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Sample records for resonancia magnetica cprm

  1. Imagenoligía para el siglo XXI resonancia magnetica

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    Mejía González, Mauricio; Fundación Valle de Lili

    1998-01-01

    ¿Qué es la resonancia magnetica?/¿Cómo funciona la resonancia magnética?/¿Para que se utiliza la resonancia magnética?/¿En que casos no se debe hacer resonancia magnética?/¿Se puede hacer resonancia a niños o mujeres embarazadas?/¿Qué se siente durante el examen?/¿Se requiere de medio de contraste?/¿Qué preparación previa se debe tener?/¿Que ventajas tiene la resonancia sobre otros métodos para imágenes diagnósticas?

  2. Brain MRI lesions in neuromyelitis optica: clinical case; Lesiones cerebrales de resonancia magnetica en neuromielitis optica: caso clinico

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    Rosales Bravo, Luis Guillermo; Heyden Cordero, Marvin; Chinchilla Weinstok, Dennis; Mendelewicz Goldwaig, Isaias, E-mail: neurologia.cima@gmail.com [Caja Costarricense del Seguro Social, Hospital Mexico, Div. de Neurologia, San Jose (Costa Rica)

    2011-10-15

    Many cases of patients with neuromyelitis optica have submitted without demyelinating lesions in the cerebral white matter, it has documented that this entity can cause from the onset of illness or through its natural evolution. Diagnostic methods currently as Magnetic Resonance Imaging (MRI) and specific antibodies in plasma (such as antiaquaporin-4) have been diagnosed of neuromyelitis optica cases that were initially confused with multiple sclerosis. Disease in Costa Rica has been little prevalent and is not exactly known what the prevalence and incidence. The degree of disorder is illustrated through a case study, both in the cerebral white matter as spinal cord, in a patient with neuromyelitis optica during a follow-up period of 4 years. This is the first case that has been reported in the scientific literature of Costa Rica. (author) [Spanish] Muchos casos de pacientes con neuromielitis optica se han presentado sin lesiones desmielinizantes en la sustancia blanca cerebral, se ha documentado que esta entidad puede causarlas desde el inicio de la enfermedad o a traves de su evolucion natural. Los metodos de diagnostico en la actualidad como la Imagen por Resonancia Magnetica (IRM) y la determinacion de anticuerpos especificos en plasma (como la antiaquaporina-4) han logrado diagnosticar algunos casos de neuromielitis optica que inicialmente fueron confundidos con esclerosis multiple. La enfermedad en Costa Rica ha sido poco prevalente y no se ha conocido con exactitud cual es la prevalencia e incidencia. El grado de afeccion ha sido ilustrado a traves de un caso clinico, tanto en la sustancia blanca cerebral como espinal, en un paciente con neuromielitis optica durante un periodo de seguimiento de 4 anos. Este es el primer caso que ha sido reportado en la literatura cientifica de Costa Rica. (autor)

  3. Comparison between magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP); Comparacion entre calongiografia por resonancia magnetica (CPRM) y colangiografia retrograda endoscopia (CPRE)

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    Pulpeiro, J. R.; Armesto, V. [Clinica Nosa Senora dos Ollos Grandes. Lugo (Spain); Lopez-Roses, L.; Lancho, A.; Gonzalez, A. [Hospital Xeral. Lugo (Spain)

    2000-07-01

    To assess the correlation between magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP). The authors carried out a prospective study of 71 patients suspected of having biliary diseases. MRCP was performed, followed by ERCP.MRCP was done with a 1.5-T system using hypergradients, abdominal phase array coil and single-shot fast spin-echo (SSFSE) sequences with maximum signal intensity in T2-weighted images. This sequence only provides images of the fluids, similar to those obtained with ERCP. The results of ERCP were employed as a reference standard. Thirty patients were found to have stenosis (19 malignant and 11 benign). 25 had choledocholithiasis and 16 showed no abnormal findings. The correlation was complete in patients with stenosis. MRCP detected 23 cases of choledocholithiasis (ERCP was normal in the remaining two patients, but calculi were discovered on shpincterotomy). MRCP confirmed the normal condition of the bile duct in 12 of the 16 patients free of biliary disease (2 patients in whom ERCP had been normal had been diagnosed as having bile duct dilatation due to choledocholithiasis 24 hours and 10 days earlier, respectively, and two cases of presented ectasia due to fibrosis of the sphincter of Oddi showed good emptying during ERCP). MRCP using SSFSE is highly correlated with ERCP, which should be reserved for cases in which the diagnosis is in doubt or endoscopic management is necessary. (Author) 25 refs.

  4. Recurrent back pain after diskectomy: MRI findings MR of the postoperative lumbar spine; Recurrencia del dolor lumbar en la columna operada: Hallazgos en Resonancia Magnetica

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    Aparicio, Rocio; Eguren, Leonor Z; Schinder, Humberto; Stur, Mariela [CIMA, Sanatorio Mapaci, Rosario, Santa Fe (Argentina)

    2008-07-01

    Purpose: To show the morphological changes in postoperative lumbar spine. Material and methods: We reviewed 128 Magnetic Resonance Imaging (MRI) studies of lumbar spine. All patients complained of low back pain and had a previous lumbar surgery (1 month to 8 years). All the examinations include axial and sagittal Gadopentate-dimeglumine enhanced T1 weighted imaging. Results: Only 7,8% have the normal appearance of the postoperative lumbar spine. Epidural scar was found in 69% of examinations; of this group, 72% showed radicular involvement, and 28% had no radicular involvement. Recurrent disc herniation was found in 14,8% of exams, using gadopentate-dimeglumine to assist the differentiation from epidural fibrosis; infections like spondylodiscitis and abscess in 12,5%. Other findings included arachnoiditis, pseudomeningoceles and seromas. Conclusions: MRI is a useful method to study the postoperative lumbar spine, specially when enhanced with gadopentate-dimeglumine. Enhanced images can differentiate two of the major complication like epidural fibrosis, and recurrent disc herniation. Spondylodiscitis are important and frequent too. Although the findings of complications in our series in the postoperative lumbar spine represent 92,18 %, these not always explain the symptomatology. Therefore, the interrelation is important with the surgeon to determine which abnormalities are clinically significant. (authors) [Spanish] Objetivo: Mostrar los hallazgos evidenciados en Resonancia Magnetica (RM) en pacientes operados de columna lumbar. Material y metodos: Se evaluaron retrospectivamente 128 estudios de RM de columna lumbar. Todos los pacientes consultaron por dolor lumbar y tenian antecedentes quirurgicos de un tiempo de evolucion que variaba entre 1 mes y 8 anos. En todos los casos el protocolo de estudio incluyo secuencias axiales y sagitales T1 con gadolinio, ademas del protocolo habitual. Resultados: Solo el 7,8 % de los estudios mostro los hallazgos postoperatorios

  5. Noninvasive study of anatomic variations of the bile and pancreatic duct using magnetic resonance cholangiopancreatography; Estudio no invasivo de variantes anatomicas de la via biliar y pancreatica mediante colangiopancreatografia por resonancia magnetica (CPRM)

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    Fernandez, E.; Falco, J.; Campo, R.; Martin, J.; Brullet, E. [SDI-UDIAT Corporacio Sanitaria Parc Tauli. Sabadell (Spain); Espinos, J. [Hospital Mutua de Tarrasa (Spain)

    1999-07-01

    To identify anatomic variations of the bile duct and pancreatic duct and papillary anomalies by means of magnetic resonance cholangiopancreatography (MRCP) and determine their correlation with endoscopic retrograde cholangiopancreatography (ERCP) findings. Eighty-five patients were selected by means of a prospective study comparing MRCP and ERCP. Coronal and axial HASTE images and coronal and oblique coronal RARE images were acquired in all the patients. Four of the studies (6%) were excluded because of poor technical quality. Anatomic variations were observed in 26 cases (30.5%), including trifurcation (n=7; 27%), right hepatic duct draining into left hepatic duct (n=2, 7.7%), right hepatic duct draining into common bile duct (n=4; 15.4%), extrahepatic confluence (n=2; 7.7%), medial cystic duct (n=2; 7.7%), parallel cystic duct (n=3; 11.5%), juxtapapillary duodenal diverticulum (n=3; 11.5%) and pancreas divisum (n=3; 11.5%). A good correlation was observed between the MRCP and ERCP findings. The introduction of MRCP into the noninvasive study of biliary disease may be useful in the detection of anatomic variations relevant to laparoscopic surgery and other endoscopic and interventional techniques. (Author) 11 refs.

  6. Nuclear magnetic resonance in the evaluation of the disk luxation in the temporomandibular articulation conditioned for degenerative osseous changes; Resonancia magnetica nuclear en la valoracion de la luxacion discal en la articulacion temporomandibular condicionada por cambios degenerativos oseos

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    Marchegiani, Silvio; Guzman Urquhart, Romel; Marangoni, Alberto; Alvarez, Federico; Surur, Alberto [Sanatorio Allende, Cordoba (Argentina). Servicio de Diagnostico por Imagenes

    2006-07-01

    Purpose: The temporomandibular dysfunction is a common pathology. It appears with many symptoms as: joint pain, mechanic disturbance, and loss of mouth motion. The Magnetic Resonance Image is the chose method to study these alterations. The purposes of this paper are to demonstrate according to sex, the distribution of temporomandibular dysfunction and to determinant the relationships between the disc dislocation and the degenerative disease of the junction. Material and Method: 215 patients were evaluated between January 1999 and August 2004. An Elscint MRI 2 Tesla machine was used with Spin-echo (T1 and T2) Fat-sat sequences, in coronal, axial and sagittal planes. The follow alterations were evaluated: dislocation, degenerative disease of articular surface, osteochondritis, discal perforation, and retrodiscal lesions. Results: 175 of all showed pathologic alterations in IRM examination. The other 40 patients were excluded due to present a normal (MRI) study. The patients were 146 females and 29 men. The most common dislocation site was the anterior. Performance of the IRM was useful in all the cases to demonstrate degenerative changes in the temporomandibular joint (TMJ). And was a very precise relationship between the dislocation and degenerative disease of the joint. Conclusion: the female patient is the most frequently affected by temporomandibular joint pathology. The IRM is the selection method to study the TMJ. The degenerative changes are responsible for joint dislocation without reduction. (author) [Spanish] Proposito: Las disfunciones temporomandibulares son muy frecuentes. Los sintomas pueden ser: dolor a nivel de la articulacion, alteracion en la traslacion discocondilar (chasquido) y dificultad en la apertura bucal; dichos problemas conllevan a una consulta creciente de medicos clinicos como de odontologos. En la actualidad la Imagen por Resonancia Magnetica Nuclear (RM) es el estudio de eleccion. Los objetivos de este trabajo fueron demostrar la

  7. Magnetic resonance imaging of the larynx; Resonancia magnetica de la laringe

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    Oleaga, L. [Hospital de Basurto. Bilbao (Spain)

    2001-07-01

    Larynx and hypopharynx represent difficult anatomical structures to evaluate by imaging. Pathological processes inflammatory conditions and neoplasms are frequently found specially neoplasms. The most common tumor originating in this region is squamous cell carcinoma that represents 90%, of malignancies, magnetic Resonance Imaging (MRI) is used for staging of those tumors. In our study we evaluate the technique used for MRI studies as well as the anatomy of the larynx, hypopharynx and nodes and the different classification system used for neck nodes. We also analyze the different types of neoplasm that can be found being and malignant and the use of MRI for staging neoplasms. Clinical and laryngoscope staging of laryngeal tumors is not accurate if fails to demonstrate deep submucosal and laryngeal spaces invasion (pre-epi glottic. para laryngeal, para glottic, anterior commissures posterior commissure and sub glottis) as well as cartilage infiltration and extra laryngeal extension. We need accurate imaging diagnostic methods like MRI to evaluate the extension of tumors. (Author) 38 refs.

  8. Stating of cervical carcinoma using magnetic resonance imaging; Estadificacion del carcinoma de cervix por resonancia magnetica

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    Oleaga, L.; Vela, M. C.; Grande, J.; Cura del, J. L.; Grande, D. [Hospital de Basurto. Bilbao (Spain)

    1999-07-01

    The infiltration of the parametrium represents one of the most important factors that determine the prediction and treatment of cervical carcinoma. Our objetive is to evaluate the utility of magnetic resonance imaging (MRI) in the staging of cervical carcinomas, to establish the reliability of this technique and to carry out a comparative study of the sequences used to demonstrate the parametrial invasion. We have carried out a retrospective study on 44 patients diagnosed with cervix neoplasia, using clinical exploration and performing a biopsy. the MRI studies have been carried out using a 1 Tesla magnet and the sequences used have been SE T1, Se proton density (PD) and T2 and dynamic GRE after administering gadolinium intravenously in the axial and sagital projections. The stages determined by MRI have been compared to the anatomopathological stages of the surgical specimens in cases where surgery was carried out and with the clinical stage in cases where no radical surgery was carried out. A diagnosis value of MRI has been determined to demonstrate the parametrial invasion, comparing the SE T2 sequence with the dynamic GE sequence with gadolinium. We calculate the volume of the tumour in the MRI studies to evaluate the difference of the volume between patients with tumoral stages that are clinically surgical and not surgical. MRI determines the invasion of the parametrium with a sensitivity of 88.8%, a specificity of 80% a positive value of 76.1%, a negative predictive value of 90.9% and a reliability of 83.7%. For the SE T2 sequences the sensitivity was 86.6%, the specifity 80%, the posistive predictive value 81.25%, the negative predictive value 85.7% and the reliability 83.3%. For the dynamic GE sequence with intravenous gadolinium the sensitivity was 86.6%, the specifity 86.6%, the posistive predictive value 86.6%, the negative predictive value 86.6% and the reliability 86.6%. The use of the dynamic GE sequence after the intravenous administration of gadolinium in patients with negative SE T2 sequence for the infiltration of the parametrium increased the negative predictive value of the combination of both series to 95.7%. The volume average of the tumor in patients with clinically surgical stages was 14.21 cm''3 and the average in patients with non surgical stages was 69.79 cm''3, the difference was statistically significant (p<0.0001). In the diagnosis of parametrial invasion, in the cervix carcinomas the SE T2 sequences have shown a high reliability. the use of gadolinium intravenously can improve the negative predictive value of the test, allowing to decide which patients need surgery with greather reliability. (Author) 18 refs.

  9. Functional magnetic resonance maps obtained by personal computer; Mapas de resonancia magnetica funcional obtenidos con PC

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    Gomez, F. j.; Manjon, J. V.; Robles, M. [Universidad Politecnica de Valencia (Spain); Marti-Bonmati, L.; Dosda, R. [Cinica Quiron. Valencia (Spain); Molla, E. [Universidad de Valencia (Spain)

    2001-07-01

    Functional magnetic resonance (fMR) is of special relevance in the analysis of certain types of brain activation. The present report describes the development of a simple software program for use with personal computers (PCs) that analyzes these images and provides functional activation maps. Activation maps are based on the temporal differences in oxyhemoglobin in tomographic images. To detect these differences, intensities registered repeatedly during brain control and activation are compared. The experiments were performed with a 1.5-Tesla MR unit. To verify the reliability of the program fMR studies were carried out in 4 healthy individuals (12 contiguous slices, 80 images per slice every 3.1 seconds for a total of 960 images). All the images were transferred to a PC and were processed pixel by pixel within each sequence to obtain an intensity/time curve. The statistical study of the results (Student's test and cross correlation analysis) made it possible to establish the activation of each pixel. The images were prepared using spatial filtering, temporal filtering, baseline correction, normalization and segmentation of the parenchyma. The postprocessing of the results involved the elimination of single pixels, superposition of an anatomical image of greater spatial resolution and anti-aliasing. The application (Xfun 1.0, Valencia, Spain) was developed in Microsoft Visual C++5.0 Developer Studio for Windows NT Workstation. As a representative example, the program took 8.2 seconds to calculate and present the results of the entire study (12 functional maps). In the motor and visual activation experiments, the activation corresponding to regions proximal to the central sulcus of the hemisphere contralateral to the hand that moved and in the occipital cortex were observed. While programs that calculate activation maps are available, the development of software for PCs running Microsoft Windows ensures several key features for its use on a daily basis: it is easy to employ and has powerful computing capabilities. The program described here is capable of differentiating between the regions of the brain that are activated in response to a stimulus and those that remain unaltered. (Author) 19 refs.

  10. Magnetic resonance in the dilation of terminal ventricle; Resonancia magnetica en la dilatacion del ventriculo terminal

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    Eulatem d, R. G.; Martinez, M. E.; Oleaga, L.; Grande, D.

    2001-07-01

    Describe de Magnetic Resonance (MR) findings in four cases of terminal ventricle dilation. We have studied four patients, all of them women, whose mean age range was 39 years. The studies were performed with a 1 Tesla magnet and the sequences used were sagittal and axial T1 and T2 weighted and sagittal and axial T1 weighted after the administration of gadolinium. the follow-up was clinical and by MRI. The four patients studied came due to low back pain. The MRI images demonstrated the presence of a cystic lesion located in the medullary cone, with a well defined contour and one that presented no type of enhancement in the study performed with gadolinium. In three cases, we had a MRI control at two years and the images had not varied. We have no control for the fourth cases of more recent diagnosis. The terminal ventricle is an ependymoma cavity located in the medullary cone. It can present a dilation and it is necessary to know its existence, typical location and signal characteristics to be able to diagnose and differentiate it from cystic tumors in this localization, that can present a similar appearance in the MRI. (Author) 7 refs.

  11. Quantitative analysis of water heavy by NMR spectroscopy; aplicacion de la resonancia magnetica nuclear al analisis cuantitativo de agua pesada

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    Gomez Gil, V

    1975-07-01

    Nuclear Magnetic Resonance has been applied to a wide variety of quantitative problems. A typical example has been the determination of isotopic composition. In this paper two different analytical methods for the determination of water in deuterium oxide are described. The first one, employs acetonitril as an internal standard compound and in the second one calibration curve of signal integral curve versus amount of D{sub 2}O is constructed. Both methods give results comparable to those of mass spectrometry of IR spectroscopy. (Author) 5 refs.

  12. Resonancias Vocales y Memoria Sonora en Helen Brown

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    Andrés Grumann Sölter

    2016-09-01

    Full Text Available El artículo se concentra en indagar aspectos referidos a la intensificación de los usos de la voz y la sonorización musical que proponen Trinidad Piriz y Daniel Marabolí en Helen Brown (2013. Dando cuenta de un marco teórico que cuestiona la dimensión referencial con la que se analiza frecuentemente al teatro y proponiendo una aproximación fenomenológica que dé cuenta de la materialidad performativa que insta a intensificar las resonancias de la voz y la capacidad audible del sonido, el escrito analiza dos escenas o tracks en los que la memoria hecha cuerpo compromete de un modo particular a los espectadores que participan de la performance escénica.

  13. Gadolinium Magnetic resonance with a diagnosis of Bell's facial palsy. Resonancia magnetica con gadolinio en el estudio de las paralisis de Bell

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    Rovira Caellas, A.; Sanchez Torres, C.; Navarrete, M.; Grive Isern, E.; Capellades Font, J.; Navarrete, M. (Hospital General Universitario Vall d' Hebron. Barcelona (Spain))

    1993-01-01

    The intratemporal pathway of the facial nerve has been prospectively studied by means of gadolinium MR in 12 patients with a diagnosis of Bell's facial palsy. All the cases presented total facial paralysis and were studied in the acute phase of the disease. With MR, the intratemporal pathway of the facial nerve has been viewed before and after the administration of a paramagnetic contrast medium, revealing uptake involving mainly the labyrinthine segment and the geniculate ganglion in every case. In no case did the MR findings influence the therapeutic approach, nor did they provide information of prognostic value. Therefore, this exploration is not considered necessary in the assessment of typical facial paralyses. The possible advantages of an MR study with contrast medium in facial paralysis specially apply to those cases with atypical clinical presentation, making it possible to establish a positive diagnosis, ruling out other lesions that may have a similar clinical presentantion. Thus, for the time being, a diagnosis of Bell's paralysis is not necessarily an exclusion diagnosis. (Author)

  14. Non Hodgkin lymphoma metastasis to the heart detected by cardiovascular magnetic resonance; Metastasis cardiaca secundaria al linfoma de Hodgkin detectada por la resonancia magnetica cardiovascular

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    Martinez, Florange; Morales, Marisela; Pedreanez, Norma [Hospital Cardiologico Infantil Latinoamericano Dr Gilberto Rodriguez Ochoa, Carcacas (Venezuela, Bolivarian Republic of); Pabon, Luz; Carrillo, Milton [Universidad Central de Venezuela (UCV/HUC), Caracas (Venezuela, Bolivarian Republic of). Instituto de Hematoncologia. Hospital Universitario; Fernandes, Juliano Lara [Universidade de Campinas (UNICAMP), SP (Brazil)

    2009-10-15

    Primary and secondary heart tumors are relatively rare occurrences but usually imply significant treatment decisions. The differential diagnosis among these tumors and other masses can sometimes be difficult and require the use of different imaging modalities to establish a confident verdict. Cardiovascular magnetic resonance CMR imaging is a very useful tool in these cases by allowing for the application of different strategies to better delineate masses, heart structures and adjacent tissues. In this case description, we present a woman with shortness of breath and a paracardiac mass showing how CMR can be applied. (author)

  15. Endometrial carcinoma: merit of magnetic resonance in pre-surgical staging; Carcinoma de endometrio: valor de la estadificacion prequirurgica por resonancia magnetica

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    Fernandez, E.; Barrera, M. C.; Gervas, C.; Salvador, E.; Rivero, B. [Hospital Donostia. San sebastian (Spain); Sentis, M. [Corporacio Sanitaria Pare Tauli. Sabadell (Spain)

    2003-07-01

    To evaluate MR capacity in assessing deep myometrial and cervical infiltrations in cases of endometrial carcinoma. A series of 30 consecutively diagnosed endometrial cancer patients was pre-surgically evaluated by means of magnetic resonance (MR). TSE-T2 sequences with fat saturation and dynamic FFe sequence were used after gadolinium administration. A correlation with post-surgical histological stating was made. There were then determined sensitivity (S), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) for the deep myometrial infiltration and cervical invasion. Cases of overestimation and underestimation were analyzed. Values obtained for myometrium and cervix were, respectively, S of 67% and 63%, SP of 89% and 91%, PPV of 80% and 71% and NPV of 80% and 87%. Two cases each were over valued for myometrial infiltration and cervix: four cases and 3 cases, respectively, were undervalues. MR stating in cases of endometrial carcinoma is a highly reliable diagnostic technique, but it does present certain limitations. (Author) 19 refs.

  16. The inappropriate use of lumbar magnetic resonance imaging in a health service area; Utilizacion inapropiada de la resonancia magnetica lumbar en un area de salud

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    Rodriguez Recio, F. J.; Sanz, J. C.; Vera, S. [Hospital General de Soria (Spain); Peiro, S. [Fundacion de Investigacion en Servicios de Salud Valencia (Spain)

    1999-07-01

    To identify the percentage of inappropriate lumbar spine magnetic resonance imaging in the Soria Health Service, to quantify the costs and the possible association between inadequate use, the characteristics of the patient and the services requested. A descriptive study of the inappropriate use of MRI of the lumbar spine, taken from the retrospective examination, carried out by a radiologist, of the 233 MRI's requested between 1995 and 1998. For the valuation, the criteria of the American College of Radiology (ACR) and the Basque Agency for the Evaluation of Technologies (OSTEBA) were used. All the MRI's were carried out at an approved centre, the costs were calculated taken form the expenses paid by the Insalud, including the transport costs, calculated at prices applicable for the year in question. 11.7% of the studies were values as inappropriate, 2.1% debatable and the remainder adequate according to the ACR criteria, concentrating the inadequacy on studies for lumbago, that reached 80% of the inappropriate requests. The ACR and OSTEBA criteria coincided to a high degree (kappa statistics: 0.87). The expense related to the unnecessary studies was a litter higher than a million pesetas. No differences were found in the proportion of inappropriate studies according to the characteristics of the patient or the service requested, except the one already mentioned for the supposition diagnosis. Although the results of the study cannot be generalised to other environments, they suggest the possibility of a significant proportion of inappropriate use of lumbar spine MRI that could have an important repercussion on health care expenses. (Author) 11 refs.

  17. First steps in quality control equipment MRI; Primeros pasos en el control de calidad de equipos de imagen por resonancia magnetica

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    Alonso Diaz, M.; Castaneda Arronte, M. J.; Ferreiros Vazquez, N.; Sanchez Merino, G.

    2011-07-01

    The present work aims to develop the initial stages of a program of quality control of nuclear magnetic resonance equipment. Not intended to conduct a comprehensive study covering all aspects of quality control, but gather the steps are followed and the most common problems they are encountering during the development of this program. It has been claimed that the work will be helpful to others facing the same task. Have been studied the compatibility of mannequins and procedures for the various teams. Ideally, such controls should be independent of the procedures and mannequins own commercial houses.

  18. Spontaneous intracranial hypotension syndrome: magnetic resonance findings in two patients; Sindrome de hipotension intracraneal espontanea: hallazgos en resonancia magnetica en dos pacientes

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    Ortega, R.; Pastor, J.; Escamilla, F.; Romero, M. I. [Hospital de Traumatologia y Reabilitacion. Granada (Spain)

    1999-07-01

    The postural headache syndrome associated with a decrease in the cerebrospinal fluid (CSF) pressure is generally secondary to the CSF leakage that usually occurs after diagnostic lumbar puncture. Spontaneous intracranial hypotension can not be attributed to any known cause or previous diagnostic or therapeutic intervention. The syndrome is characterized by severe headache that is relieved by lying supine. During lumbar puncture, the CSF pressure is normally low. We present two patients in whom gadolinium-enhanced magnetic resonance imaging showed widespread thickening and enhancement of the dura mater and subdural fluid collections. (Author) 13 refs.

  19. Non-traumatic acute epidural spinal hematomas diagnosed by magnetic resonance; Hematomas espinales epidurales agudos no traumaticos: diagnostico por resonancia magnetica

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    Rovira, A.; Grive, E.; Pedraza, S.; Capellades, J.; Nos, C.; Alarcon, M.; Rovira, A. [Hospital Universitari Vall d' Hebron. Barcelona (Spain)

    2000-07-01

    The non-traumatic spinal epidural hematoma (NTSEH) is a rare entity that can be the cause of an acute spinal compression syndrome. the objective of this review is to identify the characteristics by MRI and NTSEH and to analyze the factors that influence in its prognosis. In the years 1994 and 1999, 12 patients with NTSEH have been diagnosed in our hospital, and a MRI was performed during the acute phase. the characteristics of the lesions have been analyzed by MRI, with special emphasis on the topographic data and resonance signal and the factors that can influence in the clinical prognosis of the patients. Initially, all of the patients presented pain in the cervical dorsal or interscapular site, followed by a sensitive-motor deficit picture. The MRI showed a lesion of expansive character and posterior epidural location in every case that would produce varying degrees of compression on the spinal cord. The NTSEH should be considered as one of the causes of acute spinal cord compression. The clinical association of intense cervical, dorsal or interscapular pain followed by a sensomotor deficit picture should lead to the suspicion of this entity, that would require an immediate examination with MRI to verify its diagnosis. Both the clinical manifestations as well as the characteristics observed by MRI of the NTSEH have a prognostic value and determine the therapeutic decision. (Author) 34 refs.

  20. Usefulness of magnetic resonance in the evaluation of perianal fistulas; Utilidad de la resonancia magnetica en la valoracion de las fistulas perianales

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    Campo, M.; Isusi, M.; Oleaga, L.; Grande, D. [Hospital de Basurto. Bilbao (Spain); Fernandez, G.; Tardaguila, F. [Clinica POVISA. Vigo (Spain)

    2003-07-01

    Our aim was to confirm the usefulness of magnetic resonance in the evaluation of perianal fistulas, and in conjunction with a thought anatomical review of affected areas. This would allow for the building of a proper surgical plan, which would necessarily differ according to the fistula's complexity. We studied 75 patients with perianal fistulas and performed 81 MR studies by means of axial, sagittal and coronal T1 and T2 sequences. Fistula type, degree, etiology and correlation to surgical findings were all studied. Fifty-five patients underwent surgical treatment, and 26 underwent a more conservative treatment with MR follow-up. Ninety-nine fistulas were observed and classified according to norms set down by St. James University Hospital. Of the 55 cases submitted to surgery, 46 showed concordance between the surgical report and MR, whose sensitivity was 84%. In 9 patients, there was no correlation. In the study of perianal fistulas, it is important to establish both the fistulous tract and relationship to the sphincter complex. MR permits an identification of the sprinter complex and a more precise anatomical localization of the fistulous trajectory. It is also capable of differentiating between fibrosis and abscess. Therefore, MR is an appropriate technique for the study of perianal fistulas and related surgical planning. (Author) 6 refs.

  1. Synovial hemangiomas of the knee: magnetic resonance findings in six cases; Hemangiomas sinoviales de rodilla: hallazgos de la resonancia magnetica en seis casos

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    Concepcion, L.; Marti-Bonmati, L. M.; Dosda, R. [Hospital Dr. Peset. Valencia (Spain); Llauger, J.; Palmer, J. [Hospital Santa Creu i Sant Pau. Barcelona (Spain); Mellado, J. M. [Inscanner, S. L. Alicante (Spain)

    1999-05-01

    The synovial hemangioma is an uncommon benign vascular tumor that is difficult to diagnose on the basis of clinical signs Moreover, it has no characteristic radiographic features. The objective of the present report was to describe the MR findings associated with synovial hemangioma of the knee. We review the clinical and MR findings in six patients, with histologically confirmed synovial hemangioma of the Knee, studied with different MR systems and techniques. Synovial hemangiomas were isointense with respect to muscle in T1-weighted images, strongly hyperintense in T2-weighted sequences and presented wavy hypointense linear images. Gadolinium administration resulted in a marked enhancement, although it was heterogeneous in two of three cases analyzed. Although the findings are not pathognomonic, the presence of an intraarticular tumor of the knee that is isointense with respect to muscle in T1 and hyperintense in T2, and shows wavy hypointense images and a marked contrast uptake, may suggest the presence of synovial hemangioma. (Author) 11 refs.

  2. The use of Magnetic Resonance Sounding in shallow aquifers IN THE Duero RIVER Basin; Aplicacion de sondeos de resonancia magnetica en acuiferos superficiales de la Cuenca del Duero

    Energy Technology Data Exchange (ETDEWEB)

    Uriarte Blanco, C.; Plata Torres, J. L.; Diaz-Curiel, J.; Martinez-Fernandez, J.

    2011-07-01

    To manage the water resources of a region efficiently it is vital to be aware of the dynamics and evolution of its groundwater. To this end groundwater models are used, but these models require information about the geometry and hydraulic parameters of the aquifer, which is generally quite expensive to obtain. Magnetic resonance sounding (MRS) is a non-invasive geophysical technique that allows an aquifer to be characterized. Our intention here is to assess the use of this geophysical technique to optimize the acquisition of data when preparing a hydrological model of surface aquifers in the Duero Basin. The study was undertaken in the Experimental Basin of Carrizal, within the Los Arenales aquifer in the Duero Basin. We present a detailed analysis and interpretation of the MRS results, which have provided us with information concerning the parameters needed to establish a hydrological model of the aquifer, information that may be used eventually as an input to obtain a hydrological model of the whole basin. (Author)

  3. Magnetic resonance in the diagnostic imaging study of mesial temporal sclerosis; Diagnostico por imagen con resonancia magnetica de la esclerosis temporal mesial

    Energy Technology Data Exchange (ETDEWEB)

    Pastor, E; Sanchez, J C; Rodriguez, I; Altuzarra, A; Machado, F [Hospital Universitario Virgen de las Nieves. Granada (Spain); Aguilar, D [Hospital Clinico Universitario San Cecilio. Granada (Spain)

    2001-07-01

    Mesial temporal sclerosis (MTS) consists of hippocampal atrophy and gliosis and is the most common cause of temporal lobe epilepsy. The objective of the authors was to establish a magnetic resonance imaging (MRI) protocol for its diagnosis. A prospective study was carried out in 72 patients with drug resistant complex partial seizures (42 women and 30 men ranging in age from 6 to 66 year: mean: 30 years). Using a 1.5-Tesla magnet, paracoronal sections were made in hippocampi for T1-weighted inversion-recovery images and volume measurements, fluid-attenuated inversion-recovery (FLAIR) and T2 relaxometry. A control group of 30 health volunteers was included in the study. MTS was considered to be indicated by the presence of atrophy and hyperintensity in hippocampi on T2-weighted images. There were no differences among the hippocampi of the healthy individuals. The confidence intervals (mean{+-} 1.96 SD) were 4169 mm''3-5911 mm''3 for volume of right side, 4097 mm''3-5940 mm''3 for volume of left side and 98-113 ms for T2 relaxation time. MTS was detected in 40 patients (55.5%): 23 cases involving the left side, 13 involving the right and 4 cases of bilateral asymmetric involvement. The 95% confidence intervals for the diagnostic validity of the results (sensitivity/specificity) were (88.8%-97.2%)/(87.6%-96.4%) for T1 volumetry, (88.8%-97.2%)(95.7%-100.3%) for FLAIR and (85.4%-96.6%)/(85.4%-96.6%) for T2 relaxometry. In 5 cases of MTS, astrophy of other extra hippocampal structures was also observed, and MTS was associated with an extra hippocampal lesion (dual pathology), especially neurona migration disorders, in 8 patients. Seventeen patients (23.5%) presented lesions without MTS (tumors, cortical dysplasias and heterotopias) and there was no MRI evidence of anomalies in 15 (21%). Twenty-five patients underwent surgical treatment: 20 with MTS (19 diagnosed according to MRI and one in whom there had been no abnormal findings), 4 with tumors and 1 with a ballooned cell cortical dysplasia. (Author) 50 refs.

  4. Magnetic resonance in the diagnostic imaging study of mesial temporal sclerosis; Diagnostico por imagen con resonancia magnetica de la esclerosis temporal mesial

    Energy Technology Data Exchange (ETDEWEB)

    Pastor, E.; Sanchez, J. C.; Rodriguez, I.; Altuzarra, A.; Machado, F. [Hospital Universitario Virgen de las Nieves. Granada (Spain); Aguilar, D. [Hospital Clinico Universitario San Cecilio. Granada (Spain)

    2001-07-01

    Mesial temporal sclerosis (MTS) consists of hippocampal atrophy and gliosis and is the most common cause of temporal lobe epilepsy. The objective of the authors was to establish a magnetic resonance imaging (MRI) protocol for its diagnosis. A prospective study was carried out in 72 patients with drug resistant complex partial seizures (42 women and 30 men ranging in age from 6 to 66 year: mean: 30 years). Using a 1.5-Tesla magnet, paracoronal sections were made in hippocampi for T1-weighted inversion-recovery images and volume measurements, fluid-attenuated inversion-recovery (FLAIR) and T2 relaxometry. A control group of 30 health volunteers was included in the study. MTS was considered to be indicated by the presence of atrophy and hyperintensity in hippocampi on T2-weighted images. There were no differences among the hippocampi of the healthy individuals. The confidence intervals (mean{+-} 1.96 SD) were 4169 mm''3-5911 mm''3 for volume of right side, 4097 mm''3-5940 mm''3 for volume of left side and 98-113 ms for T2 relaxation time. MTS was detected in 40 patients (55.5%): 23 cases involving the left side, 13 involving the right and 4 cases of bilateral asymmetric involvement. The 95% confidence intervals for the diagnostic validity of the results (sensitivity/specificity) were (88.8%-97.2%)/(87.6%-96.4%) for T1 volumetry, (88.8%-97.2%)(95.7%-100.3%) for FLAIR and (85.4%-96.6%)/(85.4%-96.6%) for T2 relaxometry. In 5 cases of MTS, astrophy of other extra hippocampal structures was also observed, and MTS was associated with an extra hippocampal lesion (dual pathology), especially neurona migration disorders, in 8 patients. Seventeen patients (23.5%) presented lesions without MTS (tumors, cortical dysplasias and heterotopias) and there was no MRI evidence of anomalies in 15 (21%). Twenty-five patients underwent surgical treatment: 20 with MTS (19 diagnosed according to MRI and one in whom there had been no abnormal findings), 4 with tumors and 1 with a ballooned cell cortical dysplasia. (Author) 50 refs.

  5. Multiple sclerosis and anterograde axonal degeneration study by magnetic resonance. Asociacion de esclerosis multiple y degeneracion Walleriana estudio por resonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Pardo, P; Capdevila Cirera, A; Sanz Marin, P M; Gili Planas, J [Centro de Resonancia Magnetica de Barcelona (Spain)

    1993-01-01

    Multiple sclerosis (MS) is a disease of the central nervous system that affects specifically the myelin. Its diagnosis by imaging techniques is, since the development of magnetic resonance (MR), relatively simple, and its occasional association with anterograde axonal degeneration (WD) has been reported. In both disorders, there is a lengthening of the T1 and T2 relaxation times. In the present report, 76 patients with MS with less than 4 plaques in the typical periventricular position were studied retrospectively, resulting in a rate of association with anterograde axonal degeneration of 8%. We consider that in spite of their same behavior in MR,MS and WD, with moreover represent completely different pathologies, are perfectly differential by MR. The S-E images with longer repetition and echo times in the axial and coronal planes have proved to be those most sensitive for this differentiation. Given that MS is specific pathology of then myelin, the axonal damages in delayed until several plaques adjacent to an axon affect it. We consider that this, added to the restriction of our study group (less than 4 plaques), is the cause of the pow percentage of the MS-WD association in our study. (Author).

  6. Continuous partial status cause of hyperintensity in cerebral cortex in magnetic resonance imaging; Estatus parcial continuo, causa de hiperintensidad de la corteza cerebral en la resonancia nuclear magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Lopez L, Ingeborg; Gonzalez L, Daniela [Departamento de Ciencias Neurologicas Oriente. Facultad de Medicina, Universidad de Chile, Santiago (Chile); Quezada R, Patricio [Servicio de Neurologia, Hospital Salvador, Santiago (Chile); Cartier R, Luis [Departamento de Ciencias Neurologicas Oriente. Facultad de Medicina, Universidad de Chile, Santiago (Chile)

    2012-07-01

    Magnetic Resonance Imaging has demonstrated functional changes of the cerebral cortex in relation to status epilepticus, which can eventually localize the origin of the crisis. The purpose of this presentation is relevant to this condition and pretends to highlight the action of incidental situations that can modify it. We present a 29 year old woman with a neurosurgical intervention for a neuroblastoma irradiated fifteen years ago, which incidentally starts a continuous partial status epilepticus, expressed by clonies of the face and left limbs associated with functional impotence, resistant to oral therapy. Faced with the suspicion of recurrence of the tumor, a brain MRI is performed, showing hyperintensity of all neural areas the right hemisphere, with no evidence of tumor recurrence. Once submitted the status epilepticus, the hyperintensity disappeared in the hemisphere. This extensive reaction of the neural structures might be related to a permanent effect of radiation, which may have caused a mismatch functional glia, of the blood-brain barrier and interneural network.

  7. Iconografía por Resonancia Magnética

    Directory of Open Access Journals (Sweden)

    Jaime Gómez Gonzalez

    1987-04-01

    Full Text Available

    Iconografía, del griego “eikon” imagen y “graphein” dibujar, es la ciencia de las imágenes. La reproducción de imágenes del cuerpo humano puede hacerse por muchos medios, el más reciente, la Resonancia Magnética. Se trata de un procedimiento bien conocido por los químicos desde hace casi cuatro decenios y que se emplea para el análisis espectrográfico de cualquier substancia.

    Hace menos de diez años Raymond Damadian pudo utilizar este sistema para producir imágenes de cortes tomográficos del cuerpo humano en cualquier plano, sin utilizar radiaciones ionizantes. El perfeccionamiento del equipo ha llegado en los últimos tres años a producir imágenes con detalles anatómicos de gran perfección. Existe la posibilidad de hacer análisis espectrográfico en vivo, pero este procedimiento se encuentra aún en investigación.

    Para evaluar el sistema, el autor ha visitado varias fábricas en Europa y Estados Unidos, un número importante de laboratorios de centros hospitalarios en Nueva York, Houston, La Florida, y contribuyó a organizar en la Fundación Instituto Neurológico de Colombia, en colaboración con el Centro Internacional de Física, el I Seminario Internacional sobre Iconografía por Resonancia Magnética en abril de 1986, con participación de conferenciantes de Alemania, Bélgica, Dinamarca y los Estados Unidos.

    Se han compilado los informes de unos quince fabricantes, cuatro de ellos con representación en Colombia; se solicitaron cotizaciones, se realizaron estudios económicos y se consultó con arquitectos para adecuar el sitio donde se podría instalar el equipo en la Fundación Instituto Neuro lógico de Colombia, como un servicio más a la comunidad. En este momento se programa para 1987, el 11Seminario Internacional de Iconografía por Resonancia Magnética.

    El principio utilizado para obtener estas imágenes se basa en conceptos físicos muy complejos; sin embargo, se pueden

  8. Sensores de fibra óptica basados en resonancias electromagnéticas

    OpenAIRE

    López Lambás, Sergio

    2011-01-01

    Este trabajo surge como continuación a los trabajos basados en LMR ya realizados con el objetivo de profundizar en el estudio y fabricación de sensores de fibra óptica basados en resonancias electromagnéticas utilizando diferentes materiales y técnicas. En concreto el proyecto perseguirá los siguientes objetivos: Desarrollar sensores de fibra óptica basados en resonancias electromagnéticas con recubrimientos metálicos y su aplicación a la detección de campo magnético. Estudiar y mejorar la fa...

  9. Estudio del efecto del filtrado en resonancia magnética de difusión

    OpenAIRE

    Rubio Álvarez, Jorge

    2015-01-01

    En el mundo de la medicina, las imágenes de resonancia magnética de difusión (dMRI) son una herramienta de diagnóstico fundamental ya que nos proporcionan la posibilidad de visualizar los sistemas de fibras nerviosas que componen la sustancia blanca del cerebro. El inconveniente de esta herramienta es que los datos de las imágenes de resonancia magnética de difusión se ven damnificados por diversas fuentes de ruido que, irremediablemente, merman la calidad de las adquisiciones. Este ruido lo ...

  10. Resonancia magnética cardiaca: medidas lineales y volumétricas en adultos sanos

    OpenAIRE

    Heredia Sánchez, Fabian Mauricio; Cabezas, Andrés Mauricio

    2015-01-01

    Introducción: La gran mayoría de las medidas de normalidad utilizadas para la interpretación de resonancia cardiaca son extrapoladas de las medidas de ecocardiografía. Los limitados registros de medidas de normalidad se encuentran ajustados en poblaciones extranjeras, no hay registros en latinoamericanos. Objetivo: Determinar las dimensiones cardiacas utilizando resonancia magnética en una población de personas sin antecedente médicos con repercusión cardiaca para lograr una muestra de val...

  11. Estenosis aórtica pura y resonancia magnética en el adulto

    OpenAIRE

    Meave-González, Aloha; Alexánderson, Erick; Hernández-González, Martha A; Siu, Silvia; Soto, Ma. Elena; Solorio, Sergio; Espínola-Zavaleta, Nilda

    2007-01-01

    Objetivos: Evaluar la utilidad de la resonancia magnética cardiovascular (RMC) para la cuantificación del área valvular aórtica en pacientes adultos con estenosis aórtica pura (EA). Método: Estudio transversal comparativo, cegado, en pacientes con estenosis aórtica, sin otra patología valvular asociada, en quienes se realizó ecocardiograma transtorácico bidimensional (ETT) y resonancia magnética. Los resultados se analizaron mediante t de Student, ji cuadrada considerando como significativos ...

  12. Resonancia magnética funcional Functional magnetic resonance

    Directory of Open Access Journals (Sweden)

    Erick Sell

    2007-01-01

    Full Text Available La resonancia magnética funcional (RMNf es un estudio no invasivo de mapeo funcional cerebral, cuya señal obtenida en secuencias T2* es dependiente del nivel de oxigenación sanguínea (BOLD. Este estudio se agrega actualmente a otros muchos empleados en el abordaje de pacientes candidatos a cirugía de epilepsia, para localizar lenguaje y función motriz previa a planear la cirugía. Tiene una concordancia con el test de WADA de cerca del 90%. El uso concomitante de registro encefalográfico y RMNf es técnicamente difícil, pero una vez filtrados los artefactos presenta un patrón de activación significativamente discordante con el foco de actividad interictal. Este hallazgo podría obedecer a redes complejas de actividad epiléptica, y promete ser un útil instrumento en la investigación de la fisiopatología del tejido epileptogénico.Functional magnetic resonance imaging (fmri is a non-invasive functional brain mapping technique ased on blood oxygenated level dependent signal (BOLD. It is obtained during T2* weighted imaging MRI studies. fmri aids in the localization of language and motor function for patients candidates for epilepsy surgery, and has up to a 90% concordance with WADA test. Even though synchronous recording of fmri and EEG is technically challenging, it shows a discordant pattern of activation when compared with EEG or electrocorticography. This finding could be due to complex epileptic networks, and overall this study technique has the potential to contribute to further research into epileptic network and epilepsy physiopathology.

  13. Resonancia religiosa en México: Cifras básicas

    Directory of Open Access Journals (Sweden)

    Marco Ornelas

    2015-01-01

    Full Text Available El objetivo de esta nota es presentar información de membresía religiosa en México al año 2010, además de proporcionar la información oficial disponible sobre ministros de culto y asociaciones religiosas registrados en el país. Adicionalmente, intenta most rar una manera en que puede hacerse uso de estadísticas de membresía/adscripción religiosa dentro de la sociología religiosa luhmanniana, a partir del concepto de resonancia religiosa. La resonancia religiosa indica el porcentaje de la población que declar a su pertenencia a alguna religión, presuponiendo la existencia de un sistema de comunicaciones religiosas mundializado. A pesar de ser México un país con resonancia religiosa mayoritariamente católica (82.7%, no menos de 15 orientaciones religiosas disti ntas a la católica son distinguibles en el territorio nacional. El análisis estadístico presentado permite la sospecha fundada de una inflación de la resonancia católica en México.

  14. Registro multimodal de mamografías: resonancia magnética y rayos-x.

    OpenAIRE

    Solves Llorens, Juan Antonio

    2014-01-01

    Solves Llorens, JA. (2014). Registro multimodal de mamografías: resonancia magnética y rayos-x [Tesis doctoral no publicada]. Universitat Politècnica de València. doi:10.4995/Thesis/10251/38940. Alfresco

  15. Magnetic nanoparticles for cancer therapy; Nanoparticulas magneticas para o tratamento do cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bakuzis, Andris F. [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Instituto de Fisica

    2014-07-01

    Full text: Magnetic nanoparticles have been used in several biomedical applications, spanning from cell separation, early diagnosis of metastasis to even the treatment of cancer via magnetic hyperthermia (MH). This last technique consists in the increase of temperature of nanoparticles when their magnetic moments interact with a magnetic alternating field. This effect has been suggested as an innovative therapy to cancer treatment, due to the delivery of heat or therapeutic agents, such as drugs, genes, and others. In addition, several clinical studies has demonstrated synergetic effects between hyperthermia and radiotherapy [1]. This indicates a great therapeutic potential for this noninvasive and targeted technique. In this talk we will discuss results from the literature and from our own group in the treatment of cancer via magnetic hyperthermia. Several types of magnetic nanoparticles suggested for this application will be discussed, as well as the historical evolution of this procedure, which although suggested in the late 50' only recently was approved in Europe for treatment of humans with brain tumors. (author) [Portuguese] Full text: Nanoparticulas magneticas tem sido utilizadas em diversas aplicacoes biomedicas, desde a separacao de celulas, marcacao de celulas-tronco, diagnostico precoce de metastases ao tratamento do cancer via hipertermia magnetica (HM). Esta ultima tecnica consiste no aumento da temperatura de nanoparticulas quando seus momentos magneticos interagem de forma adequada com um campo magnetico alternado. Este efeito tem sido idealizado como uma nova terapia para o tratamento do cancro, seja via entrega seletiva de calor ou mesmo pela liberacao de farmacos, genes ou outros agentes terapeuticos por meio desta acao externa. Adicionalmente, diversos estudos clinicos tem demonstrado efeitos sinergicos entre a hipertermia e tecnicas tradicionais de tratamento oncologico, como quimioterapia e radioterapia. Isto indica um forte potencial

  16. Generalized principal resonance in oscillatory systems of second order; Resonancia principal generalizada en sistemas oscilatorios de segundo orden

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Aguirre, E. [Universidad Autonoma de Puebla, Oaxaca (Mexico); Alexandrov, V. V. [Benemerita Universidad Autonoma de Puebla, Puebla (Mexico)

    2001-02-01

    This paper will describe the generalized principal resonance of systems as described by the second order of ordinary differential equations and proved by the Pontriaguin maximal principle to coincide with the lengthened solution of an external problem of the same system. The results are verified in special cases of general resonance and parametric resonance for the Mathieu equation. [Spanish] En el presente articulo se estudia la resonancia principal generalizada para sistemas descritos por ecuaciones diferenciales ordinarias de segundo orden y se demuestra con ayuda del principio del maximo de Pontriaguin, la coincidencia de esta con la solucion prolongada de un problema extremal para el mismo sistema. Ademas se verifican estos resultados en los casos particulares de resonancia general y resonancia parametrica para la ecuacion de Mathieu.

  17. La imagen por resonancia magnética en el estudio de la esquizofrenia

    OpenAIRE

    Salgado Pineda, Pilar; Vendrell, Pere

    2004-01-01

    La resonancia magnética ha tenido una amplia aplicación en el ámbito de la esquizofrenia para investigar sus bases neuroanatómicas y funcionales. Los estudios estructurales han evolucionado desde las mediciones semiautomáticas de estructuras aisladas hasta las sofisticadas técnicas de análisis automático vóxel a vóxel, denominadas voxel-based morphometry. Actualmente, existen hallazgos consientes y confluentes sobre la existencia de diversas anomalías estructur...

  18. La resonancia magnética en el diagnóstico de la sialoadenosis parotidea

    OpenAIRE

    Paz, J.; Velasco-Ortega, Eugenio

    1997-01-01

    La resonancia magnética (RM) constituye una técnica exploratoria importante en el diagnóstico de la patología de cabeza y cuello. Recientemente, se ha incorporado al estudio de las glándula salivales, espcialmente la parótida. En el presente trabajo se presentan los hallazgos por RM en siete casos de sialoadenosis parotidea. Las imágenes por RM demuestran el agrandamiento glandular uni o bilateral, el incremento en el tamaño de las lesiones y el diagnóstico de los cambios en la estructura int...

  19. Estudio mediante resonancia magnética de efectos pretransicionales en cristales líquidos

    OpenAIRE

    Vaca Chavez, Fabián

    2002-01-01

    Tesis (Doctor en Física)--Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física, 2002. Se presenta el estudio mediante la técnica de Resonancia Magnética Nuclear de los efectos pretransicionales en diferentes fases de cristales líquidos termotrópicos y liotrópicos. Estos compuestos son materia de innumerables trabajos tanto teóricos como experimentales, debido a que son materiales extremadamente interesantes por sus aplicaciones tecnológicas, ópticas y biológicas. Se...

  20. Evidencia y neurociencias cognitivas: El caso de la resonancia magnética funcional

    Directory of Open Access Journals (Sweden)

    A. Nicolás Venturelli

    2015-12-01

    Full Text Available La resonancia magnética funcional es una de las técnicas de neuroimagen más difundidas en las neurociencias cognitivas. Su influencia tuvo un rol importante en la configuración del costado experimental de este campo. Frente a esto, consideramos que su estatus como evidencia no sido suficientemente discutido en la literatura filosófica. Aquí nos centramos sobre este punto desde la óptica de la tensión clásica sobre el alcance de los enfoques localizacionistas en neurociencias. Atendemos al modo en que esta tensión se manifiesta hoy. Tomamos en cuenta un número de limitaciones que presenta la resonancia magnética funcional y analizamos el modo en que los investigadores les hacen frente. En función de esto, sostenemos que existe una medida importante en que la técnica puede ser orientada sobre la base de supuestos y consideraciones teóricas generales. Para sustentar nuestras ideas, tomamos algunos ejemplos recientes de abordajes neurocientíficos caracterizados por abordar de manera directa el carácer dinámico de la actividad a gran escala en el cerebro.

  1. Resonancia ferromagnética en vidrios metálicos

    Directory of Open Access Journals (Sweden)

    García-Miquel, H.

    2000-06-01

    Full Text Available In the presently work ferromagnetic resonance (FMR of metallic glasses in microwires form of composition (FexCo1-x72.5 Si12.5 B15 has been measured. The ferromagnetic resonance frequency of amorphous magnetic microwires has been obtained from power absorption measurements in the microwave frequency range. The experimental technique here employed consists on the replacement of the dielectric of a coaxial transmission line by the sample to be measured. From the evolution of the resonance frequency with a dc applied magnetic field, the anisotropy field of the microwires has been deduced, and successfully compared to that obtained from quasi-static hysteresis loops.

    En el presente trabajo se ha medido la frecuencia de resonancia ferromagnética (FMR de vidrios metálicos en forma de microhilos de composición (FexCo1-x72.5 Si12.5 B15. Estos microhilos constan de un núcleo magnético de unas 5μm de diámetro y una cobertura de vidrio, siendo el diámetro total de entre 10 y 15 μm según la muestra. La técnica experimental empleada consiste en la sustitución del dieléctrico de una línea de transmisión coaxial por los microhilos a medir, y en la medida de la absorción de potencia a frecuencias de microondas. Para cada muestra se ha ido variando la intensidad de un campo externo de magnetización, provocando la variación de la frecuencia de resonancia. Con estas medidas se ha conseguido establecer la relación entre campo de magnetización y frecuencia de resonancia, y mediante el análisis de los datos obtenidos y contrastados con el modelo teórico propuesto se ha obtenido información del campo de anisotropía de los microhilos. Finalmente, el campo de anisotropía calculado se ha contrastado con el obtenido mediante la medida del ciclo de histéresis quasi-estático.

  2. Influence of high energy phosphate metabolism in postischemic myocardial dysfunction using magnetic resonance spectroscopy; Influencia dos fosfatos de alta energia na funcao ventricular em pacientes com infarto do miocardio avaliada pela resonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Kalil Filho, Roberto [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Hospital das Clinicas

    1998-05-01

    The recovery of left ventricular function after reperfusion is delayed in general by several hours, days or weeks and this phenomenon is known as myocardial stunning. One of the theories to explain the pathogenesis of this postischemic myocardial dysfunction is the production of not enough energy by mitochondria, leading to decreased adenosine-triphosphate (ATP) levels. We evaluated the influence of high energy phosphate metabolism in postischemic myocardial dysfunction, using magnetic resonance spectroscopy in patients with acute anterior wall myocardial infarction, successfully reperfused, within the first six hours from the onset of the symptoms. Twenty-nine patients were studied in the acute phase (on average four days after the onset of myocardial infarction) and 21 repeated the examination in the follow-up phase (average 39 days). Regional left ventricular function was evaluated by cine-resonance and high energy phosphate metabolism by phosphorus-31 spectroscopy, using the phosphocreatine {beta} ATP (P Cr/{beta}ATP) ratio. The existence of myocardial stunning was suggested by the improvement of the related regional contractility during the follow-up. The contractility improved in the septal wall from 2.46{+-} 0.68 to 1.54 {+-} 0.78 (p<0.001), in the anteroseptal wall from 2.0 {+-} 0.89 to 1.40 {+-} 0.75 (p<0.001) and in the anterior wall from 2.37 {+-} 0.71 to 1.41 {+-} 0.59 (p<0.001). The P Cr/{beta}ATP ratio did not change from acute to follow-up phase (1.51 {+-} 0.17 vs. 1.53 {+-} 0.17; p = 0.6). This study suggests that decreased high energy phosphate metabolism after reperfusion does not have an important role in the genesis of the myocardial stunning in patients with acute anterior wall myocardial infarction. (author) 25 refs., 9 figs., 1 tab.

  3. A prospective, comparative study of magnetic resonance cholangipancreatography and direct cholangiography in the diagnosis of biliary diseases; Estudio propsective comparativo en el diagnostico de la patologia biliar. Colangiopancreatografia por resonancia magnetica frente a colangiografia directa

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, E.; Falco, J.; Martin, J.; Brullet, E.; Campo, R.; Espinos, J.; Darnell, A.

    2001-07-01

    To assess the sensitivity and specificity of magnetic resonance cholangiopancreatography (MRCP) as a noninvasive diagnostic technique, comparing it with endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTHC) in the diagnosis of biliary disease, focusing particularly on patients with choledocholithiasis. Between June 1997 and february 1998, 109 patients referred by the Corporacio Sanitaria del Parc Tauli and the Hospital Mutua de terrasa in Barcelona, Spain were evaluated. MRCP and ERCP or PTHC were performed in every case, always in that order and separated by a maximum of 7 days. Twenty-four patients were excluded from the study for different reasons, leaving a series of 85 patients. All the studies were performed with a 1-Tesla Siemens Magneton Impact Expert using half-fourier single-short turbo spin-echo (HASTE) and rapid acquisition with relaxation enhancement (RARE) methods in several coronal and axial planes. The MRCP readings were carried out by consensus by two radiologists who are experts in the assessment of diseases of the digestive tract. In this series of 85 patients; MCRP showed a sensitivity of 98.4%, a specificity of 94.7%, a positive predictive value of 98.4% and a negative predictive value of 94.7% for the detection of biliary diseases. For the detection choledocholithiasis, these values were 100%, 89.5%, 88% and 100%, respectively. MRCP is extremely reliable in the diagnosis of biliary diseases, especially in cases of choledocholithiasis. Its high negative predictive value obviates the need for other invasive diagnostic tests. (Author) 30 refs.

  4. Complexity Index as Applied to Magnetic Resonance: Study Based on a Scale of Relative Units; Indice de complejidad en resonancia magnetica: estudio basado en una escala de unidades relativas

    Energy Technology Data Exchange (ETDEWEB)

    Capelastegui, A.; Villanua, J.

    2003-07-01

    To analyze the merit and repercussions of measuring magnetic resonance (MR) activity in units of radiological activity, and of using complexity index (CI) as an activity indicator. We studied the MR activity of Osatek, Inc. during an 8-year period (1994-2001). We measured this activity both in number of MR procedures performed and in units of radiological activity, such units being based on the scale of relative units published in the Radiological Services Administration Guidelines published by the Spanish Society or Medical Radiology. We calculated the annual complexity index, this being a quotient between the number of MR procedures performed and corresponding value in units of radiological activity. We also analyzed factors that can have an impact on the CI: type of exploration and power of the equipment's magnetic field. The CL stayed practically stable during the first 4 years of the study, while it increased during the second 4 years. There exists a direct relationship between this increase and the percentage of explorations that we term complex (basically, body-and angio-MR). The increasing complexity of MR studies in the last years is evident from a consideration of CI. MR productivity is more realistically expressed in units of radiological activity than in number of procedures performed by any one center. It also allows for making external comparisons. CI is a useful indicator that can be utilized as an administrative tool. (Author) 13 refs.

  5. Intelligent simulated annealing algorithm applied to the optimization of the main magnet for magnetic resonance imaging machine; Algoritmo simulated annealing inteligente aplicado a la optimizacion del iman principal de una maquina de resonancia magnetica de imagenes

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Lopez, Hector [Universidad de Oriente, Santiago de Cuba (Cuba). Centro de Biofisica Medica]. E-mail: hsanchez@cbm.uo.edu.cu

    2001-08-01

    This work describes an alternative algorithm of Simulated Annealing applied to the design of the main magnet for a Magnetic Resonance Imaging machine. The algorithm uses a probabilistic radial base neuronal network to classify the possible solutions, before the objective function evaluation. This procedure allows reducing up to 50% the number of iterations required by simulated annealing to achieve the global maximum, when compared with the SA algorithm. The algorithm was applied to design a 0.1050 Tesla four coil resistive magnet, which produces a magnetic field 2.13 times more uniform than the solution given by SA. (author)

  6. Design of a mannequin for spectroscopy magnetic resonance of proton. Preliminary results of its application; Diseno de un maniqui para espectroscopia por resonancia magnetica de proton. resultados preliminares de su aplicacion

    Energy Technology Data Exchange (ETDEWEB)

    Parra Osoirio, V.; Galan Montenegro, P.; Moreno Saiz, C.; Garcia-Alvarez, R.; Arrabal Nunez, S.; Caudepon Moreno, F.; Navarro Guirado, F.; Asensjo Garcia, B.

    2013-07-01

    The proton magnetic resonance spectroscopy is a technique of metabolic Imaging allowing in vivo measurement of the levels of different metabolites. Is under increasing development and has shown an improvement of diagnostic indexes and therapeutic, since it allows: differential diagnosis between injuries, determination of tumor grade of Pre surgical form, determination of the presence of a lesion until it is clear, definition of progress and evaluation of the effects of a treatment. The aim in this work is to have a mannequin that allows analyze and adjust various parameters involved in the spectroscopic process, and establish a quantification of these parameters. (Author)

  7. Qualitative characterization of free polyamines in ethyleneamines epoxide hardeners by nuclear magnetic resonance spectroscopy; Caracterizacion cualitativa de poliaminas libres en endurecedores de resinas epoxidicas del tipo etilenaminas por espectroscopia de resonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Garcia, Filiberto [Universidade Federal de Itajuba (UNIFEI), MG (Brazil); Miguez, Eduardo; Tavares, Maria Ines B. [Universidade Federal do Rio de Janeiro (UFRJ/IMA), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano

    2008-01-15

    The qualitative characterization of two commercial ethyneamines epoxide hardeners marketed by ACROS (U.S.A.) was carried out by using carbon-13 nuclear magnetic resonance spectroscopy. The products were triethylenetetramine (TETA) and tetraethylenepentamine (TEPA). TETA had four components, the most important one being triethylenetetramine, an ethyleneamine of lineal structure, in a concentration of 60 mol%. Another component had ramified structure, while the other two exhibited recurrent structures of the piperazina type. TEPA had five components with similar structures. The major component was tetraethylenepentamine in an approximate concentration of 55 mol%. These results agree with the composition of similar products marketed by Dow Chemical Company, namely DEH 24 and DEH 26, respectively. (author)

  8. Serial contrast-enhanced magnetic resonance and magnetization transfer in the study of patients with multiple sclerosis; Resonancia magnetica con contraste y transferencia de magnetizacion en el estudio seriado de pacientes con esclerosis multiple

    Energy Technology Data Exchange (ETDEWEB)

    Rovira, A; Alonso, J; Cucurella, G; Nos, C; Tintore, M; Pedraza, S; Rio, J; Montalban, X [Hospital General i Universitari Vall d` Hebron. Barcelona (Spain)

    1998-12-31

    To demonstrate the changes in the magnetization transfer ratio (MTR) of different demyelinating plaques, correlating them with the baseline values in T1-weighted contrast-enhanced magnetic resonance (MR) sequences in order to relate them more closely to the underlying disease. The study was based on 33 demyelinating plaques obtained from six patients clinically diagnosed as having remitting-recurring multiple sclerosis (MS). All the patients underwent two MR studies at a 3 to 5-month interval, including contrast-enhanced T1 and T2- weighted sequences and magnetization transfer images. The latter were used to calculate the MTR for each of the demyelinating plaques included in the study. The statistical analysis of the results obtained revealed statistically significant between initial MTR values and those of subsequent T1-weighted sequences. The MTR demonstrate significant differences between plaques according to contrast-enhanced T1-weigh tes sequences, probably indicating variable degrees of edema, demyelination and tissue destruction. These differences should be taken into account to enable the use of T1-weighted sequences to quantify the lesion load in MS patients. (Author) 35 refs.

  9. Resonancia magnética nuclear en la evaluación de la hipertensión pulmonar

    OpenAIRE

    Caroli, Christian; aman, Bettina; Embón, Mario; Cohen Arazi, Hernán; Perrone, Sergio V.

    2009-01-01

    Se presentan las imágenes de resonancia magnética nuclear de una paciente de 38 años portadora de hipertensión pulmonar idiopática. We present the images of nuclear magnetic resonance of a 38-year-old woman with idiopathic pulmonary hypertension. Apresentam-se as imagens de ressonância magnética nuclear de uma paciente de 38 anos portadora de hipertensão pulmonar idiopatica.

  10. RESONANCIA MAGNÉTICA NUCLEAR DEL PRODUCTO GELIFICADO DE LA REACCIÓN DE CANNIZZARO

    Directory of Open Access Journals (Sweden)

    Lilia Fernández Sánchez

    2015-01-01

    Full Text Available Se presenta n los espectros de resonancia magnética nuclear ( RMN de protón 1 H, de carbón 13 C y bidimensionales , del produc to de una síntesis orgánica verde de óxido - reducción en la r eacción de Cannizzaro. El producto fue reportado como un gel triboquímico y elucidado por análisis de infrarrojo IR , ray os X y micrografía de barrido ( SEM . Los resultados en este artículo confirman su estructura a través de diversas técnicas de RMN y evalúan el contenido de benzoato de sodio y alcohol bencílico en la muestra e mpleada en la espectroscopia a través del examen de los valores de las integrales en la s señales de RMN de 1 H. El resultado del estudio indica que el alcohol bencílico se encuentra en un 33.44% mol (fase dispersa con respecto al cont enido de benzoato de sodio (fase continua . Estos resultado s confirma n la estruct ura de gel que con el tiempo pierde a la fase dispersa el alcohol produciendo un xerogel

  11. Resonancias emocionales de la razón en Kant [Emotional resonances of reason in Kant

    Directory of Open Access Journals (Sweden)

    Nuria Sánchez Madrid

    2016-09-01

    Full Text Available Este artículo se propone calibrar, partiendo del estado actual de la cuestión, las funciones que los sentimientos o emociones ejercen en todo el arco del proyecto crítico, afectando a la concepción del conocimiento y de la acción moral. Para ello, comenzaré analizando el sentido, no sólo retórico, del concepto kantiano de Bedürfnis, planteando sucesivamente la dimensión radical que el sentimiento de placer y displacer posee en el ánimo humano, la necesidad de que la virtud sea ejercida con un corazón alegre, siguiendo la enseñanza de Epicuro, y finalmente la conexión de la belleza con la resonancia afectiva que penetra todo el edificio de la reflexión. En la conclusión extraeré algunas consecuencias que un estudio de las Críticas en clave sentimental puede introducir en la concepción usual de la razón en Kant, ampliando los mecanismos de implantación en el mundo de esta facultad, al reconocer la importancia del sentimiento y la inclinación para la construcción de la autonomía humana.

  12. Tyng Toy, 1949. Resonancias desde los inicios de una pionera desconocida

    Directory of Open Access Journals (Sweden)

    Antonio Juárez Chicote

    2017-04-01

    Full Text Available Anne Griswold Tyng (1920-2011, una de las primeras mujeres que estudia en la GSD de Harvard y coautora con Louis I. Kahn del proyecto de la City Tower –entre otras obras–, desarrolla —y patenta en 1949— el proyecto de un pequeño juguete de madera contrachapada cuyas piezas, organizadas en combinaciones diferentes, pueden ensamblarse formando objetos muy diversos. El proyecto, conocido como Tyng Toy, anticipa el pensamiento investigador de su autora sobre la geometría como “principio de la forma” y condensa las inquietudes de la época y el nuevo sueño de la arquitectura americana tras la segunda guerra mundial. El juguete manifiesta una particular visión del papel del arquitecto como educador social y transformador del medio que le rodea y más allá de la necesidad de reconstrucción que reinaba en los años de posguerra, trasciende los imperativos del momento para hablarnos de otra necesidad paralela y universal: la de reconstruir el universo lúdico, imaginario, educativo y proyectual del ser humano. El pequeño conjunto de cinco piezas de madera, como metáfora simbólica, nos habla de un mundo que es también el nuestro: complejo y ramificado, pedagógico y abierto, y en su planteamiento —sintético e intenso— abarca resonancias universales y profundas.

  13. Síndrome de la cimitarra en resonancia magnética cardiovascular

    Directory of Open Access Journals (Sweden)

    Pedro Abad

    2018-01-01

    Full Text Available El síndrome de la cimitarra es una anomalía parcial del retorno venoso pulmonar de características complejas. Está asociado a múltiples malformaciones cardiovasculares y pulmonares, y representa un diagnóstico diferencial importante en los pacientes con dilatación inexplicada de las cavidades derechas. Se expone el caso de una mujer en la cuarta década de la vida, con un cuadro clínico de dolor torácico, episodios sincopales y deterioro de su clase funcional, que por sus hallazgos en la ecocardiografía fue llevada a resonancia magnética cardíaca que mostró anomalía parcial del retorno venoso pulmonar infracardiaca, hallazgo no visualizado en la ecocardiografía, y que confirmó el diagnóstico específico de síndrome de la cimitarra.

  14. Metamateriales Magnéticos de Anillos Resonantes para Aplicaciones en Imagen Médica por Resonancia Magnética.

    OpenAIRE

    Algarín Guisado, José Miguel

    2017-01-01

    La presente memoria recoge los resultados de una investigación multidisciplinar que combina la reciente disciplina de los metamateriales electromagnéticos con la técnica de obtención de imágenes médicas mediante resonancia magnética. La resonancia magnética (RM) es una de las principales técnicas de obtención de imágenes médicas junto con la tomografía axial computerizada (TAC), la ecografía po...

  15. Diseño de metodologías para la adquisición de resonancia magnética funcional a 1,5t

    OpenAIRE

    Guiu Hernández, Esther

    2009-01-01

    Projecte fet en col.laboració amb Pontificia Universidad Católica de Chile. Escuela de Ingeniería La resonancia magnética funcional (fMRI) es una técnica mediante la cual se puede mapear el cerebro, tanto anatómica como fisiológicamente, sin necesidad de realizar estudios invasivos. A fin de obtener mapas de activación cerebral, el sujeto en estudio debe realizar alguna tarea o estar expuesto a un estímulo externo. Paralelamente se adquieren, mediante resonancia magnética, una gran cantida...

  16. Aplicaciones de los registros de resonancia magnética nuclear (nmrl) en la evaluación de yacimientos

    OpenAIRE

    Landi Torres, Richard Paúl

    2008-01-01

    La extraordinaria tecnología de adquisición de registros o perfilaje de resonancia magnética nuclear (RMN) ha estado en continua evolución durante los últimos 10 años. Las compañías petroleras utilizan las mediciones de RMN en una variedad de aplicaciones cada vez más numerosa; por ejemplo, para caracterizar los fluidos de las formaciones durante la evolución de los yacimientos y determinar la producibilidad de la formación. Hoy en día, las mediciones obtenidas con estas herramien...

  17. Dinámica neuronal del circuito motor: un estudio de resonancia magnética funcional

    OpenAIRE

    Batista García-Ramó, Karla; Rodríguez Rojas, Rafael; Carballo Barreda, Maylén

    2012-01-01

    La modelación de redes neuronales que describan la interacción funcional del circuito cerebral formado por los ganglios basales (GB), el tálamo y la corteza está limitada por las simplificaciones necesarias para reproducir sus propiedades biológicas. Este trabajo tiene como objetivo general modelar el circuito GB-tálamo-corteza para la selección de un programa motor, sobre la base del patrón de conectividad funcional obtenido por imágenes de resonancia magnética nuclear funcional (RMNf). Se i...

  18. Resultados de la resonancia magnética nuclear de cerebro en niños con cefalea

    OpenAIRE

    Gurkas, Esra; Karalok, Zeynep S; Taskm, Birce D; Aydogmus, Ummu; Yilmaz, Cahide; Bayram, Gulsah

    2017-01-01

    Introducción: El objetivo fue describir los resultados de la resonancia magnética nuclear (RMN) en niños con cefalea. Población y métodos: Revisión retrospectiva de las historias clínicas de los pacientes ingresados a los consultorios externos de neurología pediátrica con síntomas de cefalea entre enero de 2013 y diciembre de 2014. Resultados: Se ingresaron 478 pacientes (273 mujeres, 205 varones) con síntomas de cefalea. Los tipos de cefalea fueron migraña en 218 pacientes (45, 6%), cefalea ...

  19. Evaluación cardiaca con tomografía computada y resonancia magnética

    Directory of Open Access Journals (Sweden)

    H. Patricia Bitar, Dra.

    2013-01-01

    Full Text Available La tomografía computada y la resonancia magnética son métodos de imagen distintos, que con los avances tecnológicos han adquirido gran importancia en la evaluación cardiaca en los últimos 10 años. La tomografía computada usa rayos X, por lo que la radiación que emite es la mayor limitante del estudio. Tiene alta resolución espacial, lo que la hace muy útil especialmente en la evaluación de las finas y tortuosas arterias coronarias. La resonancia magnética obtiene las imágenes a partir de aplicación de campos magnéticos y pulsos de radiofrecuencia. Tiene alta resolución temporal y de contraste, por lo que es particularmente útil en la evaluación de función cardiaca, siendo el gold standard, y en la caracterización de tejidos. Permite evaluar anatomía, función, medir flujos, hacer estudios de perfusión y viabilidad miocárdica. El presente artículo tiene por objetivo caracterizar las dos modalidades de imágenes, describir sus ventajas y desventajas y analizar las indicaciones de cada método en la evaluación cardiaca.

  20. Un tal Evo. Resonancias discursivas del primer presidente indígena en América Latina

    Directory of Open Access Journals (Sweden)

    Guido Montali

    2015-06-01

    Full Text Available El presente trabajo busca indagar resonancias en torno a discursos del presidente de la República Plurinacional de Bolivia, Evo Morales Ayma. Decimos resonancias para referirnos al modo en que esos discursos dialogan, no explícitamente, con algunos textos clásicos del pensamiento social latinoamericano que han tratado la cuestión de los pueblos indígenas. Encontraremos referencias desde Mariátegui y Haya de La Torre hasta García Linera. Sostenemos que es posible, a partir de los discursos de Evo Morales, ordenar tiempos históricos que se imbrican en una construcción socio política que busca, en el pasado de exclusión y violencia con los pueblos indígenas y campesinos, las armas para el desmonte de la matriz colonial del Estado y la consolidación de un nuevo Estado plurinacional, apostando a partir de él a un futuro de socialismo comunitario. Uno de los pilares de ese socialismo comunitario es el manejo sustentable de los recursos naturales y el aprovechamiento de los avances tecnológicos, pero bajo un criterio que no responde a la única lógica de la rentabilidad preconizada por el capitalismo.

  1. Estudio de la grasa de teobroma ozonizada usando la Resonancia Magnética

    Directory of Open Access Journals (Sweden)

    Fernández Torres, Irán

    2007-03-01

    Full Text Available Ozonation of theobroma fat at different applied ozone dosages was carried out and peroxide indexes along with antimicrobial activity were determined. The reaction products were identified using Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR. The principal signal intensity values were used for following the reaction course between ozone and theobroma fat. The reaction was followed up to peroxide index values of 544 mmol-equiv/kg. The intensities of olefinic proton signals decreased with the gradual increase in ozone concentration until disappearing completely. The Criegee ozonides obtained at 87.4 mg/g of ozone doses were approximately 3.7 times higher than at the beginning of the reaction. The highest action spectrum of antimicrobial activity was obtained with the higher peroxide index. These results suggest that the 1H NMR spectroscopic technique provides valuable information about of the ozonization grade of theobroma fat which produces an affective antimicrobial activity against Candida albicansSe realizó un estudio de la ozonización de la grasa de teobroma el cual fue seguido a diferentes dosis de ozono y fueron determinados los índices de peróxidos y su actividad antimicrobiana. Los productos de reacción fueron identificado por la espectroscopia de Resonancia Magnética Nuclear Protónica (RMN 1H. Los principales valores de intensidad de las señales fueron usados para el seguimiento de la reacción entre el ozono y la grasa de teobroma. La reacción fue seguida hasta un valor de índice de peróxidos de 1 544 mmolequiv/kg. Las intensidades de las señales de los protones olefínicos desaparecen con un gradual incremento de la concentración de ozono. Los ozónidos de Criegee obtenidos a dosis de ozono de 87,4 mg/g fueron 3,7 veces mayores que los obtenidos al inicio de la reacción. El mayor espectro de acción de la actividad antimicrobiana fue obtenido a mayor índice de peróxidos. Estos resultados sugieren que la t

  2. MRI and MRCP of chronic pancreatitis. 1: technique and methods; La valutazione delle pancreatiti croniche con Risonanza Magnetica e colangiopancreatografia con Risonanza Magnetica. Prima parte: aspetti tecnico-metodologici

    Energy Technology Data Exchange (ETDEWEB)

    Laghi, A.; Pavone, P.; Catalano, C.; Panebianco, V.; Luccichenti, G.; Fabiano, S.; Passariello, R. [Rome Univ. La Sapienza, Rome (Italy). Ist. di Radiologia

    1999-10-01

    Until recently, MR examinations of the pancreas were limited by motion artifacts, vascular pulsatility and poor spatial resolution. Today, new techniques have been developed, which allow to overcome these problems and provide additional information such as selective images of biliary and pancreatic ducts and vascular structures. As a complement to baseline sequences, MR cholangiopancreatography images can be acquired, possibly integrated by functional examination after secretin administration. Finally, contrast-enhanced MR angiography opens new perspectives for vascular studies, particularly for the locoregional staging of pancreatic cancer. [Italian] Lo studio del pancreas con risonanza magnetica e' stato fino a pochi anni fa limitato dagli artefatti da movimento, da pulsatilita' vascolare e dalla ridotta risoluzione spaziale. Recentemente sono state sviluppate nuove tecniche che consentono da un lato di risolvere tali problemi e dall'altro di fornire informazioni aggiuntive, quali immagini selettive delle vie biliari e del dotto pancreatico e delle strutture vascolari. Come completamento all'esame di base si possono ottenere immagini di colangiopancreatografia con RM, eventualmente integrate da prove funzionali, rappresentate dall'iniezione di secretina. Infine, le nuove tecniche di angiografia con RM con mdc, nelle quali si effettua un'acquisizione durante la prima fase di passaggio arterioso o venoso dopo introduzione rapida del mdc a livello di una vena periferica, aprono nuove prospettive per lo studio vascolare, in particolare nella stadiazione loco-regionale dei processi neoplastici.

