747 research outputs found
Nefroblastoma espinal en un Rottweiler
El nefroblastoma espinal es una neoplasia infrecuente en el perro. Se diagnostica en animales jóvenes, afectando, casi exclusivamente, al segmento medular T10 -L2. En este trabajo, e describen los signos clínicos, resultados de las pruebas complementarias y los hallazgos histopatológicos de un perro con un nefroblastoma espinal.
Pseudotumor simulando lesiones malignas en lactantes
Se presentan dos casos clínicos, en dos lactantes, de tumoración de partes blandas de crecimiento rápido y aparición espontánea. Fue necesario emplear técnicas invasivas, dadas las dificultades en el diagnóstico diferencial con tumor de estirpe maligna, para llegar al tranquilizador diagnóstico de hematoma en evolución. Se discute la utilidad de la RM en el estudio de este tipo de lesiones.Two cases of soft tissue tumoration with fast
growth and spontaneus apparition in suckling infants are reported. Develop invasive methods to achieve the easeful final
diagnosis of evolutive haematoma was necessary because of
differential diagnosis with soft tissue sarcoma. There is a discusion on the use of MR in the study of this kind of lesion
Effect of acid treatment on the structure of sepiolite.
An ab initio determination of the structure of sepiolite after acid treatment (HCl 0.5 N for 24 h) was carried out using X-ray powder diffraction data. After acid treatment, the sections normal to the a and c axes presented discontinuities, ~2.25 Å wide, parallel to the (010) plane, with no electronic density maxima, thus suggesting that adjacent planes are joined by van der Waals-like residual links. Partial dissolution was detected on both octahedral and tetrahedral sheets, beginning by breaking the ribbons not along the edges, but in the centre, thus creating a 5.20x6.79 Å tunnel along the a axis. By interrupting the tetrahedral sheet, this mechanism changes the phyllosilicate-like nature of the sepiolite to an inosilicate-like structure.Peer reviewe
Antiangiogenic Therapy in Epithelial Ovarian Cancer
Approximately 75% of women with ovarian cancer are diagnosed at advanced stages (FIGO stage III/IV), with 15-23 months median global survival and 20% 5-year survival. Angiogenesis plays an important role in tumour development and proliferation. Increased angiogenesis is associated with worse clinical outcome in ovarian cancer. Here we review the play of bevacizumab in the treatment of ovarian cancer and also other antiangiogenic drugs. In total, to date there are no promising results for most of the reviewed antiangiogenic agents, except those already known for bevacizumab, trebananib, pazopanib, cediranib and nintedanib. Ongoing research will shed more light on this fascinating tumour process and its control
Is spillover relevant for hydrogen adsorption and storage in porous carbons doped with palladium nanoparticles?
Producción CientíficaExperiments have shown that the efficiency of nanoporous carbons to store hydrogen becomes enhanced by doping the material with metallic nanoparticles. In particular, doping with palladium has been used with success. The hypothesis to justify the enhancement has been that the Pd nanoparticles dissociate the hydrogen molecules and then the hydrogen atoms spill over the carbon substrate, where the hydrogen is retained. To test this hypothesis we have performed ab initio molecular dynamics simulations of the deposition of molecular hydrogen on Pd nanoparticles (Pd6 and Pd13) supported on graphene, which is a good model for the wall of a carbon nanopore. Three channels have been identified in the simulations: bouncing off the molecule, molecular adsorption, and dissociation of the molecule in two H atoms. The relative percentage of those channels is sensitive to the size of the Pd particle. Dissociation occurs more frequently on Pd13 and it generally takes place on the lateral regions of the Pd particles. However, in our simulations, we have not found a single case of H atoms or H2 molecules spilling over the carbon substrate. We have also tested the situation when several H atoms are preadsorbed on the Pd6 and Pd13 particles and found that not a single dissociation event occurs on these H-saturated nanoparticles. These results lead us to cast strong doubts on the validity of the spillover mechanism for explaining the enhancement of hydrogen adsorption on porous carbons doped with transition metal nanoparticles.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA050U14
¿Es adecuado el sistema español de evaluación de la actividad investigadora para su aplicación a las Ciencias de la Tierra y otros campos afines?
