Obtención y caracterización de materiales adsorbentes a partir de cascarilla de arroz

Agricultural waste management for the production of materials with specific uses is important for the remediation of certain environmental problems. Rice husk, an abundantly agricultural waste in Colombia, could be a low cost adsorbent for molecules such as dyes or heavy metals in effluent streams. In this research, we address the production and characterization of rice husk ash obtained by chemical activation with phosphoric acid as an adsorbent material. The physical-chemical properties of the materials were evaluated using different characterization techniques, such as close analysis, iodine number, adsorption of methylene blue, adsorption-desorption of nitrogen, analysis of the functional groups on the surface of the adsorbent through infrared spectroscopy (ftir), as well as an analysis of the morphology with scanning electron microscopy (sem). The materials have a surface area around 320 m2/g, which decreases depending on the amount of acid used in the activation. The pore size in the studied samples ranged between 4 and 12 nm, which suggest that mesoporous solids were obtained. Regarding the adsorption of methylene blue, results show that the production of the activated ashes from rice husk as adsorbent materials is viable, presenting a new opportunity for the use of materials considered as agricultural waste.La utilización de residuos agroindustriales para la producción de materiales con cualidades específicas es de importancia para solucionar algunos problemas ambientales. La cascarilla de arroz, un desecho agrícola abundante en Colombia, podría ser utilizada como un adsorbente de bajo costo para moléculas como colorantes o metales pesados ​​presentes en las corrientes de efluentes. Este trabajo de investigación presenta la obtención y caracterización de materiales adsorbentes a partir de cascarilla de arroz, producidos mediante activación química con ácido fosfórico. Las propiedades físico-químicas de los materiales fueron evaluadas por medio de diferentes técnicas de caracterización que incluyeron análisis próximo, determinación del número de yodo, adsorción de azul de metileno, adsorción-desorción de nitrógeno, análisis de los grupos funcionales presentes en la superficie del adsorbente a través de la espectroscopia de infrarrojo (ftir), así como un análisis de la morfología de las cenizas mediante microscopia electrónica de barrido (sem). Los resultados indican que las cenizas producidas tienen un área superficial aproximada de 320 m2/g, la cual disminuye directamente dependiendo de la cantidad de ácido usado en la activación. Los tamaños de poro de las muestras trabajadas oscilan entre 4 y 12 nm, lo cual indica que se obtuvieron sólidos mesoporosos. Respecto a la capacidad de adsorción, los resultados muestran que el proceso de producción de las cenizas activadas a partir de cascarilla de arroz como materiales adsorbentes es viable, mostrando así una nueva oportunidad de aprovechamiento para los materiales considerados como desechos agrícolas

Utilizando la estadística como herramienta para el análisis de la situación sociocultural, y laboral de alumnos pertenecientes al nivel polimodal de escuelas técnicas, de la provincia de Tucumán y de sus respectivas familias

En el marco de la convocatoria desde la Secretaria de Políticas Universitarias del Ministerio de Educación Ciencia y Tecnología de la República Argentina para realizar proyectos cuya meta el Apoyo a las Escuelas Medias, se presentó desde la Facultad Regional Tucumán – Universidad Tecnológica Nacional, el proyecto “Desarrollo de un Sistema de Vinculación e Innovación para Mejorar la Relación entre la Propuesta Educativa de la Escuela Media, y el Mundo del Trabajo en las Comunidades de Inserción de las Instituciones Involucradas”. Para obtener información sobre la comunidad educativa involucrada en el Proyecto, se decidió diseñar diferentes encuestas a ser aplicadas a los alumnos, docentes , graduados y directivos. Este trabajo aporta, entonces, una descripción de los resultados obtenidos en la encuesta aplicada a los alumnos de las diferentes escuelas participantes en el Proyecto

Polymethylferrocene-induced photopolymerization of cyanoacrylates using visible and near-infrared light

Metallocene-induced photopolymerization of cyanoacrylates based on electron transfer processes has been proposed as an alternative to more conventional light-curing strategies relying on photobase generators. However, successful application of this methodology has so far only been achieved for very reactive cyanoacrylates under UV illumination and long irradiation times, which eventually hampers its practical use. To overcome these limitations, we describe in this work the use of electron-rich polymethylferrocenes as photoinitiators, with which fast light-induced polymerization of commercial formulations of less reactive, but more relevant long alkyl chain cyanoacrylates has been accomplished by illumination with visible and even near-infrared light. In addition, generalization of this technology to other electron-deficient, noncyanoacrylate monomers has been demonstrated. The low oxidation potential of polymethylferrocenes accounts for these excellent results, which strongly favors the formation of radical anions by electron transfer that initiate the polymerization reaction. Because of the high molecular weight and superior adhesive behavior of the resulting polymer materials as well as the facile access to polymethylferrocenes, they emerge as very attractive photoinitiators for the light-curing of cyanoacrylate (and other) glues in real applications

