750 research outputs found
Tumores presacros. Reporte de serie de casos
Introducción: Los tumores presacros son un raro y diverso grupo de lesiones que se originan en el espacio presacro, infrecuente y de difícil diagnóstico. El objetivo de este trabajo es describir una serie de casos con respecto a las características clínicas, diagnóstico y manejo. Metodología: Recolección de pacientes quienes fueron diagnosticados con tumores presacros desde el año 1988 a 2013. Revisamos la clínica, tiempo de evolución, métodos diagnósticos, el abordaje quirúrgico, patología y complicaciones. Resultados: Nueve pacientes fueron incluidos en este trabajo. 7 de los 9 pacientes presentaron como síntoma principal el dolor. El tiempo de evolución medio fue de 9.8 meses. Diagnóstico fue realizado con tacto rectal en todos los pacientes y confirmado con tomografía axial pélvica 9 pacientes y resonancia magnética nuclear pélvica en 5 pacientes. La patología: teratoma quístico maduro (n = 3), cordoma (no: 1), quiste epidermoide (no=1), fibrohistiocitoma de bajo grado (no =1), fibromatosis (no =1), angiomixoma agresivo (no =1). El abordaje quirúrgico principal fue la vía posterior de (kraske) en 6 pacientes y en 2 por laparotomía. 1 paciente no se llevó a cirugía. La resección completa se obtuvo en un 87%. No se presentó complicaciones tempranas postoperatorias. Complicaciones tardías en 1 caso (12%) por obstrucción intestinal. Se presentó 1 caso de recurrencia por resección parcial tumoral. Conclusión: Los tumores presacros son una patología infrecuente a nivel mundial, siendo un reto para el cirujano su diagnóstico y manejo.Background: Presacral tumors are a rare and diverse group of lesions that originate in the presacral space. Given its rarity, it is difficult to reach an early diagnosis of tumors presenting as difficult to manage. The aim of this paper is to describe a series of cases with respect to clinical features, diagnosis and management. Methodology: Collection of patients who were diagnosed with presacral tumors since 1988-2013. We reviewed the clinical, evolution, diagnosis, surgical approach, pathology and complications. Results: Nine patients were included in this study. 7 of the 9 patients had primary symptom is pain. The average evolution time was 9.8 months. Diagnosis was made with digital rectal examination in all patients and confirmed in 9 patients pelvic CT and pelvic MRI in 5 patients. Pathology: mature cystic teratoma (n = 3), chordoma (no: 1), epidermoid cyst (no = 1), low-grade fibrous histiocytoma (no = 1), fibromatosis ( no = 1), aggressive angiomyxoma (no = 1). The main surgical approach was the posterior (Kraske) in 6 patients and in 2 by laparotomy. 1 patient had no surgery took. Complete resection was obtained in 87%. No early postoperative complications present. Late complications in 1 patient (12 %) for intestinal obstruction. Was only 1 case of partial resection tumor recurrence. Conclusion: Presacral tumors are an uncommon worldwide, being difficult to diagnosis and management.Hospital Militar Central, Universidad Del Rosari
Multiple-fault detection methodology based on vibration and current analysis applied to bearings in induction motors and gearboxes on the kinematic chain
© 2016 Juan Jose Saucedo-Dorantes et al. Gearboxes and induction motors are important components in industrial applications and their monitoring condition is critical in the industrial sector so as to reduce costs and maintenance downtimes. There are several techniques associated with the fault diagnosis in rotating machinery; however, vibration and stator currents analysis are commonly used due to their proven reliability. Indeed, vibration and current analysis provide fault condition information by means of the fault-related spectral component identification. This work presents a methodology based on vibration and current analysis for the diagnosis of wear in a gearbox and the detection of bearing defect in an induction motor both linked to the same kinematic chain; besides, the location of the fault-related components for analysis is supported by the corresponding theoretical models. The theoretical models are based on calculation of characteristic gearbox and bearings fault frequencies, in order to locate the spectral components of the faults. In this work, the influence of vibrations over the system is observed by performing motor current signal analysis to detect the presence of faults. The obtained results show the feasibility of detecting multiple faults in a kinematic chain, making the proposed methodology suitable to be used in the application of industrial machinery diagnosis.Postprint (published version
Distribución espacial de los anélidos poliquetos de fondos blandos en la ensenada de baiona (Ría de Vigo, Galicia, Noroeste de España)
The spatial distribution of the polychaete fauna in the subtidal soft-bottoms of the Ensenada de Baiona (Galicia, NW Spain) was studied by means of quantitative sampling and multivariate analyses. Several faunistic assemblages were determined, which were closely related to the sediment distribution pattern in the inlet. The coarse-medium sand fauna was mainly dominated by syllids and pisionids. Finer sediments (fine sand to mud) showed a greater abundance of deposit-feeding species, mostly spionids, cirratulids and capitellids. The greatest number of species and diversity were found in mixed sediments with medium and fine sand. Organically enriched muds around Baiona harbour have an impoverished fauna, with a high dominance of Cossura pygodactylata Jones, 1956.La distribución espacial de la fauna de poliquetos de fondos blandos submareales de la ensenada de Baiona (Galicia, NW España) ha sido estudiada mediante técnicas de muestreo cuantitativo. Los análisis multivariantes diferenciaron varias asociaciones faunísticas, que coinciden en gran medida con los patrones de distribución sedimentaria en el área estudiada. La fauna de arenas gruesas y medias está dominada principalmente por sílidos y pisiónidos, mientras que los sedimentos más finos (arenas finas a fangos) muestran una mayor abundancia de organismos depositívoros como espiónidos, cirratúlidos y capitélidos. Se han observado los mayores valores de riqueza específica y diversidad en sedimentos mixtos de arena fina y media. Los fangos orgánicamente enriquecidos del puerto de Baiona muestran una fauna empobrecida con una gran dominancia de Cossura pygodactylata.  