Through the survey «Research activities in the R&D system in Earth Sciences in Spain (1990-1994)>>, information about different aspects of the professional activity of Spanish researchers in this field has been retrieved, as well as their opinion about prevailing research evaluation criteria. Starting from survey's results, we discuss the suitability of the present Spanish scientific evaluation system for assessing research activity of said researchers. Results show scientist's disagreement with the prevailing evaluation procedures and criteria. More than 70 % of both University and CSIC researchers consider that evaluation criteria are inappropriate or unacceptable, being this percentage significantly higher than the obtained from scientists belonging to other institutions. Disagreement with evaluation criteria is significantly lower among authors that only publish in foreign journals. Positive correlation has been found between opinion about evaluation criteria and the level of consolidation and stability of research teams. Main cause of disagreement is concerned with the over-valuation of papers published in SCI journals and the scarce consideration given to high quality papers published in serious domestic journals and to other scientific contributions. Results suggest that the evaluation system could have been detrimental to researchers working in some scientific fields, but does not seem to have discriminate among basic and applied research or among research of local or national interest and those more internationally-oriented. The research evaluation system should consider the idiosyncrasy of the different scientific fields, as well as their particular and distinctive characteristics and dynamics. It should take into the adequate consideration quality scientific work that, despite being of particular importance in fields as Earth Sciences, is not published in SCI joumals.A través de la opinión expresada por los propios investigadores, se discute la idoneidad del actual sistema español de evaluación de la actividad investigadora, para su aplicación en el campo de las Ciencias de la Tierra. Dicha opinión ha sido obtenida a través de la encuesta «Actividades de investigación realizadas en el Sistema de I+D en Ciencias de la Tierra en España, 1990-1994», que recoge información sobre distintos aspectos de la actividad profesional de los investigadores españoles en este campo. Los resultados muestran su desacuerdo con los criterios y el procedimiento de evaluación actualmente vigentes. Más del 70 % tanto de los profesores universitarios como de los investigadores del CSIC considera que los criterios de evaluación son inadecuados o inaceptables, siendo su grado de disconformidad con los mismos significativamente más elevado que el de los investigadores del resto de instituciones. Este porcentaje es significativamente menor entre los científicos que publican exclusivamente en revistas extranjeras. Asimismo, se ha detectado una correlación positiva entre la opinión acerca de los criterios de evaluación y el nivel de consolidación y estabilidad de los equipos de investigación, de modo que cuanto mayor es éste más elevada es la proporción de juicios favorables a los mismos. El principal motivo de disconformidad con el procedimiento de evaluación se refiere a la excesiva importancia que se concede a los trabajos publicados en revistas del SCI, en detrimento de los publicados en revistas españolas de calidad y de otras contribuciones científicas. Los resultados indican que el sistema de evaluación podría estar produciendo una discriminación entre los investigadores pertenecientes a distintos campos científicos, más que entre investigación básica y aplicada o entre investigación de interés local y/o nacional y aquella de ámbito internacional. Consideramos que el sistema de evaluación debe tener en cuenta la idiosincrasia y características propias y distintivas de cada campo científico y debe tomar en la adecuada consideración los trabajos de contrastada calidad que, por diversos motivos, no se publican en revistas del SCI, los cuales tienen una especial importancia en ciertos campos científicos, entre los que se encuentran las Ciencias de la Tierra
Clinical and Molecular Study of the NOG Gene in Families with Mandibular Micrognathism
Q1Pacientes con Micrognatismo mandibularObjectives: Previous studies showed that noggin gene (NOG) sequence alterations, as well as epigenetic factors, could influence mandibular development. The aim of this study was to analyze clinical characteristics, NOG gene sequences, and promoter methylation sites in patients with mandibular micrognathism.
Materials and Methods: A total of 35 individuals of five Colombian families were subject to clinical and cephalometric analysis for mandibular micrognathism. One nonaffected individual of each family was included as a control. DNA was isolated from whole blood sample from all individuals by salting out method. Nine NOG gene fragments were amplified by polymerase chain reaction (PCR) and sequenced. Identification of CpG islands for methylation analysis at the NOG gene promoter was performed by MSP-PCR kit (Qiagen R).
Statistical Analysis: A descriptive statistical analysis was carried out evaluating the presence or absence of genetics variants and the methylation sites in the NOG gene.
Results: NOG sequence results of affected individuals with mandibular micrognathism for one of the families studied demonstrated that they were heterozygous for 672 C/A (new mutation). For a second family, individuals were heterozygous for 567 G/C (single nucleotide polymorphism [SNP] RS116716909). For DNA analyzed from all patients studied, no methylations were observed at the NOG gene promoter region.