Carotid artery stenting in a single center, single operator, single type of device and 15 years of follow-up

Background: Revascularization with carotid stent (CAS) is considered the therapeutic alternative to endarterectomy (CEA). However, its role compared to CEA remains questioned, mainly due of the heterogeneity of long-term results. The objective of this study was to report the efficacy and durability of CAS in terms of stroke prevention in a “real world experience”. Method: This was a single-center retrospective analysis of 344 patients treated with CAS between January 2001 and December 2015. The primary outcome of the trial was stroke, myocardial infarction, or death during a periprocedural period or any stroke event over a 15-year follow-up. The secondary aim was to identify risk factors for 30-day complications, long-term neurological complications, and intra-stent restenosis. Results: The primary composite end point (any stroke, myocardial infarction, or death during the periprocedural period) was 2.3%. The use of an EPD was protective against major complications. Long-term follow-up was achieved in 294 patients (85,5%) with a median of 50 months (range 0-155 months). Fifty-six (16,3%) died within this period, most commonly of nonvascular causes (4 patients had stroke-related deaths). During the follow-up period, 8 strokes and 3 TIAs were diagnosed (3.2%). ISR determined by sequential ultrasound was assessed in 4.4% of the patients and remained asymptomatic in all but 2 patients (0.6%). All patients with restenosis underwent revascularization with balloon angioplasty. Conclusion: The long-term follow-up results of our study validate CAS as a safe and durable procedure with which to prevent ipsilateral stroke, with an acceptable rate of restenosis, recurrence and mortality

Surveillance of Salmonella enterica serovar Typhi in Colombia, 2012-2015.

Salmonella Typhi (S. Typhi) is the causative agent of typhoid fever; a systemic disease affecting ~20 million people per year globally. There are little data regarding the contemporary epidemiology of typhoid in Latin America. Consequently, we aimed to describe some recent epidemiological aspects of typhoid in Colombia using cases reported to the National Public Health Surveillance System (Sivigila) between 2012 and 2015. Over the four-year reporting period there were 836 culture confirmed cases of typhoid in Colombia, with the majority (676/836; 80.1%) of reported cases originated from only seven departments. We further characterized 402 S. Typhi isolates with available corresponding data recovered from various departments of Colombia through antimicrobial susceptibility testing and molecular subtyping. The majority (235/402; 58.5%) of these typhoid cases occurred in males and were most commonly reported in those aged between 10 and 29 years (218/402; 54.2%); there were three (0.74%) reported fatalities. The overwhelming preponderance (339/402; 84.3%) of S. Typhi were susceptible to all tested antimicrobials. The most common antimicrobial to which the organisms exhibited non-susceptibility was ampicillin (30/402;7.5%), followed by nalidixic acid (23/402, 5.7%). Molecular subtyping identified substantial genetic diversity, which was well distributed across the country. Despite the diffuse pattern of S. Typhi genotypes, we identified various geographical hotspots of disease associated with local dominant genotypes. Notably, we found limited overlap of Colombian genotypes with organisms reported in other Latin American countries. Our work highlights a substantial burden of typhoid in Colombia, characterized by sustained transmission in some regions and limited epidemics in other departments. The disease is widely distributed across the country and associated with multiple antimicrobial susceptible genotypes that appear to be restricted to Colombia. This study provides a current perspective for typhoid in Latin America and highlights the importance of pathogen-specific surveillance to add insight into the limited epidemiology of typhoid in this region

Glutaminase and MMP-9 downregulation in cortex and hippocampus of LPA1 receptor null mice correlate with altered dendritic spine plasticity

Lysophosphatidic acid (LPA) is an extracellular lipid mediator that regulates nervous system development and functions acting through G protein-coupled receptors (GPCRs). Here we explore the crosstalk between LPA1 receptor and glutamatergic transmission by examining expression of glutaminase (GA) isoforms in different brain areas isolated from wild-type (WT) and KOLPA1 mice. Silencing of LPA1 receptor induced a severe down-regulation of Gls-encoded long glutaminase protein variant (KGA) (glutaminase gene encoding the kidney-type isoforms, GLS) protein expression in several brain regions, particularly in brain cortex and hippocampus. Immunohistochemical assessment of protein levels for the second type of glutaminase (GA) isoform, glutaminase gene encoding the liver-type isoforms (GLS2), did not detect substantial differences with regard to WT animals. The regional mRNA levels of GLS were determined by real time RT-PCR and did not show significant variations, except for prefrontal and motor cortex values which clearly diminished in KO mice. Total GA activity was also significantly reduced in prefrontal and motor cortex, but remained essentially unchanged in the hippocampus and rest of brain regions examined, suggesting activation of genetic compensatory mechanisms and/or post-translational modifications to compensate for KGA protein deficit. Remarkably, Golgi staining of hippocampal regions showed an altered morphology of glutamatergic pyramidal cells dendritic spines towards a less mature filopodia-like phenotype, as compared with WT littermates. This structural change correlated with a strong decrease of active matrix-metalloproteinase (MMP) 9 in cerebral cortex and hippocampus of KOLPA1 mice. Taken together, these results demonstrate that LPA signaling through LPA1 influence expression of the main isoenzyme of glutamate biosynthesis with strong repercussions on dendritic spines maturation, which may partially explain the cognitive and learning defects previously reported for this colony of KOLPA1 mice

