Use of cardiovascular events prediction models for the prognosis of a severe coronary artery lesion

Objetivos: Determinar el mejor punto de corte y el grado de conformidad de las escalas de riesgo, Framingham, PROCAM y Reynolds, para el diagnóstico de lesión vascular coronaria arte- rioesclerótica severa a través de la comparación de las áreas bajo la curva de acuerdo con las curvas operativas del receptor (COR). Métodos: Estudio de corte transversal en adultos que fueron sometidos a arteriografía corona- ria. Se aplicaron las escalas Framingham, PROCAM y Reynolds, las dos primeras ajustadas según estudio de calibración colombiano. Luego se realizó la recolección de los datos de manera concurrente en instituciones de referencia en cardiología y hemodinámica en Bogotá. Resultados: De 200 pacientes estudiados, 66% eran mujeres, 37,5% mayores de 70 a ̃nos, 53,2% con hipertensión, 52,7% en sobrepeso u obesidad, 61,5% presentaron valores altos de Proteína C Reactiva ultrasensible (PCRus) y 50% tenían al menos una lesión coronaria mayor de 70%. Se encontraron los mejores puntos de corte, de acuerdo con cada curva de características operativas del receptor (COR): Framingham ajustado 5,8% (sensibilidad 80%, especificidad 41%). PROCAM ajustado 1,7% (sensibilidad 78%, especificidad 45%) y Reynolds 3,8% (sensibilidad 68%, especificidad 45%). Adicionalmente, se encontró que las tres escalas presentaron áreas bajo la curva (ABC) de 0,59, 0,59 y 0,57, respectivamente.Q4Objectives: To determine the best cut-off point and the level of agreement of the Framingham, PROCAM, and Reynolds risk scales, for the diagnosis of a severe atherosclerotic coronary artery lesion by comparing the areas under the receiver operator characteristics (ROC) curves. Methods: A cross-sectional study was carried out on adults that were subjected to coronary angiography. The Framingham, PROCAM, and Reynolds were applied, with the first two adjus- ted to a Colombian calibration study. Data were collected concurrently in the institutions of reference in Cardiology and haemodynamics in Bogota. Results: Of the 200 patients study, 66% were female, and 37.5% greater than 70 years-old. Hypertension was recorded in 53.2%, and overweight and obesity in 52.7%. Elevated levels of high sensitivity C-Reactive Protein (hsCRP) were observed in 61.5% of cases and 50% had at least one major coronary lesion greater than 70%. The best cut-off points according to each of the ROC curves: Adjusted Framingham, 5.8% (sensitivity, 80%, specificity, 41%), Adjusted PROCAM, 1.7% (sensitivity, 78%, specificity, 45%) and Reynolds, 3.8% (sensitivity, 68%, specificity, 45%). Additionally, the three areas under the curve (AUC) were 0.59, 0.59, and 0.57, respectively.Revista Nacional - Indexad

Espacios muestrales estocásticos

Presentamos el informe final que realizamos en la Maestría en Educación Matemática sobre espacios muestrales estocásticos. El análisis didáctico del tema nos permitió formular el diseño, implementación y evaluación de una unidad didáctica. La unidad didáctica se enmarca en la construcción de espacios muestrales y hace referencia a la toma de decisiones del diario vivir. Tuvimos en cuenta dos variables en particular: las personas que se involucran en una situación determinada y los beneficios al tomar algún tipo de decisión. La combinación entre el número de personas y los posibles beneficios que obtiene cada persona genera un espacio muestral estocástico. Nuestra intención consistió en asociar este hecho a un contexto cercano al estudiante

Virtual screening and computational binding free energy calculation of possible glucosamine-like inhibitors for the enzyme hexokinase 2

