Muestreadores pasivos en el estudio de la dinámica de plaguicidas y el impacto ambiental en el agua

RESUMEN: Los plaguicidas son las sustancias con mayor aplicación en la agricultura las cuales pueden contaminar los cuerpos de agua por descarga directa o indirecta, pero los grandes volúmenes y los procesos transformación pueden disminuir la concentración de estas sustancias y sus productos de degradación en las cuencas. Actualmente, los métodos convencionales de extracción tales como: la extracción en fase sólida (SPE) y la micro extracción en fase sólida (SPME) entre otras, no permiten bajos límites de detección, sin embargo bajos niveles de pesticidas y productos de degradación podrían producir toxicidad crónica en diferentes especies. Actualmente el muestreo pasivo es ampliamente usado en el monitoreo de plaguicidas y para el aseguramiento de la calidad del agua debido a que esta metodología es aplicada in estudios de bioacumulación y deteccion a partes por cuatrillón (ppq). Las membranas con mayor uso en el muestreo pasivo son las membranas tipo SPMD (Semi-permeable membrane devices), las cuales permiten la concentración de sustancias lipofílicas y las membranas tipo POCIS (Polar organic chemistry integrative sampler), las cuales permiten concentrar sustancias hidrofílicas. Esta revisión cubre la aplicación de los muestreadores pasivos en el análisis de plaguicidas, en los estudios de biacumulación y en la evaluación de los riesgos ecotoxicológicos. Finalmente los muestreadores pasivos permiten reducir costos, el tiempo de concentración y la cantidad de solventes orgánicos empleados en el tratamiento de muestra, lo que conduce a su clasificación dentro de las tendencias de la “química analítica verde”.ABSTRACT: Pesticides are the most applied substances in agricultural activities which can contaminate water bodies by direct or indirect discharge, but large volumes and natural transformation processes can decrease the concentration of these substances and their degradates in watershed. Currently, conventional extraction methods such as: solid phase extraction (SPE) and solid phase micro extraction (SPME) among others do not permit low detection limits. However low levels of pesticides and degradates could produce chronic toxicity in different species. Nowadays, passive sampling is widespread used for monitoring pesticides and for ensuring the water quality and bioaccumulation studies due to this methodology allows the detection of pollutant from parts per quadrillion (ppq). The most popular membranes used in passive sampling are the semipermeable membrane devices (SPMD), which permit the concentration of lipophilic substances and the polar organic chemical integrative sampler (POCIS), which permits concentration of the hydrophilic ones. This review is about the application of passive samplers in pesticides analysis, the importance of these devices in the bioaccumulation studies and the evaluation of the ecotoxicological risks. Finally, passive sampling allows reducing costs, time and the amount of organic solvent used which classifies it within the environmental trends of “green analytical chemistry”

Importancia de las redes neuronales artificiales en la ingeniería civil: una revisión sistemática de la literatura

Las redes neuronales artificiales (RNA) tienen un papel relevante en la actualidad, diversas áreas aplican esta técnica por las ventajas que presentan para resolver problemas complejos con muchas restricciones en comparación con los métodos tradicionales, que están quedando desfasados. Se conoce muy poco acerca de esta técnica y su aplicación en distintas ramas de la Ingeniería Civil. Por tal motivo, la presente investigación tiene por objetivo realizar una revisión sistemática de la literatura para identificar el uso de esta técnica y determinar los resultados de la aplicación de modelos de RNA en la ingeniería civil. Se incluyeron un total de 41 artículos científicos que se distribuyen de la siguiente forma: 6 en Scopus, 1 en ScienceDirect, 23 en ProQuest, 7 en Google Académico, 2 en Dialnet, 2 en SciELO. Se encontró que las RNA son utilizadas para predecir o pronosticar variables asociadas a los campos de estudio de la ingeniería civil, se hallaron 8 aplicaciones de RNA para propiedades del concreto, 11 para propiedades del suelo, 5 para análisis sísmico, 9 para hidráulica, 7 para valorización de inmuebles y 1 para diseño de puentes. Así mismo se encontró que el Perceptrón Multicapa es el modelo de RNA más utilizada, logrando en promedio un R2 de 0.99, lo que demuestra ventajas para resolver problemas con precisión, en tiempos más cortos, con datos faltantes en los conjuntos de datos, así como la reducción del factor de error.Artificial neural networks (ANN) have a relevant role nowadays; several areas apply this technique due to the advantages they have to solve complex problems with many constraints compared to traditional methods, which are becoming outdated. Very little is known about this technique and its application in different branches of Civil Engineering. For this reason, the present research aims to conduct a systematic review of the literature to identify the use of this technique and to determine the results of the application of ANN models in civil engineering. A total of 41 scientific articles were included, distributed as follows: 6 in Scopus, 1 in ScienceDirect, 23 in ProQuest, 7 in Google Scholar, 2 in DialNet, 2 in SciELO. It was found that ANNs are used to predict or forecast variables associated with the fields of study in civil engineering; 8 applications of ANN were found for concrete properties, 11 for soil properties, 5 for seismic analysis, 9 for hydraulics, 7 for real estate valuation and 1 for bridge design. Likewise, it was found that the multilayer Perceptron is the most used ANN model, achieving an average R2 of 0.99, which shows advantages to solve problems with precision, in shorter times, with missing data in the data sets, as well as the reduction of the error factor

