Clinical characteristics, imaging findings, management, and outcomes of patients with scimitar syndrome at a tertiary referral healthcare center in Colombia.

Scimitar Syndrome is part of a complex spectrum of congenital cardiovascular anomalies related to anomalous pulmonary venous return. Depending on the extent of involvement, treatment can be either expectant or surgical. Prognosis and survival have been controversial, with some results supporting early surgical management. This research aims to disclose the outcomes and describe the management, clinical and imaging characteristics of patients diagnosed with Scimitar Syndrome treated in a tertiary referral healthcare center. Longitudinal descriptive observational study. The study included all patients diagnosed with scimitar syndrome in our institution between January/2011 and December/2022. A description of the sociodemographic and clinical characteristics, diagnostic tools used, treatment features, and patient outcomes is provided. Eleven patients were included, with a mean age at diagnosis of five years (CI 0-17), six of which were female (54.55%). Nine (81.82%) patients had evidence of a scimitar vein on the chest radiograph, six (54.55%) cardiac dextroposition, six (54.55%) pulmonary hypoplasia, five (45.45%) right pulmonary artery hypoplasia, and three (27.27%) had aortopulmonary collaterals. Four (36.36%) patients had horseshoe lungs, and four (36.36%) had bronchopulmonary sequestration. In the associations, two (18.18%) patients were found to have an atrial septal defect, three (27.27%) ventricular septal defect, and one (9%) had Tetralogy of Fallot. Pulmonary hypertension was demonstrated in two (18.18%) patients. Seven (63.64%) required surgical management to correct the scimitar vein, and two patients died due to unrelated complications. Scimitar syndrome presents diagnostic and treatment challenges, necessitating a multidisciplinary approach for timely care. Chest radiography and CT scans are primary diagnostic tools, with surgical intervention often warranted alongside other heart defects or significant hemodynamic repercussions. Medical management is effective for mild to moderate cases. Long-term patient outcomes remain uncertain due to study limitations, but improved life expectancy is anticipated with ongoing care.

Management of right ventricular outflow tract with percutaneous Melody valve implantation in pediatric patients: experience in a high complexity center in Colombia.

BACKGROUND: Congenital heart disease poses a therapeutic challenge, specifically pulmonary valve stenosis. This has been treated for many years with invasive procedures and bioprostheses, which over time, become dysfunctional due to the accumulation of fibrous tissue and calcification. OBJECTIVE: The aim of this study is to describe the use of endovascular management in the right ventricular outflow tract, as the beginning of an ongoing effot to improve pediatric outcomes in developing countries. METHODS: Seven pediatric patients with endovascular management of the right outflow tract are presented. Three of them underwent surgical valvuloplasty with persistent pulmonary stenosis. They decided to insert a percutaneous transcatheter pulmonary valve (PPVI) with a Melody valve using the valve-in-valve technique, with 100% stenosis and no complications associated with the procedure. RESULTS: Four patients with successful percutaneous valve implantation had different congenital heart diseases. In addition, the case of a patient in whom an intentional pulmonary valve fracture was performed, an innovative procedure in pediatric endovascular management in the country, is highlighted. CONCLUSIONS: The procedure was minimally invasive, safe, and effective. The IVPP technique could be a viable option in our country for managing failed primary valve implantations or even in native tracts.

ANTECEDENTES: Las cardiopatías congénitas plantean un desafío terapéutico, específicamente la estenosis de la válvula pulmonar. Esta ha sido tratada durante muchos años con procedimientos invasivos e inserción de bioprótesis, que con el tiempo se vuelven disfuncionales y pueden reestenosarse por acumulación de tejido fibroso y calcificación. Debido a las complicaciones generadas por la injuria quirúrgica, se han descrito medidas menos invasivas para el manejo de la estenosis residual e inicial por medios endovasculares en adultos y más recientemente en población pediátrica. OBJETIVO: El objetivo de este reporte es describir la misma en el manejo endovascular del tracto de salida del ventrículo derecho, como el inicio de un trabajo continuo para la mejoría de los resultados pediátricos en países en vía de desarrollo. MÉTODOS: Se presentan siete casos pediátricos de manejo endovascular del tracto de salida derecho; tres de ellos sometidos a valvuloplastia quirúrgica con persistencia de la estenosis pulmonar, por lo cual se decidió inserción percutánea de una válvula pulmonar (IVPP) transcatéter con válvula Melody utilizando la técnica valve-in-valve, con lo que se consiguió una resolución del 100% de la estenosis y no se presentó ningún tipo de complicación asociada al procedimiento. RESULTADOS: En cuatro pacientes se logró una implantación exitosa de la válvula por vía percutánea en diferentes cardiopatías congénitas, siendo uno de ellos en tracto nativo; además, destaca el caso de un paciente en quien se realizó fractura intencional de la válvula pulmonar, procedimiento innovador en el manejo endovascular pediátrico en Colombia. CONCLUSIONES: En estos pacientes el procedimiento resultó ser poco invasivo, seguro y efectivo. La técnica IVPP podría ser considerada una opción viable en Colombia (y en otros países en desarrollo) para el manejo de implantes valvulares primarios fallidos o incluso en tractos nativos.