ilustraciones, diagramas, tablasLa hexoquinasa 2 (HK2) es una enzima con importancia terapéutica humana debido a su relación con des órdenes metabólicos como la diabetes y el desarrollo de células cancerosas (efecto Warburg), por tanto, debemos implementar estrategias para obtener inhibidores efectivos frente a ella. Se ha reportado en la literatura experimental, una serie de glucosaminas 2,6 disustituidas con capacidad de inhibir HK2. En esta tesis desarrollamos una estrategia computacional para identificar compuestos análogos a la glucosamina con potencial afinidad por HK2 utilizando como entrada la información estructural y actividad in vitro del reporte antes mencionado. Para ello realizamos un tamizaje virtual de una base de datos pública mediante relaciones cuantitativas estructura-actividad (QSAR), modelos farmacofóricos y acoplamiento (docking) molecular. Generamos cinco modelos QSAR con una correlación razonable entre las propiedades fisicoquímicas y la actividad biológica experimental (R2P ≥ 0,6. σ2 ≥ 0,6. RMSEP < 2,0 y 0,2 ≤ R2 LOO ≤ 0,6) e identificamos tres moléculas con potencial actividad inhibitoria contra la HK2 (3, 6 y 139 en la numeración de este trabajo). Calculamos la afinidad de estos ligandos mediante simulaciones de dinámica molecular acopladas al método MM-PB(GB)SA. La afinidad de la molécula 3 hacia HK2 es de 6,91 (5,98; 7,85) Kcal mol−1, la de la molécula 6 de -4,11 (-5,04; -3,17) Kcal mol−1 y la de la molécula 139 de 0,49 (-0,44; 1,43) Kcal mol−1. Estas afinidades se encuentran dentro de un rango de energías apropiado a un control negativo y positivo [-16,12 (-17,06; -15,18) Kcal mol−1 y 3,59 (2,66; 4,53) Kcal mol−1], con significancia estadística. La estrategia es confiable para identificar moléculas similares a la glucosamina con potencial capacidad inhibitoria para este sistema, dado que a través de tres estrategias distintas (QSAR, farmacóforo y docking molecular) conseguimos el mismo grupo de moléculas. Además, los resultados se complementan en su aproximación, ya que por un lado el farmacóforo generaliza las características fisicoquímicas idóneas de los ligandos presentadas por los QSAR; y por el otro, el docking molecular tiene en cuenta las interacciones con el receptor, permitiendo mejorar las limitaciones de cada método. Finalmente, describimos un modo de acción para el ligando 6 que se rige mayormente por interacción hidrofóbica, correspondiendo a un mecanismo alternativo presentado por el control positivo, el cual contrasta por presentar en su mayoría interacciones de tipo puente de hidrogeno con el receptor (en su contribución entálpica). (Texto tomado de la fuente)Hexokinase 2 (HK2) is an enzyme with human therapeutic importance due to its relationship with metabolic disorders such as diabetes and cancer cell growing (Warburg effect), therefore, we must implement strategies to obtain effective inhibitors against it. Recently, a series of 2,6-disubstituted glucosamines with the ability to inhibit HK2 have been reported in the experimental literature. In this thesis we developed a computational strategy to identify glucosamine analogues with potential affinity for HK2 using as input the structural information and in vitro activity from the aforementioned report. For this purpose, we performed a virtual screening of a public database using quantitative structure-activity relationships (QSAR), pharmacophoric models and molecular docking. We generated five QSAR models with reasonable correlation between physicochemical properties and experimental biological activity (R2 P ≥ 0,6. σ 2 ≥ 0,6. RMSEP < 2,0 y 0,2 ≤ R2 LOO ≤ 0,6) and identified three molecules with potential inhibitory activity against HK2 (3, 6 and 139 in the numbering of this work). We calculated the affinity of these ligands by molecular dynamics simulations coupled to the MM-PB(GB)SA method. The affinity of molecule 3 toward HK2 is 6,91 (5,98; 7,85) Kcal mol−1 , that of molecule 6 is -4,11 (-5,04; -3,17) Kcal mol−1 and that of molecule 139 is 0,49 (-0,44; 1,43) Kcal mol−1 . These affinities are within a range of energies appropriate to a negative and positive control [-16,12 (-17,06; -15,18) Kcal mol−1 and 3,59 (2,66; 4,53) Kcal mol−1 ], with statistical significance. The strategy is reliable for identifying glucosamine-like molecules with potential inhibitory capacity for this system, since through three different strategies (QSAR, pharmacophore and molecular docking) we obtained the same group of molecules. Moreover, the results complement each other in their approach, since on the one hand the pharmacophore generalizes the ideal physicochemical characteristics of the ligands presented by the QSARs; and on the other hand, molecular docking takes into account the interactions with the receptor, allowing us to improve the limitations of each method. Finally, we describe a mode of action for ligand 6 that is mostly governed by hydrophobic interaction, corresponding to an alternative mechanism presented by the positive control, which contrasts by presenting mostly hydrogen bridge type interactions with the receptor (in its enthalpic contribution).MaestríaMagíster en Ciencias - QuímicaModelamiento computacional de sistemas fisicoquímicosÁrea Curricular en Ciencias Naturale

Qualitative analysis of technical risks in construction projects industrial floor under the methodology PMI®

