Extra-sístoles ventriculares: quando e como tratá-las

Iniciar o tratamento com antiarrítmicos em portadores de extra-sístoles ventriculares pode ser uma questao bem difícil, algumas vezes polêmica, dependendo das circunstâncias. Os batimentos ectópicos ventriculares prematuros sao a manifestaçao mais comum dos distúrbios do ritmo cardíaco, surgindo freqüentemente em pessoas sadias. Esta decisao deve-se basear na presença de sintomas limitantes, alteraçoes estruturais cardíacas e comprometimento da funçao contrátil ventricular. Os mecanismos eletrofisiológicos responsáveis pelo aparecimento das contraçoes ventriculares precoces sao: parasistolia, reentrada e atividade deflagrada. Cada um deles apresenta características definidas, tanto na sua demonstraçao experimental, como na sua exteriorizaçao eletrocardiográfica. A investigaçao completa do paciente com extra-sístoles ventriculares compreende: história clínica, exame físico, eletrocardiograma (em repouso, ambulatorial e durante esforço), ecocardiograma, radioisótopos, ressonância magnética e eletrocardiografia de alta resoluçao. Raramente, utiliza-se: cineangiocoronariografia, cineventriculografia e estudo eletrofisiológico intracardíaco. Serao medicados com antiarrítmicos somente os casos com lesao cardíaca evidente. Incluem-se nesta situaçao: determinadas cardiopatias congênitas, valvopatias, miocardiopatias e insuficiência coronária (aguda ou crônica). Existindo grande risco de morte súbita e sendo a arritmia cardíaca refratária, há necessidade do emprego de métodos terapêuticos nao farmacológicos. Os principais medicamentos antiarrítmicos recomendados sao: amiodarona, propafenona, sotalol, quinidina, procainamida, mexiletine, disopiramida, flecainida, verapamil e difenil-hidantoína. A lidocaína é a única medicaçao exclusivamente de uso parenteral. O emprego destes fármacos pode provocar o aparecimento de novos distúrbios do ritmo ou agravamento das alteraçoes pré-existentes, principalmente quando a funçao ventricular encontra-se gravemente comprometida. Portanto, deve-se prescrever apropriadamente os antiarrítmicos, identificar as condiçoes clínicas do seu aparecimento e evitar, tanto quanto possível, associaçoes de medicamentos

Aproximación a la producción secundaria de anacroneuria (plecoptera: perlidae), en la parte media del río Gaira (hacienda la victoria)

Dentro de los insectos acuáticos el orden Plecoptera, se constituye en un componente importante de la entomofauna de ecosistemas dulceacuícolas en términos de abundancia, diversidad y distribución. Cumplen un rol destacado en la descomposición y recirculación de nutrientes, además de contribuir en la red trófica como alimento de otros insectos y vertebrados. El propósito del estudio fue realizar una aproximación a la producción secundaria, a partir de la medición de la biomasa y las tallas de individuos del género Anacroneuria colectado durante cuatro meses en tres coriotopos en la parte media del río Gaira (Serranía de San Lorenzo, Sierra Nevada de Santa Marta). Adicionalmente se describieron las dietas, para identificar posibles diferencias en el contenido estomacal de las distintas tallas. Se colectaron en total 1230 individuos, de seis morfo especies A. sp. U, A. sp. V, A. sp. W, A. sp. X, A. sp. Y, A. sp. Z. Los individuos se clasificaron en cinco tallas, según la relación ancho de la cabeza (mm) Vs longitud total (mm) y ancho de la cabeza (mm) Vs peso seco (mg). Se encontraron diferencias en la distribución de las tallas entre muestreos, pero no entre coriotopos. Existen diferencias significativas en el número de individuos entre las tallas, y entre los diferentes coriotopos siendo la hojarasca el de mayores abundancias (763) y el de menor (86) piedra. La biomasa total media fue 0.0978 mg*rn-2, las tallas intermedias fueron las que más contribuyeron a este valor. La producción total fue 0.02962 mg*m-2d-1, observándose que las tallas pequeñas e intermedias son la que sustentan la producción. No se encontró relación entre el contenido estomacal y las tallas, los restos vegetales y los detritos fueron los más frecuentes

Aerosol radiative forcing during African desert dust events (2005–2010) over Southeastern Spain

