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Search Results: 1 - 10 of 241374 matches for " Hernández-Pérez "
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Síndrome de fracaso en la cirugía espinal lumbar
Hernández-Pérez,P. A.;
Revista de la Sociedad Espa?ola del Dolor , 2007,
Abstract: introduction: the pain produced by degenerative disease of the spine in general and specially in the lumbar region, is a frequent motive of medical consult. the most patients improve their symptoms only with medical treatment, but some patients need surgical treatment. moreover, between 5 to 20% of patients don?t improve after surgery or relapse in the first year after surgery. objective: to analyze the causes of the failed back surgery syndrome, its treatment and methods for its prevention. the need of a multidisciplinary team for the evaluation of these patients is remarked. conclusions: in the degenerative disease of the lumbar spine, the surgery is a therapeutic option only on adequately selected cases. if the only symptom is pain, the team needs to define the kind of pain and to analyze the spinal anatomical alterations in the image studies. is very important to know how is the familiar and social environment. if it is necessary, neurophysiological studies can be made. a good selection of patients for surgical treatment and the best technique for each case is the main step for decrease the incidence of the failed back surgery syndrome.
Síndrome de fracaso en la cirugía espinal lumbar Failed back surgery syndrome
P. A. Hernández-Pérez
Revista de la Sociedad Espa?ola del Dolor , 2007,
Abstract: Introducción: El dolor generado por la patología degenerativa del raquis en general y de la región lumbar en particular, constituye uno de los motivos de consulta médica más frecuente. Si bien la mayoría de los pacientes mejoran con el tratamiento conservador, algunos requieren de tratamiento quirúrgico para intentar aliviar el dolor. A su vez, de los pacientes operados, entre el 5 y 20 % no mejoran o presentan una recaída de los síntomas en un período inferior a un a o luego de la cirugía. Objetivo: Analizar las causas del denominado sindrome de fracaso de la cirugía espinal lumbar, su tratamiento y métodos para su prevención, recalcando la necesidad de un equipo multidisciplinario para el diagnóstico y tratamiento de estos enfermos. Conclusiones: En la patología degenerativa del raquis lumbar, la cirugía debe reservarse como opción terapéutica solo para los pacientes que cumplan con los correspondientes criterios de selección. Cuando el único síntoma es el dolor lumbar o radicular, se debe definir claramente el tipo de dolor que presenta el paciente, como es su entorno familiar y social, realizar estudios neurofisiológicos si se considera necesario, y valorar las alteraciones anatómicas raquídeas mediante estudios de imagen. Una buena selección de los pacientes candidatos para cirugía y de la técnica adecuada en cada caso, es el paso fundamental para intentar disminuir la incidencia del fracaso de la cirugía espinal lumbar. Introduction: The pain produced by degenerative disease of the spine in general and specially in the lumbar region, is a frequent motive of medical consult. The most patients improve their symptoms only with medical treatment, but some patients need surgical treatment. Moreover, between 5 to 20% of patients don’t improve after surgery or relapse in the first year after surgery. Objective: To analyze the causes of the failed back surgery syndrome, its treatment and methods for its prevention. The need of a multidisciplinary team for the evaluation of these patients is remarked. Conclusions: In the degenerative disease of the lumbar spine, the surgery is a therapeutic option only on adequately selected cases. If the only symptom is pain, the team needs to define the kind of pain and to analyze the spinal anatomical alterations in the image studies. Is very important to know how is the familiar and social environment. If it is necessary, neurophysiological studies can be made. A good selection of patients for surgical treatment and the best technique for each case is the main step for decrease the incidence of the failed back surgery
Prensa digital y bibliotecas
Hernández-Pérez, Tony
Revista Espa?ola de Documentación Científica , 2010,
Abstract:
Revisiting binary stars in population synthesis models
Fabiola Hernández-Pérez,Gustavo Bruzual A
Physics , 2013, DOI: 10.1093/mnras/stt368
Abstract: We report results of a population synthesis model that follows the evolution of single and binary stars. In this model we include the 2HeWD merger channel, suggested by Han et al. (2002), for the formation of EHB stars. The physical parameters of the resulting EHB stars are derived from the BaSTI database, and are thus realistic and observationally supported. The predictions of this model are in good agreement with traditional population synthesis models, except when the spectrum of the stellar population is dominated by binary stars or their products, e.g., EHB stars in the UV of ETGs. We reproduce successfully the observed CMD and SED of the metal rich open cluster NGC 6791. The stellar population in this cluster may be archetypal of the stellar population in ETGs that show the UVX phenomenon. Our models should be appropriate to study the UV upturn in ETGs.