En el presente artículo se realizó el análisis cualitativo de los riesgos técnicos de la construcción de los pisos industriales de cuatro bodegas del Parque Empresarial San Isidro en el municipio de Tenjo Cundinamarca (Colombia). Para ello, se implementó la metodología del Project Management Institute (PMI). Se realizó una matriz de identificación y evaluación cualitativa de riesgos. La identificación de los riesgos fue llevada a cabo por el ingeniero que tuvo a cargo el proyecto y los riesgos fueron categorizados en las áreas de: estudios, diseños, construcción y puesta en marcha. La evaluación cualitativa se realizó mediante la implementación de unas reglas de calificación adaptadas al proyecto en específico, las calificaciones se hicieron con base a la probabilidad de ocurrencia e impacto del riesgo, posteriormente, se determinó el nivel de importancia para cada riesgo. Luego, los riesgos fueron clasificados en la matriz de probabilidad e impacto. Se realizó una tercera matriz donde se colocó las respuestas planificadas a cada riesgo. Como resultado del análisis se obtuvo una cuarta matriz donde se pudo priorizar los riesgos técnicos con base en la planificación de las respuestas acorde a la calificación. Se determinó que los riesgos negativos con mayor prioridad son los relacionados con el diseño de la cimentación. Finalmente, se espera que el análisis de este caso sirva de modelo para el análisis de riesgos técnicos de la construcción de pisos industriales en el corredor calle 80 de la ciudad de Bogotá.In the present article was realized the qualitative analysis of the technical risks of the industrial floor construction of four industrial warehouse in the San Isidro business park in the town of Tenjo Cundinamarca (Colombia). For this purpose, the methodology of the Project Management Institute (PMI) is implemented. A matrix of identification and evaluation qualitative of risk was performed. The identification of risks was carried out by the engineer who was in charge of the project and the risks were categorized in the following areas: studies, design, construction and commissioning. The qualitative evaluation was performed by implementing qualifying rules adapted in this project, the qualifying were based on the probability of occurrence and impact of risk, then the level of importance for each risk was determined. Next, the risks were classified in the matrix of probability and impact. A third matrix was made, where the planned responses to each risk were performed. As a result of the analysis, a final matrix was obtained, where technical risks were prioritized based on planning responses according to the qualification. It determined that the negative risks with higher priority are related with foundation's design. Finally, the analysis of this case is expected to serve as a model for the analysis of technical risks of the construction of industrial floors in the Bogotá’s 80th Street corridor

Comparative Leaf Water Absorption Between Chaparral Island and Mainland Taxa: a Common Garden Experiment

In California and other Mediterranean-type ecosystems, island species are typically exposed to more fog but less rain than mainland species. Because adaptations to absorb water from fog may conflict with those to minimize water loss, we hypothesized that island species should have greater fog absorption than their mainland congeners due to foliar uptake but at the cost of modifying other leaf structural and functional traits. To determine whether foliar water absorption is an adaptation to insularity, we compared seven physiological and anatomical leaf traits between congeneric island and mainland species of two genera, Ceanothus and Arctostaphylos, in a common garden in Claremont, California. We quantified leaf water potentials, maximum leaf water absorption rates, leaf hydrophobicity, leaf mass per area [LMA], succulence, stomatal density, and wax morphology. All taxa exhibited water permeability through their leaf surfaces, but only one of the three island taxa showed greater water absorption than their mainland counterparts. The island and mainland varieties of C. megacarpus were similar in water absorption and hydrophobicity, but the mainland variety had greater LMA, greater succulence, and thicker epicuticular wax. In Arctostaphylos, insularity promoted species-specific responses: A. catalinae had greater foliar absorption compared to the mainland species, whereas A. insularis displayed mesophytic traits such as hypostomatal morphology, horizontally oriented leaves and low LMA. Relative surface hydrophobicity was not linked to absorption rates, but the mainland species A. glauca had the most hydrophobic leaf surfaces in the study, achieved by their ornate epicuticular wax. Overall, island taxa displayed more mesophytic leaf traits than their mainland congeners. The results may have implications for biogeography in Mediterranean-type ecosystems that may be losing seasonal coastal fog with global change

Digestive hemorrhaging in a patient being treated with anticoagulants

Paciente masculino de 65 años que consulta por cuadro de 12 horas de evolución de dolor abdominal en flanco izquierdo que posteriormente se acompaña de melanemesis, rectorragia, hematuria, pujo y tenesmo rectal y vesical. Como antecedentes de importancia el paciente refiere cardiopatía isquémica con revascularización miocárdica y colocación de stent coronario 6 meses antes, en manejo con antiagregación dual.Q430-33The patient was a sixty-five-year-old male with continuous abdominal pain on the left side which had been developing for 12 hours. Towards the end of that period, the patient showed melanemesis, rectal bleeding, hematuria, whimpering, and rectal and bladder tenesmus. An important event in this patient’s background was ischemic heart disease with myocardial revascularization. A coronary stent had been placed six months before. His condition was being dealt with through dual antiplatelet therapy. He had also presented a deep vein thrombosis with pulmonary embolism three months before