Manejo del tracto de salida del ventrículo derecho con implante percutáneo de válvula Melody en pacientes pediátricos: experiencia en un centro de alta complejidad en Colombia / Management of right ventricular outflow tract with percutaneous Melody valve implantation in pediatric patients: experience in a high complexity center in Colombia

Resumen Antecedentes: Las cardiopatías congénitas plantean un desafío terapéutico, específicamente la estenosis de la válvula pulmonar. Esta ha sido tratada durante muchos años con procedimientos invasivos e inserción de bioprótesis, que con el tiempo se vuelven disfuncionales y pueden reestenosarse por acumulación de tejido fibroso y calcificación. Debido a las complicaciones generadas por la injuria quirúrgica, se han descrito medidas menos invasivas para el manejo de la estenosis residual e inicial por medios endovasculares en adultos y más recientemente en población pediátrica. Objetivo: El objetivo de este reporte es describir la misma en el manejo endovascular del tracto de salida del ventrículo derecho, como el inicio de un trabajo continuo para la mejoría de los resultados pediátricos en países en vía de desarrollo. Métodos: Se presentan siete casos pediátricos de manejo endovascular del tracto de salida derecho; tres de ellos sometidos a valvuloplastia quirúrgica con persistencia de la estenosis pulmonar, por lo cual se decidió inserción percutánea de una válvula pulmonar (IVPP) transcatéter con válvula Melody utilizando la técnica valve-in-valve, con lo que se consiguió una resolución del 100% de la estenosis y no se presentó ningún tipo de complicación asociada al procedimiento. Resultados: En cuatro pacientes se logró una implantación exitosa de la válvula por vía percutánea en diferentes cardiopatías congénitas, siendo uno de ellos en tracto nativo; además, destaca el caso de un paciente en quien se realizó fractura intencional de la válvula pulmonar, procedimiento innovador en el manejo endovascular pediátrico en Colombia. Conclusiones: En estos pacientes el procedimiento resultó ser poco invasivo, seguro y efectivo. La técnica IVPP podría ser considerada una opción viable en Colombia (y en otros países en desarrollo) para el manejo de implantes valvulares primarios fallidos o incluso en tractos nativos.

Abstract Background: Congenital heart disease poses a therapeutic challenge, specifically pulmonary valve stenosis. This has been treated for many years with invasive procedures and bioprostheses, which over time, become dysfunctional due to the accumulation of fibrous tissue and calcification. Objective: The aim of this study is to describe the use of endovascular management in the right ventricular outflow tract, as the beginning of an ongoing effot to improve pediatric outcomes in developing countries. Methods: Seven pediatric patients with endovascular management of the right outflow tract are presented. Three of them underwent surgical valvuloplasty with persistent pulmonary stenosis. They decided to insert a percutaneous transcatheter pulmonary valve (PPVI) with a Melody valve using the valve-in-valve technique, with 100% stenosis and no complications associated with the procedure. Results: Four patients with successful percutaneous valve implantation had different congenital heart diseases. In addition, the case of a patient in whom an intentional pulmonary valve fracture was performed, an innovative procedure in pediatric endovascular management in the country, is highlighted. Conclusions: The procedure was minimally invasive, safe, and effective. The IVPP technique could be a viable option in our country for managing failed primary valve implantations or even in native tracts.

Experience of percutaneous closure of small to large patent ductus arteriosus with Nit-Occlud® device in a tertiary referral hospital in Colombia.