Decerebration induced by surgical transection of cerebral ganglion of crayfish

Background: Since the neural structures of the crayfish brain closely resemble their equivalent in the mammals. This can be suggested by observing the similarity that exists in the brain divided by the surgical transection of the crayfish brain in which the protocerebrum remains attached to the first two cranial nerves, findings also described by Frederic Bremer in 1935 in cats with cerebral transection.Methods: Total 11 Adult male crayfish were trained to respond with defense reflex, the animals were placed in water at 0°C, remained without any movement, and subsequently through a small incision of 3 mm in diameter in the medial antero region and dorsal cephalothorax region, a surgical section of the cerebral ganglion was performed. Immediately after surgery, metal microelectrodes were implanted to collect the activity of the photoreceptors and visual fibers.Results: Once the defense reflex begins to recover in previously decerebrated crayfish, it means that it shows signs of reconnection. The isolated protocerebrum with the deutocerebrum olfactory lobe remain alive for several days and the neuronal connections were reestablished, as measured throughout the bilateral defense activity. The defense reflex was observed in all animals and then recovered after surgery.Conclusions: The crayfish is an excellent model to work the visual activity, all coding of visual information was suppressed in de-cerebrated crayfish. The recovery of the neural disconnection is observed from 40 days, where the defence reflex appears again before visual stimuli.

Outcomes of off-label drug uses in hospitals: a multicentric prospective study

Purpose: The study aims to assess the clinical evidence, outcome and cost of off-label use of medicines in the hospital setting. Methods: A multicentric prospective cohort study of patients treated with off-label medicines was carried out in five tertiary hospitals from May 2011 to May 2012. Information on clinical characteristics of patients, drugs, outcomes and costs was collected. Patients were followed up to 6 months, and information was assessed by reviewing clinical records and interviewing physicians. Results: A total of 226 patients were included. The median (interquartile range (IQR)) age of patients was 46 (3362) years; 59 % were women. Patients had received a median of three previous treatments, and a lack of response (or suboptimal) was the main reason for off-label use (72.1 %). A total of 232 off-label medicines were administered for 102 different indications. The most frequent medicines were rituximab (49; 21.1 %), botulinum toxin (25; 10.7 %) and omalizumab (14; 6.0 %). In 117 (51.8 %) cases, the level of clinical evidence for their use was low. A partial clinical response was observed in 82 patients (36.3 %), complete response in 71 (31.4 %) and stabilization in 11 (4.9 %). A total of 58 (26.5 %) patients had adverse effects, which in 11 (4.9 %) were severe. The median (IQR) cost per patient was 2,943.07 (541.95,872.54). Conclusions: There was a high variability of off-label medicines and indications. Although the clinical evidence of off-label medicines was often low, clinical response was observed in many patients with previous multiple treatment failure, but at the expense of some adverse effects and a high cost. Registers of patients would be helpful for clinical decisions, although clinical trials are needed