Effectiveness of Chemical and Thermal Treatments on Control Rhizopus stolonifer Fruit Infection Comparing Tomato Cultivars with Different Sensitivities to Cracking
Tomatoes are among the most important horticultural crops; however, it is estimated that 30% of tomato yield is lost due to postharvest rot due to Rhizopus stolonifer, a fungus which requires lesions to initiate the infectious process. Tomato fruit cracking is a physiopathy which causes significant economic losses, since cracking is the door used by the fungus. In this experiment, 14 cultivars of tomato of different types were used. Fruit sampling was carried out in the middle of the crop cycle, coinciding with the peak of yield; then, the fruits were divided into two groups: one group was inoculated with Rhizopus in order to assess the effectiveness of washing, whilst the other was treated with sterile water. The fruits of each group were divided into lots to be treated with six washing treatments: dipping in hot water at 20, 40 and 60 °C for 20 s; the fruits were then sprayed with the following solutions: 0.6% of Hydrogen Peroxide 23% + Peracetic acid 15%; commercial bleach at 0.5% and 2% of Hydrogen Peroxide 50%. The control sample was not washed. The results show that there was an influence of cultivar on fruit cracking, which was strongly related with Rhizopus infection. Three cultivars were not susceptible to cracking, and therefore, were not sensitive to Rhizopus infection. The effectiveness of different washing treatments of tomato fruits depends on several factors; nonetheless, hot water treatment has been shown to be more effective than the use of chemical products such as commercial bleach or hydrogen peroxide. Another factor, the susceptibility of cultivars to cracking, determines the effectiveness of the washing treatment. The results provide an important basis for making decisions about the washing management of tomato fruits in packaging houses
Patrones de distribución de la familia Syllidae (Annelida: Polychaeta) en praderas de las fanerógamas marinas Zostera marina y Zostera noltei en la ensenada de O Grove (Galicia, NO España)
This paper describes the distribution and composition of the syllid fauna inhabiting seagrass meadows in the Ensenada de O Grove (NW Spain). Samples were collected on muddy sediments colonized by either Zostera marina L., Zostera noltei Hornemann or by a mixed meadow with both species. Syllids were dominant (13340 individuals; 37% of total polychaete abundance), including 22 species (12 genera). The mixed meadows housed the highest number of species and the Z. noltei meadow had practically no syllids. The dominant species were Exogone naidina, Parapionosyllis elegans, Parexogone hebes and Prosphaerosyllis campoyi ( > 80% of total abundance). Carnivores (mainly species of Parapionosyllis, Amblyosyllis, and Streptosyllis) were dominant, especially in muddy sand with either Z. marina or Z. noltei and sandy mud with a mixed meadow. The most important abiotic variables for explaining the composition and distribution of the syllid fauna were bottom water salinity, sorting coefficient and carbonate content. The highest number of species was recorded at sites with a high salinity and carbonate content and the lowest at sites with a high sorting coefficient.El presente trabajo describe la distribución y composición de los sílidos encontrados en las praderas de fanerógamas de la Ensenada de O Grove (NO España). Los fondos fangosos estudiados están colonizados por Zostera marina L., Zostera noltei Hornemann o por ambas especies de fanerógamas. Los sílidos fueron la familia de poliquetos dominante numéricamente (13340 individuos, 37% total de la abundancia total de poliquetos) representados por 22 especies (12 géneros). Los fangos arenosos con pradera mixta albergaron el mayor número de especies de sílidos mientras que en los fondos de fango con Z. noltei estuvieron prácticamente ausentes. Las especies más abundantes fueron Exogone naidina, Parapionosyllis elegans, Parexogone hebes y Prosphaerosyllis campoyi ( > 80% abundancia total). Los carnívoros (principalmente especies de Parapionosyllis, Amblyosyllis y Streptosyllis) fueron dominantes especialmente en arenas fangosas con Z. marina o Z. noltei y en fangos arenosos con una pradera mixta. Las variables abióticas más importantes a la hora de explicar la composición y distribución de los sílidos fueron la salinidad del agua de fondo, el coeficiente de selección y el contenido en carbonatos; así, se ha encontrado un elevado número de especies en estaciones con salinidad y contenido en carbonatos más elevados, en comparación con estaciones con un mayor coeficiente de selección