Background: The decision to close patent ductus arteriosus should always be individualized and taken together with the child's family once the risks and benefits of both choices have been exposed. Objective: This study aims to report the experience and outcomes in patients undergoing endovascular closure of small to medium-size PDA with a Nit-Occlud® device in a tertiary referral hospital in Colombia. Methods: Longitudinal descriptive study, which included all patients under 18 years of age who underwent percutaneous ductal closure with Nit-Occlud® device between January 1, 2011, and February 1, 2023. Patients with associated complex congenital heart disease requiring surgical management, pregnant patients, and patients with incomplete data regarding studied variables were excluded from the study. Results: Eighty-seven patients were documented, with a mean age, weight, and height at closure of 51 months, 14 kg, and 95.83 cm, respectively. About 70% of the patients (n = 61) were female, 76% were under 6-years-old and only one patient was over 15. The average size of the ductus at the pulmonary end was 2 mm. Four of the total number of patients did not achieve PDA closure during the procedure. Of the remaining 83, complete immediate closure was achieved in 81 patients. A device exchange for a larger device was required during the same procedure in one of the cases. Two patients presented residual shunt of 0.5 mm during follow-up, and one required a new procedure for device closure 10 months later. Only one device presented repeatedly embolization to the aorta, requiring surgical removal. As a technical difficulty, one device presented repeated passage into the aorta, so it was decided to remove it before releasing it to avoid complications, and given the complex anatomy of the ductus, surgical closure was indicated. Among the complications, one patient presented a hematoma of the subcutaneous tissue in the right thigh, which improved with medical management, and no deaths related to the procedure were registered. Conclusions: Using the Nit-Occlud® device to close small to moderate-sized ductus remains a safe and effective strategy with successful closure rates at 1-year follow-up irrespective of age, weight, height, or whether it involves a small or medium-sized duct. Despite our limitations, results concerning adverse effects are comparable to those observed in multicentric studies conducted in other regions.

Antecdentes: La decisión de cerrar el conducto arterioso permeable (CAP) siempre debe ser individualizada y tomada en conjunto con la familia del niño una vez expuestos los riesgos y beneficios de ambas opciones. Objetivo: Este estudio tiene como objetivo informar la experiencia y los resultados en pacientes sometidos a cierre endovascular del CAP de tamaño pequeño a mediano con un dispositivo Nit-Occlud® en un hospital de tercer nivel de referencia en Colombia. Método: Estudio descriptivo longitudinal, que incluyó a todos los pacientes menores de 18 años a quienes se les realizó cierre ductal percutáneo con dispositivo Nit-Occlud® entre el 1 de enero de 2011 y el 1 de febrero de 2023. Se excluyeron: pacientes con cardiopatía congénita compleja asociada que requirieron manejo quirúrgico, pacientes embarazadas y pacientes con datos incompletos sobre las variables estudiadas. Resultados: Se documentaron 87 pacientes, con edad, peso y talla promedio al cierre de 51 meses, 14 kg y 95.83 cm, respectivamente. El 70% de los pacientes (n = 61) eran mujeres, el 76% tenían menos de seis años y solo un paciente tenía más de 15 años. El tamaño medio del conducto en el extremo pulmonar fue de 2 mm. Cuatro del total de pacientes no lograron el cierre del CAP durante el procedimiento. De los 83 restantes, se logró el cierre inmediato completo en 81 pacientes. En uno de los casos fue necesario cambiar el dispositivo por uno más grande durante el mismo procedimiento. Dos pacientes presentaron shunt residual de 0.5 mm durante el seguimiento y uno requirió un nuevo procedimiento para cierre del dispositivo diez meses después. Solo un dispositivo presentó embolización repetida en la aorta, requiriendo extracción quirúrgica. Como dificultad técnica, un dispositivo presentó paso repetido hacia la aorta, por lo que se decidió retirarlo antes de liberarlo para evitar complicaciones y dada la compleja anatomía del ductus se indicó cierre quirúrgico. Entre las complicaciones, un paciente presentó un hematoma del tejido subcutáneo en el muslo derecho, que mejoró con el manejo médico, y no se registraron muertes relacionadas con el procedimiento. Conclusiones: El uso del dispositivo Nit-Occlud® para cerrar conductos de tamaño pequeño a moderado sigue siendo una estrategia segura y eficaz con tasas de cierre exitoso al año de seguimiento, independientemente de la edad, el peso, la altura o si se trata de un conducto de tamaño pequeño o mediano. A pesar de nuestras limitaciones, los resultados sobre los efectos adversos son comparables a los observados en estudios multicéntricos realizados en otras regiones.

20 years of experience with the Fontan procedure: characteristics and clinical outcomes of children in a tertiary referral hospital.