Binary stars and the UVX in early type galaxies
Fabiola Hernández-Pérez,Gustavo Bruzual
Physics , 2014, DOI: 10.1093/mnras/stu1627
Abstract: We use the Hern\'andez-P\'erez $\&$ Bruzual (2013) HB13 stellar population synthesis models to study the r\^ole of interacting binary pairs as progenitors of EHB stars. We assemble a sample of 3417 Early Type Galaxies observed both in the optical (\textit{SDSS}-DR8) and the UV (\textit{GALEX}-GR6). The galaxies in our sample can be classified according to their position in the colour-colour diagram as UV weak or red sequence galaxies ($\sim 48\%$), UV strong or UVX galaxies ($\sim 9\%$), and recent star forming galaxies ($\sim 43\%$). Analysing this sample using the HB13 models for various choices of basic model parameters we conclude that: (a) The UV$r$ colours of UV weak and UV strong galaxies are reproduced by the models as long as the fraction of binary stars is at least 15$\%.$ (b) Higher metallicity models ($Z = 0.02$ and $Z = 0.03$) reproduce the colours of UV weak and UV strong galaxies better than lower $Z$ models. The $Z = 0.03$ model is slightly bluer than the $Z = 0.02$ model in the UV strong region, indicating a weak relationship between UVX and $Z$. (c) The strength of UVX increases with age in the model population. This is at variance with the results of other models that include binary stars as progenitors of EHB stars.
Immunocytochemical study of estrogen receptor activation factor (E-RAF) and the proteins that interact with nuclear estrogen receptor II (nER II) in epithelial endometrial cells, in the presence and in the absence of estradiol
OM Echeverría,RV Thampan,S Juárez-Chavero,AD Hernández-Pérez
European Journal of Histochemistry , 2005, DOI: 10.4081/929
Abstract: The localization and abundance of the estrogen receptor activation factor (E-RAF) and a small nuclear ribonucleoprotein (snRNP) complex containing three proteins, p32, p55 and p60, which interact with the nuclear estrogen receptor II (nER II), have been studied in rat endometrial epithelial cells by means of immunofluorescence and high resolution quantitative immunocytochemistry. In the cytoplasm E-RAF is associated with the rough endoplasmic reticulum. In the nucleus it is mainly localized at the interchromatin space, and surrounding the clumps of compact or semi-condensed chromatin. Quantitative analyses show that the abundance of E-RAF in the nucleus increases after ovariectomy and decreases 3 minutes after estradiol administration. These results are in agreement with the currently available biochemical data. Double immunolocalizations demonstrate that p32, p55, p60 co-localize with other splicing-related protein. High resolution immunolocalization shows that p32, p55, p60 are associated with perichromatin fibrils (co-transcriptional splicing) and with clusters of interchromatin granules (storage of splicing-related molecules). The nuclear abundance of the snRNP complex decreases with ovariectomy, increases within 3 minutes after estradiol administration and remains higher than that in ovariectomized animals for 27 minutes. These results strongly support the previous data on the role of nER-II in the regulation of mRNA transcription and its export from the nucleus to the cytoplasm.
Análisis de las complicaciones de la cirugía de la hernia discal lumbar
Hernández-Pérez,P.A.; Prinzo-Yamurri,H.;
Neurocirugía , 2005, DOI: 10.4321/S1130-14732005000500003
Abstract: objective. to analyze the complications in a series of patients operated on for lumbar disc herniations between 1997 and 2002. methods. the records of 64 patients with the diagnosis of lumbar radicular compression by disc herniation who underwent 73 surgical procedures were analyzed. the patients with radicular pain without disc herniation were excluded. results. complications occurring in 7 cases (9.6 %) were 2 deep infections, 1 dural tear which was repaired, 2 cerebrospinal fluid fistulae, 1 pseudomeningocele and 1 lesion of l5 root. conclusions.- the most frequent complications were dural tear and infection. these observations are similar to those reported in previously published papers.