  3. Tamaño auricular y realce miocárdico en la miocardiopatía hipertrófica mediante resonancia magnética

    OpenAIRE

    Méndez Díaz, María Cristina

    2016-01-01

    [Resumen] Antecedentes y objetivos: La fibrosis miocárdica puede detectarse en la miocardiopatía hipertrófica (MCH) mediante resonancia magnética (RM) con realce tardío de gadolinio. La fibrosis miocárdica y el tamaño de la aurícula izquierda (AI) pueden relacionarse con eventos adversos. Analizamos la relación entre la presencia y extensión del realc...

  4. Entre el Estado y el mercado: resonancias geográficas y sustentabilidad social en Santiago de Chile

    Directory of Open Access Journals (Sweden)

    Francisco Sabatini

    2000-12-01

    Full Text Available Los autores argumentan que los resultados de las políticas urbanas pro-mercado aplicadas en Santiago después de 1973 han estado fuertemente condicionados por la "resonancia geográfica", o impronta espacial, del intervencionismo estatal previo, así como por los "espacios de borde" que el desarrollo urbano está produciendo entre las áreas pobres de la ciudad y los barrios modernos y zonas comerciales que están expandiéndose hoy. Las políticas urbanas no tienen impactos simples o directos en la ciudad, como parece implícito en el enfoque en boga sobre los "impactos territoriales" de la reestructuración capitalista y la globalización, o en la metodología de evaluación de proyectos o políticas que forma parte de las formas privadas y públicas de gestión urbana. Las resonancias geográficas y los espacios de borde pueden, incluso, impulsar resultados paradójicos, algunos de los cuales se analizan en el artículo. La atención que se dé a estas complejidades espaciales puede facilitar una mejor evaluación de las iniciativas de gestión urbana, así como de las peculiaridades de cada ciudadThe authors argue that the results of the post-1973 market-oriented urban policies in Santiago have been strongly conditioned by the "geographical resonance," or spatial imprint, of the earlier state interventionism, as well as by the "border spaces" product of urban development between the city’s poor areas and today’s expanding modern neighborhoods and commercial areas. Urban policies have no simple or direct impact on the city as implied nowadays by the popular approach of "territorial impacts" of capitalist restructuring and globalization, or in the project or policy assessment methodology, that is part of the private and public forms of urban management. Geographical resonances and border spaces could even further paradoxical results, some of which are discussed in the article. The attention paid to these spatial complexities could provide

  5. Magnetic losses and reactance change by the use of metallic conduit in electrical installations; Perdidas magneticas y cambio de reactancia por la tuberia metalica en instalaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Campero Littlewood, Eduardo; Castaneda D, Miguel; Castulo A, Roberto; Bratu Serban, Neagu [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D. F. (Mexico)

    1996-12-31

    In this paper are presented the results obtained in the measurement of magnetic losses in metallic conduits in electric installations. The losses for parasitic currents and by hysteresis were obtained in different conditions of magnetic density, caused by the net current resulting from the sum of all the currents of all the conductors that travel along the conduit. These currents are named differential currents, and the conditions in which they appear in the electric installations are described. The magnetic induction phenomenon that occurs in metallic conduit is briefly described and the basic concepts that describe it. A theoretical-experimental methodology is offered to quantify the energy losses by parasitic currents and by the metal magnetization in these metallic conduits. At the same time, the impact of these differential currents impact in the reactance of the electric installation is quantified. The obtained results for twelve conduits of different diameters and different wall thickness are shown. A comparison analysis is made with the reported results in a previous article, where the losses were estimated by means of the temperature rise measurement of the metallic wall. [Espanol] En este articulo se presentan los resultados obtenidos en la medicion de perdidas magneticas en tuberias conduit (metalicas) en instalaciones electricas. Las perdidas por corrientes parasitas y por histeresis se obtuvieron para diferentes condiciones de densidad magnetica, provocada por la corriente neta resultante de la suma de las corrientes de todos los conductores que viajan por la tuberia. A estas corrientes se les designa corrientes diferenciales y se describen las condiciones en las que estas aparecen en las instalaciones electricas. Se explica brevemente el fenomeno de induccion magnetica que se presenta en las tuberias metalicas y los conceptos basicos que la describen. Se plantea una metodologia teorico-experiemental para cuantificar las perdidas de energia, por

  6. Magnetic losses and reactance change by the use of metallic conduit in electrical installations; Perdidas magneticas y cambio de reactancia por la tuberia metalica en instalaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Campero Littlewood, Eduardo; Castaneda D, Miguel; Castulo A, Roberto; Bratu Serban, Neagu [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D. F. (Mexico)

    1997-12-31

    In this paper are presented the results obtained in the measurement of magnetic losses in metallic conduits in electric installations. The losses for parasitic currents and by hysteresis were obtained in different conditions of magnetic density, caused by the net current resulting from the sum of all the currents of all the conductors that travel along the conduit. These currents are named differential currents, and the conditions in which they appear in the electric installations are described. The magnetic induction phenomenon that occurs in metallic conduit is briefly described and the basic concepts that describe it. A theoretical-experimental methodology is offered to quantify the energy losses by parasitic currents and by the metal magnetization in these metallic conduits. At the same time, the impact of these differential currents impact in the reactance of the electric installation is quantified. The obtained results for twelve conduits of different diameters and different wall thickness are shown. A comparison analysis is made with the reported results in a previous article, where the losses were estimated by means of the temperature rise measurement of the metallic wall. [Espanol] En este articulo se presentan los resultados obtenidos en la medicion de perdidas magneticas en tuberias conduit (metalicas) en instalaciones electricas. Las perdidas por corrientes parasitas y por histeresis se obtuvieron para diferentes condiciones de densidad magnetica, provocada por la corriente neta resultante de la suma de las corrientes de todos los conductores que viajan por la tuberia. A estas corrientes se les designa corrientes diferenciales y se describen las condiciones en las que estas aparecen en las instalaciones electricas. Se explica brevemente el fenomeno de induccion magnetica que se presenta en las tuberias metalicas y los conceptos basicos que la describen. Se plantea una metodologia teorico-experiemental para cuantificar las perdidas de energia, por

  7. Paralelismo clínico e imagenológico por resonancia magnética de los procesos inflamatorios de la médula espinal

    Directory of Open Access Journals (Sweden)

    Rómel Sarmiento Ducóngers

    2017-05-01

    Full Text Available Con el objetivo de identificar las características clínicas y por resonancia magnética de las lesiones inflamatorias de la médula espinal, se realizó un estudio observacional descriptivo transversal, de 56 pacientes, atendidos en los hospitales provinciales de Santiago de Cuba “Dr. Juan Bruno Zayas Alfonso” y “Dr. Saturnino Lora”, durante el periodo comprendido entre enero de 2014 hasta junio de 2015. Las características clínicas de las lesiones inflamatorias de la médula espinal fueron la cuarta década de la vida y el sexo masculino (60,7%, con síntomas predominantes como el dolor, la paresia y la parestesia. Existió predominio de las mielitis compresiva e inflamatoria. Al explorar el grado de concordancia entre la clínica y el informe de la resonancia magnética se obtuvo un índice de Kappa de 0,35. El diagnóstico imagenológico más relevante fue la mielitis compresiva en correspondencia con el diagnóstico clínico, no obstante la investigación permitió determinar que la concordancia entre la clínica y el diagnóstico imagenológico por resonancia magnética en los estudios realizados a estos pacientes en el periodo de estudio fue débil.

  8. Rodríguez Llera, Ramón: Resonancias orientales en la obra de Juan Navarro Baldeweg. La vuelta de Hiroshige

    Directory of Open Access Journals (Sweden)

    Iván I. Méndez Rincón Borrego

    2015-01-01

    Full Text Available A estas alturas, la incansable labor investigadora de Ramón Rodríguez Llera (Santander, 1955 nos sigue sorprendiendo. Después de la publicación de Japón en Occidente. Arqui-tecturas y paisajes del imaginario japonés, del exotismo a la modernidad (2013, obra en la que estudia los intercambios culturales entre la arquitectura occidental y la japonesa desde el despertar del Japón moderno en época Meiji hasta nuestros días, nos descubre Resonancias Orientales en la obra de Juan Navarro Baldeweg.

  9. Análisis longitudinal desde imágenes de resonancia magnética para la detección temprana de la enfermedad del Alzheimer

    OpenAIRE

    Lin, Lin

    2017-01-01

    Alzheimer es una enfermedad neuro-degenerativa, la atrofia de algunas estructuras subcorticales se puede observar en los pacientes de Alzheimer usando neuroimagen. En este proyecto, se estudiará la atrofia de algunas sub-estructuras corticales para obtener bio-marcadores de esa enfermedad usando MRI-T1 y DTI. MRI estructural es sensible a los cambios de materias grises y el hipocampo es un marcador potente de la enfermedad. Se realizará una segmentación longitudinal de imágenes de resonancia ...

  10. La resonancia magnética en el diagnóstico por imagen de la patología glandular salival

    OpenAIRE

    Paz Expósito, J.; Velasco-Ortega, Eugenio; Bullon, Pedro

    1997-01-01

    La resonancia magnética constituye en la actualidad una técnica exploratoria importante en el diagnóstico de la patología médica y quirúrgica. Recientemente, se ha incorporado al campo de la odontoestomatología, contribuyendo de forma decisiva al estudio de la patología de las glándulas salivales, especialmente la glándula parótida, donde puede ser considerada el mejor método de diagnóstico por la imagen. Magnetic resonance is an important exploratory technique in the diagnosis of medical ...

  11. Aplicación de la resonancia magnética funcional en la evaluación prequirúrgica en neurocirugía

    OpenAIRE

    Barrós Loscertales, Alfonso Roberto; Ávila Rivera, César; Parcet Ibars, María Antonia

    2001-01-01

    Setenes Jornades de Foment de la Investigació de la FCHS (Any 2001-2002) La resonancia magnética funcional presenta un gran potencial en la evaluación prequirúrgica de las funciones cognitivas básicas motoras, lingüísticas y mnésicas. Sus resultados se basan en el denominado efecto BOLD (blood oxigenation level dependency) (Ogawa y cols., 1993), que permite visualizar e identificar áreas de incremento metabólico basándonos en el consumo neuronal de oxígeno, in vivo y de forma n...

  12. Uso de la urografía por resonancia magnética en el estudio del aparato urinario frente a la urografía convencional

    OpenAIRE

    Ramos de Campos, M.; Juan Escudero, J.U.; Navalón Verdejo, P.; Ordoño Domínguez, F.; Fabuel Deltoro, M.; Zaragoza Orts, J.

    2007-01-01

    La urografía convencional (UIV) es una exploración fundamental en la valoración del aparato urinario no exenta de morbilidad, como reacciones adversas al contraste (vasovagales y anafilácticas), neurotoxicidad, nefrotoxicidad, así como la irradiación ionizante a la que somete al paciente. Por este motivo se desarrollan técnicas de imagen alternativas como la urografía por resonancia magnética (RM) o urorresonancia. Objetivos: Presentamos un estudio que valora la precisión diagnóstica, especif...

  13. NEUROIMÁGENES EN ENFERMEDAD DE PARKINSON: ROL DE LA RESONANCIA MAGNÉTICA, EL SPECT Y EL PET

    Directory of Open Access Journals (Sweden)

    Dr. Carlos Juri C.

    2016-05-01

    Full Text Available La enfermedad de Parkinson (EP es un trastorno neurodegenerativo, caracterizado por la pérdida progresiva de neuronas monoaminérgicas, en especial dopaminérgicas. En las últimas décadas, se han desarrollado diversos biomarcadores para el estudio de los pacientes con EP. Un grupo de estos biomarcadores son las neuroimágenes, como la resonancia magnética cerebral y las imágenes moleculares, en particular, la tomografía por emisión de positrones (PET y la tomografía por emisión de fotón único (SPECT. Estas técnicas, se han empleado en el diagnóstico temprano de la EP, así como para mejorar el diagnóstico diferencial entre EP y otros parkinsonismos y para monitorizar la progresión de la enfermedad. Con estos fines, se ha utilizado la capacidad de estas técnicas para evaluar la pérdida de la actividad dopaminérgica y de otras vías monoaminérgicas, al igual que la posibilidad de valorar la inflamación y el metabolismo a nivel cerebral. Recientemente, los nuevos criterios para el diagnóstico de la EP reconocen al PET y SPECT como herramientas valiosas en el diagnóstico de esta enfermedad. En este artículo, se analiza la utilidad actual de las técnicas de imagen en pacientes con EP y otros parkinsonismos y sus potenciales aplicaciones futuras.

  14. Dinámica neuronal del circuito motor: un estudio de resonancia magnética funcional

    Directory of Open Access Journals (Sweden)

    Maylen Carballo Barreda

    2012-06-01

    Full Text Available Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} La modelación de redes neuronales que describan la interacción funcional del circuito cerebral formado por los ganglios basales (GB, el tálamo y la corteza está limitada por las simplificaciones necesarias para reproducir sus propiedades biológicas.  Este trabajo tiene como objetivo general modelar el circuito GB-tálamo-corteza para la selección de un programa motor, sobre la base del patrón de conectividad funcional obtenido por imágenes de resonancia magnética nuclear funcional (RMNf.  Se incluyeron cinco poblaciones neuronales y dos circuitos paralelos en competencia. La determinación de los pesos de las conexiones entre las poblaciones neuronales a partir de imágenes de RMNf, contribuyó a una formulación más realista del modelo, permitiendo describir la participación de los GB en la selección de una acción en estado normal y en la enfermedad de Parkinson (EP. La simulación permitió demostrar que ante una pérdida de dopamina superior al 40%, el circuito GB-tálamo-cortical no es capaz de seleccionar entre dos programas motores; y además reflejó la capacidad de adaptación del sistema para compensar el trastorno funcional del circuito motor en la EP

  15. High-resolution magneto stratigraphic of the Eocene-Oligocene boundary in the Umbria-Marche sequence; Stratigrafia magnetica ad alta risoluzione del limite Eocene-Oligocene nella successione Umbro-Marchigiana

    Energy Technology Data Exchange (ETDEWEB)

    Lanci, L.; Lowrie, W.; Montanari, A.

    1998-12-31

    High-resolution magneto stratigraphy across the Eocene-Olicene boundary has been employed in a detailed investigation of the nature of low-amplitude, short-wavelength oceanic magnetic anomalies. [Italiano] La stratigrafia magnetica ad alta risoluzione del limite Eocene-Oligocene ed il magnetismo delle rocce sono stati studiati in dettaglio per verificare la presenza di eventuali inversioni di polarita` brevi (short chrons) e variazioni delle intensita` del campo geomagnetico che possano essere messe in relazione con le anomalie oceaniche a bassa ampiezza e corto periodo.

  16. Identificación experimental de estados de resonancia en la estructura portante de un atomizador. // Experimental identification of resonance states in portable structure of an atomizer.

    Directory of Open Access Journals (Sweden)

    J. Cabrera Gómez

    2001-04-01

    Full Text Available Los atomizadores fabricados por una empresa productora de maquinaria agrícola generan durante su funcionamientoniveles de ruido que resultan molestos tanto para el operario como para el resto de los habitantes de las zonas donde seemplean estos equipos, fundamentalmente en tareas vinculadas a la protección de árboles frutales. Para evaluar la situación,se procedió a realizar mediciones de vibraciones y ruido, las que permitieron cuantificar los niveles de estos parámetros, asícomo identificar las principales fuentes que los generan. También se detectó un posible problema de resonancia estructuralque amplifica considerablemente la vibración producida por el giro del ventilador. Con la finalidad de precisar lascaracterísticas de tal resonancia, se efectuaron nuevas series de mediciones centrando la atención básicamente en el estudiodel comportamiento modal del chasis. El análisis modal experimental realizado sobre la estructura objeto de estudiopermitió comprobar la evidente presencia de estados resonantes. Una vez identificada la causa del problema, se procedió asimular modificaciones de parámetros físicos sobre el modelo modal obtenido, proponiéndose la variante más apropiadapara su solución.Palabras claves: Resonancia mecánica, análisis modal, comportamiento dinámico, medición de vibraciones,frecuencias propias.___________________________________________________________________SummaryThe atomizers manufactured by an agricultural machinery company generate during their operation levels of noise that areannoying as much for the operative as for the rest of the inhabitants of the areas where these equipments are used,fundamentally in tasks linked to the protection of fruit-bearing trees. To evaluate the situation, mensurations of vibrationsand noise were to carried out, wich allowed to quantify the levels of these parameters, as well as to identify the mainsources that generate them. A possible problem of structural

  17. Secuencias rápidas de Eco de Espín en imágen por resonancia magnética

    OpenAIRE

    Santa Marta Pastrana, Cristina

    2011-01-01

    Esta tesis doctoral profundiza en el estudio de las secuencias rápidas turbo espín eco para la adquisición de imagen por resonancia magnética. En particular, se centra en la caracterización de las imágenes obtenidas mediante la combinación de la secuencia turbo espín eco con la adquisición parcial de datos o Fourier parcial. Se propone un método para mejorar la resolución espacial de la imagen sin aumentar el tiempo de exploración respecto de la secuencia original turbo espín eco. Dicha mejor...

  18. Os trigonum tarsi syndrome. Magnetic Resonance features; Sindrome dell'os trigonum tarsi. Ruolo della Risonanza Magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Iovane, A.; Finazzo, M.; Carcione, A.; De Maria, M; Lagalla, R. [Palermo Policlinico Univ. P. Giaccone, Palermo (Italy). Ist. di Radiologia; Midiri, M. [Bari Policlinico Univ., Bari (Italy). Ist. di Radiologia

    2000-02-01

    aspect of the tibia, or hypo mobility to pseudoarthrosis. Forced plantar flexion acquisitions are particularly useful in this condition because can demonstrate the mechanism of injury. [Italian] L'os trigonum tarsi e' un osso accessorio del piede localizzato in sede posterolaterale rispetto al tubercolo esterno dell'astragalo e di solito non da' alcuna sintomatologia. In particolari condizioni, che comportano sollecitazioni o microtraumi ripetuti nel tempo a livello del retropiede puo' essere responsabile di talalgia posteriore realizzando la cosidetta sindrome dell'os trigonum tarsi. Il dolore e' localizzato nella sede preachillea. La diagnosi tuttavia risulta particolarmente complessa i quanto numerose altre forme patologiche si manifestano con la medesima sintomatologia clinica. Con la radiologia tradizionale e' possibile dimostrare la presenza dell'os trigonum e le sue eventuali alterazioni morfo-strutturali. La RM (Risonanza Magnetica) di contro consente non solo di identificare le alterazioni strutturali dell'osso ma anche di riconoscere le lesioni associate dei tessuti molli. Sono stati studiati con RM nove pazienti affetti da sindrome dell'os trigonum tarsi. I pazienti sono stati esaminati nella posizione supina con il piede in posizione indifferente e successivamente bloccato nella flessione plantare. Lo studio e' stato condotto con magnete superconduttivo da 0,5 T impiegando una bobina dedicata per le estremita'. Sono state utilizzate sequenze spin-echo T1, gradient-echo T2* e fast inversion recovery secondo piani di scansione assiali e saggitali. In tutti i pazienti esaminati sono state valutate: sede e morfologia dell'os trigonum; caratteristiche dell'intensita' del segnale delle strutture ossee, cartilaginee e dei tessuti adiacenti; presenza di eventuali lesioni tendinee associate. Non sono state osservate anomalie di sede ne' di forma dell'os trigonum. L

  19. Dobutamine cine magnetic resonance imaging after myocardial infarction; Cine Risonanza Magnetica con dobutamina dopo infarto del miocardio

    Energy Technology Data Exchange (ETDEWEB)

    Giovagnoni, A.; Ligabue, G.; Romagnoli, R. [Modena Univ., Modena (Italy). Scienze Radiologiche, Dipt. di Medicina Interna; Reggio Emilia Univ., Reggio Emilia (Italy). Cattedra di Cardiologia; Rossi, R.; Muia, N.; Modena, M.G. [Modena Univ., Modena (Italy). Dipt. di Scienze Mediche, Oncologiche e Radiologiche; Reggio Emilia Univ. (Italy). Dipt. di Scienze Mediche, Oncologiche e Radiologiche

    1999-12-01

    . [Italian] La cine Risonanza Magnetica (cine RM) con stimolo farmacologico {beta}-adrenergico (stress dobutamina) rappresenta una nuova indagine diagnostica nella valuazione pretrattamento di rivascolarizzazione del paziente con infarto del miocardio. Scopo dello studio e' quello di verificare la validita' diagnostica della cine RM con stimolo farmacologico in confronto con l'ecocardiografia con stimolo farmacologico nella valutazione della vitalita' del miocardio e di proporre un nuovo metodo d'analisi delle immagini di cine RM mediante la sottrazione elettronica d'immagine al fine di ridurre gli elementi soggettivi nella valutazione quantitativa dell'ispessimento parietale. Ventisei pazienti (21 maschi, 5 femmine) con pregresso infarto del miocardio in attesa di intervento di rivascolarizzazione sono stati sottoposti a ecocardiografia con stimolo farmacologico mediante dobutamina e a esame cine RM con dobutamina al fine di verificare la ripresa contrattile dei segmenti giudicati acinetici o ipocinetici all'esame ecocardiografico di base. E' stata infusa dobutamina a dosi crescenti (5, 10, 15{gamma}/kg/min). Per ogni paziente sono stati considerati 16 segmenti del ventricolo sinistro. Nel totale di 416 segmenti miocardici considerati l'analisi qualitativa del movimento parietale con ecocardiografia con dobutamina ha dimostrato 307 segmenti normocinetici, 64 cicatriziali e 45 vitali mentre con la cine Rm sono stati osservati rispettivamente 302 segmenti come normocinetici, 83 cicatriziali e 31 vitali. Tre mesi dopo l'intervento di rivascolarizzazione 15 pazienti sono stati rivalutati per verificare la ripresa contrattile dei segmenti giudicati vitali. L'esame ecocardiografico ha mostrato sensibilita' del 79% e specificita' del 97% mentre per l'analisi qualitativa mediante cine RM la sensibilita' e' stata del 96% e la specificita' dell'86%. Nei pazienti con infarto anterosettale l

  20. Study of the influence of PPO in the compatibility of the system PA6/PC/PPO through nuclear magnetic resonance II - Composition changes in the PA6/PC/PPO system; Estudo da afluencia do PPo na compatibilidade do sistema PA6/PC/PPO atraves de espectrometria de resonancia magnetica nuclear. II - Mudanca na composicao do sistema PA6/PC/PPO

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Dilma Alves; Oliveira, Clara Marize F.; Tavares, Maria Ines Bruno [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas; Menezes, Sonia M.C. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisa

    1997-12-31

    This work aims to study the influence in the quantities of poly(propylene oxide) in the miscibility of the system 6-poly-amide/ poly - carbonate / poly (propylene oxide). NMR was used as chemical instrumental technique for the analysis. Results are presented 15 refs.

  1. Unambiguous assigning of the signals of the nuclear magnetic resonance spectra of {sup 1} H and {sup 13} C of monoterpenes using computational methods; Asignacion inequivoca de las senales del espectro de resonancia magnetica nuclear de {sup 1} H y {sup 13} C de monoterpenos empleando metodos computacionales

    Energy Technology Data Exchange (ETDEWEB)

    Cortes, F.; Cuevas, G.; Tenorio, J.; Rochin, A.L. [Universidad Nacional Autonoma de Mexico, Instituto de Quimica, A.P. 70213, 04510 Mexico D.F. (Mexico)

    2000-07-01

    Ab initio calculations, within the frame of Density Functional Theory were carried out on camphene and {alpha}-pinene. The {sup 1} H and {sup 13} C shifts were estimated according to the recently developed Sum-Over-States Density Functional Perturbation Theory (SOS-DFPT) as implemented in a modified deMon-KS program. The calculations not only reproduced the observed NMR chemical shifts, quantitatively in the case of {sup 1} H nuclei and qualitatively in the case of {sup 13} C nuclei, but also allow assigning unambiguously the signal on these spectra. (Author)

  2. Comparative study between the Spin-echo and 3-D fast imaging techniques in the Knee evaluation with magnetic resonance. Estudio comparativo entre las tecnicas de Spin-Eco ecogradiente 3D, en la evaluacion de la rodilla con resonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Oleaga Zufiria, L.; Ibaez Zubiarrain, A.; Grande Icaran, J.; Vela Martin, A.C.; Cintora Leon, E.; Grau Garcia, M.; Grande Icaran, D. (Hospital Civil de Bilbao. Servicio de Radiodiagnostico. Bilbao (Spain))

    1993-01-01

    We have carried out a retrospective analysis of the results of magnetic resonance (MR) studies in 20 patients, comparing two different sequences. We compared a 2-D spin-echo (SE2D) sequence with a 3-D fast imaging with steady-state precession (FISP3D) sequence in the attempt to compare the reliability of each in the detection of knee injuries. Arthroscopy was employed as a control technique. Our study revealed no statistically significant difference between the two sequences, although the overall sensitivity for the detection of meniscal lesions was slightly greater with the FISP3D sequence; however, the reliability in the detection of ruptures of the posterior cruciate ligament is less with this sequence than with the SE2D sequence. Both sequences showed very low sensitivity in the detection of hyaline cartilage injuries. (Author) 14 refs.

  3. ESTRUCTURA TRIDIMENSIONAL DE LA CITOQUININA N-BENZIL 9 (2 TETRAHIDROPIRANYL ADENINE UTILIZANDO EL MÉTODO DE RESONANCIA MAGNÉTICA NUCLEAR

    Directory of Open Access Journals (Sweden)

    Carlos Rojas

    2004-06-01

    Full Text Available Para comprender la función biológica de las moléculas que conforman los seres vivos es necesario conocer la estructura tridimensional de ellas, pues está comprobado que la función depende más de la distribución espacial que de los mismos componentes. El objetivo del presente trabajo es determinar la estructura de una fitohormona. Uno de los métodos que existen para determinar estas estructuras es la resonancia magnética nuclear pulsada el cual se escogió para este trabajo. Este método se diferencia de la resonancia de onda continua en el hecho de que el campo magnético variable es aplicado en forma de pulsos y su amplitud no puede ser considerada como una perturbación al sistema. La determinación de la estructura exigió la toma de los espectros unidimensionales de H1, C13 y los Distortionless Enhacement by Polarization Transfer (DEPT; este último es una secuencia de pulsos que permite diferenciar entre carbonos unidos a tres, a dos y a un hidrógeno. Con la ayuda del espectro C13 también se pueden distinguir los carbonos que no están enlazados con ningún hidrógeno. Además de éstos, fueron necesarios los siguientes espectros bidimensionales: 1 Heteronuclear Multiple Quantum Correlation (HMQC el cual correlaciona hidrógenos con carbonos que se encuentren enlazados; 2 Heteronuclear Multiple Bond Correlation (HMBC que correlaciona carbonos con hidrógenos que se encuentren a dos o tres enlaces; 3 Correlation Spectroscopy (COSY el cual muestra la correlación entre hidrógenos que se encuentren a dos o tres enlaces; y 4 Nuclear Overhauser Effect Spectroscopy (NOESY el cual correlaciona hidrógenos que distan entre sí menos de 5 Å. A partir de la información obtenida del análisis de estos espectros se dedujo el modelo de la fitohormona que se presenta como resultado del trabajo.

  4. ESTRUCTURA TRIDIMENSIONAL DEL a-CICLOPROPIL- (p-METOXIFENIL-5-PIRIMIDINMETANOL (ANCIMIDOL UTILIZANDO EL MÉTODO DE RESONANCIA MAGNÉTICA NUCLEAR

    Directory of Open Access Journals (Sweden)

    O. Ospina

    2005-12-01

    Full Text Available El Ancimidol, α-ciclopropil-(p-metoxifenil-5-pirimidinmetanol, (C15H16N2O2 es un regulador de crecimiento vegetal sintético, que hace parte del grupo de compuestos heterocíclicos que contienen nitrógeno que inhiben la síntesis de las giberelinas. La estructura de esta molécula se determinó por resonancia magnética nuclear, partiendo de una solución en cloroformo deuterado (CDCl3, utilizando un espectrómetro de 500MHz (campo de 11.7Teslas. Se tomaron espectros unidimensionales RMN 1H, RMN 13C, pruebas DEPT 45, 90 y 135 y espectros bidimensionales HMBC y HMQC. En la estructura obtenida para el Ancimidol, se observaron tres ciclos como son la pirimidina, el metoxifenilo y el ciclopropilo, identi-ficados por la asignación de los átomos de hidrógeno y de carbono y por las relaciones de conectividad dadas por los espectros bidimensionales HMBC y HMQC.

  5. Patogenia, cuadro clínico y diagnóstico imagenológico por resonancia magnética de las hernias discales

    Directory of Open Access Journals (Sweden)

    Yoandra Aroche Lafargue

    2015-03-01

    Full Text Available Las hernias discales constituyen un importante problema de salud que causa ausentismo laboral en personas laboralmente activas, de ahí que el costo generado por esta afección sea motivo de preocupación a escala mundial. La revisión bibliográfica acerca de su patogenia, cuadro clínico y diagnóstico imagenológico resulta de vital importancia para su prevención, diagnóstico y tratamiento oportunos. En el diagnóstico por imágenes, la resonancia magnética ha tenido un mayor impacto en el análisis de las afecciones de la columna vertebral, pues posibilita investigar las características del disco intervertebral. Tiene superioridad diagnóstica respecto a la tomografía axial computarizada y la mielografía, debido a que no utiliza radiaciones ionizantes, en tanto, se considera más sensible y específica para demostrar anomalías, lesiones, así como enfermedades de la columna que no pueden visualizarse o quedar ocultas con los otros métodos

  6. Anatomía Cerebral del mono araña Ateles geoffroyi estudiada utilizando imágenes de resonancia magnética. Primer reporte: estudio comparativo con el cerebro humano Homo Sapiens

    OpenAIRE

    Chico-Ponce de León, Fernando; Platas-Neri, Diana; Muñoz-Delgado, Jairo; Santillán-Doherty, Ana-María; Arenas-Rosas, Rita; Trejo, David; Conde, Rubén; Ojeda-Flores, Rafael; Campos-Romo, Aurelio; Castro-Sierra, Eduardo; Cervantes, Juan José; Braun, Marc

    2010-01-01

    El objetivo del presente estudio cualitativo fue analizar los aspectos morfológicos de la anatomía cerebral interna utilizando imágenes de resonancia magnética (IRM) en dos especies de primates, El mono Araña (A. geoffroyi) y el humano (H. sapiens), tomando como base un estudio comparativo de las estructuras cerebrales de las dos especies, concentrándose primordialmente en el sistema límbico del cerebro del mono araña. Aunque es una especie común en el hemisferio occidental, es interesante pa...

  7. Sistema de medición, control y compensación activa para ciclado de campo magnético en aplicaciones de resonancia magnética nuclear

    OpenAIRE

    Forte, Guillermo Omar

    2013-01-01

    Tesis (DCI)--FCEFN-UNC, 2013 Analiza aspectos de la instrumentación asociada a la técnica de Resonancia Magnética Nuclear (RMN) con Ciclado Rápido de Campo Magnético (FFC, por sus siglas en inglés), los que afectan directamente la calidad de las mediciones realizadas. Se implementó un método para la corrección estática de la dependencia espacial del campo magnético generado por el electroimán principal del sistema, dentro de un volúmen determinado.

  8. Aplicación de Resonancia Magnética Nuclear para la caracterización de fracciones pesadas del petróleo en el proceso de desasfaltado por extracción (DEMEX)

    OpenAIRE

    Avella Moreno, Eliseo

    2011-01-01

    En la literatura, se encontró una gran variedad de criterios para la preparación de muestras y para la adquisición y el procesamiento de los espectros de resonancia magnética nuclear de hidrógeno-1 (RMN 1H) o de carbono-13 (RMN 13C) de petróleos, carbones y sus fracciones. Se definieron 33 nuevos intervalos de integración en los espectros de RMN 1H y 47, en los espectros de RMN 13C. Se unificaron sus límites inferior y superior mediante un tratamiento estadístico realizado con ...

  9. Resonancia de Artículos y Factor de Impacto de Periódicos Brasileños de Contabilidad

    Directory of Open Access Journals (Sweden)

    Iracema Raimunda Brito Neves Aragão

    2014-01-01

    Full Text Available Este estudio buscó identificar qué características de los artículos publicados en periódicos contables brasileños están asociadas a la resonancia en la producción científica. Tiene abordaje teórico-empírico y delineamiento cuantitativo. La estrategia fue el estudio y la colecta utilizó el análisis del contenido de los resultados individuales de búsqueda de cada artículo en el Google Académico. La muestra comprendió 577 artículos publicados entre 2006 y 2011 en los 4 periódicos clasificados en los estratos superiores del Qualis/CAPES 2012: Contabilidade Vista & Revista (Contabilidad Vista & Revisada, Revista Contabilidade & Finanças (Revista Contabilidad & Finanzas, Revista de Contabilidade e Organizações e Revista Universo Contábil (Revista de Contabilidad y Organizaciones y Revista Universo Contable. Fueron efectuados 1.655 registros categorizados en una planilla electrónica, siendo 1.372 citaciones recibidas y 283 artículos no citados. Fue utilizado el coeficiente x2 o chi cuadrado y el análisis de correspondencia, además del cálculo del factor de impacto de los periódicos. Los resultados demostraron media de 2,38 citaciones por artículo y el 49,05% de los artículos no fueron citados. Hay asociación entre periódico, año de publicación e idioma del artículo con citaciones recibidas por vehículo de citación, así como entre idioma del artículo y país de la citación. Los artículos de la RC&F recibieron el 66,33% de las citaciones, siendo el periódico de mayor peso para explicar la variabilidad de los datos. El mayor factor de impacto en 2011 fue el de la RC&F (0,861, seguida de la CVISTA (0,667, RCO (0,458 y UNIVERSO (0,458, con media general de 0,578. Se concluyó que la resonancia de la producción científica analizada puede ser considerada baja, la variabilidad de los datos posee relación con las características de los artículos/periódicos y ha disminuido la distancia del factor de impacto entre

  10. Resonancias tristanescas en la ópera española: Wagnerismo en las óperas de Conrado del Campo

    Directory of Open Access Journals (Sweden)

    Sánchez Sánchez, Víctor

    2010-12-01

    Full Text Available In spite of its importance and impact to Spanish music of the first half of twentieth century, Conrado del Campo’s output, and particularly his operas, have unfairly been forgotten. This article examines Conrado del Campo’s early operas, which reflect a Wagnerian influence and his interest in the development of Spanish opera. Original sources such as the manuscript scores, newspapers reviews and letters written by the composer himself have been consulted and special attention has been paid to the operas El final de Don Álvaro and La tragedia del beso, music dramas heavily infl uenced by Wagner’s Tristan.

    La obra musical de Conrado del Campo, a pesar de su importancia e influencia en la música española de la primera mitad del siglo XX, permanece en un injusto olvido, especialmente su amplio legado operístico. Se realiza en este artículo un estudio y análisis de las primeras óperas de Conrado del Campo, destacando en ellas tanto la asimilación del wagnerismo imperante en esos años como su interés por desarrollar los ideales de la ópera española. Para ello se han acudido a las fuentes originales: los manuscritos de las partituras, comentarios de la prensa y opiniones del propio compositor, con especial detenimiento en las óperas El final de Don Álvaro y La tragedia del beso, dramas líricos en los que resulta evidente la resonancia del Tristán wagneriano.

  11. Evaluación con resonancia magnética de artroplastias totales de rodilla sintomáticas. [MRI evaluation of symptomatic total knee arthroplasties ].

    Directory of Open Access Journals (Sweden)

    Francisco Jose Nally

    2016-08-01

    Full Text Available Introducción  Las artroplastías totales de rodilla (ATR sintomáticas con estudios normales resultan un desafío para el ortopedista. La resonancia magnética nuclear (RMN podría ser una alternativa para arribar al diagnóstico.  Objetivo Evaluar la utilidad de la RMN con secuencias optimizadas en ATR sintomática. Además, realizar un estudio interobservador  para determinar que estructuras anatómicas son evaluables. Material y métodos   Se evaluaron  retrospectivamente 15 casos de ATR operados entre 2007-2012 con dolor periprotésico, con radiografía, centellograma y laboratorio normales, sometidos a una RMN. Se realizó un análisis interobservador utilizando el Coeficiente de correlación intercalase (CCIC y Kappa entre 4 profesionales, un residente de diagnóstico por imágenes y otro de Ortopedia; y 2 médicos con 20 años de experiencia, uno en diagnóstico por imágenes y el otro en rodilla. Resultados  Se hayó líquido articular aumentado en 14 pacientes; sinovitis en 4; un osículo infrapatelar y en ningún caso osteólisis. En 7 casos los ligamentos colaterales pudieron ser evaluados correctamente. Los gemelos, el tejido celular subcutáneo y el aparato extensor  se evaluaron sin dificultad. La RMN encontró causas de dolor en 12 casos. El CCIC mostró concordancia para el ligamento colateral medial, el aparato extensor, gemelos y tejido celular subcutáneo.   Conclusión Nuestro estudio demuestra la utilidad del método en la toma de decisiones.  La concordancia interobservador fue estadísticamente significativa para el análisis del ligamento colateral medial, gemelos y tejido celular subcutáneo.   Nivel de evidencia: III , Estudio diagnóstico

  12. Fracturas por estrés en deportistas: Valor de la resonancia magnética en la predicción de la morbilidad Stress fractures in athletes: Role of magnetic resonance imaging in predicting injury morbidity

    Directory of Open Access Journals (Sweden)

    Javier Maquirriain

    2007-06-01

    Full Text Available La resonancia magnética ha mostrado ser una herramienta eficaz para el diagnóstico precoz de las fracturas por estrés y para la determinación de la gravedad de estas lesiones. El objetivo de este estudio fue determinar la relación entre la gravedad de las fracturas por estrés en deportistas, determinada por resonancia magnética y la morbilidad, estimada por el tiempo de retorno al deporte. Se estudiaron 34 casos de fracturas por estrés, correspondientes a 29 deportistas (12 mujeres; 17 varones; edad 26.3 ± 12.5 años, mediante radiografías y resonancia magnética. Las lesiones fueron clasificadas en cuatro grados según la escala de Arendt. Se determinaron la localización anatómica, el nivel de actividad, el tiempo de diagnóstico y el tiempo de retorno a la actividad deportiva. Los huesos más afectados fueron la tibia (n=12; 35.2%, el escafoides tarsiano (n=5; 14.7% y los metatarsianos (n=4; 11.7. La gravedad de las lesiones fue: grado 1: 14.7%; grado 2: 14.7%; grado 3: 38.2%; grado 4: 32.4%. La correlación entre la gravedad de la lesión y el tiempo de recuperación fue de r=0.66 (p=0.0002. Como conclusión, existe una correlación positiva significativa entre la gravedad de la fractura por estrés, determinada por resonancia magnética, y el tiempo de recuperación. La utilización sistemática de esta clasificación puede ayudar a definir con mayor precisión el cuadro clínico, controlar la rehabilitación y estimar el retorno a la actividad deportiva.Magnetic resonance imaging is a useful tool for stress fractures (SF diagnosis, allowing the estimation of injury severity. The aim of this study was to determine the relation between the severity of SF in athletes determined by magnetic resonance imaging and the morbidity estimated as the time to return to sport. Thirty-four cases of stress fractures, (29 athletes; 12 female, 17 male; age 26.3 ± 12.5, were studied by radiographs and magnetic resonance imaging. Injuries were

  13. LA RESONANCIA MAGNÉTICA Y SUS APLICACIONES EN LA AGROINDUSTRIA, UNA REVISIÓN THE MAGNETIC RESONANCE AND ITS AGRO-INDUSTRY APPLICATIONS, A REVIEW

    Directory of Open Access Journals (Sweden)

    Iván Darío Aristizábal Torres

    2007-12-01

    Full Text Available Las propiedades electromagnéticas que presentan el hidrógeno y otros núcleos que componen los productos agroalimentarios han permitido usar ampliamente la Resonancia Magnética (RM para estudiar, de manera no destructiva, la composición y la estructura interna de estos materiales biológicos en una escala tanto macroscópica como microscópica. En este artículo se explican los principios físicos que sustentan la RM, así como el equipo básico requerido para medir las señales de RM de cualquier muestra biológica y el procedimiento de adquisición de una imagen de RM. También, se hace una revisión de las principales aplicaciones en el sector agroalimentario, destacando principalmente los estudios desarrollados con ésta tecnología para examinar la calidad interna de las frutas y los vegetales. En estos productos, la RM ha sido utilizada para detectar e investigar la evolución de los diferentes factores que determinan la calidad interna luego de la cosecha, durante el almacenamiento y después del procesamiento poscosecha. Los estudios en poscosecha que más se han realizado con ésta tecnología son los relacionados con desordenes de tipo fisiológico que se producen en las frutas durante su almacenamiento y conservación en frío en atmósferas controladas y modificadas. Se espera en un futuro no muy lejano aplicaciones comerciales de sensores de RM en línea, basados en magnetos de bajo campo o con sistemas simplificados de análisis de imágenes, que permitan la determinación rápida y no destructiva de la calidad interna de los productos agroalimentarios.The electromagnetic properties that present hydrogen and other nucleus of agroalimentary products, have allowed widely use of Magnetic Resonance (MR to study the composition and internal structure of these biological materials in a micro and macrocospic scale, in a nondestructive way. In this paper the physical principles, basic equipment to measure the MR signals and the MR

  14. T2-weighted MR imaging of liver lesions: a prospective evaluation comparing turbo spin-echo, breath-hold turbo spin-echo and half-Fourier turbo spin-echo (HASTE) sequences; Estudio de lesiones hepaticas con imagenes de resonancia magnetica potenciadas en T2: evaluacion prospectiva comparando secuencias turbo eco del espin, turbo eco del espin con respiracion sostenida y half-Fourier turbo eco del espin (HASTE)

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.; Villajos, M.; Oses, M. J.; Veintemillas, M.; Rue, M.; Puig, J.; Sentis, M. [Fundacion Parc Tauli. Sabadell (Spain)

    2000-07-01

    To compare turbo spin-echo (TSE), breath-hold TSE and half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences quantitatively and qualitatively in T2-weighted images of liver lesions. The authors evaluated prospectively 89 liver lesions in 73 patients using a 1.0-T magnetic resonance system to compare TSE, breath-hold TSE and HASTE sequences. The quantitative parameters were: lesion-to-liver contrast and lesion-to-liver contrast-to-noise ratio. The qualitative analysis was performed by two observers in consensus who examined four parameters: respiratory artifacts, lesion edge definition, intrahepatic vessel definition and image quality. Repeated measures analysis of variance was utilized to compare the quantitative variables and Friedman's nonparametric test for the qualitative parameters. In quantitative terms, the lesion-to-liver contrast was similar in TSE and breath-hold TSE sequences (2.45{+-}1.44 versus 2.60{+-}1.66), both of which were significantly better than the HASTE sequence (1.12{+-}0.72; p<0.001). The lesion-to-liver contrast-to-noise ratio was significantly higher in the TSE sequence (62.60{+-}46.40 versus 40.22{+-}25.35 versus 50.90{+-}32.10 for TSE, breath-hold TSE and HASTE sequences, respectively; p<0.001). In the qualitative comparisons, the HASTE sequence was significantly better than the TSE and breath-hold TSE sequences (p<0.001) in terms of artifacts and definition of lesion edge and intrahepatic vessels. Image quality was also significantly greater in the HASTE sequence (p<0.001). In quantitative terms, the TSE sequence is better than the breath-hold TSE and HASTE sequences, but there are no movement artifacts in the HASTE sequence, which is also significantly superior to TSE and breath-hold TSE sequences in qualitative terms and, thus, can be employed for T2-weighted images in liver studies. (Author) 17 refs.

  15. Estudio de la conectividad funcional en cerebros de animales de experimentación a partir del análisis de imágenes de resonancia magnética mediante técnicas de clasificación no supervisada

    OpenAIRE

    Moya Payá, Javier

    2012-01-01

    Moya Payá, J. (2013). Estudio de la conectividad funcional en cerebros de animales de experimentación a partir del análisis de imágenes de resonancia magnética mediante técnicas de clasificación no supervisada [Tesis doctoral no publicada]. Universitat Politècnica de València. doi:10.4995/Thesis/10251/18238. Palancia

  16. Resonance absorption of nuclear gamma radiation; Absorption par resonance des rayons gamma; Rezonansnaya absorbtsiya i rasseyanie yadernogo gamma-izlucheniya; Absorcion por resonancia de las radiaciones gamma en los nucleos

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, S S; Perlow, G J [Argonne National Laboratory, Argonne, IL (United States)

    1962-01-15

    electromagnetiques. L'absorption par resonance dans le {sup 57}Fe a ete etudiee en detail. L'intensite de l'absorption, la configuration des raies spectrales et leurs deplacements ont ete observes en fonction de la temperature. La polarisation des rayonnements a ete examinee au cours d'experiences effectuees a l'aide de sources et absorbeurs magnetises. Le spectre hyperfin des rayonnements de resonance a ete analyse avec et sans polarisation. Ces etudes ont conduit a une interpretation de la structure hyperfine en fonction des proprietes des etats nucleaires et de l'interaction hyperfine dans le fer. On a egalement etudie l'effet d'un champ magnetique externe sur la structure hyperfine. L'absorption par resonance dans le {sup 57}Fe a permis d'etudier le rapport entre la chronologie de la desintegration d'un etat nucleaire et le spectre des rayonnements observes. Des observations detaillees ont ete faites sur le spectre des rayonnements de resonance filtres, en fonction du temps, sous toute une serie de conditions. (author) [Spanish] Como ha demostrado Moesbauer, la emision y absorcion sin retrocesos de las radiaciones nucleares proporciona un medio sencillo de estudiar la interaccion entre los nucleos y las radiaciones electromagneticas y, lo que tiene mas importancia aun, un instrumento extremadamente sensible para la investigacion de numerosos problemas fisicos. El nucleo del {sup 57}Fe constituye un ejemplo muy interesante, ya que en el la absorcion por resonancia constituye un detector de gran sensibilidad de los cambios de frecuencia de las radiaciones electromagneticas. Los autores han estudiado detalladamente la absorcion por resonancia en el {sup 57}Fe. Han observado la intensidad de la absorcion, asi como la configuracion y el desplazamiento de las lineas espectrales en funcion de la temperatura. Examinaron la polarizacion de las radiaciones mediante experimentos realizados con ayuda de fuentes magnetizadas y de absorbentes, y analizaron el espectro hiperfino de la

  17. Resonances and Tides in Natural Satellites Systems. (Breton Title: Ressonâncias e Marés em Sistemas de Satélites Naturais.) Resonancias y Mareas en Sistemas de Satélites Naturales

    Science.gov (United States)

    Callegari, Nelson, Jr.

    2006-12-01

    sica, e não a descrição detalhada dos conceitos aqui discutidos. Describimos en este trabajo algunos aspectos de la dinámica de resonancias de movimientos promedio. Será dado un énfasis mayor al caso de las resonancias entre satélites regulares de los planetas gigantes, aunque también son discutidos brevemente algunos aspectos de la física de resonancias en sistemas panetarios extrasolares. La importancia del estudio de las resonancias en sistemas de satélites es discutida más detalladamente através de ejemplos, mostrando cómo ciertas resonancias y los efectos de disipación por mareas pueden ser la clave de parte de la explicación de algunos fenómenos aún no comprendidos en el Sistema Solar. Entre varios ejemplos se destacan el problema de la superficie remodelada del satélite Enceladus, la existencia de volcanes activos en Io y la posible existencia de un océano subterráneo en Europa. Este trabajo tiene como objetivo la divulgación de algunos tópicos en Mecánica Celeste y Planetología para un público universitario de ciencias exactas, en particular Astronomía y Física, y no la descripción detallada de los conceptos aquí discutidos.

  18. Valor de la resonancia magnética de imágenes en pacientes con enfermedad cerebrovascular isquémica Evaluation of the magnetic resonance imaging in patient with ischemic cerebrovascular disease

    Directory of Open Access Journals (Sweden)

    Laura María Pons Porrata

    2009-04-01

    Full Text Available La resonancia magnética de imágenes permite investigar aspectos morfológicos y funcionales del cerebro, lo cual es sumamente útil para diagnosticar enfermedades neurológicas, incluidas las cerebrovasculares y, por supuesto, la isquemia cerebral en las primeras horas de ocurrida, de modo que facilita seguir la evolución del ictus, reducir la zona de necrosis y garantizar una mejor calidad de vida de los pacientes. A diferencia de la tomografía y la angiografía no utiliza radiaciones ionizantes. En este artículo se concluye, entre otras inferencias, que su elevada sensibilidad supera el número de confirmaciones obtenidas a través de la tomografía axial computarizada.Magnetic resonance imaging allows to investigate morphological and functional aspects of the brain, something extremely useful to diagnose neurological diseases, including the cerebrovascular diseases and, of course, the cerebral ischemia in the first hours of its ocurrence, so it facilitates to follow the clinical course of ictus, to reduce the necrosis area and to guarantee a better life quality of patients. Contrary to tomography and angiography it doesn't use ionizing radiations. In this article it is concluded, among other things, that its high sensibility overcomes the number of confirmations obtained through computarized axial tomography.

  19. CE-Magnetic Resonance mammography for the evaluation of the contralateral breast in patients with diagnosed breast cancer; Ruolo della Risonanza Magnetica con Gd-BOPTA nella valutazione della mammella controlaterale in pazienti con tumore recentemente diagnosticato

    Energy Technology Data Exchange (ETDEWEB)

    Pediconi, Federica; Venditti, Fiammetta; Padula, Simona; Roselli, Antonella; Moriconi, Enrica; Catalano, Carlo; Passariello, Roberto [La Sapienza Univ., Roma (Italy). Dipartimento di scienze radiologiche; Giacomelli, Laura [La Sapienza Univ., Roma (Italy). Dipartimento di scienze chirurgiche

    2005-07-15

    Purpose. To evaluate the role of contrast-enhanced Magnetic Resonance Mammography (MRM) in the evaluation of the contralateral breast in patients with recently diagnosed breast cancer. Materials and methods. Fifty patients with proved unilateral breast cancer, with a negative contralateral breast at physical examination, ultrasound and mammography, were studied with a 1.5 T magnet (Siemens, Vision Plus, Germany). A bilateral breast surface coil was used. Dynamic 3D Flash T1-weighted sequences were acquired in the axial plane before and 0, 2, 4, 6 and 8 minutes after the administration of 0.1 mmol/kg of Gd-BOPTA at a flow rate of 2 ml/s followed by 10 ml of saline. The level of suspicion was reported on a scale from 0 to 5 following the BI-RADS classification, based on lesion morphology and kinetic features. The results were compared with the histological findings after biopsy or surgery. Results. Fourteen out of 50 patients (28%) had contralateral lesions identified on MRM. Biopsy was performed in four of them for suspicious lesions (BI-RADS 4) while 10 patients underwent surgery because of highly suggestive malignant lesions (BI-RADS 5). Histology diagnosed three fibroadenomas, 5 ductal carcinoma in situ, 2 lobular carcinomas in situ, 3 invasive ductal carcinomas and 1 invasive lobular carcinoma. Contrast enhanced MRM yielded no false negative and three false positives. Conclusions. Our results demonstrate a very good accuracy of Magnetic Resonance Mammography in the detection of synchronous contralateral cancer in patients with newly diagnosed breast cancer. Therefore, contrast-enhanced MRM could be introduced to screen patients with proven breast cancer before they under-go surgery. [Italian] Scopo. Definire il ruolo della Risonanza Magnetica nella valutazione della mammella contro laterale in pazienti con tumore della mammella recentemente diagnosticato. Materiale e metodi. Cinquanta pazienti con tumore monolaterale della mammella e mammella controlaterale

  20. Caracterización clínica e imagenológica de la hernia discal mediante resonancia magnética Clinical and imaging characterization of discal hernia by means of magnetic resonance

    Directory of Open Access Journals (Sweden)

    Yoandra Aroche Lafargue

    2012-08-01

    Full Text Available Se realizó un estudio descriptivo y transversal de 635 pacientes con hernia discal atendidos en el Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba, desde diciembre del 2009 hasta igual mes del 2010, para determinar las características clínicas e imagenológicas de esta afección mediante resonancia magnética. En la casuística primaron el grupo etario de 30 a 49 años, el sexo masculino, la obesidad como principal factor de riesgo en las mujeres y la carga física excesiva en los hombres, así como el dolor, la localización lumbar y las hernias posteriores centrolaterales y laterales derechas. Se encontró que las protrusiones focales y difusas resultaron ser las más comunes, asociadas a edema óseo en las placas terminales, que la compresión medular y las mielopatías secundarias fueron provocadas por protrusiones focales cervicales y que la estenosis del canal se presentó mayoritariamente en el segmento lumbar.A descriptive and cross-sectional study of 635 patients with discal hernia assisted in "Dr. Juan Bruno Zayas Alfonso" Teaching General Hospital in Santiago de Cuba was carried out from December, 2009 to the same month of 2010, to determine the clinical and imaging characteristics of this disorder by means of magnetic resonance. The age group from 30 to 49 years, male sex, obesity as the main risk factor in the women and the excessive physical load in the men prevailed in the case material, as well as the pain, the lumbar localization and the right posterior centro-lateral and lateral hernias. It was found that the focal and diffuse protrusions turned out to be more common, associated with bony edema in the terminal plates, that the medullary compression and the secondary myelopathies were caused by cervical focal protrusions and the stenosis of the channel was mainly presented in the lumbar segment.

  1. Estudio de la capa de fibras nerviosas de la retina mediante tomografía de coherencia óptica y polarimetría láser en pacientes con esclerosis múltiple: correlación con la función visual y los hallazgos de la resonancia magnética

    OpenAIRE

    Abalo Lojo, José Manuel

    2012-01-01

    Introducción: La tomografía de coherencia óptica (OCT) y la polarimetría láser (GDx) son técnicas exploratorias de la capa de fibras nerviosas de la retina (CFNR). Hipótesis: En los pacientes con EM, el posible daño estructural de la CFNR y su correspondiente alteración de la función visual sería un reflejo del daño del SNC y por lo tanto se correlacionaría con las alteraciones de la resonancia magnética (RM) y la discapacidad Material y métodos: El estudio se ha realizado con 96 paci...

  2. Electromagnetic resonance waves. Resonancias de ondas electromagneticas

    Energy Technology Data Exchange (ETDEWEB)

    Villaba, J.M.; Manjon, F.J.; Guirao, A.; Andres, M.V.

    1994-01-01

    We describe in this paper a set of experiments designed to make qualitative and quantitative measurements on electromagnetic resonances of several simple systems. The experiments are designed for the undergraduate laboratory of Electricity and Magnetism in Physics. These experiments can help the students understanding the concept of resonance, which appears in different fields of Physics. (Author) 8 refs.

  3. Cholangiopancreatography for magnetic resonance (CPRM), using T2 - TSE technique and reconstructions 3D - Experience with 38 patients

    International Nuclear Information System (INIS)

    Esguerra Espinosa, Monica

    1997-01-01

    Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive diagnostic method for the study of the biliary system that does not require contrast media or exposure to ionising radiation. Thirty-eight patients were studied; five apparently healthy ones only with MRCP; and 33 with possible biliary tract pathology, most of which had both endoscopes retrograde cholangiopancreatogaphy (ERCP) and MRCP: All MRCP's were performed with a 3D - TSE sequence with T2 - weighting, using coronal thin contiguous slices and reconstructions with maximal intensity projections (MIP) on different planes. MRCP allows an excellent anatomic depiction of the biliary tree and pancreatic duct

  4. Late gadolinium enhancement by magnetic resonance explains adverse cardiac events in individuals with ventricular arrhythmia; Realce tardío con gadolinio por resonancia magnética explica eventos cardíacos adversos en individuos con arritmia ventricular

    Energy Technology Data Exchange (ETDEWEB)

    Courtis, J.; Vasallo, J.; Arabia, L. [Departamento de Imágenes, Cardiología Intervencionista y Electrofisiología Instituto Oulton, Córdoba (Argentina); Dimitroff, M.; Gonzalez, A. [Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Códoba (Argentina); Tibaldi, M., E-mail: javiercourtis@oulton.com.ar [Técnicas no Invasivas y Arritmias, Instituto Modelo de Cardiología, Córdoba (Argentina)

    2012-07-01

    Objective: To determine whether the presence of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) predict adverse cardiac events in patients with ventricular arrhythmia. Methods: We selected 74 consecutive patients with symptomatic ventricular arrhythmia (premature ventricular contractions and ventricular tachycardia) and left ventricular ejection fraction (LVEF) >55% sent to CMR for evaluation of structural heart disease previously undetected by other complementary methods. LGE, systolic function and volumes of both ventricles were analyzed. At follow-up was assessed a combined end point: hospitalization for ventricular arrhythmia, appropriate implantable cardioverter-defibrillator therapy and cardiac death. Results: During a median follow up of 575 days (interquartile range 24-1120 days) and by analyzing the population according to the presence (n=9, 12%) or not (n=65, 88%) LGE was observed that the group with positive Gd had lower LVEF (58% vs. 66% respectively, p=0.01) and larger volumes (EDV: 185 ml vs. 123 ml respectively, p=0.01 and ESV: 81 ml vs. 42 ml respectively, p=0.01) than the other group. Two (22%) patients in the LGE + group vs. one (4%) of those without LGE showed the combined endpoint (p=0.01) and when performing a logistic regression analysis it was found that the LGE is a predictor of adverse cardiac events analyzed (p=0.029). Conclusions: In this consecutive series of patients with ventricular arrhythmia we demonstrate a strong association between myocardial LGE and adverse cardiac events; this supports the hypothesis that myocardial fibrosis is an important arrhythmogenic substrate. In addition, almost all individuals without LGE were free of events during follow-up suggesting that it is possible to identify through the CMR low-risk individuals who can be treated conservatively. (authors) [Spanish] Objetivo: determinar si la presencia de realce tardío con gadolinio (RTG) por resonancia magnética cardiovascular (RMC

  5. Nuclear magnetic resonance spectroscopy in biomedicine. Course organized by the Istituto Superiore di Sanita`. Marciana Marina (Isola d`Elba), September 18-23, 1995; Spettroscopia di risonanza magnetica nucleare in biomedicina. Corso organizzato dall`Istituto Superiore di Sanita`. Marciana Marina (Isola d`Elba), 18-23 settembre 1995

    Energy Technology Data Exchange (ETDEWEB)

    Luciani, A M; Rosi, A [ed.; Istituto Superiore di Sanita` , Rome (Italy). Lab. di Fisica

    1997-12-01

    Nuclear magnetic resonance is a powerful technique that can be used in a wide range of applications, such as the structural characterization of high molecular weight molecules, conformational studies on enzymes in solution, enzyme-substrate or DNA-protein interactions, monitoring of cell metabolism in vivo, and for diagnostic purposes, employing spectroscopic and imaging techniques. This course was organized in order to introduce the participants to the fundamentals of NMR spectroscopy, and offer practical advice on performing NMR experiments on cell systems, cell and tissue extracts and animal models. The main implications regarding human experiments were also discussed. Finally the quantification of information and the interpretation of data were considered with regard to the main nuclei observed. [Italiano] La risonanza magnetica nucleare e` una delle tecniche spettroscopiche che meglio risponde all`ampio spettro di condizioni imposto dalla ricerca in biofisica e biomedicina. Il campo applicativo di questa tecnica copre un intervallo molto ampio che va dalla caratterizzazione di strutture di macromolecole con elevato peso moleculare, a studi di tipo conformazionale su enzimi in soluzione e sull`interazione enzima-substrato o DNA-proteine, fino al monitoraggio in vivo del metabolosmi cellulare e alla diagnostica medica con spettroscopia ed imaging. Il corso e` stato articolato in modo da presentare ai partecipanti nozioni di base della spettroscopia RMN, aspetti pratici della realizzazione di esperimenti di spettroscopia in sistemi cellulari, in estratti cellulari e tissutali e in animali da esperimento, nonche` le principali considerazioni relative agli esperimenti nell`uomo. Sono state affrontate tematiche relative alla quantificazione dell`informazione e all`interpretazione dei dati in relazione ai principali nuclei osservati.

  6. Estenose degenerativa do canal lombar: correlação entre o índice de Oswestry e imagem de ressonância magnética Estenosis degenerativa del canal lumbar: correlación entre el índice de Oswestry y la resonancia magnética Degenerative lumbar spinal stenosis: correlation between Oswestry index and magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Wagner Pasqualini

    2012-12-01

    Full Text Available OBJETIVOS: Verificar a relação entre o grau de estenose do canal lombar (ECL com a ressonância nuclear magnética (RM e a gravidade da disfunção, de acordo com o Índice de Oswestry em pacientes com ECL e em controles. MÉTODOS: Vinte e três pacientes com diagnóstico de ECL foram comparados com grupo controle de 17 voluntários. Todos foram submetidos a RM e responderam ao questionário de Oswestry. A análise estatística utilizou o teste exato de Fisher, de Mann-Whitney e de Spearman. RESULTADOS: Dor lombar foi a queixa mais frequente em ambos os grupos. O índice de Oswestry mostrou disfunção, em média, em 45,69% no grupo ECL e 11,60% no controle. A RM revelou que a área longitudinal do saco dural, o diâmetro do canal e os recessos laterais e forames estavam igualmente alterados em ambos os grupos. CONCLUSÕES: Não houve correlação entre o grau de estenose e o índice de Oswestry nos dois grupos.OBJETIVOS: Investigar la relación entre el grado de estenosis de canal lumbar (ECL con imágenes de resonancia magnética (RM y la gravedad de la disfunción de acuerdo con el Índice de Oswestry en pacientes con ECL y controles. MÉTODOS: Veintitrés pacientes con un diagnóstico de ECL se compararon con un grupo control de 17 voluntarios. Todos los pacientes fueron sometidos a resonancia magnética y completaron el cuestionario Oswestry. Para el análisis estadístico se utilizó la prueba exacta de Fisher, Mann-Whitney y de Spearman. RESULTADOS: El dolor de espalda es la queja más frecuente en ambos grupos. El índice de disfunción de Oswestry mostró en promedio 45,69% para el grupo ECL y 11,60% para el grupo control. La RM demostró que el área longitudinal del saco dural, el diámetro del canal y de los agujeros y las cavidades laterales se han cambiado de manera similar en ambos grupos. CONCLUSIONES: No se encontró correlación entre el grado de estenosis y el índice de Oswestry en ambos grupos.OBJECTIVES: To verify the

  7. Caracterización cualitativa de poliaminas libres en endurecedores de resinas epoxídicas del tipo etilenaminas por espectroscopia de resonancia magnética nuclear Qualitative characterization of free polyamines in ethyleneamines epoxide hardeners by nuclear magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Filiberto González Garcia

    2008-03-01

    Full Text Available La caracterización cualitativa de dos agentes de curado comerciales de resinas epoxídicas del tipo etilenaminas comercializados por la ACROS (U.S.A. fue realizada usando la espectroscopia de resonancia magnética nuclear de carbono-13. Los productos comerciales corresponden a la trietilentetramina (TETA y a la tetraetilenpentamina (TEPA. El producto TETA presentó cuatro compuestos diferentes. El compuesto mayoritario correspondió a la trietilentetramina en una concentración de 60% molar que corresponde a una etilenamina de estructura linear. Los otros tres compuestos, uno de ellos mostró estructura ramificada, y los otros dos compuestos presentaron estructuras cíclicas del tipo piperazina. El producto TEPA mostró cinco compuestos con estructuras semejantes a las encontradas en el producto TETA. El compuesto mayoritario correspondió a la tetraetilenpentamina en una concentración aproximada de 55% molar. Los resultados encontrados en este trabajo están de acuerdo con la composición cualitativa de los productos semejantes comercializados por la Compañía Química Dow, productos DEH 24 y DEH 26, respectivamente.The qualitative characterization of two commercial ethyneamines epoxide hardeners marketed by ACROS (U.S.A. was carried out by using carbon-13 nuclear magnetic resonance spectroscopy. The products were triethylenetetramine (TETA and tetraethylenepentamine (TEPA. TETA had four components, the most importante one being triethylenetetramine, an ethyleneamine of lineal structure, in a concentration of 60 mol%. Another component had ramified structure, while the other two exhibited recurrent structures of the piperazina type. TEPA had five components with similar structures. The major component was tetraethylenepentamine in an approximate concentration of 55 mol%. These results agree with the composition of similar products marketed by Dow Chemical Company, namely DEH 24 and DEH 26, respectively.

  8. Analysis of the sensitivity of the impact resonance frequency test as a tool to determine the elastic properties of bituminous materials; Análisis de la sensibilidad del ensayo de resonancia por impacto como herramienta para determinar las propiedades elásticas de materiales bituminosos.

    Energy Technology Data Exchange (ETDEWEB)

    Tauste, R.; Moreno-Navarro, F.; Gallego, R.; Rubio-Gámez, M.C.

    2017-07-01

    The modulus value of bituminous materials is a key factor in the design of road pavements and the estimation of their life service. This parameter can be measured in laboratory but, unfortunately, this requires the deterioration of the pavement so as the consumption of time and resources. Therefore, this study analyses the feasibility of using impact resonance frequency tests as an alternative to traditional methods for determining the dynamic modulus of bituminous mixtures. The sensitivity of this technique has been studied by analyzing its repeatability and reproducibility, studying the variations in the values measured by modifying the dimensions of the specimens, test temperatures and types of mixture tested. In addition, this non-destructive technique has been compared with other traditional tests used to determine the elastic properties of bituminous materials. The results show that this test could be an interesting tool to characterize the properties and damage state of asphalt layers. [Spanish] El valor de módulo de los materiales bituminosos es un factor clave en el diseño de pavimentos y la estimación de su vida de servicio. Este parámetro puede ser medido en laboratorio pero, desafortunadamente, esto requiere deteriorar el pavimento así como el consumo de tiempo y recursos. Por ello, este estudio analiza la viabilidad de usar el ensayo de frecuencia de resonancia mediante impacto como alternativa a los métodos tradicionales para determinar el módulo dinámico de mezclas bituminosas. La sensibilidad de esta técnica se ha estudiado analizando su repetibilidad y reproducibilidad, estudiando variaciones en los valores medidos al modificar dimensiones de probetas, temperaturas y tipos de mezcla ensayados. Además, esta técnica no destructiva se ha comparado con otros ensayos tradicionales empleados para determinar propiedades elásticas de materiales bituminosos. Los resultados muestran este ensayo como una herramienta interesante para caracterizar

  9. Szilard-Chalmers Processes in Ammonium Dihydrogen Phosphate as Studied by Electrophoresis and Electron Spin Resonance Techniques; Processus Szilard-Chalmers dans le Phosphate d'Ammonium Biacide Etudies par ELectro- Phorese et Resonance de Spin Electronique; 0418 0417 0423 0427 0414 ; Procesos Szilard-Chalmers en el Fosfato Monoamonico Estudiados por Electroforesis y Resonancia del Spin Electronico

    Energy Technology Data Exchange (ETDEWEB)

    Fenger, J.; Nielsen, S. O. [Danish AEC Research Establishment, Riso (Denmark)

    1965-04-15

    identificar y caracterizar estos defectos por determinacion de la resonancia del spin electronico y exponen los resultados de un estudio por electroforesis y por resonancia del spin electronico efectuado con monocristales de fosiato monoamonico, despues de irradiarlos con neutrones en una columna termica a temperaturas comprendidas entre -196 Degree-Sign C y 40 Degree-Sign C. Se han registrado los espectros de resonancia del spin electronico en monocristales de ND{sub 4}D{sub 2}PO{sub 4} irradiados. Se han observado cuatro sistemas de lineas. Tres de ellos, que constituyen la parte exterior del espectro, se reducen a dobletes en ciertas orientaciones del cristal, lo que indica un acoplamiento hiperfino del {sup 31}P. No se han hallado indicios de acoplamiento del {sup 32}P. La parte central del espectro puede tambien producirse por irradiacion gamma pura. Se ha comprobado que uno de los sistemas de lfneas de la parte exterior del espectro proviene de los atomos calientes de retroceso resultantes del proceso {sup 14}N(n, p) {sup 14}C, y se ha atribuido a radicales fosfito que se hallan orientados de ocho maneras distintas en la red cristalina. Se exponen brevemente los resultados de la regeneracion por recocido termico y por irradiacion, estudiada por electroforesis. El resultado mas notable es que el ND{sub 4}D{sub 2}PO{sub 4} y el NH{sub 4}H{sub 2}PO{sub 4}, sometidos a irradiacion neutronica a 4 Degree-Sign C, -78 Degree-Sign C y -196 Degree-Sign C, difieren en su retencion, que para las tres temperaturas mencionadas es aproximadamente 50% mayor en compuesto deuterado. (author) [Russian] Neposredstvenno o defektah, obrazujushhihsja v kristallicheskih fosfatah za schet gorjachih atomov otdachi v rezul'tate jadernoj reakcii fosfor-31 (n, {gamma}) fosfor -32, imeetsja malo informacii, hotja imeetsja podrobnaja informacija o sostojanii fosfora-32 posle rastvorenija kristallov, obluchennyh nejtronami. Predprinimaja popytku ustanovit' i dat' harakteristiku jetim defektam s

  10. Measurement of resonance parameters of cross-sections affecting fast-neutron propagation in various media; Mesure des parametres de resonance de sections efficaces lies a la propagation des neutrons dans differents milieux; Izmerenie parametrov rezonansnoj struktury sechenij, vliyayushchikh na rasprostranenie bystrykh nejtronov v sredakh; Medicion de los parametros de resonancia de las secciones eficaces que afectan a la propagacion de los neutrones rapidos en distintos medios

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaev, M N; Filippov, V V; Bondarenko, I I [Academy of Sciences, Moscow, Union of Soviet Socialist Republics (Russian Federation)

    1962-03-15

    une grande influence sur la propagation des neutrons dans la matiere va de plusieurs dizaines de keV, pour les noyaux lourds, a plusieurs dizaines de MeV pour les noyaux intermediaires. Pour evaluer les effets de resonance lors du calcul des parametres de groupes, il faut connaitre non seulement les sections efficaces d'interaction moyenne entre les neutrons et la matiere, mais aussi certaines valeurs telles que (1/{Sigma}{sub t}), (1/{Sigma}{sub t}{sup 2}), etc. - les signes () signifiant que l'on prend la moyenne du groupe d'energie. Actuellement, les donnees dont on dispose sur les parametres de resonance dans le domaine des neutrons rapides ne sont pas suffisantes pour calculer ces moyennes avec la precision necessaire. A cet egard il est interessant de mesurer directement les moyennes (1/{Sigma}{sub t}), (1/{Sigma}{sub t}{sup 2}) et d'autres caracteristique s analogues. Les auteurs decrivent les resultats obtenus par la mesure d'un certain nombre de parametres tels que ({Sigma}{sub t}), ({Sigma}{sub t}{sup 2}), (1/{Sigma}{sub t}), (1/{Sigma}{sub t}{sup 2}), (1/{Sigma}{sub t}{sup 3}), etc. qui caracterisent la structure de la section efficace de divers noyaux intermediaires dans une gamme d'energie allant de 300 keV a 3 MeV. On est parvenu a mesurer ces moyennes par une analyse des courbes de transmission obtenues grace a une bonne configuration geometrique pour des taux de transmission allant jusqu'a {approx}10{sup -2}. Les donnee recueillies montrent que les effets de resonance influent fortement sur les caracteristiques de diffusion de la matiere. (author) [Spanish] En el planteo de los sistemas de constantes que intervienen en la teoria de los multigrupos para el calculo de reactores de neutrones rapidos y de neutrones intermedios, es preciso considerar en muchos casos los efectos de autoblindaje relacionados con la estructura resonante de las secciones eficaces. El intervalo energetico dentro del cual la resonancia ejerce una influencia decisiva sobre la

  11. Solitary pulmonary nodule: radiologic features and diagnostic approach; Nodulo pulmonar solitario: caracteristicas radiologicas y abordaje diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Cambronero, Luis Enrique

    2012-07-01

    A literature review is conducted on the solitary pulmonary nodule, to determine the diagnostic methods and specific characteristics. The diagnostic methods used have been: chest radiography, computed tomography, positron emission tomography and magnetic resonance imaging. The radiological features are defined: location, size, definition of contours or edges (margins), densitometric and attenuation characteristics, cavitation, air bronchogram, growth, doubling time, satellite nodules, nutrient vessels [Spanish] Una revision bibliografica es realizada sobre el nodulo pulmonar solitario, para determinar los metodos de diagnostico y caracteristicas especificas. Los metodos de diagnostico utilizados han sido: la radiografia de torax, tomografia computarizada, tomografia por emision de positrones y resonancia magnetica. Las caracteristicas radiologicas son definidas: localizacion, tamano, definicion de los bordes o contornos (margenes), caracteristicas densitometricas y de atenuacion, cavitacion, broncograma aereo, crecimiento, tiempo de duplicacion, nodulos satelite, vasos nutrientes.

  12. Resonancia magnética nuclear en el postoperatorio de discectomía lumbar en pacientes asintomáticos y con síndrome de cirugía lumbar fallida Ressonância nuclear magnética no pós-operatório da discectomia lombar em pacientes assintomáticos e com síndrome de cirurgia lombar falida Nuclear magnetic resonance in postoperative lumbar discectomy in asymptomatic patients and with failed back surgery syndrome

    Directory of Open Access Journals (Sweden)

    Armando Alpizar-Aguirre

    2010-03-01

    Full Text Available OBJETIVO: analizar los cambios posquirúrgicos en pacientes sometidos a discectomía lumbar, tanto en pacientes cuya evolución ha sido satisfactoria, como en aquellos con "Síndrome de Cirugía Lumbar Fallida", enfatizando el justo valor que la resonancia magnética nuclear tiene. MÉTODOS: el universo de trabajo está constituido por dos grupos: Grupo I, cinco pacientes con evolución satisfactoria, asintomáticos; y Grupo II con diez pacientes con resultados considerados no satisfactorios y/o Síndrome Fallido Lumbar. Se analizaron los resultados obtenidos en la imagen de resonancia magnética nuclear, emitiendo un diagnóstico con evaluación externa sin conocimiento del estado clínico de los pacientes. También se realizó la correlación con el estado clínico en ambos los grupos. RESULTADOS: las manifestaciones clínicas preoperatorias tuvieron una distribución muy similar. En ninguno de los dos grupos se reportaron complicaciones transoperatórias. En todos se estudió por histopatología y se reportó disco degenerado o hialinizado. En el Grupo I, no se encontró imagen de alguna anomalía a pesar de su estado clínico. En todos los pacientes se encontraron datos de fibrosis posquirúrgica; en cuatro casos, disco residual con compresión radicular en los cinco pacientes. En el Grupo II, sólo en ocho pacientes, la resonancia magnética nuclear demostró algún hallazgo anormal. Los hallazgos anormales fueron: fibrosis posquirúrgica en cinco casos (50%, disco residual en tres casos (30% y datos de compresión radicular en seis de los casos (60%. CONCLUSIÓN: no hay congruencia entre los hallazgos de resonancia magnética nuclear y la clínica, en pacientes postoperados de discectomía lumbar con evolución satisfactoria, hasta el momento, asintomáticos. La resonancia magnética nuclear no es confiable en estos pacientes.OBJETIVO: analisar as mudanças pós-cirúrgicas nos pacientes submetidos à discectomia lombar em pacientes com

  13. Comparação do Índice de Torg obtido por meio de radiografia e ressonância magnética nos pacientes com mielopatia cervical espondilótica Comparación del Índice de Torg, obtenido por medio de radiografía y resonancia, en los pacientes con mielopatía espondilótica cervical Comparison of the Torg Index obtained by radiography and magnetic resonance in patients with spondylotic cervical myelopathy

    Directory of Open Access Journals (Sweden)

    Alexandre de Oliveira Zam

    2012-01-01

    Full Text Available OBJETIVO: A Mielopatia Cervical Espondilótica (MCE é uma disfunção da medula espinhal relacionada à degeneração típica do envelhecimento. No estudo de imagem podemos obter a medida do Índice de Torg, para estimar a estenose cervical. Objetivamos, assim, medir o Índice de Torg através de radiografia e ressonância magnética (RM, possibilitando verificar possíveis discrepâncias entre os métodos de medida. MÉTODOS: Realizada mensuração do Índice de Torg na radiografia e na RM da coluna cervical, sendo obtido através da relação entre a superfície posterior do corpo vertebral e o ponto mais próximo à linha laminar correspondente, dividido pelo diâmetro sagital do corpo vertebral. RESULTADOS: Participaram 29 pacientes, sendo 10 mulheres e 19 homens, com médias de idade 48,1 ± 11 anos, de peso 68,7 ± 5 Kg e de altura 1,68 ± 0,6 m. Houve diferença significativa entre o Índice de Torg calculado através de radiografia e RM, sendo menores os índices observados na RM (radiografia: 0,73 ± 0,17 vs. RM: 0,48 ± 0,14, pOBJETIVO: La Mielopatía Cervical Espondilótica (MCE es un trastorno relacionado con la degeneración de la médula espinal, típica del envejecimiento. En el estudio de imagen se puede obtener la medida del Índice de Torg para estimar la estenosis cervical. Nuestro objetivo es, por tanto, medir el índice de Torg mediante rayos-X y resonancia magnética (RM, posibilitando verificar posibles discrepancias entre los métodos de medición. MÉTODOS: Se realiza la medición del Índice de Torg en la radiografía y en la resonancia magnética de la columna cervical, siendo obtenido mediante la determinación de la relación entre la superficie posterior del cuerpo vertebral y el punto más cercano a la línea de la lámina correspondiente, dividido por el diámetro sagital del cuerpo vertebral. RESULTADOS: Participó un total de pacientes 29, siendo 10 mujeres y 19 hombres, edad promedio de 48,1 ± 11 años, peso

  14. Resonancias del liberalismo en las políticas públicas

    OpenAIRE

    García Muñoz, Claudia

    2015-01-01

    Objetivo: examinar el influjo del liberalismo en las normas y las políticas públicas en Colombia. Metodología: trabajo teórico basado en una bibliografía filosóficojurídica. Resultados: el liberalismo de la modernidad ha dejado suhuella en la manera de concebir la legalidad democrática respecto a la concepción dualista entre lo público y lo privado, y la concepción de lalibertad restringida a lo individual. No obstante, se advierten reacciones que proponen cambios en la noción de lo público y...