INTRODUCTION: Without participating in a contractile chamber, the Fontan procedure seeks to create a separation of oxygenated and deoxygenated blood in patients with univentricular heart, reducing the risks of long-term hypoxemia and improving their survival. This study describes the clinical outcomes of children undergoing the Fontan procedure between 2000 and 2020 in a tertiary referral hospital care centre in southwestern Colombia. MATERIALS AND METHODS: A retrospective observational descriptive study. The 81 patients who underwent the Fontan procedure were included. Categorical variables were presented with percentages and continuous variables with measures of central tendency according to the distribution of the data evaluated through the Shapiro-Wilk test. Sociodemographic, clinical, surgical variables, complications, and mortality were described. RESULTS: Between 2000 and 2020, 81 patients underwent the Fontan procedure: 43 (53.1%) males and a median age of 5.3 years (interquartile range 4.3-6.6). The most common diagnosis was tricuspid atresia (49.4%). The median mean pulmonary arterial pressure was 12 mmHg (interquartile range 10-15), the Nakata index 272 mm2/m2 (interquartile range 204-327), and the McGoon index (interquartile range 1.86-2.3). Seventy-two (88.9%) patients underwent extracardiac Fontan and 44 (54.3%) patients underwent fenestration. The median hospitalisation days were 19 days. The main complication was coagulopathy (19.8%), mortality in the first month between 2000 and 2010 was 8.6%, and after 2010 was 1.2%. CONCLUSION: The Fontan procedure is a palliative surgery for children with complex heart disease. According to anatomical and physiological variables, the proper choice of patients determines the short- and long-term results.

Características y desenlaces clínicos de pacientes menores de 18 años tratados con oxigenación con membrana extracorpórea posterior a cirugía para la reparación o paliación de cardiopatías congénitas / Characteristics and clinical outcomes of patients under 18 years of age treated with extracorporeal membrane oxygenation after surgery for the repair or palliation of congenital heart disease

Resumen: Objetivo: determinar las características y desenlaces clínicos de pacientes menores de 18 años tratados con oxigenación con membrana extracorpórea (ECMO) posterior a cirugía para la reparación o paliación de cardiopatías congénitas en un centro de referencia del suroccidente colombiano entre 2015 y 2020. Método: estudio descriptivo longitudinal con recolección retrospectiva de la información. Resultados: entre enero de 2015 y diciembre de 2020, 77 pacientes requirieron ECMO posterior a cirugía cardiaca pediátrica, con una mediana de edad de < 1 mes, mediana de peso de 4 kg, tiempo de circulación extracorpórea de 202 minutos y tiempo de pinzamiento aórtico de 95 minutos. La cardiopatía congénita más ingresada a ECMO fue el síndrome de corazón izquierdo hipoplásico (19.4%) en su posquirúrgico de Norwood (18.1%). La mediana del tiempo de ECMO fue de 111 horas. La indicación más frecuente fue la disfunción ventricular (80.5%). El 80.5% presentó complicaciones y la reintervención por sangrado fue la más frecuente (46.7%). La sobrevida a la ECMO fue del 48% y la sobrevida general al momento del alta fue de 25.97%. La edad < 1 mes (p = 0.030), el ácido láctico preECMO ≥ 5 mmol/l (p = 0.014) y el tiempo de normalización del lactato ≥ 24 horas (0.021), se asociaron a un mayor riesgo de mortalidad al egreso hospitalario. Conclusiones: la ECMO proporciona un soporte adecuado posterior a la cirugía cardiaca pediátrica. La edad < 1 mes, el ácido láctico preECMO ≥ 5 mmol/L y el tiempo de normalización del lactato ≥ 24 horas fueron las variables que se asociaron con un mal resultado y mortalidad hospitalaria.

Abstract: Objective: to determine the characteristics and clinical outcomes of patients under 18 years of age treated with extracorporeal membrane oxygenation (ECMO) after surgery for the repair or palliation of congenital heart disease. Method: longitudinal descriptive study with retrospective data collection. Results: between January 2015 and December 2020, 77 patients required ECMO after pediatric cardiac surgery with a median age of < 1 month, median weight of 4 kg, ECC time 202 minutes (IQR 125-272 minutes), aortic cross-clamp time 95 minutes. 76.6% were supported with ECMO prior to their return to the ICU. The congenital heart disease most frequently admitted to ECMO was hypoplastic left heart syndrome (19.4%) in the Norwood postoperative period (18.1%). The median time of ECMO was 111 hours. The most frequent indication was ventricular dysfunction (80.5%). 80.5% presented complications and reoperation for bleeding was the most frequent of these (46.7%). ECMO survival was 48% and overall survival at discharge was 25.97%. Age < 1 month (p = 0.030), pre-ECMO lactic acid ≥ 5 mmol/l (p = 0.014), OR 0.260 and time of normalization of lactate ≥ 24 hours (0.021), OR 0.24 were associated with a higher risk of mortality at hospital discharge. Conclusions: ECMO provides adequate support after surgery for the repair or palliation of congenital heart disease. Age < 1-month, pre-ECMO lactic acid ≥ 5 mmol/l, and lactate normalization time ≥ 24 hours were the variables that were associated with poor outcome and hospital mortality.