The daily (24 h) averages of the aerosol radiative forcing (ARF) at the surface and the top of the atmosphere (TOA) were calculated during desert dust events over Granada (southeastern Spain) from 2005 to 2010. A radiative transfer model (SBDART) was utilized to simulate the solar irradiance values (0.31–2.8 μm) at the surface and TOA, using as input aerosol properties retrieved from CIMEL sun photometer measurements via an inversion methodology that uses the sky radiance measurements in principal plane configuration and a spheroid particle shape approximation. This inversion methodology was checked by means of simulated data from aerosol models, and the derived aerosol properties were satisfactorily compared against well-known AERONET products. Good agreement was found over a common spectral interval (0.2–4.0 μm) between the simulated SBDART global irradiances at surface and those provided by AERONET. In addition, simulated SBDART solar global irradiances at the surface have been successfully validated against CM-11 pyranometer measurements. The comparison indicates that the radiative transfer model slightly overestimates (mean bias of 3%) the experimental solar global irradiance. These results show that the aerosol optical properties used to estimate ARF represent appropriately the aerosol properties observed during desert dust outbreak over the study area. The ARF mean monthly values computed during desert dust events ranged from −13 ± 8 W m−2 to −34 ± 15 W m−2 at surface, from −4 ± 3 W m−2 to −13 ± 7 W m−2 at TOA and from +6 ± 4 to +21 ± 12 W m−2 in the atmosphere. We have checked if the differences found in aerosol optical properties among desert dust sectors translate to differences in ARF. The mean ARF at surface (TOA) were −20 ± 12 (−5 ± 5) W m−2, −21 ± 9 (−7 ± 5) W m−2 and −18 ± 9 (−6 ± 5) W m−2 for sector A (northern Morocco; northwestern Algeria), sector B (western Sahara, northwestern Mauritania and southwestern Algeria), and sector C (eastern Algeria, Tunisia), respectively. The Kolmogorov-Smirnov statistical test revealed that daily {ARF} values at TOA for sector A were significantly different from the other two sectors, likely as a result of the lower values of single scattering albedo obtained for sector A. The mean values of aerosol radiative forcing efficiency at surface (TOA) were −74 ± 12 W m−2 (−17 ± 7 W m−2) for sector A, −70 ± 14 W m−2 (−20 ± 9 W m−2) for sector B, and −65 ± 16 W m−2 (−22 ± 10 W m−2) for sector C, and thus comparable between the three sectors in all seasons.This work was supported by the Andalusia Regional Government through projects P08-RNM-3568 and P10-RNM-6299, by the Spanish Ministry of Science and Technology through projects CGL2010-18782, CSD2007-00067 and CGL2011-13580-E/CLI; and by EU through ACTRIS project (EU INFRA-2010-1.1.16-262254). The authors thankfully acknowledge the computer resources, technical expertise and assistance provided by the Barcelona Supercomputing Center. ALFA database computation was partly supported by RES (Spanish Supercomputation Network) computing resources (projects AECT-2009-1-0012, AECT-2011-3-0016)

Image Signal Processor parameter tuning with surrogate-assisted Particle Swarm Optimization

International audienceEvolutionary algorithms (EA) are developed and compared based on well defined benchmark problems, but their application to real-world problems is still challenging. In image processing, EA have been used to tune a particular image filter or in the design of filters themselves. But nowadays in digital cameras, the image sensor captures a raw image that is then processed by an Image Signal Processor (ISP) where several transformations or filters are sequentially applied in order to enhance the final picture. Each of these steps have several parameters and their tuning require lot of resources that are usually performed by human experts based on metrics to assess the quality of the final image. This can be considered as an expensive black-box optimization problem with many parameters and many quality metrics. In this paper, we investigate the use of EA in the context of ISP parameter tuning with the aim of raw image enhancement

Determinación de la persistencia de compuestos perfluorinados en plantas de tratamiento de aguas residuales municipales mediante LC-MS/MS