  15. Brennand: resonancia y universalidad de las formas Brennand: resonance and the univesality of the forms

    Directory of Open Access Journals (Sweden)

    G. CECILIA TORO

    2001-03-01

    Full Text Available Este trabajo propone la búsqueda y exposición de patrones de formas, tanto de algunas obras producidas por la naturaleza como de algunas de las obras producidas por la mano del hombre, quien como un microcosmos, que forma parte de la naturaleza recrea el macrocosmos. En una cultura en que el hombre ha perdido contacto con la naturaleza, con sus semejantes y con sus orígenes, otro objetivo de este trabajo es re emparentar al hombre con la naturaleza de la que forma parte. Se pretende mostrar al hombre, como un fractal del Universo, que es capaz de recrear, independientemente del tiempo, del espacio y de la escala de magnitudes, las mismas formas que crea el Universo, con la fuerza de la belleza en toda su pureza y en todo lo terrible con que a veces se nos presenta su aspecto. La belleza, así como la religión o como la pureza, tiene un poder redentor y el hombre anhela los paraísos perdidos. Cuando se amplia nuestra capacidad para percibir la belleza ya estamos en camino cierto, ya estamos en un camino que nos cambia desde un estado de conciencia a otro, ya estamos en un camino de regreso a la unidad. En el presente estudio se exponen algunas formas durante la diferenciación de un platelminto, Mesocestoides corti, obtenidas mediante microscopía de barrido y se exponen algunas obras de un hombre, Francisco Brennand, ganador del premio Gabriela Mistral 1993, el mayor premio dado en artes plásticas en América. Brennand, como un holograma, con un único referencial: el Universo ha recreado un Universo biológico y de increíble belleza desde su interior. En este trabajo, se pretende además exponer como, a través de la historia de nuestra cultura, el hombre justificó el anhelo y la certeza de universalidad, generando explicaciones filosóficas, psicológicas, biológicas, físicas, matemáticas, astronómicas y artísticasThis work proposes for the search and exposition of patterns of forms as they appear in nature as well as those created by man, who as a microcosm, which forms part of nature, recreates the macrocosm. In a culture in which man has lost connections with nature, with his fellow men and their origins, we also aim here to re-parentalize man within the nature from which he takes part. Man is presented as a fractal of the Universe, who, independently of time, space and scale, is able to recreate the same forms that are created by the Universe. This process will necessarily involve both the strength of beauty in its purest and most terrible forms. Beauty, as well as religion or purity, has in itself a redeeming power and man longs for lost paradises. When our ability to perceive beauty is heightened, we are already headed in the right direction; we are already following a path which changes us from one state of consciousness to another, we are already returning to a state of unity. We will show some differentiated forms of a platyhelminth worm, Mesocestoides corti, obtained under scanning electron microscopy, which are unbelievably similar to some forms originating from the work of a great artist, the sculptor Francisco Brennand, which are also shown here. Brennand was awarded the Gabriela Mistral Prize in 1993, the highest accolade for plastic arts in America. Brennand, like a hologram and with only one single point of reference _ The Universe _ has recreated a biological Universe of incredible inherent beauty. This work also aims to show that throughout the history of our own cultures, man justifies his strong desire and his certainty of universality, with explanations of all types: philosophical, psychological, biological, physical, mathematical, astronomical and artistic

  16. Resonancias de los paradigmas científicos en las arquitecturas de la Escuela de Madrid

    OpenAIRE

    Ortega Barnuevo, Gonzalo

    2014-01-01

    Los años cincuenta y sesenta son los años de la incorporación definitiva de la arquitectura española al panorama internacional. Entre los arquitectos que protagonizan ese salto sin retorno, se encuentra el grupo de aquellos que unos años más tarde serán denominados por Juan Daniel Fullaondo como Escuela de Madrid. Carlos Flores, en su libro Arquitectura Española Contemporánea 1880-1950, se refiere a esos arquitectos como aquellos que se aplicaban a la difícil tarea de restablecer en España un...

  17. Aplicaciones de la Resonancia Magnética Nuclear en el estudio de la Infertilidad

    OpenAIRE

    Piñero Sagredo, Eva Mª

    2015-01-01

    En los últimos años se ha producido una reducción en el número de nacimientos en muchos países, fundamentalmente europeos. Esta reducción puede ser debida a diversos factores que afecten a la fertilidad de la mujer tales como factores culturales, sociales y económicos que aumentan la edad de la mujer para concebir su primer hijo, causas inmunitarias, alteraciones del aparato reproductor femenino, causas hipotalámico-hipofisarias y factores relacionados con el estilo de vida entre otros. E...

  18. Dosimetry of ionizing radiations by Electron paramagnetic resonance; Dosimetria de radiaciones ionizantes por resonancia paramagnetica electronica

    Energy Technology Data Exchange (ETDEWEB)

    Azorin N, J [UAM-I, Av. San Rafael Atlixco 186, 09340 Mexico D.F. (Mexico)

    2005-07-01

    In this work, some historical and theoretical aspects about the Electron Paramagnetic Resonance (EPR), its characteristics, the resonance detection, the paramagnetic species, the radiation effects on inorganic and organic materials, the diagrams of the instrumentation for the EPR detection, the performance of an EPR spectrometer, the coherence among EPR and dosimetry and, practical applications as well as in the food science there are presented. (Author)

  19. La Resonancia J/$\\psi$ y Sus Implicaciones Para La Masa Del W

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Hernandez, Alberto [Mexico, ESFM

    1995-01-01

    Es un placer agradecer a mi asesor el doctor Heriberto Castilla Valdez por brindarme sus conocimientos, experiencia y paciencia en el desarrollo de esta tesis; tambien quiero agradecer al profesor H.E. Fisk, por su apoyo econemico en mi estancia en Fermilab. De igual forma agradezco a los doctores Arturo Fernandez Telles, Miguel Angel Perez Angen y Rebeca Juarez Wisozka quienes me introdujeron al campo de la fisica experimental de altas energfas. Agradezco tambien a Maribel Rios Cruz, Ruben Flores Mendieta, Juan Morales Corona, Fabiola Vazquez Valencia, Salvador Carrillo Moreno y Cecilia Uribe Estrada por su amistad y compaiierismo durante el desarrollo de mi maestria. Un especial agradecimiento a Ian Adam y Kina Denisenko por su valiosa ayuda, comentarios y discusiones durante mi estancia en Fermilab. Por ultimo quisiera agradecer a mis profesores, amigos y familiares quienes siempre me apoyaron y alentaron y al Consejo N acional de Ciencia y Tecnologfa asf como al Departamento de Fisica de Cinvestav por su apoyo econemlco.

  20. Comportamiento dinámico de asteroides en la resonancia 2:1

    Science.gov (United States)

    López García, F.; Brunini, A.

    El propósito de este trabajo es mostrar los resultados obtenidos del estudio del movimiento de asteroides cercanos a la conmensurabilidad 2:1 con el movimiento medio de Júpiter, analizando el comportamiento de órbitas de asteroides reales y ficticios. Se analizan los tiempos de Lyapunov obtenidos a partir de la integración de las ecuaciones del movimiento. Se han estudiado la órbitas utilizando el modelo de cinco cuerpos y se han considerado los casos planar y espacial. Las simulaciones numéricas se realizaron utilizando integradores simpléticos y el intervalo de tiempo de integración fue de T = 107 años.

  1. Modelo computacional del circuito motor basado en estudios de Resonancia Magnética Nuclear funcional

    OpenAIRE

    Karla Batista García-Ramó; Rafael Rodríguez-Rojas; Maylén Carballo-Barreda

    2012-01-01

    Los ganglios basales constituyen una compleja red de núcleos subcorticales implicados en el control motor,en la integración sensorimotora y en los procesos cognitivos. Su funcionamiento e interacción con el resto de las estructurascerebrales permanecen como una gran polémica. Este trabajo tuvo como objetivo modelar la interacción del circuito formado por los ganglios basales, el tálamo y la corteza para la selección de un programa motor, sobre la base del patrón de conectividad funcional ob...

  2. Treatment of effluent containing uranium with magnetic zeolite; Tratamento de efluente contendo uranio com zeolita magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Craesmeyer, Gabriel Ramos

    2013-07-01

    Within this work, a magnetic-zeolite composite was successfully synthesized using ferrous sulfate as raw material for the magnetic part of the composite, magnetite, and coal fly ash as raw material for the zeolitic phase. The synthesis of the zeolitic phase was made by alkali hydrothermal treatment and the magnetite nanoparticles were obtained through Fe{sup 2+} precipitation on alkali medium. The synthetic process was repeated many times and showed good reproducibility comparing the zeolitic nanocomposite from different batches. The final product was characterized using infrared spectroscopy, powder X-ray diffraction, X-ray fluorescence, scanning electron microscopy with coupled EDS. Specific mass, specific surface area and other physicochemical proprieties. The main crystalline phases found in the final product were magnetite, zeolites types NaP1 and hydroxysodalite, quartz and mullite, those last two remaining from the raw materials. Uranium removal capacity of the magnetic zeolite composite was tested using batch techniques. The effects of contact time and initial concentration of the adsorbate over the adsorption process were evaluated. Equilibrium time was resolved and the following kinetics and diffusion models were evaluated: pseudo-first order kinetic model, pseudo-second order kinetic model and interparticle diffusion model. A contact time of 120 min turned out to be enough to reach equilibrium of the adsorption process. The rate of adsorption followed the pseudo-second order model and the intra particle diffusion did not turn out to be a speed determinant step. Two adsorption isotherms models, the Langmuir model and the Freundlich model, were also evaluated. The Langmuir model was the best fit for the obtained experimental data. Using the best fitted adsorption isotherm and kinetic model, the theoretical maximum adsorption capacity of uranium over the composite was determined for both models. The maximum removal capacity calculated was 20.7 mg.g{sup -1} for the Langmuir isotherm and 23.4 mg.g{sup -1} for the pseudo-second order model. The experimental value attained was 23,3 mg.g{sup -1}. (author)

  3. Le leucodistrofie: aspetti clinici e quadri con Tomografia Computerizzata e con Risonanza Magnetica

    International Nuclear Information System (INIS)

    Magnaldi, S.

    1991-01-01

    Leukodystrophies are inherited white matter diseases due to abnormalities occurring in myelin synthesis and/or maintenance. The most common types of these rare childhood conditions are represented by adrenoleukodystrophy, metachromatic leukodystrophy, Canavan's, Alexander's, Krabbe's, and Pelizaeus-Merzbacher's diseases. Most of them are lethal during childhood, with the exception of the adrenoleukodystrophy-adrenomyeloneuropathy complex, which sometimes, during its early phases, may be cured with a dietary therapy. The aims of this paper are: 1) the description of inheritance factors, pathogenesis, pathological and clinical findings of each of the most frequent childhood leukodystrophies; 2) the description of the most common patterns of these conditions on CT and MR imaging; 3) the evaluation of the diagnostic capabilities of these two imaging techniques and the comparison of their results. Finally, some of the therapies suggested for the mild forms of these conditions are discussed. The evaluation of leukodystrophic patients with CT and MR imaging shows both imaging modalities to have high sensitivity, thanks to the detection of abnormally myelinated areas, which appear hypodense on CT and Hypertense on T2-weighted MR images. Frequently, both imaging modalities exhibit high specificity as well: they allow a differential diagnosis between the different types through the demonstration of their location in the early stages and of their mode of spread. The most typical example is represented by adrenoleukodystrophy, which is the most common type of leukodystrophy: the frequent occipito-parietal onset and the anterior and caudal progression allow a correct diagnosis to be made on CT and MR images in most cases. The comparison between CT and MR findings demonstrates a slight superiority of the latter: multiplanarity and high contrast resolution make MR imaging more sensitive than CT in the detection of the both caudal spread and involvement of optic and acoustic nervous pathways. Furthermore, MR imaging allows a safe follow-up in children with leukodystrophy

  4. Magnetic resonance imaging evaluation of traumatic muscle injuries; Avaliacao por ressonancia magnetica das injurias musculares traumaticas

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Elisa Pompeu [Santa Casa de Misericordia do Rio de Janeiro, RJ (Brazil); Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia; Coutinho Junior, Antonio Carlos; Domingues, Romulo Cortes; Domingues, Romeu Cortes [Centro Medico Barrashopping, Rio de Janeiro, RJ (Brazil). Clinica de Diagnostico por Imagem (CDPI)

    2001-12-01

    We evaluated 43 magnetic resonance scans of the leg or thigh of patients suffering from sports trauma. Strains were the most frequent lesions observed. These lesions presented iso- or hypointense signal on T1 and hyperintense signal on T2 images, and were classified according to the intensity of the injury of the fibers into grades 1, 2 and 3. The second most common lesions in these series were contusions that appeared iso- or hypointense on T1 and hyperintense on T2 images. Fibrosis was also observed as low signal lesions on T1 and T2 images. (author)

  5. Magnetic resonance imaging in schizophrenia: a morphometric study; Ressonancia magnetica na esquizofrenia: um estudo morfometrico

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Claudio Campi de [Sao Paulo Univ., SP (Brazil). Instituto do Coracao (InCor). Secao de Ressonancia Magnetica]. E-mail: campi@uol.com.br

    2001-06-01

    Thirty-three patients with chronic schizophrenia and 21 normal subjects were submitted to magnetic resonance imaging studies using a 1.5 T scanner. Axial and coronal T 2-weighted images were obtained. The volumes of the brain, intracranial, supratentorial, infratentorial and the total, ventricular and subarachnoid cerebrospinal fluid volumes were measured using semi-automated morphometric methods. The volumes of the amygdala-hippocampus complex, para hippocampal gyrus cortex, putamen, globus pallidus, temporal lobe, gray and white matter of temporal lobe were also measured. These volumes were normalized using the intracranial volume as reference. The most relevant findings observed were reduced brain volume and increased total, ventricular and subarachnoid cerebrospinal fluid volumes in patients with schizophrenia when compared to the controls. Patients with schizophrenia had also smaller amygdala-hippocampus complexes, temporal lobes and temporal lobe white matter than the controls, as well as increased putamen volumes. (author)

  6. Meniscal configuration using magnetic resonance imaging; Configuracao meniscal pela ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Arthur da Rocha C.; Turrini, Elisabete; Karoauk, Teresa C.C.; Lederman, Henrique M. [Escola Paulista de Medicina, Sao Paulo, SP (Brazil). Dept. de Diagnostico por Imagem

    1997-04-01

    The authors present a review of the normal meniscal configuration and correlation with anatomic specimens. The images were obtained by magnetic resonance imaging. The images were obtained by magnetic resonance imaging. The authors emphasize the importance of knowing the relationship between the meniscus and the adjacent anatomic structures. (author) 31 refs., 10 figs., tabs.

  7. Characterization of functional polymers by NMR; Caracterizacao de polimeros funcionalizados por ressonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Neto, Oscar H.S. A.S.; San Gil, Rosane A.S.; Nakayama, T; Costa Neto, Claudio [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica

    1994-12-31

    Several synthetic polymers are used in the chemical analysis of complexes mixtures aiming to extract certain specific functional groups for further identification. This work describes the utilization of NMR in the characterization of one of the above mentioned compounds which will be used as reagent for the synthesis of another compound of the same type, which will be further used in the chemical analysis of alcohols and phenols. The methodology is described. The results are described and discussed 4 refs., 2 figs.

  8. Nuclear magnetic resonance of randomly diluted magnetic materials; Ressonancia nuclear magnetica em materiais magneticos diluidos aleatoriamente

    Energy Technology Data Exchange (ETDEWEB)

    Magon, C J

    1986-12-31

    The temperature dependence of the nuclear relaxation rates and line shapes of the F{sub O} resonance in the diluted antiferromagnet Fe{sub x} Zn{sub 1-x} F{sub 2} and Mn{sub x} Zn{sub 1-x} F{sub 2} are studied over a large temperature range T{sub N} < {approx} T {<=} 300 K. The high (room) temperature spin-lattice relaxation rates (1/T{sub 1}) of the F{sub O} nuclei, which are not transfer hyperfine coupled to the Fe (or Mn) spins, have been measured and calculated as a function of the concentration x. Good agreement with experiment is found for the theoretical results, which have been obtained in the range 0.1 {<=} x {<=} 0.8. The temperature dependence of 1/T{sub 1} for T{sub N}

  9. Characterization of natural bentonite by NMR; Caracterizacao de bentonitas naturais por ressonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Sidnei Q.M.; Dieguez, Lidia C [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Menezes, Sonia M.C. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; San Gil, Rosane A.S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica

    1994-12-31

    Solid state NMR as well as several other instrumental chemical analysis techniques were used in order to characterize two natural occurring bentonite. The methodology is described. The NMR spectra, together with the other used techniques suggest that the observed differences are due to iron inclusions in tetrahedral and octahedral sites 5 refs., 3 figs., 5 tabs.

  10. Magnetic resonance imaging of cerebellar Schistosomiasis mansoni; Ressonancia magnetica na esquistossomose mansoni cerebelar

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Bruno Perocco; Costa Junior, Leodante Batista da [Hospital da Baleia, Belo Horizonte, MG (BRazil). Servico de Neurocirurgia; Lambertucci, Jose Roberto [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Medicina. Servico de Doencas Infecciosas e Parasitarias

    2003-10-01

    A 15-year-old boy was admitted to hospital with a history of headache, dizziness, vomiting and double vision that started two weeks before. His parents denied any previous disease. During clinical examination he presented diplopia on lateral gaze to the left and horizontal nystagmus. No major neurological dysfunction was detected. He was well built, mentally responsive and perceptive. Laboratory findings revealed a leukocyte count of 10,000/mL, a normal red blood cell count and no eosinophilia. The magnetic resonance images (MRI) of the brain showed a left cerebellar lesion with mass effect compressing the surrounding tissues. Contrast-enhanced images showed a mass like structure and punctate nodules (Figures A and B: axial and coronal contrast-enhanced T1-weighted MR images showed the nodular - yellow arrows - enhancement pattern of a left cerebellar intraxial lesion). The lesion extended to the vermis and brachium pons and compressed the medulla. There was no hydrocephalus. He was taken to the operating room with the presumptive diagnosis of a neuroglial tumor, and submitted to a lateral suboccipital craniectomy. A brown, brittle tumoral mass without a clearly defined margin with the cerebellar tissue was removed. Microscopic examination revealed schistosomal granulomas in the productive phase in the cerebellum (Figure C). After surgery, treatment with praziquantel (50 mg/kg/dia, single dose) and prednisone (1 mg/kg/day) was offered and the patient improved quickly. Thirty days later he was seen again at the outpatient clinic: he was asymptomatic and with no neurological impairment. This is the eighth case of cerebellar involvement in schistosomiasis mansoni and the second report of a tumoral form of cerebellar schistosomiasis documented by magnetic resonance images. (author)

  11. Desulphurisation of coal pyrolysis and magnetic separation. Desulfuracion de carbones mediante pirolisis y separacion magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, J.C.; Ayala, N.; Ibarra, J.V.; Moliner, R.; Miranda, J.L.; Vazquez, A. (CENIM, Madrid (Spain))

    1991-07-01

    The desulphurisation of coal intended for use inthermal power stations is a priority issue in the national strategy for the reduction of acid rain. This article studies the feasibility of eliminating pyritic sulphur from coal by physical methods using high intensity pyrolysis and magnetic separation. 6 refs., 9 figs., 4 tabs.

  12. Magnetic resonance imaging of pelvic endometriosis; Ressonancia magnetica em endometriose pelvica

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, G.P.; Martin, B.; Tubiana, J.M. [Hospital Saint Antoine, Paris (France)

    1994-07-01

    Twenty-five magnetic resonance imaging (MRI) studies were performed in 18 patients with proven endometriosis. MRI findings were analyzed and compared with laparoscopic or surgical findings; MRI accurately demonstrated ovarian endometrial cysts as well as ectopic foci of endometriosis. Adhesions may be also suggested. Contrary to laparoscopy, MRI easily depicts both deep lesions and endometrial implants under the peritoneum. Consequently, MRI appears as an useful adjunct to laparoscopy for initial diagnosis before starting a medical treatment and above all as the imaging modality of choice for evaluation of the answer to treatment, avoiding iterative and often adhesions limited laparoscopies. (author). 7 refs.; 9 figs.

  13. Magnetic resonance imaging in sudden deafness; Ressonancia magnetica em surdez subita

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Hugo Valter Lisboa; Barros, Flavia Alencar; Penido, Norma de Oliveira; Souza, Ana Claudia Valerio de; Yamaoka, Wellington Yugo [Sao Paulo Univ., SP (Brazil). Dept. de Otorinolaringologia e Cirurgia da Cabeca e Pescoco; Yamashita, Helio [Sao Paulo Univ., SP (Brazil). Dept. de Imagem e Diagnostico]. E-mail: hvlramos@gmail.com

    2005-07-15

    The etiology of sudden deafness can remain undetermined despite extensive investigation. This study addresses the value of magnetic resonance imaging in the analysis of sudden deafness patients.Study Design: transversal cohort.Material And Method: In a prospective study, 49 patients attended at otolaryngology emergency room of Federal University of Sao Paulo - Escola Paulista de Medicina, from April 2001 to May 2003, were submitted to magnetic resonance imaging.Results: Magnetic Resonance abnormalities were seen in 23 (46.9%) patients and revealed two tumors suggestive of meningioma, three vestibular schwannomas, thirteen microangiopathic changes of the brain and five (21.7%) pathological conditions of the labyrinth.Conclusion: Sudden deafness should be approached as a symptom common to different diseases. The presence of cerebellopontine angle tumors in 10.2% of our cases, among other treatable causes, justifies the recommendation of gadolinium-enhanced magnetic resonance use, not only to study the auditory peripheral pathway, but to study the whole auditory pathway including the brain. (author)

  14. Quistes de los maxilares

    Directory of Open Access Journals (Sweden)

    Ivan Alberto Manotas Arevalo

    2013-12-01

    Full Text Available Los Grandes Quistes de los Maxilares han estado vinculados siempre a la humanidad, desde tiempos remotos, pues han sido halladas en restos de especimenes fosiles, han llamado la atencion de los clínicos, en torno a su etiologia, en la que se ha introducido la participacion de la genetica, (demostrada en el desarrollo de los queratoquistes maxilares, la fisiopatologia, caracteristicas histologicas (inmunohistoquimica, posibilidades diagnosticas por la imagen, (como la tomografia computarizada y la resonancia nuclear magnetica y otras pruebas. Además llaman la atención al estudio, por sus alternativas de manejo especialmente las formas radicales, y el analisis de asociaciones a otras patolo-gias benignas y malignas, y de la recurrencia muy alto de algunas de estas lesiones. Mucho se ha desarrollado para elucidar su naturaleza real, estadificar adecuadamente la lesion descartando asocia-ciones patologicas sindromicas, indicar un tratamiento apropiado, y realizar seguimientos a largo plazo. Este articulo pretende recaudar una information general que de parametros para abordar el estudio de los quistes maxilares a partir de la presentacion de un caso clinico.

  15. Multiple sclerosis test or the 4 humors: cerebrospinal fluid serum, tears and saliva; Esclerosis multiple test de los 4 humores: liquido cefalorraquideo, suero, lagrimas y saliva

    Energy Technology Data Exchange (ETDEWEB)

    Oehninger Gatti, C; Buzo Del Puerto, R; Chouza Antelo, C; Scotti Bianchi, C; Cibils, D; Alcantara Pelaez, J; Gomez, A; Heuguerot Oliveira, C

    1994-12-15

    4 were studied biological fluids easily accessible to the immune exploration (cerebrospinal fluid, serum, tears and saliva) in 25 patients with Multiple Sclerosis (MS) during a push clinical disease. The level of interleukin-2 receptor soluble (RsIL-2) was significantly increased by at least 3 of these 4 fluids, compared with normal controls. The sensitivity and specificity of its determination for the diagnosis of the condition was higher than other immunochemical parameters, oligoclonal distribution (OD) of immunoglobulin (Ig) light chain imbalance-and-evoked electrophysiological studies. This method is used to establish a more accurate diagnosis of Multiple Sclerosis as well as to monitor its biological activity with nuclear magnetic resonance (NMR) (Author) [Spanish] Se estudiaron 4 fluidos biologicos de facil acceso a la exploracion inmune (liquido cefalorraquideo, suero, lagrimas y saliva) en 25 pacientes con Esclerosis Multiple (EM) obtenidos durante un empuje clinico de la enfermedad. El nivel del receptor de Interleukina-2 soluble (RsIL-2) se encontro significativamente aumentado en por lo menos 3 de estos 4 fluidos, en comparacion con el de los controles normales. La sensibilidad y especificidad de su determinacion para el diagnostico de la afeccion, fue mayor que la de otros parametros inmunoquimicos - distribucion oligoclonal (DO) de inmunoglobulinas (Ig), disbalance de cadenas livianas - y estudios electrofisiologicos -potenciales evocados-. Este metodo es utilizado para establecer un diagnostico mas certero de la Esclerosis Multiple asi como tambien para monitorizar su actividad biologica junto con la resonancia magnetica nuclear (RMN)(Author)

  16. Reprodutibilidade intra e interobservadores da classificação de hipersinal facetário lombar e correlação com a degeneração discal para ressonância magnética Reproducibilidad intra e inter observadores de la clasificación de hiperseñal facetaria lumbar y correlación con la degeneración discal para resonancia magnética Intraobserver and interobserver reproducibility of lumbar facet hypersignal rating and correlation with disc degeneration by magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    André Evaristo Marcondes César

    2011-01-01

    Full Text Available OBJETIVO: Avaliar a reprodutibilidade intra e interobservadores da "classificação de hipersinal facetário lombar" e avaliar a correlação com a degeneração discal. MÉTODOS: Estudo retrospectivo de imagens de ressonância magnética obtidas de 41 (N=41 pacientes (18 homens e 23 mulheres, com idade variando de 26 a 84 anos, com média de 48 anos e três meses. As imagens foram revisadas por três ortopedistas especialistas em cirurgia de coluna e um radiologista, para avaliar e quantificar a presença do hipersinal facetário lombar. Posteriormente, foi verificada a relação entre a artrose facetária e degeneração discal. RESULTADOS: Foram avaliados e classificados 205 discos lombares e suas facetas articulares pelos quatro examinadores, com os dados analisados pelo Teste de Cronbach e da Análise de Correlação de Spearman com resultados estatisticamente elevados, confirmando boa relação intra e interobservadores para a "classificação de hipersinal facetário". Não foi observada relação estatisticamente significante entre artrose facetária e degeneração discal. CONCLUSÃO: Foram obtidos resultados suficientes para afirmar que existe boa relação intra e interobservadores para a "classificação de hipersinal facetário lombar". Não se verificou relação estatisticamente significante entre artrose facetária e degeneração discal.OBJETIVO: Evaluar la reproducibilidad inter e intra observadores de la "Clasificación de hiperseñal facetaria lumbar" y evaluar la correlación con la degeneración discal. Métodos: Estudio retrospectivo de imágenes de resonancia magnética obtenidas de 41 (N=41 pacientes (18 hombres y 23 mujeres, con la edad de 26 años hasta 84 años y, con promedio de 48 años y 3 meses. Las imágenes fueran revisadas por tres cirujanos ortopedistas especialistas en cirugía de columna vertebral y un radiólogo para evaluar y cuantificar la presencia de hiperseñal facetario lumbar. Después fue verificada

  17. Saddle-Point Rotational States from Resonance Fission of Oriented Nuclei; Etats Rotationnels a l'Etranglement Resultant de la Fission, par Neutrons de Resonance, de Noyaux Orientes; 0412 0420 0410 0429 0410 0422 0415 041b 042c 041d 042b 0415 0421 041e 0421 0422 041e 042f 041d 0418 042f 0421 0415 0414 041b 041e 0412 041e 0419 0422 041e 0427 K 0418 0412 0420 0415 0417 0423 041b 042c 0422 0410 0422 0415 0420 0415 0417 041e 041d 0410 041d 0421 041d 041e 0413 041e 0414 0415 041b 0415 041d 0418 042f 041e 0420 0418 0415 041d 0422 0418 0420 041e 0412 0410 041d 041d 042b 0425 042f 0414 0415 0420 ; Estados Rotacionales en el Punto de Estrangulacion Debidos a la Fision por Resonancia de Nucleos Orientados

    Energy Technology Data Exchange (ETDEWEB)

    Dabbs, J. W.T.; Walter, F. J.; Parker, G. W. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1965-07-15

    valeurs de J dans {sup 235}U, on a procede a un ajustement a of analogue a celui de Kirpichnikov et al., pour lequel il avait ete admis que J (0,3 eV) etait different de J (1,14 eV), contrairement a ce qui avait ete fait pour des ajustements a plusieurs niveaux anterieurs. Ces donnees preliminaires sont compatibles avec une anisotropie proportionnelle a la contribution a of des deux valeurs de J possibles, qui a ete calculee. Toutefois, la forme de la courbe n'est pas en accord avec d'autres donnees, telles que la variation du rapport 'sommet-vallee ' de Faler et Tromp; en consequence, bien qu'elle paraisse extremement plausible, l'hypothese Selon laquelle J (0,3 eV) est different de J (1,14 eV) ne doit pas encore etre consideree comme demontree. On procede actuellement a de nouvelles mesures. (author) [Spanish] Los nucleos de los elementos actinidos uranio, neptunio y plutonio pueden alinearse en los compuestos del tipo XO{sub 2}Rb(NO{sub 3}){sub 3}, en virtud de la interaccion del momento cuadripolar del nucleo con el gradiente del campo electrico cristalino, por simple enfriamiento del monocristal correspondiente. Una alineacion nuclear de este tipo corresponde a una distribucion angular no uniforme del eje de simetria del nucleo compuesto en el espacio, que refleja principalmente el valor de K. Si se supone que los fragmentos presentan tambien la misma distribucion, se obtiene un metodo para determinar el numero cuantico K en el punto de estrangulacion. Como se menciona en trabajos anteriores, en el Oak Ridge National Laboratory se han realizado experimentos con nucleos alineados de {sup 233}U y de {sup 235}U a 1,2 Degree-Sign K utilizando neutrones termicos. Dichos experimentos se han ampliado ahora a energias neutronicas de resonancia y a temperaturas de 0, 5 Degree-Sign K. Si se considera juntamente con la determinacion directa (mediante neutrones y nucleos polarizados) de los valores J asociados a cada resonancia, esa ampliacion permite llegar a un conocimiento

  18. Ternary Fission of U{sup 235} by Resonance Neutrons; Fission Ternaire de {sup 235}U par des Neutrons de Resonance; 0422 0420 041e 0419 041d 041e 0415 0414 0415 041b 0415 041d 0418 0415 0423 0420 0410 041d 0410 -235 041d 0410 0420 0415 0417 041e 041d 0410 041d 0421 041d 042b 0425 041d 0415 0419 0422 0420 041e 041d 0410 0425 ; Fision Ternaria del {sup 235}U por Neutrones de Resonancia

    Energy Technology Data Exchange (ETDEWEB)

    Kvitek, I.; Popov, Ju. P.; Rjabov, Ju. V. [Ob' edinennyj Institut Jadernyh Issledovanij, Dubna, SSSR (Russian Federation)

    1965-07-15

    feuille d'aluminium) on a procede a une mesure pour laquelle le volume ou la particule a long parcours etait enregistree se trouvait protege par un filtre d'aluminium supplementaire de 1 mm d'epaisseur. Les resultats de experience montrent que le rapport encre les fissions ternaire et binaire de {sup 235}U ne subit pas les fortes variations signalees par d'autres auteurs. Au cours des mesures on n'a constate aucune irregularite dans le rapport entre les sections efficaces pour les energies de 0,1 a 0,2 eV. Les auteurs du memoire examinent l'influence eventuelle de la reaction (n, {alpha}) sur les resultats des experiences pour lesquelles on nTa pas eu recoure a la coincidence entre particules a long parcours et fragments de fission. (author) [Spanish] Recientemente se han publicado varios trabajos acerca de la existencia de una variacion considerable en la razon de la seccion eficaz de fision ternaria a la seccion eficaz de fision binaria para el {sup 235}U, al pasar de una resonancia neutronica a otra. Hasta la fecha los autores no han descubierto ninguna variacion de esa indole para el {sup 235}U ni para el {sup 239}Pu. En la presente memoria se presentan los resultados del estudio de la fision ternaria del {sup 235}U inducida por neutrones de 0,1 a 30 eV de enetgia. A diferencia de otros trabajos sobre fision ternaria del {sup 23}'5U, el suceso de fision ternaria se identifico por coincidencia de uno de los fragmentos de fision con una particula ligera de laigo alcance. Esto permitio separar las fisiones ternarias de la posible contribucion de la reaccion (n, ex). Las mediciones se efectuaron en el reactor pulsado de neutrones rapidos del Instituto Central de Investigaciones Nucleares, por el metodo del tiempo de vuelo. La trayectoria de vuelo era de 100 m, lo que permitia lograr un poder de resolucion de 0,6 {mu}s/m. Los fragmentos de fision y las particulas ligeras de largo alcance se registraron por medio de contadores de centelleo gaseosos, llenos de xenon a 2 atm

  19. Resonancia magnética de las glándulas salivales parótida y submaxilar

    OpenAIRE

    Hernández-rodríguez, María Cristina; Martín-pérez, Manuel Ángel; Marín-balbín, José Martín; Blanco-hernández, Rodrigo; Martín-garcía, Ignacio; Tabernero-rico, Roberto Domingo

    2017-01-01

    Introduction and objective: Salivary glands are divided in major and minor, including tissue distributed by the upper airway. There are numerous entities which can affect these structures conditioning various types of pathology. Given the greater importance of the submandibular and parotid gland, this article focuses on their study. Method: A retrospective review of patients underwent MRI studies with known or suspected pathology of salivary glands was made, over five years (2011-2015), assum...

  20. RESONANCIA ELECTRICA EN EL RANGO THETA (0) EN NEURONAS DE LA CAPA II DEL NUCLEO CORTICAL ANTERIOR DE LA AMIGDALA

    OpenAIRE

    PEZZOLI GONZALEZ; MAURIZIO FERNANDO; PEZZOLI GONZALEZ; MAURIZIO FERNANDO

    2010-01-01

    El complejo de la amígdala participa en procesar información sensorial relevante desde el punto de vista emocional. La información sensorial olfativa entra desde el bulbo olfatorio (OB) a este complejo a través de la corteza olfatoria, la cual incluye los núcleos corticales de la amígdala. En ratas las neuronas mitrales del OB y aquellas de la capa II del núcleo cortical anterior (ACo) y la corteza periamigdaloide división medial (P A Cm) presentan oscilaciones intrínsecas del ...

  1. RESONANCIA ELECTRICA EN EL RANGO THETA (8) EN NEURONAS DE LA CAPA II DEL NUCLEO CORTICAL ANTERIOR DE LA AMIGDALA

    OpenAIRE

    PEZZOLI GONZALEZ, MARURIZIO FERNANDO

    2010-01-01

    El complejo de la amígdala participa en procesar información sensorial relevante desde el punto de vista emocional. La información sensorial olfativa entra desde el bulbo olfatorio (OB) a este complejo a través de la corteza olfatoria, la cual incluye los núcleos corticales de la amígdala. En ratas las neuronas mitrales del OB y aquellas de la capa II del núcleo cortical anterior (ACo) y la corteza periamigdaloide división medial (P A Cm) presentan oscilaciones intrínsecas del potencial de...

  2. Resonancia magnética nuclear de encéfalo en pacientes con fenilcetonuria diagnosticada tardíamente

    OpenAIRE

    Jiménez-Pérez, Mario O.; Gómez-Garza, Gilberto; Ruiz-García, Matilde; Fernández-Lainez, Cynthia; Ibarra-González, Isabel; Vela-Amieva, Marcela

    2015-01-01

    Antecedentes: la fenilcetonuria clásica es una encefalopatía genética caracterizada por una inhabilidad de los individuos para metabolizar la fenilalanina, por lo que su concentración plasmática se eleva a niveles tóxicos. Clínicamente se manifiesta como irritabilidad, alteración del sueño, indiferencia al medio, crisis convulsivas, retraso del neurodesarrollo, conducta autista, agresividad y discapacidad intelectual. Objetivo: describir los hallazgos y cuantificar el coeficiente de difusión ...

  3. Resonancia magnética nuclear de encéfalo en pacientes con fenilcetonuria diagnosticada tardíamente

    OpenAIRE

    Mario O. Jiménez-Pérez; Gilberto Gómez-Garza; Matilde Ruiz-García; Cynthia Fernández-Lainez; Isabel Ibarra-González; Marcela Vela-Amieva

    2015-01-01

    Antecedentes: la fenilcetonuria clásica es una encefalopatía genética caracterizada por una inhabilidad de los individuos para metabolizar la fenilalanina, por lo que su concentración plasmática se eleva a niveles tóxicos. Clínicamente se manifiesta como irritabilidad, alteración del sueño, indiferencia al medio, crisis convulsivas, retraso del neurodesarrollo, conducta autista, agresividad y discapacidad intelectual. Objetivo: describir los hallazgos y cuantificar el coefic...

  4. Resonancias de la ficción: Una lectura post-política de El fiord, de Osvaldo Lamborghini.

    Directory of Open Access Journals (Sweden)

    Mario Aznar Pérez

    2016-12-01

    Full Text Available Este trabajo plantea una aproximación a El fiord (1969, del autor argentino Osvaldo Lamborghini, desde la óptica contemporánea del lector post-político. Entendiendo este último concepto como espacio epistémico y no como una mera estrategia política, nos preguntamos: ¿qué queda de un texto marcadamente ideológico cuando es leído desde una sociedad sin ideologías? ¿Puede el contenido político de un texto literario mantener su vigencia en el tiempo? Para tratar de responder a estas cuestiones proponemos la revisión de algunos conceptos importantes como son el de «literatura política» o el de «transgresión», a la luz de una teoría del texto orgánica y en constante movimiento

  5. Stochastic heating in the cyclotron resonance of electrons; Calentamiento estocastico en la resonancia ciclotronica de los electrones

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C.; Hernandez A, O. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    The study of the different schemes of plasma heating by radiofrequency waves is a very actual problem related with the plasma heating in different machines and the particle acceleration mechanisms. In this work, it is obtained the expression for the temporal evolution of the energy absorbed in the cyclotron resonance of electrons where it is showed the stochastic character of the energy absorption. It is obtained the stochastic criteria in a magnetic configuration of an Ecr type plasma source. (Author)

  6. Seeking tools for image fusion between computed tomography, structural and functional magnetic resonance methods for applications in neurosurgery; Ferramentas para fusao de imagens dos metodos de tomografia computadorizada, ressonancia magnetica e ressonancia magnetica funcional para aplicacao pre-neurocirurgica

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Liana Guerra Sanches da, E-mail: liana@einstein.br [Departamento de Diagnostico por Imagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo (SP) (Brazil); Amaro Junior, Edson [Faculdade de Medicina, Universidade de Sao Paulo - USP, Sao Paulo, SP (Brazil). Deptartamento de Diagnostico por Imagem; Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil)

    2012-04-15

    To evaluate tools for the fusion of images generated by tomography and structural and functional magnetic resonance imaging. Methods: Magnetic resonance and functional magnetic resonance imaging were performed while a volunteer who had previously undergone cranial tomography performed motor and somatosensory tasks in a 3-Tesla scanner. Image data were analyzed with different programs, and the results were compared. Results: We constructed a flow chart of computational processes that allowed measurement of the spatial congruence between the methods. There was no single computational tool that contained the entire set of functions necessary to achieve the goal. Conclusion: The fusion of the images from the three methods proved to be feasible with the use of four free-access software programs (OsiriX, Register, MRIcro and FSL). Our results may serve as a basis for building software that will be useful as a virtual tool prior to neurosurgery. (author)

  7. Evaluation of epileptogenic focus in temporal lobe: correlation between ictal brain SPECT, magnetic resonance imaging and magnetic resonance spectroscopy; Avaliacao de foco epileptogenico do lobo temporal: correlacao entre SPECT ictal, ressonancia magnetica e ressonancia magnetica com espectroscopia de protons

    Energy Technology Data Exchange (ETDEWEB)

    Diegues, Maria Elena Martins [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear]. E-mail: emartyns@terra.com.br; Pellini, Marcos Pinto; Alves-Leon, Soniza Vieira [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina; Domingues, Romeu Cortes [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil)

    2004-02-01

    The purpose of this study was to determine the degree of concordance between radiological and radioisotopic methods and, if positive, to evaluate the usefulness of ictal SPECT in the localization of the epileptogenic focus. Ictal brain SPECT, magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) were performed on six patients with refractory temporal lobe epilepsy. Ictal SPECT was performed after withdrawal of the anti-epileptogenic drugs during video-EEG monitoring, using {sup 99m}Tc-ECD, administered to patients at the time of the ictus. MRI was performed in T1, T2 and FLAIR sequences and MRS was obtained using the PRESS technique, with a single voxel positioned in both hippocampi. The statistical analysis included the determination of the values of Kappa (k), standard error (se) and significance level (p) for the lateralization of the ictal focus. The analysis of all findings was based on EEG localization of the ictal discharge, seizure duration (109-280 s; 152 s average) and time of radiotracer injection (30-262 s; 96 s average). We obtained correlated data in four patients (67 per cent) and values of k = 0.67, se = 0.38, and p 0.041. We concluded that there is a concordance between ictal SPECT, MRI and MRS data and the usefulness of the radioisotopic procedure is related to a non diagnostic EEG and when there is a discordant or misleading diagnosis after a comparative analysis of EEG and MRS. (author)

  8. Hallervorden Spatz syndrome: magnetic resonance findings. Case report; Sindrome de Hallervorden Spatz: achados na ressonancia magnetica. Relato de caso

    Energy Technology Data Exchange (ETDEWEB)

    Farage, Luciano; Castro, Mario Augusto Padula; Macedo, Tulio Augusto Alves [Universidade Federal de Uberlandia, MG (Brazil). Hospital de Clinicas. Setor de Radiologia; Assis, Marcelo Cardoso de [Universidade Federal de Uberlandia, MG (Brazil). Faculdade de Medicina. Dept. de Cirurgia; Souza, Lincoln Pereira de; Freitas, Luiz Oliveira de [Universidade Federal de Uberlandia, MG (Brazil). Dept. de Clinica Medica

    2004-09-01

    Hallervorden-Spatz syndrome is a neuro degenerative disease, autosomic recessive with two clinical features: early and late onset. Psychiatric, pyramidal and extrapyramidal signs are present in the late subtype. We report the case of a 41-old woman with extrapyramidal signs. Magnetic resonance imaging (MRI) showed the eye-of-the-tiger sign in the medial globus pallidus. This is due to a gliosis (increased signal) and accumulation of surrounding iron (decreased signal intensity) in long T R sequences. There is a strong relationship between MRI findings and the gene mutation responsible for this disease. It makes the MRI sensible for diagnosing this syndrome. (author)

  9. In vitro absolute metabolic quantification by magnetic resonance spectroscopy; Quantificacao metabolica absoluta in vitro por espectroscopia de ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Felipe R.; Salmon, Carlos E.G. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica], e-mail: garrido@ffclrp.usp.br

    2010-03-15

    In this project we estimated characteristic nuclear relaxation times (T1 and T2) from {sup 1}H in vitro of water and the following human brain metabolites: N-Acetyl-Aspartate (NAA), Choline (Cho), Creatine (Cr) and Myo-Inositol (M-Ins) using nuclear magnetic resonance spectroscopy, aiming at relaxation effects correction for absolute quantification. Phantoms with 300 mL of a standard solution with a metabolite were used for spectra acquisition. Variable eco time sequences were used to determinate T2 while variable repetition or inversion time was used for T1 determination. Spectra processing was done with MRUI and LCModel software. Origin 8.0 was used for data fitting. The following T1/T2 values (ms) were the best estimated according to calculated absolute concentration analyses: (4061/934) for water, (1800/830) for NAA, (2316/717) for Cr, (2356/1095) for Cho and (1537/531) for M-Ins. With MRUI better results were obtained in T1 and T2 determination for relaxation effects correction in the absolute quantification process. (author)

  10. Magnetic shape memory alloys: Basic properties and applications; Aleaciones magneticas con memoria de forma: propiedades basicas y aplicaciones

    Energy Technology Data Exchange (ETDEWEB)

    Barandiaran, J. M.; Lazpita, P.; Guiterrez, J.; Garcia Arribas, A.; Feuchtwanger, J.; Asua, E.; Etxebarria, V.; Chernenko, V. A.

    2010-07-01

    These materials can undergo large deformations when subjected to external stresses when they are in the phase low temperature due to the super elasticity property. Super elasticity properties and memory effect form derived from the martensitic transformation, which thermoelastic transformation is involved in effort as well as temperature. The transformation autoacomodante called for a single crystal phase austenite gives rise to several crystals spontaneously martensite with their axes oriented in different directions to accommodate the deformation of the network. These crystals called variant or twins and their movement and change orientation gives rise to the super elasticity. (Author) 3 refs.

  11. Nuclear magnetic resonance of D(-)-{alpha}-amino-benzyl penicillin; Ressonancia magnetica nuclear da D(-)-{alpha}-amino-benzil penicilina

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Monica R.M.P.; Gemal, Andre L.; San Gil, Rosane A.S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Menezes, Sonia M.C. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    1995-12-31

    The development of new drugs from penicillins has induced the study of this substances by nuclear magnetic resonance. Several samples of D(-)-{alpha}-amino-benzyl penicillin were analysed using {sup 13} C NMR techniques in aqueous solution and solid state. Spectral data of this compounds were shown and the results were presented and analysed 7 figs., 4 tabs.

  12. Use of magnetic resonance imaging in the diagnosis of chondromalacia patella; Ressonancia magnetica no diagnostico da condromalacia de patela

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Maxime Figueiredo de Oliveira; Fernandes, Artur da Rocha Correa; Freire Filho, Edison de Oliveira; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: maximefreire@ig.com.br; Juliano, Yara; Novo, Neil Ferreira [Universidade Santo Amaro (UNISA), SP (Brazil). Faculdade de Medicina; Carneiro Filho, Mario [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Ortopedia e Traumatologia; Silva, Debora da Costa [Universidade Santo Amaro (UNISA), SP (Brazil). Faculdade de Odontologia

    2006-01-15

    Patellar articular cartilage lesions are very common and due to the dissociation between signs and symptoms and the stage of the chondral lesions the diagnostic method of choice is magnetic resonance imaging. Therefore, radiologists should be familiar with chondral abnormalities in order to correctly diagnose this condition. (author)

  13. Blood-labyrinth barrier changes. MR assessment; Alterazioni della barriera emato-labirintica. Valutazioni mediante Risonanza Magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Manfre' , L.; Bencivinni, F.; Caronia, A.; Angileri, T.; Manasia, G.; De Maria, M. [Palermo Univ., Palermo (Italy). Ist. di Radiologia P. Cignolini

    1999-12-01

    Recent progress in Magnetic Resonance Imaging (MRI), with contrast-enhanced and steady-state sequences, allows fine depiction of labyrinth abnormalities related to neoplastic, inflammatory, ischemic, degenerative or traumatic disorders. The case of 488 patients with sensorineural hearing loss, vertigo or dizziness, but normal CT findings, was examined to evaluate MR capabilities in showing labyrinth conditions. In the period between January 1994 and May 1998, they were all submitted to CT. 68 of them, with normal CT findings, were also examined with MRI, which was performed using quadrature with MRI, which was performed using quadrature head or surface coils and a single dose (0.1. mmol/kg) Gd-DTPA administration. Conventional T1 and T2 high resolution SE images were acquired. The labyrinth was studied of 52 patients with normal CT findings and no abnormalities in the cerebello-pontine angle or internal auditory canal. 14 of 52 patients (27%) exhibited labyrinth enhancement from tumor (5%), hemorrhage (3%), infection (15%), surgical (2%) or radiosurgical (2%) procedures. GRASS (Gradient Recalled At Steady-State) sequences allowed differentiation of mass lesions (e.g. tumors, clots) from other conditions. In inflammatory conditions, enhancement is not always diffuse, as expected, but may be focal. Spontaneous hemorrhages can account for labyrinth enhancement. In neoplastic conditions, enhancement may persist for as many as 6 months, and a mass effect against labyrinthine fluids may appear on GRASS images. Although there are no reports on labyrinthine degeneration after radiation therapy, one of the patients submitted to irradiation 7 years previously, had focal bilateral cochlear enhancement, which suggested a correlation with previous treatment. [Italian] Il perfezionamento della tecnica RM, grazie all'uso del mdc paramagnetico e di sequenze sensibili al flusso labirintico, ha rivoluzionato il ruolo della metodica nello studio dell'orecchio interno, consentendo la diagnosi di malattie labirintiche di natura flogistica, neoplastica, ischemica, traumatica, iatrogena o degenerativa. Scopo del lavoro e' stato quello di valutare l'uso della metodica RM contrastografica nei pazienti affetti da disturbi clinici di origine labirintica. Nel periodo compreso tra gennaio 1994 e maggio 1998, 488 pazienti affetti da sintomatologia labirintica (ipoacusia neurosensoriale, vertigini e/o acufeni) sono stati sottoposti a TC: di questi, 68 con quadro normale sono stati sottoposti a studio mediante RM e sequenze Spin-Echo T1- e T2 pesate, prima e dopo somministrazione di mdc. L'indagine e' stata ultimata dal bilancio con scansioni in tecnica steady-state per lo studio dei fluidi endolabirintici. In 14/52 (26%) pazienti e' stata dimostrata accentuazione delle componenti dell'orecchio interno, dipendente da lesioni espansive (5%), emorragiche (3%), flogistiche (15%), chirurgiche (2%), o degenerative (2%). Il comportamento delle lesioni espansive alla sequenza in tecnica di steady-state e' differito da quello rilevato nelle lesioni con altra natura. Tra le cause piu' frequenti si e' rilevata la presenza di presunti tumori intralabirintici: l'effetto massa della lesione e' tradito dall'immagine di minus nelle immagini in RM nella sequenza steady-state per il blocco del flusso endolabirintico, a differenza di quanto rilevato nella flogosi labirintica. Un'accentuazione fisiologica di componenti isolate del labirinto membranoso e' stata rilevata anche nel monitoraggio di paziente sottoposta a exeresi di schwannoma dell'ottavo paio di nervi cranici, e in seguito a pregressa radioterapia effettuata per adenocarcinoma rinofaringeo.

  14. STUDIO DELLE AREE VISIVE IN PAZIENTI CON NEUROFIBROMATOSI DI TIPO 1 E GLIOMA DELLE VIE OTTICHE MEDIANTE RISONANZA MAGNETICA FUNZIONALE

    OpenAIRE

    Lucchetta, Marta

    2015-01-01

    Neurofibromatosis 1 (NF1) is an autosomal dominant condition characterized by neuro-cutaneous involvement and a predisposition to tumour development. The most common NF1-associated central nervous system tumour is optic pathway glioma (OPG), affecting about 15% of NF1 patients and characterized by an unpredictable evolution with no clear prognostic factors identified so far. Resting-state fMRI has recently emerged as a powerful tool for functional brain analysis, allowing the examination ...

  15. Application of nuclear magnetic resonance in osteoporosis evaluation; Aplicacoes de ressonancia magnetica nuclear na avaliacao de osteoporose

    Energy Technology Data Exchange (ETDEWEB)

    Giannoni, Ricardo A., E-mail: giannoni@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Montrazi, Elton T.; Bonagamba, Tito J., E-mail: elton.montrazi@gmail.com, E-mail: tito@ifsc.usp.br [Universidade de Sao Paulo (IFSC/USP), Sao Carlos, SP (Brazil). Inst. de Fisica; Cesar, Reinaldo, E-mail: reinaldofisica@gmail.com [Universidade de Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). Escola de Engenharia

    2013-07-01

    In this work, initially ceramic samples of known porosity were used. These ceramic samples were saturated with water. The nuclear magnetic resonance signal due to relaxation processes that the hydrogen nucleus water contained in the pores of this ceramic material was measured. Then these samples were subjected to a process of drying and measures successively. As the water contained in pores greater evaporates the intensity of signal decreases and shows the sign because of the smaller pores. The analysis of this drying process gives a qualitative assessment of the pore size of the material. In a second step, bones of animals of unknown porosity underwent the same methodology for evaluating osteoporosis. Also a sample of human vertebra in a unique manner, with the same purpose was measured. Combined with other techniques is a quantitative evaluation of the possible porosity.

  16. Design of radiofrequency coils for NMR imaging; Desenvolvimento de bobinas de radiofrequencia para geracao de imagens por ressonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Maria Angelica

    1988-07-01

    In this work we describe and analyse different types of radiofrequency coils for NMR Imaging. Our system operates with a superconducting magnet, 22.5 cm bore, at 2.0 Tesla (85 MHz, resonant frequency for protons). Distinct structures, frequently described in the specialized literature, are discussed here. Usually the RF coils proposed are resonant circuits with distributed inductance and capacitance. We have built different types of resonators and its performance were compared. With the resonators developed here we have been able to obtain proton density images of good quality. (author)

  17. Nuclear magnetic resonance in superionic conductors with fluorite-type structure; Ressonancia magnetica nuclear em condutores superionicos de estrutura fluorita

    Energy Technology Data Exchange (ETDEWEB)

    Souto, Sergio Paulo Amaral

    1991-12-31

    The {sup 19} F NMR relaxation times T{sub 1} and T{sub 2} were measured in ternary and nonstoichiometric compounds with the fluorite-type structure. We have studied the Na{sub 0-4} Y{sub 0-6} F{sub 2-2} crystal in the temperature range 600 K to 900 K, where the crystal has not the fluorite structure. The T{sub 1} values were measured in 2 Larmor frequencies: 20.42 MHz and 34.24 MHz. The results for T{sub 1} were seem to be qualitatively similar to those measured in the system with two inequivalent sublattices. The T{sub 2} measurements, in the Pb{sub O84} Bi{sub 0-16} F{sub 2-16} crystal, were made during temperature cycles in the range of 300 K to 830 K. The difference in activation energy between cooling and heating half cycles, found to be approximately 0.08 eV, appear to be associated with the change in the clusters structure and not to the energy of defect formation. Finally, similar T{sub 2} measurements during temperature cycling was made in K{sub 0-4} Bi{sub 0-6} F{sub 2-2} : 2% Pb F{sub 2} crystal, in the temperature range 300 K to 800 K, but in this case no difference in the cooling and heating results was observed. We also measured, in the same temperature range, the T{sub 1} relaxation time in 3 Larmor frequencies: 11.71 MHz, 20.42 MHz and 34.24 Mhz. This results appear to indicate the existence of two hopping mechanism. (author). 132 refs., 68 figs.

  18. High resolution spectroscopy in solids by nuclear magnetic resonance; Espectroscopia de alta resolucao em solidos por ressonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Bonagamba, T J

    1991-07-01

    The nuclear magnetic resonance (NMR) techniques for High Resolution Spectroscopy in Solids are described. Also the construction project of a partially home made spectrometer and its applications in the characterization of solid samples are shown in detail. The high resolution spectrometer used is implemented with the double resonance multiple pulses sequences and magic angle spinning (MAS) and can be used with solid and liquid samples. The maximum spinning frequency for the MAS experiment is in excess of 5 Khz, the double resonance sequences can be performed with any type of nucleus, in the variable temperature operating range with nitrogen gas: -120{sup 0} C to +160{sup 0} C, and is fully controlled by a Macintosh IIci microcomputer. (author).

  19. Characterization of a tannin by NMR; Caracterizacao de um tanino elagico por espectrometria de ressonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Antonio C.F.; Silva, Antonio J.R. da [Universidade Federal, Rio de Janeiro (Brazil). Nucleo de Pesquisas de Produtos Naturais

    1994-12-31

    This work presents the observations performed during the process of characterization of Geraniin, a crystalline tannin, which is able to undergo hydrolysis, isolated from Phyllanthus tennellus, a plant known in Brazil as `quebra-pedra`. The methodology is presented and the chemical analysis performed for the identification are presented and discussed. The obtained results are compared to the existing literature 5 refs., 2 figs., 8 tabs.

  20. Proceedings of the nuclear magnetic resonance user meeting. Anais do Encontro de Usuarios de Ressonancia Magnetica Nuclear

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    Studies on utilization of nuclear magnetic resonance, such as: chemical analysis in complexes and organic compounds; structures and magnetic properties of solids; construction of images and; spectrometer designs, are presented. (M.C.K.).

  1. Nuclear magnetic resonance studies in solid polymeric electrolyte. Estudos por ressonancia magnetica nuclear em eletrolitos polimericos solidos

    Energy Technology Data Exchange (ETDEWEB)

    Donoso, J P; Mattoso, L H.C.; Cavalcante, M G [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica e Quimica; Gorecki, W; Berthier, C; Armand, M [Universite J. Fourier, Grenoble (France)

    1990-01-01

    Solid complexes formed between Poly (ethylene oxide) and various alkali metal salts, are generally referred to as polymer electrolytes conductivity and NMR properties were investigated in POE - Li Cl sub(7)O sub(4) and POE - Li BF sub(4) complexes. Our sup(1)H, Li and sup(19)F relaxation study suggest that cation motion is controlled by segmental motions of the polymer chain while the anion have additional mobility associated with BG sub(4) rotation. (author).

  2. Selection of multislice in nuclear magnetic resonance tomography. Selecao de multiplos planos em tomografia por ressonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Frare, Junior, P L

    1990-01-01

    The study and the implementation of three techniques for the selection of multislice, aiming the optimization of the NMR tomography is presented. The first technique uses the simultaneous excitation of multiple slices, being each plane encoded with a pre determined phase for a latter decodification of the information by the linear combination of n experiments. The second one makes use of the multislice simultaneous excitation, like the first one, but the slices are acquired in the presence of an oblique reading gradient, which provides us the multi slices signal without any further computer processing. The third technique uses frequency multiplexed excitation, that is, different slices are successively excited during the repetition time of an acquisition, making possible multislice acquisition at the same time of a single slice. The construction and the use of a phantom for the equipment characterization are discussed too. Many technical aspects necessary for an improvement of the tomography performance, like reception circuits and resonators, are discussed. A brief introduction to the gradient modulated adiabatic excitation (GMAX) technique and the first results ever obtained with it, using surface coils, is presented. (author).

  3. Pituitary disease in childhood: utility of magnetic resonance; Patologia hipofisaria en la edad pediatrica: unidad de la resonance magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Vela, A. C.; Oleaga, L.; Ibanez, A. M.; Campo, M.; Grande, D. [Hospital de Basurto. Bilbao (Spain)

    2000-07-01

    To assess the utility of magnetic resonance (MR) imaging in the study of pediatric patients with clinical suspicion of pituitary disease. We studied 18 patients aged 7 to 18 years.Fifteen had hormonal disturbances, two presented amenorrhea and 1 complained of headache, fever and symptoms of polyuria and polydipsia. All the patients were examined using a Siemens SP 42 1-Tesla MRI scanner. Sagittal and coronal T1-weighted spin-echo images were obtained; in addition T2-weighted spin-echo or fast spin-echo imaging was performed in ten cases and intravenous gadolinium was administered in nine. We found 9 patients with hypothalamic-pituitary dysgenesis, 2 with germinoma, 2 cases of pituitary hemosiderosis in patients with thalassemia, 2 cases of microadenoma, one abscess, one case of idiopathic central diabetes insipidus and one of Langerhans cell histiocytosis. MR enabled us to assess pituitary structural alterations in children with hypothalamic-pituitary hormone deficiencies. In our series of patients, hypothalamic-pituitary dysgenesiss was the most frequent cause of adenohypophyseal deficiencies, and most cases of central diabetes insipidus were secondary to masses in the sellar and suprasellar region. In patients with thalassemia, T2-weighted MR images showed the amount of iron deposited in adenophypophysis. Gadolinium-enhanced studies were useful in the study of masses and when the presence of microadenoma was suspected. (Author) 26 refs.

  4. Magnetic resonance arthrography in chronic wrist pain. Artografia con Risonanza Magnetica (arto-RM) nelle malattie dolorose croniche del polso

    Energy Technology Data Exchange (ETDEWEB)

    Valeri, G.; Ferrara, C. (Ancona Univ. (Italy). Cattedra di Radiologia); Carloni, S. (Ancona Univ. (Italy). Cattedra di Ortopedia) (and others)

    The purpose of this paper is to investigate the clinical role of Magnetic Resonance Arthrography (MRA) of the wrist in subjects with chronic pain. Thirty-five patients complaining of wrist pain for more than 6 months were submitted to MRI an MRA. All patients received and intra-articular injection of 2-10 mL of a 10 mmol saline solution of Gd-DPTA. The overall diagnostic accuracy rates of MRI and MRA were 40% and 81% respectively, with sensitivity and specificity of 63% and 39% (MRI) and of 82% and 79% (MRA). The conclusion is that compared with MRI, MRA can be considered a useful tool for the visualization of interosseus carpal ligaments and of the triangular fibrocartilage complex. MRA also helps detect injuries in these structures.

  5. Intracranial meningiomas: magnetic resonance imaging findings in 78 cases; Meningiomas intracranianos: achados de ressonancia magnetica em 78 casos

    Energy Technology Data Exchange (ETDEWEB)

    Gasparetto, Emerson L.; Leite, Claudia da Costa; Lucato, Leandro T.; Barros, Cristiano Ventorin de [University of Sao Paulo (USP), SP (Brazil). School of Medicine. Dept. of Radiology]. E-mail: egasparetto@gmail.com; Marie, Sueli K.N.; Santana, Pedro; Aguiar, Paulo Henrique Pires de [University of Sao Paulo (USP), SP (Brazil). School of Medicine. Dept. of Neurology; Rosemberg, Sergio [University of Sao Paulo (USP), SP (Brazil). School of Medicine. Dept. of Pathology

    2007-09-15

    Objective: To present the magnetic resonance (MR) imaging findings of 78 patients with meningiomas diagnosed in a single institution. Method: 78 patients with histological proven intracranial meningioma were studied. There were 52 female and 26 male patients (median=56 years). All MR imaging examinations were performed with 1.5-T MR imaging unit with standard protocol. The images were studied by two neuroradiologists, who reached the decisions regarding the findings by consensus. Results: Most of the tumors showed low signal on T1- (60%) and high signal on T2- (68%) and FLAIR (69%) weighted images. Also, the lesions showed heterogeneous signal on T1 (60%), T2 (68%) and FLAIR (64%) sequences. After contrast administration, 83% (n=65) of the tumors presented accentuated and 17% (n=13) showed moderate enhancement. The tumors were located in the frontal lobe in 44% of the cases, in the parietal lobe in 35%, the occipital lobe in 19% and the temporal lobe in 12% of the patients. Areas of vasogenic edema around the tumors were seen in 90% of the cases. Twenty six per cent of the cases showed bone infiltration, and the dural tail sign was seen in 59% of the tumors. Conclusion: Intracranial meningiomas usually show heterogeneous low signal on T1- and high signal on T2-weighted and FLAIR images, with intense enhancement after contrast administration. The frontal and parietal lobes are commonly affected. In addition, brain edema, dural tail sign and bone infiltration are the most frequent associated findings. (author)

  6. Magnetic resonance imaging in lower urinary tract endometriosis: iconographic essay; Ressonancia magnetica na endometriose do trato urinario baixo: ensaio iconografico

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Claudio Marcio Amaral de Oliveira; Coutinho, Elisa Pompeu Dias; Ribeiro, Erica Barreiros; Domingues, Marisa Nassar Aidar; Junqueira, Flavia Pegado; Coutinho Junior, Antonio Carlos [Clinicas de Diagnostico Por Imagem (CDPI) e Multi-Imagem, Rio de Janeiro, RJ (Brazil)], e-mail: cmaol@br.inter.net, e-mail: cmaolima@gmail.com

    2009-05-15

    Endometriosis is defined as the presence of functional endometrial tissue outside the endometrial cavity and myometrium. Although this is a frequent disease with multifactorial causes, involvement of the lower urinary tract is rare. Magnetic resonance imaging is highly sensitive, specific and accurate in the diagnosis of endometriosis in the lower urinary tract, especially for allowing the identification of lesions obscured by adhesions or with subperitoneal extension. The present iconographic essay presents the main magnetic resonance imaging findings of the lower urinary tract involvement by endometriosis. (author)

  7. Magnetic resonance imaging of racemous cysticercosis of the cauda equina; Ressonancia magnetica de paciente com cisticercose racemosa da cauda equina

    Energy Technology Data Exchange (ETDEWEB)

    Costa Junior, Leodante Batista da; Lemos, Sandro Pedroso [Hospital da Baleia, Belo Horizonte, MG (Brazil). Servico de Neurocirurgia; Lambertucci, Jose Roberto [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Medicina. Servico de Doencas Infecciosas e Parasitarias

    2003-12-01

    37-year-old man presented with low back pain for the last 6 months followed by sensation of numbness in the lower limbs that evolved with paraparesis, urinary retention and impotence. Subsequently, he lost control over the bowel function. Neurological examination revealed increased muscle tone along with grade zero power in both lower limbs. Knee and ankle jerks were exaggerated. Nine months prior to admission, a type II diabetes mellitus was diagnosed and he has been taking insulin ever since. MRI revealed multiple cystic lesions in the cauda equina opposite the L1-S1 vertebral bodies with no involvement of the spinal cord (Figure A: sagittal section T1-weighted image after contrast with cystic lesions on the left side - yellow arrow -, and T2-weighted image on the right - red arrows pointing cystic lesions). The cysts were hypointense on T1-weighted images (Figure B: horizontal section - yellow arrows) and hyperintense in T2-weighted images (Figure A - red arrows). Computerized tomography of the brain showed moderate ventricle dilatation (Figure C) with no intra or extra axial lesions. He was submitted to laminectomy and the cysts were surgically removed. An intense inflammatory process (arachnoiditis) involving the nerve roots of the cauda equina was reported. Histology of the surgical specimen confirmed the diagnosis of racemous cysticercosis. He improved quickly after surgery. Three months later, at the outpatient clinic, he walked with support, resumed sphincter control of the bladder and bowel and had no more pain. Ten months later he returned to hospital walking with crutches, with hypoesthesia and paraesthesia on the left leg and urinary incontinence. He refused treatment with albendazole and steroids. (author)

  8. Effect of magnetic resonance imaging on near visual acuity Efecto de la resonancia magnética sobre la agudeza visual cercana

    OpenAIRE

    José David Paulo Trujillo; Juan Carlos Vergara; Jorge Hernando Donado Gómez; Luz Marina Agudelo; Mercedes Cecilia Molina Betancur; Andrés Ignacio Arbeláez Medina; Carlos Andrés Molina Betancur

    2007-01-01

    Purpose: To determine the variation of near visual acuity, in patients exposed during short periods to intense magnetic fields in studies of magnetic resonance imaging. Methods: Descriptive study of a case series that included 40 healthy and literate individuals older than 40 years, nine of them men, submitted to a procedure of head and neck magnetic resonance imaging; all of them had near visual acuity better than 20/200 without glasses, and were not under the effects of ansiolytic medicatio...

  9. Stochasticity of the energy absorption in the electron cyclotron resonance; Estocasticidad de la absorcion de energia en la resonancia electron-ciclotronica

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C. [Departamento de Fisica, ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Hernandez A, O

    1998-07-01

    The energy absorption mechanism in cyclotron resonance of the electrons is a present problem, since it could be considered from the stochastic point of view or this related with a non-homogeneous but periodical of plasma spatial structure. In this work using the Bogoliubov average method for a multi periodical system in presence of resonances, the drift equations were obtained in presence of a RF field for the case of electron cyclotron resonance until first order terms with respect to inverse of its cyclotron frequency. The absorbed energy equation is obtained on part of electrons in a simple model and by drift method. It is showed the stochastic character of the energy absorption. (Author)

  10. Spectroscopy study of electron spin resonance of coal oxidation of different rank; Estudio por espectroscopia de resonancia espin electron de la oxidacion de carbones de diferente rango

    Energy Technology Data Exchange (ETDEWEB)

    Enciso Prieto, Hector Manuel

    1992-07-01

    The present work constitutes an initial step for the knowledge of the coal oxidation, with the purpose of preventing the adverse influences caused by this phenomenon in the physical-chemical characteristics and in the tendency to the spontaneous combustion. Since the knowledge the influence of the free radicals in this process, their relative concentration was measured by means of the use of the technique of resonance spin electron. This technique measures the absorption of electromagnetic radiation, generally in the microwaves region, for the materials that not have electrons matched up in a strong magnetic field. In the essays of oxidation three coal of different range and different characteristics of mass were used and it was studied the influence of the temperature, particle size and the range. The results showed that the coal of Guacheta (bituminous low in volatile) it presents bigger concentration of free radicals, after the reaction with the atmospheric oxygen, with regard to the coal of the Cerrejon (bituminous high in volatile B) and Amaga (bituminous high in volatile C). Although this doesn't indicate that the coal of Guacheta is that more easily is oxidized, but rather it possibly presents stabilization of radicals for resonance. It concluded that there are differences in the oxidation mechanism between coal of different rank and different agglomeration properties.

  11. Bases neuroanatómicas y neurofuncionales del trastorno de atención en la esquizofrenia: estudio mediante resonancia magnética.

    OpenAIRE

    Salgado Pineda, Pilar

    2003-01-01

    La esquizofrenia es un grave trastorno mental que afecta al 1% de la población, sin que exista un único síntoma o signo que la defina. En ella se ve afectada la capacidad de pensamiento creativo e imaginativo, la habilidad social, el uso coherente del lenguaje e incluso la vivencia de varias emociones. Las alteraciones neuropsicológicas más frecuentemente referidas en la esquizofrenia son: memoria, fluencia verbal, funciones ejecutivas y sobretodo, atención, algunos autores han hipotetizado ...

  12. Experiencia con el uso de la resonancia magnética intraoperatoria de bajo campo en neurocirugía para el tratamiento de neoplasias cerebrales

    OpenAIRE

    Roldán Ramos, Pedro

    2016-01-01

    La evolución de la cirugía guiada por imágenes, constituye el ejemplo notorio del desarrollo mostrado por la Neurocirugía en las últimas décadas. Tras la introducción del microscopio quirúrgico a la cirugía, pocos han sido los avances tan rentables para la salud del paciente neuroquirúrgico en términos de grados de resección tumoral y morbilidad postquirúrgica. La neuronavegación solventó, en parte, los inconvenientes inherentes a la cirugía convencional y permitió la planificación de unas cr...

  13. Diagnóstico. Estudio radiológico. Ecografía, tomografía computarizada y resonancia magnética

    Directory of Open Access Journals (Sweden)

    Francisco Javier Gallo Vallejo

    2014-01-01

    El aspecto de la seguridad del paciente debe ser tenido en cuenta, intentando proteger al paciente de excesivas radiaciones ionizantes, mediante repeticiones innecesarias de radiografías o proyecciones inadecuadas, o por solicitud de pruebas como TC, cuando no están indicadas.

  14. Estética de la resonancia. (una mirada a la obra de vassily kandinski desde una óptica deleuzeana

    Directory of Open Access Journals (Sweden)

    Juan Carlos Romo

    2016-01-01

    Full Text Available El presente texto aborda la obra pictórica de Vasily Kandinski y la estrecha relación que esta tiene con la música. El análisis que se hace de la obra de Kandinski tiene como punto de referencia la reflexión estética de la filosofía de Gilles Deleuze. Figuras conceptuales como devenir, inmanencia y acontecimiento son la base de este estudio; con ellas se pretende un acercamiento crítico a la obra del pintor ruso con miras a su interpretación.

  15. Application of the Electron paramagnetic resonance to the ionizing radiation dosimetry; Aplicacion de la Resonancia paramagnetica electronica a la dosimetria de las radiaciones ionizantes

    Energy Technology Data Exchange (ETDEWEB)

    Urena N, F. [Instituto Nacional de Investigaciones Nucleares, Km. 36.5 Carretera Mexico-Toluca, 52045 Salazar, Estado de Mexico (Mexico)

    2000-07-01

    The Electron Paramagnetic Resonance (EPR) is defined as the resonant absorption of electromagnetic energy in paramagnetic substances by the spin transition of a non-pairing electron between different energy levels in presence of a magnetic field. (Slighter, 1989). One of the more important characteristic of EPR is that the electron spin levels are subdivided by the electron interaction with the magnetic dipoles of the nearby nucleus giving occasion for a spectral structure called hyperfine structure. In this kind of interactions two limit cases are distinguished: 1. when the non-pairing electron is located in a central ion surrounded of atoms belonging to coordinate molecules. 2. When a non-pairing electron interactioning in the same form with a number of equivalent nucleus, which is common in organic radicals, these will give as result spectra. Some EPR spectrometer can be used to dosimetric purposes by free radicals via. In this work, it is presented the application of EPR to dosimetry of ionizing radiations by free radicals via which allows to determinations of high doses. (Author)

  16. Gclust Server: 150241 [Gclust Server

    Lifescience Database Archive (English)

    Full Text Available 150241 SCE_YPL192C=PRM3 Cluster Sequences - 133 Pheromone-regulated protein required for karyoga...e annotation Pheromone-regulated protein required for karyogamy Number of Sequenc

  17. Magnetic resonance imaging findings in patients with Hallervorden-Spatz syndrome; Achados de ressonancia magnetica na sindrome de Hallervorden-Spatz

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Cesar Higa; Lima, Eduardo Carneiro; Cerri, Giovanni Guido; Leite, Claudia da Costa [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Dept. de Radiologia; Rosemberg, Sergio [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Dept. de Patologia

    2003-12-01

    The objective of this study was to review the magnetic resonance imaging findings in patients with Hallervorden-Spatz syndrome. We evaluated eight patients with Hallervorden-Spatz syndrome using magnetic resonance imaging. The protocol included at least sagittal and axial T1-weighted images and axial and coronal T2-weighted images. Intravenous gadolinium was administered in a dose of 0.1 mmol/kg. Post-enhanced images were obtained at least in the axial and coronal planes. The results were: all patients presented a bilateral and symmetrical 'tiger-eye signal' on T2-weighted images, corresponding to central hyperintensity and peripheral hypointensity in the globi pallidus. FLAIR and diffusion images showed similar abnormalities. There was no gadolinium enhancement in any of the cases. We concluded that magnetic resonance imaging findings in patients with Hallervorden-Spatz syndrome are very typical and allow the diagnosis of the disease. (author)

  18. Nano-magnetite coated with gold: alternative oncological therapy with magnetic hyperthermia; Nanomagnetita recubierta de oro: terapia oncologica alternativa con hipertermia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Cordova F, T.; Jimenez G, O.; Basurto I, G. [Universidad de Guanajuato, Campus Leon, Division de Ciencias e Ingenierias, Loma del Bosque 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Martinez E, J. C., E-mail: theo@fisica.ugto.mx [IPN, Unidad Profesional Interdisciplinaria de Ingenieria Campus Guanajuato, Av. Mineral de Valenciana 200, Industrial Puerto Interior, 36275 Silao de la Victoria, Guanajuato (Mexico)

    2017-10-15

    Localized hyperthermia performed through the use of nanoparticles is one of the most promising procedures for the cancer treatment. In this work, the synthesis of magnetite nanoparticles (Fe{sub 2}O{sub 3}) was carried out using the thermal decomposition method. Subsequently, these nanoparticles were coated with gold and suspended in aqueous phase. As a result, nanoparticles capable of being heated by the application of an alternating magnetic field or through the use of infrared radiation were obtained. As an additional feature, these nanoparticles are biocompatible thanks to their golden coating. The synthesized nanoparticles can be functionalized by the conjugation of a molecule (aptamer, antibody, peptide, etc.) whose target is a cancer cell in order to adhere to it the nanoparticle-marker complex, to subsequently carry out a heating with the objective of induce cell death. In conclusion, the synthesized nanoparticles allow providing an alternative treatment for cancer through the use of localized hyperthermia, either using magnetic or infrared heating. (Author)

  19. Preparation of microspheres containing methyl methacrylate (MMA) with magnetic nanoparticles; Preparacao de microesferas contendo metacrilato de metila (PMMA) com nanoparticulas magneticas

    Energy Technology Data Exchange (ETDEWEB)

    Feuser, P.E.; Souza, M.N. de, E-mail: paulofeuser@hotmail.co, E-mail: nele@eq.ufrj.b [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Engenharia Quimica

    2010-07-01

    Magnetic nanoparticles have found many technological applications and has been intensively studied due to its special magnetic properties. In most biomedical applications, microspheres containing magnetic nanoparticles is used as a vehicle for transporting drugs, presenting several advantages when compared to other conventional methods. PMMA is a polymer which has biocompatibility and can be used for the encapsulation of magnetic nanoparticles, showing a great degree of saturation magnetization. PMMA microparticles containing magnetic nanoparticles were prepared by suspension polymerization. Polymers containing magnetic nanoparticles were characterized by X-ray diffraction (XRD), vibrating sample magnetization, thermogravimetric analysis, optical microscopy, chromatography gel permeation, analysis of particle size - malversizer 2000 (Malvern Instruments). The average size of magnetic nanoparticles was approximately 150 {mu}m and depending on the amount of magnetic nanoparticles in the reaction medium Mw of microspheres can be altered. (author)

  20. Leukokoria in childhood: differential diagnosis using ultrasonography, computed tomography, and magnetic resonance imaging; Leucocoria na infancia: diagnostico diferencial por ultra-sonografia, tomografia computadorizada e ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Montandon Junior, Marcelo Eustaquio; Montandon, Cristiano [Colegio Brasileiro de Radiologia e Diagnostico por Imagem (CBR), Sao Paulo, SP (Brazil)]. E-mail: marmontandon@hotmail.com; Figueiredo, Sizenildo da Silva; Ribeiro, Flavia Aparecida de Souza; Nobrega, Bruno Barcelos da; Lobo, Leonardo Valadares Barbosa; Teixeira, Kim-Ir-Sen Santos [Goias Univ., Goiania (Brazil). Hospital das Clinicas. Servico de Diagnostico por Imagem e Anatomia Patologica; Jacob, Beatriz Mahmud [Goias Univ., Goiania (Brazil). Faculdade de Medicina. Radiologia e Diagnostico por Imagem

    2004-04-01

    Leukokoria is an abnormal pupillary reflex most commonly seen in children that usually results from an intra-ocular abnormality. The evaluation of a child with leukokoria should be performed particularly to rule out a retinoblastoma (the cause of leukokoria in half of the cases). The authors present the main clinical and imaging features for the diagnosis of the most common causes of leukokoria. (author)

  1. Magnetic resonance imaging of the hip in rheumatoid arthritis patients: a descriptive study; A ressonancia magnetica do quadril na avaliacao de pacientes com artrite reumatoide: estudo descritivo

    Energy Technology Data Exchange (ETDEWEB)

    Caldana, Wanda Chiyoko Iwakami; Fernandes, Artur da Rocha Correa [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: wiwakami@ig.com.br; Ciconelli, Rozana Mesquita [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil); Juliano, Yara [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Epidemiologia e Bioestatistica

    2005-07-15

    Objective: To assess the usefulness of MRI as a diagnostic method in patients with rheumatoid arthritis, and to evaluate the frequency of changes in the hip in symptomatic and asymptomatic patients. Materials and methods: Forty patients (17 symptomatic and 23 asymptomatic) were evaluated by 1.5 T magnetic resonance imaging (MRI) after intravenous contrast media injection. MRI findings were divided in inflammatory, degenerative, combined (inflammatory and degenerative) and extra-articular changes. Results: The most frequent findings seen were degenerative and extra-articular changes (22.5% each). Inflammatory changes were seen in only five (12.5%) symptomatic patients, four of them with degenerative findings associated (10%). Conclusion: The use of MRI of the hip allowed the evaluation of the main articular abnormalities seen in patients with rheumatoid arthritis. The most frequent findings were degenerative and extra-articular changes. Inflammatory findings were seen in only five patients, four of them with degenerative changes associated. (author)

  2. Magnetic resonance imaging pre- and postoperative evaluation of tetralogy of Fallot; Avaliacao pre e pos-operatoria da tetralogia de Fallot por ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Bernardes, Renata Junqueira Moll; Simoes, Luiz Carlos [Instituto Nacional de Cardiologia (INC), Rio de Janeiro, RJ (Brazil). Servico de Cardiologia da Crianca e do Adolescente; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia]. E-mail: edmarchiori@bol.com.br; Bernardes, Paulo Manuel de Barros; Gonzaga, Maria Beatriz Albano Monzo [Rede Labs/D' Or, Rio de Janeiro, RJ (Brazil)

    2004-08-01

    The purpose of this study was to assess the usefulness of magnetic resonance imaging (MRI) in the pre- and postoperative evaluation of patients with tetralogy of Fallot. Twenty patients aged 1 to 29 years were prospectively evaluated with black-blood and contrast-enhanced angiographic techniques, 11 with the classic form of tetralogy of Fallot and 9 with tetralogy of Fallot and pulmonary atresia. MRI studies provided adequate visualization of the aorta that was classified as dilated or not dilated, and definition of its position in all cases. The use of contrast-enhanced MR angiographic techniques provided excellent imaging of the main right and left pulmonary arteries. The results suggest that MRI, including contrast-enhanced angiography techniques, is a useful tool in the evaluation of patients with tetralogy of Fallot before and after cardiac surgery since it provides important anatomical information that is not always obtained with echocardiography. MRI can be considered an alternative to cardiac catheterization, particularly in the evaluation of the pulmonary vascular anatomy. (author)

  3. Proceedings of the 10. Brazilian meeting on magnetic resonance. Abstracts and program; Anais da 10. Jornada brasileira de ressonancia magnetica. Resumos e programa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This annual meeting, held in Brazil from August 4 - 8, 2008 comprised: one mini-course about the use of nuclear magnetic resonance for structural chemical analyses); four major conferences ('NMR applied to molecular dynamics studies of solids and semi-solids', 'Beyond genomes: assessing protein function using solution NMR', 'NMR applied to natural products', 'Solid-state NMR as a tool for the investigation of membrane-associated peptides and proteins'), four short conferences ('NMR applied to petroleum, derivatives and biofuels', 'NMR of solids applied to pharmaceutical drugs', 'NMR applied to agricultural and cattle raising quality control', 'NMR applied to oil wells logging'); oral presentations of three undergrad, three M.Sc., and three Ph.D. projects; nine other research works presented as oral communications and fifty two as congress panels/posters), most being carried out by scientific groups from various Brazilian R and D institutions. Prizes to nine remarkable works of undergrad and post-grad students have been awarded, and a General Assembly meeting of AUREMN, the Brazilian Association of Nuclear Magnetic Resonance Users, also took place at the end of the event. Main topics of the research works presented at this meeting, both as oral communications and as congress panels, were thus distributed: 24% in chemical sciences (mainly organic chemistry), 45% in applied life sciences (agricultural and food sciences, biological sciences and medicine), 29% in materials science (including petroleum and alternative fuels), and 2% regarding development of equipment accessories and improvement of instrumental techniques.

