2,104 research outputs found

    Dimensionalities of Weak Solutions in Hydrogenic Systems

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    A close inspection on the 3D hydrogen atom Hamiltonian revealed formal eigenvectors often discarded in the literature. Although not in its domain, such eigenvectors belong to the Hilbert space, and so their time evolution is well defined. They are then related to the 1D and 2D hydrogen atoms and it is numerically found that they have continuous components, so that ionization can take place

    Radical distal ureterectomy secondary to an urotelial cancer and ureteral reconstruction robot-assisted. Case report

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    Indexación: Web of Science; ScieloObjective: To report a case of distal ureterectomy with robotic-assisted laparoscopic reimplantation using a Boari flap technique. Material and Methods: We report a 55 year old man with a diagnosis of distal ureteral urothelial carcinoma without multifocality. Results: A radical distal ureterectomy and robotic-assisted laparoscopic vesicoureteral reimplantation using a Boari flap technique was performed with the da Vinci S-HD surgical system. The operative time was 210 minutes, the estimated blood loss was 200 mL. The hospital stay was 48 hours, without perioperative complications. The histopathological study showed a high grade non-muscle invasive urothelial carcinoma of the distal ureter (pT1NxMx) with negative margins. Conclusions: The distal radical ureterectomy with Boari replacement is feasible and more precise with robotic assistance. Its oncological role must be demostrated with a larger number of cases.Objetivo: Comunicar un caso de tumor ureteral distal tratado con ureterectomía radical y neoimplante vesicoureteral con técnica de Flap Boari asistida por robot. Material y Métodos: Paciente hombre de 55 años, con diagnóstico de carcinoma urotelial de uréter distal sin compromiso multifocal. Resultados: Se realizó ureterectomía distal radical y neoimplante vesicoureteral con Flap Boari asistido por Robot da Vinci S-HD. El tiempo operatorio fue de 210 minutos, con un sangrado estimado de 200 ml. La estadía hospitalaria fue de 48 horas, sin complicaciones perioperatorias. El estudio histológico mostró un carcinoma urotelial de alto grado con infiltración de la lámina propia (pT1NxMx) y márgenes quirúrgicos negativos. Conclusiones: La ureterectomía radical distal con reconstrucción tipo Boari es técnicamente factible y más precisa con la asistencia robótica. Su rol oncológico requiere de validación con mayor número de casos.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-40262011000400013&nrm=is

    Relationship between the isometric force of the dominant hand and the Body Mass Index of university students

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    INTRODUCTION: Strength is the neuromuscular capacity to overcome or counter resistances through muscular activity and is closely linked to all the motor actions that the human being develops, and to his body mass index. OBJECTIVE: To determine the level of correlation between body mass index (BMI) and the isometric strength of the dominant hand of university students. METHOD: The strength was evaluated with a TAKEI SCIENTIFIC INSTRUMENT 5401 dynamometer to 70 university students using a random sampling method using a descriptive transactional design. We obtained data that were processed with a bivariate correlation obtaining the Pearson coefficient. We used SPSS ver. 15. RESULTS: The studied age was 23 ± 1.9 years, with a length of 165.6 cm. ± 7.72 for women and 173.7 cm. ± 7.95 men, as well as a weight in women of 64.1 ± 14.82 kg and men 82.3 ± 14.72 kg, which results in a BMI for women of 25.01 ± 4.405 m2/kg and 25.06 with ± 4.398 m2/kg for men. On the other hand, the female isometry strength was 3.08. ± 0.613 Kg and for men was 3.68 ± 0.839 Kg. In females, there was not correlation between the BMI and isometric strength (Sig = .192). Contrary, in males, there was a significant and negative correlation grade between the BMI and isometric strength (r = -0,452; Sig. = 0.035). CONCLUSIONS: In this study, it was observed that as BMI increases, strength does not grow. Therefore, other variables should be evaluated to understand what is related to the overweight or obesity of students

    Automated detection of parenchymal changes of ischemic stroke in non-contrast computer tomography: a fuzzy approach

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    The detection of ischemic changes is a primary task in the interpretation of brain Computer Tomography (CT) of patients suffering from neurological disorders. Although CT can easily show these lesions, their interpretation may be difficult when the lesion is not easily recognizable. The gold standard for the detection of acute stroke is highly variable and depends on the experience of physicians. This research proposes a new method of automatic detection of parenchymal changes of ischemic stroke in Non-Contrast CT. The method identifies non-pathological cases (94 cases, 40 training, 54 test) based on the analysis of cerebral symmetry. Parenchymal changes in cases with abnormalities (20 cases) are detected by means of a contralateral analysis of brain regions. In order to facilitate the evaluation of abnormal regions, non-pathological tissues in Hounsfield Units were characterized using fuzzy logic techniques. Cases of non-pathological and stroke patients were used to discard/confirm abnormality with a sensitivity (TPR) of 91% and specificity (SPC) of 100%. Abnormal regions were evaluated and the presence of parenchymal changes was detected with a TPR of 96% and SPC of 100%. The presence of parenchymal changes of ischemic stroke was detected by the identification of tissues using fuzzy logic techniques. Because of abnormal regions are identified, the expert can prioritize the examination to a previously delimited region, decreasing the diagnostic time. The identification of tissues allows a better visualization of the region to be evaluated, helping to discard or confirm a stroke.Peer ReviewedPostprint (author's final draft

    Pleiotropic contribution of rbfox1 to psychiatric and neurodevelopmental phenotypes in two zebrafish models