Perfluorinated chemicals (PFCs) are emerging pollutants that have been used for half a century in a wide variety of industrial processes and consumer-based products. PFCs ha­ve received a lot of attention in the last ten years due to their detection in environmental and biological matrices as well as concerns regarding their persistence and toxicity. Recent studies indicate that municipal wastewater treatment plants are point sources of PFCs. The significance of PFCs discharges from wastewater treatment plants in Arizona was investi­gated in this research. A quantitative method consisting of acid wash-solvent extraction of the PFCs followed by solid phase extraction (SPE) clean-up and concentration was successfully developed to assess the presence of PFCs in environmental solid matrices. LC-MS/MS was employed to detect and quantify PFCs in sludge samples. Selected ion monitoring (SIM) analysis was used to improve detection limits for the perfluorinated compounds. The detection limits of the PFCs evaluated in this study were 50 pg L-1 for perfluorooctane sulfonate (PFOS), perfluorodecano sulfonate (PFDS) and perfluorodecanoic acid (PFDA), and 200 pg L-1 for perfluorohexane sulfonate (PFHXs) and perfluorooctanoic acid (PFOA). PFOS (77 ± 5 ng g-1 sludge dry weight) was the only perfluorinated compound detected in municipal sewage sludge samples from Tucson, Arizona.Los compuestos perfluorinados (Perfluorinated Chemicals, PFCs) son contaminantes emer­gentes que han sido utilizados por más de 50 años en una variedad de procesos industriales y en la producción de artículos de consumo humano. Los PFCs han recibido mucha aten­ción en los últimos diez años debido a su presencia en matrices bióticas y ambientales; así como también, a reportes relacionados con su persistencia y toxicidad. Las Plantas de Tra­tamiento de Aguas Residuales (PTARs) municipales han sido identificadas como fuentes puntuales de PFCs según estudios recientes. En este estudio se investigó la presencia de PFCs en las descargas de plantas de tratamiento de aguas residuales en Arizona. Un método cuantitativo basado en limpieza con ácido-extracción con solvente seguido de una limpieza-extracción en fase sólida (Solid Phase Extraction, SPE) fue exitosamente desarrollado para determinar la presencia de PFCs en matrices ambientales sólidas. Cro­matografía líquida de alta eficacia acoplada a espectrometría de masas en tándem (Liquid Chromatography copuled to Tandem Mass Spectrometry, LC-MS/MS) fue utilizada para detectar y cuantificar PFCs en lodos provenientes de las PTARs. Análisis por monitoreo de iones seleccionados (Selected Ion Monitoring, SIM) se empleó para mejorar los lími­tes de detección de los compuestos perfluorinados. Los límites de detección de los PFCs evaluados en este estudio fueron de 50 pg L-1 para sulfonato de perfluorooctano (Per­fluorooctane sulfonate, PFOS), sulfonato de perfluorodecano (Perfluorodecane sulfonate, PFDS) y ácido perfluorodecanoico (Perfluorodecanoic acid, PFDA), y 200 pg L-1 de sul­fonato de perfluorohexano (Perfluorohexane sulfonate, PFHXs) y ácido perfluorooctanoico (Perfluorooctanoic acid, PFOA). PFOS (77 ± 5 ng g-1 lodo peso seco) fue el único com­puesto perfluorinado detectado en los lodos provenientes de plantas de tratamiento de aguas residuales en Tucson, Arizona

Gene expression BackCLIP: a tool to identify common background presence in PAR-CLIP datasets

Abstract Motivation: PAR-CLIP, a CLIP-seq protocol, derives a transcriptome wide set of binding sites for RNA-binding proteins. Even though the protocol uses stringent washing to remove experimental noise, some of it remains. A recent study measured three sets of non-specific RNA backgrounds which are present in several PAR-CLIP datasets. However, a tool to identify the presence of common background in PAR-CLIP datasets is not yet available. Results: We used the measured sets of non-specific RNA backgrounds to build a common background set. Each element from the common background set has a score that reflects its presence in several PAR-CLIP datasets. We present a tool that uses this score to identify the amount of common backgrounds present in a PAR-CLIP dataset, and we provide the user the option to use or remove it. We used the proposed strategy in 30 PAR-CLIP datasets from nine proteins. It is possible to identify the presence of common backgrounds in a dataset and identify differences in datasets for the same protein. This method is the first step in the process of completely removing such backgrounds. Availability: The tool was implemented in python. The common background set and the supplementary data are available at https://github.com/phrh/BackCLIP. Contact

A review on the development of visible light-responsive WO3-based photocatalysts for environmental applications

The use of semiconductor photocatalysis is a promising, green, and sustainable technology to address solar energy conversion and environmental remediation issues. Among photocatalytically active semiconductors, considerable attention has been given to the visible-light active tungsten oxide (WO3, Eg value ≈ 2.7–3.1 eV). This semiconductor has several advantages: strong absorption in the visible spectrum range, stability in acidic and oxidative conditions, low cost, and low toxicity. However, WO3 presents fast recombination of charge carriers’ and exhibits low photocatalytic activity for reduction reactions due to its conduction band potential (+0.5 V versus NHE). Many strategies have been applied to enhance photocatalytic activity and solar energy utilization of WO3 by modifying the energy band position and reducing the charge carrier recombination. In this review, several approaches, such as designing with exposed facets and specific morphologies, doping with transition metals and non-metals, deposition of noble metals, and heterojunction construction, are summarized. Moreover, the photocatalytic properties of the reviewed WO3-based photocatalysts are discussed based on their environmental applications such as degradation of organic pollutants, air purification, CO2 photoreduction, hydrogen production from water splitting and recently, simultaneous wastewater treatment and electric energy generation by photocatalytic fuel cells. Finally, the summary, future perspectives, and challenges of design novel WO3-based photocatalysts with high efficiency are pointed out to meet the urgent demands of highly efficient technologies that use visible or solar energy for environmental applications

Arsenic remediation by formation of arsenic sulfide minerals in a continuous anaerobic bioreactor