  4. Temporomandibular joint - normal features and disc displacements: magnetic resonance imaging; Articulacao temporomandibular - aspectos normais e deslocamentos de disco: imagem por ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Ana Carolina Araujo; Sarmento, Viviane Almeida; Campos, Paulo Sergio Flores; Gonzalez, Maria Olivia Dias [Bahia Univ., Salvador, BA (Brazil). Faculdade de Odontologia]. E-mail: ana_carolinaramos@hotmail.com

    2004-12-01

    Disc displacement of the temporomandibular joint has been defined as an abnormal relationship between the articular disc and the mandibular condyle, fossa and articular eminence. Disc displacements may occur without immediate interference in the function of the joint. Magnetic resonance imaging shows high diagnostic accuracy in the determination of articular disc position and has been indicated as the diagnostic method of choice for soft tissue abnormalities of the temporomandibular joint. The aim of this study is to review the literature including the normal features and different types of disc displacement of the temporomandibular joint as well as the imaging findings, emphasizing the role of magnetic resonance imaging. (author)

  5. Magnetic resonance imaging of sella turcica: evaluation of patients with galactorrhea, amenorrhea and hyperprolactinemia; Ressonancia magnetica da sela turca: avaliacao de pacientes com galactorreia, amenorreia e hiperprolactinemia

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Alair Augusto Sarmet M.D. dos [Hospital Universitario Antonio Pedro, Niteroi, RJ (Brazil). Dept. de Radiologia; Moreira, Denise Madeira [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia; Andreiuolo, Pedro Angelo [Beneficencia Portuguesa de Niteroi, RJ (Brazil). Servico de Radiologia Santa Cruz Scan

    1999-08-01

    We have selected 135 cases of patients who have done magnetic resonance imaging of sella region, carried out from September, 1991 to August, 1996, who had galactorrhea (G), amenorrhea(A), and hyperprolactinemia (H), isolated or in association. The patients were divided in seven groups, according to the presence of these symptoms and signs. All examinations were made in a private clinic in the city of Rio de Janeiro, Brazil. Correlating these patients with the results of the magnetic resonance images, we found 57 micro adenomas, 31 normal examinations, 22 macro adenomas, 11 pituitary hyperplasias, 7 empty sella and 7 cases included in other aspects. The micro adenoma predominated in groups 1 (GAH), 2 (GH), 3 (HA) and 5 (H), that is, in all groups whose patients had hyperprolactinemia. In macro adenomas, a bright signal on T 1-weighted images indicates pituitary apoplexy with intratumoral hemorrhage. All in all, the magnetic resonance imaging is excellent method to be used in the evaluation of patients with changes in the hypothalamic-pituitary axis. (author)

  6. Corpus callosum dysgenesis and lipoma: embryologic and magnetic resonance imaging aspects; Disgenesia do corpo caloso e lipoma: consideracoes embriologicas basicas e aspectos de imagem a ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Abreu Junior, Luiz de; Borri, Maria Lucia; Wolosker, Angela Maria Borri; Hartmann, Luiz Guilherme de Carvalho; Galvao Filho, Mario de Melo [Hospital e Maternidade Sao Luiz, Sao Paulo, SP (Brazil). Setor de Diagnostico por Imagem]. E-mail: abreujr@directnet.com.br; D' Ippolito, Giuseppe [Hospital e Maternidade Sao Luiz, Sao Paulo, SP (Brazil). Setor de US/TC/RMN

    2005-07-15

    The corpus callosum is the major system of association fibers that permits communication of both cerebral hemispheres. Magnetic resonance imaging has improved the study of brain malformations, including the corpus callosum dysgenesis. Lipoma is a common finding in the spectrum of corpus callosum dysgenesis. The purpose of these study was to review the embryologic events and the magnetic resonance imaging aspects related to the corpus callosum dysgenesis and to the formation of the related lipoma. (author)

  7. High speed magnetically levitated transport systems: Technical and economic aspects. Sistemi di trasporto ad alta velocita' a levitazione magnetica: Considerazioni tecniche ed economiche

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, G; Morini, A [Padua Univ. (Italy)

    1992-11-01

    In assessing the current state of technology relative to high speed (400 to 500 km/h) magnetically levitated (MAGLEV) transportation systems, this paper compares the technical aspects of the two main types of suspension systems now being developed specifically for these transportation systems, i.e., attractive electromagnetic using conventional magnets, and repulsive electrodynamic using superconducting magnets. Commercialization prospects for these systems are reviewed by analyzing areas where high speed levitated trains could compete against conventional rail and air transportation systems. The technology review includes progress reports on research and developments activities taking place in Germany and Japan, as well as, descriptions of some recent applications of this technology.

  8. Bone injuries in the post-traumatic knee: evaluation by magnetic resonance imaging; Comprometimento osseo do joelho pos-trauma: avaliacao pela ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    De Grossi, Carla Martins [Universidade Federal, Rio de Janeiro, RJ (Brazil). Curso de Pos-graduacao em Radiologia; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Servico de Radiologia; Santos, Alair Augusto S.M.D. dos [Hospital Santa Cruz, Niteroi, RJ (Brazil). Servico de Radiologia]. E-mail: edmarchiori@zipmail.com.br

    2001-06-01

    This paper presents the results of 50 patients with trauma of the knee submitted to magnetic resonance imaging in the period of January 1996 to December 1997. The appearance and incidence of the main bone lesions were evaluated and correlated with the mechanisms of aggression and with clinical data. Associated lesions were also evaluated. Bone contusions were the most commonly findings encountered and were observed in 38 patients (76%). Osteochondral fractures occurred in five patients (10%) and bone fractures were detected in five patients (10%), of which two were associated with contusions in other adjoining bone compartments. Chondromalacia of the patella was observed only in two patients (4%). We concluded that magnetic resonance imaging is the imaging method of choice for the diagnosis of bone lesions in patients with trauma of the knee. (author)

  9. Magnetic resonance imaging textural evaluation of posterior cranial fossa tumors in childhood; Avaliacao textural por ressonancia magnetica dos tumores da fossa posterior em criancas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Joelson Alves dos; Costa, Maria Olivia Rodrigues da; Otaduy, Maria Concepcion Garcia; Lacerda, Maria Teresa Carvalho de; Leite, Claudia da Costa [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Dept. de Radiologia]. E-mail: joelson_alves@ig.com.br; Matsushita, Hamilton [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Dept. de Neurologia

    2004-08-01

    Objective: To distinguish healthy from pathological tissues in pediatric patients with posterior cranial fossa tumors using calculated textural parameters from magnetic resonance images. Materials And Methods: We evaluated 14 pediatric patients with posterior cranial fossa tumors using the software MaZda to define the texture parameters in selected regions of interest representing healthy and pathological tissues based on T2-weighted magnetic resonance images. Results: There was a statistically significant difference between normal and tumoral tissues as well as between supposedly normal tissues adjacent and distant from the tumoral lesion. Conclusion: Magnetic resonance textural evaluation is an useful tool for determining differences among various tissues, including tissues that appear apparently normal on visual analysis. (author)

  10. Evaluation of poly(vinylpyrrolidone) and collagen by Low Field Nuclear Magnetic Resonance Spectroscopy; Avaliacao da polivinilpirrolidona e do colageno por ressonancia magnetica nuclear de baixo campo

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Paula de M.; Tavares, Maria I.B. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano]. E-mail: pmcosta@ima.ufrj.br

    2005-07-01

    Blends of natural and synthetic polymers represent a new class of materials with better mechanical properties and biocompatibility than those of the single components. Collagen and poly(vinylpyrrolidone) are well known for their important biological properties. The blending of collagen with poly(vinylpyrrolidone) makes it possible to obtain new materials in which strong interactions between the synthetic and biological components occur. Do to the excellent biocompatibility of these polymers, this blend has been much studied intending biomedical applications. And a one technique that can provide important information on molecular mobility, compatibility and even evaluate the interactions that can occur with these polymers is the Low Field Nuclear Magnetic Resonance Spectroscopy. Thus, the purpose of this work is to evaluate collagen and poly(vinylpyrrolidone) by Low Field Nuclear Magnetic Resonance Spectroscopy. From the values of relaxation times obtained, we can conclude that these materials have different interactions, and different mobility domains, confirming the heterogeneity and complexity of these materials. (author)

  11. Dosimetry for computed tomography using Fricke gel dosimetry and magnetic resonance imaging; Dosimetria em tomografia computadorizada empregando dosimetro Fricke gel e a tecnica de imageamento por ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Capeleti, Felipe Favaro; Campos, Leticia L., E-mail: felipe@gmpbrasil.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-04-15

    In this work it was determined a new method for the determination of absorbed doses in Computed Tomography (CT) examinations using Fricke gel dosimetry developed at IPEN. Absorbed doses were determined by different methods of analysis, such as optical absorption spectrometry, ionization chambers and magnetic resonance imaging. Lower limit of sensitivity of the Fricke gel solution, the solution repeatability signal Fricke gel and CT equipment, detection sensitivity, among other tests were performed. Different equipment of computed tomography with multiple detectors were used. The Fricke gel solution showed better repeatability than ±5.5% using the technique of optical absorption spectrophotometry and computed tomography equipment showed repeatability better than ±0.2%. The Fricke gel solution features an easy and relatively quick preparation, but it is necessary to be careful not to contaminate and lose the solution. With the results, it was confirmed the application of this type of dosimetry for computed tomography equipment. (author)

  12. 12. Brazilian meeting on magnetic resonance; mini-course in NMR. Abstracts and program; 12. Jornada brasileira de ressonancia magnetica; mini-curso em RMN

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Theoretical and experimental papers are presented in these proceedings comprehending the following subjects: nuclear magnetic resonance, organic and non organic compounds, polymers, petroleum, physical chemistry, chemical structures, molecular biology, molecular structures and proteins.

  13. Dosimetric evaluation in mammary glands radiotherapy using expansive prosthesis with magnetic valve; Avaliacao dosimetrica de tratamentos de radioterapia de mama usando proteses expansivas com valvula magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Lizar, J.C.; Pavoni, J.F.; Baffa, O. [Universidade de Sao Paulo (USP), Ribeirao Preto (Brazil); Krutman, Y. [Rabin Medical Center (RMC), (Israel)

    2016-07-01

    This work aims to verify the influence on dose distribution that the expansive prosthesis (SILIMED/470), containing a magnetic valve, generates in radiotherapy postoperative treatment of patients who have undergone mastectomy. (author)

  14. Use of nuclear magnetic resonance in the characterization of modified clays; Uso da ressonancia magnetica nuclear na caracterizacao de argilas modificadas

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Sidnei Q.M. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Menezes, Sonia M.C. de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Gil, Rosane A.S. San [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica

    1992-12-31

    This work uses NMR spectroscopy with rotation in the {sup 29} Si, {sup 27} Al and {sup 23} Na magic angles for characterization of clays with Si/Al ratio in the range 3.0 - 16,5, obtained by chemical treatment of commercial samples, under different conditions of leaching with mineral acid 5 refs., 2 figs., 2 tabs.

  15. Proceedings of the 4. Meeting of the nuclear magnetic resonance users; Anais do 4. Encontro de usuarios de ressonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    This book shows the papers presented in the 4. Meeting of Nuclear Magnetic Resonance Users which took place in Rio de Janeiro, Brazil, 1993. The main topics discussed were: solid state NMR; structural and conformational structure determination by NMR; perspectives for NMR in Brazil; recent achievements in NMR

  16. Determination of the composition of a mixture of polar substances by NMR; Determinacao da composicao de uma mistura de substancias polares por espectrometria de ressonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Antonio C.F.; Silva, Antonio J.R. da [Universidade Federal, Rio de Janeiro (Brazil). Nucleo de Pesquisas de Produtos Naturais

    1994-12-31

    This work describes the process of analysis of a mixture of polar compounds obtained from the extract of Phyllanthus tennellus, a plant known in Brazil as `quebra-pedra`, which is extensively used in Brazilian popular medicine. The methodology, which includes the use of chromatography and NMR, is described. The proposed composition of the mixture is presented. A discussion is presented concerning one component which could not be identified

  17. Use of the image by nuclear magnetic resonance (nucleography) in obstetrical aspects. Part 2. Emprego da imagem por ressonancia magnetica nuclear (nucleografia) em obstetricia. Parte 2

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    Lacreta, O [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina

    1987-10-01

    In the first part of this paper the author presented the physical principles on magnetic resonance imaging. The author describes now the obstetrical aspects of nucleography, showing how the maternal and the fetal organs are depicted. The clinical significance of the images is presented. (author).

  18. Use of the image by nuclear magnetic resonance (nucleography) in obstetrical aspects. Part 1. Emprego da imagem por ressonancia magnetica nuclear (nucleografia) em obstetricia. Parte 1

    Energy Technology Data Exchange (ETDEWEB)

    Lacreta, O [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina

    1987-09-01

    Nuclear magnetic resonance (nucleography) is a new method to study human body. In this paper the physical principles on nuclear magnetic resonance and its applications to the pregnant women are presented. (author).

  19. Magnetic resonance imaging identification of muscular and ligamentous structures of the female pelvic floor; Identificacao das estruturas musculo-ligamentares do assoalho pelvico feminino na ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra, Maria Rita Lima; Soares, Adriano Fleury F.; Faintuch, Salomao; Goldman, Suzan Menasce; Ajzen, Sergio A.; D' Ippolito, Giuseppe; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), Sao Paulo, SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: mrcfc@ig.com.br; Girao, Manoel [Universidade Federal de Sao Paulo (UNIFESP/EPM), Sao Paulo, SP (Brazil). Dept. de Ginecologia

    2001-12-01

    The objective was to determine the frequency and to assess the interobserver agreement of identification of muscular and ligamentous pelvic floor structures using magnetic resonance imaging. The method: twenty asymptomatic female volunteers (aged 20-80 years old; mean: 50) were submitted to magnetic resonance imaging (1.5 T) examinations of the pelvis. Turbo spin-echo sequences were employed to obtain T1 and T2 weighted images on axial and sagittal planes. Two independent observers evaluated the scans in order to identify the levator ani (coccygeal, pubococcygeal, iliococcygeal and puborectalis muscles), obturatorius internus and urethral sphincter muscles, and the pubovesical and pubourethral ligaments. The frequency and the interobserver agreement of the identification of the anatomical structures were assessed (kappa statistic - {kappa}). The results: the frequency of identification of the structures ranged from 50 to 100%, and was slightly lower for identification of the ligaments. Interobserver agreement was as follows: levator ani and obturatorius internus muscle ({kappa}=1), pubococcygeal ({kappa}=0.62), iliococcygeal ({kappa}=0.86), puborectalis ({kappa}= 0.27), coccygeal ({kappa}=0) and urethral sphincter muscles ({kappa}=1), pubovesical ({kappa}=0.50) and pubourethral ({kappa}=0.58) ligaments. The conclusion: magnetic resonance imaging of the pelvis allowed precise identification of the main muscular and ligamentous pelvic floor structures in most individuals, whereas interobserver agreement was considered good. (author)

  20. Parenchymal abnormalities in cerebral venous thrombosis: findings of magnetic resonance imaging and magnetic resonance angiography; Alteracoes parenquimatosas na trombose venosa cerebral: aspectos da ressonancia magnetica e da angiorressonancia

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Clecia Santos; Pellini, Marcos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia]. E-mail: csferreira@superig.com.br; Boasquevisque, Edson [Universidade do Estado do Rio de Janeiro, (UERJ), RJ (Brazil). Faculdade de Medicina. Dept. de Patologia; Souza, Luis Alberto M. de [Hospital da Beneficencia Portuguesa do Rio de Janeiro, RJ (Brazil). Servico de Imagem. Setor de Ressonancia Magnetica

    2006-09-15

    Objective: to determine the frequency and localization of parenchymal abnormalities in cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography as well as their correlation with the territory and affected venous drainage. Materials and methods: retrospective analysis (1996 to 2004) of 21 patients (3 male and 18 female) age range between 3 and 82 years (mean 40 years, median 36 years) with clinical and radiological diagnosis of cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography in 2D PC, 3D PC and contrast-enhanced 3D TOF sequences. The statistical analysis was performed with the qui-square test. Four patients had follow-up exams and three patients underwent digital subtraction angiography. Results: main predisposing factors were: infection, use of oral contraceptives, hormone replacement therapy and collagenosis. Predominant symptoms included: focal deficit, headache, alteration of consciousness level and seizures. Most frequent parenchymal manifestations were: cortical/subcortical edema or infarct, venous congestion and collateral circulation, meningeal enhancement and thalamic and basal ganglia edema or infarct. Occlusion occurred mainly in superior sagittal, left transverse, left sigmoid and straight sinuses. Cavernous sinus and cortical veins thrombosis are uncommon events. Conclusion: cerebral venous thrombosis is an uncommon cause of stroke, with favorable prognosis because of its reversibility. Diagnosis is highly dependent on the radiologist capacity to recognize the presentations of this disease, principally in cases where the diagnosis is suggested by parenchymal abnormalities rather than necessarily by visualization of the thrombus itself. An accurate and rapid diagnosis allows an immediate treatment, reducing the morbidity and mortality rates. (author)

  1. Pathologic conditions in pregnancy; Preliminary evaluation of MR efficacy. Condizioni patologiche nella gravidanza; Valutazioni preliminari sull'efficacia della Risonanza Magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Beomonte Zobel, B; Tella, S; Innacoli, M; D' Archivio, C; Cardone, G; Masciocchi, C; Gallucci, M; Passariello, R [L' Aquila Univ. (Italy). Cattedra di Radiologia; Cappa, F [L' Aquila Univ. (Italy). Clinica Ostetrica-Ginecologica

    1991-01-01

    Soma authors suggested that MR imaging could rapresent an effective diagnostic alternative in the study of pathologic conditions of mother and fetus during pregnancy. To verify the actual role of MR imaging, we examined 20 patients in the 2nd and 3rd trimester of gestation, after a preliminary US examination. Fifteen patients presented fetal or placental pathologies; in 4 patients the onset of the pathologic condition occurred during pregnancy; in 1 case of US diagnosis of fetal ascites, MR findings were nornal and the newborn was healty. As for placental pathologies, our series included a case of placental cyst, two hematomas between placenta and uterine wall, and two cases of partial placenta previa. As for fetal malformation, we evaluated a case of omphalocele, one of Prune-Belly syndrome, a case of femoral asimmetry, one of thanatophoric dwarfism, a case of thoracopagus twins with cardiovascular abnormalities, two fetal hydrocephali, and three cases of pyelo-ureteral stenosis. As for maternal pathologies during pregnancy, we observed a case of subserous uterine fibromyoma, one of of right hydronephrosis, one of protrusion of lumbar invertebral disk, and a large ovarian cyst. In our experience, MR imaging exhibited high sensitivity and a large field of view, which were both useful in the investigation of the different conditions occurring during pregnancy. In the evaluation of fetal and placental abnormalities, especially during the 3rd trimester, the diagnostic yieldof MR imaging suggested it as a complementary technique to US for the evaluation of fetal malformation and of intrauterine growth retardation.

  2. Magnetic resonance imaging of the liver in postpartum stable women with HELLP syndrome; Ressonancia magnetica hepatica em puerperas estaveis com sindrome HELLP

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ana Rita Marinho Ribeiro; Amorim, Melania Maria Ramos de; Katz, Leila; Souza, Alex Sandro Rolland de; Santos, Aleksana Regina Viana Dutra; Lima, Ana Luiza Medeiros Vasconcelos de [Instituto Materno Infantil Prof. Fernando Figueira, Recife, PE (Brazil). Centro de Atencao a Mulher. Unidade de Terapia Intensiva Obstetrica

    2008-09-15

    Objectives: To describe magnetic resonance (MR) findings in the liver of stable patients with HELLP syndrome in the puerperium. Methods: A descriptive study was carried out from August 2005 to July 2006, involving a series of 40 postpartum patients admitted to an obstetric intensive therapy unit in IMIP (Instituto Materno Infantil Prof. Fernando Figueira) with diagnosis of HELLP syndrome (complete and partial). Complete HELLP syndrome was defined when all laboratory parameters were present and incomplete when one or more but not all laboratory findings were present. All patients had stable clinical conditions and were evaluated with magnetic resonance of the liver and the main findings were recorded. Results. Average maternal age was 26.8 {+-} 6.4 years and gestational age at delivery was 34 {+-} 26.8 weeks. The MR imaging was performed between eight and 96 hours after diagnosis of HELLP syndrome (56 {+-} 31h). The most frequent findings were ascitis in 20% (n = 8), pleural effusion in 17.5% and hepatic steatosis in 7.5%. The periportal intensity signal was normal in all cases. Cases of liver infarction and sub-capsular or parenchymatous hematoma were not observed. Conclusion: Findings of magnetic resonance imaging of the liver in stable HELLP syndrome postpartum patients were few and unspecific. Severe liver injuries such as parenchymatous or sub-capsular hematoma, entailing life risk were not found. Results do not corroborate the use of magnetic resonance as routine examination for stable patients with HELLP syndrome. (author)

  3. Iron oxide nanoparticles for use in contrast agents in magnetic resonance imaging; Nanoparticulas de oxido de ferro para uso como agentes de contraste em imagens por ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Elisa M.N. de; Rocha, Maximiliano S. da; Caimi, Priscila de A.; Basso, Nara R. de S.; Zanini, Mara L.; Papaleo, Ricardo M., E-mail: elisa.oliveira@acad.pucrs.br [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil)

    2015-07-01

    In this work were carried out synthesis of iron oxide nanoparticles coated with dextran, comparing the results of using different concentrations of dextran, iron salts, temperature and reaction time. The compounds were analyzed by DLS, XRD, TGA, TEM, FTIR, Zeta Potential and relaxivity. Nanoparticles with dispersion around 10-15 nm and average hydrodynamic diameters of 16-50 nm, with superparamagnetic behavior were obtained. The ratio of the relaxivities (r2/r1) in aqueous solutions was 5.30, close to value of the commercially available iron oxide contrast agents. (author)

  4. Alzheimer's disease and magnetic resonance spectroscopy of the hippocampus; Doenca de Alzheimer e espectroscopia por ressonancia magnetica do hipocampo

    Energy Technology Data Exchange (ETDEWEB)

    Engelhardt, Eliasz; Moreira, Denise M. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Neurologia Deolindo Couto; Laks, Jerson; Marinho, Valeska M.; Rozenthal, Marcia [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Psiquiatria; Oliveira Junior, Amarino C. [Hospital ProCardiaco, Rio de Janeiro, RJ (Brazil). Setor de Radiologia

    2001-12-01

    Objective: acquisition of data of magnetic resonance metabolite spectrum of the hippocampal formation (hippocampus-hc) in the elderly, normal and with Alzheimer's disease (AD). Method: Subjects matched for age: a. normal sample (n=20), CDR=0, and b. AD sample (n=40), CDR 1 and 2. Technique: Signa Horizon LX-GE, 1.5T, {sup 1}H-MRS with automated software PROBE/SV, VOI: hc (right and left); single voxel (2x2x2cm); TR 1500ms/TE 50ms; PRESS; metabolites: N-acetylaspartate (Naa), choline (Cho), creatine (Cr), myo-inositol (mI). Results: The present data relate to the ratios of Naa, Cho and mI, with Cr taken as reference, and the mI/Naa ratio. The study showed reduction of Naa, increase of mI and of the mI/Naa ratio, and not consistent results for Cho. The results of the whole sample of AD patients compared to the pooled normal mean {+-} sd were significant for Naa, mI and mI/Naa (p<0.01). Accuracy in relation to the individual values of both samples showed satisfactory levels of sensitivity, specificity and positive predictive value. Conclusion: The present results can be used as a helpful tool to detect pathologic changes of the hippocampus in AD, and allowing greater accuracy and an earlier diagnosis of this disease. (author)

  5. Automatic storing of single gamma spectra on magnetic tape. Programs LONGO, DIRE; Automatizacion del almacenamiento en cinta magnetica de espectros gamma directos. Programas LONGO, DIRE

    Energy Technology Data Exchange (ETDEWEB)

    Los Arcos Merino, J M

    1978-07-01

    The program LONGO provides the block size and the block number in a binary file on magnetic tape. It has been applied to analyse the structure of the nine-track magnetic tapes storing single or coincidence gamma spectra files, recorded in octet form by a MULTI-8 minicomputer in the Nuclear Spectrometry Laboratory of J.E.N. Then the program DIRE has been written to transform the single gamma spectra into a new FASTRAND disk file, storing the information in-36 bit words. A copy of this file is obtained on magnetic tape and the single gamma spectra are then available by standard FORTRAN V reading sentences. (Author) 3 refs.

  6. Value of magnetic resonance imaging in prenatal diagnosis of placental accretism; Valor da ressonancia magnetica no diagnostico antenatal do acretismo placentario

    Energy Technology Data Exchange (ETDEWEB)

    Francisco, Viviane Vieira; Goldman, Suzan Menasce; Faria, Juliano; Szejnfeld, Jacob [Universidade Federal de Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostico por Imagem]. E-mail: vieira_francisco@uol.com.br

    2006-12-15

    Purpose: to establish the main signs of placental accretism in magnetic resonance imaging (MRI) in patients with clinical suspicion and to estimate the benefit of this method. Methods: prospective transversal study with 15 patients suspected of placental accretism, referred between March 2003 and February 2006. Gestational age varied from 20 to 31 weeks. All patients underwent MRI to study the placenta and had previously done an ultrasonography. Material was sent to histological study. MRI was done on Magnetom Impact and Sonata Maestro Class Siemens{sup R}, with acquired sequences HASTE, TURBO SPIN in axial, sagittal, coronal planes and echo gradient (GE{sup R}), pre- and post-dynamic contrast in the best plan for acquisition. Images were analyzed by a team of two radiologists. Results: mean gestational age was 24.3 weeks. We studied seven placenta previa (47%), six anterior placentas (40%) and two posterior placentas (13%). Ultrasonography was positive in 80% of the placentas and MRI in 53%. However, echography had a low concordance with anatomic pathological studies by Kappa test (11%), revealing 75% of sensitivity, 14% of specificity, 50% as positive predictive value (PPV) and 33% as negative predictive value (NPV). MRI had an excellent concordance with anatomic pathological studies (0.86), showing 100% of sensitivity, 86% of specificity, 89% as PPV and 100% as NPV. Conclusions: MRI is useful for placental accretism diagnosis. The principal findings are transmural hyper-signal, the loss of continuity in myometrial wall in fast sequences and the identification of vessels invading myometrial layer in dynamic sequences. (author)

  7. MR imaging in the diagnosis of the os trigonum syndrome; Il ruolo della Risonanza Magnetica nella diagnosi della sindrome dell'os trigonum

    Energy Technology Data Exchange (ETDEWEB)

    Tamburrini, O.; Porpiglia, H.; Barresi, D.; Bertucci, B.; Console, D. [Catanzaro Univ. Magna Grecia, Catanzaro (Italy). Radiologia, Dipt. di Medicina Sperimentale e Clinica

    1999-12-01

    In this paper is investigated the yield of Magnetic Resonance Imaging (MRI) in hind foot conditions, particularly the os trigonum syndrome, which are very difficult to diagnose clinically. 7 consecutive patients were examined. They were complaining of hind foot pain for more than 4 months (male:female=1:6; age range 16-22 years, average 18.6). Three patients practiced competitive sports and 4 ballet. It was performed conventional radiography (orthogonal projections) and then MRI with a 0.5 T superconductive unit with surface coils; MR images were acquired with T1-weighted spin-echo (SE), T2-weighted gradient-echo (GRE), and fast inversion recovery (FIR) fat-suppressed sequences with 4 mm thickness and 0 mm gap. In 2 cases the os trigonum had irregular margins with subchondral sclerosis and widened synchondrosis. In 3 patients it was found flessor hallucis longus tenosynovitis, likely caused by tendon compression and displacement within its sheath; there were neither os trigonum marrow edema nor synchondrosis widening. One patient had os trigonum hypertrophy, mild synchondrosis widening and marrow edema, in the os trigonum and the posterior aspect of talus. One patient had the os trigonum, but no signs referable to the os trigonum syndrome. In the posterior impingement syndrome, the objective is to show inflammatory changes in the posterior capsule of the ankle joint, adjacent ligaments, tendons and chondrosynovial surface. MR provides important information on soft tissues involvement, synovial reaction, chondral and subchondral bone injuries and the association of flexor hallucis longus synovitis, if present. MRI also yields detailed information for correct therapeutic approach. In conclusion, MRI appears to be the technique of choice, after conventional radiography, thanks to its non invasiveness, multi planarity, and high spatial and contrast resolution. [Italian] Scopo di questo lavoro e' quello di sottolineare il determinante contributo informativo della RM nell'ambito delle malattie dolorose del retropiede e piu' in particolare nella sindrome dell'os trigonum, in considerazione della notevole difficolta' clinica per la corretta diagnosi. Lo studio e' stato condotto su sette pazienti che lamentavano dolore al retropiede da piu' di quattro mesi (maschi/femmine=1/6), con eta' compresa tra 16 e 22 anni (eta' media 18,6 anni); 3/7 praticavano attivita' agonistica sportiva, 4/7 danza classica. In 2/7 pazienti l'os trigonum presentava margini irregolari con sclerosi subcondrale e ampliamento della sincondrosi. In 3/7 pazienti e' stata documentata tenosinovite del tendine flessore lungo dell'alluce causata verosimilmente dalla sua compressione e spostamento all'interno della propria guaina, senza ne' alterazione dell'intensita' di segnale dell'os trigonum, ne' ampliamento della sincondrosi. In 1/7 pazienti sono stati rilevati ipertrofia dell'os trigonum, modico ampliamento della sincondrosi e segni importanti di edema midollare nell'os trigonum e nel processo posteriore dell'astragalo. In 1/7 pazienti, pur in presenza di os trigonum rilevato all'esame radiologico tradizionale, l'esame RM non ha documentato alcuno dei segni da riferire a sindrome dell'os trigonum: la diagnosi definitiva e' stata tendinite achillea. La RM e' l'unica metodica che fornisce importanti informazioni sul coinvolgimento dei tessuti molli, della superficie condro-ossea e sulle reazioni sinoviali riuscendo percio' a dimostrare chiaramente l'eventuale coesistente tenosinovite del tendine flessore lungo dell'alluce ed inoltre provvedendo a fornire informazioni dettagliate per il corretto approccio terapeutico. In conclusione, nell'ambito delle malattie dolorose del retropiede da cause ossee, laddove si sospetti clinicamente la sindrome dell'os trigonum, la non invasivita' della RM, unitamente alle sue panoramicita', risoluzione spaziale e risoluzione di contrasto, ne fanno metodica d'elezione, dopo l'esame radiologico tradizionale.

  8. Brain MRI in 17 patients with ocular Behcet`s disease; Risonanza Magnetica dell`encefalo in 17 pazienti affetti da malattia di Behcet oculare

    Energy Technology Data Exchange (ETDEWEB)

    Accorinti, Massimo; Pivetti Pezzi, Paola [Rome, Univ. (Italy). Istituto di Oftalmologia; Di Biasi, Claudio; Trasimeni, Guido; Melone, Antonio; Gualdi, Gianfranco [Rome, Univ. (Italy). Unita` TC-RM I Clinica Medica

    1997-04-01

    Behcet`s disease is a chronic relapsing disorder of unknown etiology characterized by oral aphthous ulcerations, uveitis, genital ulcerations and bone lesions. A variety of other signs including polyarthritis, vascular conditions (blood vessel occlusions and aneurysms), epididymitis, gastrointestinal, pulmonary and heart lesions may also occur. Central nervous system (CNS) involvement is reported in 10-49 % of cases and it is the first symptom of the disease in 5 % of subjects. The neuro-Behcet`s syndrome may appear as a brainstem syndrome, and an organic confusional syndrome or dementia. cranial hypertension, mostly related to cerebral venus thrombosis, is also present in neuro-Behcet`s disease and its incidence is reported in up to 10 % of Behcet`s patients. MRI is reportedly the most sensitive neuroradiological approach to detect the focal lesions related to neuro-Behcet disease and several single cases or series of Behcet`s patients with neurologic sings have been examined with MRI. They used MRI to investigate CNS involvement in Behcet`s disease patients with and without previous neurologic sings. MRI was carried out on 17 patients with ocular Behcet`s disease without neurological symptoms to assess the possible subclinical involvement of the CNS. PD and T2-weighted hypersignal foci were demonstrated in parietal, frontal, subcortical and periventricular white matter in 6 subjects. Neuroradiological abnormalities were found only in patients with complete disease and with the disease diagnosed more than 10 years earlier. Even though the pathogenesis of these neuroradiological abnormalities and their correlation with Behcet`s disease remain to be clarified, their study suggests the possibility of subclinical CNS involvement in these patients, which may affect the therapeutic approach and their prognosis.

  9. Characterization of steel grit recovered from ornamental rocks waste by magnetic separation; Caracterizacao da granalha de aco recuperada do residuo de rochas ornamentais por separacao magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Junca, E.; Telles, V.B.; Rodrigues, G.F.; Oliveira, J.R. de; Tenorio, J.A.S., E-mail: eduardojunca@gmail.co [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia Metalurgica e de Materiais; Instituto Federal de Ciencia e Tecnologia do Espirito Santo (IFES), Vitoria, ES (Brazil)

    2010-07-01

    The aim of this work is characterization of steel grit recovered from ornamental rock waste by magnetic separation. The magnetic separation was realized in three steps: first, using a high intensity wet magnetic separator, which used only the remaining magnetic field of equipment. In the second step, the magnetic material obtained in the first phase was subjected to a new manual magnetic separation using rare earth magnets. In a third step, magnetic material obtained with rare earth magnets was subjected to manual magnetic separation using ferrite magnets. After the magnetic separation, the material was sent to characterization which was obtained by chemical analysis, scanning electron microscopy, X-ray diffraction and size analysis. The size analysis showed that the concentrate range from 0,5 to 563,67 {mu}m with 4 wt.% over 100 {mu}m and content metallic iron of 93 wt%. (author)

  10. Ovarian granulocytic sarcoma: a case report and magnetic resonance imaging findings; Sarcoma granulocitico no ovario: relato de caso e achados na ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Licia Pacheco [Hospital Geral de Fortaleza (HGF), CE (Brazil). Servico de Diagnostico por Imagem], e-mail: licia_p@hotmail.com; Silveira, Claudio Regis Sampaio [Hospital Geral de Fortaleza (HGF), CE (Brazil). Servico de Radiologia; Costa, Fabricio da Silva [Universidade Estadual do Ceara (UECE), CE (Brazil); Monte, Hipolito [Hospital Monte Klinikum, Fortaleza, CE (Brazil)

    2008-12-15

    Granulocytic sarcoma (chloroma) is a tumor consisting of myeloid precursors in an extramedullary site. It is complication of both acute and chronic myelogenous leukemias. Although the lesion can occur at any site, ovarian involvement is rare. We report a case of ovary tumor associated with acute myeloid leukaemia and its imaging appearance on magnetic resonance. (author)

  11. Enhancing the sensitivity of Dengue virus serotype detection by RT-PCR among infected children in India.

    Science.gov (United States)

    Ahamed, Syed Fazil; Vivek, Rosario; Kotabagi, Shalini; Nayak, Kaustuv; Chandele, Anmol; Kaja, Murali-Krishna; Shet, Anita

    2017-06-01

    Dengue surveillance relies on reverse transcription-polymerase chain reaction (RT-PCR), for confirmation of dengue virus (DENV) serotypes. We compared efficacies of published and modified primer sets targeting envelope (Env) and capsid-premembrane (C-prM) genes for detection of circulating DENV serotypes in southern India. Acute samples from children with clinically-diagnosed dengue were used for RT-PCR testing. All samples were also subjected to dengue serology (NS1 antigen and anti-dengue-IgM/IgG rapid immunochromatographic assay). Nested RT-PCR was performed on viral RNA using three methods targeting 654bp C-prM, 511bp C-prM and 641bp Env regions, respectively. RT-PCR-positive samples were validated by population sequencing. Among 171 children with suspected dengue, 121 were dengue serology-positive and 50 were dengue serology-negative. Among 121 serology-positives, RT-PCR detected 91 (75.2%) by CprM654, 72 (59.5%) by CprM511, and 74 (61.1%) by Env641. Among 50 serology-negatives, 10 (20.0%) were detected by CprM654, 12 (24.0%) by CprM511, and 11 (22.0%) by Env641. Overall detection rate using three methods sequentially was 82.6% (100/121) among serology-positive and 40.0% (20/50) among serology-negative samples; 6.6% (8/120) had co-infection with multiple DENV serotypes. We conclude that detection of acute dengue was enhanced by a modified RT-PCR method targeting the 654bp C-prM region, and further improved by using all three methods sequentially. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Expression of CGRP in the temporomandibular joint; Expresion de CGRP en la articulacion temporomandibular

    Energy Technology Data Exchange (ETDEWEB)

    Caviedes Bucheli, Javier [Pontificia Universidad Javeriana, Facultad de Odontologia, Bogota, D.C. (Colombia); Medina Buitrago, Diana Marcela [Pontificia Universidad Javeriana, Bogota, D.C. (Colombia)

    2002-07-01

    degeneracion osea es clasificada entre leve, moderada y severa, de acuerdo con hallazgos de resonancia nuclear magnetica. Las 15 muestras de tejido retrodiscal hiperplasico son tomadas de las pacientes sometidas a cirugia abierta de articulacion temporomandibular. Los especimenes fueron colocados en bloques plasticos con medio congelante y son almacenados a -70 grados centigrados hasta la extraccion del neuropeptido por radioinmunoensayo con el estuche para el CGRP. Una relacion directamente proporcional es establecida entre el grado de degeneracion osea y expresion del neuropeptido y entre la clasificacion de osteoartrosis con la escala visual analoga. Los hallazgos han mostrado correlacion definitiva entre niveles de dolor y expresion del neuropeptido. El CGRP es expresado en el tejido retrodiscal de articulacion temporomandibular en humanos con enfermedad degenerativa articular y es relacionado directamente con niveles de osteoartrosis y dolor.

  13. Imágenes Neuro–Oftalmológicas

    Directory of Open Access Journals (Sweden)

    C. Gonzalo Rojas, Ing.

    2010-11-01

    Mediante resonancia magnética funcional es posible localizar las áreas elocuentes cerebrales (resonancia magnética funcional convencional o representar la conexión funcional de un área cerebral específica (resonancia magnética resting state.

  14. Intracellular labeling and quantification process by magnetic resonance imaging using iron oxide magnetic nanoparticles in rat C6 glioma cell line; Marcacao intracelular e processo de quantificacao por imagem por ressonancia magnetica utilizando nanoparticulas magneticas de oxido de ferro em celulas da linhagem C6 de glioma de rato

    Energy Technology Data Exchange (ETDEWEB)

    Mamani, Javier Bustamante; Pavon, Lorena Favaro; Sibov, Tatiana Tais; Rossan, Fabiana; Silveira, Paulo Henrique; Cardenas, Walter Humberto; Gamarra, Lionel Fernel, E-mail: javierbm@einstein.br [Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Miyaki, Liza Aya Mabuchi [Faculdade de Enfermagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Amaro Junior, Edson [Departamento de Diagnostico por Imagem e Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil)

    2012-04-15

    Objective: To assess intracellular labeling and quantification by magnetic resonance imaging using iron oxide magnetic nanoparticles coated with biocompatible materials in rat C6 glioma cells in vitro. These methods will provide direction for future trials of tumor induction in vivo as well as possible magnetic hyperthermia applications. Methods: Aminosilane, dextran, polyvinyl alcohol, and starch-coated magnetic nanoparticles were used in the qualitative assessment of C6 cell labeling via light microscopy. The influence of the transfection agent poly-L-lysine on cellular uptake was examined. The quantification process was performed by relaxometry analysis in T{sub 1} and T{sub 2} weighted phantom images. Results: Light microscopy revealed that the aminosilane-coated magnetic nanoparticles alone or complexed with poly-L-lysine showed higher cellular uptake than did the uncoated magnetic particles. The relaxactivities of the aminosilane-coated magnetic nanoparticles with a hydrodynamic diameter of 50nm to a 3-T field were r{sub 1}=(6.1 +- 0.3) x10{sup -5} ms{sup -1}mL/{mu}g, r{sub 2}=(5.3 +- 0.1) x 10{sup -4} ms{sup -1}mL/{mu}g, with a ratio of r{sub 2} / r{sub 1}{approx_equal} 9. The iron uptake in the cells was calculated by analyzing the relaxation rates (R{sub 1}and R{sub 2}) using a mathematical relationship. Conclusions: C6 glioma cells have a high uptake efficiency for aminosilane-coated magnetic nanoparticles complexed with the transfection agent poly-L-lysine. The large ratio r{sub 2} / r{sub 1}{approx_equal} 9 indicates that these magnetic nanoparticles are ideal for quantification by magnetic resonance imaging with T{sub 2}-weighted imaging techniques. (author)

  15. Measurement of resonances in {sup 12} C + {sup 4} He through inverse kinematics with thick targets; Medicion de resonancias en {sup 12} C + {sup 4} He mediante cinematica inversa con blancos gruesos

    Energy Technology Data Exchange (ETDEWEB)

    Aguilera, E.F.; Lizcano, D.; Martinez Q, E.; Fernandez, M.C.; Murillo, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Goldberg, V. [Cyclotron Institute, Texas A and M University, College Station, TX 77843 (United States); Skorodumov, B.B.; Rogachev, G. [Physics Department, University of Notre Dame, IN 46556 (United States)

    2003-07-01

    The excitation function of elastic scattering for the system {sup 12} C + {sup 4} He to energy from 0.5 to 3.5 MeV in the center of mass system (c.m.) was measured. We use a gassy thick target and the technique of inverse kinematics which allows to make measurements at 180 degrees in c.m. Using the R matrix theory those was deduced parameters of the resonances and the results were compared with measurements reported in the literature made with other techniques. (Author)

  16. Aplicación clínica de las imágenes de resonancia potenciadas en difusión y tractografía en un niño con holoprosencefalia

    Directory of Open Access Journals (Sweden)

    Blair Ortiz

    2011-03-01

    Presentamos un paciente con holoprosencefalia semilobar en quien la imagen potenciada en difusión y la tractografía demostró falla de la inducción ventral del prosencéfalo y fusión anormal de varios fascículos de la sustancia blanca en el cerebro y en el tallo encefálico. De esta forma, las anormalidades de los fascículos de la sustancia blanca en casos de holoprosencefalia se pueden identificar por medio de las imágenes potenciadas en difusión y tractografía fasciculografía.

  17. MRI and endoscopic ultrasonography in the staging of gastric cancer Resonancia magnética y ecoendoscopia para el estadiaje del cáncer gástrico

    Directory of Open Access Journals (Sweden)

    M. G. Arocena

    2006-08-01

    Full Text Available Objective: to determine the diagnostic precision of endoscopic ultrasounds (EUS and magnetic resonance imaging (MRI in the preoperative staging of gastric cancer. Methods: a prospective, blind study was carried out in 17 patients diagnosed with gastric cancer (GC using endoscopic biopsy from November 2002 to June 2003. Patients underwent preoperative MRI and EUS. The reference test used was pathology, and laparotomy for non-resectable cases. Results: MRI (53% was better than EUS in the assessment of gastric wall infiltration (35%. MRI (50% was also superior to EUS (42% for N staging. After pooling stages T1-T2 and T3-T4 together, results improved for both MRI (67 and 87.5%, respectively and EUS (67 and 62.5%, respectively (p < 0.05. N staging -lymph node invasion- results were correct in 50% for MRI as compared to EUS (42%. In classifying positive and negative lymph nodes EUS was superior to MRI (73 versus 54%. Conclusions: MRI was the best method in the assessment of gastric wall infiltration. EUS was superior to MRI for T1 staging, and in the assessment of lymph node infiltration.

  18. Angioplastia primaria optimizada: comparación de tres estrategias de administración de ABCIXIMAB intracoronario y sus efectos sobre el tamaño del infarto valorado mediante resonancia magnética cardíaca

    OpenAIRE

    Santos González, Belén

    2016-01-01

    Se ha demostrado ampliamente que el intervencionismo coronario percutáneo (ICP), cuando está disponible de forma inmediata, es el tratamiento de elección del Síndrome Coronario Agudo con elevación del segmento ST (SCACEST). Existe suficiente evidencia para afirmar que la angioplastia primaria es superior a la trombolisis intravenosa consiguiendo un mayor grado de permeabilidad de la arteria, reduciendo el riesgo de reoclusión y de reinfarto. Todos estos efectos se traducen en mejora de la sup...

  19. Comparison Between the Trajectories of Electric Field Resonances and those of Rational Surfaces in TJ-II; Comparacion entre las Trayectorias Correspondientes a Resonancias del Campo Electrico y las de Superficies Racionales en el TJ-II

    Energy Technology Data Exchange (ETDEWEB)

    Guasp, J.; Liniers, M. [Ciemat. Madrid (Spain)

    2000-07-01

    Both the radial electric field resonance case and the corresponding to rational magnetic surfaces, show a number of similar behaviours: a) Strong sensitivity of the passing particle loss fraction, and mainly of their los times, to lower order rational values of the ratio between the poloidal and toroidal rotation angular velocities. b) In both cases there exist similar simple analytical models that allow qualitative predictions for the phase space regions where resonant effects can be expected. c) Strong similitude of trajectories, as well in the Poincare diagrams as in the angular maps. Near the resonant regions a extreme minimization of the radial excursion appears, and both diagrams present a minimum filling. At both sides of these regions there are wide excursions, directed alternatively towards the inner and the outer parts of the plasma. Far from these resonant zones the diagrams filling comes back to be continuous. d) All these behaviours are more marked, and the topology change more sudden, the lower is the periodicity order of the resonance, and are extremely clear for the 1/3 and 1/2 cases. This wealth of similar behaviour suggests a single origin for all these phenomena, linked with the trajectory topology, that will be the subject of a specific study. (Author) 13 refs.

  20. Measure of the uncertainty associated with the reconstruction of applicators in adaptive guided brachytherapy by resonance; Medida de la incertidumbre asociada a la reconstruccion de aplicadores en braquiterapia adaptativa guiada por resonancia

    Energy Technology Data Exchange (ETDEWEB)

    Torres Pozas, S.; Federico, M.; Perez Molina, J. L.; Marti Asenjo, J.; Sanchez Carrascal, M.; Macias verde, D.; Ruiz Egea, E.; Lara Jimenez, P.; Martin Oliva, R.

    2013-07-01

    The objective of this study is to assess the uncertainty introduced in the process to rebuild the catheters using three methods, manual reconstruction from a template elaborate service, auto-rebuild with the software included in the TPS and reconstruction from radiopaque mannequins in CT and subsequent merger. (Author)

  1. Powderspec, a program for the efficient simulation of spectra of electron paramagnetic resonance of powders with orthorhombic symmetry; Powderspec, un programa para la simulacion eficiente de espectros de resonancia paramagnetica electronica de polvos con simetria ortorrombica

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez T, L.; Beltran L, V

    1991-09-15

    In this report a FORTRAN source program which simulates the second order powder pattern and spectrum of electron paramagnetic resonance (EPR) in crystal fields with orthorhombic symmetry using Gauss-Legendre quadratures is given. Also the commentaries which describe each step in detail are presented. (Author)

  2. Electronic paramagnetic resonance in the Mn In X (X:Te,S) diluted magnetic semiconductor system; Resonancia paramagnetica electronica en el sistema semiconductor magnetico diluido Cd Mn In X (X:Te,S)

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, Bernardo; Betancourt, Luis; Sagredo, Vicente [Universidad de los Andes, Merida (Venezuela). Dept. de Fisica; Alcala, Rafael [Zaragoza Univ. (Spain). Dept. de Fisica de la Materia Condensada

    1997-12-31

    Semiconductor compounds wit the II-III-VI stoichiometry are very interesting materials since they present very good semiconducting characteristics and, along with strong magnetic properties, these II Mn In VI compounds have a great potential as opt and magneto-electronic devices. Among the possible magnetic properties of the materials is the presence of the spin-glass phase. Electron paramagnetic resonance is one of the techniques used to confirm this phase. The chosen crystals were chosen by chemical vapor transport. The absorption lines of these two families with 0.1 x 1 were all Lorentzian in shape and centred at g=2. A large broadening of the resonance line width was observed when lowering the temperature to below 80 K. This behaviour was fitted to the known existing models, and good values of the calculated parameters were obtained (author). 18 refs., 2 figs., 2 tabs.

  3. Estudio clínico y de resonancia magnética orientado al conocimiento del sustrato patológico de la discapacidad en la esclerosis múltiple primariamente progresiva

    OpenAIRE

    Tur Gómez, Carmen

    2015-01-01

    Con el objetivo de contribuir al estudio de los mecanismos que subyacen al aumento de la discapacidad en la esclerosis múltiple primariamente progresiva (EMPP), fijamos tres objetivos principales. Asimismo, nos propusimos hacer una revisión de la literatura sobre EMPP publicada hasta el momento actual, utilizando la web www.pubmed.com como herramienta de trabajo, que sirviera como introducción a los estudios de la tesis. El primer objetivo consistió en investigar el grado de correlación entre...

  4. La influencia de los mecanismos reguladores de las emociones en la toma de decisión de compra en mujeres: un estudio con resonancia magnética funcional por imagen (fMRI)

    OpenAIRE

    Murgich López, Valeria

    2016-01-01

    Hasta hace pocas décadas, las emociones eran vistas como factores de perturbación en el proceso de toma de decisión. Su presencia en dicho proceso se solía asociar más a una ‘perturbación’ que a una constante, cuya implicación pasa de ser anecdótica, a jugar un importante y potente papel, como un factor de influencia en la toma de una decisión. Esta reciente visión ha sido el producto del trabajo de diferentes investigadores, cuya labor ha revelado, gracias, entre otros aspectos al uso de la ...

  5. Study of the presence of free radicals formed in tumors, using the electronic paramagnetic resonance spectroscopy method; Estudiar la presencia de radicales libres formados en tumores, usando el metodo de espectroscopia de resonancia paramagnetica electronica (RPE)

    Energy Technology Data Exchange (ETDEWEB)

    Chonchon, Y [Instituto Venezolano de Investigaciones Cientificas (IVIC). Centro de Estudios Avanzados (CEA). Postgrado en Fisica Medica, Altos de Pipe (Venezuela); Silva, P [Instituto Venezolano de Investigaciones Cientificas (IVIC). Centro de Fisica. Laboratorio de la Materia Condensada, Altos de Pipe (Venezuela); Gutt, F [Instituto Venezolano de Investigaciones Cientificas (IVIC). Centro Tecnologico. Unidad de Tecnologia Nuclear. Laboratorio Secundario de Calibracion Dosimetrica, Altos de Pipe (Venezuela); Almeida, C de [Universidade do Estado do Rio de Janeiro (UERJ). Laboratorio de Ciencias Radiologicas (LCR), Rio de Janeiro (Brazil)

    2001-07-01

    It studies molecules and ions in order to provide a structural and dynamic system information, establishing comparisons among different stadiums of the same tumor and/or different tumors, as well as the relationship among the behaviors of healthy tissues and carcinogenic tissues. [Spanish] Estudia moleculas e iones con electrones desapareados a fin de proporcionar una informacion estructural y dinamica del sistema, estableciendo comparaciones entre los distintos estadios de un mismo tumos y/o diferentes tumores, asi como la relacion entre los comportamientos de tejidos sanos y tejido cancerigeno.

  6. Estadiaje local del carcinoma rectal: imágenes de ecografía versus resonancia magnética. Revisión sistemática de la literatura y metaanálisis.

    Science.gov (United States)

    Guenaga, Katia F; Otoch, Jose P; Artifon, Everson L A

    2016-01-01

    New surgical techniques in the treatment of rectal cancer have improved survival mainly by reducing local recurrences. A preoperative staging method is required to accurately identify tumor stage and planning the appropriate treatment. MRI and ERUS are currently being used for the local staging (T stage). In this review, the accuracy of MRI and ERUS with rigid probe was compared against the gold standard of the pathological findings in the resection specimens. Five studies met the inclusion criteria and were included in this meta-analysis. The accuracy was 91.0% to ERUS and 86.8% to MRI (p=0.27). The result has no statistical significance but with pronounced heterogeneity between the included trials as well as other published reviews. We can conclude that there is a clear need for good quality, larger scale and prospective studies.

  7. Studies on magnetocaloric and magnetic coupling effects =

    Science.gov (United States)

    Amaral, Joao Cunha de Sequeira

    O presente trabalho apresenta novas metodologias desenvolvidas para a analise das propriedades magneticas e magnetocaloricas de materiais, sustentadas em consideracoes teoricas a partir de modelos, nomeadamente a teoria de transicoes de fase de Landau, o modelo de campo medio molecular e a teoria de fenomeno critico. Sao propostos novos metodos de escala, permitindo a interpretacao de dados de magnetizacao de materiais numa perspectiva de campo medio molecular ou teoria de fenomeno critico. E apresentado um metodo de estimar a magnetizacao espontanea de um material ferromagnetico a partir de relacoes entropia/magnetizacao estabelecidas pelo modelo de campo medio molecular. A termodinamica das transicoes de fase magneticas de primeira ordem e estudada usando a teoria de Landau e de campo medio molecular (modelo de Bean-Rodbell), avaliando os efeitos de fenomenos fora de equilibrio e de condicoes de mistura de fase em estimativas do efeito magnetocalorico a partir de medidas magneticas. Efeitos de desordem, interpretados como uma distribuicao na interaccao magnetica entre ioes, estabelecem os efeitos de distribuicoes quimicas/estruturais nas propriedades magneticas e magnetocaloricas de materiais com transicoes de fase de segunda e de primeira ordem. O uso das metodologias apresentadas na interpretacao das propriedades magneticas de variados materiais ferromagneticos permitiu obter: 1) uma analise quantitativa da variacao de spin por iao Gadolinio devido a transicao estrutural do composto Gd5Si2Ge2, 2) a descricao da configuracao de cluster magnetico de ioes Mn na fase ferromagnetica em manganites da familia La-Sr e La-Ca, 3) a determinacao dos expoentes criticos β e δ do Niquel por metodos de escala, 4) a descricao do efeito da pressao nas propriedades magneticas e magnetocaloricas do composto LaFe11.5Si1.5 atraves do modelo de Bean-Rodbell, 5) uma estimativa da desordem em manganites ferromagneticas com transicoes de segunda e primeira ordem, 6) uma descricao de

  8. Gamma-ray spectrometry, electrical resistivity, and magnetic susceptibility of agricultural soils in the Northwest region of the Parana State, Brazil; Gamaespectrometria, resistividade eletrica e susceptibilidade magnetica de solos agricolas no noroeste do estado do Parana

    Energy Technology Data Exchange (ETDEWEB)

    Becegato, Valter Antonio [Universidade do Estado de Santa Catarina-UDESC, Centro de Ciencias Agroveterinarias, Lages, SC (Brazil); Ferreira, Francisco Jose Fonseca, E-mail: becegato@cav.udesc.br, E-mail: francisco.ferreira@ufpr.br [Universidade Federal do Parana (LPGA/UFPR), Curitiba, PR (Brazil). Dept. de Geologia. Lab. de Pesquisas em Geofisica Aplicada

    2005-10-15

    Gamma-ray spectrometry, electrical resistivity, and magnetic susceptibility measurements were taken from agricultural areas near the City of Maringa, in the Northwest region of the Parana state, south Brazil, in order to characterize the spatial distribution of radionuclides (K, eU, and eTh), the apparent resistivity, and the magnetic susceptibility determined for soils. Three different types of soils are present in this agricultural area: Alfisoil, clayey texture Oxisoil, both deriving from Lower Cretaceous basalts of the Serra Geral Formation; and medium texture Oxisoil from reworked Serra Geral and Goio-Ere formations, the latter deriving from sandstones of the Upper Cretaceous Caiua Group. It could be observed that in more clayey soils both concentration of radionuclides and susceptibility values are higher than in more sandy soils, especially due to the higher adsorption in the former and to the higher availability of magnetic minerals in the latter. The average ppm and Bq Kg{sup -1} grades for K, eU, and eTh in the areas under anthropic activity are of 1766-54.75, 0.83-10.22, and 1.78-7.27, respectively. These grades are significantly higher than those of non-occupied or non-fertilized areas (1101-34.15 K, 0.14-1.69 eU, and 1.31-5.36 eTh in ppm and Bq Kg-1, respectively.) Correlations were observed between uranium and clay, uranium and magnetic susceptibility, uranium and organic matter, and between electric resistivity and clay grades. Varied concentrations of radionuclides were also observed in different fertilizer formulations applied to soy and wheat cultures. Apparent electric resistivity values between 25 and 647 Ohm.m and magnetic susceptibility values between 0.28 e 1.10 x 10-3 SI due to clay and magnetic minerals represented important soil discrimination factors in the study area that can be incorporated as easy, low-cost soil mapping tools. (author)

  9. Surgical neuro navigator guided by preoperative magnetic resonance images, based on a magnetic position sensor;Neuronavegador cirurgico guiado por imagens de ressonancia magnetica pre-operatoria, baseado num transdutor de posicao magnetico

    Energy Technology Data Exchange (ETDEWEB)

    Perini, Ana Paula; Siqueira, Rogerio Bulha; Carneiro, Antonio Adilton Oliveira, E-mail: adilton@ffclrp.usp.b [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica; Oliveira, Lucas Ferrari de [Universidade Federal de Pelotas (UFPel), RS (Brazil). Dept. de Informatica; Machado, Helio Rubens [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Dept. de Neurocirurgia

    2009-08-15

    Image guided neurosurgery enables the neurosurgeon to navigate inside the patient's brain using pre-operative images as a guide and a tracking system, during a surgery. Following a calibration procedure, three-dimensional position and orientation of surgical instruments may be transmitted to computer. The spatial information is used to access a region of interest, in the pre-operative images, displaying them to the neurosurgeon during the surgical procedure. However, when a craniotomy is involved and the lesion is removed, movements of brain tissue can be a significant source of error in these conventional navigation systems. The architecture implemented in this work intends the development of a system to surgical planning and orientation guided by ultrasound image. For surgical orientation, the software developed allows the extraction of slices from the volume of the magnetic resonance images (MRI) with orientation supplied by a magnetic position sensor (Polhemus{sup R}). The slices extracted with this software are important because they show the cerebral area that the neurosurgeon is observing during the surgery, and besides they can be correlated with the intra-operative ultrasound images to detect and to correct the deformation of brain tissue during the surgery. Also, a tool for per-operative navigation was developed, providing three orthogonal planes through the image volume. In the methodology used for the software implementation, the Python{sup tm} programming language and the Visualization Toolkit (VTK) graphics library were used. The program to extract slices of the MRI volume allowed the application of transformations in the volume, using coordinates supplied by the position sensor. (author)

  10. Structural and magnetic Ni-Zn ferrite synthesized by combustion reaction and sintered in a conventional oven; Caracterizacao estrutural e magnetica de ferrita Ni-Zn sintetizadas por reacao de combustao e sinterizadas em forno convencional

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, D.A.; Diniz, V.C.S.; Costa, A.C.F.M., E-mail: deboralbq@hotmail.com [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Departamento de Engenharia de Materiais; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia de Materiais; Cornejo, D.R. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Fisica. Departamento de Fisica dos Materiais e Mecanica

    2011-07-01

    The Ni-Zn ferrite due to their electrical and magnetic properties allows use in various technological applications. These properties can be controlled through appropriate choice of chemical composition, structural characteristics and morphology of the powders used and the techniques used for sintering. Thus, this study aims to evaluate the sintering in a conventional oven at a temperature of 1200 deg C/2h samples of Ni-Zn ferrite synthesized by microwave energy. The samples were characterized by density measurement, XRD, SEM and magnetic measurements. The results indicate the phase formation of Ni-Zn ferrite crystalline phase with crystallite size of 80 nm. The sample was heterogeneous microstructure with grain size of about 1 μm high intergranular porosity. The sample showed the saturation magnetization of 7.57 emu/g, coercive field and remanent magnetization close to zero, thus indicating a behavior characteristic of superparamagnetic materials. (author)

  11. Clinical recommendations of cardiac magnetic resonance, Part I: ischemic and valvular heart disease: a position paper of the working group 'Applicazioni della Risonanza Magnetica' of the Italian Society of Cardiology.

    Science.gov (United States)

    Aquaro, Giovanni Donato; Di Bella, Gianluca; Castelletti, Silvia; Maestrini, Viviana; Festa, Pierluigi; Ait-Ali, Lamia; Masci, Pier Giorgio; Monti, Lorenzo; di Giovine, Gabriella; De Lazzari, Manuel; Cipriani, Alberto; Guaricci, Andrea I; Dellegrottaglie, Santo; Pepe, Alessia; Marra, Martina Perazzolo; Pontone, Gianluca

    2017-04-01

    Cardiac magnetic resonance (CMR) has emerged as a reliable and accurate diagnostic tool for the evaluation of patients with cardiac disease in several clinical settings and with proven additional diagnostic and prognostic value compared with other imaging modalities. This document has been developed by the working group on the 'application of CMR' of the Italian Society of Cardiology to provide a perspective on the current state of technical advances and clinical applications of CMR and to inform cardiologists on how to implement their clinical and diagnostic pathways with the inclusion of this technique in clinical practice. The writing committee consisted of members of the working group of the Italian Society of Cardiology and two external peer reviewers with acknowledged experience in the field of CMR.

  12. Effects of JPEG data compression on magnetic resonance imaging evaluation of small vessels ischemic lesions of the brain; Efeitos da compressao de dados JPEG na avaliacao de lesoes vasculares cerebrais isquemicas de pequenos vasos em ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Kuriki, Paulo Eduardo de Aguiar; Abdala, Nitamar; Nogueira, Roberto Gomes; Carrete Junior, Henrique; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: paulokuriki@gmail.com

    2006-01-15

    Objective: to establish the maximum achievable JPEG compression ratio without affecting quantitative and qualitative magnetic resonance imaging analysis of ischemic lesion in small vessels of the brain. Material and method: fifteen DICOM images were converted to JPEG with a compression ratio of 1:10 to 1:60 and were assessed together with the original images by three neuro radiologists. The number, morphology and signal intensity of the lesions were analyzed. Results: lesions were properly identified up to a 1:30 ratio. More lesions were identified with a 1:10 ratio then in the original images. Morphology and edges were properly evaluated up toa 1:40 ratio. Compression did not affect signal. Conclusion: small lesions were identified ( < 2 mm ) and in all compression ratios the JPEG algorithm generated image noise that misled observers to identify more lesions in JPEG images then in DICOM images, thus generating false-positive results.(author)

  13. A system dedicated to the viewing and handling of tomographic images obtained by magnetic resonance; Um sistema dedicado a visualizacao e manipulacao de imagens tomograficas obtidas por ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Slaets, Joan F.W.; Almeida, Lirio O.B. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica e Quimica; Traina, Agma J.M. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Ciencias Matematicas

    1992-12-31

    The present work describes the development of a dedicated system to be used in visualization and manipulation of a MR images. The graphics environment as well as the tool kit were developed for the dedicated TMS34010 based hardware. The developed software offers a compact kernel with primitives to support the creation and manipulation windows and menus directly in `C` language. This work is fundamental for the implementation of a user friendly interface build to operate and visualize tomographic images. This tools are essential for the selection an archiving of images planes as used in clinical applications. (author) 9 refs., 2 figs., 1 photo; e-mail: jan, agma and lirio at uspfsc.ifqsc..usp.ansp.br

  14. Numerical Calculation of Transport Based on the Drift-Kinetic Equation for Plasmas in General Toroidal Magnetic Geometry: Numerical Methods; Calculo Numerico de Transporte mediante la Ecuacion Cinetica de Deriva para Plasmas en Geometria Magnetica Toroidal: Metodos Numericos

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J. M.; Lopez-Bruna, D.

    2009-10-12

    In this report we continue with the description of a newly developed numerical method to solve the drift kinetic equation for ions and electrons in toroidal plasmas. Several numerical aspects, already outlined in a previous report [Informes Tecnicos Ciemat 1165, mayo 2009], will be treated now in more detail. Aside from discussing the method in the context of other existing codes, various aspects will be now explained from the viewpoint of numerical methods: the way to solve convection equations, the adopted boundary conditions, the real-space meshing procedures along with a new software developed to build them, and some additional questions related with the parallelization and the numerical integration. (Author) 16 refs.

  15. Annealing Effects on the Magnetization of Co-Ni-B Amorphous Nanoparticles; Propiedades Magneticas de Nanoparticulas Monodominio de la Familia (Co{sub x}Ni {sub 1-x}){sub 70}B{sub 30}

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, J M [Instituto Balseiro, Universidad Nacional de Cuyo, Centro Atomico Bariloche (Argentina)

    2001-07-01

    Chemically prepared (Co{sub x}Ni {sub 1-x}){sub 1}00{sub -y}B{sub y} (x=0.5, 0.75, 1; y{approx}30) amorphous fine particles were characterized by x-ray diffraction, DTA and TGA, and in-situ magnetic measurement as a function of annealing temperature in an inert atmosphere.Magnetic measurement performed in as prepared and {approx}150C degree annealed samples show an increase of the saturation magnetization and magnetic moment after thermal tretment.Room temperature magnetization increases by factors of {approx}3 in average.These measurements may indicate a local re-ordering of the amorphous phase at temperatures much lower than the full crystallization temperature.

  16. Equivalent Coil Model for Computing Levitation Forces Between Permanent Magnets and High Temperatures Superconductors; Modelo de Espira Equivalente para el Calculo de Fuerzas de Levitacion Magnetica entre Imanes Permanentes y Superconductores de Alta Temperatura Critica

    Energy Technology Data Exchange (ETDEWEB)

    Cavia Santos, S; Garcia-Tabares, L

    1998-05-01

    A new simple theory has been developed for the study of levitation forces between a permanent magnet and a HTc superconductor. This theory is based on the assumption that both, the magnet and the superconductor, can be modelled by an equivalent coil placed on their surface. While the current flowing through the permanent magnet is constant, the equivalent current through the superconductor can be iether corresponding to screen the overall flux or a constant current corresponding to critical current density when the superconductor is saturated. A test facility has been designed and built for measuring levitation forces at variable approaching speeds. Comparison between theoretical and experimental measurements are presented in the report as well as a general description of the test facility. (Author)

  17. Study of the influence of zirconium and gallium on the magnetic properties and microstructures of praseodymium-based permanent magnets; Estudo da influencia do zirconio e galio nas propriedades magneticas e na microestrutura dos imas permanentes a base de praseodimio

    Energy Technology Data Exchange (ETDEWEB)

    Fusco, Alexandre Giardini

    2006-07-01

    In this work was studied the influence of the addition of 0.5 at. % of zirconium and gallium on praseodymium-based HD sintered magnets obtained using a mixture of alloys. The alloys used in this study were: Pr{sub 12.6}Fe{sub 68.3}Co{sub 11.6}B{sub 6}Zr{sub 0.5}Ga{sub 1}, Pr{sub 16}Fe{sub 75.5}B{sub 8}Zr{sub 0.5}, Pr{sub 13}Fe{sub 80.5}B{sub 6}Zr{sub 0.5}. The investigation started by measuring the magnetic properties and observing the microstructure of the magnets. After that, the magnets were annealed at 1000 deg C for 2 hours followed by rapid cooling, in a total of 10 hours. This heat treatment was followed by 5 hours at the same temperature up to a total of 35 hours. Changes in the microstructure were compared to the change in the magnetic properties aiming at a proper understanding of the role of each added element in relation to the magnetically hard phase (phase {phi}). It has been shown that gallium and zirconium act as grain refiners of the matrix phase {phi}. Gallium acts in the grain and favoring of the shape stability and improvement of the magnetic properties. For the Pr{sub 14.3}Fe{sub 71.9}Co{sub 5.8}B{sub 7}Zr{sub 0.5}Ga{sub 0.5} sintered magnet the evolution of the magnetic properties after 15 hours heat treatment was: remanence from (1.25{+-}0.02) T to (1.30{+-}0.02) T, intrinsic coercivity from (1.11{+-}0.02) T to (0.87{+-}0.02) T, squareness factor from (0.68{+-}0.02) to (0.82{+-}0.02) and energy product from (285{+-}5) kJ/m{sup 3} to (317{+-}5) kJ/m{sup 3}. Zirconium has two effects on the sintered magnets. Firstly, avoiding random grain growth and enhancing anisotropy. However, by concentrating on the grain boundaries, yield reverse domains and is detrimental to the intrinsic coercivity. For the sintered Pr{sub 14.5}Fe{sub 78}B{sub 7}Zr{sub 0.5} magnet the evolution of the magnetic properties achieved after a heat treatment of 15 hours was: remanence from (1.19{+-}0.02) T to (1.25{+-}0.02) T, coercivity from (0.74{+-}0.02) T to (0.94{+-}0.02) T, squareness factor from (0.88{+-}0.02) to (0,85{+-}0.02) and energy product from (258{+-}5) kJ/m{sup 3} to (291{+-}5) kJ/m{sup 3}. For the Pr{sub 16}Fe{sub 75.5}B{sub 8}Zr{sub 0.5} sintered magnet the evolution of magnetic properties after 20 hours heat treatment was: remanence from (1.17{+-}0,02) T to (1.24{+-}0.02) T, coercivity from (0.90{+-}0,02) T to (1.22{+-}0.02) T, squareness factor from (0,93{+-}0,02) to (0.66{+-}0.02) and energy product from (258{+-}5) kJ/m{sup 3} to (291{+-}5) kJ/m{sup 3}. (author)

  18. Magnetic and microstructural properties of Ni-Zn ferrites synthesized and sintered by microwave energy; Propriedades magneticas e microestruturais de ferritas Ni-Zn sintetizadas e sinterizadas oir energia de microondas

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, D.A.; Diniz, V.C.S.; Sousa, J-P.LM.L.; Costa, A.C.F.M. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (UFScar), SP (Brazil). Dept. de Engenharia de Materiais; Cornejo, D.R. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2009-07-01

    The soft ferrites (or soft) and the Ni-Zn type are composed of spinel with cubic structure, which exhibit a permanent magnetization, called ferrimagnetism. Thus, this work will be assessed the structure and magnetic properties of ferrites Ni{sub 0},{sub 5}Zn{sub 0},{sub 5}Fe{sub 2}O{sub 4} prepared by combustion reaction using microwave energy as a source of heat and urea as fuel and after sintering by microwave energy. The synthesized powders were compacted by uniaxial pressing. The synthesized powders and the samples after sintering were characterized by XRD, SEM and magnetic measures. The diffractogram X-ray powder and the sintered samples showed the presence of the desired phase Ni{sub 0},{sub 5}Zn{sub 0},{sub 5}Fe{sub 2}O{sub 4} in both cases. The powders and sintered samples resulted in the Ms value of 8.09 emu/g and 67.73 emu/g, respectively. (author)

  19. Magnetic configuration effects on plasma transport under Neutral Beam Injection at TJ-II (Simulation); Efectos de Configuracion Magnetica en el Transporte de Plasma durante la Inyeccion de Haces Neutros en el TJ-II (Simulacion)

    Energy Technology Data Exchange (ETDEWEB)

    Guasp, J.; Fuentes, C.; Liniers, M.

    2001-07-01

    A systematic analysis of magnetic configurations (27 in total), using a Transport model including impurity dynamics and sputtering effects has been done. For small size configurations or those close to rational t values there is radioactive collapse, independently of the external gas puffing (GP) strategy chosen. The reason is the insufficiency of observed power, either by the high shine through losses due to their low radii, or by the increase of fast ion orbit losses near the resonances. For the majority of configurations without collapse, fast ion orbit losses for CO injection (going in the same direction than the toroidal magnetic field) are higher, and in consequence the power absorption and the plasma {beta} achieved are laser, than for the opposite direction. Nevertheless in the region placed just above the main resonances (1/3 and 1/2 per period) this situation reverses. The reasons have been analysed and explained at previous studies. A consequence of this fact is that the optima of confinement for the Counter case are shifted towards higher t values than the CO one, with higher plasma {beta}, except near the resonances. As usual the balanced case is in between. The optima achieving stationary state are very close (and often are coincident) with those lacking that restriction. The best configuration (highest average {beta}) for balanced injection, with <{beta}>=1.1% and central value 3.2%, although in this region the results are rather insensitive to configuration and GP strategy. The configurations placed around the 100{sub 4}4 would need also the lowest power entering the torus in order to avoid collapse and to achieve an acceptable NBI absorption level. (Author) 12 refs.

