Sustainable Synthesis of Metal-Doped Lignin-Derived Electrospun Carbon Fibers for the Development of ORR Electrocatalysts.

The aim of this work is to establish the Oxygen Reduction Reaction (ORR) activity of self-standing electrospun carbon fiber catalysts obtained from different metallic salt/lignin solutions. Through a single-step electrospinning technique, freestanding carbon fiber (CF) electrodes embedded with various metal nanoparticles (Co, Fe, Pt, and Pd), with 8-16 wt% loadings, were prepared using organosolv lignin as the initial material. These fibers were formed from a solution of lignin and ethanol, into which the metallic salt precursors were introduced, without additives or the use of toxic reagents. The resulting non-woven cloths were thermostabilized in air and then carbonized at 900 °C. The presence of metals led to varying degrees of porosity development during carbonization, improving the accessibility of the electrolyte to active sites. The obtained Pt and Pd metal-loaded carbon fibers showed high nanoparticle dispersion. The performance of the electrocatalyst for the oxygen reduction reaction was assessed in alkaline and acidic electrolytes and compared to establish which metals were the most suitable for producing carbon fibers with the highest electrocatalytic activity. In accordance with their superior dispersion and balanced pore size distribution, the carbon fibers loaded with 8 wt% palladium showed the best ORR activity, with onset potentials of 0.97 and 0.95 V in alkaline and acid media, respectively. In addition, this electrocatalyst exhibits good stability and selectivity for the four-electron energy pathway while using lower metal loadings compared to commercial catalysts.

[Deep brain stimulation for Parkinson's disease: experience, benefits and limitations in a center in Latin America]. / Estimulación cerebral profunda para enfermedad de Parkinson: experiencia, beneficios y limitaciones en un centro en Latinoamérica.

Background: Parkinson's disease is poorly studied in Colombia. It is pharmacologically managed, but for refractory cases, surgery is a therapeutic option, positively impacting on quality of life. Objective: To determine the impact of deep brain stimulation as management in the control of progression in patients with Parkinson's disease attended our institution between the years 2014 to 2020. Method: Descriptive retrospective study, with patients collected between 2014 and 2020 undergoing deep brain stimulation surgery. The MDS-UPDRS (Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale) was applied in the pre- and postoperative period, and the results were compared. Results: 21 patients were included and the UPDRS was applied, finding a decrease in scores in the postoperative period. One patient had an operative site infection. Conclusions: There was an improvement in the MDS-UPDRS score, with a low rate of complications. The procedure time was prolonged from the preoperative evaluation. Deep brain stimulation is the management of choice for refractory Parkinson's disease. The patients in this series showed improvement in their symptoms. Unfortunately, there are limitations to perform this procedure in Colombia, such as the delay in the authorization of the procedure.

Antecedentes: La enfermedad de Parkinson está poco estudiada en Colombia. Es de manejo farmacológico, pero para casos refractarios la cirugía es una opción terapéutica que impacta positivamente en la calidad de vida. Objetivo: Determinar el impacto de la estimulación cerebral profunda como manejo en el control de la progresión en pacientes con enfermedad de Parkinson atendidos nuestra institución entre los años 2014 a 2020. Método: Estudio descriptivo de corte retrospectivo con pacientes recolectados entre los años 2014 y 2020 sometidos a cirugía de estimulación cerebral profunda. Se aplicó la MDS-UPDRS (Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale) en el pre- y el posoperatorio, y se compararon los resultados. Resultados: Se incluyeron 21 pacientes y se les aplicó la MDS-UPDRS, encontrando una disminución en las puntuaciones en el posoperatorio. Un paciente presentó infección del sitio operatorio. Conclusiones: Hubo mejoría en la puntuación de la MDS-UPDRS, con baja tasa de complicaciones. El tiempo de realización del procedimiento fue prolongado desde la valoración preoperatoria. La estimulación cerebral profunda es el manejo de elección para la enfermedad de Parkinson refractaria. Los pacientes de esta serie mostraron mejoría en sus síntomas. Desafortunadamente, existen limitaciones para la realización de este procedimiento en Colombia, como el retraso en la autorización del procedimiento.

Laparoscopic Hartmann's reversal has better clinical outcomes compared to open surgery: An international multicenter cohort study involving 502 patients.

Background: Hartmann's procedure (HP) is used in surgical emergencies such as colonic perforation and colonic obstruction. "Temporary" colostomy performed during HP is not always reversed in part due to potential morbidity and mortality associated with reversal. There are several contributing factors for patients requiring a permanent colostomy following HP. Therefore, there is still some discussion about which technique to use. The aim of this study was to evaluate perioperative variables of patients undergoing Hartmann's reversal using a laparoscopic and open approach. Methods: The multicenter retrospective cohort study was done between January 2009 and December 2019 at 14 institutions globally. Patients who underwent Hartmann's reversal laparoscopic (LS) and open (OS) approaches were evaluated and compared. Sociodemographic, preoperative, intraoperative variables, and surgical outcomes were analyzed. The main outcomes evaluated were 30-day mortality, length of stay, complications, and postoperative outcomes. Results: Five hundred and two patients (264 in the LS and 238 in the OS group) were included. The most prevalent sex was male in 53.7%, the most common indication was complicated diverticular disease in 69.9%, and 85% were American Society of Anesthesiologist (ASA) II-III. Intraoperative complications were noted in 5.3% and 3.4% in the LS and OS groups, respectively. Small bowel injuries were the most common intraoperative injury in 8.3%, with a higher incidence in the OS group compared with the LS group (12.2% vs. 4.9%, p < 0.5). Inadvertent injuries were more common in the small bowel (3%) in the LS group. A total of 17.2% in the OS versus 13.3% in the LS group required intensive care unit (ICU) admission (p = 0.2). The most frequent postoperative complication was ileus (12.6% in OS vs. 9.8% in LS group, p = 0.4)). Reintervention was required mainly in the OS group (15.5% vs. 5.3% in LS group, p < 0.5); mortality rate was 1%. Conclusions: Laparoscopic Hartmann's reversal is safe and feasible, associated with superior clinical outcomes compared with open surgery.

