606 research outputs found
Statistical tools for the improvement and optimization of electrochemical sensors
The response of electrochemical sensors for substance detection critically depends on the sensing potential, the value of which is often selected by the visual inspection of the sensor's response, as given by, for example, electrochemical methods like cyclic voltammetry (CV). Using experimental data from CV, we show how the selection of the sensing potential can affect the sensitivity and linear range of the measurements. Whenever the magnitude of the sensor's response is crucial, it can be better to optimize the sensor for its sensitivity; however, if the testing conditions involve a variable range of concentrations, with putative very small or high concentrations, a reliable response can be obtained if the sensor is optimized for the linear range.ITESO, A.C
Global characterization and target identification of piRNAs and endo-siRNAs in mouse gametes and zygotes
44 p.-1 tab.-10 fig.A set of small RNAs known as rasRNAs (repeat-associated small RNAs) have been related to the down-regulation of Transposable Elements (TEs) to safeguard genome integrity. Two key members of the rasRNAs group are piRNAs and endo-siRNAs. We have performed a comparative analysis of piRNAs and endo-siRNAs present in mouse oocytes, spermatozoa and zygotes, identified by deep sequencing and bioinformatic analysis. The detection of piRNAs and endo-siRNAs in the spermatozoa and revealed also in zygotes, hints to their potential delivery to oocytes during fertilization. However, a comparative assessment of the three cell types indicates that both piRNAs and endo-siRNAs are mainly maternally inherited. Finally, we have assessed the role of the different rasRNA molecules in connection with amplification processes by way of the "ping-pong cycle". Our results suggest that the ping-pong cycle can act on other rasRNAs, such as tRNA- and rRNA-derived fragments, thus not only being restricted to TEs during gametogenesis. © 2014 Elsevier B.V.This work was funded by grants from The European Chemical Industry Council Long-range Research Initiative (CEFIC-LRi), from the MEDDTL (11-MRESPNRPE-9-CVS-072), France, from the CSIC (PIE 201020E016), Spain.Peer reviewe
Efecto del ejercicio y la actividad física sobre las funciones ejecutivas en niños y en jóvenes. Una revisión sistemática
This qualitative systematic review tries to advance knowledge about the effect of physical activity on executive functions, paying special attention to healthy children, teenagers and youngsters. Several articles have been identified, categorized and analyzed in electronic databases such as ISI Web of Knowledge, SCOPUS, PubMed, SPORTDiscus, PsyINFO, ERIC, Google Scholar and Dialnet. According to the inclusion/exclusion criteria, following the PRISMA statement to record and categorize the results and throughout the quality assessment tool "The Effective Public Health Practice Project”, 44 pieces of research, structured in acute and chronic episodes of physical activity under two approaches: qualitative and quantitative, were chosen. The results show a higher number of experiments with quantitative acute episodes (45,45%) against qualitative ones (18,18%), chronic quantitative (20,45%) and chronic qualitative episodes (15,92%). The analysis of these investigations has allowed identifying the benefits of different types of physical activity studied on executive components.En la presente revisión sistemática cualitativa se intenta avanzar en el conocimiento sobre la incidencia de la actividad física sobre las funciones ejecutivas, focalizada en poblaciones sanas infantiles, adolescentes y jóvenes. Se identificaron, categorizaron y analizaron artículos de bases de datos electrónicas como ISI Web of Knowledge, SCOPUS, PubMed, SPORTDiscus, PsyINFO, ERIC, Google Scholar y Dialnet. Atendiendo a los criterios de inclusión/exclusión, siguiendo la declaración PRISMA para registrar y categorizar los resultados, y mediante la herramienta de evaluación de calidad “The Effective Public Health Practice Project”, se seleccionaron finalmente 44 investigaciones experimentales, estructuradas en episodios agudos y crónicos de actividad física bajo dos enfoques: cuantitativos y cualitativos. Los resultados muestran una superior cantidad de experimentos con episodios agudos cuantitativos (45,45%), frente a los agudos cualitativos (18,18%), crónicos cuantitativos (20,45%) y crónicos cualitativos (15,92%). Los análisis de estas investigaciones han permitido identificar los beneficios de los diferentes tipos de actividad física estudiados sobre los componentes ejecutivos
Efficacy of antiemetic therapy in patients undergoing laparoscopic cholecystectomy
AbstractIntroductionA high incidence of postoperative nausea and vomiting has been observed in patients undergoing laparoscopic cholecystectomy (20–40%). This causes an increase in patient discomfort, a delay in recovery, and an increase in hospital stay.ObjectiveCompare the efficacy of ondansetron plus metoclopramide and ondansetron alone in the control of postoperative nausea and vomiting in patients undergoing laparoscopic cholecystectomy.Material and methodsA comparative, prospective, experimental, longitudinal double blind study was performed with 30 patients programmed for laparoscopic cholecystectomy. The Apfel score was applied postoperatively. Patients were divided into two groups with 15 participants. Metoclopramide 10mg and ondansetron 4mg were administered in the first Group (A), and ondansetron 4mg in the second Group (B), after induction of anesthesia. Nausea and vomiting were evaluated for 24h postoperatively using a Likert scale.ResultsOf the patients who presented nausea, the condition was mild. The patient who presented vomiting, vomited only once. Neither group required rescue drugs. Regarding the Apfel score, there was no correlation between the percentage of stratified risk and the patients who presented postoperative nausea and vomiting.ConclusionsNo statistically significant difference was observed between ondansetron plus metoclopramide and ondansetron alone in patients subjected to laparoscopic cholecystectomy
Creatividad táctica y funciones ejecutivas en los deportes de interacción