  20. Magnetic spires for the detection of the position of the plasma column in a Tokamak (linear approximation); Espiras magneticas para la deteccion de la posicion de la columna de plasma en un Tokamak (aproximacion lineal)

    Energy Technology Data Exchange (ETDEWEB)

    Colunga S, S

    1990-07-15

    In this report the simplified analysis of a method to detect the movement of the plasma column of a tokamak in the vertical direction and of the biggest radius is given. The peculiar case of the Tokamak Novillo of the Plasma Physics Laboratory of the ININ is studied. (Author)

  1. Dysgenesis of the corpus callosum and associated malformaaation{sup :} computed tomography and magnetic resonance imaging findings; Disgenesia do corpo caloso e mas-formacoes associadas: achados de tomografia computadorizada e ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Montandon, Cristiano; Montandon Junior, Marcelo Eustaquio [Colegio Brasileiro de Radiologia e Diagnostico por Imagem (CBR), Sao Paulo, SP (Brazil); Ribeiro, Flavia Aparecida de Sousa; Lobo, Leonardo Valadares Barbosa; Teixeira, Kim-Ir-Sen Santos [Goias Univ., Goiania (Brazil). Hospital de Clinicas. Dept. de Diagnostico por Imagem e Anatomia Patologica]. E-mail: cabeca2@terra.com.br

    2003-10-01

    Callosal dysgenesis is a malformation of the corpus callosum with origins in the embryogenesis of the telencephalon. We reviewed the computed tomography and magnetic resonance imaging findings of 11 patients with callosal dysgenesis and one patient with normal corpus callosum associated with a lipoma. The patients were divided into three distinct groups: total agenesis (three patients), partial agenesis (six patients) and hypoplasia (two patients). Associated abnormalities were observed in nine patients, including Chiari II malformation (one patient), schizencephaly (one patient), interhemispheric cyst (two patients), Dandy-Walker cyst (one patient), nodular heterotopy (one patient) and lipoma of the corpus callosum (four patients). This paper presents a review that may contribute to the diagnosis of these disorders. (author)

  2. Preparation of EVA/silica nano composites characterized with solid state nuclear magnetic resonance; Obtencao de nanocomposito de EVA/SILICA e caracterizacao por ressonancia magnetica nuclear no estado solido

    Energy Technology Data Exchange (ETDEWEB)

    Passos, Adriano A; Tavares, Maria I.B.; Neto, Roberto C.P.; Moreira, Leonardo A; Ferreira, Antonio G., E-mail: mibt@ima.ufrj.br [Centro de Tecnologia, Instituto de Macromoleculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Nano composites of poly(ethylene-co-vinyl acetate)/silica (SiO{sub 2}) with dimensions of ca. 40 nm were prepared via solution intercalation employing chloroform as a solvent. They were mainly characterized with nuclear magnetic resonance spectroscopy (NMR) employing carbon-13 (polymeric matrix), silicon-29 (nanoparticles) and through the determination of the proton spin-lattice relaxation time in the rotating frame (T{sub 1{rho}H}) (polymer matrix). From the NMR results it was inferred that up to 5% of silica in mass a well dispersed nano composite was obtained, owing to a strong interaction between silica and the EVA matrix. (author)

  3. Clinical recommendations of cardiac magnetic resonance, Part II: inflammatory and congenital heart disease, cardiomyopathies and cardiac tumors: a position paper of the working group 'Applicazioni della Risonanza Magnetica' of the Italian Society of Cardiology.

    Science.gov (United States)

    Pontone, Gianluca; Di Bella, Gianluca; Silvia, Castelletti; Maestrini, Viviana; Festa, Pierluigi; Ait-Ali, Lamia; Masci, Pier Giorgio; Monti, Lorenzo; di Giovine, Gabriella; De Lazzari, Manuel; Cipriani, Alberto; Guaricci, Andrea I; Dellegrottaglie, Santo; Pepe, Alessia; Marra, Martina Perazzolo; Aquaro, Giovanni D

    2017-04-01

    The current document was developed by the working group on the 'application of cardiac magnetic resonance' of the Italian Society of Cardiology to provide a perspective on the current state of technical advances and clinical cardiac magnetic resonance applications and to inform cardiologists how to implement their clinical and diagnostic pathway with the introduction of this technique in the clinical practice. Appropriateness criteria were defined using a score system: score 1-3 = inappropriate (test is not generally acceptable and is not a reasonable approach for the indication), score 4-6 = uncertain (test may be generally acceptable and may be a reasonable approach for the indication but more research and/or patient information is needed to classify the indication definitively) and score 7-9 = appropriate (test is generally acceptable and is a reasonable approach for the indication).

  4. Nuclear magnetic resonance system with continuous flow of polarized water to obtain the traceability to static magnetic fields; Sistema de ressonancia magnetica nuclear com fluxo continuo de agua polarizada para obtencao da rastreabilidade para campos magneticos estaticos

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ramon Valls; Nazarre, Diego Joriro, E-mail: ramon@ipt.br [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    2013-07-01

    We have developed a system to obtain the traceability of field or magnetic induction intensity in the range of 2 μT up to 2 T, even in the presence of magnetic field gradients or noisy environments. The system is based on a nuclear magnetic resonance magnetometer, built in streaming water. The calibration procedure of a coil for magnetic field generation is described, as well as the results obtained and the estimated uncertainty (author)

  5. Characterization of polymer-type ionic conductors using nuclear magnetic resonance and thermal analysis. Humidity sensor; Caracterizacao de condutores ionicos de tipo polimerico por ressonancia magnetica nuclear (RMN) e analises termicas. Sensor de umidade

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcante, Maria Goretti

    1992-04-01

    We report a study using Nuclear Magnetic Resonance (NMR), Thermogravimetry Analysis, Differential Scanning Calorimetry and Infrared Spectroscopy in polymeric complexes formed poly(ethylene oxide), (PEO), and lithium salts. These complexes have have shown a large potential for technological applications in batteries, sensors, etc. We developed and characterized humidity sensors and discussed how the humidity affects the conformation of the complexes, the mobility of ionic species, and the polymeric chains. The results indicate that the hydration affects the conformation of polymeric complexes by plasticizing the water, which induces a volumetric expansion in the PEO chain. The processes was completely reversible for the level of hydration studied. NMR was used to distinguish the movement of polymeric chains from the movement of the ionic species. From the analysis of the second moment of resonance lines from the study of the nuclear relaxation we were able to estimate the average distance between the ionic species and the proton in the complexes chains. The behaviour of spin -lattice relaxation of hydrogen and fluorine in the P(EO) - Li B F, as a function of temperature and frequency reflects the nature of the disorder and the complexity of the ionic conduction process in these materials. (author). 91 refs., 69 figs., 2 tabs.

  6. A system dedicated to the viewing and handling of tomographic images obtained by magnetic resonance; Um sistema dedicado a visualizacao e manipulacao de imagens tomograficas obtidas por ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Slaets, Joan F.W.; Almeida, Lirio O.B. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica e Quimica; Traina, Agma J.M. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Ciencias Matematicas

    1993-12-31

    The present work describes the development of a dedicated system to be used in visualization and manipulation of a MR images. The graphics environment as well as the tool kit were developed for the dedicated TMS34010 based hardware. The developed software offers a compact kernel with primitives to support the creation and manipulation windows and menus directly in `C` language. This work is fundamental for the implementation of a user friendly interface build to operate and visualize tomographic images. This tools are essential for the selection an archiving of images planes as used in clinical applications. (author) 9 refs., 2 figs., 1 photo; e-mail: jan, agma and lirio at uspfsc.ifqsc..usp.ansp.br

  7. Study of proton and carbon 13 nuclear magnetic resonance spectra of an allyl phenol derivatives series; Estudo de espectros de ressonancia magnetica nuclear protonica e de carbono 13 de uma serie de derivados de alilfenois

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Thais Horta Alvares da [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Dept. de Produtos Farmaceuticos; Oliveira, Alaide Braga de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica

    1991-12-31

    Quaternary ammonium salt derivates of natural ally phenols were synthesized with the purpose of obtaining peripheral analgesics. Eugenol, O-methyleugenol and safrole were submitted to nitration, reduction, per methylation. The amines were also transformed into their hydro chlorides. The {sup 1} HNMR spectra of the nitro compounds, amines, amine hydro chlorides, quaternary ammonium salts and dymethylamines were analysed, as well as the {sup 13} C NMR spectra of the nitro compounds and of the quaternary ammonium salts. (author). 8 refs., 4 tabs.

  8. Analysis of oil content in sunflower seeds with nuclear magnetic ressonance and `SOXHLET` methods; Determinacao do teor de oleo em sementes de girassol pelos metodos de ressonancia magnetica nuclear e soxhlet

    Energy Technology Data Exchange (ETDEWEB)

    Ungaro, Maria Regina Goncalves [Instituto Agronomico de Campinas, SP (Brazil). Secao de Oleaginosas; Toledo, Nilva Maria Prestes de [Instituto Agronomico de Campinas, SP (Brazil). Secao Tecnica Experimental e Calculo; Teixeira, Joao Paulo Feijao [Instituto Agronomico de Campinas, SP (Brazil). Secao de Fitoquimica; Suassuna Filho, Jose [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Dept.de Fisica

    1993-12-31

    Individual and group of seeds of some sunflower populations were utilized in order to evaluate the feasibility of oil content evaluations by the Nuclear Magnetic Resonance method (NMR). Correlation analysis with the extractive method (Soxhlet) was performed. The results showed that: the oil in the seeds behaved like a liquid in the NMR analysis; there was a high and positive correlation (r = 0,93) between NMR and Soxhlet; there was no correlation between seed weight and oil content; the observed variability in oil content among seeds of a plant were higher than between plants of a population; these values indicate the importance of making individual analysis of oil content by the NMR method for the sunflower breeding for oil content. (author) 7 refs., 2 figs., 4 tabs.

  9. ({sup 1} H, {sup 13} C and {sup 31} P) NMR of phosphonic acid derivatives; Ressonancia magnetica nuclear ({sup 1} H, {sup 13} C, {sup 31} P) de derivados do acido fosfonico

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Valdevino; Costa, Valentim E. Uberti [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Quimica

    1992-12-31

    In the last years the development of phosphates analogues in the medical and agricultural pesticides has being very expressive. {sup 1} H, {sup 13} C and mainly {sup 31} P NMR are used for stereochemical and conformational analysis, and reactivity studies on the compounds resulting from those chemical processes 2 refs., 4 figs., 1 tab.

  10. Numerical Calculation of Transport Based on the Drift Kinetic Equation for plasmas in General Toroidal Magnetic Geometry; Calculo Numerico del Transporte mediante la Ecuacion Cinetica de Deriva para Plasmas en Geometria Magnetica Toroidal: Preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J. M.; Lopez-Bruna, D.

    2009-12-11

    This report is the first of a series dedicated to the numerical calculation of the evolution of fusion plasmas in general toroidal geometry, including TJ-II plasmas. A kinetic treatment has been chosen: the evolution equation of the distribution function of one or several plasma species is solved in guiding center coordinates. The distribution function is written as a Maxwellian one modulated by polynomial series in the kinetic coordinates with no other approximations than those of the guiding center itself and the computation capabilities. The code allows also for the inclusion of the three-dimensional electrostatic potential in a self-consistent manner, but the initial objective has been set to solving only the neoclassical transport. A high order conservative method (Spectral Difference Method) has been chosen in order to discretized the equation for its numerical solution. In this first report, in addition to justifying the work, the evolution equation and its approximations are described, as well as the baseline of the numerical procedures. (Author) 28 refs.

  11. Numerical Calculation of Transport Based on the Drift-Kinetic Equation for Plasmas in General Toroidal Magnetic Geometry: Convergence and Testing; Calculo Numerico del Transporte mediante la Ecuacion Cinetica de Deriva para Plasmas en Geometria Magnetica Toroidal: Convergencia y Comprobaciones

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J. M.; Lopez-Bruna, D.

    2009-12-11

    This report is the third of a series [Informes Tecnicos Ciemat 1165 y 1172] devoted to the development of a new numerical code to solve the guiding center equation for electrons and ions in toroidal plasmas. Two calculation meshes corresponding to axisymmetric tokamaks are now prepared and the kinetic equation is expanded so the standard terms of neoclassical theory --fi rst order terms in the Larmor radius expansion-- can be identified, restricting the calculations correspondingly. Using model density and temperature profiles for the plasma, several convergence test are performed depending on the calculation meshes and the expansions of the distribution function; then the results are compared with the theory [Hinton and Hazeltine, Rev. Mod. Phys. (1976)]. (Author) 18 refs.

  12. Peritendinous calcinosis of calcaneus tendon associated with dermatomyositis: correlation between conventional radiograph, ultrasound, magnetic resonance imaging and gross surgical pathology; Calcinose peritendinea do tendao calcaneo associada a dermatomiosite: correlacao entre radiografia convencional, ultra-sonografia, ressonancia magnetica e macroscopia cirurgica

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Ana Claudia Ferreira; Gomide, Lidyane Marques de Paula; Lemes, Marcella Stival [Universidade Federal de Goias (UFG), Goiana, GO (Brazil). Faculdade de Medicina. Hospital das Clinicas; Costa, Edegmar Nunes; Rocha, Valney Luiz da [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Faculdade de Medicina. Dept. de Ortopedia; Machado, Marcio Martins; Santos Junior, Rubens Carneiro dos; Barros, Nestor de; Cerri, Giovanni Guido [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Faculdade de Medicina. Dept. de Radiologia; Sernik, Renato Antonio [Sao Paulo Univ., SP (Brazil). Hospital das Clinicas. Inst. de Radiologia; Nunes, Rodrigo Alvarenga [Universidade do Vale do Sapucai (UNIVAS), Pouso Alegre, MG (Brazil). Faculdade de Ciencias Medicas; Albieri, Alexandre Daher [Hospital de Acidentados de Goiania, GO (Brazil)

    2006-01-15

    Interstitial calcinosis is an uncommon condition in which there is either localized or widely disseminated deposition of calcium in the skin, subcutaneous tissues, muscles, and tendons. Calcinosis is often associated with collagen diseases, scleroderma and dermatomyositis. The authors report a case of interstitial calcinosis associated with dermatomyositis studied with conventional radiograph, ultrasound and magnetic resonance imaging, and correlate the imaging findings with the results of surgical pathology gross examination. (author)

  13. Synthesis, characterization and study of the magnetic properties of a coordination polymer containing cobalt(II) and copper(II); Sintese, caracterizacao e estudo das propriedades magneticas de um polimero de coordenacao contendo cobalto(II) e cobre(II)

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Tamyris T. da; Stumpf, Humberto O.; Pereira, Cynthia L.M., E-mail: cynthialopes@ufmg.br [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Pires, Heber S.; Oliveira, Luiz F.C. de [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Juiz de Fora, MG (Brazil); Pedroso, Emerson F. [Departamento de Quimica, Centro Federal de Educacao Tecnologica de Minas Gerais, Belo Horizonte, MG (Brazil); Nunes, Wallace C. [Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ (Brazil)

    2012-07-01

    This work describes the synthesis and characterization of two new compounds with ligand opy (N-(2-pyridyl)oxamate): the copper(II) precursor [Me{sub 4}N]{sub 2}[Cu(opy){sub 2}].5H{sub 2}O and Co{sup II} Cu{sup II} coordination polymer {l_brace}[Co Cu(opy){sub 2}]{r_brace}{sub n}x4nH{sub 2}O. This latter compound was obtained by reaction of [Me{sub 4}N]{sub 2}[Cu(opy){sub 2}].5H{sub 2}O and CoCl{sub 2}.6H{sub 2}O in water. The heterobimetallic Co{sup II} Cu{sup II} chain was characterized by elemental analysis, IR spectroscopy, thermogravimetry and magnetic measurements. Magnetic characterization revealed typical behavior of one-dimensional (1D) ferrimagnetic chain as shown in the curves of temperature (T) dependence of magnetic susceptibility ({chi}{sub M}), in the form of {chi}{sub M}T versus T, and dependence of magnetization (M) with applied field (H). (author)

  14. Prenatal diagnosis of conjoined twins by magnetic resonance imaging: report of two cases; Diagnostico pre-natal de gemeos unidos com uso da ressonancia nuclear magnetica: relato de dois casos

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Alex Sandro Rolland de; Medeiros, Cynthia Coelho de; Lins, Glaucia Virginia de Queiroz [Instituto Materno Infantil Professor Fernando Figueira (IMIP), Recife, PE (Brazil); Noronha Neto, Carlos [Centro Integrado de Saude Amaury de Medeiros (CISAM), Recife, PE (Brazil); Lima, Marcelo Marques de Souza [Universidade Federal de Sao Paulo (UNIFESP/EPM), Sao Paulo, SP (Brazil)]. E-mail: alexrolland@uol.com.br

    2006-07-15

    Conjoined twins have a rare prevalence and special curiosity among physicians and the general population. The reported frequency varies from 1:50,000 to 1:200,000 pregnancies. Its early diagnosis becomes very important when we think about pregnancy management, method of delivery and neonatal care. We describe two cases of conjoined twins diagnosed by ultrasound and magnetic resonance during prenatal care with the aim to better studying the fetus anatomy. The first conjoined twins were cephalopagus sharing head, thorax and abdominal wall and with two pelvis and four arms and four legs. The second were thoracopagus, united by thorax and part of abdomen. Magnetic resonance imaging contribution was not important to diagnose conjoined twins. However, it was useful to describe the shared organs, contributing to define fetal outcome. (author)

  15. Comparative study between body and surface coils in magnetic resonance mammography of silicone prosthesis; Estudo comparativo entre bobinas de corpo e superficie na mamografia por ressonancia magnetica de proteses de silicone

    Energy Technology Data Exchange (ETDEWEB)

    Scaranelo, Anabel Medeiros [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: anabelms@uol.com.br

    2001-04-01

    Magnetic resonance imaging scans using predefined parameters were performed in patients with silicone breast implants. The same group of patients was submitted to magnetic resonance imaging scans using surface breast coils and body coils, and the results were compared. A total of 43 single-lumen silicone-gel breast implants in 24 patients were examined. The signal-to-noise ratio was greater for the breast coil than for the body coil. Radial folds were identified with equal resolution by both in almost 82% of the cases on the right side and 95% on the left side. In about 5% of the cases the folds were seen exclusively when the breast coil used. The linguine sign was almost equally with both methods. In just one case the linguine sign was observed only by using the breast coil. Identification of building or irregularity of contours were concordant using both techniques. We concluded that although magnetic resonance imaging quality is better using a dedicated coil, silicone breast implants can be assessed with the same diagnostic accuracy using a body coil. (author)

  16. Magnetic resonance imaging in the evaluation of standard radiotherapy field borders in patients with uterine cervix cancer;Ressonancia magnetica para avaliacao dos limites dos campos classicos de radioterapia em pacientes portadoras de neoplasia maligna de colo uterino

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Geison Moreira; Dias, Rodrigo Souza; Giordani, Adelmo Jose; Segreto, Helena Regina Comodo; Segreto, Roberto Araujo, E-mail: segreto.dmed@epm.b [Universidade Federal de Sao Paulo (UNIFESP-EPM), SP (Brazil). Unit of Radioterapy; Ribalta, Julisa Chamorro Lascasas [Universidade Federal de Sao Paulo (UNIFESP-EPM), SP (Brazil). Dept. de Gynecology

    2010-05-15

    Objective: to evaluate, by means of magnetic resonance imaging, the standardized field borders in radiotherapy for malignant neoplasm of uterine cervix, and to determine the role of this method in the reduction of possible planning errors related to the conventional technique. Materials and methods: magnetic resonance imaging studies for planning of treatment of 51 patients with uterine cervix cancer were retrospectively analyzed. The parameters assessed were the anterior and posterior field borders on sagittal section. Results: The anterior field border was inappropriate in 20 (39.2%) patients and geographic miss was observed in 37.3% of cases in the posterior border. The inappropriateness of both field borders did not correlate with clinical parameters such as patients' age, tumor staging, histological type and degree. Conclusion: the evaluation of standardized field borders with the use of magnetic resonance imaging has demonstrated high indices of inappropriateness of the lateral field borders, as well as the relevant role of magnetic resonance imaging in the radiotherapy planning for patients with uterine cervix cancer with a view to reduce the occurrence of geographic miss of the target volume. (author)

  17. Magnetic nanoparticles of NiCuZn tested in different conditions in catalysis for biodiesel; Nanoparticulas magneticas de NiCuZn testadas em diferentes condicoes na catalise para biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, J.; Silva, F.N.; Silva, A.S.; Pereira, K.R.O.; Costa, A.C.F.M., E-mail: joeldadantas@yahoo.com.br [Universidade Federal de Campina Grande (LabSMaC/UFCG), PB (Brazil). Laboratorio de Sintese de Materiais Ceramicos

    2014-07-01

    In this work it was used magnetic nanoparticles Ni{sub 0,2}Cu{sub 0,3}Zn{sub 0,5}Fe{sub 2}O{sub 4}, chemical and thermally stable, under different conditions in catalysis for biodiesel. The magnetic characteristic of such material allows the catalyst recovery after the reactions by applying a permanent magnet. It was proposed to evaluate the performance of the nanomagnetic catalyst Ni{sub 0,2}Cu{sub 0,3}Zn{sub 0,5}Fe{sub 2}O{sub 4} in the transesterification, modifying the processing variables (temperature, time, molar ratio of oil:alcohol and catalyst amount). The nanoparticles were synthesized by combustion reaction and characterized by XRD, TG, BET, magnetic measurements and gas chromatography. The results revealed the formation of inverse spinel phase, type B(AB){sub 2}O{sub 4}, presenting isotherm profile classified as type V, with hysteresis loop of type 3 (H3). The magnetic hysteresis curve showed a characteristic behavior of soft magnetic material. GC analysis confirmed that nanoparticles were catalytically active, since they were superior to the reaction conducted without the catalyst presence. Besides, the reactions suffered considerable influence due to the changes of the independent variables. (author)

  18. Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography; Vias colaterais porto-sistemicas exuberantes em portadores de hipertensao portal: demonstracao pela angiografia por ressonancia magnetica com gadolinio

    Energy Technology Data Exchange (ETDEWEB)

    Caldana, Rogerio Pedreschi; Bezerra, Alexandre Araujo Sergio; Cecin, Alexnadre Oliveira; Souza, Luis Ronan Marques Ferreira de; Goldman, Susan Menasce; D' Ippolito, Giuseppe; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), Sao Paulo, SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: rogercal@uol.com.br

    2003-03-01

    To demonstrate the usefulness of gadolinium-enhanced magnetic resonance angiography in the evaluation of prominent porto-systemic collateral pathways. We reviewed the images from 40 patients with portal hypertension studied with gadolinium-enhanced magnetic resonance angiography and selected illustrative cases of prominent porto-systemic collateral pathways. The scans were performed using high field equipment (1.5 Tesla) and a 3 D volume technique. Image were obtained after intravenous injection of paramagnetic contrast media using a power injector. Magnetic resonance angiography demonstrated with precision the porto-systemic collateral pathways, particularly when investigating extensive territories or large vessels. The cases presented show the potential of this method in the investigation of patients with portal hypertension. Gadolinium-enhanced magnetic resonance angiography is a useful method for the evaluation of patients with portal hypertension and prominent collateral pathways. (author)

  19. Proceedings of the 11. Brazilian meeting on magnetic resonance. Short courses on NMR. Abstracts and program; Anais da 11. Jornada brasileira de ressonancia magnetica. Mini-cursos em RMN. Resumos e programa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This annual meeting, held in Brazil from August 4 - 6, 2010 comprised : mini-courses about the use of nuclear magnetic resonance for various analytical purposes; major conferences and short conferences with invited speakers from Brazil and other countries; results from research works, most being carried out by scientific groups from various Brazilian R and D institutions, presented as oral communications and as congress panels/posters. Prizes to remarkable works of undergrad and post-grad students have been awarded, and a General Assembly meeting of AUREMN, the Brazilian Association of Nuclear Magnetic Resonance Users, also took place at the end of the event. Main topics of the research works presented at this meeting were thus distributed: 52% in chemical sciences (mainly organic chemistry, both experimental and theoretical works), 28% in applied life sciences (agricultural and food sciences, biological sciences and medicine), 18% in materials science (including nanocomposites, petroleum and alternative fuels), and 4% regarding development of equipment accessories for improving NMR techniques and environmental science-related themes

  20. Value of magnetic resonance imaging in the radiotherapy planning of tumours of the uterine cervix: preliminary results; Valor da ressonancia magnetica no planejamento radioterapico dos tumores de colo de utero: resultados preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Justino, Pitagoras Baskara; Carvalho, Heloisa de Andrade [Sao Paulo Univ., SP (Brazil). Hospital das Clinicas. Inst. de Radiologia]. E-mail: pitagorasb@hotmail.com; Baroni, Ronaldo Hueb; Blasbalg, Roberto; Leite, Claudia da Costa [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Dept. de Radiologia

    2005-12-01

    Objective: To assess the rate of geographic miss on conventional radiotherapy planning of patients with cervical cancer, using magnetic resonance imaging. Materials and methods: Thirty-two patients with squamous cell carcinoma of the uterine cervix were studied. Magnetic resonance imaging of the pelvis was performed after clinical staging. Magnetic resonance imaging findings were compared with the classic fields described for the 'box' technique. Target volume within less than 1 cm margins of the fields' limits was considered as geographic miss. Results: Classical radiation field limits were inadequate in 24 cases (75%), all in the anterior (46%) or posterior (40%) border of the lateral fields. Conclusion: Magnetic resonance detected a high probability of geographic miss on conventional radiotherapy planning in this population, both in initial and advanced stages of the disease. (author)

  1. Calculation of the electronic and magnetic structures of 3d impurities in the Hcp Fe matrix; Calculo da estrutura eletronica e magnetica de impurezas 3d na matriz do Fe HCP

    Energy Technology Data Exchange (ETDEWEB)

    Franca, Fernando

    1995-12-31

    In this work we investigate the local magnetic properties and the electronic structure of HCP Fe, as well introducing transition metals atoms 3d (Cs, Ti, Cr, Mn, Co, Ni, Cu, Zn) in HCP iron matrix. We employed the discrete variational method (DVM), which is an orbital molecular method which incorporate the Hartree-Fock-Slater theory and the linear combination of atomic orbitals (LCAO), in the self-consistent charge approximation and the local density approximation of Von Barth and Hedin to the exchange-correlation potential. We used the embedded cluster model to investigate the electronic structure and the local magnetic properties for the central atom of a cluster of 27 atoms immersed in the microcrystal representing the HCP Fe. (author) 32 refs., 19 figs., 2 tabs.

  2. Preparation of combustible material from high sulphur coal by means of pyrolysis: magnetic separation; Obtencion de combustibles limpios a partir de carbones con altos contenidos en azure mediante procesos de pirolisis: separacion magnetica

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-11-01

    Basic studies on coal desulphurization by pyrolysis have been carried out with a series of low rank coals with high total sulphur contents and differences in the distribution of sulphur forms. The evolved sulphur compounds were studied by sulphide selective electrode H{sub 2}S and Fourier transform infrared (FTIR) spectroscopy. The mechanisms affecting the sulphur removal during pyrolysis have been studied by scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD) and photoelectronic spectroscopy (XPS). A sample coal of 11 Tm, representative of the Teruel basins was processed at pilot scale in a rotary kiln (coal HR). A series of pyrolysis runs simulating the experimental conditions of the rotary kiln were also carried out in laboratory scale. The magnetic behaviour of the chars from the rotary kiln and from the lab-scale pyrolysis was tested. The efficiency of the desulphurization, including pyrolysis and magnetic separation, was calculated. Chars from rotary kiln were tested by thermogravimetric analysis, air reactivity and carbon efficiency combustion in fluidized bed.

  3. Creutzfeldt-Jakob disease, Heidenhain variant: case report with MRI (DWI) findings; Doenca de Creutzfeldt-Jakob forma Heidenhain: relato de caso com achados de ressonancia magnetica e DWI

    Energy Technology Data Exchange (ETDEWEB)

    Arruda, Walter Oleschko; Bordignon, Kelly C; Milano, Jeronimo B; Ramina, Ricardo [Instituto de Neurologia de Curitiba, PR (Brazil)

    2004-06-01

    Creutzfeldt-Jakob disease (CJD) is a pre senile dementia characterized by rapidly progressive mental deterioration, myoclonic jerking, and other less common neurological signs. Few accentuates cases have been described in Brazil. A 54-year-old white woman, was admitted in our service with a month history of progressive, bilateral cortical blindness. After admission, she developed right partial motor seizures (right facial, upper and lower limbs), she became progressively aphasic (mixed aphasia). Seizures were controlled with phenytoine, but she developed choreoathetotic movements on her right dimidium, with partial control after introduction of chlorpromazine 25 mg q/d. She could no longer stand up or walk due to severe ataxia. The first EEG (October, 2001) showed left hemisphere severe seizure activity (status epilepticus partial is). She was delivered home with enteral nutrition, phenytoine, chlorpromazine and mepacrine 100 mg q d. The following laboratory tests were negative or normal: blood series, platelets, ESR, kidney and liver function, copper, ceruloplasmin, Vedril, HIV, HTLV-1, lactate, and cerebral Dsa (performed in other service). A spinal tap with normal opening pressure was perform and CSFR examination was normal. CSFR 14-3-3 protein was positive, CSF specific neuronal enolase 7.5 ng/ml(normal). Genetic study of PRNP gene did not disclosed any known mutation. A MRI (October, 2001) showed areas of hyperintense signal (T 2 and FLAIR) without Gd-enhancement on T1, in the left temporal lobe and in both occipital lobes; basal ganglia have a normal appearance. DWI imaging showed bright areas at the same sites. An EEG (March, 2002) disclosed a periodical sharp triphasic waves pattern, suggestive of CJD. A second MRI (April, 2002) showed mild generalized atrophy, no ventricular dilatation, and the hyperintense sites disappeared. She remained clinically stable and under use of chlorpromazine and mepacrine until she died due to pulmonary complications on April, 2003. (author)

  4. General catalogue of products and services - geology. AERO data base; 2. ed; Catalogo geral de produtos e servicos - geologia. Base de dados AERO

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The catalogue in the second edition aims at presenting to the user a general idea on the aerogeophysical projects of Brazil database (AERO) which belongs to SIGA (Brazilian geological information system). The 151 documents (projects) are listed as follows: 52 projects performed by CPRM/DNPM - Departamento Nacional de Producao Mineral; 33 projects performed by CNEN - Commissao Nacional de Energia Nuclear and NUCLEBRAS; 7 projects executed by State government and private companies; and 59 projects executed for PETROBRAS 159 figs., 5 tabs.

  5. Two children with chronic progressive radiation myelopathy

    International Nuclear Information System (INIS)

    Ohta, Hideaki; Takai, Kenji; Hosoi, Gaku; Okamura, Takayuki; Osugi, Yuko; Ishihara, Shigehiko; Hara, Junichi; Tawa, Akio; Okada, Shintaro

    1995-01-01

    We report two patients who developed chronic progressive radiation myelopathy (CPRM). Patient 1 was a 16-year-old boy with group IV rhabdomyosarcoma of cervical soft tissue. He underwent partial excision of the tumor and received systemic and intrathecal chemotherapy and 44 Gy of local radiotherapy (C4 through Th3). These therapies were followed by high-dose chemotherapy including thio-TEPA and busulfan with autologous bone marrow rescue. One year after the completion of the therapies, he developed CPRM. Patient 2 was a 15-year-old girl with acute lymphoblastic leukemia on the 3rd complete remission. She received 18 Gy of irradiation to whole brain during the 1st remission and another 18 Gy to whole brain and 9 Gy to spinal cord after her 1st CNS relapse. After successful reinduction therapy for the 2nd relapse in CNS and bone marrow, she underwent an allogeneic bone marrow transplantation (BMT). The preconditioning regimen consisted of 12 Gy total body irradiation, thio-TEPA and cyclophosphamide. Seven months after BMT, she developed CPRM at C0-C1 level, which was included in the area of whole-brain irradiation. In both patients, MR images showed a swelling of the cervical cord and ring-like images by gadolinium enhancement. Their neurological disability transiently responded to the administration of corticosteroid, but they developed progressive quadriplegia. Although it is reported that a dose of 45-50 Gy may be safe, these cases suggest that administration of high-dose chemotherapy combined with intrathecal chemotherapy and radiotherapy to the cord might increase the rink of developing CPRM. (author)

  6. Two children with chronic progressive radiation myelopathy

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, Hideaki; Takai, Kenji; Hosoi, Gaku; Okamura, Takayuki; Osugi, Yuko; Ishihara, Shigehiko; Hara, Junichi; Tawa, Akio; Okada, Shintaro [Osaka Univ. (Japan). Faculty of Medicine

    1995-06-01

    We report two patients who developed chronic progressive radiation myelopathy (CPRM). Patient 1 was a 16-year-old boy with group IV rhabdomyosarcoma of cervical soft tissue. He underwent partial excision of the tumor and received systemic and intrathecal chemotherapy and 44 Gy of local radiotherapy (C4 through Th3). These therapies were followed by high-dose chemotherapy including thio-TEPA and busulfan with autologous bone marrow rescue. One year after the completion of the therapies, he developed CPRM. Patient 2 was a 15-year-old girl with acute lymphoblastic leukemia on the 3rd complete remission. She received 18 Gy of irradiation to whole brain during the 1st remission and another 18 Gy to whole brain and 9 Gy to spinal cord after her 1st CNS relapse. After successful reinduction therapy for the 2nd relapse in CNS and bone marrow, she underwent an allogeneic bone marrow transplantation (BMT). The preconditioning regimen consisted of 12 Gy total body irradiation, thio-TEPA and cyclophosphamide. Seven months after BMT, she developed CPRM at C0-C1 level, which was included in the area of whole-brain irradiation. In both patients, MR images showed a swelling of the cervical cord and ring-like images by gadolinium enhancement. Their neurological disability transiently responded to the administration of corticosteroid, but they developed progressive quadriplegia. Although it is reported that a dose of 45-50 Gy may be safe, these cases suggest that administration of high-dose chemotherapy combined with intrathecal chemotherapy and radiotherapy to the cord might increase the rink of developing CPRM. (author).

  7. General catalogue of products and services - geology. AERO data base; 2. ed; Catalogo geral de produtos e servicos - geologia. Base de dados AERO

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The catalogue in the second edition aims at presenting to the user a general idea on the aerogeophysical projects of Brazil database (AERO) which belongs to SIGA (Brazilian geological information system). The 151 documents (projects) are listed as follows: 52 projects performed by CPRM/DNPM - Departamento Nacional de Producao Mineral; 33 projects performed by CNEN - Commissao Nacional de Energia Nuclear and NUCLEBRAS; 7 projects executed by State government and private companies; and 59 projects executed for PETROBRAS 159 figs., 5 tabs.

  8. General catalogue of products and services - geology. AERO data base. 2. ed.

    International Nuclear Information System (INIS)

    1995-01-01

    The catalogue in the second edition aims at presenting to the user a general idea on the aerogeophysical projects of Brazil database (AERO) which belongs to SIGA (Brazilian geological information system). The 151 documents (projects) are listed as follows: 52 projects performed by CPRM/DNPM - Departamento Nacional de Producao Mineral; 33 projects performed by CNEN - Commissao Nacional de Energia Nuclear and NUCLEBRAS; 7 projects executed by State government and private companies; and 59 projects executed for PETROBRAS

  9. Getting an MRI (For Kids)

    Medline Plus

    Full Text Available ... resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures ... educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995- ...

  10. Chronological observation in early radiation myelopathy of the cervical spinal cord; Gadolinium-enhanced MRI findings in two cases

    Energy Technology Data Exchange (ETDEWEB)

    Hirota, Saeko; Yoshida, Shoji; Soejima, Toshinori (Hyogo Medical Center for Adults, Akashi (Japan)) (and others)

    Gd-enhanced MR images of two patients with clinically and histopathologically diagnosed chronic progressive radiation myelitis (CPRM) were observed chronologically. One of them had had nasopharyngeal cancer and received radiotherapy at a dose of 100 Gy to the C1-2 level of the spinal cord. She developed CPRM 25 months after the termination of radiotherapy. The other had had malignant lymphoma originating from the tonsil and received chemoradiotherapy. The dose delivered to her cervical spinal cord was 40 Gy, and she developed CPRM 30 months later. Gd-enhanced MRI in the early phase revealed a small crescent-shaped nidus with or without a very small central nonenhanced area in both cases. Enhancement was not great. At that time, patients noticed only the inability to perceive pain and temperature or paresthesia in the opposite side. In a few months, MRI revealed a much more strongly enhanced and larger nidus with enlargement of a central nonenhanced area accompanied by long segmental cord enlargement. The patients' neurological symptoms had also progressed, with hemiparesis developing, for example. (author).

  11. Chronological observation in early radiation myelopathy of the cervical spinal cord

    International Nuclear Information System (INIS)

    Hirota, Saeko; Yoshida, Shoji; Soejima, Toshinori

    1993-01-01

    Gd-enhanced MR images of two patients with clinically and histopathologically diagnosed chronic progressive radiation myelitis (CPRM) were observed chronologically. One of them had had nasopharyngeal cancer and received radiotherapy at a dose of 100 Gy to the C1-2 level of the spinal cord. She developed CPRM 25 months after the termination of radiotherapy. The other had had malignant lymphoma originating from the tonsil and received chemoradiotherapy. The dose delivered to her cervical spinal cord was 40 Gy, and she developed CPRM 30 months later. Gd-enhanced MRI in the early phase revealed a small crescent-shaped nidus with or without a very small central nonenhanced area in both cases. Enhancement was not great. At that time, patients noticed only the inability to perceive pain and temperature or paresthesia in the opposite side. In a few months, MRI revealed a much more strongly enhanced and larger nidus with enlargement of a central nonenhanced area accompanied by long segmental cord enlargement. The patients' neurological symptoms had also progressed, with hemiparesis developing, for example. (author)

  12. Role of Exchange Equilibria in Structural Chemistry; Role des Equilibres d'Echange en Chimie Structurale; Rol' ravnovesiya obmena v strukturnoj khimii; Papel de los Equilibrios de Intercambio en Quimica Estructural

    Energy Technology Data Exchange (ETDEWEB)

    Van Wazer, J. R.; Moedritzer, K. [Monsanto Company, St. Louis, MI (United States)

    1965-10-15

    revanche, de vastes parties de la chimie inorganique n'ont jamais pu faire l'objet de descriptions parce que les echanges que subissent les molecules sont si rapides que ces molecules ne peuvent etre separees. Toutefois, elles peuvent etre identifiees et dosees par des methodes physiques (par exemple la RMN) ayant des constantes de temps courtes, si les donnees obtenues font l'objet d'un traitement mathematique approprie, ce traitement etant assez complexe pour justifier l'emploi d'un ordinateur a grande vitesse [6, 16]. Les points passes en revue ont ete illustres par des exemples de systemes [2, 12, 24, 28] tires des travaux recents de l'auteur. Outre les etudes d'equilibre, l'attention de l'auteur s'est portee sur la cinetique des processus d'echange [26, 27]. Il a expose plusieurs theoremes de caractere general qui sont utiles pour prevoir les genres et quantites de produits [6, 18]. (author) [Spanish] Si bien gran parte de los estudios realizados hasta el presente sobre las reacciones de intercambio se han dedicado a la introduccion de sustituyentes monofuncionales en atomos o partes de molecula polifuncionales, tambien las moleculas complicadas pueden sufrir un intercambio de partes, para dar una distribucion equilibrada de moleculas de diversos tamanos y formas. En una seria de trabajos originados en el laboratorio Monsanto Co. (veanse las refs.[1-34] al final de los resumenes), durante 1964 y 1965, se describio el empleo de la resonancia magnetica nuclear de elevado poder de resolucion para estudiar esas mezclas en equilibrio. Los sistemas asi estudiados incluyen varias familias nuevas de compuestos, y los tipos de productos resultantes de los intercambios se han definido y sus cantidades se han determinado en funcion de un pequeno numero de constantes de equilibrio. SeJia empleado un nuevo enfoque matematico - la teoria del grafico estocastico [6] - para establecer la ferma y el numero minimo de constantes de equilibrio que vinculan las estructuras aciclicas y las

  13. Resonancias discursivas y cortesía en prácticas de lecto-escritura Ressonâncias discursivas e polidez em práticas de leitura e produção escrita Discursive resonance and politeness in reading and writing practices

    Directory of Open Access Journals (Sweden)

    Silvana SERRANI-INFANTE

    2001-01-01

    Full Text Available Neste artigo, apresentamos um estudo sobre a compreensão em leitura baseado em uma abordagem contrastiva de cunho argumentativo-discursivo. Examinamos a relação materialidade lingüística - processo discursivo, observando a conexão entre a leitura em língua estrangeira próxima (espanhol e a produção escrita e a memória textual em língua materna (português. Além do interesse na pesquisa aplicada e as conseqüências para o ensino-aprendizagem de línguas, investigamos a relação teórica entre língua, subjetividade e discurso, focalizando a questão da polidez. A textualidade é concebida enquanto sedimentação de regularidades discursivas. Essa sedimentação, por ser singular em cada produção textual, não deixa de estar imbricada em uma rede de memórias discursivas, resultantes de relações sociais, contraditórias, em contextos históricos determinados (Foucault, 1986; Pêcheux, 1990. Na experiência de pesquisa aqui apresentada, temos como referência procedimentos da metodologia do Projeto Galatea, desenvolvido na União Européia para estudar a intercompreensão em línguas românicas (Dabène, 1996. Em nosso estudo, utilizamos, também, procedimentos de simulação, com projeção enunciativa dos participantes, e operamos com a noção de ressonância discursiva. Os resultados, que dizem respeito aos modos direto e indireto de enunciar e à polidez enunciativa, levam a concluir que a concepção de polidez deve ser pensada além de fenômeno restrito a estratégia pragmática para evitar conflitos, para passar a ser abordada enquanto marca de constituição identitária e social. Finalmente, salientamos a relevância da sensibilização à discursividade, mostrando implicações teóricas e práticas de sua implementação.In this paper we present a study of reading comprehension based on a contrastive argumentative-discursive approach. We examine the relationship between linguistic materiality and discursive processes, observing the connection between reading in a foreign language, writing production and textual memories in the mother tongue. In addition to an interest in practical language teaching and learning processes (in this case of Spanish and Portuguese, we investigate the question of politeness and the theoretical relationship between subjectivity, language, and textuality. The latter, being understood as the result of discourse regularities, is unique for each and every production, yet is also conditioned by plural discursive memories resulting from contradictory social relationships in a specific historical context (Foucault, 1986; Pêcheux, 1990. In the experiment presented here, we follow some of the procedures of the methodology applied in the European Galatea Project developed for the study of reading strategies in the inter-comprehension between Romance languages (Dabène, 1996. We use the procedure of simulation and the subjective projection of participants as well as the notion of discursive resonance in the analysis. The results, having to do with directness and indirectness in speech and the question of politeness in two typologically close languages, lead to the conclusion that the concept of politeness goes beyond a pragmatic strategy used to avoid conflicts to be approached as a marker of cultural identity constitution. The relevance of discursive awareness and its theoretical and practical consequences are then emphasized.

  14. Study of the K K{pi} meson resonances produced in antiproton proton annihilations at 750 MeV/c; Estudio de resonancias mesonicas en el sistema KK{pi} en aniquilaciones de antiprotones a 750 MeV/cde momento

    Energy Technology Data Exchange (ETDEWEB)

    Gil Lopez, E

    1977-07-01

    In this work we present an analysis of the antiproton proton annihilations into strange particles at 700 and 750 MeV/c, restricted to the four and five body final states. We study in detail the resonances decaying into the K K{pi}; system, in particular the D and E mesons. For the D meson we present a determination of i ts mass, width, isospin, G-parity, C-parity and spin. For the E meson we present parametrizations of the complete final state which decrease its statistical significance in this type of production. (Author)

  15. Study of the association degree between cerebral magnetic resonance signal and the transcranial sonography Estudio del grado de asociación entre la señal de resonancia magnética cerebral y la ecografía transcraneal Estudi del grau d'associació entre el senya de ressonancia magnètica cerebral i l'ecografia transcranial

    OpenAIRE

    Carrascosa Morales, Rafael

    2012-01-01

    El coregistre d'una imatge d'ecografia transcraneal amb un volum de ressonància magnètica cerebral i estudi del grau d'associació entre elles. Projecte el·laborat amb Transmural Biotech SL English: The study tries to achieve a multimodal registration between a transcranial sonography (TCS) and a cerebral magnetic resonance volume. After the registration stage, a statistical analysis of each brain matter (white matter, gray matter and cerebrospinal fluid) was performed to demonstrate the...

  16. Valor de la resonancia magnética con realce tardío de gadolinio en el diagnóstico etiológico de la insuficiencia cardiaca con disfunción sistólica del ventrículo izquierdo

    OpenAIRE

    Soriano Navarro, Carlos Joaquín

    2013-01-01

    La insuficiencia cardiaca constituye un problema de salud y de gestión de los recursos sanitarios de primer orden. Se estima que la prevalencia de insuficiencia cardiaca sintomática en la población general europea oscila entre el 0.4-2%. El diagnóstico preciso del síndrome de insuficiencia cardiaca por medios exclusivamente clínicos es dificultoso y muchas veces inadecuado sobre todo en mujeres, ancianos y obesos20. La insuficiencia cardiaca asociada a miocardiopatía dilatada idiopática o a m...

  17. La Disminución volumétrica del núcleo caudado derecho como fenotipo neuroanatómico del trastorno por déficit de atención con hiperactividad pediátrico un análisis morfométrico fronto-caudado por resonancia magnética estructural /

    OpenAIRE

    Soliva Vila, Juan Carlos

    2007-01-01

    Consultable des del TDX Títol obtingut de la portada digitalitzada Introducción: El trastorno por déficit de atención con hiperactividad (TDAH) es altamente prevalente en la infancia. El paradigma neurobiológico dominante sostiene que la disfunción nuclear del TDAH es un déficit de las funciones ejecutivas, cuyos loci neurobiológicos serían los circuitos fronto-subcorticales descritos por Alexander. Objetivos: Determinar y comparar (1)los volúmenes de las regiones prefrontales y (2) de ...

  18. Caracterización de la deformación miocárdica en pacientes con hipertrofia ventricular izquierda de diferente etiología/nmediante el uso de distribuciones de strain obtenidas de imágenes de resonancia magnética

    OpenAIRE

    Piella Fenoy, Gemma; De Craene, Mathieu; Bijnens, Bart; Tobón Gómez, Catalina, 1981-; Huguet, Marina; Avegliano, G.; Frangi Caregnato, Alejandro

    2010-01-01

    Introducción y objetivos. Se ha señalado que, en la miocardiopatía hipertrófica (MCH), la desorganización de las fibras regionales da lugar a segmentos en los que la deformación es nula o está gravemente reducida, y que estos segmentos tienen una distribución no uniforme en el ventrículo izquierdo (VI). Esto contrasta con lo observado en otros tipos de hipertrofia como en el corazón de atleta o la hipertrofia ventricular izquierda hipertensiva (HVI-HT), en los que puede haber una deformación ...

  19. Study of the influence of the temperature in the magnetic properties and in microstructure in the permanent magnets Pr-Fe-B-Nb-Co based obtained by hydrogen; Estudo da influencia da temperatura nas propriedades magneticas e na microestrutura nos imas permanentes a base de Pr-Fe-B-Nb-Co obtidos com hidrogenio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Suelanny Carvalho da

    2007-07-01

    Fine magnetic powders were produced using the hydrogenation disproportionation desorption and recombination (HDDR) process. The first stage in this work involved an investigation of the effect of the Co content and range of desorption/ recombination temperatures between 800 and 900 deg C with the purpose of optimizing the HDDR treatment for Pr{sub 14}Fe{sub 80}B{sub 6} and Pr{sub 14}Fe{sub bal}Co{sub x}B{sub 6}Nb{sub 0,1} (x= 0, 4, 8, 10, 12, 16) alloys. The cast alloys were annealed at 1100 deg C for 20 hours for homogenization. The processing temperature (desorption/ recombination) affected the microstructure and magnetic properties of the bonded magnets. The alloy with low cobalt content (4 at.%) required the highest reaction temperature (880 deg C) to yield anisotropic bonded magnets. The optimum temperature for alloys with 8 at.% Co and 10 at.% Co were 840 deg C and 820 deg C, respectively. Alloys with high cobalt content (12 at.% and 16 at.%) were processed at 840 deg C. The optimum desorption temperature for achieving high anisotropy for Pr{sub 14}Fe{sub 80}B{sub 6} and Pr{sub 14}Fe{sub 79,9}B{sub 6}Nb{sub 0,1} was 820 deg C. The best remanence (862 mT) was achieved with the Pr{sub 14}Fe{sub 67,9}B{sub 6}Co{sub 12}Nb{sub 0,1} magnet, processed at 840 deg C. Each alloy required an optimum reaction temperature and exhibited a particular microstructure according to the composition. The second stage of the work involved the characterization, for each temperature, of the Pr{sub 14}Fe{sub 80}B{sub 6} HDDR powder processed using X-ray diffraction analysis. The samples of the HDDR material were studied by synchrotron radiation powder diffraction using the Rietveld method for cell refinement, phase quantification and crystallite sizes determination. Scanning electron microscopy has also been employed to reveal the morphology of the HDDR powder. (author)

  20. Milling condition effects on the Nd{sub 15} Fe{sub 77} B{sub 8} powder magnetic properties; Efeito das condicoes de moagem sobre as propriedades magneticas de po de Nd{sub 15} Fe{sub 77} B{sub 8}

    Energy Technology Data Exchange (ETDEWEB)

    Landgraf, Fernando J.G.; Missell, Frank P

    1993-12-31

    As a result of the first part of a study of the development of permanent magnets, an investigation of the effect of milling on the magnetic properties of the alloy Nd{sub 15} Fe{sub 77} B{sub 8} showed differences in efficiency between ball milling and vibration milling, as well as a dependence of the intrinsic coercive field on particle size. The maximum value of the coercive field was obtained for a particle size of 1.7 {mu}m in samples compacted without magnetic orientation. (author) 9 refs., 4 figs.

  1. Evaluation of the magnetic properties of hybrids MnFe{sub 2}O{sub 4}/SiO{sub 2} /chitosan aiming its application as biosensors; Avaliacao das propriedades magneticas de hibridos MnFe{sub 2}O{sub 4}/SiO{sub 2}/quitosana visando sua aplicacao como biosensores

    Energy Technology Data Exchange (ETDEWEB)

    Leal, E.; Santos, P.T. A.; Costa, F.M., E-mail: elvialeal@gmail.com [Universidade Federal de Campina Grande (LabSMaC/UFCG), PB (Brazil). Laboratorio de Sintese de Materiais Ceramicos; Barbosa, D.C. [Universidade Federal de Alagoas (UFAL), Maceio, AL (Brazil). Instituto de Quimica e Biotecnologia; Cornejo, D.R. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia de Materiais

    2014-07-01

    Magnetic nanoparticles have potential application in biomedicine since their features allow a wide variety of applications, such as biosensors, drug carriers, destruction of tumor cells and magnetic separation of cells and proteins. Overlooking that, the proposal is to obtain the hybrid MnFe{sub 2}O{sub 4}/SiO{sub 2}/ chitosan, to evaluate it as its magnetic property, aiming to obtain a biocompatible hybrid for biological applications, such as, e.g., biosensors. The samples were analyzed by XRD, FTIR, SEM and magnetic measurements. The results revealed that the samples of pure MnFe{sub 2}O{sub 4}, silanized and with chitosan presented the formation of the spinel with crystallite sizes of 77, 80 and 79 nm, respectively. The FTIR spectra confirmed the presence of characteristic absorption bands of the spinel and groups present in silanol and chitosan, confirming the formation of the hybrid. The silane introduction kept the ferrimagnetic characteristic of the material and led to a slight increase in the saturation magnetization, going from 55 to 61 emu/g. (author)

  2. Fluorescein isothiocyanate labeled, magnetic nanoparticles conjugated D-penicillamine-anti-metadherin and in vitro evaluation on breast cancer cells; Avaliacao do isotiocianato de fluoresceina marcado, das nanoparticulas magneticas conjugadas da D-penicilamina antimetaderina e in vitro nas celulas do cancer de mama

    Energy Technology Data Exchange (ETDEWEB)

    Akca, Ozlet; Unak, Perihan; Medine, E. Ylker [Ege University (Turkey). Institute of Nuclear Sciences. Department of Nuclear Applications; Sakarya, Serhan [Adnan Menderes University (Turkey). ADUBILTEM Science and Technology Research and Development Center; Ozdemir, Caglar; Timur, Suna [Ege University (Turkey). Science Faculty. Department of Nuclear Applications

    2011-07-01

    Silane modified magnetic nanoparticles were prepared after capped with silica generated from the hydrolyzation of tetraethyl orthosilicate (TEOS). Amino silane (SG-Si900) was added to this solution for surface modification of silica coated magnetic particles. Finally, D-penicillamine (D-PA)-antimetadherin (anti-MTDH) was covalently linked to the amine group using glutaraldehyde as cross-linker. Magnetic nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and atomic force microscopy (AFM). AFM results showed that particles are nearly monodisperse, and the average size of particles was 40 to 50 nm. An amino acid derivative D-PA was conjugated anti-MTDH, which results the increase of uptaking potential of a conjugated agent, labelled fluorescein isothiocyanate (FITC) and then conjugated to the magnetic nanoparticles. In vitro evaluation of the conjugated D-PA-anti-MTDH-FITC to magnetic nanoparticle was studied on MCF-7 breast cancer cell lines. Fluorescence microscopy images of cells after incubation of the sample were obtained to monitor the interaction of the sample with the cancerous cells. Incorporation on cells of FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH was found higher than FITC labeled D-PA-anti-MTDH. The results show that magnetic properties and application of magnetic field increased incorporation rates. The obtained D-PA-anti-MTDH-magnetic nanoparticles-FITC complex has been used for in vitro imaging of breast cancer cells. FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH may be useful as a new class of scintigraphic agents. Results of this study are sufficiently encouraging to bring about further evaluation of this and related compounds for ultraviolet magnetic resonance (UV-MR) dual imaging. (author)

  3. Whole-body magnetic resonance imaging for staging and follow-up of pediatric patients with Hodgkin's lymphoma: comparison of different sequences; Aplicacao da ressonancia magnetica de corpo inteiro para o estadiamento e acompanhamento de pacientes com linfoma de Hodgkin na faixa etaria infanto-juvenil: comparacao entre diferentes sequencias

    Energy Technology Data Exchange (ETDEWEB)

    Nava, Daniel; Oliveira, Heverton Cesar de, E-mail: daniel@centrus.com.b [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem; Luisi, Flavio Augusto; Lederman, Henrique Manoel [Universidade Federal de Sao Paulo (UNIFESP/IOP/GRAACC), SP (Brazil). Inst. de Oncologia Pediatrica. Grupo de Apoio ao Adolescente e a Crianca com Cancer; Ximenes, Andrea Regina da Silveira [Clinica Centrus, Campinas, SP (Brazil)

    2011-07-01

    Objective: to compare the performance of the T1, T2, STIR and DWIBS (diffusion-weighted whole-body imaging with background body signal suppression) sequences in the staging and follow-up of pediatric patients with Hodgkin's lymphoma in lymph node chains, parenchymal organs and bone marrow, and to evaluate interobserver agreement. Materials and methods: the authors studied 12 patients with confirmed diagnosis of Hodgkin's lymphoma. The patients were referred for whole body magnetic resonance imaging with T1-weighted, T2-weighted, STIR and DWIBS sequences. Results: the number of lymph node sites characterized as affected by the disease on T1- and T2-weighted sequences showed similar results (8 sites for both sequences), but lower than DWIBS and STIR sequences (11 and 12 sites, respectively). The bone marrow involvement by lymphoma showed the same values for the T1-, T2-weighted and DWIBS sequences (17 lesions), higher than the value found on STIR (13 lesions). A high rate of interobserver agreement was observed as the four sequences were analyzed. Conclusion: STIR and DWIBS sequences detected the highest number of lymph node sites characterized as affected by the disease. Similar results were demonstrated by all the sequences in the evaluation of parenchymal organs and bone marrow. A high interobserver agreement was observed as the four sequences were analyzed. (author)

  4. Thermal treatment of the Fe{sub 78} Si{sub 9} B{sub 13} alloy and the analysis of it magnetic properties through Moessbauer spectroscopy and Positronium annihilation; Tratamiento termico de la aleacion Fe{sub 78} Si{sub 9} B{sub 13} y el analisis de sus propiedades magneticas mediante Espectroscopia de Moessbauer y Aniquilacion de positronio

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, A

    2005-07-01

    The present work is divided in five chapters. In the first one a general vision of the amorphous alloys is given from antecedents, structure, obtaining methods, properties and problems that at the moment, focusing us in a certain moment to the iron base alloys and the anomalous problem of hardness that it presents the alloy Fe{sub 78}Si{sub 9}B{sub 13} like previously mention us. The second chapter tries on the basic theory of the techniques of Moessbauer spectroscopy and Positron Annihilation spectroscopy, used for the characterization of our alloy as well as the complementary technique of X-ray diffraction (XRD) to observe that the amorphous phase was even studying. The third chapter describes the experimental conditions that were used to study the alloy Fe{sub 78}Si{sub 9}B{sub 13} in each one of their thermal treatments. In the fourth chapter the obtained results and their discussion are presented. In the fifth chapter the conclusions to which were arrived after analyzing the results are presented. (Author)

  5. Usefulness of magnetic resonance cholangiography in the diagnosis of biliary tract lesions in patients with suspected complication following cholecystectomy; Valor da colangiopancreatografia por ressonancia magnetica no diagnostico de lesoes das vias biliares em pacientes com suspeita de complicacao pos-colecistectomia

    Energy Technology Data Exchange (ETDEWEB)

    Cecin, Alexandre de Oliveira [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil); Goldman, Suzan Menasce; Caetano, Simone; Rosas, George de Queiroz; Coelho, Rafael Darahem de Souza [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem; Lobo, Edson Jose [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Gastroenterologia Cirurgica; Abdalla, Nitamar; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem

    2005-01-15

    Objective: to determine the usefulness of magnetic resonance cholangiopancreatography (MRCP) in the diagnoses of bile duct injuries following cholecystectomy. Material and method: MRCP was retrospectively evaluated in 40 patients with suspected bile duct injury after laparoscopic or conventional cholecystectomy. Eight of these patients had been submitted to biliary reconstruction. All patients were symptomatic (jaundice, fever and chills, weight loss and abdominal pain). The scans were independently reviewed by two radiologists. The results were confirmed by surgery, percutaneous drainage, endoscopic retrograde cholangiopancreatography and clinical follow-up. The level and severity of bile duct injury were rated according to the Bismuth classification. Results: in a total of 40 symptomatic patients, 10 (25%) had normal findings on MRCP; Postoperative complications were seen in 29 (72.5%) patients, seven of them with more than one finding. Pancreatic head neoplasia was diagnoses in one patient. The most frequent finding was sclerosing (41.4%) followed by biliary duct stenosis (34.5%), residual or recurrent biliary stones (31.0%) and fluid collections (17.2%). The images obtained by MRCP were considered of good quality. Conclusion: MRCP is an effective method for the evaluation of patients with suspected postcholecystectomy biliary tract complications. (author)

  6. Homogeneity characterization of ethylene-co-vinyl acetate copolymer (EVA) and hydrophobic silica nanocomposite by low field NMR; Caracterizacao da homogeneidade de nanocomposito do copolimero etileno acetato de vinila (EVA) e silica hidrofobica atraves de ressonancia magnetica nuclear de baixo campo

    Energy Technology Data Exchange (ETDEWEB)

    Stael, Giovanni Chaves [Observatorio Nacional, Rio de Janeiro, RJ (Brazil). Dept. de Geofisica (DGE); Tavares, Maria I.B. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas

    2005-07-01

    This project proposes the characterization of a polymeric matrix composite material using nanometric scale hydrophobic silica as charge element, with the ethylene-vinyl acetate (EVA), by using the spin-lattice relaxation time measurement applying the low field NMR.

  7. Algorithm for three dimension reconstruction of magnetic resonance tomographs and X-ray images based on Fast Fourier Transform; Algoritmo para reconstrucao tridimensional de imagens de tomografos de ressonancia magnetica e de raio-X baseado no uso de Transformada Rapida de Fourier

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Josiane M.; Traina, Agma Juci M. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Ciencias Matematicas; Cruvinel, Paulo E. [EMBRAPA, Sao Carlos, SP (Brazil). CNPDIA

    1995-12-31

    This work presents an algorithm for three-dimensional digital image reconstruction. Such algorithms based on the combination of both a Fast Fourier Transform method with Hamming Window and the use of a tri-linear interpolation function. The algorithm allows not only the generation of three-dimensional spatial spin distribution maps for Magnetic Resonance Tomography data but also X and Y-rays linear attenuation coefficient maps for CT scanners. Results demonstrates the usefulness of the algorithm in three-dimensional image reconstruction by doing first two-dimensional reconstruction and rather after interpolation. The algorithm was developed in C++ language, and there are two available versions: one under the DOS environment, and the other under the UNIX/Sun environment. (author) 10 refs., 5 figs.

  8. Uncommon evolution of probable central nervous system histoplasmosis: from leptomeningitis to posterior fossa granuloma. A case report with magnetic resonance images; Evolucao incomum de provavel histoplasmose de sistema nervoso central: de leptomeningite para granuloma da fossa posterior. Relato de caso com imagens por ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Carrilho, Paulo Eduardo Mestrinelli; Alves, Orival [Universidade Estadual do Oeste do Parana - UNIOESTE, Cascavel, PR (Brazil). Curso de Medicina. Disciplina de Neurologia e Neurocirurgia]. E-mail: carrilho@certto.com.br; Budant, Manfredo [UNITOM - Unidade de Diagnostico por Imagem, Cascavel, PR (Brazil). Centro de Tomografia; Bozo, Marlon K.; Meirelles, Noel [Universidade Estadual do Oeste do Parana - UNIOESTE, Cascavel, PR (Brazil). Curso de Medicina; Bueno, Alexandre Galvao [ANATOM - Instituto de Anatomia Patologica de Cascavel, PR (Brazil)

    2006-01-15

    We report a case of a young immunocompetent patient with probable central nervous system histoplasmosis with evolutive peculiar findings seen on magnetic resonance imaging. Leptomeningeal thickening was initially observed which subsequently became a posterior fossa granuloma. The diagnosis of fungal infection was only reached by histopathological study and the treatment was based on long term therapy with fluconazole wth good initial response. (author)

  9. Relations microstructure - magnetic properties - squareness factor of PrFeB and NdFeB sintered magnets prepared with hydrogen; Estudo das correlacoes entre microestrutura, propriedades magneticas e fator de quadratura em imas sinterizados de PrFeB e NdFeB processados com hidrogenio

    Energy Technology Data Exchange (ETDEWEB)

    Perigo, Elio Alberto

    2009-07-01

    In this work, it has firstly been evaluated the preparation of Pr{sub 16}Fe{sub 76}B{sub 8} sintered permanent magnets (% at.) by means of high-energy milling using a planetary ball mill. The influence of both milling speed and time has been verified. The best magnetic properties [J{sub R} = (1.02 {+-} 0.02) T, {mu}{sub 0J}H{sub c} = (1.42 {+-} 0.03) T and (BH){sub max} = (200 {+-} 4) kJm{sup -3}] have been found for a permanent magnet prepared with the magnetic alloy milled during 75 minutes using a rotational milling speed of 200 rpm. In order to improve the remanence, the hydrogen decrepitation process time has been reduced from 60 minutes to 2 minutes. In this case, it has been obtained a sintered magnet with J{sub R} = (1.14 {+-} 0.02) T, {mu}{sub 0J}H{sub c} = (1.44 {+-} 0.03) T and (BH){sub max} = (250 {+-} 5) kJm{sup -3} due to the improvement of crystallographic alignment of the hard magnetic phase. During such investigation, a new methodology to quantify the parameter has been developed. Subsequently, for the first time, a quantitative correlation between the microstructure and the squareness factor in anisotropic sintered RE{sub 16}Fe{sub 76}B{sub 8} (RE = Nd or Pr) magnets has been proposed. The presented expression utilizes the mean size, the mean elongation and the mean roundness of the hard magnetic grains as well as their respective standard deviations. The squareness factor can be improved with a microstructure with rounder grains and with a sharp grain size distribution. The grain size homogeneity is more important to enhance the squareness factor compared to grain shape homogeneity. Furthermore, it has also been verified that the annealing after sintering improves the grain shape homogeneity and the milling enhances the grain size homogeneity. Moreover, the effect of the temperature on the squareness factor of anisotropic sintered magnets has also been evaluated. Such parameter is mainly controlled by the sample's microstructure, in agreement with the proposed expression. Furthermore, a quantitative correlation between the maximum energy product and the squareness factor has been proposed. Experimental and calculated values have been compared and the discrepancy found has been, in general, inferior to 5%. At last, the minimum squareness factor value of sintered permanent magnets has also been evaluated. Isotropic samples should show the smallest squareness factor due to the reduced degree of crystallographic alignment. In general, for this kind of sample, 0.20 {<=} SF {<=} 0.30. (author)

  10. The possibility of recurrent selection to increase the oil content in soybeans using genetic male sterility and NMR spectroscopy; Possibilidade de selecao recorrente para aumento do teor de oleo em soja com a utilizacao da macho-esterilidade genetica e da espectroscopia de ressonancia nuclear magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, M A.C. de; Teixeira, J P.F.; Mascarenhas, H A.A. [Instituto Agronomico de Campinas, SP (Brazil); Rettori, C [Universidade Estadual de Campinas, SP (Brazil). Inst. de Fisica

    1990-12-31

    The seed oil content of male sterile plants and their progenies was analysed by a NMR spectroscope to study the possibility of recurrent selection to improve the oil content. The results suggest the possibility of recurrent selection in the composite IAC-1 both in the field with male sterile plants or at the greenhouse when selection is based on average values of progenies. 30 refs., 3 figs., 3 tabs.

  11. Study using {sup 1} H and {sup 13} V NMR of 3-aryl-s-triazole benzoate azole type compounds and intermediaries; Estudo por ressonancia magnetica nuclear de {sup 1} H e {sup 13} C compostos do tipo 3-aril-s-triazolo benzotiazol e seus intermediarios

    Energy Technology Data Exchange (ETDEWEB)

    Garske, Jose Emilio L; Bacha, Catarina T.M.; Schenkel, Eloir Paulo [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Faculdade de Farmacia

    1992-12-31

    Approximately 62% of the compounds used for medical purposes are heterocyclic, and are distributed as follows: 95% containing hydrogen, 28% containing sulfur and 18% containing oxygen in the structural composition. Some triazole-s-triazole type hetero aromatic systems and intermediaries, such as 1-aryl hydrazides exhibited bactericide, anti inflammatory and fungi stat activities. All the triazoles are are obtained synthetically, and are not found in the Nature. The proton and carbon-13 spectra of the non usual I, II and III compounds that we obtained are discussed in this work 8 refs., 3 figs.

  12. Study of amorphous semiconductors doped with rare earths (Gd and Er) and conducting polymers by EPR techniques and magnetic susceptibility; Estudo de semicondutores amorfos dopados com terras raras (Gd e Er) e de polimeros condutores atraves das tecnicas de RPE e susceptibilidade magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Sercheli, Mauricio da Silva

    1999-07-01

    This thesis involves the study of amorphous semiconductors and conducting polymers, which have been characterized by EPR and magnetic susceptibility measurements, and to a lesser extent by Raman spectroscopy and RBS. The semiconductors were studied using thin films of silicon doped with rare earth metals, e.g. erbium and gadolinium, which had their magnetic properties studied. Using these studies we could determine the state of valence of the rare earths as well as their concentrations in the silicon matrix. According to our results, the valence of the rare earth metal ions is 3+, and we were able to conclude that 4f electronic shells could not be used for the calculation of the conducting band in this system. Furthermore, the analysis of the data on the magnetic susceptibility of the Er{sup 3+} ion with cubic crystalline acting field, gave us the opportunity to estimate the overall splitting of their electronic states for the first time. The conducting polymers were studied using samples of poly(3-methylthiophene) doped with ClO{sub 4}{sup -}, which show a phase transition in the range of 230 K to 130 K. The electron paramagnetic resonance also gives important information on the crystallization, doping level and the presence of polarons or bipolarons in conducting polymers. (author)

  13. Synthesis and characterization of magnetic cobalt ferrite nanoparticles covered with 3-aminopropyltriethoxysilane for use as hybrid material in nano technology; Sintese e caracterizacao de nanoparticulas magneticas de ferrita de cobalto recobertas por 3-aminopropiltrietoxissilano para uso como material hibrido em nanotecnologia

    Energy Technology Data Exchange (ETDEWEB)

    Camilo, Ruth Luqueze

    2006-07-01

    Nowadays with the appear of nano science and nano technology, magnetic nanoparticles have been finding a variety of applications in the fields of biomedicine, diagnosis, molecular biology, biochemistry, catalysis, etc. The magnetic functionalized nanoparticles are constituted of a magnetic nucleus, involved by a polymeric layer with active sites, which ones could anchor metals or selective organic compounds. These nanoparticles are considered organic inorganic hybrid materials and have great interest as materials for commercial applications due to the specific properties. Among the important applications it can be mentioned: magneto hyperthermia treatment, drugs delivery in specific local of the body, molecular recognition, biosensors, enhancement of nuclear magnetic resonance images quality, etc. This work was developed in two parts: 1) the synthesis of the nucleus composed by superparamagnetic nanoparticles of cobalt ferrite and, 2) the recovering of nucleus by a polymeric bifunctional 3-aminopropyltriethoxysilane. The parameters studied in the first part of the research were: pH, hydroxide molar concentration, hydroxide type, reagent order of addition, reagent way of addition, speed of shake, metals initial concentrations, molar fraction of cobalt and thermal treatment. In the second part it was studied: pH, temperature, catalyst type, catalyst concentration, time of reaction, relation ratios of H{sub 2}O/silane, type of medium and the efficiency of the recovering regarding to pH. The products obtained were characterized using the following techniques X-ray powder diffraction (DRX), transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), spectroscopy of scatterbrained energy spectroscopy (DES), atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA/DTGA), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and magnetization curves (VSM). (author)

  14. Predictive values of Bi-Rads categories 3, 4 and 5 in non-palpable breast masses evaluated by mammography, ultrasound and magnetic resonance imaging; Valores preditivos das categorias 3, 4 e 5 do sistema Bi-Rads em lesoes mamarias nodulares nao-palpaveis avaliadas por mamografia, ultra-sonografia e ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Roveda Junior, Decio; Fleury, Eduardo de Castro Faria [Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Faculdade de Ciencias Medicas. Servico de Diagnostico por Imagem]. E-mail: decio.jr@uol.com.br; Piato, Sebastiao [Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Dept. de Obstetricia e Ginecologia. Clinica Ginecologica; Oliveira, Vilmar Marques de [Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Dept. de Obstetricia e Ginecologia. Ginecologia Geral; Rinaldi, Jose Francisco [Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Dept. de Obstetricia e Ginecologia. Clinica de Mastologia; Ferreira, Carlos Alberto Pecci [Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Faculdade de Ciencias Medicas. Dept. de Clinica Medica. Servico de Imagenologia Mamaria

    2007-03-15

    Objective: To evaluate the predictive value of BI-RADS{sup TM} categories 3, 4 and 5 in non-palpable breast masses assessed by mammography, ultrasound and magnetic resonance imaging. Materials And Methods: Twenty-nine patients with BI-RADS categories 3, 4 and 5 non-palpable breast masses identified by mammograms were submitted to complementary ultrasound and magnetic resonance imaging studies, besides excisional biopsy. In total, 30 biopsies were performed. The lesions as well as their respective BI-RADS classification into 3, 4 and 5 were correlated with the histopathological results. The predictive values calculation was made by means of specific mathematical equations. Results: Negative predictive values for category 3 were: mammography, 69.23%; ultrasound, 70.58%; and magnetic resonance imaging, 100%. Positive predictive values for category 4 were: mammography, 63.63%; ultrasound, 50%; and magnetic resonance imaging, 30.76%. For category 5, positive predictive values were: mammography and ultrasound, 100%; and magnetic resonance imaging, 92.85%. Conclusion: For category 3, the negative predictive value of magnetic resonance imaging was high, and for categories 4 and 5, the positive predictive values of the three modalities were moderate. (author)

  15. Application of magnetic nanoparticle MnFe{sub 2}O{sub 4} type as a catalyst in esterification reaction; Aplicacao de nanoparticula magnetica do tipo MnFe{sub 2}O{sub 4} como catalisador em reacao de esterificacao

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, K.R. de O.; Barros, A.B. de S.; Moura, T.F.B. de; Vilar, E.; Dantas, J.; Costa, A. C. F. de M., E-mail: klebersonric@gmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Laboratorio de Sintese de Materiais Ceramicos

    2016-07-01

    The interest in obtaining renewable energy arouses the interest of researchers in the development of biofuels to replace conventional fuels. This work aimed to obtain magnetic nanoparticle MnFe{sub 2}O{sub 4} and evaluate their performance as a catalyst in esterification reaction to obtain biodiesel. The sample was synthesized through the combustion reaction and characterized by XRD, SEM and BET. The esterification reaction, the methyl ethyl route was conducted in a high pressure reactor at 180 ° C for 1 hour with oil molar ratio 1:12 alcohol with 2% catalyst. The results indicate the formation of the phase MnFe{sub 2}O{sub 4} and agglomerate in the form of irregular plate, with particles bound strongly to the surface of the agglomerates. The catalytic tests showed that sample was active for the reaction of esterification methyl ethyl route, with conversions of 52% and 48%, respectively. (author)

  16. A study of the process of Nd{sub 15} Fe{sub 77} B{sub 8} magnetic alloy preparation by calciothermic reduction diffusion (R/D); Estudo do processo de obtencao da liga magnetica Nd{sub 15} Fe{sub 77} B{sub 8} por reducao-difusao (R/D) calciotermica

    Energy Technology Data Exchange (ETDEWEB)

    Graca Guilherme, Eneida da; Paschoal, Jose O.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1992-12-31

    In this work the manufacturing of Nd{sub 15}, Fe{sub 77}, B{sub 8} alloy powder for high-performance permanent magnets by reduction-diffusion process was investigated. The effect of variables such as the excess amount of neodymium oxide, the removal of calcium oxide by selective leaching and milling of alloy was examined. (author). 8 refs., 8 figs., 5 tab.s.

  17. Studies concerning the interaction between local anesthetics and lipid membrane by phosphorus-31, deuterium and proton NMR; Estudo da interacao entre anestesicos locais e membranas lipidicas por ressonancia magnetica de fosforo ({sup 31} P), deuterio ({sup 2} H) e proton ({sup 1} H)

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Eneida de [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Dept. de Bioquimica; Jarrell, Harold C. [National Research Council of Canada, Ottawa, ON (Canada). Inst. for Biological Sciences; Schreier, Shirley [Sao Paulo Univ., SP (Brazil). Inst. de Quimica

    1993-12-31

    Local anesthetics block the conduction of nervous stimulus by impeding the entrance of sodium ion and the consequently depolarization of the nervous membrane. The action mechanism of local anesthetics, however, is not fully understood yet. In the present work the interaction between local anesthetics and membranes are studied by the perspective of lipid phase perturbation using NMR to elucidate the mechanism. Results are presented and discussed 5 refs., 1 fig., 1 tab.