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    RBFOX1 is a highly pleiotropic gene that contributes to several psychiatric and neurodevelopmental disorders. Both rare and common variants in RBFOX1 have been associated with several psychiatric conditions, but the mechanisms underlying the pleiotropic effects of RBFOX1 are not yet understood. Here we found that, in zebrafish, rbfox1 is expressed in spinal cord, mid- and hindbrain during developmental stages. In adults, expression is restricted to specific areas of the brain, including telencephalic and diencephalic regions with an important role in receiving and processing sensory information and in directing behaviour. To investigate the contribution of rbfox1 to behaviour, we used rbfox1sa15940, a zebrafish mutant line with TL background. We found that rbfox1sa15940 mutants present hyperactivity, thigmotaxis, decreased freezing behaviour and altered social behaviour. We repeated these behavioural tests in a second rbfox1 mutant line with a different genetic background (TU), rbfox1del19, and found that rbfox1 deficiency affects behaviour similarly in this line, although there were some differences. rbfox1del19 mutants present similar thigmotaxis, but stronger alterations in social behaviour and lower levels of hyperactivity than rbfox1sa15940 fish. Taken together, these results suggest that mutations in rbfox1 lead to multiple behavioural changes in zebrafish that might be modulated by environmental, epigenetic and genetic background effects, and that resemble phenotypic alterations present in Rbfox1-deficient mice and in patients with different psychiatric conditions. Our study, thus, highlights the evolutionary conservation of rbfox1 function in behaviour and paves the way to further investigate the mechanisms underlying rbfox1 pleiotropy on the onset of neurodevelopmental and psychiatric disorders

    Estructura y estabilidad térmica del poli (3-hidroxibutirato), PHB

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    Los biopolímeros obtenidos a partir de recursos naturales renovables se caracterizan por su carácter biodegradable e inocuidad siendo éstas las principales ventajas frente a materiales sintéticos de origen petroquímico. Actualmente, se producen gran variedad de biopolímeros destinados a diferentes campos de aplicación. Dentro de esta clase de materiales producidos y comercializados en el mundo se encuentran los poli-hidroxialcanoatos (PHA)s. Esta familia de biopolímeros comprende al poli(3-hidroxi-butirato) - PHB, el poli(3- hidroxivalerato) - PHV, entre otros. Una de las características más relevante de estos materiales es la posibilidad de que puedan ser procesados de igual forma que los polímeros sintéticos. El objetivo de este trabajo consiste en el estudio estructural y térmico de un poli(3-hidroxibutirato) comercial con el propósito de determinar las condiciones óptimas de procesamiento de este biopolímero. La morfología del PHB se estudió mediante Microscopía Electrónica de Barrido (SEM). La determinación de la estructura química se realizó a través de Espectroscopía Infrarroja con Transformada de Fourier (FTIR) y las propiedades térmicas y el grado de cristalinidad del biopolímero se estudiaron mediante Calorimetría Diferencial de Barrido (DSC). La estabilidad térmica se evaluó a través de un Análisis Termogravimétrico (TGA) para determinar los rangos de temperaturas de degradación. Las muestras se calentaron en atmósfera de oxígeno desde temperatura ambiente hasta 700 °C con una velocidad de calentamiento de 10 °C/min en una balanza termogravimétrica TA Instruments. Las micrografías SEM evidenciaron la presencia de gránulos de morfología poliédrica con un tamaño promedio de 1,5 mm. Además, se observó cierta rugosidad superficial que podría atribuirse al grado de cristalinidad del PHB. Mediante FTIR se detectaron las bandas características asociadas a los grupos funcionales presentes en el biopolímero. A partir del estudio calorimétrico, se determinó que la temperatura de fusión del PHB se encuentra alrededor de 183 ºC y el grado de cristalinidad del material estudiado fue de 56 %. Por otra parte, el análisis termogravimétrico reveló que la temperatura de degradación de este biopolímero es de 262 ºC. Los resultados obtenidos muestran que el procesamiento del PHB se encuentra acotado, a diferencia de los polímeros sintéticos, a un estrecho rango de temperaturas. A pesar de esta restricción operativa, este polímero resulta interesante dado su carácter biodegradable, origen renovable y propiedades mecánicas comparables a las de los materiales poliméricos derivados del petróleo como el polipropileno.Centro de Investigación y Desarrollo en Criotecnología de Alimento

    Transcriptomic and genetic studies identify NFAT5 as a candidate gene for cocaine dependence

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    Cocaine reward and reinforcing effects are mediated mainly by dopaminergic neurotransmission. In this study, we aimed at evaluating gene expression changes induced by acute cocaine exposure on SH-SY5Y-differentiated cells, which have been widely used as a dopaminergic neuronal model. Expression changes and a concomitant increase in neuronal activity were observed after a 5 μ cocaine exposure, whereas no changes in gene expression or in neuronal activity took place at 1 μ cocaine. Changes in gene expression were identified in a total of 756 genes, mainly related to regulation of transcription and gene expression, cell cycle, adhesion and cell projection, as well as mitogen-activeated protein kinase (MAPK), CREB, neurotrophin and neuregulin signaling pathways. Some genes displaying altered expression were subsequently targeted with predicted functional single-nucleotide polymorphisms (SNPs) in a case-control association study in a sample of 806 cocaine-dependent patients and 817 controls. This study highlighted associations between cocaine dependence and five SNPs predicted to alter microRNA binding at the 3'-untranslated region of the NFAT5 gene. The association of SNP rs1437134 with cocaine dependence survived the Bonferroni correction for multiple testing. A functional effect was confirmed for this variant by a luciferase reporter assay, with lower expression observed for the rs1437134G allele, which was more pronounced in the presence of hsa-miR-509. However, brain volumes in regions of relevance to addiction, as assessed with magnetic resonance imaging, did not correlate with NFAT5 variation. These results suggest that the NFAT5 gene, which is upregulated a few hours after cocaine exposure, may be involved in the genetic predisposition to cocaine dependence
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