Efectividad de la analgesia anticipatoria con morfina epidural en la cirugía torácica electiva

Introduction: Postoperative pain has an acute nature. Its origin is the result of nociceptive stimulation due to the aggression caused by the surgery. Objectives: To compare the effectiveness of analgesia with preemptive and postoperative epidural morphine in the treatment of acute postoperative pain in elective thoracotomy. Method: A quasi-experimental study to compare the effectiveness of preemptive and postoperative analgesia with epidural morphine 4mg in the management of pain associated to elective thoracotomy was conducted at the Arnaldo Milian Castro Provincial University Hospital in Santa Clara from January 2006 to January 2009. The study included 62 patients who were surgically intervened. They were divided into two groups. Both groups received thoracic epidural analgesia with lyophilized morphine 4mg , one pre-emptively and postoperatively the other. With the patient's informed consent, the mean arterial pressure, heart rate and pain intensity (by means of the visual analogue scale) were recorded at 8 times in the first 24 hours after surgery. Results: A significant decrease of the intensity of postoperative pain was achieved in the group of patients that received the preemptive analgesia, with a reduction of the need of rescue analgesia and improved postoperative satisfaction. There were no hemodynamic changes or significant adverse effects in both analgesic modalities. Conclusions: analgesia with morphine, both preemptive and postoperative, is effective in controlling postoperative pain in this kind of procedures; however, it was demonstrated that preemptive analgesia is more effective in this type of surgery.Introducción: El dolor postoperatorio tiene un carácter agudo. Su origen es el resultado de la estimulación nociceptiva debida a la agresión producida por el acto quirúrgico. Objetivos: Comparar la efectividad de la analgesia con morfina epidural anticipatoria y postoperatoria, en el tratamiento del dolor agudo postoperatorio por toracotomía electiva. Método: Se realizó un estudio cuasiexperimental, para comparar la efectividad de la analgesia con morfina 4mg epidural Anticipatoria y Postoperatoria, en el tratamiento del dolor en la cirugía torácica electiva, realizado en el Hospital Universitario Docente “Arnaldo Milián Castro”, de Santa Clara, de enero de 2006 a enero de 2009 en 62 pacientes intervenidos quirúrgicamente divididos en dos grupos; a ambos se le aplicó analgesia epidural torácica con morfina liofilizada 4mg, en un grupo anticipatorio y en el otro postoperatorio. Previo consentimiento informado, se registró: tensión arterial media, frecuencia cardiaca, e intensidad del dolor según escala analógica visual en ocho momentos de las primeras 24 horas del postoperatorio. Resultados: En el grupo de pacientes con analgesia anticipatoria se obtuvo decrecimiento significativo de la intensidad del dolor postoperatorio con menores requerimientos de analgesia de rescate y una mejor satisfacción postoperatoria. No se presentaron variaciones hemodinámicas, ni efectos adversos importantes en ambas modalidades analgésicas. Conclusiones: La analgesia con morfina, tanto anticipatoria como postoperatoria, es efectiva para el control del dolor postoperatorio en este tipo de procedimiento, no obstante se demostró que la analgesia anticipatoria es más efectiva

The Response to Biologics is Better in Patients with Severe Asthma Than in Patients with Asthma–COPD Overlap Syndrome

Although biologics have demonstrated to be effective in T2-high asthma patients, there is little experience with these drugs in asthma-COPD overlap (ACO). The aim of this study was to compare the effectiveness of biologics in these two conditions. We included 318 patients (24 ACO and 297 asthma) treated with monoclonal antibodies and followed for at least 12 months Omalizumab was the most frequently employed biologic agent both in patients with ACO and asthma. Asthma control test (ACT) scores after at least 12 months of biologic therapy were not significantly different between groups. The percentage of patients with >= 1 exacerbation and >= 1 corticosteroid burst was significantly higher in ACO patients (70.8 vs 27.3 and 83.3% vs 37.5%, respectively), whereas the percentage of controlled patients (with no exacerbations, no need for corticosteroids and ACT >= 20) was significantly lower (16.7% vs 39.7%). In conclusion, this report suggests that patients with ACO treated with biologics reach worse outcomes than asthma patients