  18. Local anesthetics: interaction with human erythrocyte membranes as studied by {sup 1}H and {sup 31}P nuclear magnetic resonance; Anestesicos locais: interacao com membranas de eritrocitos de sangue humano, estudada por ressonancia magnetica nuclear de {sup 1}H e {sup 31}P

    Energy Technology Data Exchange (ETDEWEB)

    Fraceto, Leonardo Fernandes; Paula, Eneida de [Universidade Estadual de Campinas, SP (Brazil). Inst. de Biologia. Dept. de Bioquimica]. E-mail: depaula@unicamp.br

    2004-02-01

    The literature carries many theories about the mechanism of action of local anesthetics (LA). We can highlight those focusing the direct effect of LA on the sodium channel protein and the ones that consider the interaction of anesthetic molecules with the lipid membrane phase. The interaction between local anesthetics and human erythrocyte membranes has been studied by {sup 1}H and {sup 31}P nuclear magnetic resonance spectroscopy. It was found that lidocaine (LDC) and benzocaine (BZC) bind to the membranes, increase the mobility of the protons of the phospholipids acyl chains, and decrease the mobility and/or change the structure of the polar head groups. The results indicate that lidocaine molecules are inserted across the polar and liquid interface of the membrane, establishing both electrostatic (charged form) and hydrophobic (neutral form) interactions. Benzocaine locates itself a little deeper in the bilayer, between the interfacial glycerol region and the hydrophobic core. These changes in mobility or conformation of membrane lipids could affect the Na{sup +}-channel protein insertion in the bilayer, stabilizing it in the inactivated state, thus causing anesthesia. (author)

  19. Comparative study of fast T 2-weighted images using respiratory triggered, breath-hold, fat suppression and phased array multi coil for liver evaluation by magnetic resonance imaging; Estudo comparativo das sequencias rapidas ponderadas em T2, utilizando-se sincronizacao respiratoria, apneia, supressao de gordura, bobina de corpo e bobina de sinergia para a avaliacao do figado pela ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Abbehusen, Cristiane L.; D' Ippolito, Giuseppe; Palacio, Glaucia A.S.; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina (EPM). Dept. de Diagnostico por Imagem]. E-mail: cabbehusen@hotmail.com

    2003-10-01

    The objective of this study was to compare both qualitatively and quantitatively six T 2-weighted turbo spin-echo sequences varying the respiratory compensation technique, associating or not fat tissue suppression and using different types of coils. We performed a prospective study of 71 consecutive patients that were submitted to MRI of the liver using a 1.5 T magnet. The six following pulse sequences were used: fat-suppressed respiratory triggered with conventional body coil; breath-hold fat-suppressed with conventional body coil; non-suppressed respiratory triggered with conventional body coil; breath-hold non fat-suppressed with conventional body coil; fat-suppressed respiratory triggered with phased-array multi coil; breath-hold fat-suppressed with phased-array multi coil. Images were analyzed quantitatively by measuring the signal-to-noise ratios and qualitatively by evaluating the sharpness of hepatic contours, visibility of intrahepatic vessels and other segmental landmarks, and the presence of artifacts. Results: the qualitative analysis showed that the mean values obtained with the six sequences were 7.8, 4.6, 7.9, 5.2, 6.7 and 4.6 respectively. The respiratory-triggered sequences were better than the breath-hold sequences in both qualitative and quantitative analysis (p < 0.001). No significant differences in the values of signal-to-noise ratios and in overall image quality were found between the sequences with and without fat suppression (p . 0.05). The sequences using the body coil were similar in terms of image quality (p . 0.05) and better regarding signal-to-noise ratios than those obtained with the phased=array multi coil (p ,0.001). Our qualitative and quantitative results suggest that the best MRI sequences for the valuation of the liver are the sequences with respiratory triggering using a conventional body coil, with or without fat suppression. (author)

  20. Evaluation of agreement between transvaginal ultrasonography and magnetic resonance imaging of the pelvis in deep endometriosis with emphasis on intestinal involvement; Avaliacao da concordancia entre a ultrassonografia transvaginal e a ressonancia magnetica da pelve na endometriose profunda, com enfase para o comprometimento intestinal

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Maene Marcondes; Coutinho Junior, Antonio Carlos; Domingues, Marisa Nassar Aidar [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil)], e-mail: maenemc@oi.com.br; Werner Junior, Heron [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil). Unit of Gynecologic/Obstetric Radiology; Berardo, Plinio Tostes [Universidade Estacio de Sa, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina; Gasparetto, Emerson Leandro [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia; Domingues, Romeu Cortes [Clinicas Multi-Imagem, Rio de Janeiro, RJ (Brazil)

    2009-03-15

    Objective: To compare sonographic and magnetic resonance imaging findings in deep endometriosis with emphasis on intestinal involvement. Materials and methods: Eighteen women aged between 23 and 49 years with clinical suspicion and gynecological signs suggestive of deep endometriosis were submitted to ultrasonography and magnetic resonance imaging for correlation between findings. Results: Ultrasonography detected 40 lesions while magnetic resonance imaging detected 53 lesions in the pelvis. A comparative study has not shown any statistically significant intermethod difference in the detection of lesions (respectively p > 0.19 and p > 0.14). In the rectosigmoid junction, magnetic resonance imaging has detected one (5.6%) lesion, while ultrasonography has detected four lesions (22.2%). In the rectum, ultrasonography has detected eight lesions (44.4%), and magnetic resonance imaging has detected seven lesions (38.9%). Conclusion: The intermethod agreement has not been good for lesions in the rectosigmoid junction, considering that ultrasonography has detected a higher number of lesions in this region, but a lower number of lesions in the pelvis as compared with magnetic resonance imaging. The global comparative analysis has demonstrated no statistically significant intermethod difference in the detection of lesions. Low cost, good tolerability and high availability make ultrasonography a valuable diagnostic tool in cases of deep endometriosis. (author)

  1. Control optimo de par para maquinas SynRM aplicadas a vehiculo electrico

    OpenAIRE

    Trancho, Elena; Ibarra, E.; Arias, A.; Kortabarria, I.

    2017-01-01

    Las maquinas de reluctancia sincrona asistidas por imanes estan atrayendo un considerable interes como alternativa a las maquinas sıncronas de imanes permanentes para su uso en sistemas de propulsion de vehıculos electricos. El control optimo de estas maquinas (incluyendo operacion en debilitamiento de campo) puede resultar complejo, ya que estas son, por lo general, muy sensibles al fenomeno de la saturacion magnetica. En este articulo se trata su control, desde los reguladores hasta el prec...

  2. Il nucleo terrestre: il cuore magnetico della Terra

    OpenAIRE

    De Santis, A.

    2006-01-01

    Il campo magnetico terrestre è una proprietà intrinseca del nostro pianeta e di altri oggetti del sistema solare. Il Sole stesso possiede un forte campo magnetico che si inverte quasi ciclicamente ogni 10-11 anni; tale comportamento è visibile attraverso la medesima ciclicità delle macchie solari che denotano sulla superficie l’intensa attività magnetica della nostra stella. Il campo magnetico terrestre è importantissimo per la vita sulla Terra. Esso protegge il pianeta dalle p...

  3. Structural and Magnetic Studies on Iron Oxide Nanoparticles in Hybrid Matrices =

    Science.gov (United States)

    Silva, Nuno Joao de Oliveira

    Este trabalho aborda algumas propriedades magneticas e estruturais de nanoparticulas de oxidos e oxidos-hidroxidos de ferro crescidos em matrizes hibridas orgânicas-inorgânicas. As matrizes hibridas, denominadas di-ureasils e obtidas pelo processo sol-gel, sao compostas por uma rede siliciosa ligada covalentemente por pontes ureia a cadeias orgânicas de diferente peso molecular. A estrutura local dos di-ureasils nao dopados esta modelada como grupos de dominios siliciosos com dimensoes nanometricas, estruturalmente correlacionados no seio de uma matriz rica em polimero. Neste trabalho mostra-se que os di-ureasils permitem o crescimento controlado de oxidos e oxidos-hidroxidos de ferro, incluindo a magnetite, maguemite, oxihidroxinitrato de ferro e ferrihidrite. O crescimento das nanoparticulas de ferrihidrite da-se em condicoes acidas a superficie dos dominios siliciosos, junto aos grupos carbonilo, que funcionam como pontos de nucleacao. Desse modo da-se uma nucleacao heterogenea, onde o tamanho das nanoparticulas depende da concentracao de ferro (entre 1 e 6% em massa), sendo a concentracao de particulas constante. As propriedades magneticas das nanoparticulas de ferrihidrite revelam a existencia de interaccoes antiferromagneticas e de momentos descompensados. A contribuicao destas duas componentes nas curvas de magnetizacao em funcao do campo magnetico pode ser separada usando um metodo aqui proposto, o que permite um adequado estudo da evolucao do momento magnetico com a temperatura. O estudo das propriedades magneticas dinâmicas das particulas de ferrihidrite, atraves de susceptibilidade ac, medidas de relaxacao e medidas de efeito Mossbauer, permitiu estudar a evolucao das interaccoes dipolares em funcao da concentracao de ferro, bem como determinar a distribuicao de barreiras de energia de anisotropia no caso em que essas interaccoes sao desprezaveis. E apresentado um novo metodo para comparacao desta distribuicao com a distribuicao de tamanhos, que

  4. Spin-Transfer-Torque Nano-Oscillators: Fabrication, Characterization and Dynamics

    Science.gov (United States)

    Costa, Jose Diogo Teixeira Barbosa

    Este trabalho aborda algumas propriedades magneticas e estruturais de nanoparticulas de oxidos e oxidos-hidroxidos de ferro crescidos em matrizes hibridas orgânicas-inorgânicas. As matrizes hibridas, denominadas di-ureasils e obtidas pelo processo sol-gel, sao compostas por uma rede siliciosa ligada covalentemente por pontes ureia a cadeias orgânicas de diferente peso molecular. A estrutura local dos di-ureasils nao dopados esta modelada como grupos de dominios siliciosos com dimensoes nanometricas, estruturalmente correlacionados no seio de uma matriz rica em polimero. Neste trabalho mostra-se que os di-ureasils permitem o crescimento controlado de oxidos e oxidos-hidroxidos de ferro, incluindo a magnetite, maguemite, oxihidroxinitrato de ferro e ferrihidrite. O crescimento das nanoparticulas de ferrihidrite da-se em condicoes acidas a superficie dos dominios siliciosos, junto aos grupos carbonilo, que funcionam como pontos de nucleacao. Desse modo da-se uma nucleacao heterogenea, onde o tamanho das nanoparticulas depende da concentracao de ferro (entre 1 e 6% em massa), sendo a concentracao de particulas constante. As propriedades magneticas das nanoparticulas de ferrihidrite revelam a existencia de interaccoes antiferromagneticas e de momentos descompensados. A contribuicao destas duas componentes nas curvas de magnetizacao em funcao do campo magnetico pode ser separada usando um metodo aqui proposto, o que permite um adequado estudo da evolucao do momento magnetico com a temperatura. O estudo das propriedades magneticas dinâmicas das particulas de ferrihidrite, atraves de susceptibilidade ac, medidas de relaxacao e medidas de efeito Mossbauer, permitiu estudar a evolucao das interaccoes dipolares em funcao da concentracao de ferro, bem como determinar a distribuicao de barreiras de energia de anisotropia no caso em que essas interaccoes sao desprezaveis. E apresentado um novo metodo para comparacao desta distribuicao com a distribuicao de tamanhos, que

  5. Avances en las técnicas ecográficas para el diagnóstico y estadiaje del cáncer de próstata. Elastografía, ecografía doppler, contrastes ecográficos, métodos de cuantificación ecográfica y fusión con resonancia magnética nuclear

    NARCIS (Netherlands)

    Westendarp, M.; Postema, A.; de la Rosette, J.J.M.C.; Wijkstra, H.; Laguna, M.P.

    OBJECTIVES: Transrectal ultrasound-guided prostate biopsy remains the gold standard in the diagnosis of prostate cancer. Various Ultrasound modalities have been proposed to increase the cancer detection rate. Our purpose is to evaluate each of these methods , and to present its current literature

  6. Avances en las Técnicas Ecográficas para el diagnóstico y estadiaje del cáncer de próstata. Elastografía, Ecografía doppler, Contrastes Ecográficos, Métodos de Cuantificación ecográfica y fusión con Resonancia Magnética Nuclear

    NARCIS (Netherlands)

    Westendarp, M.; Postema, A.; de la Rosette, J. J. M. C.; Wijkstra, H.; Laguna, M. P.

    2015-01-01

    Transrectal ultrasound-guided prostate biopsy remains the gold standard in the diagnosis of prostate cancer. Various Ultrasound modalities have been proposed to increase the cancer detection rate. Our purpose is to evaluate each of these methods , and to present its current literature and clinical

  7. Effect of magnetic resonance imaging on near visual acuity

    OpenAIRE

    MOLINA BETANCUR, CARLOS ANDRÉS; ARBELÁEZ MEDINA, ANDRÉS IGNACIO; MOLINA BETANCUR, MERCEDES CECILIA; AGUDELO, LUZ MARINA; DONADO GÓMEZ, JORGE HERNANDO; VERGARA, JUAN CARLOS; PAULO, JOSÉ DAVID

    2007-01-01

    Objetivos: determinar la variación de la agudeza visual cercana en pacientes expuestos a campos magnéticos intensos por períodos cortos en estudios de resonancia magnética. Métodos: estudio descriptivo de una serie de casos, que incluyó 9 hombres y 31 mujeres alfabetas mayores de 40 años; debían tener una agudeza visual mejor de 20/200 y no estar bajo los efectos de medicamentos ansiolíticos. Estas personas fueron sometidas a procedimientos diagnósticos de resonancia magnética de cabeza y cue...

  8. Redes en estado de reposo: revisión y aplicaciones de un concepto en evolución

    OpenAIRE

    Arrubla, Jorge

    2016-01-01

    RESUMEN El concepto de redes en estado de reposo se refiere a fluctuaciones coherentes de la actividad cerebral, presentes en forma de redes que aparecen cuando los sujetos no están ocupados en alguna actividad o proceso cognitivo superior. Estas redes han sido identificadas en estudios de resonancia magnética funcional y reflejan un alto nivel de conectividad del cerebro humano. El concepto ha crecido en notoriedad hasta tal punto que ahora es casi rutina entre los grupos que usan resonancia...

  9. Synthesis and characterization of magnetic nanoparticles of oxides for dual MnFe{sub 2}O{sub 4} bioseparation, stabilized in fatty acid and the system chitosan - Eu(TTA){sub 3}(TPPO){sub 2}. Studies on the influence of doping with Gd{sup 3+}, Tb{sup 3+}, Ho{sup 3+} e Eu{sup 3+} in structural and magnetic properties; Sintese e caracterizacao de nanoparticulas magneticas de oxidos duplos de MnFe{sub 2}O{sub 4} para biosseparacao, estabilizadas em acido graxo e recobertas pelo sistema quitosana - Eu(TTA){sub 3}(TPPO){sub 2}. Estudo da influencia da dopagem com Gd{sup 3+}, Tb{sup 3+}, Ho{sup 3+} e Eu{sup 3+} nas propriedades estruturais e magneticas

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, Thelma Antunes Rodrigues

    2014-07-01

    This work was synthesized and characterized ferrite magnetic nanoparticles manganese, using the chemical coprecipitation method. By varying the heating time under 98°C (0, 10,20,40,60 3 80 minutes), the molar percentage of doping (1, 3, 5, 7, and 10%), gadolinium, europium, terbium and holmium. Magnetic ferrite nanoparticles and manganese ferrite doped with manganese were synthesized by coprecipitation method starting with chloride solutions of metals (iron (III), manganese (II), europium (III), gadolinium (III), terbium (III) and holmium (III)) and NaOH 5mol.L{sup -1} as precipitating agent. The magnetic nanoparticles were characterized by scanning electron microscopy, infrared spectroscopy, X-ray diffraction, magnetization curves, and thermal analysis. Most of manganese ferrite particles showed superparamagnetic behavior. After the characterization it was found that the samples synthesized manganese ferrite with more than 40 minutes heating time, crystal structure showed the characteristic pattern of the inverted manganese ferrite spinel type. The stabilization of the samples in oleic acid nanoparticles produced with a hydrophobic outer layer and facilitated by coating chitosan biopolymer, since this has a positive charge. Among the doped samples there was no significant change in the magnetic behavior. Several techniques for characterizing these materials have been used such as X-ray diffraction spectrum in the infrared region, magnetization curves and thermal analysis. The resins were tested as magnetic material for the separation of biological materials. In this paper, are used as biological targets separation of bovine serum albumin. (author)

  10. Characterization of magnetic nano particles of CoFe{sub 2}O{sub 4} and CoZnFe{sub 2}O{sub 4} prepared by the chemical co-precipitation method; Caracterizacion de nanoparticulas magneticas de CoFe{sub 2}O{sub 4} y CoZnFe{sub 2}O{sub 4} preparadas por el metodo de coprecipitacion quimica

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, J.; Zambrano, G.; Gomez, M. E. [Universidad del Valle, Departamento de Fisica, Laboratorio de Peliculas Delgadas, Ciudad Universitaria Melendez, 25360 Cali (Colombia); Prieto, P. [Universidad del Valle, Centro de Excelencia en Nuevos Materiales, Ciudad Universitaria Melendez, 25360 Cali (Colombia); Espinoza B, F. J., E-mail: javierlo21@gmail.com [IPN, Centro de Investigacion y de Estudios Avanzados, Unidad Queretaro, Libramiento Norponiente No. 2000, Fracc. Real de Juriquilla, 76230 Queretaro (Mexico)

    2012-07-01

    Magnetic cobalt ferrite nanoparticles of CoFe{sub 2}O{sub 4} and CoZnFe{sub 2}O{sub 4} were prepared by co-precipitation technique from aqueous salt solutions of Co (II), ZnSO{sub 4} and Fe (III), in an alkaline medium. CoFe{sub 2}O{sub 4} powder samples were structurally characterized by X-ray diffraction, showing the presence of the most intense peat at 2{theta} = 413928{sup o} (Co K{alpha}1) corresponding to the (311) crystallographic orientation of the CoFe{sub 2}O{sub 4} spinel phase. The mean size of the crystalline of CoFe{sub 2}O{sub 4} and CoZnFe{sub 2}O{sub 4} nanoparticles determined from the full width at half maximum of the strongest reflection of the (311) peak by using the Scherrer approximation was calculated to be 11.4 and 7.0 ({+-} o.2) nm, respectively. Transmission electron microscopy studies permitted determining nanoparticle size of CoZnFe{sub 2}O{sub 4}. Fourier transform infrared spectroscopy was used to confirm the formation of Fe-O bonds, allowing identifying the presence of ferrite spinel structure. Magnetic properties were investigated with the aid of a vibrating sample magnetometer at room temperature Herein, the sample showed superparamagnetic behavior, determined by the hysteresis loop finally, due to the hysteresis loop of the CoZnFe{sub 2}O{sub 4} is very small, our magnetic nanoparticles can be considered as a soft magnetic material. These magnetic nanoparticles have interesting technological applications in biomedicine given their biocompatibility, in nano technology, and in ferro fluid preparation. (Author)

  11. Study of the effect of dilution on the microstructural and magnetic properties of Mn{sub 0.65}Zn{sub 0.35}Fe{sub 2}O{sub 4} ferrites by combustion reaction; Estudo do efeito da diluicao nas propriedades microestruturais e magneticas de ferritas Mn{sub 0.65}Zn{sub 0.35}Fe{sub 2}O{sub 4} por reacao de combustao

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R.L.P.; Costa, A.C.F.M., E-mail: raffitasantos8@hotmail.com [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia de Materiais; Diniz, V.C.S., E-mail: veronicacristhina@hotmail.com, E-mail: c_r_i_s_2005@yahoo.com.br [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Dept. de Engenharia de Materiais; Kiminami, R.H.G.A., E-mail: ruth@ufscar.br [Universidade de Sao Carlos (UFSCar), Sao Carlos, SP (Brazil). Dept. de Engenharia de Materiais; Cornejo, D.R., E-mail: cornejo@if.usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Fisica

    2016-10-15

    The Mn-Zn ferrites have been used in various technological areas, due to their attractive properties in technical and scientific senses. This paper aimed to synthesize Mn{sub 0.65}Zn{sub 0.35}Fe{sub 2}O{sub 4} ferrites by combustion reaction and evaluate the effect of dilution of the reactants in distilled water on the microstructural and magnetic characteristics. The samples were characterized by X-ray diffraction, scanning and transmission electron microscopy, Curie temperature and magnetic measurements. It was observed that increasing dilution with water during synthesis by combustion reaction was favorable for obtaining monophasic Mn{sub 0.65}Zn{sub 0.35}Fe{sub 2}O{sub 4} ferrite. It also favored a decrease in the agglomerate size and an increase in Curie temperature with maximum value of saturation magnetization of 62 emu/g for the sample diluted in 1:10 ratio. (author)

  12. Influence of Zn{sup 2+} content on morphological and magnetic properties of Mn{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4} ferrites synthesized on a large scale by combustion reaction; Influencia do teor de Zn{sup 2+} nas caracteristicas morfologicas e magneticas de ferritas Mn{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4} sintetizados em grande escala por reacao de combustao

    Energy Technology Data Exchange (ETDEWEB)

    Diniz, V.C.S.; Silveira Junior, J.E.R.; Costa, A.C.F.M., E-mail: veronicacristhina@hotmail.com, E-mail: juniorramos_1@hotmail.com, E-mail: c_r_i_s_2005@yahoo.com.br [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Departamento de Engenharia de Materiais; Cornejo, D.R., E-mail: cornejo@if.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica; Kiminami, R.H.G.A., E-mail: ruth@ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia de Materiais

    2017-04-15

    This study aimed to evaluate the influence of Zn{sup 2+} in the morphological and magnetic characteristics of ferrites Mn{sub 1-x}Zn{sub x} Fe{sub 2} O{sub 4} (where x= 0.0, 0.35, 0.5 and 0.65 mol of Zn) synthesized by combustion reaction in a pilot scale with batches of 200 g/reaction. The samples were characterized by X-ray diffraction, scanning/transmission electron microscopy, and magnetic measurements. The results indicated that all compositions were single phase of ferrite; morphologically the addition of Zn to MnFe{sub 2} O{sub 4} system caused a slight reduction in size of the agglomerates, and reduced the particle size, but this behavior was not linear with the Zn{sup 2+} content. The samples had characteristic magnetic behavior of soft magnetic materials, maximum saturation magnetization of 62 emu/g for the sample with lower zinc content in its composition. (author)

  13. Anisotropy of the Chemical Shift Tensor for Fluorines in UF{sub 6} : Application to the Fluorine Atom Movement Model; Anisotropie du Tenseur de Deplacement Chimique des Fluors dans UF{sub 6}: Application au Modele du Mouvement des Atomes de Fluor; Anizotropiya tenzora khimicheskogo zameshcheniya ftora v UF{sub 6}. Primenenie k modeli dvizheniya atomov ftora; Anisotropia del Tensor de Desplazamiento Quimico de los Atomos de Fluor en el UF{sub 6}: Aplicacion al Modelo del Movimiento de los Atomos de Fluor

    Energy Technology Data Exchange (ETDEWEB)

    Rigny, P. [Centre d' Etudes Nucleaires de Saclay (France)

    1965-10-15

    efectuado un primer estudio del hexafluoruro de uranio policristalino midiendo la resonancia magnetica del fluor a 40 Mc/s. Se recuerda en la memoria que el espectro obtenido a baja temperatura (t < -20 Degree-Sign C) puede descomponerse en 2 lineas superpuestas, lo que confirma la estructura hallada por Hoard y Stroupe con rayos X, segun la cual, y dado que el octaedro UF{sub 6} tiene un eje largo y dos ejes cortos, los atomos de fluor se distribuyen en dos tipos de posicion. La modificacion del espectro con la temperatura -coalescencia de las dos lfneas- sugiere un desplazamiento de los atomos de fluor entre esas posiciones. Al repetir estos experimentos a 56,4 Mc/s y a 94 Mc/s, el autor ha podido comprobar la existencia de una marcada anisotropfa axial del tensor de desplazamiento qufmico (alrededor de 1000 partes por millon). La lfnea de absorcion observada en estas condiciones para muestras en polvo es compleja y para estudiarla es necesario recurrir a una funcion de forma f(h), representativa de la probabilidad que posee cada grano de polvo de tener una orientacion que produzca resonancia para el valor h del campo. En ausencia de movimiento (espectro de baja temperatura) la funcion de forma para cada una de las dos lfneas (correspondientes a los dos tipos de posicion) presenta la forma obtenida para un conjunto de atomos equivalentes. Se sabe que los parametros de los tensores de desplazamiento qufmico dan informacion sobre la indole de los enlaces qufmicos. Se llega asf, por ejemplo, a atribuir un pronunciado caracter ionico (I Asymptotically-Equal-To 1/2) a los enlaces del uranio con los dos atomos de fluor mas alejados. Cuando se produce movimiento, la funcion de forma es muy distinta y depende del tipo de movimiento. Para el UF{sub 6}, el estudio de la forma de la lfnea espectral unica (t > 20 Degree-Sign C), cuando existe anisotropfa pone de manifiesto que los atomos de fluor de una misma molecula se intercambian entre sf y que a 30 Degree-Sign C cada atomo

  14. Shallow landslide prediction and analysis with risk assessment using a spatial model in the coastal region in the state of São Paulo, Brazil

    Science.gov (United States)

    Camarinha, P. I. M.; Canavesi, V.; Alvalá, R. C. S.

    2013-10-01

    In Brazil, most of the disasters involving landslide occur in coastal regions, with population density concentrated on steep slopes. Thus, different approaches have been used to evaluate the landslide risk, although the greatest difficulty is related to the scarcity of spatial data with good quality. In this context, four cities located on the southeast coast of Brazil - Santos, Cubatão, Caraguatatuba and Ubatuba - in a region with the rough reliefs of the Serra do Mar and with a history of natural disasters were evaluated. Spatial prediction by fuzzy gamma technique was used for the landslide susceptibility mapping, considering environmental variables from data and software in the public domain. To validate the susceptibility mapping results, it was overlapped with risk sectors provided by the Geological Survey of Brazil (CPRM). A positive correlation was observed between the classes most susceptible and the location of these sectors. The results were also analyzed from the categorization of risk levels provided by CPRM. To compare the approach with other studies using landslide-scar maps, correlated indexes were evaluated, which also showed satisfactory results, thus indicating that the methodology presented is appropriate for risk assessment in urban areas and can be replicated to municipalities that do not have risk areas mapped.

  15. TUMORES CEREBRALES ASOCIADOS A EPILEPSIA

    Directory of Open Access Journals (Sweden)

    Dr. Manuel G. Campos

    2017-05-01

    La Resonancia Magnética de cerebro es mandatoria en el estudio de todo paciente con epilepsia, para detectar lesiones estructurales, especialmente en epilepsia focal. Alrededor del 30% de los pacientes operados de epilepsia refractaria presentan tumores. En estos casos el control de crisis post-operatorio llega hasta un 70% en el seguimiento a largo plazo.

  16. Getting an MRI (For Kids)

    Medline Plus

    Full Text Available ... A) Staying Safe Videos for Educators Search English Español Getting an MRI (Video) KidsHealth / For Kids / Getting an MRI (Video) Print en español Obtención de una resonancia magnética, RM (video) An ...

  17. Geophysical contribution for Folha Patos (PI, Brazil)

    International Nuclear Information System (INIS)

    Rodrigues, J.C.; Mota, A.C.; Metelo, M.J.; Vasconcelos, R.M. de

    1990-01-01

    As a part of PLGB (Brazilian Geologic reconnaissance program), executed in 1986-1989 period by Companhia de Pesquisa de Recursos Minerais - CPRM to the Departamento Nacional da Producao Mineral - DNPM, geophysical studies were carried out in the Patos Quadrangle (SB. 24-Y-C-V). Gravimetric, magnetometric and scintillometric methods were performed over selected profiles, and the interpretation of aerial gamma-spectrometric maps (total, potassium, uranium and thorium channels) were integrated with geologic data. Computer programs Magpoly and Gravpoly were utilized in modelling geophysical surface data. Results of theses studies were auxiliary to the geological mapping of that area, specially in localizing lithological contacts and differentiations, tectonic structures, and revealed the structural compartimentation among crustal segments with distinct metamorphic grades. (author)

  18. Clinical utility of MR imaging in chronic progressive radiation myelopathy

    International Nuclear Information System (INIS)

    Melki, P.S.; Halimi, P.; Wibault, P.; Doyon, D.

    1990-01-01

    This paper defines the diagnostic and prognostic value of MR imaging in chronic progressive radiation myelopathy 9CPRM). In this series, MR imaging showed excellent sensitivity (199%) for the demonstration of radiation-induced lesions of the spinal cord. Fifty percent of the cases showed spinal cord hypertrophy (pseudotumoral, 33%; cystic, 17%) occurring within 8 months of the clinical onset of myelopathy. The remaining 50% showed spinal cord atrophy, which occurred more than 8 months following the onset of myelopathy. These medullary lesions were located at least partially in the radiation field but extended beyond its boundaries in 73% of the cases. MR imaging helped to establish disease prognosis: spinal cord hypertrophy was usually associated with neurologic deterioration and fatal outcome within a mean of 11.5 months; in spinal atrophy, neurologic deficit was often static and survival rates were better

  19. MAPRAD: mapping of radioactivity in Brazilian soils

    International Nuclear Information System (INIS)

    Ribeiro, Fernando C.A.; Signorelli, Carla de A.; Conti, Claudio de C.; Lauria, Dejanira da C.; Ferreira, Ingryd M.; Carvalho, Laercio L. de; Rio, Monica A. Pires do; Trindade Filho, Octavio Luiz; Gonzalez, Sergio de A.; Silva, Tadeu Augusto de A.; Sousa, Wanderson de O.; Cunha, Fernanda G. da

    2011-01-01

    The MAPRAD Project main objective is to increase the knowledge of the distribution of natural radioactivity in soils of Brazilian national territory and to provide (among others) information which are essential for medical geology and environmental radiation safety researches and for decision-making process regarding soil contamination levels. It also aims to make available the generated information for researchers and for public, through an online database. Soil samples are collected by the Geological Survey of Brazil (CPRM) and are sent to the Institute of Radioprotection and Dosimetry (IRD), National Commission of Nuclear Energy (CNEN), where they are processed and analyzed for determination of concentrations of radionuclides by gamma spectrometry. The results are inserted into a database containing the sample information as geographic coordinates of the samples and land use. After the sample analysis, results are made available for the scientific community access on Internet. (author)

  20. Papel da ranitidina como meio de aprimorar a qualidade do exame de colangiopancreatografia por ressonância magnética The role of ranitidine in the enhancement of imaging quality in magnetic resonance cholangiopancreatography

    Directory of Open Access Journals (Sweden)

    Lucas Rios Torres

    2013-04-01

    Full Text Available OBJETIVO: Avaliar o impacto da ranitidina por via oral na qualidade do exame de colangiopancreatografia por ressonância magnética (CPRM. MATERIAIS E MÉTODOS: Trinta e dois pacientes realizaram CPRM com aquisições 3D e 2D, com três estratégias de supressão do sinal líquido gastrintestinal: a apenas em jejum; b 12 horas após ingerir 300 mg de ranitidina; c após a ingestão de solução de gadolínio. Três observadores avaliaram os estudos, atentos para o grau de visualização da árvore biliopancreática. Foi medida a concordância interobservador com o teste kappa. A diferença entre técnicas e formas de aquisição foi avaliada pela média da soma dos escores de graduação. RESULTADOS: As três estratégias de supressão do sinal líquido gastrintestinal apresentaram elevada reprodutibilidade. A supressão do sinal líquido gastrintestinal com a ranitidina foi semelhante ao jejum e ambas foram piores do que a solução de gadolínio. As aquisições 3D superaram a 2D apenas na visualização do ducto cístico e da vesícula biliar, sendo inferior ou equivalente nos demais segmentos ductais biliopancreáticos. CONCLUSÃO: O uso da ranitidina não parece justificado para aprimorar a avaliação da árvore biliopancreática em exames de CPRM. A CPRM 2D apenas em jejum permite a visualização ductal com elevada qualidade e reprodutibilidade na maioria dos casos.OBJECTIVE: To assess the impact of oral ranitidine on the imaging quality in magnetic resonance cholangiopancreatography (MRCP. MATERIALS AND METHODS: Thirty-two patients underwent MRCP with 3D and 2D acquisitions, and three strategies for suppression of the gastrointestinal fluid signal: a only at fasting; b 12 hours after ingestion of 300 mg ranitidine; c after oral administration of gadolinium solution. Three observers reviewed the images with a focus on the degree of visualization of the biliopancreatic tree. The interobserver agreement was evaluated with the kappa test

  1. Geophysical contribution for the study of the Granitic Batholit Santa Helena, southwest of the Amazonian Craton; Contribuicao geofisica ao estudo do Batolito Granitico Santa Helena, sudoeste do Craton Amazonico

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Vanessa Biondo; Mantovani, Marta Silvia Maria, E-mail: van.biondo@gmail.com, E-mail: msmmanto@usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Astronomia, Geofisica e Ciencias Atmosfericas

    2012-08-15

    The Santa Helena batholith is subject of many controversies concerning its geographical extension, lithological constitution, geochemical characterization and geotectonic setting. This paper aims to contribute for a better understanding of this intrusion using geophysical data (gammaspectrometric and aeromagnetic). These data were obtained through surveys contracted by the Geological Survey of Brazil (CPRM) flown over the study region. Given the compositional variety of the rocks, we analyzed the susceptibility contrast (magnetometry) and distribution of radioelements (K, Th and U, measured by gammaspectrometry) in the batholith. The resulting geophysical signature is different when comparing the northern and southern parts of the body, suggesting the presence of two distinct suites. The boundary between these two suites coincides with the location of an approximately N75 deg W oriented fault system that extends through the batholith. (author)

  2. Petrographic characterization and preliminary lithogeochemistry of albitites from Folha Bramado, northwest of Bahia state, Brazil

    International Nuclear Information System (INIS)

    Burgos, Cristina Maria; Pinho, Ivana Conceicao de Araujo; Martins, Adriano Alberto Marques; Teixeira, Leo Rodrigues; Oliveira, Rita Cunha Leal Menezes de; Cruz Filho, Basilio Elesbao da; Wosniak, Ricardo

    2011-01-01

    The mapping geological works carried out by CPRM, in the scope of the Brumado-Condeuba Project, had proceeded to the sampling from granitoids in the 'Folha Brumado'. The majority of the samples were classified as biotite gneiss and two of them recognized as albitites. Lithogeochemical data had proved that the rocks are alkaline, metaluminous, potash-rich (except for the two classified as albitites that are soda-rich), enriched in rare earth elements, with negative anomaly in europium and typical standards of A-type granitoids. They had been located in the field of the within-plate granites in the discrimination diagrams for the tectonic interpretation. The albitites of the 'Folha Brumado' are similar to the albitites that had been described in the Uranium Province of Lagoa Real. (author)

  3. Geological and geophysical characterization of the Rio das Velhas greenstone belt

    International Nuclear Information System (INIS)

    Araujo Vieira, Marcelo de; Silva, Sergio Lima da

    1995-01-01

    In order to obtain larger information about the high potentiality of the Greenstone belt Rio das Velhas, it has been, nowadays, the object of various geological research works, among then, the Detailed Geophysical Airborne Survey of the Rio das Velhas Project (DNPM/Mining Companies Partnership) and the Geological Mapping in the scale of 1:25.000 (DNPM/CPRM). Such initiatives have brought, by themselves, valuable contributions for better knowledge of the region. In this context, this study shows a proposal of integration of geological and geophysical data, as much quantitative as qualitative, with the aim at the maximum advantage of the obtained data for the next prospecting and geological mapping works. (author). 6 refs., 2 figs., 1 tab

  4. Genetic signatures coupled with lineage shift characterise endemic evolution of Dengue virus serotype 2 during 2015 outbreak in Delhi, India.

    Science.gov (United States)

    Choudhary, Manish Chandra; Gupta, Ekta; Sharma, Shvetank; Hasnain, Nadeem; Agarwala, Pragya

    2017-07-01

    In 2015, New Delhi witnessed a massive outbreak of Dengue virus (DENV) resulting in high morbidity and mortality. We report the molecular characterisation of the dominant circulating DENV strain to understand its evolution and dispersal. DENV infections were diagnosed by detection of IgM/NS1 antigen, and serotyping was performed by C-PrM PCR. Envelope gene was amplified, and variation(s) in envelope gene were analysed. Phylogenetic tree construction, time-based phylogeny and origin of DENV were analysed. Site-specific selection pressure of envelope gene variants was analysed. Confirmed DENV infection was observed in 11.34% (32 of 282) cases, while PCR positivity for C-PrM region was observed in 54.16% (13 of 24) of NS1 antigen-positive cases. All samples belonged to serotype 2 and cosmopolitan genotype. Phylogenetic analysis using envelope gene revealed segregation of cosmopolitan genotype strains into specific lineages. The Indian strains clustered separately forming a distinct monophyletic lineage (lineage III) with a signature amino acid substitution viz., I162V and R288K. Selection pressure analysis revealed that 215D, 288R and 304K were positively selected sites. The rate of nucleotide substitution was 6.93 × 10 -4 substitutions site-1 year-1 with time to most common ancestor was around 10 years with JX475906 (Hyderabad strain) and JN030345 (Singapore strain) as its most probable ancestor. We observed evolution of a distinct lineage of DENV-2 strains on the Indian subcontinent with possible changes in endemic circulating dengue strains that might give rise to more pathogenic strains. © 2017 John Wiley & Sons Ltd.

  5. New Methods and Facilities for the Measurement of Physical Properties of Reactor Components and Irradiated Materials; Nouveaux Procedes et Instruments de Mesure des Proprietes Physiques des Elements de Reacteur et des Matieres Irradiees; Novye metody i sredstva izmereniya fizicheskikh s vojstv komponentov reaktora i obluchennykh materialov; Nuevos Metodos y Equipos para Medir Propiedades Fisicas de Componentes de Reactor y de Materiales Irradiados

    Energy Technology Data Exchange (ETDEWEB)

    Foerster, F.; Mueller, P. [Institut Dr. Foerster, Reutlingen, Federal Republic of Germany (Germany)

    1965-09-15

    zone 'chaude ' du reacteur. Ils discutent la relation entre la conductivite electrique et la dose d'irradiation. Les auteurs decrivent un instrument de mesure de la permeabilite, de la remanence et de la force co- ercitive en fonction des contraintes mecaniques, de la deformation elastique et inelastique et de la dose d'irradiation. Ils donnent des mesures de la variation des proprietes magnetiques en fonction des contraintes elastiques et de la deformation inelastique. Ils etudient les effets de l'irradiation sur la permeabilite et sur la force coercitive. Les auteurs decrivent un instrument permettant la mesure rapide et la lecture directe de la permeabilite des elements en acier inoxydable. Ils expliquent la correlation entre la permeabilite et la teneur en ferrite {Delta}. Us discutent certaines mesures du pourcentage de ferrite {Delta} dans les soudures de tubes en acier inoxydable ainsi que certaines mesures de precipitation de ferrite {Delta} en fonction de la deformation inelastique (forgeage a la main d'elements combustibles pour reacteurs). (author) [Spanish] Se describe un intrumento para medir y registrar en forma totalmente automatica el modulo de Young, el modulodecorte y la capacidad de amortiguamiento, en funcion de la temperatura y el tiempo. El modulo de Young se determina excitando muestras de diversos tamanos con sus frecuencias naturales, mientras que la capacidad de amortiguamiento se mide en funcion de la libre atenuacion de la vibracion, o bien por la anchura media de la curva de resonancia. Se presentan ejemplos de medidas de la recuperacion despues de provocar danos por irradiaciones y deformaciones plasticas asf como grado de grafitacion. Se describe la deteccion de fallas y variaciones de densidad en barras de grafito. Se explica, ademas, un metodo para investigar la retencion de pastillas de UO{sub 2} en tubos austenfticos de pared delgada. Se describe un horno especial para estudiar el comportamiento elastico e inelastico de muestras

  6. Molecular Dynamics Investigated by Neutron Scattering; Etude de la Dynamique Moleculaire au Moyen de la Diffusion des Neutrons; 0418 0421 0421 041b 0415 0414 041e 0412 0410 041d 0418 0415 041c 041e 041b 0415 041a 0423 041b 042f 0420 041d 041e 0419 0414 0418 041d 0410 041c 0418 041a 0418 0421 041f 041e 041c 041e 0429 042c 042e 0420 0410 0421 0421 0415 042f 041d 0418 042f 041d 0415 0419 0422 0420 041e 041d 041e 0412 ; Estudio de la Dinamica Molecular por Dispersion Neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Janik, J. A. [Institute for Nuclear Physics, Cracow (Poland)

    1965-06-15

    }OClO{sub 4} sobre la base de experimentos de dispersion inelastica de neutrones. Los resultados obtenidos indican que la rotacion del grupo NH4 en el perclorato amonico es libre, incluso a temperaturas tan bajas como la del nitrogeno liquido. En lo que respecta al H{sub 3}OClO{sub 4}, se ha observado una vibracion torsional del grupo H{sub 3}O con una frecuencia de 497 cm{sup -1}. Por tanto, a pesar de la identidad de las redes cristalinas del NH{sub 4}CIO{sub 4} y del H{sub 3}OCIO{sub 4}, la dinamica de los grupos NH{sub 4} es diferente de la de los grupos H{sub 3}O. Los resultados se comparan con los obtenidos por espectroscopia Raman y resonancia magnetica nuclear. Por ultimo, se estudia una serie de sustancias desde el punto de vista de su dinamica molecular. (author) [Russian] Kratko rassmatrivaetsja polozhenie s voprosom o primenimosti teorii Krigera- Nel'kina i teorii Griffinga v otnoshenii gazov. Zatem na osnovanii jeksperimentov s zhidkim metanom kriticheski rassmatrivaetsja vopros o primenimosti koncepcii tenzora massy v otnoshenii molekul v kondensirovannom sostojanii. Ubeditel'nymi dovodami protiv primenenija teorii Krigera-Nel'kina v otnoshenii kondensirovannyh sostojanij javljajutsja: sdvig raspredelenija jenergii nejtronov posle rassejanija v storonu bolee vysokih jenergij i otsutstvie zavisimosti neuprugoj chasti ot ugla rassejanija. Sledujushhie razdely posvjashheny rotacionnoj dinamike ammonievyh grupp v soedinenijah ammonija. Bol'shaja chast' jeksperimental'nogo materiala rassmatrivaetsja v svjazi s galoidami ammonija, ishodja iz rezul'tatov jeksperimentov razlichnyh avtorov. Dlja nekotoryh veshhestv svoboda vrashhenija grupp NH{sub 4} poluchena na osnovanii izmerenija nejtronov, togda kak dlja nekotoryh drugih jeto vrashhenie perehodit v krutil'noe kolebanie. V jetom sluchae chastoty krutil'nyh kolebanij, poluchennye razlichnymi avtorami v rezul'tate izmerenija nejtronov, sravnivalis' s chastotami, poluchennymi s pomoshh'ju infrakrasnoj

  7. Oftalmoplejía internuclear bilateral reversible de etiología isquémica. Reporte de un caso

    Directory of Open Access Journals (Sweden)

    Luis Othón Gittins Núñez

    2017-03-01

    Conclusiones: La oftalmoplejía internuclear de etiología isquémica debe ser considerada en el diagnóstico diferencial cuando nos encontramos frente a pacientes con factores de riesgo cardiovascular como obesidad, sedentarismo, dislipidemia, hipertensión, tabaquismo. La resonancia magnética es el método ideal de correlacionar la clínica con la lesión anatómica.

  8. Aplicación de técnicas avanzadas de neuroimágenes en rehabilitación motora

    Directory of Open Access Journals (Sweden)

    John Fredy Ochoa

    2014-09-01

    Conclusión. La versatilidad que ofrece la resonancia magnética permite conocer el estado funcional y estructural del cerebro, generando así nuevas posibilidades de diagnóstico y pronóstico en pacientes que reciben rehabilitación neurológica, con lo que se pueden cuantificar y develar ciertos procesos dinámicos de plasticidad neuronal posteriores a una lesión, que son propios del sistema nervioso central.

  9. Tema 2. Oscilaciones y ondas (Curso 2010-2011)

    OpenAIRE

    Caballero Caballero, María Teresa; Espinosa Tomás, Julián; Pérez Rodríguez, Jorge; Miret Marí, Juan José

    2010-01-01

    1. Oscilaciones: movimiento armónico simple. Oscilaciones amortiguadas y forzadas. Resonancia; 2. Ondas armónicas: función y ecuación de ondas; 3. Sonido: ondas sonoras, velocidad de propagación; 4. Intensidad de las ondas. Fenómenos de propagación: reflexión, refracción y difracción; 5. Interferencias. Ondas estacionarias.

  10. Reconstrucción 3D usando superficies trianguladas dados contornos paralelos

    Directory of Open Access Journals (Sweden)

    Manuel Guillermo Forero

    2001-07-01

    Full Text Available El presente artículo muestra una técnica de triangulación empleada para la reconstrucción de superficies tridimensionales (3D a partir de contornos paralelos. Esta técnica es usada para el modelamiento de la cabeza y el cerebro a partir de imágenes de resonancia magnética (IRM.

  11. Origen anómalo de la arteria coronaria izquierda en la arteria coronaria derecha y curso ínter-arterial

    Directory of Open Access Journals (Sweden)

    Nilson López, MD

    2010-11-01

    Full Text Available El origen del tronco coronario principal izquierdo a partir de la arteria coronaria derecha o del seno de Valsava opuesto, es una anomalía extremadamente rara con un riesgo potencial de mortalidad. En este informe se describe el caso de una paciente con esta anomalía, inicialmente detectada por coronariografía y posteriormente confirmada mediante resonancia magnética cardiaca.

  12. Correlación clínica y neuro-radiólogica en la eclampsia Clinical and neuroradiographic correlates in eclampsia

    Directory of Open Access Journals (Sweden)

    Eduardo Malvino

    2004-12-01

    Full Text Available Se estudiaron cinco pacientes con eclampsia mediante tomografía computarizada, resonancia magnética nuclear y angio-resonancia. Tres de ellas cursaron con síndrome HELLP. Se apreciaron lesiones bilaterales que involucraron áreas córtico-subcorticales dependientes de ambos territorios vasculares, centro oval, talámicas y mesencéfalo-protuberanciales. La angio-resonancia descartó la presencia de imágenes compatibles con vasoespasmo en arterias de mediano calibre. Con excepción de alteraciones visuales coincidentes con el compromiso del lóbulo occipital, otras lesiones descriptas carecieron de expresión clínica.Brain computed tomography, magnetic resonance imaging and magnetic resonance angiography were performed in five eclamptic patients. Three of them had HELLP syndrome. The findings on the imaging studies showed bilateral lesions affecting regions of the brain, such as cortico-subcortical either posterior and anterior circulation territories, white matter, talamic or mesencephalic-protuberancial areas. No vasoespasm in middle size arteries were observed with magnetic resonance angiography. Although visual disturbance and occipital lobe involvement were correlated, no others mentioned lesions had clinical manifestations.

  13. Diffraction in the edge of a half plane in a bianisotropic media; Difraccion en el borde de un semiplano inmerso en un medio quiral bianisotropo

    Energy Technology Data Exchange (ETDEWEB)

    Villaroel, C; Torres, H.; Zamorano, M.; Obligado, A. [Universidad de Tarapaca, Arica (Chile)

    2001-04-01

    The diffraction of a non uniform plane electromagnetic wave by the edge of a electrically perfectly conducting half plane in a bi-anisotropic media is rigorously analyzed. The high-frequency asymptotic expansion reveals the existence of a coupling effect between a transverse magnetic (or transverse electric) incident plane wave and the transverse electric (or transverse magnetic) slope-diffracted field. A numerical verification using the Mathematic software is presented. [Spanish] Se analiza rigurosamente la difraccion, de una onda plana electromagnetica no-uniforme, en el borde (edge) de un semiplano perfectamente conductor inmerso en un medio quiral (bi-anisotropo). La expansion asintotica de la solucion exacta en alta frecuencia, evidencia la existencia de un efecto de acoplamiento, entre la onda plana transversal magnetica incidente (o transversal electrica) y el campo transversal electrico producido por la difraccion-pendiente (o transversal magnetico). Los campos difractados se evaluan numericamente utilizando el software Matematica.

  14. Automação do Acervo Paleontológico da Coleção do Museu de Ciências da Terra / DNPM-RJ e sua disponibilização na Internet

    Directory of Open Access Journals (Sweden)

    Adriana Abade Pereira Moura

    2005-01-01

    Full Text Available A Internet vem servindo à ciência como ferramenta na busca e no acesso de informações, sendo utilizada por pesquisadores do mundo inteiro como meio de aceleração da troca de idéias para melhor desenvolver suas pesquisas e desenvolver a partir daí novos conceitos na ciência. Tendo consciência desta ferramenta a Companhia de Pesquisa de Recursos Minerais (CPRM criou um programa de cadastro de automatização sobre os seus fósseis, a Base de Dados Paleontológicos (Base Paleo, utilizado pelo Museu de Ciências da Terra do DNPM (Departamento Nacional de Produção Mineral, MN-UFRJ (Museu Nacional do Rio de Janeiro e Dep. Geologia da UFRJ (Universidade Federal do Estado do Rio de Janeiro. A entrada de dados é efetuada através de um programa que engloba duas etapas: a primeira, executada pelas instituições conveniadas que trata da geração de movimento para a inclusão de novos registros de fósseis através do ACESS, e a segunda elaborada pela CPRM através do SQL/SERVER para a inclusão e disponibilização dos dados para internet. A Base de Dados Paleontológicos reúne atualmente 20.986 documentos sendo 11.019 documentos do DNPM, 6.088 do Museu Nacional e 3.879 da CPRM, disponíveis pela Internet no site ttn://www.cnrm.gov.br. Dentro do âmbito da Base Paleo criou-se o projeto "Atualização da Coleção dos fósseis existentes no Museu de Ciências da Terra / DNPM" para melhor divulgação do acervo via web. Neste sistema de informação virtual constam dados referentes à identificação dos fósseis como e onde foram encontrados (município e Estado , latitude e longitude, unidades litoestratigráficas, bioestratigráficas e cronoestratigráficas, táxon, coletor, analista, consta o estado de preservação e a descrição com as devidas referências bibliográficas disponíveis sobre o material. O Museu de Ciências da Terra com esta automação possibilitará maior divulgação de seu acervo, permitindo amplo acesso aos

  15. Geodiversity and geoconservation in Brazil

    Science.gov (United States)

    Cardozo Moreira, Jasmine; Muggler, Cristine Carole

    2014-05-01

    Brazil is a large country with a wide diversity of landscapes and geological features and has been an important world producer of mineral resources. Despite this, until the 90's of last century, there has not been much concern and policies about geological heritage and geoconservation. Only at the end of the century the National Geological Service (CPRM) included the physical characterization of areas with geotouristic interest in its mission of generation and diffusion of geological information. In 1997, was created the Brazilian Commission of Geological and Paleobiological Sites (SIGEP, http://sigep.cprm.gov.br), responsible for the assessment, description and publicizing the sites of geological heritage. This is by now the most comprehensive and relevant initiative to protect the national heritage. It is composed by a fully accessible national database composed by 167 certified sites presented as scientific papers. Furthermore, a web-based applicative for the inventory and protection of geological heritage sites is being developed by the National Geological Service. The wider knowledge about geological heritage can be a useful tool for its conservation and this has been an important goal in the creation of protected areas, by means of environmental education and tourism. In Brazil, actions, research and publications about the subject have increased in the last five years, as well as the outreach and responsible use of the geological heritage. Scientific meetings, conferences and courses are growing and spreading around the country. The main scientific meeting has been the Brazilian Symposium of Geological Heritage that in its second edition (2013) had more than 200 papers presented. At that meeting it was also created the Association in Defence of the Geomining Heritage and the Association of Aspiring Geoparks. Brazil has only one geopark in the Unesco's Global Geopark Network, that is the Araripe Geopark, created in 2006. By the moment, propositions are being

  16. Determinación paramétrica de los ejes de rotación de las articulaciones interfalángicas de los dedos

    OpenAIRE

    Jarque Bou, Néstor; Sancho-Bru, Joaquin L.; Vergara Monedero, Margarita; Pérez González, Antonio; Roda Sales, Alba; Mestre Vicent, S.

    2016-01-01

    Comunicación presentada en el XXI Congreso Nacional de Ingeniería Mecánica, celebrado en Elche en Noviembre de 2016. Los ejes de rotación de las articulaciones interfalángicas de los dedos son aproximadamente paralelos a los pliegues de flexión. Sin embargo, los modelos biomecánicos y ergonómicos existentes suelen considerar ejes de rotación paralelos entre sí y perpendiculares a los ejes longitudinales de las falanges. Recientemente se han utilizado técnicas de resonancia magnéti...

  17. La impedancia eléctrica normalizada de transductores cerámicos piezoeléctricos como herramiento de evaluación y caracterización

    OpenAIRE

    San Emeterio, José Luis; Ramos, Antonio; Sanz Sánchez, Pedro Tomás

    1999-01-01

    [ES] El concepto de impedancia eléctrica normalizada proporciona un importante mecanismo de análisis y evaluación de transductores piezoeléctricos en el entorno de una resonancia aislada. En el caso del resonador piezoeléctrico, esta metodología permite: a) aislar el efecto de la geometría (área y espesor) del asociado al tipo de material y b) evaluar cómodamente el efecto separado de distintos tipos de pérdidas intrínsecas. Se presentan patrones normalizados de impedancia correspond...

  18. Síndrome MAPE, heavy eye y esclerodermia

    OpenAIRE

    Brugnoli de Pagano, Ofelia; Pagano, Gabriela

    2009-01-01

    Paciente de 60 años de edad y sexo femenino con esclerodermia y miopía alta bilateral que consulta por estrabismo y ptosis palpebral. El estrabismo consiste en esotropía progresiva con hipotropía de ojo derecho (OD) asociado a miopía alta axial con gran tamaño del globo ocular medido por ecometría ultrasónica que conjuntamente con imágenes de Resonancia Magnética Nuclear (RMN) llevan al diagnóstico de Síndrome MAPE (Miopic Acquired Progressive...

  19. Asociación entre la mutación homocigota c.318A>T en el exón 2 del gen EIF2B5 y la forma infantil de la leucoencefalopatía con sustancia blanca evanescente

    OpenAIRE

    Carmen Esmer; Gabriela Blanco Hernández; Víctor Saavedra Alanís; Jorge Guillermo Reyes Vaca; Antonio Bravo Oro

    2017-01-01

    Introducción: La leucoencefalopatía con sustancia blanca evanescente es una de las leucodistrofias más frecuentes. Generalmente inicia en la infancia y presenta un patrón de herencia autosómica recesiva. El 90% de los casos manifiesta mutaciones en uno de los genes que codifican para las cinco subunidades del factor de iniciación eucariótica 2 (EIF2B5). El diagnóstico se realiza por las manifestaciones clínicas, hallazgos en la resonancia magnética cerebral y estudios moleculares confirmatori...

  20. Advanced Nuclear Magnetic Resonance

    OpenAIRE

    Alonso, Diego A.

    2014-01-01

    Transparencias en inglés de la asignatura "Resonancia Magnética Nuclear Avanzada" (Advanced Nuclear Magnetic Resonance) (36643) que se imparte en el Máster de Química Médica como asignatura optativa de 3 créditos ECTS. En esta asignatura se completa el estudio iniciado en la asignatura de quinto curso de la licenciatura en Química "Determinación estructural" (7448) y en la del Grado de Química de tercer curso "Determinación estructural de los compuestos orgánicos" (26030) en lo referente a té...

  1. El viaje y el arquitecto

    OpenAIRE

    Baladrón, Alfredo

    2014-01-01

    A lo largo de la historia, la formación del arquitecto ha venido acompañada por el viaje. El “grand tour” completaba, inicialmente, los conocimientos de historia y composición, pero servía, a su vez, como una fuente de experiencias que acompañarían al arquitecto a lo largo de su vida y obra. El hecho mismo de viajar supone una deslocalización, una tabula rasa en la que los sentidos se despiertan y agudizan, haciendo del sujeto una caja de resonancia sensible que permite una profunda asimilaci...

  2. Plasmonic nanoengineering in hollow metal nanostructures: an electron energy-loss spectroscopy study

    OpenAIRE

    Genç, Aziz; Universitat Autònoma de Barcelona. Departament de Física

    2015-01-01

    Resumen en Español Las nanoestructuras metálicas están siendo objeto de gran atención dada su capacidad para generar resonancias plasmónicas, que son oscilaciones colectivas de electrones alojados en la banda de conducción en un metal excitado por efecto de un campo electromagnético. El creciente interés entorno a las nanoestructuras metálicas como fuentes de plasmones, ha resultado en el desarrollo de un nuevo campo, la plasmónica, definida como la ciencia y tecnología de la generación, cont...

  3. Estudio de los metabolitos secundarios exudados por las hojas de Aloe barbadensis

    OpenAIRE

    López González, Germán

    2016-01-01

    Debido a las numerosas propiedades terapéuticas Aloe Barbadensis, como cicatrizantes, hidratantes digestivas o anti-inflamatorias; se plantea el estudio, aislamiento y determinación estructural de los componentes de su exudado. Este se obtiene al hacer un corte en la hoja, y contiene principalmente antraquinonas y glicósidos de antronas, algunos de ellos con actividad anti-cancerígena reportada. Se realizará también un estudio biodirigido del mismo y se utilizarán técnicas como la resonancia ...

  4. Aplicación de técnicas avanzadas de neuroimágenes en rehabilitación motora

    OpenAIRE

    John Fredy Ochoa; José Luis Ascencio; Juan Camilo Suárez

    2014-01-01

    Introducción. La resonancia magnética funcional es una técnica no invasiva que permite el mapeo cerebral y la visualización de redes de conectividad. La hemiparesia posterior a un accidente cerebrovascular constituye un buen modelo biológico para estudiar los cambios en la conectividad cerebral. El uso de este modelo se puede expandir si se obtiene información antes y después de la rehabilitación neurológica. Objetivo. Presentar los hallazgos por neuroimágenes funcionales de un paciente co...

  5. Síntesis y análisis estructural de glicomiméticos como potenciales inhibidores enzimáticos

    OpenAIRE

    Témpera, Carlos Agustín

    2013-01-01

    Como objetivo general, se propuso desarrollar Glicomiméticos que puedan ser empleados en el diseño de inhibidores enzimáticos. Como objetivos particulares se propuso: Sintetizar pseudos N-disacáridos unidos mediante un grupo sulfonamido ó metilén bissulfonamido Realizar el análisis estructural de los compuestos obtenidos, empleando principalmente Resonancia Magnética Nuclear Estudiar la actividad biológica de los compuestos sintetizados como Inhibidores Enzimáticos. Facultad de Ciencias Ex...

  6. Léxico e Ideología en el Mortibus Persecutorum de Lactancio: El caso de Valeria y Prisca

    Directory of Open Access Journals (Sweden)

    Felipe GONZÁLEZ VEGA

    2009-11-01

    Full Text Available El texto literario es, al tiemipo que un producto derivado de la estética dominante en su época, generador de un contexto de amplia resonancia en los distintos grupos sociales. Ello se registra como un fenómeno de boomerang, toda vez que la sociedad brinda al escritor la posibilidad en bruto de un acto de creación literaria, para posteriormente, y tras conformarlo de manera artística, hacerlo repercutir sobre sus usuarios.

  7. Palimpsestos con Hélène Cixous: experimentos consigo mismo

    Directory of Open Access Journals (Sweden)

    Alberto Bejarano Hernández

    2017-01-01

    Full Text Available Nuestra reflexión se interesa por la(s lengua(s habitadas por la es - critora y filósofa Héléne Cixous a través de nuestra experiencia en sus clases y en la lectura continua de sus obras de carácter híbrido y abierto. Se trata de un diálogo que desarrollamos con su obra in- cluyendo nuestra propia experiencia con la escritura en forma de palimpsesto en el que tejemos sentidos y sensaciones de la palabra y sus resonancias.

  8. Prototipo para la compensación de armónicos en sistemas trifásicos

    OpenAIRE

    Alzate Gómez, Alfonso; Murillo Yarce, Duberney; Silva Cárdenas, Ricardo León

    2016-01-01

    RESUMEN Contexto: La metodología tradicional para el control de armónicos consiste en el uso de filtros pasivos sintonizados a las componentes armónicas a eliminar. Los filtros pasivos requieren de un diseño exigente en frecuencia para evitar fenómenos de resonancia con otros elementos y no responden a cambios en la dinámica del sistema eléctrico de potencia. Método: Una alternativa de solución de mejores características son los filtros activos de potencia paralelos. Estos filtros a diferenci...

  9. Caracterización clínica y por imágenes de pacientes con el ventrículo izquierdo no compacto

    Directory of Open Access Journals (Sweden)

    Alexander Londoño-Cadavid

    2016-05-01

    Conclusiones: El ventrículo izquierdo no compacto es un diagnóstico cada vez más frecuente en el medio local y su presentación y evolución son similares a series de otros países. La sospecha de la ecocardiografía guarda correlación con los hallazgos en la resonancia magnética. El diagnóstico suele hacerse en infantes y adolescentes en estadios avanzados.

  10. Altitud y riesgo neurológico: alpinistas europeos versus sherpas del Himalaya

    OpenAIRE

    Garrido Marín, Eduardo

    1997-01-01

    La exposición humana a grandes altitudes puede provocar diversos grados de deterioro funcional y orgánico, presentando el sistema nervioso una gran sensibilidad frente a cambios en la presión parcial de oxígeno.Mediante una historia clínica especialmente confeccionada, exploración física neurológica y resonancia magnética (RMI) craneal se estudió a varios grupos de alpinistas de élite que hubieran escalado por encima de los 7.000 m. de altitud en utilizar equipos de oxígeno en una ocasión com...

  11. Propiedad intelectual y plagio en trabajos académicos y profesionales

    OpenAIRE

    Fernando M. Toller

    2011-01-01

    El texto estudia un área poco explorada de la propiedad intelectual. En efecto, el plagio suele estudiarse en relación con la defraudación de la autoría ajena que tiene relevancia comercial y, por tanto, resonancias penales y civiles. El plagio en escritos científicos, exámenes universitarios y monografías estudiantiles, así como el plagio en escritos profesionales de jueces y abogados, han quedado sin embargo desdibujados en los estudios del área. En el artículo se plantea, en primer lugar, ...

  12. Espondilodiscitis cervicales

    OpenAIRE

    Barrecheguren, E.Gª. (E.Gª); Barriga, A. (A.); Barroso, J.L. (J.L.); Villas, C. (C.)

    2001-01-01

    Se revisaron nueve casos de discitis infecciosas de localización cervical de una serie de ochenta pacientes con espondilodiscitis (10%). Se valoraron mediante historia clínica, analítica y radiología simple todos ellos. Además, seis de ellos se valoraron por Resonancia Magnética, tres por gammagrafía ósea, y un caso por punción-biopsia. Los factores predisponentes eran claros en seis de los pacientes, encontrando entre ellos tres sepsis por Stafilococcus aureus, dos intervenciones quirúrgicas...

  13. Oclusión temporal de arterias ilíacas internas en cesárea-histerectomía por placenta acreta: enfoque multidisciplinario

    OpenAIRE

    Hasbun H, Jorge; Palaviccini R, Jaime; Osorio P, Raúl; Cerda SM, Sergio; Castro L, Magdalena; Carreño T, Laura; Valdevenito S, Raúl

    2012-01-01

    Objetivo: Evaluar la eficacia y resultados del tratamiento de la placenta acreta previa central en un caso clínico. Durante el embarazo los métodos diagnósticos por imágenes (ultrasonido y resonancia nuclear magnética) precisaron la localización y penetración de la placenta en la pared uterina. En el período inmediato antes del parto, para disminuir la hemorragia, evitar la hipotensión materna y facilitar el procedimiento quirúrgico, se colocaron balones intraarteriales en ambas ilíacas inter...

  14. Quiste sinovial en articulación interapofisaria lumbar. Una causa infrecuente de lumbociática

    OpenAIRE

    Villas, C. (Carlos); Leyes, M. (Manuel)

    1997-01-01

    Los quistes sinoviales de las articulaciones facetarias pueden ser asintomáticos o provocar dolor lumbar, con o sin clínica radicular. Se considera que son secundarios a traumatismos o a degeneración articular, y ocurren con mayor frecuencia en pacientes con espondi lolistesis. El diagnóstico se establece con la tomografía axial computarizada o la resonancia magnética, que mues tran una lesión quísti ca adyacente a la faceta articu lar. Realizamos una revis...

  15. Desgarros del músculo recto femoral. Actualización en RM

    OpenAIRE

    Mariluis, C.A.; Cupito, J.; Mamone, F.

    2015-01-01

    El desgarro del músculo recto femoral (RF) es el más frecuente dentro del grupo muscular cuadricipital y representa una de las causas más habituales de lesiones musculares del miembro inferior (luego de la injuria del grupo isquiotibial). Dada la complejidad de su anatomía, la sintomatología puede ser poco clara, por lo que los métodos de diagnóstico por imagen y, en especial, la resonancia magnética (RM) aportan información precisa sobre el tipo de desgarro, topografía, extensión y severidad...

  16. Neuroimágenes en las alteraciones del sueño

    Directory of Open Access Journals (Sweden)

    Dr. M. Marcelo Gálvez

    2013-05-01

    Las técnicas de resonancia magnética funcional corresponden a pruebas similares a los test clínicos pero realizados al interior del resonador que permiten una evaluación de las áreas funcionales cerebrales. El PET-CT que utiliza principalmente glucosa radiactiva (18 FDG para visualizar el metabolismo cerebral. Este artículo revisa los principales hallazgos demostrados mediante imágenes estructurales y funcionales en los pacientes con Síndrome de Apnea Obstructiva del Sueño (SAOS, Narcolepsia e Insomnio idiopático.

  17. Extracció de crani en imatges de ressonància magnètica del cervell utilizant una xarxa neuronal convolucional 3D

    OpenAIRE

    Rodriguez Castello, David

    2017-01-01

    Implementation of a 3D convolutional neural network system that gets the information of each voxel from a magnetic resonance image in order to separate the skull from the brain tissue Implementación de un sistema basado en redes convolucionales 3D que extrae la información de los vóxeles de una resonancia magnética del cerebro para poder extraer el cráneo del tejido cerebral. Implementació d'un sistema basat en xarxes neuronals convolucionals 3D que extrau la informació dels vóxels d'un...

  18. SIGNO DE LA "LENGUA BRILLANTE" EN ESCLEROSIS LATERAL AMIOTRÓFICA

    OpenAIRE

    VARGAS OSORIO, JULIANA; NIEBLES POLO, CARLOS

    2015-01-01

    La esclerosis lateral amiotrófica (ELA) es una enfermedad neurodegenerativa. Aunque su diagnóstico sigue siendo clínico, los exámenes adicionales pueden ser utilizados para excluir otras enfermedades, así como para confirmar el diagnóstico. Uno de ellos son las neuroimagenes, donde la más utilizada es la resonancia nuclear magnética (RNM). En la literatura hay pocos signos específicos; el tracto corticoespinal, giro precentral y el cuerpo calloso son los principales sitios de alteración. Un s...

  19. Análisis de señales de medidas mecánicas para el mantenimiento predictivo avanzado

    OpenAIRE

    Montalvo Martín, Cristina

    2012-01-01

    Para contribuir al diseño de un mantenimiento mecánico avanzado, se utilizan en esta tesis las técnicas de análisis de ruido para monitorizar las vibraciones de los internos de un reactor PWR y para vigilar la respuesta dinámica de los sensores de presión capacitivos tipo Rosemount ampliamente utilizados en la industria, sobre todo en las plantas nucleares. Para el primer caso, se han ajustado mediante un método no lineal de Breit- Wigner los espectros de resonancias obtenidos por medio de la...

  20. Análisis de señales de medidas mecánicas para el mantenimiento predictivo avanzado

    OpenAIRE

    Montalvo Martín, Cristina

    2010-01-01

    Para contribuir al diseño de un mantenimiento mecánico avanzado, se utilizan en esta tesis las técnicas de análisis de ruido para monitorizar las vibraciones de los internos de un reactor PWR y para vigilar la respuesta dinámica de los sensores de presión capacitivos tipo Rosemount ampliamente utilizados en la industria, sobre todo en las plantas nucleares. Para el primer caso, se han ajustado mediante un método no lineal de Breit- Wigner los espectros de resonancias obtenidos por medio de la...

  1. La soberanía de las víctimas construcción testimonial de la voz en el marco del moderno estado post-westfaliano

    OpenAIRE

    Ballesteros Pedraza, Leonardo Andrés

    2010-01-01

    La investigación desarrolla un estado del arte del concepto de víctima, la cual posibilita un contrapunteo entre ideas, concepciones y visiones de diferentes miradas que han construido su acervo político, de esta manera el lenguaje es transversal a toda la discusión, la apuesta que se esgrime parte de la experiencia del escucha como testimonio de sentido y de resonancia en la relación víctima-escucha, caracterizada por comunicar lo incomunicable, abstenerse de la violencia y posibilitar la co...

  2. Mixoma ventricular izquierdo

    Directory of Open Access Journals (Sweden)

    Camilo Alvarado-Castro

    2017-05-01

    Conclusión: Las neoplasias cardiacas son infrecuentes siendo el mixoma, el tumor benigno más común del corazón. El diagnóstico puede ser sugerido por los síntomas, aunque es usual encontrar un examen físico normal. Se diagnóstica con el ecocardiograma transtorácico, la tomografía axial computarizada y la resonancia nuclear magnética. El tratamiento es quirúrgico, siendo seguro, efectivo y considerado curativo en la mayoría de las resecciones, con una tasa de supervivencia a 5 años del 83%.

  3. Actualización del síndrome de hombro doloroso: lesiones del manguito rotador

    OpenAIRE

    Ugalde Ovares, Carlos Eduardo; Zúñiga Monge, Daniel; Barrantes Monge, Ricardo

    2013-01-01

    El hombro es una articulación muy móvil, lo cual predispone a múltiples patologías, entre ellas las lesiones del manguito rotador, siendo ésta una causa frecuente de dolor y limitación funcional. Para su valoración se realiza una anamnesis, un examen físico del hombro, múltiples maniobras con diferentes niveles de especificidad y sensibilidad, estudios de imagen como rayos X, ecografía, y resonancia magnética. El conocimiento y tratamiento de las rupturas del manguito rotador está mejorando p...

  4. Validación de una escala de alteración electrofisiológica en pacientes con radiculopatía lumbosacra. Estudio multicéntrico / Validation of electrophysiological abnormalities scale in patient with lumbosacral radiculophaty. Multicentric study

    OpenAIRE

    Forero Díaz, John Jairo

    2010-01-01

    Se realizó el diseño y la validación de una escala de categorización de severidad según hallazgos electrofisiológicos cualitativos en pacientes con radiculopatía lumbosacra, la cual fue aplicada a una muestra de noventa y un pacientes, remitidos para estudio electrofisiológico y que cumplieron la definición de caso; y por consiguiente fueron evaluados clínicamente y con estudios de extensión que incluían resonancia magnética de columna lumbosacra; adicionalmente se aplicaron las escalas de ...

  5. Biofeedback Cardiovascular e suas Aplicações: revisão de literatura

    OpenAIRE

    Gomes, July Silveira; Coghi, Marcos Fábio; Coghi, Priscila

    2014-01-01

    El biofeedback cardiovascular es una técnica de automodulación fisiológica mediada por la resonancia entre dos mecanismos de regulación cardiovascular: el reflejo barorreceptor y la arritmia sinusal respiratoria. Cuando ese fenómeno ocurre, es posible visualizar un aumento significativo en la amplitud de la frecuencia en torno a 0.1Hz, llamada baja frecuencia (low frequency, LF). En ese trabajo, se consultó la base de datos Pubmed y fueron revisados 31 trabajos, publicados entre el 2000 y jun...

  6. Educación, Masonería y Segunda República. Algunos aspectos críticos

    Directory of Open Access Journals (Sweden)

    María Dolores GÓMEZ MOLLEDA

    2010-03-01

    Full Text Available RESUMEN: Clarín lo dijo escuetamente en frase de resonancia gineriana: la educación es la cuestión de España. No es extraño, pues, que abandonar los moldes de nuestra ineducación fuese para la masonería, como para otras minorías españolas interesadas en el tan llevado y traído regeneracionismo hispano, una preocupación básica.

  7. Algunos hitos históricos en el desarrollo del diagnóstico médico por imágenes

    Directory of Open Access Journals (Sweden)

    Dr. M. Marcelo Gálvez

    2013-01-01

    Esta revisión de la historia hace un recorrido cronológico de los hechos y descubrimientos que han hecho posible la aparición y el desarrollo de la radiología. Se enfatizan los desarrollos producidos en los equipos de rayos X, ecografía, tomografía computada, resonancia magnética, radioprotección y de los sistemas de visualización. Veremos además el desarrollo paralelo de los computadores e informática médica debido a su gran influencia en la radiología.

  8. Museo del Holocausto: estudo de uma expografia crítica dos reflexos do regime nazista em Buenos Aires

    Directory of Open Access Journals (Sweden)

    Janaina Cardoso de Mello

    2013-01-01

    Full Text Available The article presents a critical analysis of expography integrating the Holocaust Museum in Buenos Aires, this being divided into three parts: “Eichmann. Él vivió entre nosotros” ; “Imágenes de la Shoá, el Holocausto y sus resonancias en la argentina” and “Identidad: Retratos de testigos de la Shoá”. We discuss categories that comprise museography and historical context, during Nazism period in Germany, which promoted the exodus of Jews and Germans criminals to Argentina between 1933 and 1960.

  9. Green chemistry and nuclear magnetic resonance applications to the valorisation of vegetable oils and l/gnocellulosic biomass residues

    OpenAIRE

    Lucas-Torres Pérez, Covadonga

    2016-01-01

    La alta demanda de materias primas de origen fósil plantea un reto: evitar la pérdida total de recursos del planeta. En este sentido, este trabajo está basado en las novedosas aportaciones de la Química Sostenible en la revalorización de residuos agroalimentarios, estableciéndolos como novedosas materias primas renovables. Así mismo, a lo largo de los capítulos, se han estudiado las aplicaciones que una técnica analítica tan versátil como la Resonancia Magnética Nuclear (RMN), presenta en est...

  10. Incorporación del cine en la transmisión de temas de la física contemporánea

    OpenAIRE

    Attilio, Gabriel

    2016-01-01

    La Física Contemporánea, cuyo nacimiento puede establecerse a finales del siglo XIX, a partir de las experiencias en las que se obtuvieron las primeras evidencias de los fenómenos de radiación y que dieron lugar al descubrimiento del electrón, generó un nuevo marco teórico y práctico para la humanidad en nuestro siglo XXI y permite nuevas tecnologías aplicables en el ámbito de, por ejemplo: • la Medicina (Resonancia magnética nuclear, Tomografía computada, tratamientos a nivel mole...

  11. Properties of self-assembled diluted magnetic semiconductor nanostructures =

    Science.gov (United States)

    Ankiewicz, Amelia Olga Goncalves

    Este trabalho centra-se na investigacao da possibilidade de se conseguir um semicondutor magnetico diluido (SMD) baseado em ZnO. Foi levado a cabo um estudo detalhado das propriedades magneticas e estruturais de estruturas de ZnO, nomeadamente nanofios (NFs), nanocristais (NCs) e filmes finos, dopadas com metais de transicao (MTs). Foram usadas varias tecnicas experimentais para caracterizar estas estruturas, designadamente difraccao de raios-X, microscopia electronica de varrimento, ressonancia magnetica, SQUID, e medidas de transporte. Foram incorporados substitucionalmente nos sitios do Zn ioes de Mn2+ e Co2+ em ambos os NFs e NCs de ZnO. Revelou-se para ambos os ioes dopantes, que a incorporacao e heterogenea, uma vez que parte do sinal de ressonancia paramagnetica electronica (RPE) vem de ioes de MTs em ambientes distorcidos ou enriquecidos com MTs. A partir das intensidades relativas dos espectros de RPE e de modificacoes da superficie, demonstra-se ainda que os NCs exibem uma estrutura core-shell. Os resultados, evidenciam que, com o aumento da concentracao de MTs, a dimensao dos NCs diminui e aumentam as distorcoes da rede. Finalmente, no caso dos NCs dopados com Mn, obteve-se o resultado singular de que a espessura da shell e da ordem de 0.3 nm e de que existe uma acumulacao de Mn na mesma. Com o objectivo de esclarecer o papel dos portadores de carga na medicao das interaccoes ferromagneticas, foram co-dopados filmes de ZnO com Mn e Al ou com Co e Al. Os filmes dopados com Mn, revelaram-se simplesmente paramagneticos, com os ioes de Mn substitucionais nos sitios do Zn. Por outro lado, os filmes dopados com Co exibem ferromagnetismo fraco nao intrinseco, provavelmente devido a decomposicao spinodal. Foram ainda efectuados estudos comparativos com filmes de ligas de Zn1-xFexO. Como era de esperar, detectaram-se segundas fases de espinela e de oxido de ferro nestas ligas; todas as amostras exibiam curvas de histerese a 300 K. Estes resultados suportam a

  12. Existing situation of hydro resources of coal reservoirs in regards to mineral coal mining and processing activities and other human activities; Situacao atual dos recursos hidricos da bacia carbonifera, face as atividades de lavra, beneficiamento e uso do carvao mineral e de outras atividades antropicas

    Energy Technology Data Exchange (ETDEWEB)

    Krebs, Antonio Silvio J [Companhia de Pesquisas de Recursos Minerais (CPRM), Porto Alegre, RS (Brazil); Alexandre, Nadja Zim [Fundacao de Amparo ao Meio Ambiente (FATMA), Florianopolis, SC (Brazil); [Universidade do Extermo Sul Catarinense (UNESC), Criciuma, SC (Brazil)

    1997-12-31

    The coal region which is situated in the south-east of Santa Catarina State (Brazil) is best-known as the Brazilian coal capital. The progress brought to this area by the coal explotation and later by the building of a vast ceramic industrial park has been followed by an intense environmental degradation which presents few favorable conditions for the existence of a good life quality. Nowadays this region has two thirds of its underground and surface water resources degraded by activities related the coal explotation and its use. However during the past twenty-five years some new pollution resources have been settled down in this area, specially those related to the ceramic industry, metal-mechanic, chemical and farming, to name just some of them. Therefore the Companhia de Pesquisa de Recursos Minerais - CPRM, in cooperation with Fundacao do Meio Ambiente - FATMA and Universidade do Extremo Sul Catarinense - UNESC has been carrying out a project named Qualidade das Aguas Superficiais da Bacia Carbonifera. Besides, some aspects related to the underground water resources will be focused in this work for these resources have also been very polluted and by the same pollution causes as those named before. (author) 2 refs., 1 tab.

  13. Brazil Geologic Basic Survey Program - Barbacena - Sheet SF.23-X-C-III -Minas Gerais State

    International Nuclear Information System (INIS)

    Brandalise, L.A.

    1991-01-01

    The present report refers to the Barbacena sheet (SF.23-X-C-III) systematic geological mapping, on the 1:10,000 scale, related to the Levantamentos Geologicos Basicos do Brasil Program - PLGB, carried out by CPRM for the DNPM. Integrated to geochemical and geophysical surveys, the geological mapping not only yielded geophysical and geochemical maps but a consistent to the 1:100.000 scale Metallogenetic/Provisional one as well. The geological mapping carried out during the Project has really evidenced that samples of distinct stratigraphic units had been employed to define the one and only isochrone. However geochronologic Rb/Sr dating performed during the geological mapping phase evidenced Archean ages for rocks of the Sao Bento dos Torres Metamorphic Suite (2684 ± 110 m.y.) and ages of about 2000 m.y. for the Ressaquinha Complex rocks. An analysis of crustal evolution patterns based on geological mapping, gravimetric survey data, aeromagnetometry and available geochronologic data is given in the Chapter 6, Part II, in the test. Major element oxides, trace-elements and rare-earths elements were analysed to establish parameters for the rocks environment elucidation. Geochemical survey was carried out with base on pan concentrated and stream sediments distributed throughout the sheet. (author)

  14. Existing situation of hydro resources of coal reservoirs in regards to mineral coal mining and processing activities and other human activities; Situacao atual dos recursos hidricos da bacia carbonifera, face as atividades de lavra, beneficiamento e uso do carvao mineral e de outras atividades antropicas

    Energy Technology Data Exchange (ETDEWEB)

    Krebs, Antonio Silvio J. [Companhia de Pesquisas de Recursos Minerais (CPRM), Porto Alegre, RS (Brazil); Alexandre, Nadja Zim [Fundacao de Amparo ao Meio Ambiente (FATMA), Florianopolis, SC (Brazil)]|[Universidade do Extermo Sul Catarinense (UNESC), Criciuma, SC (Brazil)

    1996-12-31

    The coal region which is situated in the south-east of Santa Catarina State (Brazil) is best-known as the Brazilian coal capital. The progress brought to this area by the coal explotation and later by the building of a vast ceramic industrial park has been followed by an intense environmental degradation which presents few favorable conditions for the existence of a good life quality. Nowadays this region has two thirds of its underground and surface water resources degraded by activities related the coal explotation and its use. However during the past twenty-five years some new pollution resources have been settled down in this area, specially those related to the ceramic industry, metal-mechanic, chemical and farming, to name just some of them. Therefore the Companhia de Pesquisa de Recursos Minerais - CPRM, in cooperation with Fundacao do Meio Ambiente - FATMA and Universidade do Extremo Sul Catarinense - UNESC has been carrying out a project named Qualidade das Aguas Superficiais da Bacia Carbonifera. Besides, some aspects related to the underground water resources will be focused in this work for these resources have also been very polluted and by the same pollution causes as those named before. (author) 2 refs., 1 tab.