A Game Theory-Based Approach for Modeling Autonomous Vehicle Behavior in Congested, Urban Lane-Changing Scenarios.

Autonomous vehicles are expected to display human-like behavior, at least to the extent that their decisions can be intuitively understood by other road users. If this is not the case, the coexistence of manual and autonomous vehicles in a mixed environment might affect road user interactions negatively and might jeopardize road safety. To this end, it is highly important to design algorithms that are capable of analyzing human decision-making processes and of reproducing them. In this context, lane-change maneuvers have been studied extensively. However, not all potential scenarios have been considered, since most works have focused on highway rather than urban scenarios. We contribute to the field of research by investigating a particular urban traffic scenario in which an autonomous vehicle needs to determine the level of cooperation of the vehicles in the adjacent lane in order to proceed with a lane change. To this end, we present a game theory-based decision-making model for lane changing in congested urban intersections. The model takes as input driving-related parameters related to vehicles in the intersection before they come to a complete stop. We validated the model by relying on the Co-AutoSim simulator. We compared the prediction model outcomes with actual participant decisions, i.e., whether they allowed the autonomous vehicle to drive in front of them. The results are promising, with the prediction accuracy being 100% in all of the cases in which the participants allowed the lane change and 83.3% in the other cases. The false predictions were due to delays in resuming driving after the traffic light turned green.

A seismically induced onshore surge deposit at the KPg boundary, North Dakota.

The most immediate effects of the terminal-Cretaceous Chicxulub impact, essential to understanding the global-scale environmental and biotic collapses that mark the Cretaceous-Paleogene extinction, are poorly resolved despite extensive previous work. Here, we help to resolve this by describing a rapidly emplaced, high-energy onshore surge deposit from the terrestrial Hell Creek Formation in Montana. Associated ejecta and a cap of iridium-rich impactite reveal that its emplacement coincided with the Chicxulub event. Acipenseriform fish, densely packed in the deposit, contain ejecta spherules in their gills and were buried by an inland-directed surge that inundated a deeply incised river channel before accretion of the fine-grained impactite. Although this deposit displays all of the physical characteristics of a tsunami runup, the timing (<1 hour postimpact) is instead consistent with the arrival of strong seismic waves from the magnitude Mw ∼10 to 11 earthquake generated by the Chicxulub impact, identifying a seismically coupled seiche inundation as the likely cause. Our findings present high-resolution chronology of the immediate aftereffects of the Chicxulub impact event in the Western Interior, and report an impact-triggered onshore mix of marine and terrestrial sedimentation-potentially a significant advancement for eventually resolving both the complex dynamics of debris ejection and the full nature and extent of biotic disruptions that took place in the first moments postimpact.

Metagenomic analysis of a high carbon dioxide subsurface microbial community populated by chemolithoautotrophs and bacteria and archaea from candidate phyla.

Research on geologic carbon sequestration raises questions about potential impacts of subsurface microbiota on carbon cycling and biogeochemistry. Subsurface, high-CO2 systems are poorly biologically characterized, partly because of difficulty accessing high-volume, uncontaminated samples. CO2 -driven Crystal Geyser (CG, Utah, USA), an established geologic carbon sequestration analogue, provides high volumes of deep (∼ 200-500 m) subsurface fluids. We explored microbial diversity and metabolic potential in this high-CO2 environment by assembly and analysis of metagenomes recovered from geyser water filtrate. The system is dominated by neutrophilic, iron-oxidizing bacteria, including 'marine' Mariprofundus (Zetaproteobacteria) and 'freshwater' Gallionellales, sulfur-oxidizing Thiomicrospira crunogena and Thiobacillus-like Hydrogenophilales. Near-complete genomes were reconstructed for these bacteria. CG is notably populated by a wide diversity of bacteria and archaea from phyla lacking isolated representatives (candidate phyla) and from as-yet undefined lineages. Many bacteria affiliate with OD1, OP3, OP9, PER, ACD58, WWE3, BD1-5, OP11, TM7 and ZB2. The recovery of nearly 100 genes encoding ribulose-1,5 bisphosphate carboxylase-oxygenase subunit proteins of the Calvin cycle and AMP salvage pathways suggests a strong biological role in high-CO2 subsurface carbon cycling. Overall, we predict microbial impacts on subsurface biogeochemistry via iron, sulfur, and complex carbon oxidation, carbon and nitrogen fixation, fermentation, hydrogen metabolism, and aerobic and anaerobic respiration.