Distribución de los poliquetos de fondos blandos en una ría gallega (NO España)
Macrobenthic polychaete distributions were studied along the soft-bottoms of the Ensenada de San Simón (Galicia, NW Spain). Results suggest that the distribution and abundance of polychaetes in the inlet were highly dependent on depth, sediment characteristics (grain size, organic matter and calcium carbonate content) and bottom water temperature. In the inner area of the inlet, intertidal bottoms colonised by the seagrasses Zostera marina and Z. noltii were dominated by spionids and capitellids, and showed low species number and diversity. Shallow muddy bottoms of central areas were mostly dominated by ampharetids, terebellids and cirratullids. These families along with paraonids, maldanids and syllids were the most abundant families in the deeper subtidal muddy bottoms at the mouth of the inlet. These sediments also showed the highest number of species, diversity and density of individuals.La distribución de los poliquetos macrobentónicos ha sido estudiada en los fondos blandos de la Ensenada de San Simón (Galicia, NO España). La profundidad, las características del sedimento (granulometría, contenido en materia orgánica y carbonatos) y la temperatura del agua del fondo fueron los principales factores que determinaron la distribución y abundancia de los poliquetos en la ensenada. En la zona más interna, los fondos intermareales colonizados por las fanerógamas Zostera marina y Z. noltii estuvieron dominados numéricamente por espiónidos y capitélidos, y mostraron bajos valores de diversidad y número de especies. Los fondos fangosos someros del área central presentaron una fauna de poliquetos dominada principalmente por anfarétidos, terebélidos y cirratúlidos. Asimismo, estas familias estuvieron presentes en los fondos más profundos de la boca de la ensenada, donde paraónidos, maldánidos y sílidos mostraron una dominancia numérica importante. Los máximos valores de diversidad, número de especies y densidad de individuos se registraron en estos fondos submareales fangosos
Distribución espacial de la macrofauna bentónica de sedimentos submareales de la Ría de Aldán (Galicia, Noroeste de España)
In the summer of 1997, 27 subtidal stations were quantitatively sampled in the Ría de Aldán. A total of 81770 individuals were collected, comprising 496 species. The distribution and composition of benthic assemblages was correlated to the sedimentary characteristics which, in turn, depend on the hydrodynamic features; those patterns are reflected in a sedimentary gradient present along the ria, which is characterized by an increasing grain size from the inner margins towards the mouth. Several faunal assemblages were determined through multivariate analyses and their composition is compared with that of several communities or facies previously described from similar sediments. The Venus fasciata community was present in clean coarse sediments of the outer ria, the Venus gallina and Tellina fabula-Tellina tenuis communities in the fine-sand bottoms at the centre and margins of the ria, a transition assemblage between the Venus fasciata and the Venus gallina communities in the medium-sand sediments, and a mix of species from the Syndosmya alba and the Amphiura communities in shallower and muddy sediments in the inner areas. In general, subtidal sediments of the Ría de Aldán showed a high benthic diversity which is related to the great sedimentary heterogeneity and the lack of significant anthropogenic alterations.Durante el verano de 1997, se hicieron muestreos en 27 estaciones submareales de modo cuantitativo en la Ría de Aldán. Se recolectaron un total de 81770 individuos, pertenecientes a 496 especies. Los análisis multivariantes permitieron distinguir varias asociaciones faunísticas cuya composición puede ser referida a comunidades o facies previamente descritas de sedimentos similares: la comunidad de “Venus fasciata” está presente en sedimentos limpios de granulometría gruesa de la parte externa de la ría, las comunidades de “Venus gallina” y “Tellina fabula-Tellina tenuis” aparecen principalmente en arena fina en las áreas marginal y central, una fauna de transición entre las comunidades de V. fasciata y V. gallina se encuentra en fondos de arena media, y los fondos someros fangosos de la zona interna están caracterizados por una mezcla de especies propias de las comunidades de “Syndosmya alba” y “Amphiura”. En general, los sedimentos submareales de la Ría de Aldán presentaron una alta diversidad bentónica relacionada con la gran heterogeneidad sedimentaria y la ausencia de perturbaciones humanas significativas
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