Tactical creativity is one of the characteristics of the players with greater expertise in interactive (or contact) sports. The term is defined as the ability to generate original and surprising answers to the problems that arise during the game. Recent research has shown that these athletes have certain cognitive capacities, known as executive functions, which could explain this superiority. Experimental studies conducted with children conclude that the repeated practice of physical activity in environments with high levels of entropy could improve these executive functions. On the other hand, it has been seen that the use of intentional strategies by the coach, meant to address the behavior of athletes, can be detrimental to the development of tactical creativity. This review describes the evidence and offers a practical proposal on the design of learning environments promoting this capacity through the control of the task complexity and the feedback of the coach.La creatividad táctica es una de las características de los jugadores con mayor pericia en deportes de interacción. Ésta se define como la capacidad para generar respuestas sorpresivas y originales ante los problemas que surgen durante el juego. Recientes investigaciones han comprobado que estos deportistas poseen ciertas capacidades cognitivas, conocidas como funciones ejecutivas, que podrían explicar esta superioridad. Estudios experimentales llevados a cabo con niños concluyen que la práctica repetida de actividad física en entornos con elevados niveles de entropía podría mejorar estas funciones ejecutivas. Por otro lado, se ha visto que el uso de estrategias intencionales por parte del entrenador para dirigir la conducta de los deportistas puede ser perjudicial para el desarrollo de la creatividad táctica. En esta revisión se describe esta evidencia y se realiza una propuesta práctica sobre cómo diseñar entornos de aprendizaje para promover esta capacidad a través del control de la complejidad de la tarea y del feedback del entrenador
Local Anesthetics
The fascinating history of local anesthetics (LAs) began in South America with the herbal and traditional use of cocaine leaves by the indigenous peoples of Peru and Bolivia, the sacred plant of the Incas Erythroxylum coca. The use for anesthetic purposes dates back to 1884. Since then, the evolution of LAs has been closely related to research motivated by its efficacy and safety versus toxicity. According to their chemical structure, these drugs are classified into two main groups: esters and amino amides; however, there are three LAs with different characteristics: articaine, sameridine, and centbucridine. The pharmacological and toxic mode of action is primarily in the voltage-dependent sodium channels located in the cell membrane, which clinically produces analgesia, anesthesia, seizures, arrhythmias, and cardiac arrest. The quality of anesthesia and analgesia depends on the type of LA, dose, and application technique, while the deleterious effects are secondary to its plasma concentration. Nonanesthetic properties of LAs such as their antimicrobial, antineoplastic, antiarrhythmics, antitussive, and antiasthmatics effects have been described and are briefly reviewed
A research agenda on geoinformation sciences towards responsible land administration in Colombia
Landscape-scale drivers of glacial ecosystem change in the montane forests of the eastern Andean flank, Ecuador
Understanding the impact of landscape-scale disturbance events during the last glacial period is vital in accu- rately reconstructing the ecosystem dynamics of montane environments. Here, a sedimentary succession from the tropical montane cloud forest of the eastern Andean flank of Ecuador provides evidence of the role of non- climate drivers of vegetation change (volcanic events, fire regime and herbivory) during the late-Pleistocene. Multiproxy analysis (pollen, non-pollen palynomorphs, charcoal, geochemistry and carbon content) of the se- diments, radiocarbon dated to ca. 45–42 ka, provide a snap shot of the depositional environment, vegetation community and non-climate drivers of ecosystem dynamics. The geomorphology of the Vinillos study area, along with the organic‐carbon content, and aquatic remains suggest deposition took place near a valley floor in a swamp or shallow water environment. The pollen assemblage initially composed primarily of herbaceous types (Poaceae-Asteraceae-Solanaceae) is replaced by assemblages characterised by Andean forest taxa, (first Melastomataceae-Weinmannia-Ilex, and later, Alnus-Hedyosmum-Myrica). The pollen assemblages have no modern analogues in the tropical montane cloud forest of Ecuador. High micro-charcoal and rare macro-charcoal abundances co-occur with volcanic tephra deposits suggesting transportation from extra-local regions and that volcanic eruptions were an important source of ignition in the wider glacial landscape. The presence of the coprophilous fungi Sporormiella reveals the occurrence of herbivores in the glacial montane forest landscape. Pollen analysis indicates a stable regional vegetation community, with changes in vegetation population co- varying with large volcanic tephra deposits suggesting that the structure of glacial vegetation at Vinillos was driven by volcanic activity
Comparación entre el grado de regurgitación mitral detectada por ventriculografía nuclear y por ecocardiograma Doppler
Se estudiaron 18 pacientes con diagnóstico de insuficiencia mitral a quienes se les realizó una ventriculografía nuclear (basal y luego de 5 mg de nisoldipina oral) y un ecocadiograma Doppler con el propósito de validar un método radioisotópico para calcular el índice de regurgitación usando el análisis factorial. Mientras que la frecuencia cardíaca, el volumen telediastólico y el volumen sistólico no cambiaron significativamente posnisoldipina, la presión sanguínea, así como la fracción de eyección ventricular izquierda, el volumen telesistólico y el índice de regurgitación, disminuyeron significativamente (p < 0,05). Hubo una buena concordancia (78 %; Kappa = 0,66) entre la valoración de la severidad de la insuficiencia mitral por ventriculografía nuclear y por eco Doppler, mientras que al comparar los resultados de la evaluación clínica con la ventriculografía nuclear, la concordancia fue moderada (67 %; kappa = 0,48). Se concluye que el cálculo del índice de regurgitación por análisis factorial en una ventriculografía nuclear, constituye un método no invasivo adecuado para la evaluación semicuantitativa de la severidad de la insuficiencia mitral
- …