Conclusion: Our results suggested that 672 C/A and 567 G/C variants could be involved in the presence of mandibular micrognathism. Moreover, lack of methylation sites at the NOG gene promoter region of all individuals studied suggests possibly other epigenetic factors could modulate mandibular growth. The search of genetic variants related with mandibular micrognathism will allow to predict in an integral way the development patterns of the patients and therefore establish a better clinical treatment.https://orcid.org/0000-0002-2112-2563https://orcid.org/0000-0002-9879-9775https://orcid.org/0000-0003-0770-9138https://orcid.org/0000-0003-2527-3593Revista Internacional - IndexadaA2N
Paleomagnetism from Deception Island (South Shetlands archipelago, Antarctica), new insights into the interpretation of the volcanic evolution using a geomagnetic model
Deception Island shows the most recent exposed active volcanism in the northern boundary of the Bransfield Trough. The succession of the volcanic sequence in the island is broadly divided into pre- and post-caldera collapse units although a well-constrained chronological identification of the well-defined successive volcanic episodes is still needed. A new paleomagnetic investigation was carried out on 157 samples grouped in 20 sites from the volcanic deposits of Deception Island (South Shetlands archipelago, Antarctic Peninsula region) distributed in: (1) volcanic breccia (3 sites) and lavas (2 sites) prior to the caldera collapse; (2) lavas emplaced after the caldera collapse (10 sites); and (3) dikes cutting pre- and the lower- most post-caldera collapse units (5 sites). The information revealed by paleomagnetism provides new data about the evolution of the multi-episodic volcanic edifice of this Quaternary volcano, suggesting that the present-day position of the volcanic materials is close to their original emplace- ment position. The new data have been combined with previous paleomagnetic results in order to tentatively propose an age when comparing the paleomagnetic data with a global geomagnetic model. Despite the uncertainties in the use of averaged paleomagnetic data per volcanic units, the new data in combination with tephra occurrences noted elsewhere in the region suggest that the pre-caldera units (F1 and F2) erupted before 12,000 year BC, the caldera collapse took place at about 8300 year BC, and post-cal- dera units S1 and S2 are younger than 2000 year BC
Upwelling and outwelling effects on the benthic regime of the continental shelf off Galicia, NW Spain
The benthic regime off the Galician coast of NW Spain was surveyed to assess biogenic enrichment from coastal upwelling and detritus outwelling from the rías, large coastal embayments: the Rías Altas along the northern and the Rías Bajas along the western coast, which have intense mussel aquaculture. Sediment samples were collected from 1984 to 1986 and used for geological, microbiological, and macrofaunal studies. Sub-bottom acoustic profiler records and grab and core samples identified two main mud deposits on the western shelf that were aligned north to south and parallel with the coastline. The major axis of the mud deposit, which extended south to the Portuguese border, is associated with the three most southern rías (Arosa, Pontevedra and Vigo) along the western shelf. Sediment particle size analysis showed that sediments on the western shelf were heterogeneous, and grain size increased from the inner shelf to the shelf break. On the northern shelf, sediments exhibited a more homogeneous textural distribution. Sediment organic matter followed a similar pattern with that of particle size. The highest organic matter values, 10%, occurred on the western shelf nearest the Rías Bajas, but these values decreased offshore to between 2 and 4%. On the northern shelf organic matter content was generally less than 4% but with patches of higher organic content. The composition and structure of macroinfauna on the northern shelf, where seasonal coastal upwelling results in benthic enrichment, showed mainly small, surface feeding, and fast growing polychaetes. In contrast, macroinfauna on the western shelf showed more subsurface, deposit-feeding polychaetes. A main difference between the two shelves is that off the rías Bajas, besides coastal upwelling, outwelling from the highly productive rías Bajas, with their intense mussel aquaculture, also enriches the coastal sediment regime with a steady source of organic matter. Although seasonal and interannual variations occurred in the benthic bacteria, their general density distribution followed the pattern of organic matter content and particle grain size seasonally and interannually. The highest numbers of bacteria occurred in the upwelling region off the northern shelf and nearest the Rías Bajas on the western shelf. Both coastal upwelling and organic outwelling from the rías Bajas support benthic production alongthe western Galician shelf. The main commercialdemersal finfishalongthis coast is hake, Merluccius merluccius and blue-whiting, Micomesistius poutassou. The norwegian lobster, Nephrops norvegicus is also an important crop, and is more abundant off the rías Bajas in the finer and organic-richsediments where there are abundant prey resources of benthic infauna
Efecto del sexo y la inclusión de glicerol en el pienso sobre la distribución de ácidos grasos en el triglicérido en ganado porcino
Concentration of C16:0 was higher and C18:1 y C18:2 lower in boars than in gilts in the subcutaneous fat of hams. Dietary inclusion of glycerol decrease C18:2 and PUFA concentration, thus decreasing fat unsaturation. Saturated fatty acids are concentrated in the external position of the triglyceride (Sn-1,3), while PUFA and MUFA are located preferentially in the inner position (Sn-2). No interaction was observed between position and either sex or dietary treatment. The PUFA/SAT index was affected by position, sex and dietary treatment, However, rations in which MUFA were involved were not significant. The C18:0/C18:2 index showed an interaction dietary treatment*position, in which the ratio is increased by dietary glycerol only in the Sn-1,3 position.Los machos castrados tuvieron una concentración más alta de C16:0 y más baja de C18:1 y C18:2 en la grasa subcutánea del jamón. La inclusión de glicerol en el pienso durante la fase de acabado produce una menor concentración de C18:2, del total de PUFA y, en consecuencia, una menor insaturación de la grasa. Los ácidos grasos saturados se concentraron especialmente en las posiciones externas (Sn-1,3), mientras que los MUFA y PUFA lo hicieron preferentemente en la posición central (Sn-2). No se observaron interacciones de la posición de los ácidos grasos individuales debidas al sexo o a la alimentación. La relación PUFA/SAT resultó significativa respecto a la posición, el sexo y la alimentación. Sin embargo, los índices en los que participan los MUFA son mucho más constantes e independientes del sexo y la alimentación. El cociente C18:0/C18:2 muestra una interacción glicerol*posición, de modo que dicho cociente aumenta específicamente en la posición 1,3 cuando los cerdos reciben glicerol, pero no se afecta (o lo hace con muy poca intensidad) en la posición 2
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