Standardizing radiation dose reporting in the pediatric cardiac catheterization laboratory-a multicenter study by the CCISC (Congenital Cardiovascular Interventional Study Consortium).

OBJECTIVES: We examine normalized air Kerma area product (PKA ) by body weight (PKA /BW) as a reference value of radiation dose and benchmark PKA /BW in pediatric laboratories using a multicenter registry database. BACKGROUND: Reduction of radiation dose is an important quality improvement task in pediatric cardiac catheterization laboratories. Physicians need to agree on a standard method of reporting radiation dose that would allow comparisons to be made between operators and institutions. METHODS: This was a multicenter observational study of radiation dose in pediatric laboratories. Patient demographic, procedural and radiation data including fluoroscopic time and PKA (µGy m(2) ) were analyzed. PKA /BW was obtained by indexing PKA to body weight. RESULTS: A total of 8,267 pediatric catheterization procedures (age <18 years) were included from 16 institutions. The procedures consisted of diagnostic (n = 2,827), transplant right ventricular (RV) biopsy (n = 1,172), and interventional catheterizations (n = 4268). PKA correlated with body weight better than with age and best correlated with weight-fluoroscopic time product. PKA /BW showed consistent values across pediatric ages. Interventional catheterizations had the highest PKA /BW (50th, 75th, and 90th percentiles: 72, 151, and 281 µGy m(2) /kg), followed by diagnostic (59, 105, and 175 µGy m(2) /kg) and transplant RV biopsy (27, 79, and 114 µGy m(2) /kg). CONCLUSION: PKA /BW appeared to be the most reliable standard to report radiation dose across all procedure types and patient age. We recommend PKA /BW to be used as the standard unit in documenting radiation usage in pediatric laboratories and can be used to evaluate strategies to lower radiation dosage in pediatric patients undergoing cardiac catheterizations. © 2014 Wiley Periodicals, Inc.

Standardizing Radiation Dose Reporting in thePediatric Cardiac Catheterization Laboratory—AMulticenter Study by the CCISC (CongenitalCardiovascular Interventional Study Consortium)

We examine normalized air Kerma area product (PKA) by body weight(PKA/BW) as a reference value of radiation dose and benchmark PKA/BW in pediatriclaboratories using a multicenter registry database. Background: Reduction of radiationdose is an important quality improvement task in pediatric cardiac catheterizationlaboratories. Physicians need to agree on a standard method of reportingradiation dose that would allow comparisons to be made between operators andinstitutions. Methods: This was a multicenter observational study of radiation dosein pediatric laboratories. Patient demographic, procedural and radiation data includingfluoroscopic time and PKA (mGy m2) were analyzed. PKA/BW was obtained byindexing PKA to body weight. Results: A total of 8,267 pediatric catheterization procedures(age <18 years) were included from 16 institutions. The procedures consistedof diagnostic (n52,827), transplant right ventricular (RV) biopsy (n51,172),and interventional catheterizations (n54268). PKA correlated with body weight betterthan with age and best correlated with weight–fluoroscopic time product. PKA/BWshowed consistent values across pediatric ages. Interventional catheterizations hadthe highest PKA/BW (50th, 75th, and 90th percentiles: 72, 151, and 281 lGy m2/kg),followed by diagnostic (59, 105, and 175 lGy m2/kg) and transplant RV biopsy (27,79, and 114 lGy m2/kg). Conclusion: PKA/BW appeared to be the most reliablestandard to report radiation dose across all procedure types and patient age. We recommend PKA/BW to be used as the standard unit in documenting radiationusage in pediatric laboratories and can be used to evaluate strategies to lower radiationdosage in pediatric patients undergoing cardiac catheterizations.