Establishing an acquisition and processing protocol for resting state networks with a 1.5 T scanner: A case series in a middle-income country.

OBJECTIVE: The aim of this study was to characterize the capability of detection of the resting state networks (RSNs) with functional magnetic resonance imaging (fMRI) in healthy subjects using a 1.5T scanner in a middle-income country. MATERIALS AND METHODS: Ten subjects underwent a complete blood-oxygen-level dependent imaging (BOLD) acquisition on a 1.5T scanner. For the imaging analysis, we used the spatial independent component analysis (sICA). We designed a computer tool for 1.5 T (or above) scanners for imaging processing. We used it to separate and delineate the different components of the RSNs of the BOLD signal. The sICA was also used to differentiate the RSNs from noise artifact generated by breathing and cardiac cycles. RESULTS: For each subject, 20 independent components (IC) were computed from the sICA (a total of 200 ICs). From these ICs, a spatial pattern consistent with RSNs was identified in 161 (80.5%). From the 161, 131 (65.5%) were fit for study. The networks that were found in all subjects were: the default mode network, the right executive control network, the medial visual network, and the cerebellar network. In 90% of the subjects, the left executive control network and the sensory/motor network were observed. The occipital visual network was present in 80% of the subjects. In 39 (19.5%) of the images, no any neural network was identified. CONCLUSIONS: Reproduction and differentiation of the most representative RSNs was achieved using a 1.5T scanner acquisitions and sICA processing of BOLD imaging in healthy subjects.

Utilidad de la angiografía por sustracción digital 3D en el abordaje endovascular de aneurismas cerebrales / Usefulness of 3D Digital Subtraction Angiography in the Endovascular Approach of Cerebral Aneurysms

Introducción: En el manejo de los aneurismas intracraneales la tendencia ha sido realizar procedimientos endovasculares mínimamente invasivos. Nuevas herramientas en imágenes, como la angiografía por sustracción digital en 3D (ASD 3D), sumadas a la experiencia de los radiólogos neurointervencionistas, han llevado a una mayor definición y precisión en el estudio del aneurisma intracraneal. Objetivo: Describir la utilidad de la técnica de angiografía por sustracción digital tridimensional para el abordaje pre y postembolización de los aneurismas intracraneales. Metodología: Estudio de corte transversal entre enero de 2016 y abril de 2017 en pacientes diagnosticados con aneurisma de arterias cerebrales, en el Hospital Infantil Universitario San José, en Bogotá, Colombia. Resultados: Se incluyeron 32 pacientes, de los cuales 71,8 % (n = 23) fueron mujeres. Entre los factores de riesgo para ruptura del aneurisma, el más frecuente fue edad mayor a 40 años (81,8 %). La localización más usual fue en la arteria cerebral media (ACM) derecha (30,3 %). Todos los casos correspondieron a aneurismas saculares. En el control angiográfico postembolización inmediato se evidenció que 16 casos (48,5 %) presentaron saco residual. Conclusiones: La realización de proyecciones multiplanares con reconstrucción angiográfica 3D brinda información adicional para una mejor caracterización del aneurisma y evaluación de las estructuras anatómicas adyacentes, por lo que es de gran utilidad para planear el procedimiento y para el seguimiento.

Introduction: The trend in management of intracranial aneurysms has shifted during the last decades to minimally invasive endovascular procedures. The usefulness of new imaging tools such as digital subtraction angiography in 3D (3D DSA), added to the experience of neurointerventional radiologists, have led to greater definition and accuracy in the study of intracranial aneurysms. Objective: To describe the usefulness of three-dimensional digital subtraction angiography for pre and post embolization approach of intracranial aneurysms. Methodology: A cross-sectional study between January 2016 and April 2017 in patients diagnosed with arterial cerebral aneurysms at the Hospital Infantil Universitario San José in Bogota, Colombia. Results: 32 patients were included, 71.8% (n = 23) were women. Among the risk factors for aneurysm rupture, the most frequent was age above 40 years (81.8%). The most frequent location was in the Right Middle Cerebral Artery (MCA) (30.3%). All cases corresponded to saccular aneurysms. In the immediate post-embolization angiographic control it was evidence that 16 cases (48.5%) presented residual sac. Conclusions: The realization of multiplanar projections with 3D angiographic reconstruction allows for a better characterization of the aneurysm and evaluation of the adjacent anatomical structures, being very useful for the planning of the procedure and in the follow-up.