Portable single-lead electrocardiogram device is accurate for QTc evaluation in hospitalized patients

Q1Background: Many commonly used drugs can prolong the QTc interval (QTc), which can lead to potentially life-threatening arrhythmias. In the current era of the COVID-19 pandemic, it is worth mentioning that the disease itself and several drugs used for its treatment have been associated with QTc prolongation. Objective: To evaluate the agreement and clinical precision of a portable single-lead electrocardiogram (ECG) device to measure the QTc interval compared to the standard 12-lead ECG. Methods: In sequential tests, QTc of ECG recordings obtained with the KardiaMobile (KM-1L) device (AliveCor, San Francisco, CA) were compared to QTc obtained with conventional 12-lead ECG. Agreement was evaluated using Bland-Altman plots and Lin's concordance coefficient. Consistency between the 2 devices in determining QTc prolongation (QTc ≥470 ms in males or ≥480 ms in females) was evaluated with kappa statistics. Results: A total of 128 patients with a presumed or confirmed diagnosis of COVID-19 admitted to a university hospital were included. QTc intervals measured with KM-1L were similar to QTc measured with conventional ECG (442.45 ± 40.5 vs 441.65 ± 40.3 ms, P = .15). Bland-Altman analysis showed no significant difference in QTc values (average difference of -0.797, 95% limits of agreement:-13.179; 11.585). Lin's concordance coefficient showed an excellent agreement (0.988, P 0.90). Conclusion: ECG recordings obtained with KM-1L allow an accurate QTc interval assessment. Considering its simplicity of use, this approach has advantages over conventional ECG and can provide an alternative for the evaluation of QTc in hospitalized patients, during the current time of the COVID-19 pandemic and beyond.Revista Internacional - Indexad

The Variable Quiescent X-ray Emission of the Neutron Star Transient XTE J1701-462

We present the results of continued monitoring of the quiescent neutron star low-mass X-ray binary XTE J1701-462 with Chandra and Swift. A new Chandra observation from 2010 October extends our tracking of the neutron star surface temperature from ~800 days to ~1160 days since the end of an exceptionally luminous 19 month outburst. This observation indicates that the neutron star crust may still be slowly cooling toward thermal equilibrium with the core; another observation further into quiescence is needed to verify this. The shape of the overall cooling curve is consistent with that of a broken power law, although an exponential decay to a constant level cannot be excluded with the present data. To investigate possible low-level activity, we conducted a monitoring campaign of XTE J1701-462 with Swift during 2010 April-October. Short-term flares - presumably arising from episodic low-level accretion - were observed up to a luminosity of ~1e35 erg/s, ~20 times higher than the normal quiescent level. We conclude that flares of this magnitude are not likely to have significantly affected the equilibrium temperature of the neutron star and are probably not able to have a measurable impact on the cooling curve. However, it is possible that brighter and longer periods of low-level activity have had an appreciable effect on the equilibrium temperature.Comment: 14 pages, 4 figures - matches published version except for a slight difference in the title due to an ApJ proofreader's mistak

The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance

The all sky surveys done by the Palomar Observatory Schmidt, the European Southern Observatory Schmidt, and the United Kingdom Schmidt, the InfraRed Astronomical Satellite and the 2 Micron All Sky Survey have proven to be extremely useful tools for astronomy with value that lasts for decades. The Wide-field Infrared Survey Explorer is mapping the whole sky following its launch on 14 December 2009. WISE began surveying the sky on 14 Jan 2010 and completed its first full coverage of the sky on July 17. The survey will continue to cover the sky a second time until the cryogen is exhausted (anticipated in November 2010). WISE is achieving 5 sigma point source sensitivities better than 0.08, 0.11, 1 and 6 mJy in unconfused regions on the ecliptic in bands centered at wavelengths of 3.4, 4.6, 12 and 22 microns. Sensitivity improves toward the ecliptic poles due to denser coverage and lower zodiacal background. The angular resolution is 6.1, 6.4, 6.5 and 12.0 arc-seconds at 3.4, 4.6, 12 and 22 microns, and the astrometric precision for high SNR sources is better than 0.15 arc-seconds.Comment: 22 pages with 19 included figures. Updated to better match the accepted version in the A

Dense matter with eXTP

In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry (eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be replicated in a terrestrial laboratory. The tightest statistical constraints on the dense matter equation of state will come from pulse profile modelling of accretion-powered pulsars, burst oscillation sources, and rotation-powered pulsars. Additional constraints will derive from spin measurements, burst spectra, and properties of the accretion flows in the vicinity of the neutron star. Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Science, the eXTP mission is expected to be launched in the mid 2020s.Comment: Accepted for publication on Sci. China Phys. Mech. Astron. (2019