Método para la actividad cognoscitiva en los estudiantes de medicina ecuatorianos utilizando la web 4.0 / Method for cognitive activity in ecuadorian medical students using web 4.0

El uso de las tecnologías de la información y las comunicaciones tiene un impacto en el proceso docente educativo, sin embargo su uso aún carece de sistematicidad coherente en función de las mejoras de este encargo social. El objetivo de este trabajo es contribuir a generalizar el método para la actividad cognoscitiva, utilizando los entornos virtuales de aprendizaje mediante la web 4.0, para la mejora del proceso enseñanza-aprendizaje en las carreras médicas del Ecuador. Se utiliza como unidad investigativa la Universidad de Guayaquil, en la asignatura Pediatría del quinto año de la carrera de medicina. Los métodos fundamentales utilizados fueron el analítico sintético y el tránsito de lo abstracto a lo concreto en el orden teórico, el análisis de documentos, la observación y la encuesta en el práctico. Los resultados se evidencian en que el método para la actividad cognoscitiva desarrolla un proceso de acciones a partir de la motivación, utilizando la base orientadora para la acción tipo tres, permite la ejecución de acciones y operaciones mediante la construcción de metaanálisis en Ciencias de la Salud, llevando a procesos de abstracción y a generar constructos transdisciplinarios, capaces de dar solución a problemas prototípicos emergentes en Pediatría. Se llega a concluir en esta investigación que se generalizó el método para la actividad cognoscitiva, utilizando los entornos virtuales de aprendizaje mediante la web 4.0, lo cual evidencia mejoras en el proceso docente educativo en las carreras médicas del Ecuador(AU)

The use of information and communication technologies has an impact on the educational process. However, they are not systematically applied for improving this social task. This paper aims to spread the method for cognitive activity, using virtual learning environments through the web 4.0, in order to improve the teaching-learning process in medical studies in Ecuador. The Pediatrics course taught in the fifth year of the medical program in the University of Guayaquil is used as unit of analysis. The basic methods applied were the analytic-synthetic and the transition from the abstract to the concrete for theoretical analysis, and document analysis, observation and survey for practical research. Results show that the method for cognitive activity develops an action process based on motivation, using the third type of orientation basis of actions, allows the implementation of actions and operations by building meta-analysis in Health Sciences, which leads to abstraction processes and generation of transdisciplinary constructs capable of solving emerging prototypical problems in Pediatrics. It is concluded that the method for cognitive activity was spread using virtual learning environments through web 4.0, which shows improvements in the educational process of medical studies in Ecuador(AU)

Entornos virtuales de aprendizaje y educación a distancia: fundamentación psicopedagógica en la educación superior / Virtual Learning Environments and Distance education: psycho-pedagogical bases in higher education

Los avances de las tecnologías de la información y las comunicaciones traen aparejado un desarrollo en el proceso de enseñanza aprendizaje, con mayor énfasis en las universidades. El objetivo de este trabajo es establecer los fundamentos psicopedagógicos del uso de entornos virtuales de aprendizaje para la educación a distancia en la educación superior. Se plantean y analizan los postulados psicopedagógicos que deben contener los cursos diseñados para la educación a distancia sobre plataformas gestoras en la enseñanza superior. Como conclusión se puede apuntar que fueron establecidos los aspectos psicopedagógicos que sustentan el empleo de los entornos virtuales de aprendizaje para la educación a distancia en el contexto de las universidades(AU)

Advances in information and communication technologies bring about a development in the teaching-learning process, particularly in universities. This paper aims at establishing the psycho-pedagogical bases of using virtual learning environments for distance education in higher education. The psycho-pedagogical postulates that must be considered in courses on management platforms designed for distance education in higher education are formulated and analyzed. In conclusion, it may be said that the psycho-pedagogical aspects that support the use of virtual learning environments for distance education in the context of universities were established(AU)

Las tecnologías de la información y las comunicaciones, las del aprendizaje y del conocimiento y las tecnologías para el empoderamiento y la participación como instrumentos de apoyo al docente de la universidad del siglo XXI / The Information and communication technologies, learning and knowledge technologies and technologies for empowerment and participation as tools to support the university Teachers of the XXI century

Es el entorno educativo uno de los que mayores transformaciones ha sufrido con este acelerado desarrollo de las tecnologías de la información y las comunicaciones; es allí donde aparece el concepto de tecnologías del aprendizaje y del conocimiento y tecnologías para el empoderamiento y la participación. El propósito del presente trabajo es contribuir a la reflexión que debe realizar continuamente la educación, y particularmente los docentes, de la Universidad del siglo XXI frente al uso de las tecnologías de la información y la comunicación. Como principal resultado se exponen algunos comentarios sobre acercamiento a la competencia digital de los estudiantes del siglo XXI. Aun cuando se ha demostrado que estas tecnologías constituyen un fenómeno social de gran trascendencia que ha transformado la vida de millones, también se ha reconocido que su impacto en la educación dista de sus potencialidades(AU)