  15. SIMILARIDADE DAS VARIÁVEIS HIDROQUÍMICAS COM O USO DA ANÁLISE MULTIVARIADA, NA BACIA DO SALGADO, CEARÁ

    Directory of Open Access Journals (Sweden)

    EVELINE VIANA SALGADO

    2011-01-01

    Full Text Available This study aimed to identify the similarities among hydrochemical variables describing the groundwater qualities in the Salgado watershed river (Southern Ceará, with the use of multivariate statistical analysis. Also, the groundwater hydrochemistry was investigated and classified using the Piper diagram. The study was developed from secondary data provided by the CPRM (Centro de Estudo Geológico do Brasil, previously Companhia de Pesquisa de Recursos Minerais. The geological formation of the Salgado basin has two aquifer systems, one on sedimentary rock (porous, karst and alluvial and another on (fractured crystalline rock. The research was conducted in 24 groundwater wells spread out over the drainage area of the basin, with data having been collected for the last 10 years. The water samples were analyzed for their content of Na+, K+, Ca2+, Mg2+, Cl-, CO3, HCO3 -, SO4 2- and CE. Two groups were formed by the use of cluster analysis, and both were independent with respect to their hydrological characteristics, and similar in hydro geological formation. The water quality study showed no temporal interference. The two components explained 78.30% of the total variance of the water quality. According to the Piper diagram, the waters were classified as 55.6% mixed chlorided water and 40% mixed bicarbonate water, in groups 1 and 2 respectively. The hydrochemical characterization of the studied waters implied no limitation to their human consumption.

  16. Mapeamento morfoestrutural e morfoescultural na região de cerrado no Norte de Minas Gerais / Morphostructural and morfoescultural mapping in the cerrado region in the North of Minas Gerais

    Directory of Open Access Journals (Sweden)

    Manoel Reinaldo Leite

    2012-04-01

    Full Text Available Este trabalho procurou compreender e mapear a configuração do relevo, referente ao 1º e 2º táxon da metodologia de Ross (1992, na microrregião de Montes Claros, através da aplicação das técnicas de geoprocessamento, de produtos orbitais e de informações colaterais, no intuito de promover, através de documentos cartográficos, o registro dos aspectos morfoestruturais e morfoesculturais referentes à morfologia desta microrregião. Estes objetivos se justificam uma vez que as unidades mapeadas fornecem informações fundamentais para a interpretação dos fenômenos geomorfológicos da área de estudo, contribuindo desta forma, para a analise destes terrenos a partir de levantamentos confiáveis de dados georreferenciados, possibilitando, assim, a espacialização e localização das feições geomorfológicas da presente microrregião. Os resultados das sobreposições em SIG de dados SRTM e dados geológicos da CPRM mostraram-se satisfatórios uma vez que possibilitaram a elaboração de uma vasta gama de informações sobre a área de estudo

  17. Molecular surveillance of dengue in Minas Gerais provides insights on dengue virus 1 and 4 circulation in Brazil.

    Science.gov (United States)

    Dutra, Karina Rocha; Drumond, Betânia Paiva; de Rezende, Izabela Maurício; Nogueira, Maurício Lacerda; de Oliveira Lopes, Débora; Calzavara Silva, Carlos Eduardo; Siqueira Ferreira, Jaqueline Maria; Dos Santos, Luciana Lara

    2017-06-01

    Dengue, caused by any of the four types of Dengue virus (DENV) is the most important arbovirus in the world. In this study we performed a molecular surveillance of dengue during the greatest dengue outbreak that took place in Divinópolis, Minas Gerais state, Southeast Brazil, in 2013. Samples from 100 patients with clinical symptoms of dengue were studied and 26 were positive. The capsid/premembrane (CprM) and envelope gene sequences of some samples were amplified and sequenced. Molecular analyses demonstrated that two DENV-1 lineages, belonging to genotype V were introduced and co-circulated in Divinópolis. When compared to each other, those lineages presented high genetic diversity and showed unique amino acids substitutions in the envelope protein, including in domains I, II, and III. DENV-4 strains from Divinópolis clustered within genotype IIb and the most recent common ancestor was probably introduced into the city three years before the 2013 epidemic. Here we demonstrated for the first time the circulation of DENV-4 and the co-circulation of two DENV-1 lineages in Midwest region of Minas Gerais, Brazil. Moreover our analysis indicated the introduction of five DENV-1 lineages, genotype V into Brazil, in different times. J. Med. Virol. 89:966-973, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. Identification of rice supply chain risk to DKI Jakarta through Cipinang primary rice market

    Science.gov (United States)

    Sugiarto, D.; Ariwibowo, A.; Mardianto, I.; Surjasa, D.

    2018-01-01

    This paper identifies several sources of risks in DKI Jakarta rice supply chain that through Cipinang Primary Rice Market (CPRM). Secondary data from several sources were collected and analysed using pareto chart and time series analysis. Based on the pareto analysis, it was known that there was a change in the order of suppliers whereas in 2011, 80% of the supply came only from Cirebon, Karawang and Bandung (West Java Province). While in 2015 the main source of supply changed to Cirebon, Central Java and Karawang. Linear trend equation using decomposition model for Cirebon and Karawang showed trend of decreasing monthly supply while Central Java had a positive trend. Harvest area of wetland paddy in Cirebon and Karawang showed a negative trend in the last 6 years. The data also showed that West Java Province was the province with the largest rice crop area affected by plant organism attack and drought disaster in 2015. DKI Jakarta had several potential supply chain risks from rice supply, drought risk and pests risk where the province of West Java, which previously could become a major supplier began to require supply assistance from other provinces, especially Central Java.

  19. Metallogenetic characterization of granitoid rocks through geochemical prospection: the Lagoa Real example related to uranium mineralization in Bahia state, Brazil; Caracterizacao metalogenetica de corpos gratinoides atraves de prospeccao geoquimica: o exemplo da suite intrusiva Lagoa Real relacionada a mineralizacoes de uranio no Estado da Bahia

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, J.E., E-mail: cprmsa@bahianet.com.br [Servico Geologico do Brasil (GEREMI/SUREG/SA/CPRM), Salvador, BA (Brazil)

    2011-07-01

    Within a broad metallogenetic evaluation program carried out by CPRM - Geological Survey of Brazil in covenant with the CBPM - Companhia Baiana de Pesquisa Mineral in the central part of the Sao Francisco Craton, the Lagoa Real granitoid rocks was one of the selected targets. The work included geochemical exploration supplemented by follow-in survey and integrated 1:200.000 scale geochemical cartography. The Lagoa Real granitoid was recognized with composition ranging from monzogranitic to alcaligranitic type. The geochemical surveying led to the definition of the metallogenetic specialization of the granitoid rock, with characteristic geochemical and mineralogic associations. These associations are related to uranium mineralization. The genetic model using stream sediment and pan concentrate data, show similarity with the metallogenetic model of zonal partitioning proposed by Routhier (1963), for plutonogenic lode deposits with potential for Sn, W, Nb, Be, REE, Au, and U. In this work emphasis is given to the importance of the integrated use of different prospective methods toward the evaluation of granitoid systems, particularly the combination of geochemical surveying methods with results for a better understanding of the geologic and metallogenetic settings. (author)

  20. Overview on the permanent magnets technology of rare earth based on Nd-Fe-B; Panorama general sobre tecnologia de imanes permanentes de tierras raras a base de Nd-Fe-B

    Energy Technology Data Exchange (ETDEWEB)

    Rosales Vazquez, Maria Ines [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    In this paper the technological development in the area of permanent magnetic materials, is shown, from the 1930`s when the first aluminum-nickel-cobalt (Al-Ni-Co) magnets appeared. As a result of the continuous worldwide research in this field, it was made known, during the 1980`s decade of a new type of magnets based on Neodymium (Nd). In accordance with the outstanding magnetic properties of these magnets, at the Instituto de Investigaciones Electricas (IIE), their development was initiated, focussed on the stages and parameters definition of their manufacturing process. Up to now, the research has been oriented to the preparation of magnets of the isotropic agglutinated type and the manufacturing process encompasses the following stages: a) Alloy preparation; b) Microcrystals obtainment; c) Magnet preparation. The preliminary results that have been obtained in the magnetic characterization show that the quality of the prepared magnets is comparable to the quality of the imported magnets and/or to the ones other research groups report. [Espanol] En este trabajo se muestra el desarrollo tecnologico del area de materiales magneticos permanentes a partir de los anos treinta en que surgieron los primeros imanes de aluminio-niquel-cobalto (Al-Ni-Co). Como resultado de la constante investigacion a nivel mundial en ese campo, durante el decenio de los ochenta se informo en torno a un nuevo tipo de imanes a base de neodimio (Nd). Atendiendo a las propiedades magneticas sobresalientes de estos imanes, en el Instituto de Investigaciones Electricas (IIE), se inicio el desarrollo de los mismos, enfocandolo a la definicion de las etapas y parametros del proceso de fabricacion. Hasta ahora, la investigacion se ha orientado a la preparacion de imanes de tipo isotropico aglutinado y el proceso de fabricacion comprende las etapas: a) preparacion de la aleacion; b) obtencion de microcristales, y c) preparacion de los imanes. Los resultados preliminares que se han obtenido en la

  1. QCD phase diagram under an external magnetic field

    Science.gov (United States)

    Ferreira, Marcio Rafael Baptista

    Neste trabalho e investigado o impacto de um campo magnetico externo na estrutura do diagrama de fases da Cromodinâmica Quântica (QCD). O estudo e realizado utilizando o modelo efetivo de Nambu-Jona-Lasinio para tres sabores acoplado ao loop de Polyakov (modelo de PNJL). A interacao de entanglement (modelo de EPNJL) na presenca de um campo magnetico e tambem estudada. Ambas as transicoes quiral e de desconfinamento na presenca de um campo magnetico externo podem ser analisadas usando os modelos de PNJL e EPNJL. Para o modelo de EPNJL e verificado que a coincidencia das temperaturas pseudocriticas de ambas as transicoes quiral e de deconfinamento dependem da parametrizacao da interacao de entanglement. E realizado um estudo sistematico do efeito de um campo magnetico externo nas transicoes quiral e de desconfinamento a potencial quimico barionico nulo, e.g., calculando a dependencia das temperaturas pesudocriticas com a intensidade do campo magnetico. O impacto de um campo magnetico externo no comportamento do quark estranho e analizado detalhadamente. E mostrado que a temperatura pseudocritica associada a transicao quiral do quark estranho e pouco sensivel a presenca de um campo magnetico externo. Alem disso, a sua grande massa corrente torna o quark estranho pouco sensivel ao termo de 't Hooft, contrariamente a forte influencia que tem nos quarks leves. Ambos os modelos de PNJL e EPNJL preveem o efeito de Catalise Magnetica a qualquer temperatura, mas nao reproduzem o efeito de Catalise Magnetica Inversa (CMI) em redor da temperatura pseudocritica de transicao, obtido em resultados recentes da LQCD. Mostramos que e possivel reproduzir a CMI se a intensidade da interacao entre quarks diminuir com o campo magnetico. Propomos dois mecanismos que reproduzem o efeito de CMI, que assumem o enfraquecimento da constante de acoplamento da interacao escalar com o aumento da intensidade do campo magnetico. O diagrama de fases e calculado para varios cenarios de isospin e

  2. Lanthanide oxide and phosphate nanoparticles for thermometry and bimodal imaging =

    Science.gov (United States)

    Debasu, Mengistie Leweyehu

    . Finalmente, estudam-se as propriedades de fotoluminescencia correspondentes as conversoes ascendente e descendente de energia em nanocristais de (Gd,Yb,Tb)PO4 sintetizados por via hidrotermica. A relaxividade (ressonancia magnetica) do 1H destes materiais sao investigadas, tendo em vista possiveis aplicacoes em imagem bimodal (luminescencia e ressonancia magnetica nuclear).

  3. Overview on the permanent magnets technology of rare earth based on Nd-Fe-B; Panorama general sobre tecnologia de imanes permanentes de tierras raras a base de Nd-Fe-B

    Energy Technology Data Exchange (ETDEWEB)

    Rosales Vazquez, Maria Ines [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    In this paper the technological development in the area of permanent magnetic materials, is shown, from the 1930`s when the first aluminum-nickel-cobalt (Al-Ni-Co) magnets appeared. As a result of the continuous worldwide research in this field, it was made known, during the 1980`s decade of a new type of magnets based on Neodymium (Nd). In accordance with the outstanding magnetic properties of these magnets, at the Instituto de Investigaciones Electricas (IIE), their development was initiated, focussed on the stages and parameters definition of their manufacturing process. Up to now, the research has been oriented to the preparation of magnets of the isotropic agglutinated type and the manufacturing process encompasses the following stages: a) Alloy preparation; b) Microcrystals obtainment; c) Magnet preparation. The preliminary results that have been obtained in the magnetic characterization show that the quality of the prepared magnets is comparable to the quality of the imported magnets and/or to the ones other research groups report. [Espanol] En este trabajo se muestra el desarrollo tecnologico del area de materiales magneticos permanentes a partir de los anos treinta en que surgieron los primeros imanes de aluminio-niquel-cobalto (Al-Ni-Co). Como resultado de la constante investigacion a nivel mundial en ese campo, durante el decenio de los ochenta se informo en torno a un nuevo tipo de imanes a base de neodimio (Nd). Atendiendo a las propiedades magneticas sobresalientes de estos imanes, en el Instituto de Investigaciones Electricas (IIE), se inicio el desarrollo de los mismos, enfocandolo a la definicion de las etapas y parametros del proceso de fabricacion. Hasta ahora, la investigacion se ha orientado a la preparacion de imanes de tipo isotropico aglutinado y el proceso de fabricacion comprende las etapas: a) preparacion de la aleacion; b) obtencion de microcristales, y c) preparacion de los imanes. Los resultados preliminares que se han obtenido en la

  4. A Test of the MSEC Method for Paleoclimate and intersite correlations from Late Pleistocene/Holocene cave sites in southern Europe : results from Cova de les Cendres, SE Spain

    Directory of Open Access Journals (Sweden)

    Brooks Ellwood

    2000-01-01

    Full Text Available En los ultlmos diez alios, se han utilizado las mediciones de la susceptibilidad magnetica (MS de los sedimentos de los yacimientos arqueologicos en cueva para establecer correlaciones entre yacimientos y una estimacion del paleoclima. Ello es posible porque la MS correspondiente a estos sedimentos es el resultado de los procesos activos del clima en el exterior de las cavidades y las variaciones en las propiedades magneticas de los sedimentos, que finalmente se acumulan en el interior de las cavidades. Una vez que se ban depositado, estos materiales son preservados y su estratigraffa proporciona una informacion sobre el clima que puede ser inferida. En este trabajo, al usar la magnetosusceptibilidad, el metodo de cicloestratigrafia (MSEC y la correlacion grafica, presentamos informacion sobre la Cova de les Cendres y situamos estos resultados en un marco paleoclimatico que abarca los ultimos 43.000 anos (fechas BP sin calibrar de la Europa meridional. Estos resultados correlacionan bien con otros indicadores independientes de clima. Ademas, a causa de que los sedimentos de la parte superior de la Cova de les Cendres se depositaron relativamente rapidos, es posible observar cambios climaticos de escala ultra-fina en los dates de esta parte de la secuencia en la cavidad.During the last 10 years or so, magnetic susceptibility (MS measurements of cave sediments from archaeological sites have been used for intra-site correlation and paleoclimate estimation. This is possible because the MS of these sediments results from climate processes active outside caves causing variations in magnetic properties of the sediments ultimately accumulating inside of caves. Once deposited, these materials are preserved and their stratigraphy provides a climate proxy that can be extracted. Here, using the magnetosusceptibility event and cyclostratigraphy (MSEC method and graphic correlation, we present data from Cova de les Cendres and place these results into a

  5. Cisticercosis diseminada: reporte de un caso en Perú

    Directory of Open Access Journals (Sweden)

    Julio Maquera-Afaray

    Full Text Available La cisticercosis es una enfermedad desatendida y endémica en el Perú que afecta comúnmente al sistema nervioso central (SNC, causando la neurocisticercosis (NCC. Sin embargo, son pocos los reportes de cisticercosis diseminada (CCD en el mundo. Se reporta el caso de un paciente varón de 82 años, natural del departamento de Junín, que presenta pérdida brusca del nivel de conciencia asociada a convulsiones tónico-clónicas generalizadas. La tomografía axial computarizada y la resonancia magnética nuclear cerebral mostraron múltiples lesiones de aspecto quístico con presencia de escólex en su interior y compatibles con NCC masiva; la resonancia magnética nuclear torácica, abdominal y pélvica permitieron evidenciar la diseminación multiorgánica de cisticercos. Aunque es poca la casuística y experiencia terapéutica en los casos de CCD, el paciente recibió tratamiento antiparasitario con albendazol y corticoides, logrando una evolución clínica favorable y sin complicaciones durante la hospitalización

  6. SHAPIRO EFFECT IN INDUCTIVE QUANTUM CIRCUITS WITH CHARGE DISCRETENESS EFECTO SHAPIRO EN CIRCUITOS CUÁNTICOS INDUCTIVOS CON CARGA DISCRETA

    Directory of Open Access Journals (Sweden)

    Kristopher Chandía Valenzuela

    2006-08-01

    Full Text Available ABSTRACT As it is known, quantum inductive circuits with charge discreteness show Bloch-like oscillations in electrical current under a dc external voltage. In this paper, the effect of a superimposed ac voltage in the circuit is considered. The Shapiro effect is found to be related to the existence of resonance. Surprisingly, in the limit of low frequency (no resonance, the electrical averaged current exists and has always the same sign. Eventually this allows for an experimental method to measure discrete charge effect in quantum mesoscopic circuits.RESUMEN Es sabido que circuitos cuánticos inductivos con carga discreta, cuando se someten a un voltaje continuo externo, presentan oscilaciones de Bloch en la corriente. En este trabajo se considera, además, la superposición de un voltaje alterno en el circuito. El efecto Shapiro, relacionado con la existencia de resonancias, es encontrado de modo explícito. Sorprendentemente, en el límite de bajas frecuencias (sin resonancia la corriente eléctrica promediada existe y tiene siempre el mismo signo. Eventualmente, esto entrega un método experimental para medir los efectos de la discretización de la carga en circuitos cuánticos mesosocópicos.

  7. Inversor Resonante de Tres Elementos L-LC con Caracteristica Cortocircuitable para Aplicaciones de Calentamiento por Induccion

    Science.gov (United States)

    Espi Huerta, Jose Miguel

    Los generadores de calentamiento por induccion son puentes inversores con carga resonante, cuya mision es basicamente crear una corriente sinusoidal de gran amplitud sobre la "bobina de caldeo", que forma parte del tanque resonante. En el interior de esta bobina se introduce la pieza que se desea calentar. EI campo magnetico creado induce corrientes superficiales (corrientes de Foucault) sobre la pieza, que producen su calentamiento. Los tanques resonantes (tambien llamados osciladores) utilizados en la actualidad son el resonante serie y el resonante paralelo. Aunque ya desde hace algun tiempo se vienen construyendo generadores de alta potencia basados en estos dos osciladores, el exito nunca ha. sido completo en ninguno de los dos casos. Tal y como se explica en la introduccion de esta memoria, los puentes inversores utilizados deben operar sobre una carga inductiva (corriente retrasada) para evitar el fenomeno de la recuperacion inversa de sus diodos y la consiguiente ruptura de los transistores. De la restriccion topologica anterior se deduce que el generador paralelo debe conmutar a frecuencias inferiores a la resonancia, y el serie a frecuencias superiores. A esta restriccion topologica hay que unir otra que es exclusiva del calentamiento por induccion: La corriente por la bobina de caldeo debe ser sinusoidal. De no ser asi, resultaria imposible disponer toda la potencia de calentamiento sobre la pieza en el espesor requerido por la aplicacion. Como consecuencia, los inversores no pueden operar por debajo de la frecuencia de resonancia del oscilador, pues en ese caso se amplifican los armonicos de orden superior de la tension/corriente de entrada situados sobre la resonancia, con la consiguiente distorsion de la corriente de salida. La conjuncion de las dos restricciones anteriores obligan al inversor paralelo a funcionar a la frecuencia de resonancia del oscilador. Esto imposibilita un control por variacion de frecuencia, regulandose la potencia desde la

  8. Non-destructive testing; Examenes no destructivos

    Energy Technology Data Exchange (ETDEWEB)

    Calva, Mauricio; Loske, Achim [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    The application of non-destructive testing (NDT) in several technical and industrial fields is pointed out, standing out its utilization in the detection of future failures without affecting the examined element. Likewise, the different types of NDTs and their processes, such as x-rays, ultrasoud, magnetic particles, induced currents, penetrating fluids, and optical means, are described. The Non-Destructive Tests Laboratory of the Instituto de Investigaciones Electricas (IIE), plans to create new and more reliable systems independent from the operator`s capacity, to contribute to fulfill the inspection and quality control needs of the generating Mexican power plants. [Espanol] Se senala la aplicacion de los examenes no destructivos (END) a diversos campos tecnicos e industriales, destacando su utilizacion en la deteccion de futuras fallas sin afectar el elemento examinado. Asimismo, se describen los diferentes tipos de END y sus procesos, tales como radiografia, ultrasonido, particulas magneticas, corrientes inducidas, liquidos penetrantes y metodos opticos. El Laboratorio de Pruebas no Destructivas, del Instituto de Investigaciones Electricas (IIE), planea crear sistemas novedosos mas confiables, que no dependan de la capacidad del operador, para contribuir a satisfacer las necesidades de inspeccion y control de calidad que se presentan en las plantas generadoras de energia mexicanas.

  9. Energy losses produced by differential currents in the metallic ducts of electric installations; Perdidas de energia producidas por corrientes diferenciales en la tuberia metalica de instalaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Campero L, Eduardo; Bratu S, Neagu; Marquez M, Luis; Caballero R, Rafael [Universidad Autonoma Metropolitana Unidad Azcapotzalco, Mexico, D. F. (Mexico)

    1994-12-31

    In this article it is explained what is known as differential currents and the conditions in which they appear in the electrical installations. A short outline is made on the magnetic induction phenomenon that appears in metallic conduits, due to the circulation of differential currents along the inside of the tube and that in turn produces energy losses in the form of heat, that is dissipated in the tube surrounding environment. The results of the measurements performed in the laboratory are shown in order to quantify the energy losses in the metallic conduit. It was found that for certain conditions these losses are significant. [Espanol] En este articulo se explica lo que se entiende por corrientes diferenciales y se describen las condiciones en las que estas aparecen en las instalaciones electricas. Se plantea brevemente el fenomeno de induccion magnetica que aparece en las tuberias metalicas, debido a la circulacion de corrientes diferenciales por el interior del tubo y que a su vez produce perdidas de energia en forma de calor, que se disipa en el ambiente que rodea al tubo. Se muestran los resultados de las mediciones que se llevaron a cabo en laboratorio para poder cuantificar las perdidas en tuberia metalica conduit. Se encontro que para ciertas condiciones estas perdidas son significativas.

  10. Non-destructive testing; Examenes no destructivos

    Energy Technology Data Exchange (ETDEWEB)

    Calva, Mauricio; Loske, Achim [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    The application of non-destructive testing (NDT) in several technical and industrial fields is pointed out, standing out its utilization in the detection of future failures without affecting the examined element. Likewise, the different types of NDTs and their processes, such as x-rays, ultrasoud, magnetic particles, induced currents, penetrating fluids, and optical means, are described. The Non-Destructive Tests Laboratory of the Instituto de Investigaciones Electricas (IIE), plans to create new and more reliable systems independent from the operator`s capacity, to contribute to fulfill the inspection and quality control needs of the generating Mexican power plants. [Espanol] Se senala la aplicacion de los examenes no destructivos (END) a diversos campos tecnicos e industriales, destacando su utilizacion en la deteccion de futuras fallas sin afectar el elemento examinado. Asimismo, se describen los diferentes tipos de END y sus procesos, tales como radiografia, ultrasonido, particulas magneticas, corrientes inducidas, liquidos penetrantes y metodos opticos. El Laboratorio de Pruebas no Destructivas, del Instituto de Investigaciones Electricas (IIE), planea crear sistemas novedosos mas confiables, que no dependan de la capacidad del operador, para contribuir a satisfacer las necesidades de inspeccion y control de calidad que se presentan en las plantas generadoras de energia mexicanas.

  11. Anomalous behavior of a confined two-dimensional electron within an external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Rosas, R; Riera R; Marin, J. L. [Universidad de Sonora, Hermosillo, Sonora (Mexico); Leon, H. [Instituto Superior Jose Antonio Echeverria, La Habana (Cuba)

    2001-10-01

    An anomalous diamagnetic behavior of a confined two-dimensional electron within an external magnetic field (perpendicular to the confining plane) is discussed in this letter. Although this finding is consistent with the pioneering work of Robnik, it has not been previously reported. When this effect occurs, the ratio between the typical length of spatial and magnetic confinement is an integer number. This property leads also to a quantization of the magnetic flux across the confining circle. The possible consequences of the peculiar behavior of the electron within such a structure are discussed. [Spanish] Se estudia una posible anomalia en las propiedades diamagneticas de un electron bidimensional confinado en presencia de un campo magnetico externo perpendicular al plano de confinamiento. Aunque los resultados obtenidos son consistentes con el trabajo pionero de Robnik, no han sido reportados anteriormente, a pesar de sus posibles aplicaciones, ya que cuando ocurre, el cociente entre la longitud magnetica y el tamano de la region de confinamiento es un numero entero, propiedad que establece una cuantizacion del flujo magnetico que atraviesa el circulo confinante. Se discuten las posibles consecuencias del comportamiento peculiar del electron en este tipo de estructura.

  12. Análise de agrupamento como suporte à gestão qualitativa da água subterrânea no semiárido cearense. = Cluster analysis as management support of groundwater quality in the Semiarid region of Ceará.

    Directory of Open Access Journals (Sweden)

    Francisco Bergson Parente Fernandes

    2010-12-01

    Full Text Available Entre os grandes desafios na gestão da qualidade das águas pode-se citar o elevado custo do monitoramento e a alta variabilidade espacial e temporal dos elementos determinantes da qualidade da mesma. Sendo assim, desenvolveu-se um estudo para identificar a similaridade das águas subterrâneas da bacia do Banabuiu com o objetivo de oferecer suporte ao monitoramento e a gestão da qualidade da água no semiárido cearense. Para tanto, empregou-se a técnica de estatística multivariada, análise de agrupamento em dados de qualidade de 66 poços cadastrados pelo Serviço Geológico do Brasil (CPRM. Foram investigados os seguintes atributos: Cálcio (Ca++, Cloreto (Cl-, Potássio (K+, Magnésio (Mg++, Nitrato(NO3-, Alumínio (Al+++, Sulfato (SO4-, Sódio (Na+ e Dureza Total. Os atributos investigados uniram os poços em três grupos estatisticamente distintos ao nível de significância de 5%. Os íons Cloreto, Magnésio, Potássio, Sódio e a Dureza Total foram determinantes na definição dos grupos. Para um nível de significância de 1% os grupos similares são definidos somente pelo Cloreto e o Potássio. Os resultados mostraram um bom potencial desta ferramenta no monitoramento e suporte a gestão da qualidade das águas em bacias hidrográficas no semiárido, pelo seu potencial em agrupar as amostras similares. = Among the challenges of water quality management can be cited the high cost of monitoring and the high spacial and temporal variability. Considering these points, a study of ground water quality similarity was developed with the aim to give a support in the management and monitoring water quality programs in the Banabuiu watershed, Ceará, Brazil. To do this, multivariate statistics was applied to a set of wells (66 registered at Serviço Geológico do Brasil (CPRM. We analyzed the following attributes: Calcium (Ca++, chloride (Cl-, Potassium (K+, Magnesium (Mg++, Nitrate (NO-3, Aluminum (Al+++, Sulphate (SO-4, Sodium (Na+ and

  13. PALEOENVIRONMENTAL EVOLUTION OF THE ITARARÉ GROUP (PARANÁ BASIN IN THE REGIONS OF SALTO AND ITU, EAST OF SÃO PAULO STATE, BRAZIL

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    Sérgio Bergamaschi

    2016-03-01

    Full Text Available Itararé Group represents the glacial record of Gondwana Continent in the intracratonic Paraná Basin, encompassing regions of Southern Brazil, Eastern Paraguay, Northeast Argentina and Northern Paraguay. Itararé Group is the thickest sedimentary package of Paraná Basin, and was deposited over 36 million years during the end of the Carboniferous and the beginning of the Permian. However, in relation to its paleoenvironmental evolution, it is generally understood that more research is necessary, in order to better understand the genesis of the Itararé Group in different places. The present work entailed mapping facies associations for the Itararé Group in the city of Salto, in São Paulo State, by identifying and classifying sedimentary facies that, in turn, were utilized to develop a paleoenvironmental evolution model. This model was based on geological mapping carried out over 125 km². Petrological and petrographic descriptions of 32 outcrops of Itararé Group also were studied. These results were compared with subsurface data obtained by Sistema de Informações de Águas Subterrâneas, Serviços Geológicos do Brasil (SIAGAS-CPRM; System Water Information Groundwater, Geological Survey of Brazil. Through lithofacies and petrographic analyses and making a comparison between five column sections, surface and subsurface data, a stratigraphic correlation model was established for the region. Through this model was possible to identify four facies associations, which, together, indicate how the paleoenvironmental evolution of the region occurred. The first three associations (A, B, C were interpreted as being formed in subaqueous environment, being related to sandy lobe systems, followed by the last association (D, pertaining to a fluvial system.

  14. Geoelectrical characterization with 1D VES/TDEM joint inversion in Urupês-SP region, Paraná Basin: Applications to hydrogeology

    Science.gov (United States)

    Leite, David Nakamura; Bortolozo, Cassiano Antonio; Porsani, Jorge Luís; Couto, Marco Antonio; Campaña, Julian David Realpe; dos Santos, Fernando Acácio Monteiro; Rangel, Rodrigo Corrêa; Hamada, Luiz Rodrigo; Sifontes, Rimary Valera; Serejo de Oliveira, Gabriela; Stangari, Marcelo César

    2018-04-01

    Although Brazil is well known by the large rivers and the Amazon Rain Forest most cities do not have access to sufficient quantities of surface water to supply the population. Because of this 61% of Brazilian population (IBGE, 2003) depends on groundwater resources. In order to help the conscious exploration of this resource in Urupês city (São Paulo State) which is characterized by problems of lack of water, this research applied the transient electromagnetic method (TDEM) and Vertical Electrical Sounding (VES) for the geoelectrical characterization of the interest region. So, the objective of this work was increase the hydrogeological basis for groundwater exploitation of Bauru sedimentary aquifer and Serra Geral fractured aquifer (Paraná Basin). A total of 23 TDEM and 15 VES soundings were conducted during the years of 2009, 2011 and 2012. In addition, 10 pairs of VES/TDEM soundings were acquired with coincident centers to be able to perform the joint inversion. The joint inversion technique is a promising tool, which enables to get the best of both methods, where the VES add the shallow information and TDEM the deeper one. In this work, the individual and joint inversions were performed using the "Curupira" software. After data process and inversion, the results were interpreted based on geological well information provided by the Department of Water and Electrical Power (DAEE) and the Brazilian Geological Survey (CPRM) which enabled to estimate favorable places to exploitation of water in Bauru and Serra Geral aquifers. For the Bauru aquifer, the results suggest areas where thickness exceeds 100 m. In these areas, the resistivity calculated was about 20 Ω·m. Therefore, the sediments have been interpreted as saturated sandy clay. In the basalt layer of Serra Geral Formation, the suggested locations present resistivity values sources for groundwater exploitation and water supply for Urupês city.

  15. Gamma-spectrometric surveys in differentiated granites. I: a review of the method and of the geochemical behavior of K, Th and U; Levantamentos gamaespectrometricos em granitos diferenciados. I: revisao da metodologia e do comportamento geoquimico dos elementos K, Th e U

    Energy Technology Data Exchange (ETDEWEB)

    Ulbrich, Horstpeter Herberto Gustavo Jose; Ulbrich, Mabel Norma Costas [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias. Dept. de Mineralogia e Geotectonica], e-mail: hulbrich@usp.br, e-mail: mulbrich@usp.br; Ferreira, Francisco Jose Fonseca [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Geologia. Lab. de Pesquisas em Geofisica Aplicada; Alves, Luizemara Soares [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)], e-mail: luizemara@petrobras.com.br; Guimaraes, Gilson Burigo [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil). Dept. de Geociencias], e-mail: gburigo@ig.com.br; Fruchting, Allan [Votorantim Metais, Sao Paulo, SP (Brazil)], e-mail: allan.fruchting@vmetais.com.br

    2009-07-01

    This contribution is part of a research project on the Neo proterozoic Cunhaporanga Granitic Complex (CGC), cropping out in the Ponta Grossa Arch (Parana state, SE Brazil). An initial study used the gamma-spectrometric data of the Serra do Mar Sul Aero geophysical Project, performed during the 70's for CPRM. Later, terrestrial gamma-spectrometric surveys focused on the study of the differentiated Joaquim Murtinho Granite (JMG) in the NW corner of CGC, and the Serra do Carambei Granite, to the SW. In this paper, the results obtained for JMG are presented in two parts. The first deals with methodology and the presentation of several gamma-spectrometric 'color-scale' maps, indicating that results obtained in granites depend strongly on a climatic factor, given the mobility of K during weathering in subtropical climates with strong rainfalls, also favoring a greater mobility of U. Minerals that are U and Th hosts, documented in granites, are reviewed, together with the weathering processes that control the mobility of K, U and Th in soils. Strong K signals in granitic areas submitted to these climates document the presence of fresh rock and/or effects of hydrothermal alteration, while weak or nil signals are evidence of strong leaching of K during weathering. U and Th will be retained in the residual soils, in part leading to their selective enrichment, also coupled with soil migration to lower topographic levels by colluvial transport. The larger solubility of U (as uranyl ion) allows its liberation under oxidizing conditions, and its migration, limited by the possibility of absorption in newly formed mineral and organic soil phases. Th should be retained almost totally in resistant phases and, when liberated in solution, will mostly be fixed in organic and inorganic soil substances. (author)

  16. Phylogenetic studies reveal existence of multiple lineages of a single genotype of DENV-1 (genotype III in India during 1956–2007

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    Bhattacharya D

    2009-01-01

    Full Text Available Abstract Background Dengue virus type 1 (DENV-1 have been mostly circulating silently with dominant serotypes DENV-2 and DENV-3 in India. However recent times have marked an increase in DENV-1 circulation in yearly outbreaks. Many studies have not been carried out on this virus type, leaving a lacunae pertaining to the circulating genotypes, since its earliest report in India. In the present study, we sequenced CprM gene junction of 13 DENV-1 isolated from Delhi and Gwalior (North India between 2001–2007 and one 1956 Vellore isolate as reference. For comparison, we retrieved 11 other Indian and 70 global reference sequences from NCBI database, making sure that Indian and global isolates from all decades are available for comparative analysis. Results The region was found to be AT rich with no insertion or deletion. Majority of the nucleotide substitutions were silent, except 3 non-conservative amino acid changes (I → T, A → T and L → S at amino acid positions 59,114 and 155 respectively in the Indian DENV-1 sequences, sequenced in this study. Except two 1997–98 Delhi isolates, which group in genotype I; all other Indian isolates group in genotype III. All Indian genotype III DENV-1 exhibited diversity among them, giving rise to at least 4 distinct lineages (India 1–4 showing proximity to isolates from diverse geographic locations. Conclusion The extensive phylogenetic analysis revealed consistent existence of multiple lineages of DENV-1 genotype III during the last 5 decades in India.

  17. O ACESSO GEOGRÁFICO AOS SERVIÇOS DE SAÚDE NA REGIÃO METROPOLITANA DE MANAUS E O PERFIL DA MORTALIDADE/Geographic access to health services in the metropolitan region of Manaus and the mortality profile

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    Larissa Cristina Cardoso dos Anjos

    2018-04-01

    Full Text Available A Região Metropolitana de Manaus (RMM está localizada no setor central da Amazônia, inserida no bioma da maior floresta tropical do planeta. Nessa paisagem, povos de diferentes culturas vivem e carecem de infraestrutura básica, serviços de educação e saúde. Considerando-se este contexto é apresentado neste artigo um estudo sobre o acesso geográfico aos serviços de saúde organizados na RMM. A análise incluiu: os aspectos do ambiente, a distribuição espacial dos serviços de saúde, os modais de transporte utilizados pela população em busca de atendimento a estes serviços e o perfil de mortalidade nos municípios que compõe a RMM. Os procedimentos metodológicos foram trabalhados por meio de levantamentos bibliográficos e documentais, dados secundários e cartográficos retirados do CPRM, DATASUS, DNIT e IBGE. Para apresentar o perfil de mortalidade da RMM foi calculada a taxa de incidência para cada município. De acordo com os resultados, observou-se que o acesso aos serviços de saúde, em todos os níveis de atenção, varia de acordo com a Geografia Física da região, sazonalidades fluviais e localização da população (urbana e rural. Esses aspectos podem ser relacionados com o perfil epidemiológico dos óbitos, cuja localização se conexa aos padrões de modais de transportes, assim como as mortes por causas mal definidas e o acesso fluvial ao serviço de saúde.

  18. Gamma-spectrometric surveys in differentiated granites. I: a review of the method and of the geochemical behavior of K, Th and U

    International Nuclear Information System (INIS)

    Ulbrich, Horstpeter Herberto Gustavo Jose; Ulbrich, Mabel Norma Costas; Guimaraes, Gilson Burigo

    2009-01-01

    This contribution is part of a research project on the Neo proterozoic Cunhaporanga Granitic Complex (CGC), cropping out in the Ponta Grossa Arch (Parana state, SE Brazil). An initial study used the gamma-spectrometric data of the Serra do Mar Sul Aero geophysical Project, performed during the 70's for CPRM. Later, terrestrial gamma-spectrometric surveys focused on the study of the differentiated Joaquim Murtinho Granite (JMG) in the NW corner of CGC, and the Serra do Carambei Granite, to the SW. In this paper, the results obtained for JMG are presented in two parts. The first deals with methodology and the presentation of several gamma-spectrometric 'color-scale' maps, indicating that results obtained in granites depend strongly on a climatic factor, given the mobility of K during weathering in subtropical climates with strong rainfalls, also favoring a greater mobility of U. Minerals that are U and Th hosts, documented in granites, are reviewed, together with the weathering processes that control the mobility of K, U and Th in soils. Strong K signals in granitic areas submitted to these climates document the presence of fresh rock and/or effects of hydrothermal alteration, while weak or nil signals are evidence of strong leaching of K during weathering. U and Th will be retained in the residual soils, in part leading to their selective enrichment, also coupled with soil migration to lower topographic levels by colluvial transport. The larger solubility of U (as uranyl ion) allows its liberation under oxidizing conditions, and its migration, limited by the possibility of absorption in newly formed mineral and organic soil phases. Th should be retained almost totally in resistant phases and, when liberated in solution, will mostly be fixed in organic and inorganic soil substances. (author)

  19. Laboratory and Molecular Characterization of Dengue Viruses in a 2014 Outbreak in Guangfo Region, Southern China.

    Science.gov (United States)

    Luo, Zhao-Fan; Hu, Bo; Zhang, Feng-Yi; Lin, Xiang-Hua; Xie, Xiao-Ying; Pan, Kun-Yi; Li, Hong-Yu; Ren, Rui-Wen; Zhao, Wen-Zhong

    2017-09-25

    Non-specific symptoms and low viremia levels make early diagnosis of dengue virus (DENV) infection challenging. This study aimed to i) identify laboratory markers that can be used to predict a DENV-positive diagnosis and ii) perform a molecular characterization of DENVs from the 2014 Guangdong epidemic. This retrospective study analyzed 1,044 patients from the Guangdong epidemic who were clinically suspected cases of dengue. Viral RNA was detected by real-time RT-PCR, and viral-specific NS1 antigen was detected using enzyme-linked immuno sorbent assay. A molecular phylogenetic analysis was performed for the with the DENV C-prM gene junction. Patients with dengue infection had leukopenia (2.8 × 10 9 /L), thrombocytopenia (109.0 × 10 9 /L), elevated aspartate aminotransferase (56.0 IU/L) and alanine aminotransferase (43.5 IU/L), and prolonged activated partial thromboplastin time (APTT, 33.5 s) (all P < 0.001) compared to patients without dengue. The positive predictive value of leukopenia and thrombocytopenia for DENV infection were 96.9% and 93.0%, respectively. Leukopenia, thrombocytopenia, elevated aminotransferases, and prolonged APTT were useful predictive markers for an early diagnosis of DENV infection. Phylogenetic analysis indicated that the DENVs from the 2014 epidemic were closely related to a 2010 New Delhi strain and a 2013 Guangzhou strain. The 2014 epidemic consisted of co-circulating DENV-1 genotypes I and V from multiple origins. Efficient dengue surveillance can facilitate rapid response to future outbreaks.

  20. Arturo Uslar Pietri: de renovador vanguardista a patriarca de la cultura nacional

    Directory of Open Access Journals (Sweden)

    Carlos Pacheco

    2014-06-01

    Full Text Available Si atendiendo a la cronología, apreciamos que nació en Caracas el 16 de mayo de 1906, que ya hacia 1920 publicaba sus primeros ensayos y algunos versos, y que hasta las proximidades de su muerte no dejó de ofrecer a la imprenta las muy diversas manifestaciones de su pluma, advertiremos que se trata de más de 80 años de sostenida y meritoria dedicación a la escritura literaria. Y también –valiéndose sobre todo de la prensa y la televisión en buena parte de este período– de una referencia crítica y orientadora de resonancia nacional, en momentos en que Venezuela vivió un vuelco cabal desde la gran hacienda gomecista hasta la modernidad petrolera y cosmopolita.

  1. SÍNTESIS DE OXITOCINA EN FASE SÓLIDA USANDO DERIVADOS DE TERBUTOXICARBONILO Y FLUORENILMETOXICARBONILO

    Directory of Open Access Journals (Sweden)

    Julio C Calvo

    2010-08-01

    Full Text Available La oxitocina, péptido cíclico cuya secuencia es CYIQNCPLG, fué el primer péptido de importancia biológica que pudo ser sintetizado. En este trabajo se compara la síntesis de la oxitocina usando resina p metilbenzhidrilamina (MBHA para la síntesis por estrategia t-Boc y resina Rink p-metilbenzhidrilamina (Rink MBHA para la síntesis por estrategia Fmoc, con altos rendimientos. El péptido crudo se ciclizó en una disolución acuosa de dimetilsulfóxido al 10%. La caracterización se llevó a cabo por espectrometría de masas y resonancia magnética nuclear, y se logró detectar la presencia de dos isómeros.

  2. Fibrilación auricular en una paciente con megaorejuela auricular izquierda

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    Alejandro Villamil

    2007-01-01

    Full Text Available La FA constituye una de las arritmias sostenidas más frecuentes que motivan la consulta. El sustrato comprende diferentes mecanismos, entre los que se encuentra el agrandamiento auricular izquierdo. Presentamos el caso de una mujer de 33 años con antecedentes depalpitaciones, que ingresó en la guardia por FA de alta respuesta ventricular. En la radiografía de tórax se observó una deformación del borde izquierdo de la silueta cardíaca. Posteriormente,el ecocardiograma transesofágico y la resonancia magnética nuclear evidenciaron una megaorejuela aneurismática debida, probablemente, a un defecto pericárdico. La conducta fue anticoagulación oral y tratamiento con atenolol, con evolución favorable.

  3. Encefalitis autoinmune en pediatría

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    Juan Carlos García-Beristáin

    2017-06-01

    Full Text Available La encefalitis es un desorden inflamatorio del encéfalo que deriva en un estado mental alterado, crisis convulsivas, déficits neurológicos focales, acompañado usualmente de signos de inflamación en el líquido cefalorraquídeo y hallazgos en la resonancia magnética que pueden ir desde normalidad hasta anormalidades extensas. La encefalitis puede ocurrir como resultado de una infección primaria del sistema nervioso central, o bien, por un proceso autoinmune desencadenado por una infección, vacuna o neoplasia oculta. La encefalitis autoinmune involucra varios tipos de entidades con diferentes fisiopatologías, el entender estas entidades nos ayuda a utilizar los recursos y elementos diagnósticos necesarios, así como la mejor estrategia terapéutica.

  4. Sartre y la crítica inglesa

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    Alfonso Hanssen

    1967-02-01

    Full Text Available Fuera de unos ensayos en revistas ("Times literary supplement", ('Esprit", "Les nouvelles littéraires", "Le Fígaro littéraire" y de alguno que otro libro de poca resonancia -pues no hemos visto que se imponga sobre los medios intelectuales- la crítica literaria formal sobre Sartre (no formalista ha sido realmente avara. En cambio, los órganos periódicos de expresión son insuficientes para tratar con el Sartre político, con el filósofo Sartre (la ensayística lo ha vulgarizado en razón del insistente uso de su terminología y con el Sartre revolucionario, el más conocido de todos, al parecer por los hechos y polémicas internacionales en que se ha puesto de protagonista.

  5. Reacción de ligandos azufrados con el complejo au2pt (ch2p(Sph24,cl2

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    Guillermo Garzón

    2010-07-01

    Full Text Available Se describe la reacción de intercambio del cloro en el complejo au2pt (ch2p(Sph24,cl2 por los ligandos SCH2Ph-,S2CN(CH2CH3,2- y SCN-. Los nuevos derivados azufrados se caracterizan por análisis químico, espectroscopia infrarroja, electrónica y resonancia magnética nuclear protónica. Los ligandos se coordinan por el azufre a los dos átomos sw oro metálico en forma simétrica. El análisis elemental concuerda con las estequiomctrías y estructuras propuestas.

  6. De un boom a otro: sobre realismos mágicos y gastronomías salvajes en Latinoamérica

    Directory of Open Access Journals (Sweden)

    Julio Hevia-Garrido-Lecca

    2013-10-01

    Full Text Available Tomando la lectura de Alejo Carpentier sobre lo real maravilloso en la narrativa latinoamericana y las apreciaciones que J. Goytisolo nos alcanza de la ensayística interdisciplinaria francesa, el artículo pone a prueba los alcances y limitaciones de la actual resonancia que tiene la gastronomía peruana. Ciertas prácticas orales cotidianas, como el comer y el beber, son consideradas en función de los diferentes capitales culturales que las envuelven. Entre tanto, caracteres etnográfi cos, tópicos microsociales y apelaciones literarias contribuyen a desmontar la colonización con que una mirada primermundista permea el marketing mediático en este orden de cosas.

  7. SÍNTESIS, CARACTERIZACIÓN E INCORPORACIÓN DE NANOPARTÍCULAS (ESFERAS Y BARRAS) DE AU EN LA MEZCLA (DONADOR/ACEPTOR) P3HT/PCBM CON POSIBILIDAD DE USO EN CELDAS FOTOVOLTAICAS ORGÁNICAS HÍBRIDAS

    OpenAIRE

    ADAME SOLORIO, JESÚS SALVADOR

    2017-01-01

    En este trabajo se reporta la síntesis y caracterización de nanopartículas de oro (NPs de Au), con morfología irregular, en medio acuoso mediante un método secuencial de crecimiento. Variando solo la cantidad de suspensión semilla de Au fue posible variar el tamaño y forma de las NPs de Au en función del volumen de la suspensión semilla de Au. Por otro lado, los polígonos irregulares presentan resonancia plasmónica de superficie (RPS) en la región del infrarrojo cercano, que favorece la separ...

  8. Intervalos de integración unificados para la caracterización estructural de petróleos, carbones o sus fracciones por rmn 1h y rmn 13c

    OpenAIRE

    Eliseo, Avella; Fierro, Ricardo

    2010-01-01

    Con base en la revisión de publicaciones, hechas entre 1972 y 2006, se evidenció que hay imprecisiones en los límites de los intervalos de integración que los autores asignan a las señales en resonancia magnética nuclear (RMN) para hacer la caracterización estructural de petróleos, carbones o sus fracciones derivadas, a partir de sus espectros de hidrógeno (RMN 1H) o de carbono (RMN 13C). En consecuencia, se determinaron límites unificados para la integración de los espectros RMN 1H y RMN 13C...

  9. El Quijote en un biombo novohispano del siglo XVIII

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    ARNULFO HERRERA

    2015-01-01

    Full Text Available Se hizo una revisión historiográfica sobre algunas de las resonancias de El Quijote en la vida cultural de la Nueva España. El análisis se centró en el examen de un biombo del siglo XVIII de autor desconocido en donde se plasmaron algunas de las escenas más importantes de la obra cervantina. Asimismo se plantearon dos hipótesis: primera, que tanto el estilo como el tópico del objeto se habrían convertido en una constante para este tipo de artículos suntuarios que proliferaron en las casas de los novohispanos pudientes, y segunda, que habría existido otro biombo novohispano con motivos iconográficos de la más famosa novela de Cervantes.

  10. ¿Qué pasa en el cerebro de los perros cuando ven caras humanas?

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    Laura V. Cuaya

    2016-05-01

    Full Text Available Cuando tu perro te ve, no sólo se iluminan sus ojos, también su cerebro. Aquí resumimos un experimento que realizamos para conocer el procesamiento cerebral de las caras humanas en perros, utilizando imágenes de resonancia magnética funcional, en el que encontramos actividad en la corteza temporal, frontal y el núcleo caudado. La actividad en la corteza temporal sugiere que los perros procesan las caras de manera similar a nosotros. Fue inesperado encontrar actividad en el núcleo caudado, porque sugiere que los perros procesan las caras humanas como recompensas, incluso si son caras de humanos desconocidos.

  11. Funcionalidad del sistema de neuronas espejo y su implicación en los procesos de aprendizaje motor por observación

    OpenAIRE

    Lago Rodríguez, Ángel

    2016-01-01

    [Resumen] El descubrimiento de las denominadas neuronas espejo, a comienzos de los años 90 del siglo XX, ha dado pie a la realización de un gran número de investigaciones en las que se han utilizado técnicas de examen neurofisiológico (p.ej.: Estimulación Magnética Transcraneal) y de neuroimagen cerebral (p.ej.: Resonancia Magnética Funcional) con el objeto de explorar cuáles son las funciones que desempeñan, cuales son las propiedades de los estímulos que logran activarlas, y en qué áreas ce...

  12. Oscilador para biosensores basado en microbalanza de cristal de cuarzo (QCM

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    Yeison Javier Montagut Ferizzola

    2011-01-01

    Full Text Available El cristal de cuarzo generalmente es usado en aplicaciones como microbalanza, aprovechando la capacidad que presenta éste para variar su frecuencia de resonancia de acuerdo a los cambios de la densidad superficial de masa depositada en la superficie del resonador. De esta manera, un cristal de cuarzo puede ser utilizado como transductor en un sistema de inmunosensor piezoeléctrico, para detectar uniones antígeno - anticuerpo. En este artículo se presenta una interfaz para microbalanzasde cristal de cuarzo, QCM (del inglés Quartz Crystal Microbalance basado en una versión mejorada de oscilador en configuración diferencial equilibrado y su validación como sistema de caracterización para biosensores. El sistema fue probado con éxito en un inmunosensor piezoeléctrico para la detección del plaguicida Carbaryl.

  13. Escleritis nodular posterior gigante compatible con sarcoidosis ocular simulando un melanoma de la coroides

    OpenAIRE

    Pérez-Campagne, E.; Guex-Crosier, Y.; Schalenbourg, A.; Uffer, S.; Zografos, L.

    2007-01-01

    Caso clínico: Un paciente de 30 años fue enviado a nuestro servicio oncológico de referencia con el diagnóstico de melanoma amelanótico de la coroides del ojo izquierdo. Se hicieron los siguientes exámenes: oftalmoscopía, angiografía fluoresceínica, angiografía con verde de indocianina, ecografía, resonancia magnética y biopsia. Discusión: El diagnóstico de escleritis nodular posterior gigante basado en la ecografía se confirmó mediante una biopsia. Se realizó un examen médico completo buscán...

  14. ABSCESO CEREBRAL MULTICÉNTRICO CAUSADO POR ENTAMOEBA HISTOLYTICA

    OpenAIRE

    CASTILLO DE LA CRUZ,MANUEL; JOSÉ LUIS,GALLEGOS BARREDO; MENDIZÁBAL GUERRA,RAFAEL; FÉLIX,IGNACIO; RIVAS,ANGÉLICA

    2004-01-01

    La infección amibiana del sistema nervioso central casi siempre es precedido de un absceso pulmonar o hepático. El absceso cerebral amibiano es raro y sólo se han publicado alrededor de 100 casos en el mundo. La mayoría de los reportes son de la era de la tomografía y hay muy pocos casos con imágenes de resonancia magnética, en ambos estudios, no puede diferenciarse de otro tipo de absceso. El diagnóstico es histopatológico y el tratamiento de elección es el metronidazol. Se reporta el caso d...

  15. La encrucijada en Pedro Páramo de Juan Rulfo / The Crossroads in Pedro Páramo by Juan Rulfo

    Directory of Open Access Journals (Sweden)

    Lilia Leticia García-Peña

    2015-08-01

    Full Text Available La obra de Juan Rulfo sintetiza la realidad del campo mexicano, captura el contorno de las identidades individuales y de la estructura de la interacción social del mundo que tanto le preocupó y del que es intérprete indiscutible, pero también supo convertir en materia narrativa aquellas atmósferas que rebasan el contexto mexicano y social. En este trabajo abordaré el tema de la encrucijada en el imaginario simbólico de Pedro Páramo (1955 como expresión de una reelaboración del mito de Hermes, analizaré cómo la novela de Juan Rulfo muestra estos ecos herméticos y qué sentido estético y sociocultural tiene esta resonancia mítica.

  16. Imaginología actual del cáncer pulmonar

    Directory of Open Access Journals (Sweden)

    Dr. D. Raúl Pefaur

    2013-01-01

    Los exámenes imaginológicos que en la actualidad se utilizan en el diagnóstico del cáncer pulmonar son la radiografía simple de tórax, la tomografía computada, la resonancia magnética y el PET-CT. En este artículo se analizará el rendimiento de estos exámenes en el diagnóstico y etapificación del cáncer pulmonar, así como la influencia de éstos en el tratamiento, pronóstico y evolución de esta enfermedad.

  17. El desafío bioético de la equidad: su relevancia en salud pública

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    Lolas Fernando

    2001-01-01

    Full Text Available Este trabajo presenta el discurso bioético como una incitación al diálogo entre convicciones, ideologías, racionalidades, disciplinas y personas. Entre sus temas dominantes, cabe distinguir aquellos que afectan a los colectivos y los que se refieren a los individuos. La equidad, aunque pertenece a los primeros, encuentra resonancias en el ámbito de las personas, especialmente bajo la forma de los principios de solidaridad y empatía. Distinguiendo entre valores, principios y reglas de conducta es posible formular algunas directrices para el trabajo de investigación en ciencias sociales y epidemiología que se apoyan en la noción de que la reflexión bioética debe anticipar los desafíos y no simplemente responder a los desarrollos tecnocientíficos.

  18. EL DESAFÍO BIOÉTICO DE LA EQUIDAD: SU RELEVANCIA EN SALUD PÚBLICA

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    Fernando Lolas

    2001-01-01

    Full Text Available Este trabajo presenta el discurso bioético como una incitación al diálogo entre convicciones, ideologías, racionalidades, disciplinas y personas. Entre sus temas dominantes, cabe distinguir aquellos que afectan a los colectivos y los que se refieren a los individuos. La equidad, aunque pertenece a los primeros, encuentra resonancias en el ámbito de las personas, especialmente bajo la forma de los principios de solidaridad y empatía. Distinguiendo entre valores, principios y reglas de conducta es posible formular algunas directrices para el trabajo de investigación en ciencias sociales y epidemiología que se apoyan en la noción de que la reflexión bioética debe anticipar los desafíos y no simplemente responder a los desarrollos tecnocientíficos.

  19. MR-DTI RICIAN DENOISING

    Directory of Open Access Journals (Sweden)

    ADRIAN MARTIN

    2013-01-01

    Full Text Available En este trabajo se trata el problema de eliminación de ruido Rician en imagen de Resonancia Magnética para la mejora de la reconstrucción de las imágenes de DifusiónTensorial. El modelado del ruido Rician es enfocado desde un marco variacional basado en el operador de Variación Total, convirtiéndolo en un problema de minimización de energía que conduce a la resolución de ecuaciones severamente no lineales. La solución propuesta es un algoritmo iterativo validado con imágenes sintéticas, que finalmente es probado en imágenes ponderadas en difusión reales.

  20. Síntesis y caracterización de nuevas nanopartículas de derivados de PBLG para su uso en nanomedicina

    OpenAIRE

    María Elisa Martínez Barbosa; An Young S. Taylor Castillo; Heriberto Acuña Campa; ian Arely Carrasco Cota

    2014-01-01

    En este trabajo se describe la realización de la síntesis y caracterización de cinco derivados de poli-L-glutamato de gamma-bencilo (PBLG) por polimerización aniónica de apertura de anillo utilizando iniciadores de interés biomédico, así como la preparación y caracterización de nanopartículas poliméricas preparadas usando los polímeros sintetizados. Los polímeros fueron caracterizados por resonancia magnética nuclear (RMN 1H) y cromatografía de exclusión de tamaño (GPC/SEC). Las nanopartícula...

  1. Presentación del Libro “Ibagué, Médicos y Medicina, 1941-1980”.

    Directory of Open Access Journals (Sweden)

    Efraim Otero Ruiz

    2007-03-01

    Pero la parte esencialmente biográfica es sólo la mitad de este precioso libro. Para situarnos en el ambiente que describe, como una “mise en scéne” de sus personajes, precede sus dos grandes capítulos períodos (1941-1960 y 1960-1980 con ilustradas y eruditas notas sobre Hospitales y Clínicas, Boticas, Farmacias y Droguerías, El Código de Policía y las Enfermedades de la época, Reseña de Música, de Gobernadores, de Alcaldes, de Eclesiásticos y los pone en paralelo (verdadera cronografía de doble columna con los acontecimientos médicos de mayor resonancia en el mundo...

  2. Aplicación de técnicas de diagnóstico por imagen avanzadas en el estudio de la cabeza del caballo

    OpenAIRE

    Manso Díaz, Gabriel

    2015-01-01

    La cabeza del caballo es una muy compleja anatómicamente lo que dificulta su diagnóstico. Por tanto las técnicas de diagnóstico por imagen son fundamentales.Las técnicas de diagnóstico por imagen avanzadas, resonancia magnética o RM y tomografía computarizada o TC, generan imágenes tomográficas, evitando la superposición de estructuras. La TC se basa en la rotación de un generador de rayos x y una matriz de detectores alrededor del paciente, mientras que la RM se basa en la excitación de teji...

  3. Tomografía cerebral, SPECT cerebral y neurocognición en trauma craneoencefálico

    OpenAIRE

    Casallo Quiliano, Carlos

    2013-01-01

    Introduccion: La tomografía cerebral (TC) es el examen de elección para evaluar un trauma cráneo encefálico (TCE) agudo. Otras pruebas, como la tomografía computarizada por emisión de fotón único (SPECT) están siendo utilizadas en el TCE, siendo mejor que la TC o la Resonancia magnética (RM) en la evaluación funcional del cerebro. La mayoría de estudios no incluyen, ni relacionan los resultados de la TC y SPECT con la evaluación neuropsicológica, la cual puede estar alterada a pesar de tener ...

  4. Hiperplasia hipofisaria secundaria a hipotiroidismo primario

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    Oscar Castillo

    2013-01-01

    Full Text Available Paciente mujer de 15 años referida por diagnóstico de hipotiroidismo e hiperprolactinemia, con tratamiento irregular para ambas patologías, quien presentó pérdida de conocimiento en dos oportunidades, motivo por el cual se le indicó resonancia magnética (RM de cerebro, en la cual se evidenció imagen tumoral hipofisaria que desplazaba el quiasma óptico. Se le indicó tratamiento con levotiroxina 50 ug por 1 semana, luego 100 ug diario. Los controles hormonales posteriores mostraron normalización, la RM de control evidenció disminución de tamaño de la imagen tumoral en aproximadamente 3 mm, sin repercusión en las estructuras supraselares o paraselares, con mejoría de cuadro clínico luego del tratamiento de sustitución con hormona tiroidea.

  5. Metástasis hipofisaria de carcinoma de mama debutando como diabetes insípida

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    Ana Arévalo

    2012-03-01

    Full Text Available Los tumores metastáticos que afectan a la glándula hipofisaria son hallazgos pocos comunes, presentándose en cerca del 1% de las cirugías hipofisarias. Los autores presentan el caso de una paciente mujer de 46 años que debuta con síntomas de diabetes insípida. Había sido tratada 3 años antes por un carcinoma ductal infiltrante de la mama derecha. Las imágenes de resonancia magnética cerebral mostraron una masa en la silla turca con extensión supraselar. La paciente fue sometida a resección tumoral vía transesfenoidal que demostró metástasis de carcinoma de mama.

  6. Lo contemporáneo en Clarice Lispector y Nuno Ramos. Ecos y apropiaciones

    Directory of Open Access Journals (Sweden)

    Mariela Herrero

    2016-01-01

    Full Text Available Se analizaron algunas obras de Clarice Lispector y del artista Nuno Ramos a fin de establecer un diálogo entre sus propuestas estéticas, así como para reconocer las resonancias o supervivencias que se extienden de una producción a otra. Se revisó de qué modo sus trabajos exceden y problematizan la categoría de obra, exhibiéndose a sí mismos como objetos errantes que tienden a una desidentificación de los soportes y materiales empleados para su producción y a una postproducción en su tratamiento.

  7. Teología literaria en El desbarrancadero de Fernando Vallejo

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    Juanita Cristina Aristizábal

    2012-07-01

    Full Text Available Este trabajo indaga en las resonancias modernistas en El desbarrancadero (2001 de Fernando Vallejo. Tomando como punto de partida las conexiones que la novela establece con Rubén Darío y Vargas Vila, propone que la escritura de Vallejo dialoga con varias de las coordenadas que marcaron la producción cultural en el periodo de entresiglos en América Latina y Europa. La lectura de la novela se ocupa de la forma que, un siglo más tarde, toman en el discurso de Vallejo temas como el simbolismo, la muerte de Dios, la sacralización de la poesía y la identidad nacional.

  8. Malformación arteriovenosa pancreática como causa de pancreatitis aguda tratada por vía endovascular

    OpenAIRE

    Kohan, Gustavo; Provenzano, Matías; Rosado, Martín; Farfan, Grisel; Sánchez, Nicolás; Fastman, Denise

    2017-01-01

    La malformación arterio-venosa (MAV) en el páncreas es una anomalía anatómica poco frecuente que puede ser causa de pancreatitis aguda. Presentamos el caso de un paciente de 46 años cuyo diagnóstico se sospechó por los hallazgos de la tomografía computarizada con contraste endovenoso y por resonancia magnética y se confirmó mediante una arteriografía del tronco celíaco y de la arteria mesentérica superior. El tratamiento recibido fue por vía endovascular, aunque la otra opción válida para el ...

  9. Medias miradas. Un análisis cultural de la imagen femenina (Enrique Gil Calvo

    Directory of Open Access Journals (Sweden)

    Mª Concepción Jimeno Calderón

    2008-05-01

    Full Text Available Enrique Gil Calvo nos ofrece un análisis de los signos visuales que se muestran en el escenario del anuncio publicitario como expresión de la identidad femenina. Para ello, a través de la observación de anuncios publicitarios impresos de distintas marcas de medias, como signo de distinción femenina (Medias Sely en 1933, Medias Eugenia de Montijo en 1960, Glory Complet en1964, Medias Balenciaga en 1966, Medias Helanca en 1980 estudia la repetición de los iconos y de los estereotipos utilizados, con una clara resonancia sexual (la mujer como objeto del deseo sexual masculino, como un transparente envoltorio de medias, dado el compulsivo fetichismo masculino y su dominio de la opinión pública.

  10. Fibrosis endomiocárdica

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    María Juliana Rodríguez-González

    2017-07-01

    Una de las formas más comunes de miocardiopatía restrictiva es la fibrosis endomiocárdica la cual es endémica en algunas zonas tropicales especialmente en África (países de bajos ingresos, pero en nuestro medio hay pocos reportes de aparición. Su etiología es desconocida, aunque existen diversos mecanismos que han sido involucrados en su fisiopatología. Su diagnóstico se basa en estudios imagenológicos (ecocardiograma transtorácico y resonancia magnética nuclear cardíaca. El pronóstico es muy pobre, y usualmente se diagnostica en etapas muy avanzadas de la enfermedad. Se describe el caso de una paciente femenina, adulta media, que debutó con cardiopatía restrictiva, cuyo diagnóstico final fue fibrosis endomiocárdica.

  11. Reto neuroquirúrgico actual del cordoma cervical

    Directory of Open Access Journals (Sweden)

    Héctor Figueredo Acosta

    2018-02-01

    Full Text Available El cordoma es un tumor osteocartilaginoso raro, de lento crecimiento, con una tasa de incidencia global de 8,4 casos por cada 10 millones de habitantes. Comúnmente aparece en la quinta y sexta década de la vida, predomina en el sexo masculino. Se presenta un paciente masculino de 47 años de edad, con cervicobraquialgia, cuadriparesia y masa tumoral palpable en región anterolateral del cuello. El estudio de resonancia magnética demostró la presencia de una lesión retrofraríngea con destrucción vertebral y compresión extradural. Se decidió resección quirúrgica de la lesión. El diagnóstico histopatológico por inmunohistoquímica arrojó como resultado, un cordoma.

  12. Malformación arteriovenosa uterina: A propósito de un caso

    OpenAIRE

    Badía Agustí, Paloma; Tamarit Bordes, Silvia; Alcover Barrachina, Inmaculada; Tamarit Bordes, Gemma; Pérez-Moneo Pérez, Patricia; Reyes Balanzá Chancosa, María

    2016-01-01

    Paciente de 37 años que acudió a urgencias por metrorragia, G3P1A2, el último de ellos un aborto tardío en gestación gemelar monocorial biamniótica de 20 semanas hacía dos meses. En la ecografía destaca en zona miometrial un área de marcada vascularización de 67 x 45 mm. Tras descartar proceso residual gestacional y ante la sospecha de malformación arteriovenosa uterina se solicitó resonancia magnética nuclear y angiotac, tras confirmar la malformación vascular se programó para embolización d...

  13. Síndrome de pinzamiento femoroacetabular en deportista veterano

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    F. Jiménez Borrero

    2015-12-01

    Full Text Available El síndrome de pinzamiento femoroacetabular (PFA es una patología común en el adulto joven deportista que cada vez está tomando más relevancia y que se caracteriza por una inadecuada relación femoroacetabular, con una clínica dolorosa e incapacitante de larga evolución, que puede simular otras patologías de la cadera, motivo por el cual, se debe realizar una anamnesis y una exhaustiva exploración física que nos oriente hacia esta patología, confirmando la sospecha diagnóstica mediante pruebas complementarias como la radiografía de pelvis y la resonancia magnética (RM. El tratamiento, en general, es quirúrgico. Debemos realizar un diagnóstico temprano ya que es una causa de artrosis precoz en el adulto joven.

  14. Neurofeedback y el malabarismo emocional

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    Antonio Rafael Hidalgo Muñoz

    2013-11-01

    Full Text Available Las bolas de malabares se equilibran sabiendo justo la bola que hay que lanzar y a qué velocidad se acercan unas a otras. ¿Y si controlásemos nosotros mismos nuestras emociones de la misma forma? La técnica de neurofeedback permite escrutar y manejar nuestros flujos vitales de tal manera que es posible reclutar nuestras propias redes neuronales, extrañamente desde fuera y desde dentro a la vez, dirigiéndolas según nos convenga. Al hilo de esta idea, la resonancia magnética funcional en tiempo real parece darnos una pista y servir como método de entrenamiento para regular nuestros estados afectivos.

  15. Pélope : la maduración de un "País"

    OpenAIRE

    Fernández Canosa, José A.

    1994-01-01

    En el mito de Pélope, el episodio de inequívocas resonancias iniciáticas en el que se narra la cocción a que éste es soinetido para "renacer aún más hermoso" y abrirle el acceso al matrimonio y a la realeza expresa en el dominio de lo culinario el paso de la naturaleza a la cultura. Si la cocción se revela como un método útil de para hacer pasar a un país a su estatus de adulto, se debe a que en el pensamiento griego existe a través de la teoría de la composición humoral, una a...

  16. Miedo al crimen, desigualdad y cambio social en México reflexiones a la luz de Durkheim y la Sociología de las emociones/Fear of crime, inequality and social change in Mexico reflextions in the light of Durkheim and the sociology of emotions

    Directory of Open Access Journals (Sweden)

    David Foust Rodríguez

    2011-08-01

    Full Text Available Este ensayo tiene el doble propósito de ser caja de resonancia de las intuiciones durkheimianas sobre la importancia de las emociones tanto en la sociología como en la socialidad misma, así como brindar una oportunidad para imaginar veredas para la investigación sobre las repercusiones sociales y políticas del miedo al crimen en México. En la primera parte expondremos algunas de las pistas que Durkheim ofreció en la línea de nuestros propósitos; en la segunda, amplificaremos esas pistas en la sociología de las emociones, particularmente con ayuda de Turner (2007; en la tercera parte retomaremos estas notas para explorar algunas ideas que pueden ayudar a hacer florecer la investigación sobre miedo al crimen, la desigualdad y el cambio social en México.

  17. Diseño y evaluación de un arreglo lineal de antenas miniaturizada para cubrimiento de pasillos

    Directory of Open Access Journals (Sweden)

    Jorge Enrique Ruíz García

    2012-01-01

    Full Text Available Este artículo describe el diseño y evaluación de un arreglo de dipolos impresos Broadside con alimentación en serie para aplicaciones WLAN. La técnica utilizada permite diseñar una antena de tamaño reducido ideal para radiar en pasillos, como los presentes en centros comerciales. La antena diseñada fue construida en tecnología tradicional conformada por substratos FR-4 y caracterizada por medio de una cámara anecoica, comprobando su efectividad para la banda de 2.4 GHz. Los resultados experimentales difieren solo 1.18 dBi con respecto a la ganancia máxima y 1.7% con respecto a la frecuencia de resonancia diseñada.

  18. Lesiones cerebrales en áreas limítrofes e infartos hemodinámicos. Evaluación con imágenes diagnósticas

    Directory of Open Access Journals (Sweden)

    Julio Mario Araque G.

    1999-04-01

    Full Text Available La clasificación de los infartos cerebrales, desde el punto de vista de las imágenes diagnósticas, se basa fundamentalmente en la localización, tamaño y forma en que se evidencia el daño parenquimatoso en los estudios de Resonancia Magnética (RM o de Tomografía Axial Computadorizada (TAC (1,2. Con los mencionados exámenes se pueden diferenciar infartos territoriales de infartos limítrofes, lo cual tiene implicaciones pronósticas y de tratamiento, pues las lesiones en áreas limítrofes implican un compromiso más severo de la hemodinámica global del paciente (3 y se asocian frecuentemente a lesiones significativas de vasos intra o extracraneanos o enfermedad sistémica.

  19. Identification of Close Vibration Modes of a Quasi-Axisymmetric Structure: Complementary Study

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    Cortés-García Claudia

    2013-04-01

    Full Text Available Se presenta un procedimiento para la caracterización de modos de vibración estructural conocidos como “modos cercanos”, que son aquellos con frecuencias naturales similares y que se presentan comúnmente en estructuras cuasi-axisimétricas.La caracterización de estos modos normalmente se dificulta debido a que sus regiones de resonancia están traslapadas, y eso impide distinguir las componentes de vibración correspondientes a cada modo empleando los métodos convencionales, diseñados para sistemas de un grado de libertad.El procedimiento que se propone aquí se basa en la estimación simultánea de los parámetros de dos modos cercanos empleando el número mínimo posible de datos de respuesta en el dominio de la frecuencia. Los parámetros modales se relacionan directamente con las diferencias entre la respuesta medida a diferentes frecuencias de excitación. La contribución principal de este trabajo es un método de caracterización modal diseñado específicamente para identificar los parámetros de pares de modos cercanos de vibración, que a diferencia de los métodos establecidos de análisis no requiere que la respuesta en cada resonancia esté dominada por un solo modo. La aplicación del procedimiento a una estructura real demuestra que es posible estimar los parámetros modales asociados con modos cercanos de un sistema empleando un número reducido de datos de su respuesta vibratoria, y proporciona resultados satisfactorios aún en presencia de ruido en las mediciones.

  20. LIPOMA CEREBRAL EN CUERPO CALLOSO: HALLAZGO INCIDENTAL EN PACIENTE CON EVENTO CEREBROVASCULAR

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    Gloria Cárcamo-Portillo

    2016-07-01

    Full Text Available Los lipomas intracraneales son lesiones infrecuentes y benignas que representan el 0,03 al 0,08% de todas las masas intracraneales. Estos se encuentran relacionados a un defecto de la línea media debido a un mal cierre del tubo neural; lo que conlleva a una mala diferenciación y una persistencia anormal de la meninge primitiva con posterior diferenciación al tejido adiposo. La mitad de los casos permanecen asintomáticos y son diagnosticados como un hallazgo incidental en los estudios imagenológicos. Sin embargo, otros casos se asocian a sintomatología neurológica como retraso psicomotor, cefalea, epilepsia y parálisis cerebral. Se presenta el caso de una paciente de 46 años de edad, con antecedentes de hipertensión arterial y diabetes mellitus tipo 2; que cursa con sintomatología de Evento Cerebrovascular Isquémico por lo que le realizan –una Tomografía Computarizada (TC y una Resonancia Magnética (RM. En el reporte se describen múltiples infartos a nivel del hemisferio cerebral izquierdo mientras que al nivel de la línea media se observó una imagen compatible con lipoma cerebral que afectaba el rostro, la rodilla y la porción anterior del cuerpo calloso. La identificación de este hallazgo fue incidental. Palabras claves: Lipoma Cerebral; Cuerpo Calloso; Resonancia Magnética; Accidente Cerebrovascular. (Fuente: DeCS BIREME.

  1. Caracterización etiológica del síndrome de Lennox-Gastaut sintomático

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    Ileana Valdivia Álvarez

    2012-03-01

    Full Text Available Introducción: el síndrome de Lennox-Gastaut es una encefalopatía epiléptica dependiente de la edad, de gran severidad, por su farmacorresistencia y las discapacidades asociadas. Objetivos: caracterizar el síndrome de Lennox-Gastaut sintomático según sexo, edad de inicio y diagnóstico, tipo de crisis predominantes, hallazgos en neuroimagen y etiología. Métodos: estudio descriptivo, retrospectivo con una muestra de 36 pacientes egresados del servicio de neuropediatría del Hospital Pediátrico "Juan M. Márquez", con diagnóstico de síndrome de Lennox-Gastaut sintomático y que tuvieran estudios de neuroimagen (tomografía axial computarizada y resonancia magnética nuclear. Las variables cualitativas se describieron estadísticamente mediante frecuencias absolutas y cifras porcentuales. Para los porcentajes de interés, se calculó su intervalo de confianza con el 95 % de confiabilidad (IC 95 %. Resultados y conclusiones: el síndrome de Lennox-Gastaut sintomático fue más frecuente en varones, que comenzaron con epilepsia antes del año de edad, el 33 % presentó síndrome de West. Más del 60 % se diagnosticó antes de los 4 años de edad. Las crisis más frecuentes fueron las tónicas y atónicas de cuello. La tomografía axial computarizada permite localizar zonas de atrofia y pocas lesiones estructurales, que se precisan por resonancia magnética nuclear como alteraciones de la migración neuronal. Después de las malformaciones del sistema nervioso central, la causa más frecuente fue la hipoxia perinatal.