Outcomes of off-label drug uses in hospitals : a multicentric prospective study

Altres ajuts: We would to thank the Spanish Ministry of Health, Social Affairs and Equality for their financial support given though a grant from the scholarship EC-206 in the public call for the promotion of independent clinical research (SAS/2370/2010 order of September 27)The study aims to assess the clinical evidence, outcome and cost of off-label use of medicines in the hospital setting. A multicentric prospective cohort study of patients treated with off-label medicines was carried out in five tertiary hospitals from May 2011 to May 2012. Information on clinical characteristics of patients, drugs, outcomes and costs was collected. Patients were followed up to 6 months, and information was assessed by reviewing clinical records and interviewing physicians. A total of 226 patients were included. The median (interquartile range (IQR)) age of patients was 46 (33-62) years; 59 % were women. Patients had received a median of three previous treatments, and a lack of response (or suboptimal) was the main reason for off-label use (72.1 %). A total of 232 off-label medicines were administered for 102 different indications. The most frequent medicines were rituximab (49; 21.1 %), botulinum toxin (25; 10.7 %) and omalizumab (14; 6.0 %). In 117 (51.8 %) cases, the level of clinical evidence for their use was low. A partial clinical response was observed in 82 patients (36.3 %), complete response in 71 (31.4 %) and stabilization in 11 (4.9 %). A total of 58 (26.5 %) patients had adverse effects, which in 11 (4.9 %) were severe. The median (IQR) cost per patient was €2,943.07 (541.9-5,872.54). There was a high variability of off-label medicines and indications. Although the clinical evidence of off-label medicines was often low, clinical response was observed in many patients with previous multiple treatment failure, but at the expense of some adverse effects and a high cost. Registers of patients would be helpful for clinical decisions, although clinical trials are needed. The online version of this article (doi:10.1007/s00228-014-1746-2) contains supplementary material, which is available to authorized users

Microsurgery in complex trauma of pelvic limb in a pediatric patient: case report

Complex trauma is defined as the condition secondary to the exchange of kinetic energy of two or more tissues in one limb. This entity is a surgical emergency that can have many sequelae and can even result in limb loss. An 11-year-old female patient presents complex pelvic limb trauma secondary to contuse injury caused by a helicopter’s rotor blades.  Pelvic limb reconstruction was performed with iliac crest bone graft, the fracture was stabilized with an external fixator and the skin defect was covered with an anterolateral microvascular thigh flap (ALT). There was an adequate integration of the bone graft with adequate skin coverage thanks to the ALT thigh flap. The patient presented discreet limb shortening as consequence.  Currently, microsurgery is the only medical option that meets the objectives of limb reconstruction. Microsurgical techniques can be used in pediatric and adult patients. The success of any recovery from complex trauma is vigorous surgical cleaning, avoiding sequential and/or multiple washes

Thoracic limb salvage by fibular free flap

The treatment of most fractures of the ulna and radius is usually performed by anatomical reduction and internal fixation, when damage is extensive and local soft tissue cannot provide a complete wound coverage, locoregional flaps present a suitable reconstructive benefit. A 35-year-old male patient suffered an exposed diaphysio-metaphyseal fracture with multi-fragmented distal radius. The patient was evaluated during a 10-day period at the National Institute of Rehabilitation, where the osteosynthesis material and a severe infectious process with necrosis were identified. Necrosectomy of the posterior compartment and removal of the osteosynthesis material was performed, a skin defect of approximately 22x16 cm was observed with a bone gap of 6 cm of radius and ulna. a fibula-free flap is placed to correct the skin defect and an external fixative used for bone alignment. The fibular free flap presents an excellent therapeutic alternative in the resolution of bone gaps with extensive skin defect. Whenever a trained microsurgery team is available, current scales of limb injury should be considered but not utilized for therapeutic approach, always trying to shift amputation as the first option, to the very last one of them

Endodontic regenerative treatment for internal radicular resorption using bio-ceramic material, case report

The internal resorption of the internal radicular conduct is a process than can be both physiological or pathological, being the osteoclasts, odontoclasts and dentinoclast responsible for said process. 49-year-old female patient, refers orthodontic treatment at age 20, attends a dental check-up due to pain when chewing. Dental organ (DO) #11 was diagnosed with internal root resorption and symptomatic, suppurative apical periodontitis. Treatment started performing an endodontic access and taking a conductometry reading with an apical foramen locator, using a precision hybrid instrumentation technique and applying hypochlorite irrigation, the intra-canal was medicated with chemically pure calcium hydroxide for 7 days. The canal obturation was repaired infiltrating a bio-ceramic material (BIO-C Sealer) followed by the placement of the single cone using a vertical condensation technique

Jornada del Día Internacional del Derecho a Saber 2021

International Day for Universal Access to Informatio