Análisis de las complicaciones de la cirugía de la hernia discal lumbar Analysis of the lumbar discectomy complications
P.A. Hernández-Pérez,H. Prinzo-Yamurri
Neurocirugía , 2005,
Abstract: Objetivo. Examinar los casos de hernia discal lumbar operados entre los a os 1997 y 2002, realizando un análisis de las complicaciones quirúrgicas, a la vez que se realiza una revisión de la literatura en relación con el tema. Material y métodos. Se revisaron las historias clínicas de 64 pacientes con diagnóstico de compresión radicular lumbar por hernia discal, sometidos a tratamiento quirúrgico, analizándose un total de 73 cirugías, incluyendo 9 reintervenciones realizadas en el período de tiempo definido al inicio. Resultados. Se presentaron complicaciones en 7 procedimientos (9.6%): 2 infecciones profundas, 1 caso de desgarro de la duramadre reparado, 2 casos de fístula de líquido cefalorraquídeo (LCR), 1 pseudomeningocele, y 1 caso de lesión de la raíz L5. Conclusiones. Las complicaciones que se presentaron con mayor frecuencia fueron los desgarros de la duramadre y las infecciones, resultados que coinciden con las series internacionales publicadas. Objective. To analyze the complications in a series of patients operated on for lumbar disc herniations between 1997 and 2002. Methods. The records of 64 patients with the diagnosis of lumbar radicular compression by disc herniation who underwent 73 surgical procedures were analyzed. The patients with radicular pain without disc herniation were excluded. Results. Complications occurring in 7 cases (9.6 %) were 2 deep infections, 1 dural tear which was repaired, 2 cerebrospinal fluid fistulae, 1 pseudomeningocele and 1 lesion of L5 root. Conclusions.- The most frequent complications were dural tear and infection. These observations are similar to those reported in previously published papers.
Distribución del género Bursera en el estado de Morelos, México y su relación con el clima
Hernández-Pérez, Ezequiel;González-Espinosa, Mario;Trejo, Irma;Bonfil, Consuelo;
Revista mexicana de biodiversidad , 2011,
Abstract: the influence of climatic variables on the distribution of 15 species of bursera in morelos mexico, was analyzed. data on the presence of species and climatic variables from 47 meteorological stations were obtained, and maps of actual and potential distribution were made using a gis; the influence of the main climatic variables on the distribution was analyzed by principal component and cluster analyses. the species of bursera are found in an altitudinal range of 800-2 800 m; species richness is higher in the warm, relatively dry areas south of the state. two main groups of species were distinguished: a), those having a restricted distribution, found mainly in warm sites and, b), those having a wider distribution, including relatively cool sites. precipitation, maximum and minimum temperatures, evapotranspiration and its seasonality, all influenced the distribution of the species. bursera bicolor, b. bipinnata, b. cuneata, b. copallifera, b. fagaroides, b. grandifolia and b. glabrifolia are found on sites having a relatively low minimum temperature (5-10° c) and high precipitation, while b. aptera, b. ariensis, b. lancifolia, b. linanoe, b. longipes, b. morelensis, b. schlechtendalii and b. submoniliformis are found in areas experiencing higher minimum temperatures (≥ 14° c) and relatively drier conditions.
MICROSCOPíA DE FUERZA ATóMICA Y MICROSCOPIA óPTICA IN SITU UTILIZADAS PARA ESTUDIAR LA ELECTROQUíMICA DE UN HETEROPOLYANION
Hernández-Pérez,T; Holguin,S; Rivera,M; Moreno,A;
Revista Latinoamericana de Metalurgia y Materiales , 2001,
Abstract: in this work, the electrochemical deposit of the [como6o18(oh)6]3- heteropolyanion (hpa) on a highly oriented pyrolytic graphite (hopg) electrode is studied by in situ afm and in situ optical microscopy (om). the electrochemical behavior of this material indicates that the hpa reduction originates a deposit of the compound by showing voltammograms similar to those found on the growth of an organic conducting polymer. the studies in the electrochemical module of the nanoscope iiia (afm-ec) showed that after hpa reduction (0.6 to- 1.5 v vs ag), some material is deposited on the hopg surface forming an irregular phase. meanwhile, by in situ om, it was observed that hpa changed from yellow to a "green-blue" color after electroreduction. this observation is the first one to be achieved for this hpa with an anderson-perlof structure. the thickness and shape of the new formed phase depended on both, the number of the potential scan cycles and the hpa concentration. results showed that in situ afm coupled to in situ om are useful to demonstrate and to follow electrodeposition of films of inorganic compounds which form irregular phases and present real changes in color.
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