  2. Computational package for the dynamic analysis of synchronous generators and their controls; Paquete computacional para el analisis de generadores sincronos y sus controles

    Energy Technology Data Exchange (ETDEWEB)

    Perez Guillen, Jesus Artemio

    1997-12-31

    conjunto de simuladores de los elementos que integran el subsistema de generacion. El desarrollo de la interfaz grafica se realizo con programacion orientada a objetos utilizando la libreria de clases para aplicaciones en medio ambiente Windows, proporcionada por el compilador de Borland C++, generando un conjunto de menus y ventanas de dialogos que integran un medio ambiente de simulacion interactivo y versatil. El paquete contiene modelos matermaticos de tercero, cuarto, quinto y sexto orden para generadores sincronos de polos lisos y polos salientes; incluye los modelos matematicos de los sistemas de excitacion DC1A, AC1A y ST1A de la clasificacion del IEEE; modelos de turbinas termica e hidraulica con gobernador de velocidad; se incluye un modelo matematico para el estabilizador de sistema de potencia y los efectos de la saturacion magnetica en los generadores sincronos. La solucion de las ecuaciones diferenciales puede realizarse por cuatro metodos de integracion numerica. Euler, Euler mejorado y Runge Kutta de segundo y cuarto orden. Tambien se incluyen algoritmos para la generacion grafica del diagrama fasorial, curva de capacidad y curva de saturacion de la maquina sincrona. Se presentan resultados de simulaciones para verificar la influencia en la respuesta dinamica del sistema de los metodos numericos de integracion, del modelado de la maquina sincrona, de los sistemas de excitacion, del estabilizador del sistema de potencia y de la saturacion magnetica del generador sincrono. Con la integracion de la interfaz grafica, el conjunto de simuladores para los distintos elementos del sistema de generacion de potencia indicados y el conjunto de herramientas de analisis grafico se obtiene un paquete de computo que puede ser util para la ensenanza e investigacion de la dinamica de los generadores sincronos y sus controles.

  3. Investigations on the nature and physical concentration of Spanish uraniferous quartzites; Estudios de caracterizacion y concentracion fisica de cuarcitas uraniferas espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Lora, F de [Direccion de Plantas Piloto e Industriales, Junta de Energia Nuclear, Madrid (Spain)

    1967-06-15

    A study was made of a sample of radioactive material from Santa Elena (Jaen) containing 130 ppm U{sub 3}O{sub 8}, 300 ppm ThO{sub 2}, 4.96% ZrO{sub 2} and 14.29% TiO{sub 2}. Over 150 million tons of material were examined. In the light of the studies carried out the material can be defined as a rutilo-zirconiferous quartzite with a double radioactivity source due to the uranium enclosed in the zircon lattice structure and to the presence of monazite. The possibility of brannerite or davidite being present can be discarded. There is likewise no conclusive evidence of the presence of sphene, rutile being the most abundant titanium mineral. The author determined the features of the ore with a view to its physical concentration and applied magnetic and gravimetric separation and the flotation process. The use of oleic acid as collector has permitted good zircon recovery. (author) [Spanish] Se ha estudiado una muestra de material radiactivo procedente de Santa Elena (Jaen) con 130 ppm de U{sub 3}O{sub 8}, 600 ppm de ThO{sub 2}, 4,96% de ZrO{sub 2} y 14,29% de TiO{sub 2}. El material examinado es considerable: mas de 150 millones de toneladas. De acuerdo con los estudios realizados se puede definir como una cuarcita rutilo-circonifera con dos fuentes de radiactividad debidas al uranio englobado en la red del circon y a la presencia de monacita. Se descarta la posibilidad de existencia de brannerita o davidita. Tampoco existen pruebas concluyentes de que contenga esfena, siendo el ratilo el mineral de titanio mas abundante. Se han determinado las caracteristicas de la mena con vistas a su concentracion fisica. Se ha ensayado la separacion magnetica, gravimetrica y flotacion. El empleo de acido oleico, como colector, ha dado buenas recuperaciones de circon. (author)

  4. Design and implementation of the 40, 50/51 protections and MEL, OEL and V/HZ limiters in a synchronous generator; Diseno e implementacion de las protecciones 40,50/51 y limitadores MEL, OEL y V/HZ en un generador sincrono

    Energy Technology Data Exchange (ETDEWEB)

    Goitia Ochoa, Salvador Hector

    2001-10-15

    The thesis shows the design and implementation of loss of field (40) and overcurrent (50/51) relays, minimum excitation limiter (MEL), over excitation limiter (OEL) and Voltage / Frequency limiter (V/Hz). It is also shown the development of a synchronous machine mathematical model for representing the conditions of open circuit, three phase short-circuit at stator terminals and short/open circuit at the field winding. Finally, a study about the magnetic saturation effect on the protection against loss of excitation is shown. It is studied the effects on the relay settings by using the X{sub d} saturated reactance. All the tests were applied for a salient-pole synchronous machine of 7 kVA, 220 V and 1800 rpm. The machine is at the Propulsion Laboratory of the Instituto Tecnologico de La Laguna. [Spanish] En este trabajo de tesis se realiza el diseno e implementacion de las protecciones contra la perdida de campo (40) y de sobrecorriente (50/51), asi como el de los limitadores de minima excitacion (MEL), maxima excitacion (OEL) y el limitador de Voltaje / Frecuencia (V/Hz). Ademas se muestra el desarrollo de las ecuaciones del modelo matematico del generador sincrono en condiciones de circuito abierto, con una falla trifasica en terminales, con el devanado de campo en corto circuito y en circuito abierto. Por ultimo se realiza un estudio en el cual se incluye el efecto de la saturacion magnetica en la proteccion contra la perdida de campo y las consecuencias que traeria el ajustar la proteccion usando el parametro de X{sub d} saturada. Las pruebas fisicas de las protecciones y limitadores fueron aplicadas a un generador sincrono de polos salientes con una capacidad de 7 kVA, 220 V, 1800 rpm, localizado en el Laboratorio de Propulsion de Instituto Tecnologico de la laguna.

  5. The corrosion behaviour of nanograined metals and alloys

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    Herrasti, P.

    2012-10-01

    Full Text Available There has been considerable interest in the properties of nanocrystalline materials over the last decade. Such materials include metals and alloys with a crystal size within the order of 1 to 100 nm. The interest arises due to the substantial differences in electrical, optical and magnetic properties and also due to their high adsorption capability and chemical reactivity compared to their larger grained counterparts. In this paper, the corrosion of nanocrystalline metals and alloys is investigated and compared to the corrosion of microcrystalline materials having a similar composition. The focus is on the corrosion of nickel, copper, cobalt and iron alloys. Key aspects of different corrosion behaviour such grain boundaries and size are identified.

    En la última década ha habido un gran interes en las propiedades de materiales nanocristalinos. Estos materiales incluyen metales y aleaciones con un tamaño de cristal del orden de 1 a 100 nm. El interes por estos materiales es debido a las grandes diferencias en cuanto a sus propiedades electricas, opticas y magneticas, asi como a su alta capacidad de adsorción y reactividad química en relación a los mismos materiales con tamaños de grano mayores. En este trabajo se ha investigado y comparado la corrosión de materiales nano y microcristalinos de similar composición química. Principalmente se ha centrado en la corrosión de metales tales como niquel, cobre, cobalto y aleaciones de hierro. Se ha comprobado que los diferentes comportamientos frente al proceso de corrosión están intimamente ligados con los bordes de grano y el tamaño de dichos granos.

  6. Nuclear magnetic resonance analysis of freeze-thaw damage in natural pumice concrete

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    Wang, Xiaoxiao

    2016-06-01

    Full Text Available This paper presents an analysis of the damage propagation features of the pore structure of natural pumice lightweight aggregate concrete (LWC under freeze-thaw cyclic action. After freeze-thaw cycling, we conducted nuclear magnetic resonance (NMR tests on the concrete and acquired the porosity, distribution of transverse relaxation time T2, and magnetic resonance imaging (MRI results. The results showed the following. The T2 distribution of the LWC prior to freeze-thaw cycling presented four peaks representative of a preponderance of small pores. After 50, 100, 150, and 200 freeze-thaw cycles, the total area of the T2 spectrum and the porosity increased significantly. The MRI presented the changing spatial distribution of pores within the LWC during freeze-thaw cycling. Ultrasonic testing technology was applied simultaneously to analyze the NMR results, which verified that the new NMR technology demonstrated high accuracy and practicability for research regarding freeze-thaw concrete damage.En este trabajo se analiza la propagación de los daños que se producen en la estructura porosa de hormigón aligerado a base de piedra pómez natural sometido a la acción cíclica de hielo-deshielo. Después de realizarse los ensayos de hielo-deshielo, el hormigón se analizó mediante resonancia magnética nuclear (RMN, determinándose la porosidad y la distribución del tiempo de relajación transversal, T2, y registrándose las imágenes captadas por resonancia magnética. De acuerdo con los resultados obtenidos, antes de los ciclos de hielo-deshielo la distribución de T2 del hormigón aligerado presentaba cuatro picos, indicativos de un predominio de poros pequeños. Después de que se sometiera a 50, 100, 150, y 200 ciclos, se observó un aumento importante tanto de la porosidad como de la superficie total del espectro de T2. Las imágenes captadas por resonancia magnética evidenciaron la modificación de la distribución espacial de los poros del

  7. Compromiso neuronal en esclerosis múltiple Neuronal injury in multiple sclerosis

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    Jorge Correale

    2006-10-01

    Full Text Available La esclerosis múltiple (EM ha sido considerada clásicamente como una enfermedad desmielinizante. Si bien el compromiso neurodegenerativo fue previamente descripto, sólo recientemente ha sido enfatizado. Por estudios recientes se ha identificado la degeneración axonal como el mayor determinante de discapacidad neurológica irreversible en pacientes con EM. El daño axonal se inicia tempranamente y permanece silente durante años, la discapacidad neurológica se desarrolla cuando se alcanza cierto umbral de pérdida axonal y los mecanismos de compensación se agotan. Se han propuesto tres hipótesis para explicar el daño axonal: 1 El daño es causado por un proceso inflamatorio, 2 Existe una excesiva acumulación de Ca2+ intraaxonal, 3 Los axones desmielinizados evolucionan a un proceso degenerativo producto de la falta de soporte trófico provisto por la mielina o células formadoras de mielina. Si bien la EM fue tradicionalmente considerada como una enfermedad de la sustancia blanca, el proceso de desmielinización también ocurre en la corteza cerebral. Las lesiones corticales muestran injuria neuronal representada por transección de axones y dendritas, así como apoptosis de neuronas. Dado que los métodos convencionales de resonancia magnética nuclear (RMN son limitados en su capacidad para brindar información sobre el compromiso axonal en EM, procedimientos como tensor de difusión, espectroscopia por resonancia magnética, resonancia magnética funcional, y nuevas técnicas para medir atrofia han sido desarrollados recientemente para monitorear su evolución. El reconocimiento de que EM es en parte un proceso neurodegenerativo impone abordar de manera crítica la patogenia de la enfermedad, a fin de considerar nuevas estrategias de tratamiento.The concept of multiple sclerosis (MS as a demyelinating disease is deeply ingrained. Although the existence of a neurodegenerative component has always been apparent, it has only recently

  8. PARAMETERIZED LAYOUT SYNTHESIS OF A CMOS-COMPATIBLE SCANNING MICROMIRROR WITH ELECTROTHERMAL ACTUATION AND BIMODAL RESONANT BEHAVIOR

    Directory of Open Access Journals (Sweden)

    Sergio Camacho León

    2011-01-01

    Full Text Available Este trabajo presenta una metodología de síntesis de parámetros para la automatización del diseño de un microespejo de escaneado compatible CMOS con comportamiento resonante bimodal. El microespejo está suspendido por actuadores térmicos bimorfos en voladizo con accionamiento fuera del plano. La metodología propone la optimización de espesores y el escaneo en el segundo modo de resonancia como estrategias para superar el conflicto característico entre el desempeño estático y dinámico del dispositivo. El objetivo es obtener automáticamente los parámetros de diseño del dispositivo que, de manera concurrente, maximizan el ángulo de rotación, minimizan el consumo de energía y satisfacen tanto las limitaciones de fabricación de un proceso CMOS estándar como las especificaciones de alto nivel para la posición del eje de rotación en el segundo modo de resonancia, la frecuencia de escaneado y el voltaje máximo de actuación. La metodología utiliza un espacio de diseño de nivel intermedio, definido por la razón de resistencia térmica a resistencia eléctrica del dispositivo a temperatura ambiente, para acoplar las restricciones del esfuerzo térmico máximo con la densidad de corriente eléctrica máxima de los materiales CMOS. El procedimiento de evaluación de funciones objetivos se desarrolla sobre la base de un modelo de elementos concentrados de la resistencia térmica del dispositivo para explorar sistemáticamente el espacio de diseño utilizando variaciones paramétricas. La metodología se aplica para diseñar un microescáner que tiene aplicaciones en sistemas imagenológicos de coherencia óptica. El desempeño del microescáner sintetizado es verificado por simulaciones mediante el método de elementos finitos. Los resultados obtenidos numéricamente presentan un buen ajuste con las especificaciones de alto nivel.

  9. COMPORTAMIENTO ESTRUCTURAL DE LOS ÁCIDOS HÚMICOS OBTENIDOS DE UN SUELO ANDISOL DEL DEPARTAMENTO DEL CAUCA

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    Carmen Mosquera

    2008-04-01

    Full Text Available Las sustancias húmicas del suelo constan de una mezcla heterogénea de compuestos, en la que cada fracción (ácidos húmicos, ácidos fúlvicos y huminas está constituida por moléculas de tamaños diferentes, y su estructura depende considerablemente tanto de los materiales orgánicos presentes en el suelo, como de las diferentes condiciones ambientales. Este estudio, empleó técnicas de espectroscopía ultravioleta – visible (relación E4/E6, infrarroja con transformada de Fourier  y resonancia magnética nuclear 13C (RMN para identificar la estructura química de una muestra de ácidos húmicos (AH provenientes de un suelo agrícola del departamento del Cauca, y los cambios que dicha estructura presenta en diferentes medios de reacción, como en anhídrido acético y alcohol absoluto. Los AH se obtuvieron a partir de la materia orgánica del suelo, mediante una separación granulométrica del suelo y una extracción sucesiva empleando tres soluciones básicas: tetraborato de sodio (0,05M, pirofosfato de sodio (0,05M e hidróxido de sodio (0,1M, purificándolos a través de tratamientos ácidos HCl-HF 1%, centrifugación de alta velocidad y diálisis. La relación E4/E6 mostró cambios en el grado de condensación de los AH en los diferentes medios de reacción, corroborándose dichos cambios por el aparecimiento de nuevas bandas o disminución y aumento de otras en los espectros infrarrojos, y por los cambios apreciables en las bandas y distribución de la intensidad en las diferentes regiones de los espectros de resonancia magnética nuclear 13C. Esta investigación  muestra cambios químicos y estructurales de los ácidos húmicos extraídos de un suelo agrícola, que  concuerdan con diferentes investigaciones efectuadas en este campo.

  10. Early diagnosis of Balo's concentric sclerosis by diffusion tensor tractography: a case report and literature review

    Directory of Open Access Journals (Sweden)

    Juan Alberto Nader Kawachi

    2016-03-01

    Full Text Available La esclerosis concéntrica de Baló es una variante infrecuente de enfermedad desmielinizante relacionada con la esclerosis múltiple, inicialmente considerada de progresión fatal. En estudios recientes se reportan variantes no fatales de esclerosis concéntrica de Baló en los que se enfatiza la importancia del diagnóstico por medio de la imagen por resonancia magnética, utilizando además la espectroscopia y las secuencias de difusión y perfusión. En los últimos años se ha logrado reproducir la imagen tridimensional de un fascículo en particular y observar la presencia de lesiones por medio de la tractografía por imagen por resonancia magnética mediante la técnica de tensor de difusión. Presentamos el caso de una mujer joven con síntomas neurológicos focales agudos, incluyendo paresia de extremidades derechas, cuyo diagnóstico por biopsia fue de esclerosis concéntrica de Baló, confirmando el resultado de los estudios de imagen. La paciente recibió tratamiento con bolos de metilprednisolona, obteniendo remisión clínica completa a largo plazo. A nuestro entender, este es el primer reporte que describe los hallazgos de la esclerosis concéntrica de Baló utilizando la técnica de tensor de difusión. Consideramos que dicha técnica permitirá en el futuro la detección temprana de la enfermedad, su tratamiento oportuno y permitirá establecer nuevos criterios de clasificación y estratificación. Este caso demuestra la existencia de variantes benignas de esclerosis concéntrica de Baló, que tienen buena respuesta a la terapia con glucocorticoides y donde se logra la recuperación funcional.

  11. Implementación de un balastro electrónico con microcontrolador PIC para lámparas de sodio de alta presión Implementation of electronic ballast with PIC microcontroller for high pressure sodiumlamps

    Directory of Open Access Journals (Sweden)

    Armando Manuel Gutiérrez Menéndez

    2013-09-01

    Full Text Available En el presente trabajo se muestra un prototipo de balasto electrónico, que garantiza la operación exitosa en alta frecuencia de una lámpara de sodio de alta presión de 70 W, pues opera libre de resonancia acústica (RA. Se efectúa un análisis del fenómeno de la resonancia acústica, profundizando en su origen y predicción teórica. Es descrita la técnica de modulación en frecuencia utilizada para evitar este fenómeno, implementada en el microcontrolador de 8 bit PIC16F877 de la Microchip, la cual es activada en dependencia de la variación de los parámetros eléctricos de la lámpara, como son tensión y corriente. Son mostradas las etapas que dan conformación a dicho prototipo, además de presentarse las simulaciones realizadas a los principales elementos que componen el balasto. Los resultados prácticos alcanzados por el prototipo son expuestos, los cuales se dividen por etapas para analizar el correcto funcionamiento de cada una ellas.Palabra clave: In the present work is offered a prototype of electronic ballast that guarantees the correctly operation in high frequency of a high pressure sodium lamp of 70 W, because it operates free of acoustic resonance (RA. An analysis of the phenomenon of the acoustic resonance is made, deepening in its origin and theoretical prediction. The modulation technique is described in frequency used to avoid this phenomenon, implemented in the microcontrolador of 8 bit PIC16F877 of Microchip, which is activated in dependence of the variation of the electric parameters of the lamp, like they are tension and current. They are shown the stages that give conformation to this prototype, besides the simulations carried out to the main elements that compose the ballast being presented. The practical results reached by the prototype are exposed, which are divided by stages to analyze the correct operation of each a them.Key words:

  12. Implementación de un balastro electrónico con microcontrolador PIC para lámparas de sodio de alta presión; Implementation of electronic ballast with PIC microcontroller for high pressure sodiumlamps

    Directory of Open Access Journals (Sweden)

    Armando M. - Gutiérrez Menéndez

    2013-10-01

    Full Text Available En el presente trabajo se muestra un prototipo de balasto electrónico, que garantiza la operación exitosa en alta frecuencia de una lámpara de sodio de alta presión de 70 W, pues opera libre de resonancia acústica (RA. Se efectúa un análisis del fenómeno de la resonancia acústica, profundizando en su origen y predicción teórica. Es descrita la técnica de modulación en frecuencia utilizada para evitar este fenómeno, implementada en el microcontrolador de 8 bit PIC16F877 de la Microchip, la cual es activada en dependencia de la variación de los parámetros eléctricos de la lámpara, como son tensión y corriente. Son mostradas las etapas que dan conformación a dicho prototipo, además de presentarse las simulaciones realizadas a los principales elementos que componen el balasto. Los resultados prácticos alcanzados por el prototipo son expuestos, los cuales se dividen por etapas para analizar el correcto funcionamiento de cada una ellas.In the present work is offered a prototype of electronic ballast that guarantees the correctly operation in high frequency of a high pressure sodium lamp of 70 W, because it operates free of acoustic resonance (RA. An analysis of the phenomenon of the acoustic resonance is made, deepening in its origin and theoretical prediction. The modulation technique is described in frequency used to avoid this phenomenon, implemented in the microcontrolador of 8 bit PIC16F877 of Microchip, which is activated in dependence of the variation of the electric parameters of the lamp, like they are tension and current. They are shown the stages that give conformation to this prototype, besides the simulations carried out to the main elements that compose the ballast being presented. The practical results reached by the prototype are exposed, which are divided by stages to analyze the correct operation of each a them.

  13. Consideraciones sobre el diagnóstico por imágenes de las masas selares Reflection on imaging diagnosis of sellar masses

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    José Arturo Hernández Yero

    2005-12-01

    Full Text Available Con el propósito de hacer un llamado de atención sobre una temática de importancia y tomando en consideración que con los avances en la imagenología moderna se aportan elementos distintivos y de gran utilidad en el diagnóstico por imágenes de un grupo de masas en la región de la silla turca, se hacen determinadas valoraciones al respecto, con precisión de algunas de las características de las principales masas selares y su apariencia en la resonancia magnética nuclear. Se destacan detalles en cuanto a la intensidad de la señal en los adenomas pituitarios, craneofaringiomas, quistes de la bolsa de Rathke, hiperplasia hipofisaria y el denominado síndrome de la silla turca vacía, entre otras causas de cambios anatómicos en la región selar. Se concluye que la imagen por resonancia magnética nuclear sería el método idóneo para un mejor diagnóstico de las masas selares aunque, en ausencia de esta, la tomografía contrastada puede resultar de utilidad si se realiza con cortes menores de 2 mm. Se resalta la importancia de integrar un equipo multidisciplinario entre clínicos, endocrinólogos, imagenólogos, neurocirujanos y anatomopatólogos, para obtener diagnósticos más precisos y resultados terapéuticos adecuados.Some reflections were made on imaging diagnosis of sellar masses, specifying some characteristics of the main sellar masses and their appearance in magnetic resonance imaging. The purpose was to call the attention on this important issue on the basis that modern imaging advances offer very useful distinctive elements in the diagnosis of a group of masses located in the sella turcica region. The paper underlined details of signal intensity in pituitary adenomas, craniopharyngiomas, Rathke´s pouch cysts, hypophysial hyperplasia and the so-called empty sella syndrome, among other causes of anatomical changes in sellar region. It was concluded that magnetic resonance imaging would be the ideal method for a better

  14. La bellezza aurea. Risposta cerebrale alle sculture classiche e rinascimentali

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    Cinzia Di Dio

    2010-12-01

    Full Text Available Esiste una base biologica oggettiva nell’esperienza del bello nell’arte? Oppure, l’esperienza estetica è interamente soggettiva? Usando la tecnica della risonanza magnetica funzionale, abbiamo affrontato questa domanda presentando a degli osservatori naïve allo studio dell’arte immagini di capolavori di sculture Classiche e Rinascimentali. Utilizzando la proporzione come variabile indipendente, abbiamo creato due gruppi di stimoli: uno composto da immagini di sculture originali; l’altro, da una versione modificata delle stesse immagini. Gli stimoli sono stati presentati in tre condizioni: osservazione, giudizio estetico e giudizio di proporzione. Nella condizione di osservazione, i volontari dovevano osservare le immagini con lo stesso stato mentale che avrebbero avuto se fossero stati in un museo. Nelle altre due condizioni, i volontari dovevano dare un giudizio estetico e di proporzione delle stesse immagini. Sono stati eseguiti due tipi di analisi: uno, che ha contrastato le risposte cerebrali alle sculture canoniche e modificate; ed uno, che messo a contrasto le sculture “esteticamente piacevoli” e quelle “esteticamente non piacevoli”, secondo il giudizio espresso in modo esplicito da ciascun volontario. Il risultato più interessante ha evidenziato, durante l’osservazione delle sculture originali, rispetto a quelle modificate, l’attivazione dell’insula destra e di alcune aree corticali laterali e mediali (il giro occipitale laterale, il precuneo e aree prefrontali. L’attivazione dell’insula era particolarmente evidente durante la condizione di osservazione. Inoltre, si è osservato che, quando i volontari dovevano dare un giudizio estetico esplicito, le immagini giudicate esteticamente piacevoli attivavano selettivamente l’amigdala destra rispetto a quelle giudicate esteticamente non piacevoli. Dati i risultati, abbiamo concluso che, negli osservatori naïve, il senso del bello è mediato da due processi non

  15. Electromagnetic modeling of the rings of the squirrel cage of an induction motor; Modelado electromagnetico de los anillos de la jaula de ardilla de un motor de induccion

    Energy Technology Data Exchange (ETDEWEB)

    Limones Montoya, Juan Carlos

    2004-03-15

    An electromagnetic lineal model of a three-phase induction motor was developed in this thesis. The Finite element method in two dimensions was used. The model formulation takes into account the coupling with the stator wires and solid conductors of the rotor. In other words, the stator phases and squirrel-cage end-rings are considered in the model. The resulting set of electric-circuit and magnetic-field equations are solved simultaneously with the Incomplete Cholesky Bi-Conjugate Gradient Method using a matrix storage technique known as symmetric coordinate storage. The model was programmed in the C programming language. The magnetic field model is represented by the diffusion equation, which allows to compute the induced Eddy currents in the conducting material due to the sinusoidal stator excitation. The modelled induction motor has a rated power of 2.2 kW, 220 V, 9.6/11.0 A, 60 Hz and it can be operated at the speeds of 1750/1150 rpm. It is located in the Laboratorio de Propulsion at the Instituto Tecnologico de la Laguna. [Spanish] En este trabajo de tesis se desarrollo un modelo electromagnetico lineal de un motor de induccion trifasico utilizando el Metodo de Elemento Finito en dos dimensiones, en el cual se incluye la formulacion de sistemas acoplados para los conductores delgados y gruesos presentes en el estator y rotor respectivamente. Es decir, se incluyen en el modelo las fases de alimentacion y los anillos de cortocircuito del rotor de jaula de ardilla. Las ecuaciones electricas y magneticas derivadas del modelo se resuelven de manera acoplada con el Metodo del Gradiente BiConjugado con Precondicionamiento de Cholesky Incompleto empleando el sistema de Empaquetamiento de Coordenadas, cuyo codigo se desarrollo en el lenguaje de programacion C. En este modelo se resuelve la ecuacion de difusion, mediante la cual se determinan las corrientes de Eddy que se inducen en el material conductor debido a la presencia de fuentes de alimentacion senoidales. El

  16. Quiñónez Páez, Julio (Ed.. Crisis de la modernidad, emancipación y alienación. Colección Gerardo Molina, No. 24. Bogotá: Universidad Nacional de Colombia, Facultad de Derecho, Ciencias Políticas y Sociales, Instituto Unidad de Investigaciones Jur

    Directory of Open Access Journals (Sweden)

    Rocío Rubio Serrano

    2014-01-01

    Full Text Available Crisis de la modernidad, emancipación y alienación cuestiona a través de cinco textos la creencia de una subjetividad constitutiva atrapada en la lógica de una mera libertad negativa propia de la modernidad ilustra- da, caracterizada por la irrupción de una economía capitalista, el Esta- do-nación y la apuesta por la ciencia experimental. Una modernidad en crisis que, como lo señala el prefacio, será su hilo conductor. En efecto, la promesa emancipadora y pacificadora de la modernidad está en filo y lo que se devela son procesos de alienación mediante sofisticados dis- positivos de subjetivación como los jurídicos y figuras como el estado de excepción, anclaje de la soberanía contemporánea. La felicidad sensual se nos presenta en el libro como una aspiración y escenario de emanci- pación con sutiles resonancias en la propuesta de un ser cual sea y en la de la comunidad que viene. En estas tensiones entre modernidad, eman- cipación y alienación, el lenguaje, sus tamices, movimientos, horizonte abierto, adquiere relevancia conceptual y metodológica en aras de un sentido nómada.

  17. Photooxidation of anthracene under visible light with metallocarboxyphenylporphyrins

    Directory of Open Access Journals (Sweden)

    Carlos Enrique Díaz-Uribe

    2014-01-01

    Full Text Available En este trabajo sintetizamos metalocarboxifenilporfirinas (TcPP-M, M= Cu y Zn y la carboxifenilporfirina libre de metal (TcPPH y determinamos su eficiencia en la fotooxidación de antraceno bajo luz visible a través de la generación de oxígeno singulete ( 1 O 2 . La presencia de 1 O 2 fue evidenciada por Resonancia Paramagnética Electrónica (RPE, el cual el oxígeno singulete reacciona con la 2,2,6,6-tetrametil-4-piperidona-N (TEMP para producir el radical 2,2,6,6-tetrametil-4-piperidona-N-oxil (TEMPO. Los resultados catalíticos indican que la incorporación del metal en el anillo de la porfirina afecta su eficiencia sobre la oxidación del antraceno. La TcPPH mostró la eficiencia fotónica más alta en la conversión de antraceno (31 % en comparación con la TcPPZn (13 % y TcPPCu (9 %. Estos resultados pueden ser relacionados a la distorsión de la planaridad del anillo de porfirina. Finalmente se detectó la formación de antraquinona y oxoantrona como productos de oxidación in la reacción del antraceno con 1 O 2.

  18. El esperpento en el cine de Álex de la Iglesia.

    Directory of Open Access Journals (Sweden)

    Marta RIVERO FRANCO

    2015-06-01

    Full Text Available Varios son los estudios que aluden a la presencia del esperpento en el cine de Álex de la Iglesia —tema ligado taxativamente a su producción y sin el que esta no puede entenderse—, pero escasos los que profundizan en la manera en la que este recurso se ve plasmado en sus creaciones. Por ello, con el presente trabajo, nos disponemos a analizar la forma en la que el esperpento se manifiesta en su filmografía, para lo que seleccionaremos tres de sus ficciones esenciales —El día de la bestia (1995, La comunidad (2000 y Balada triste de trompeta (2010—, a través de las que comprobaremos cómo la intertextualidad, la crítica social y esa mezcla de cultura posmoderna con resonancias de la España más atávica, son las características que constituyen la esencia de tan idiosincrático recurso dentro de su producción.

  19. Formación y estructura secundaria del 2,3 -bis-(3,4 -dimetoxibenzoíl propionitrilo

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    Francisco Sánchez Viesca

    2004-01-01

    Full Text Available El 3,4-dimetoxibenzoílacetonitrilo y el 2,4,5-trimetoxibenzoílacetonitrilo, requeridos en la síntesis de derivados isoxazólicos, se obtuvieron a partir de las α-halocetonas, la α-bromoacetoveratrona y el cloruro de 2,4,5-trimetoxifenacilo. En el primer caso se aisló un subproducto inesperado cuya estructura se dedujo de su espectroscopía (IR, RMN de 1H y EM y de su análisis elemental cuantitativo. Se identificó como 2,3-bis-(3,4-dimetoxibenzoílpropionitrilo. Del estudio cuidadoso de su espectro de resonancia magnética protónica se dedujo la existencia de 2 puentes de hidrógeno débiles, intramoleculares, del tipo C−H---O=C, debido a los desplazamientos químicos a mayor frecuencia que presentan los hidrógenos involucrados en dichas interacciones, así como, variaciones significativas en las constantes de acoplamiento de estos hidrógenos. Se observaron corrimientos, ∆δ, de 0.5 y de 1 ppm, como se discute en el texto. Esto se confirmó con modelos moleculares y mediante un estudio teórico empleando la teoría de funcionales de la densidad.

  20. Hemorragia del postparto. Principales etiologías, su prevención, diagnóstico y tratamiento

    Directory of Open Access Journals (Sweden)

    DR. A. Aldo Solari

    2014-11-01

    Full Text Available La hemorragia del postparto es una de las principales emergencias obstétricas. La tasa de mortalidad materna por hemorragias oscila entre 30 y 50%. Los factores de riesgo más importantes son: edad materna avanzada y enfermedades crónicas. La etiología más frecuente es la Inercia Uterina, definida como la incapacidad del útero de retraerse luego del alumbramiento. Su prevención se basa en el manejo activo del trabajo de parto y el tratamiento va desde el uso de terapias farmacológicas con uterotónicos hasta la histerectomía de urgencia. El Acretismo es una inserción anormal de la placenta. Su diagnóstico se basa en el uso de Ecografía y Resonancia Nuclear Magnética y su tratamiento es el parto por cesárea con histerectomía. La radiología intervencionista ha contribuido a disminuir de forma importante la severidad de la hemorragia postparto. Es imprescindible contar con guías de acción protocolizadas para así evitar o disminuir su incidencia y magnitud.

  1. ¿Es posible objetivar el dolor?

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    DR. S. Mario Campero

    2014-07-01

    Full Text Available El dolor es una experiencia cognitiva como resultado de la activación de nociceptores o descritas en esos términos. El estímulo nociceptivo desencadena la activación de redes neuronales que procesan la información en forma paralela y distribuida, con un componente discriminativo en el tálamo y corteza primaria contra lateral y otro afectivo en la corteza del cíngulo anterior y prefrontal dorsolateral. El dolor como experiencia psíquica solo puede ser objetivado en sus aspectos de activación de las áreas de la así llamada matriz de dolor, mediante la técnica de resonancia magnética funcional. Con el registro de la actividad de nociceptores en sujetos despiertos y en pacientes con dolor neuropático mediante microneurografía se puede relacionar la actividad anormal en estos receptores con la sensación evocada.

  2. Susac syndrome: the first case report in Peru

    Directory of Open Access Journals (Sweden)

    Carolina Rivadeneira-Sotelo

    2017-08-01

    Full Text Available Resumen El síndrome de Susac es una entidad rara, caracterizada por la triada clásica de encefalopatía subaguda, oclusión de la arteria retiniana e hipoacusia neurosensorial. Es más frecuente en mujeres, la edad de inicio fluctúa entre los nueve y los 58 años de edad. La patogénesis se plantea como un cuadro microangiopático a nivel cerebral, retiniano y coclear asociado a un mecanismo autoinmune. Presentamos el caso de una mujer de 31 años de edad que inició con cefalea holocraneana, conducta pueril, bradilalia y somnolencia. En la angiografía con fluoresceína de retina presentó en la evolución un déficit auditivo y obstrucción arterial de la rama temporal retiniana derecha. La resonancia magnética cerebral mostró lesiones redondeadas hiperintensas en el cuerpo calloso, región periventricular y cerebelo. Se reporta el primer caso de síndrome de Susac definido en Perú, el que se manifestó con la triada clásica, que es de presentación poco frecuente. Sin embargo, también los casos que muestran formas incompletas deben ser evaluados oportunamente para iniciar un tratamiento oportuno y evitar secuelas irreversibles.

  3. Biografía de la Facultad de Derecho de la Universidad Simón Bolívar: Testimonio de un esfuerzo

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    Maury Almanza Iglesia

    2015-10-01

    Full Text Available Cuando se habla de universidad, lo primero que viene a la mente es el concepto de academia por haber sido el primer lugar que formalmente se conoció como sinónimo de formación. Alude también a espacios de ecos y resonancias en donde todo se movía entre la mesura y el regodeo, entre la lentitud y la paciencia y por la libertad, la tranquilidad y el saber como presupuestos básicos. Por tal razón se da cuenta del estudio biográfico de la Facultad de Derecho de la Universidad Simón Bolívar, Barranquilla-Colombia.AbstractWhen it is talked about university the first thing that comes to a mind is the concept of academy because it was the first place formally known like a higher education school. It refers to spaces full of echoes and resonances where everything was moving between moderation and gloating, between slowness and patience, and that is moving for the liberty, tranquility and knowledge. It is the main reason of the biographical study of the Simon Bolivar University’s law faculty in Barranquilla, Colombia.

  4. Mielopatía transversa asociada a embolismo de tejido fibrocartilaginoso: Presentación clínico-patológica de un caso Transverse myelopathy associated with embolism of fibrocartilaginous tissue: A clinicopathologic case report

    Directory of Open Access Journals (Sweden)

    Alma Torres Gómez de Cádiz

    2006-09-01

    Full Text Available Se presenta el caso clínico-patológico de un adolescente con cuadriplejía de comienzo brusco y pérdida de esfínteres, sin historia de trauma y solo con el antecedente de un proceso respiratorio alto de carácter banal. La resonancia magnética demostró una extensa cavidad siringomiélica en la médula cervical espinal. El paciente tuvo una evolución séptica tórpida y falleció a los 62 días de su ingreso. La autopsia reveló una cavidad quística en médula cervical como secuela de infartos isquémicos producidos por émbolos fibrocartilaginosos en vasos arteriales y venosos. Los émbolos fibrocartilaginosos como causa de mielitis o mejor denominada mielopatía transversa, sobre todo en adolescentes, han sido descritos por otros autores y se ha subrayado el comienzo brusco de la parálisis en el curso de este proceso vascular obstructivo.

  5. De lo con-céntrico a lo des-centrado. Reflexiones sobre el lugar y el no-lugar en la arquitectura. / From the concentric to the off-center. Reflections on the place and the non-place in architecture.

    Directory of Open Access Journals (Sweden)

    Laura Gallardo Frías

    2012-06-01

    Full Text Available Se propone, a través de la figura del círculo, abrir una reflexión sobre sus propiedades, su presencia y permanencia lo largo de la historia así como en nuestros días. Se invita al lector a un paseo por diferentes propuestas arquitectónicas y pensamientos paraexplorar el paso de lo con-céntrico a lo des-centrado, revisando las nociones de lugar, no-lugar y sus relaciones con la arquitectura. Poniendo de relieve la importancia del proyecto arquitectónico capaz de conformar centros donde el ser humano sea uno consigo mismo y loque le rodea, produciendo una profunda resonancia./ It is proposed, through the figure of the circle, opening a reflection on their properties, their presence and permanence throughout history and today. It invites the reader on a tour of different architectural proposals and thoughts to explore the transition from the con-centric to the ec-centric, reviewing the notions of place, non-place andits relationship with architecture. Emphasizing the importance of architecture as capable of forming centers where a human being with himself and his surroundings to produce a deep resonance.

  6. INTERVALOS DE INTEGRACIÓN UNIFICADOS PARA LA CARACTERIZACIÓN ESTRUCTURAL DE PETRÓLEOS, CARBONES O SUS FRACCIONES POR RMN 1H Y RMN 13C

    Directory of Open Access Journals (Sweden)

    Avella Eliseo

    2010-09-01

    Full Text Available Con base en la revisión de publicaciones, hechas entre 1972 y 2006, se evidenció que hay imprecisiones en los límites de los intervalos de integración que los autores asignan a las señales en resonancia magnética nuclear (RMN para hacer la caracterización estructural de petróleos, carbones o sus fracciones derivadas, a partir de sus espectros de hidrógeno (RMN 1H o de carbono (RMN 13C. En consecuencia, se determinaron límites unificados para la integración de los espectros RMN 1H y RMN 13C de tales muestras mediante un tratamiento estadístico aplicado a los límites de los intervalos de integración ya publicados. Con esos límites unificados se elaboraron cartas de correlación en RMN útiles para la asignación de la integral en esos intervalos, y aun en otros de menor extensión definidos en función de la intersección entre asignaciones diferentes. Además se plantearon ecuaciones necesarias para establecer la integral atribuible a fragmentos más específicos en un intento por hacer una caracterización estructural más exacta a partir de los espectros RMN de petróleos, carbones o sus fracciones derivadas.

  7. BIOTRANSFORMACIÓN DE LOS SUSTRATOS 2-FENILETANOL Y ACETOFENONA CON EL HONGO FITOPATÓGENO Colletotrichum acutatum

    Directory of Open Access Journals (Sweden)

    Diego Aristizábal

    2009-03-01

    Full Text Available En este estudio se evaluaron las biotransformaciones realizadas por el hongo fitopatógeno Colletotrichum acutatum, sobre los sustratos 2-feniletanol 1 y acetofenona 2; los procesos se realizaron en el medio de cultivo líquido Czapeck-Dox a temperatura promedio de 24 oC, humedad relativa entre 45 % y 60 % y agitación a 150 rpm en un agitador orbital tipo shaker.  En la biotransformación a partir del sustrato 1 se obtuvieron los productos metabólicos 1-fenil-1,2-etanodiol 3, (2-metoxietilbenceno 4 y acetato de 2-feniletilo 5, y desde el sustrato 2 los compuestos 1-fenil-1,2-etanodiol 3, 1-feniletanol 6 y 2-feniletanol 1.  Los productos de la transformación microbiana se identificaron mediante cromatografía de gases acoplada a espectrometría de masas (CG-EM y resonancia magnética nuclear de protón y carbono (RMN 1H y 13C. Se observó una tendencia marcada del patógeno a producir hidroxilaciones sobre el sustituyente del anillo aromático; igualmente tiene la capacidad de reducir el grupo carbonilo y esterificar los grupos hidroxilo de alcoholes primarios.  Se discute una posible ruta metabólica para la transformación de los sustratos.

  8. La presencia de PISA en la literatura científica y su tratamiento en la prensa diaria internacional

    Directory of Open Access Journals (Sweden)

    Antonio Luzón

    2013-01-01

    Full Text Available Este artículo examina y analiza la producción científica tanto en la literatura científica, como el uso público que se ha realizado del Programa para la Evaluación Internacional de los Estudiantes (PISA desarrollado por la OCDE. En concreto, comprueba qué influencia ha tenido PISA en la literatura científica desde su creación y ello se verifica a través de las publicaciones halladas a través de la Web of Science (WoS de Thomson-Scientific, que incluye diversas bases de datos: Science Citation Index (SCI, Social Sciences Citation Index (SSCI y Arts & Humanities Citation Index, (AHCI de Thomson Reuters así como en Scopus de Elsevier. También incide sobre la presencia de PISA en los cada vez más utilizados motores de búsqueda de cuarta generación como Google Scholar, de carácter abierto y gratuito. Al mismo tiempo, pretende comprobar la resonancia que tiene en la prensa diaria y su impacto mediático mundial que ha originado la publicación del último informe PISA (2009 en los principales diarios españoles e internacionales.

  9. Ludopatía y epilepsia en demencia frontotemporal: Reporte de dos casos

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    Sheila Castro-Suarez

    Full Text Available RESUMEN La demencia frontotemporal es un trastorno neurodegenerativo cuyo subtipo más común es la variante conductual. Es considerada la causa de demencia más frecuente en menores de 60 años. Se presentan dos casos no emparentados cuyos síntomas típicos fueron: deterioro progresivo de la cognición, del comportamiento, alteraciones psiquiátricas como desinhibición, actos impulsivos, apatía, falta de empatía, estereotipias y cambios en los hábitos de alimentación. La resonancia magnética cerebral, en ambos casos, mostró atrofia frontotemporal a predominio izquierdo; en la evaluación neuropsicológica se evidenció alteraciones de las funciones ejecutivas. El primer caso cursó con ludopatía como síntoma inicial, motivo por el cual permaneció por un año en un centro psiquiátrico, siendo el segundo en Latinoamérica y uno de los pocos casos reportados en el mundo. El segundo caso presentó crisis epilépticas en su evolución.

  10. Muerte súbita por conmoción cardíaca (Commotio cordis asociada a miocardio no compactado

    Directory of Open Access Journals (Sweden)

    Analía Aquieri

    2011-12-01

    Full Text Available El miocardio no compactado es una rara miocardiopatía congénita caracterizada por la presencia de múltiples y prominentes trabeculaciones profundas en la pared ventricular que definen hendiduras comunicantes con el compartimiento ventricular principal. Es una entidad de baja incidencia y prevalencia que se diagnostica mediante estudios de imágenes como el ecocardiograma Doppler (ED, la tomografía computarizada multicorte (TCM y la resonancia magnética cardíaca (RMC. Puede ser asintomática o manifestarse mediante arritmias, insuficiencia cardíaca o eventos tromboembólicos. Se presenta el caso de un hombre de 33 años, asintomático, que durante la práctica deportiva sufre una conmoción cardíaca (commotio cordis que le produce un paro cardiorrespiratorio. El electrocardiograma mostró un ritmo de aleteo ventricular que requirió cardiodesfibrilación eléctrica. En un ED efectuado inicialmente no se observaron anormalidades significativas, pero otro ED, una TCM y una RMN obtenidos luego del alta, certificaron el hallazgo de miocardio no compactado aislado, descartando coronariopatía. Recibió tratamiento beta bloqueante y antiagregante y se discutió la colocación del cardiodesfibrilador implantable. Se plantea la fisiopatología de la asociación de estas dos infrecuentes y potencialmente letales afecciones.

  11. Presentación. Género, cuerpo y sexualidad. Cultura y ¿Naturaleza?

    Directory of Open Access Journals (Sweden)

    AIBR. Consejo de Redacción

    2006-01-01

    Full Text Available En 1974, se recogió en un libro editado por Michelle Zimbalist Rosaldo y Louise Lamphere, las ponencias sobre género que habían sido presentadas en una mesa sobre “mujeres, hombres, cultura y sociedad” en el Congreso de la American Anthropological Association de 1972, celebrado en Toronto. De ellas, las tres primeras tuvieron una gran resonancia por su intento de explicar el universal de la dominación masculina. Michelle Rosaldo (1974 planteaba un modelo estructural que aunaba aspectos de la psicología, la organización social y cultural relacionándolos con la oposición entre lo público y lo privado. Sherry Ortner (1974, con una orientación influenciada por el estructuralismo de Lévi-Strauss, estudiaba los paralelismos entre las dicotomías hombre / mujer y naturaleza / cultura; mientras Nancy Chodorow (1974 se centraba en las relaciones y estructura familiar desde una perspectiva más psicológica con influencia de los planteamientos freudianos.

  12. Varón de 48 años con diarrea y colestasis

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    A. Jímenez Jurado

    2015-09-01

    Full Text Available Presentamos el caso de un varón de 48 años derivado a la consulta por un cuadro clínico de diarrea crónica (> 6 semanas junto con alteración de las pruebas de función hepática consistente en un patrón de colestasis. La presencia de diarrea crónica y colestasis nos obligaron al diagnóstico diferencial entre las siguientes entidades: enfermedad celíaca, enferme-dad inflamatoria intestinal, enfermedades infecciosas crónicas (tuber-culosis intestinal, micobacterium avium en inmunodeprimidos, causas metabólicas como la amiloidosis, obstrucción de la vía biliar intrahepatica (ductopenia del adulto, colangitis esclerosante primaria o secundaria, toma de fármacos y finalmente causas tumorales (colangiocarcinoma, linfoma de Hodgkin, adenocarcinoma colon. En el caso que presentamos, la colangio resonancia magnética nuclear fue la herramienta diagnóstica fundamental para el diagnóstico de la entidad

  13. Active vibration control of a rotor-bearing system based on dynamic stiffness

    Directory of Open Access Journals (Sweden)

    Andrés Blanco Ortega

    2010-01-01

    Full Text Available En este artículo se presenta un esquema de control activo de vibraciones para atenuar las amplitudes de vibración síncrona inducidas por el desbalance en un sistema rotorchumaceras; donde una de las chumaceras puede ser desplazada automáticamente para modificar la longitud efectiva del rotor, y como consecuencia, la rigidez del rotor. El control de la rigidez dinámica se basa en un análisis de la respuesta en frecuencia, control de velocidad y en el uso de esquemas de aceleración, para evadir las amplitudes de la vibración en la resonancia mientras el sistema rotatorio pasa (acelerado o desacelerado a través de una velocidad crítica. Se utiliza identificación algebraica para estimar el desbalance en línea, mientras el rotor es llevado a la velocidad de operación deseada. Algunas simulaciones numéricas y resultados experimentales son incluidos para mostrar las propiedades de la compensación del desbalance y la robustez del esquema de control activo de vibraciones propuesto, cuando el rotor se opera a una velocidad por encima de la primera velocidad crítica.

  14. Miocárdio não compactado, Doença de Chagas e disfunção: relato de caso Miocardio no compactado, Enfermedad de Chagas y disfunción: caso clínico Noncompaction of the myocardium, Chagas' disease and dysfunction: a case report

    Directory of Open Access Journals (Sweden)

    Ronaldo Peixoto de Mello

    2010-07-01

    Full Text Available Relatamos a associação entre a cardiopatia associada ao miocárdio não compactado do ventrículo esquerdo (MNCVE à cardiopatia chagásica crônica (CCC em paciente com clínica de insuficiência cardíaca, acidente vascular cerebral isquêmico e arritmia cardíaca. As imagens típicas de MNCVE e CCC foram documentadas pela ressonância magnética cardíaca (RMC.Relatamos la asociación entre la cardiopatía asociada al miocardio no compactado del ventrículo izquierdo (MNCVI con la cardiopatía chagásica crónica (CCC en paciente con clínica de insuficiencia cardíaca, accidente vascular cerebral isquémico y arritmia cardíaca. Las imágenes típicas de MNCVI y CCC fueron documentadas por resonancia magnética cardíaca (RMC.We report the association between heart disease associated with noncompaction of the left ventricular myocardium (NCLVM and chronic Chagas' heart disease (CCHD in a patient with heart failure, ischemic stroke and cardiac arrhythmia. Images typical of NCLVM and CCHD were documented by cardiac magnetic resonance imaging (CMRI.

  15. MODIFICACIONES DE LAS PROPIEDADES TEXTURALES Y ESTRUCTURALES DE UNA ZEOLITA USY Y DE SUS MEZCLAS CON "CAOLÍN CLAY" Y CLORHIDROL COMO CONSECUENCIA DEL TRATAMIENTO HIDROTÉRMICO

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    Yazmin Yaneth Agamez Pertuz

    2008-03-01

    Full Text Available El catalizador de FCC está constituido por partículas de composición compleja donde el componente activo es una zeolita Y. En este trabajo se presentan los resultados texturales y estructurales de una zeolita USY comercial lixiviada, de una serie de catalizadores con 7, 15, 25, 35 y 45% de material activo y los de estos materiales desactivados hidrotérmicamente. Las muestras se caracterizaron por fluorescencia de rayos X (FRX, difracción de rayos X (DRX, resonancia magnética nuclear de silicio (29Si RMN y fisiadsorción de nitrógeno a 77 K. A partir de estos resultados se hallaron correlaciones entre el volumen de microporo y el contenido de zeolita y entre el grado de cristalinidad y el porcentaje de zeolita. Además, se encontró que un tratamiento con sólo 20% de vapor de agua a 1033 K durante 16 horas destruye los grupos estructurales Si(2Al y Si(3Al como reflejo de la dealuminización drástica que sufre el material. 

  16. PFI-ZEKE (Pulsed Field Ionization-Zero Electron Kinetic Energy) para el estudio de iones

    Science.gov (United States)

    Castaño, F.; Fernández, J. A.; Basterretxea, A. Longarte. F.; Sánchez Rayo, M. N.; Martínez, R.

    Entre las áreas hacia donde ha evolucionado la Química en los últimos años están los estudios de sistemas con especies reactivas de alta energía y los dominados por fuerzas intermoleculares débiles, con energías de unas pocas kcal/mol. En efecto, el estudio de las propiedades de los iones, comenzando por su relación con la molécula neutra de la que procede, la energía de ionización, los estados vibracionales y rotacionales, energías de enlace de Van der Waals entre el ión y una amplia variedad de otras moléculas, sus confórmeros o isómeros y sus reacciones o semi-reacciones químicas están en la raíz de la necesidad de la espectroscopía conocida como PFI-ZEKE, Pulsed Field Ionization-Zero Electron Kinetic Energy. Entre las aplicaciones que requieren estos conocimientos se encuentran la generación de plasmas para la fabricación de semiconductores, memorias magnéticas, etc, así como los sistemas astrofísicos, la ionosfera terrestre, etc. La espectroscopía ZEKE es una evolución de las de fluorescencia inducida por láser, LIF, ionización multifotónica acrecentada por resonancia, REMPI, con uno y dos colores y acoplada a un sistema de tiempo de vuelo, REMPI-TOF-MS, y las espectroscopías de doble resonancia IR-UV y UV-UV. Sus espectros y la ayuda de cálculos ab inicio permite determinar las energías de enlace de complejos de van der Waals en estados fundamental y excitados, identificar confórmeros e isómeros, obtener energías de ionización experimentales aproximadas (100 cm-1) y otras variables de interés. Al igual que con LIF, REMPI y dobles resonancias, es posible utilizar muestras gaseosas, pero los espectros están muy saturados de bandas y su interpretación es difícil o imposible. Se evitan estas dificultades estudiando las moléculas o complejos en expansiones supersónicas, donde la T de los grados de libertad solo alcanzan unos pocos K. Para realizar experimentos de ZEKE hay que utilizar una propiedad recientemente

  17. Enfermedad de creutzfeldt-jakob en el Perú: reporte de once casos

    Directory of Open Access Journals (Sweden)

    Luis Torres-Ramírez

    Full Text Available La enfermedad de Creutzfeldt-Jakob (ECJ es una enfermedad neurológica fatal producida por la isoforma patológica de la proteína priónica humana. Se reporta las características clínicas de seis casos de la forma esporádica de ECJ con diagnóstico definitivo por histopatología, y cinco casos con diagnóstico probable, en pacientes atendidos en el Instituto Nacional de Ciencias Neurológicas del Perú. La edad de inicio en los casos definitivos fue de 55,8 años y, en los probables, de 59,6 años, con predominio del sexo masculino. El tiempo de enfermedad fue de 8,8 meses. Se encontró un EEG típico en 50% de los casos definitivos y 80% de los probables. La proteína 14-3-3 en líquido cefalorraquídeo fue positiva en un caso probable y los hallazgos típicos en resonancia magnética se observaron en dos casos probables. Todos los casos cursaron con una evolución clínica típica de la enfermedad, y se considera el primer reporte de ECJ en el Perú

  18. Narraciones compartidas: imaginarios políticos entre Charcas y Buenos Aires (de las reformas borbónicas al proceso juntista

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    Esteban De Gori

    2013-07-01

    Full Text Available Este artículo expone los vínculos entre las elites charqueñas y rioplatenses desde mediados del siglo XVIII hasta inicios del siglo XIX, con una mirada que incorpora la relación territorial y el vínculo de las culturas políticas que se entretejen en la conformación de ambas elites. El trabajo da cuenta de los vínculos políticos entre el mundo charqueo y el rioplatense, asumiendo ambas realidades como vinculadas e interdependientes; y muestra que dicho vínculo estuvo configurado por narraciones y preocupaciones comunes, el impacto de la crisis imperial, la resonancia de la insurgencia indígena en los años previos (La Gran Rebelión de los Andes y la Rebelión Túpac Katari y las experiencias autonomistas del mundo andino: La Plata (Chuquisaca y La Paz. Se utilizan los aportes de la historia conceptual y la sociología política para analizar esos complejos mundos políticos y de conformación de las elites.

  19. Narraciones compartidas: imaginarios políticos entre Charcas y Buenos Aires (de las reformas borbónicas al proceso juntista

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    Esteban de Gori

    2013-07-01

    Full Text Available Este artículo expone los vínculos entre las élites charqueñas y rioplatenses desde mediados del siglo XVIII hasta inicios del siglo XIX, con una mirada que incorpora la relación territorial y el vínculo de las culturas políticas que se entretejen en la conformación de ambas élites. El trabajo da cuenta de los vínculos políticos entre el mundo charqueño y el rioplatense, asumiendo ambas realidades como vinculadas e interdependientes; y muestra que dicho vínculo estuvo configurado por narraciones y preocupaciones comunes, el impacto de la crisis imperial de 1808, la resonancia de la insurgencia indígena en los años previos (La Gran Regelión de los Andes y la Rebelión de Túpac Katari y las experiencias autonomistas del mundo andino: La Plata (Chiquisaca y La Paz. Se utilizan los aportes de la historia conceptual y la sociología política para analizar esos complejos mundos políticos y de conformación de élites.

  20. Amphoteric surface active agents

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    Eissa, A.M. F.

    1995-10-01

    Full Text Available 2-[trimethyl ammonium, triethyl ammonium, pyridinium and 2-amino pyridinium] alkanoates, four series of surface active agents containing carbon chain C12, C14, C16 and C18carbon atoms, were prepared. Their structures were characterized by microanalysis, infrared (IR and nuclear magnetic resonance (NMR. Surface and interfacial tension, Krafft point, wetting time, emulsification power, foaming height and critical micelle concentration (cmc were determined and a comparative study was made between their chemical structure and surface active properties. Antimicrobial activity of these surfactants was also determined.

    Se prepararon cuatro series de agentes tensioactivos del tipo 2-[trimetil amonio, trietil amonio, piridinio y 2-amino piridinio] alcanoatos, que contienen cadenas carbonadas con C12, C14, C16 y C18 átomos de carbono.
    Se determinaron la tensión superficial e interfacial, el punto de Krafft, el tiempo humectante, el poder de emulsionamiento, la altura espumante y la concentración critica de miscela (cmc y se hizo un estudio comparativo entre la estructura química y sus propiedades tensioactivas. Se determinó también la actividad antimicrobiana de estos tensioactivos. Estas estructuras se caracterizaron por microanálisis, infrarrojo (IR y resonancia magnética nuclear (RMN.

  1. EFECTO DEL ULTRASONIDO EN LA SÍNTESIS DE ARCILLA PILARIZADA CON ALUMINIO EN MEDIO CONCENTRADO

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    Sonia Moreno

    2009-04-01

    Full Text Available En este trabajo se realizó la síntesis de bentonita pilarizada con aluminio en medio concentrado, empleando ultrasonido en la etapa de intercalación. El agente pilarizante fue preparado por hidrólisis del AlCl3 con NaOH, seguido de precipitación con disolución de Na2SO4 y redisolución en Ba(NO32, y fue caracterizado por fluorescencia de rayos X (FRX, difracción de rayos X (DRX, microscopía electrónica de barrido (SEM y resonancia magnética nuclear de aluminio (27Al-RMN. La arcilla pilarizada fue caracterizada por FRX, DRX y fisiadsorción de N2 a 77 K, revelando propiedades estructurales y texturales comparables a la modificada siguiendo la metodología convencional: suspensiones diluidas y tiempos de intercalación elevados. El empleo de suspensiones concentradas de arcilla-agente pilarizante y la aplicación de ultrasonido en la etapa de intercalación, permiten una disminución en el volumen de agua entre el 90-95 % y una reducción en el tiempo de intercalación entre el 70–93 % respecto al método convencional de pilarización.

  2. Aporías narrativas en Lucía y el sexo de Julio Medem

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    Pascale Thibaudeau

    2011-04-01

    Full Text Available Este artículo propone un estudio de la estructura narrativa de la película Lucía y el sexo de Julio Medem a partir de algunas nociones deconstructivistas sintetizadas en la introducción. Los juegos elaborados por la instancia enunciadora alrededor de los distintos niveles internos de narración provocan regularmente un cuestionamiento de los límites entre ficción y realidad que parecían haber sido definidos anteriormente y desembocan en una forma de “indecidabilidad” narrativa.El proceso de escritura puesto en escena por la película (el protagonista es escritor justifica las innumerables vías que toma una narración que se va construyendo bajo nuestra mirada y donde todo participa en la descomposición de la linearidad del relato. Constantemente desplazado, el lugar de donde procede la narración se virtualiza, lo que favorece la multiplicación de pistas de interpretación contradictorias entre las que ninguna se revela, de por sí, satisfactoria. En permanente proceso de diseminación y de “diferancia” del sentido, esta película entra en resonancia con las aporías deconstructivistas.nacional-católicos

  3. Amphoteric surfactants containing ?-hydroxy ester group and an amino acid residue

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    Eissa, A. M. F.

    2006-09-01

    Full Text Available A series of amphoteric surfactants containing α-hydroxy ester group and an amino acid residue were prepared with the addition of epoxy derivatives (which were prepared from epoxidation of alkyl methacrylate to different types of amino acids (glycine, alanine, valine, isoleucine, phenylalanine, tyrosine, serine, threonine, aspartic and anthranilic acid.The structures of the prepared compounds were confirmed by infrared spectra, proton magnetic resonance spectra, Mass spectra and elementary analysis. Surface tension, Kraft point, foaming power, critical micelle concentration emulsion and Ca++ stabilities were determined. Antimicrobial activity and biodegradability were also screened.Se prepararon una serie de tensioactivos anfóteros conteniendo un grupo alfa hidroxi éster y un residuo de aminoácido por adición de derivados epoxy (obtenidos mediante epoxidación de metacrilato de alquilo a diferentes tipos de aminoácidos (glicina, alanina, valina, isoleucina, fenilalanina, tirosina, serina, treonina y ácidos aspártico y antranílico. Las estructuras de los compuestos preparados se confirmaron por los espectros de infrarrojo, de masa, resonancia magnética nuclear de protones y análisis elemental. Se determinaron la tensión superficial, el punto de Kraft, el poder espumante, la concentración micelar crítica en emulsión y las estabilidades de Ca++. También se estudiaron la actividad antimicrobiana y la biodegradabilidad.

  4. Obtaining a sulfoaluminate belite cement by industrial waste

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    Elkhadiri, L.

    2003-06-01

    Full Text Available Sulfoaluminate belite clinkers by burning raw at moderate temperatures near 1250 °C were synthesized. The used mixtures were made by calcium carbonate blended to two industrial wastes: low calcium fly ash and phosphogypsum. The clinkers were characterised by X-Ray Diffraction (XRD, Infrared Spectroscopy (FTIR and free lime. The hydraulic behaviour of the obtained cements, by adequate clinkers with 7% of added gypsum, was followed by XRD, scaning electronic microscopy (SEM, FTIR and NMR.

    Los clínkeres belíticos de sulfoaluminatos se obtienen por cocción de crudos a temperaturas moderadas, hacia 1.250 ºC. Esos crudos se componen de carbonato de calcio mezclados con dos subproductos industriales: cenizas volantes pobres en óxido de calcio y fosfoyeso. Los clínkeres obtenidos se caracterizaron a través de Difracción de Rayos X (DRX, Espectroscopia Infrarroja por Transformada de Fourier (FTIR y por la determinación de CaO libre. El comportamiento hidráulico de los cementos elaborados de los clínkeres con el 7% de yeso se estudió por DRX, Microscopía Electrónica de Barrido (SEM, FTIR y Resonancia Magnética Nuclear (RMN

  5. Reflexiones sobre la pertinencia de la educación en el campo de la gerontología en Colombia y en el mundo

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    Lucelly Ardila Vega

    2016-03-01

    Full Text Available Este artículo tiene como propósito presentar un cúmulo de reflexiones sobre la pertinencia de la gerontología como carrera profesional, las cuales se sustentan en un conjunto de necesidades y aspectos que tienen resonancia a diferente escala (mundial y nacional tales como: el envejecimiento demográfico y sus consecuencias; la transición epidemiológica; el perfil social de la población vieja; el reto de la dependencia; el rol de las personas mayores en la socialización de generaciones más jóvenes y, en la normatividad en temas relacionados con el envejecimiento y la vejez. Se concluye, con preocupación, que ante el panorama que justifica plenamente la necesidad de formar profesionales en gerontología, hoy exista una muy baja oferta de formación en pregrado en este campo en Colombia, lo cual demuestra la poca visibilización de las profundas transformaciones y consecuencias que, a mediano y largo plazo, trae el proceso de envejecimiento que actualmente vive el mundo y nuestro país.

  6. OBESIDAD Un problema no tan simple. [Obesity - Not such an easy problem].

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    Luis M. López-Mojares

    2015-10-01

    Full Text Available Siguiendo a los clásicos, el obeso es el nutrido en exceso. En definitiva, lo más característico del obeso es el exceso de grasa corporal, superior al 33 % en el caso de las mujeres y del 25 % en el de los varones. De tal manera que el diagnóstico más preciso se obtiene de las medidas directas de masa grasa que nos ofrece la densitometría (Direk 2013 u otras técnicas de imagen como la resonancia magnética. Sin embargo, la sencillez y difusión de la ecuación del estadístico del siglo XIX, Lamberto Quetelet, han hecho que en la actualidad, la inmensa mayoría de las instituciones públicas y privadas, encabezadas por la Organización Mundial de la Salud, admitan como referencia (OMS 2015 el Índice de Masa Corporal (IMC.

  7. Linfoma primario del sistema nervioso central en un paciente inmunocompetente

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    José Málaga-Zenteno

    2012-07-01

    Full Text Available El linfoma primario del sistema nervioso central (LPSNC constituye el 2% de los linfomas extranodales y entre 0,3% y 1,5% de todas las neoplasias intracraneales en pacientes inmunocompetentes, siendo más frecuente a partir de los 60 años. Reportamos el caso de un paciente varón de 76 años, sin antecedentes médicos de importancia, que inició su enfermedad con inestabilidad en la marcha, dificultad para mover el hemicuerpo izquierdo, a predominio braquial, cefalea holocraneal y mareos. Ingresó a emergencia despierto, parcialmente desorientado, Glasgow 14 y ptosis palpebral derecha; además, hemiparesia e hipoestesia izquierda, a predominio crural. Por tomografía computarizada cerebral se evidenció imagen captadora de contraste en región frontoparietal derecha, intra y extra craneal, edema cerebral y desplazamiento de la línea media. Se realizó craneotomía y biopsia del tumor, diagnosticándose linfoma difuso de células grandes B del sistema nervioso central. Fue VIH negativo. Se descartó otro tumor primario y metástasis. Recibió esquema CHOD/BVAM y radioterapia. Evolucionó favorablemente. Según resonancia magnética cerebral postratamiento, desapareció el tumor.

  8. Síndrome de Benedikt secundario a trauma craneoencefálico. Presentación de un caso y revisión de la literatura

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    M. Esqueda-Liquidano

    2014-07-01

    Full Text Available Presentamos el caso clínico de un niño 12 años de edad con trauma cerebral secundario a un accidente automovilístico. Ingresó al servicio de urgencias con escala de coma de Glasgow de 10 puntos, somnoliento y anisocoria con midriasis derecha. La tomografía computada y la resonancia magnética de cráneo evidenciaron la presencia de una hemorragia en el tegmento ventral mesencefálico derecho y edema cerebral difuso. Una vez mejorado su estado de alerta, la exploración neurológica reveló una parálisis del tercer nervio craneal derecho, hemiparesia leve, hiperreflexia tendinosa, signo de Babinski y temblor de intención de las extremidades izquierdas. De acuerdo con los hallazgos clínicos y radiológicos se concluye que se trataba de un síndrome de Benedikt.

  9. Falso seudoaneurisma del ventrículo izquierdo

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    Silvio Acevedo

    2007-01-01

    Full Text Available El ventrículo izquierdo puede presentar abultamientos patológicos, que se denominan aneurisma, seudoaneurisma o divertículo. Los aneurismas son los más frecuentes y su etiología más común es la enfermedad coronaria.Presentamos un paciente de 16 años, derivado al Hospital Escuela de Corrientes con diagnóstico de accidente cerebrovascular. Por eco-Doppler color, resonancia magnética y cinecoronariografía se diagnosticó seudoaneurisma ventricular izquierdo. El examen histológico demostró la presencia de fibras musculares cardíacas, por lo que se concluyó que se trataba de un aneurisma ventricular izquierdo. Esta discordancia entre el diagnóstico por imágenes y la anatomía patológica fue descripta por Mackenzie con el nombre de falso seudoaneurisma.

  10. España y Japón en el siglo XVII: las dos embajadas de la era Keichô (1596-1615

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    Carlos Martínez Shaw

    2016-10-01

    Full Text Available A principios del siglo XVII, Japón envió dos embajadas a España para entablar una negociación sobre asuntos políticos, económicos y misionales. La que debe ser llamada “primera embajada de la era Keichô” ofreció a los barcos españoles una escala segura en los puertos japoneses a cambio de abrir alguno de esos puertos al comercio con la plaza novohispana de Acapulco, pero el denodado esfuerzo del franciscano Alonso Muñoz ante el Consejo de Indias no consiguió la adhesión de las autoridades hispanas. Por su parte, la que debe ser llamada “segunda embajada de la era Keichô”, que llevaba a su frente a Tsunenaga Hasekura, llegó a Sevilla cuando ya podía considerarse definitivo el fracaso de las negociaciones, pese a lo cual obtuvo en su momento una mayor visualización y hasta ahora una mayor resonancia historiográfica.

  11. Escritos en el lenguaje del exilio

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    Mónica Marinone

    2014-06-01

    Full Text Available El ensayo explora textos de Augusto Roa Bastos, un escritor modélico respecto de una experiencia de exilio compleja, siempre refigurada en su escritura. Si cualquier exilio geográfico implica un exilio de la lengua (Roa escribió su narrativa completa lejos del Paraguay, su propio sistema cultural se ve marcado, desde el dominio colonial hispánico, por una situación de “diglosia” como exilio (lingüístico/cultural constitutivo. Por ello apelo al concepto “lenguaje del exilio” y reviso desde un texto poético a una serie de relatos, ciertas  imágenes y metáforas que se alzan como signos del  trabajo de Roa sobre el castellano, una retórica que propicia el trazo de líneas y núcleos de resonancia y anclaje o  escritura superpuesta, entramada a la convencional.

  12. neuronales artificiales

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    Bartolomé Drozdowicz

    2005-01-01

    Full Text Available La segmentación de Imágenes de Resonancia Magnética (IRM es su descomposición en unidades naturales, tejidos normales (sustancia gris, sustancia blanca, fluido cerebro espinal, etc. y posibles tejidos patológicos (tumores, edema, etc. Las IRM son una herramienta de diagnóstico estándar, y, a diferencia de los otros métodos de estudios por imagen (TAC, PET, etc., tienen características multidimensionales, ya que existen diferentes modalidades para generar las imágenes (T1, T2, DP, que son utilizadas para conformar los patrones empleados durante el entrenamiento y el testeo de las redes. La segmentación es particularmente importante en aplicaciones como: extracción de características anatómicas, medición volumétrica, visualización 3D, compresión de datos, planeamiento de radioterapia y planeamiento de cirugía. El objetivo de la investigación cuyos resultados se exponen fue explorar el potencial de diferentes estructuras de redes neuronales para realizar la segmentación de IRM del cerebro y analizar los diferentes procesos de preprocesamiento de datos, necesarios para obtener la mayor eficiencia de las redes.

  13. Enfermedad de moyamoya, macrocefalia y déficit intelectual en un adolescente

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    José Vargas Díaz

    2013-03-01

    Full Text Available El patrón moyamoya se caracteriza por un estrechamiento crónico progresivo de la porción terminal de la arteria carótida interna o sus principales ramas terminales principalmente. Los niños con moyamoya típicamente se presentan con ictus arteriales isquémicos, o con accidentes isquémicos transitorios. Se presenta el caso clínico de un adolescente, con déficit intelectual y macrocránea, con evidencia en los estudios de resonancia magnética nuclear cerebral de infartos arteriales isquémicos a repetición, e imágenes sugestivas de moyamoya, y se comprueba el patrón moyamoya por angiografía de sustracción digital. Comprobado el diagnóstico de enfermedad de moyamoya, el objetivo con este enfermo fue tratar de mejorar la irrigación cerebral, planteando la necesidad de someter al paciente a cirugía de revascularización, y, mientras esto no fuera posible, usar aspirina como antiagregante plaquetario, en un intento de impedir o disminuir el riesgo de nuevos infartos cerebrales o de accidentes transitorios isquémicos a repetición.

  14. Adolescente con inestabilidad lumbosacra por presencia de quiste hidatídico: reporte de caso

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    Miguel Vizcarra

    Full Text Available La hidatidosis, causada por el Echinococcus granulosus, afecta a la columna vertebral en 0,5-2% del total de casos, siendo la columna sacra una ubicación rara, típica de personas en edad adulta. Se reporta el caso de un varón de 14 años oriundo de Juliaca (Puno, Perú quien presentó lumbalgia crónica y síndrome de cauda equina. Atendido inicialmente en Juliaca, fue trasladado al Hospital Edgardo Rebagliati Martins (Lima, Perú con el diagnóstico de tumoración sacra. En la resonancia magnética se mostró una tumoración multiquística con lisis del L5 y S1 e inestabilidad. El tratamiento quirúrgico fue una laminectomía L5-S2 y extracción de múltiples quistes de hidátide más estabilización lumbopélvica con tornillos transpediculares. En el posoperatorio se recetó albendazol (15 mg/kg/d por el periodo de seis meses. Se debe considerar al quiste hidatídico dentro del diagnóstico diferencial cuando existan lesiones quísticas en la columna vertebral, sobre todo en regiones endémicas como el Perú.

  15. Linfoma primario del sistema nervioso central en una paciente con lupus eritematoso sistémico

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    C. N. Pisoni

    2003-06-01

    Full Text Available Se presenta una paciente de 36 años con diagnóstico de lupus eritematoso sistémico tratada con prednisona y ciclofosfamida que se internó por cefalea, hemiparesia y hemianestesia braquiocrural derecha de dos semanas de evolución. Se realizó una tomografía computada y una resonancia magnética nuclear de cerebro que mostraron una lesión nodular frontal izquierda. Se efectuó una biopsia a cielo abierto de la lesión cerebral cuyo diagnóstico histopatológico fue linfoma B de celulas grandes, difuso. Se inició radioterapia, no completó el tratamiento por complicaciones y falleció. Son muy pocos los casos publicados de linfoma primario del sistema nervioso central asociado a lupus eritematoso sistémico.A 36 year-old woman with systemic lupus erythematosus was admitted to our hospital with headache, brachiocrural hemiparesis and hemianesthesia. She had been treated with prednisone and cyclophosphamide. CT scan and MRI revealed a 15 mm nodular mass enhanced with gadolinium in left frontal convexity. CNS biopsy was performed and a diffuse large B-cell lymphoma was diagnosed. She was treated with radiation therapy without response and died. There are few reports of erythematosus systemic lupus associated with primary central nervous system lymphoma.

  16. Desinserción espontánea y bilateral del tendón cuadricipital.

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    Jesuan Zordan

    2016-02-01

    Full Text Available La ruptura espontánea bilateral del tendón cuadricipital es una patología infrecuente (<5% de todas las rupturas cuadricipitales. El mayor número de casos reportados, se asocia a insuficiencia renal crónica,  obesidad, diabetes, lupus eritematoso sistémico, vasculitis e hiperparatiroidismo. Nuestro paciente, de 41 años de edad presenta insuficiencia renal crónica en tratamiento con hemodiálisis desde hace 8 años, asociada a hiperparatiroidismo secundario. Ingresa a nuestro servicio por incapacidad a la extensión de ambos miembros inferiores, tras incorporarse desde una silla, destacando en el examen físico una depresión palpable suprarrotuliana. Se realizan radiografías de ambas rodillas frente y perfil, ecografía de zona suprarrotuliana y resonancia magnética nuclear. Al  constatar lesión bilateral a nivel del tendón cuadricipital, se programa su reparación quirúrgica, la cual se realizó por cuestiones ajenas a nuestro servicio a los 30 días del diagnóstico. Se intervinieron de manera simultánea ambas rodillas utilizando como técnica, tunelización patelar y empleando suturas no reabsorbible. Se obtuvo un resultado excelente en ambos miembros inferiores según el Score Knee Society (S.N.S..

  17. Estética y Trabajo Social. El protagonismo de lo sensible

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    Alberto Carreras

    2005-11-01

    Full Text Available La Estética no se ocupa únicamente del arte o de la belleza, aunque habitualmente así se crea. Por el contrario, ella es el ámbito de todo lo sensible, es decir, del conocimiento sensorial y de las emociones producidas por las sensaciones. El artículo resalta la importancia de la sensibilidad en la actuación de los trabajadores sociales. Toma en cuenta tanto las sensaciones que recibimos nosotros como las que producimos en los demás. Desde esta perspectiva se abordan temas como la capacidad de observación, la inteligencia emocional, los estilos de vida, los estilos de trabajo, la resonancia, la sintonía con el cliente o el síndrome del profesional «quemado». Más aún, este ámbito de las sensaciones no está lejos del mundo teórico sino que es su punto de partida y su piedra de toque. En realidad, el mundo abstracto no existe sin el sensible. Y uno y otro tienen una dimensión relacional y ética. De este modo, el artículo termina criticando la separación de la ciencia, la estética y la ética como «esferas» de la cultura.

  18. La escritura intermedial en la escena actual

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    Luis Thenon

    2013-08-01

    Full Text Available Las escrituras artísticas actuales integran, en el marco determinado por las realidades intermediales de la escena tecnológica, el concepto de diseño como manipulación perceptiva del espacio, lo que constituye uno de los instrumentos determinantes en la puesta en marcha de un cuadro compositivo de resonancias transformacionales. Podríamos en este sentido hablar de una nueva ecología artística y en especial, teatral. En la renovación del pensamiento teatral actualizado, fuertemente influenciado por la estructura discursiva cinematográfica y por los universos sensoriales de la cultura tecnológica de la imagen y del sonido, está la base de la multiplicación diegética, de la superposición, de la fragmentación de los discursos y de la praxis inter-relacional en la que radica, en gran medida, la potencia intermedial de la escena actual.

  19. Meningitis granulomatosa, glomerulonefritis rápidamente progresiva y vasculitis

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    Ana Ludueña

    2011-08-01

    Full Text Available El compromiso meníngeo es una manifestación infrecuente de la granulomatosis de Wegener. Puede manifestarse como cefalea con hiperproteinorraquia y engrosamiento de la duramadre con aspecto granulomatoso, que se observa en la resonancia magnética. Presentamos un varón de 57 años con granulomatosis de Wegener que debutó con compromiso de vías aéreas superiores, oídos, órbitas y meningitis granulomatosa asintomática y que posteriormente evolucionó con mononeuritis múltiple y glomerulonefritis crescéntica ANCA positiva. La presencia de ANCA y el compromiso sistémico (vías aéreas superiores, oído, órbitas, nervios periféricos, duramadre y glomerulonefritis rápidamente progresiva permitieron en este caso llegar a un diagnóstico de certeza e iniciar el tratamiento inmunosupresor combinado (corticoides y ciclofosfamida. Evolucionó con remisión clínica y serológica (negativización de ANCA, pero persistiendo leve deterioro secuelar auditivo y de la función renal, sin recidiva de la enfermedad de base.

  20. Paquimeningitis hipertrófica, glomerulonefritis y vasculitis de pequeños vasos asociada a ANCA Hypertrophic pachymeningitis, glomerulonephritis and P-ANCA associated small vessel vasculitis

    Directory of Open Access Journals (Sweden)

    Octavio Mazzocchi

    2007-04-01

    Full Text Available La paquimeningitis hipertrófica es una enfermedad poco frecuente caracterizada por engrosamiento de la duramadre. Presentamos una paciente con esta enfermedad que se manifestó con cefalea crónica y en la que concomitantemente se evidenció una glomerulonefritis necrotizante extracapilar pauciinmune asociada a anticuerpos anticitoplasma de neutrófilos de patrón perinuclear (ANCA-P. El diagnóstico se estableció por resonancia nuclear magnética. Recibió tratamiento inmunosupresor con prednisona y ciclofosfamida con evolución favorable.Hypertrophic pachymeningitis is a very unusual disease, the main characteristic of which is thickening of the dura mater. We describe a patient who started this illness showing chronic headache and pauci-immune necrotizing extracapillary perinuclear antineutrophil cytoplasmic antibody (P-ANCA associated glomerulonephritis. The diagnosis was made by brain magnetic resonance image. She received immunosuppressant therapy with prednisonel and cyclophosphamide with clinical improvement.