The learning environment has suffered major transformations with the rapid development of the information and communications technologies; in this context the concept of learning and knowledge technologies and technologies for the empowerment and participation emerges. This paper aims at contributing to the reflection on the use of information and communication technologies that must be continually made in education, especially among teachers of the 21st century University. As main result, some comments on the digital competence of students of the 21st century are included. Although it has been demonstrated that these technologies are a social phenomenon of great significance that has changed the lives of millions of people, it has also been recognized that their impact on education is far from their potential(AU)

Enfoque práctico del síndrome metabólico en pediatría: [revisión] / Practical approach to metabolic syndrome in pediatrics: [review]

El síndrome metabólico en pediatría identifica a un grupo de niños con alto riesgo de presentar eventos cardiocerebrovascular y de diabetes tipo 2 a partir de los seis años de edad. La detección temprana y tratamiento óptimo constituyen el pilar fundamental para disminuir la morbimortalidad cardiovascular a mediano y largo plazo. Esta terapéutica creará hábitos saludables familiares y promoverá el control de los factores de riesgo como alteraciones metabólicas, hipertensión arterial y obesidad en cada integrante independiente de su edad. El presente artículo muestra un abordaje práctico en el ámbito clínico de los pacientes pediátricos a partir de los seis años...

The metabolic syndrome in pediatrics identify a high risk population for cardiocerebrovascular events and type 2 diabetes since six years old. Early detection and treatment of risk factors constitute the main point of intervention to decrease the morbidity and mortality related with cardiovascular disease in the medium and long terms. This treatment will create healthy family habits and it will promote the control of these risk factors in each family member. This article presents a practical approach on this issue in pediatric clinical care since six years of age...

Surface characterization of cotton coated by a thin film of polystyrene with and without a cross-linking agent.

Thin polystyrene film coated on cotton was successfully formed by admicellar polymerization. Divinylbenzene (DVB) was used as a cross-linking agent to form networked polystyrene to improve film coverage. A wettability test and XPS analysis were used to characterize the coated surface. The optimum amount of DVB was around 1%. At this amount, the film coverage was most complete, as judged by the reduction of the O1s signal in XPS analysis.

X-ray photoelectron spectroscopic studies of hydrophilic surfaces modified via admicellar polymerization.

Admicellar polymerization with styrene monomer was used to coat the surface of two porous solids: titanium dioxide and alumina. X-ray photoelectron spectroscopy (XPS) measurements clearly indicate that after admicellar polymerization, organic material and surfactant are present on the surface of the solids. Water washes, performed immediately after admicellar polymerization, were successful in removing approximately 30% of the organic material, presumably mostly surfactant. The water wash was followed by Soxhlet extraction with toluene, with no measurable removal of organic material according to ignition loss measurements of the solid, gel permeation chromatography of the extracting solvent and also UV/VIS spectroscopy of the extracting solvent. However, there was a 5-15% drop in organic material after Soxhlet extraction according to XPS measurements. This difference is attributed to the difference in sampling; XPS samples only the exterior surface area while these bulk measurements sample both the interior and exterior surface area. This study details the ability of different washing steps to remove materials from the porous substrates used in this study.

Comparing the evidence relevant to impact and flood basalt at times of major mass extinctions.

The five major mass extinctions identified in 1982 by Raup and Sepkoski have expanded to six, with the suggestion that the Permian-Triassic extinction was a double event. Is there a general explanation for great mass extinctions, or can they result from different triggers, or even from internal system instabilities? The two most-discussed candidates for a general extinction mechanism are impacts and flood-basalt eruptions. A compilation of evidence for impact at the times of mass extinctions shows that this cause is abundantly confirmed in the case of the Cretaceous-Tertiary extinction and the late Eocene, which is a time of minor and gradual extinction, but little or no evidence connects other major extinctions to impact. On the other hand, there is a remarkable time correlation between flood basalts and four major extinctions, but no other evidence that flood basalts cause mass extinctions. The evidence for an impact-extinction linkage is strikingly different from that for a connection between flood basalts and extinctions. Flood basalts cover larger areas than craters and their associated thick ejecta blankets, which are thus less likely to be found. Impacts distribute proxies globally at instantaneous time horizons, whereas flood-basalt events are extended in time, and no remote proxies have been recognized. Many global killing mechanisms have been proposed in the case of impacts, but few have been suggested for flood basalts. It is possible that flood basalts are triggered by impact, but it is not obvious how impacts could result from anything other than chance. The hypothesis that impacts are the general cause of mass extinctions has not received supporting evidence, but has not been falsified. The hypothesis that flood basalts are the general cause of mass extinctions is supported by evidence from timing, but is not susceptible to falsification. Other candidates for general extinction causes, especially sea-level changes and system instabilities, would require separate treatment. The question is still very much open.