Arsenic (As) is a highly toxic metalloid that has been identified at high concentrations in groundwater in certain locations around the world. Concurrent microbial reduction of arsenate (AsV) and sulfate (SO42-) can result in the formation of poorly soluble arsenic sulfide minerals (ASM). The objective of this research was to study As biomineralization in a minimal iron environment for the bioremediation of As-contaminated groundwater using simultaneous AsV and SO42- reduction. A continuous-flow anaerobic bioreactor was maintained at slightly acidic pH (6.25-6.50) and fed with AsV and SO42-, utilizing ethanol as an electron donor for over 250 d. A second bioreactor running under the same conditions but lacking SO42- was operated as a control to study the fate of As (without S). The reactor fed with SO42- removed an average 91.2% of the total soluble As at volumetric rates up to 2.9 mg As/(L∙h), while less than 5% removal was observed in the control bioreactor. Soluble S removal occurred with an S to As molar ratio of 1.2, suggesting the formation of a mixture of orpiment- (As2S3) and realgar-like (AsS) solid phases. Solid phase characterization using K-edge X-Ray absorption spectroscopy confirmed the formation of a mixture of As2S3 and AsS. These results indicate that a bioremediation process relying on the addition of a simple, low-cost electron donor offers potential to promote the removal of As from groundwater with naturally occurring or added sulfate by precipitation of ASM.12 month embargo; published online: 2 September 2015This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Panorama epidemiológico y clínico de la cardiopatía chagásica crónica en México

OBJECTIVE: To compare the epidemiological and clinical characteristics of chronic Chagas' heart disease to other dilated cardiomyopathies. METHODS: A study comprising 128 patients from a heart disease center was carried out from 1993 to 2003. Of them, 51 (40%) were Trypasonoma cruzi positive. Epidemiological data was obtained through interviews and clinical and serological data from health services. Statistic analysis was conducted using the Chi-square, Fischer, Mann-Whitney or Students' t-test as well as multivariate analysis. RESULTS: Chronic Chagas' disease patients were older (55±10 years old) than those patients with cardiopathy (42±17 years old). Most of them were born in rural areas (90% vs 68%), lived in poor (75% vs 16%), crowded households (45% vs 20%), together with domestic animals (71% vs 61%) and were aware of the Chagas' vector (73% vs 25%). Rhythm and conduction ECG abnormalities as well as permanent pacemaker were common among Chagas' patients (84% vs 55%, 78% vs 64% and 24% vs 10%, respectively). Congestive heart failure was more frequent among cardiomiopathy patients (88% vs 71%). Both groups had abnormal myocardial perfusion with normal epicardial arteries. Comorbidities were more frequent in cardiomiopathy patients than in chronic Chagas' disease patient (two cases only). CONCLUSIONS: Chagas' disease is the most common cause of dilated cardiomiopathy in the study hospital. Due to its regional distribution in Mexico, it deserves special attention and control programs proven to be effective in other countries.OBJECTIVO: Comparar las características epidemiológicas y clínicas de la cardiopatía chagásica crónica con otras miocardiopatías dilatadas. MÉTODOS: Se incluyeron a 128 pacientes consecutivos en un hospital de espcialidad, de 1993 a 2003 con miocardiopatías dilatadas, donde 51 (40%) con anti Tripanosoma cruzi. Se recopiló información epidemiológica por entrevista directa, y datos clínicos en los servicios asistenciales. Se utilizaron la prueba de la Chi-cuadrado o prueba exacta de Fischer, prueba t de Student ó la prueba de U de Mann Whitney y análisis multivariado. RESULTADOS: Los pacientes con cardiopatía chagásica crónica, eran más viejos (55±10 años) que los pacientes con miocardiopatías (42±17 años), nacieron en zonas rurales (90% vs 68%), en viviendas precarias (75% vs 16%), con hacinamiento (45% vs 20%), convivencia con animales domésticos (71% vs 61%) y conocían al vector (73% vs 25%). Los trastornos del ritmo y de la conducción, así como la colocación de marcapaso definitivo fueron frecuentes en los pacientes con cardiopatía chagásica crónica (84% vs 55%, 78% vs 64% Y 24% vs 10% respectivamente). La insuficiencia cardiaca congestiva venosa fue más frecuente en los pacientes con miocardiopatía seronegativa (88% vs 71%) y la perfusión miocárdic anormal con arterias epicárdicas normales fue igual en ambos grupos. Con respecto a co-morbilidad, los pacientes con cardiopatía chagásica crónica tenían sólo dos padecimientos, mientras que en el otro grupo era más amplia. CONCLUSIÓNES: La enfermedad de Chagas causa la miocardiopatía dilatada específica más común. Debido a su distribución regional en la República Mexicana, merece atención y se recomienda a nivel público adoptar medidas de prevención que ya probaron eficacia en otros países