realidad social que lo definen como ciencia. En la realización de esa labor, este libro puede ser visto como un ejercicio que procura la aplicación del enfoque sociojurídico con perspectiva crítica
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