oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 133 )

2019 ( 600 )

2018 ( 662 )

2017 ( 637 )

Custom range...

Search Results: 1 - 10 of 420321 matches for " Vicente Río Vázquez "
All listed articles are free for downloading (OA Articles)
Page 1 /420321
Display every page Item
Mecanismos fisiopatológicos de las alteraciones cardiovasculares en el Síndrome de apnea obstructiva del sue?o
Río Vázquez,Vicente; Anías Calderón,José;
Revista Cubana de Investigaciones Biom??dicas , 2009,
Abstract: in cuba, mortality and morbidity of cardiovascular disease is high, justifying the study of physiopathologic mechanisms associating the syndrome of sleep obstructive apnea syndrome (soas) with cardiovascular diseases. patients presenting with soas have anatomic, muscular, and neurologic factors favoring closure of high airway (ha). obstruction provokes hypoxia, increases of a negative intrathoracic pressure, and sympathetic discharges associated with frequent awakenings. the high intrathoracic negative pressure decreases the left ventricular fill, and the cardiac output. as an adaptation response to this dysfunction, it is produced a sympathetic activation as well as a release of atrial natriuretic peptide raising very much the arterial pressure. episodes of hypoxia-re-oxygenation in these patients produce an imbalance in vascular homeostasis, and an endothelial dysfunction, favoring low-density lipoproteins oxidation, generating vascular structural changes and also favoring appearance of cardiovascular diseases.
Mecanismos fisiopatológicos de las alteraciones cardiovasculares en el Síndrome de apnea obstructiva del sue o Physiopathologic mechanisms of cardiovascular alterations in sleep obstructive apnea syndrome
Vicente Río Vázquez,José Anías Calderón
Revista Cubana de Investigaciones Biom??dicas , 2009,
Abstract: En Cuba la morbimortalidad de las enfermedades cardiovasculares es alta, lo que motivó a estudiar los mecanismos fisiopatológicos que asocian el síndrome de apnea obstructiva del sue o (SAOS) con las enfermedades cardiovasculares. Los pacientes con SAOS presentan factores anatómicos, musculares y neurológicos que favorecen el cierre de la vía aérea superior (VAS). La obstrucción provoca hipoxia, incrementos de la presión negativa intratorácica y descargas simpáticas asociadas a los despertares frecuentes. La presión negativa intratorácica elevada disminuye el llenado ventricular izquierdo y el gasto cardiaco. Como respuesta adaptativa a esta disfunción se produce activación simpática y liberación de péptido natriurético atrial que elevan considerablemente la presión arterial. Los episodios de hipoxia-reoxigenación en estos pacientes producen desequilibrio en la homeostasia vascular y disfunción endotelial, favoreciendo la oxidación de las lipoproteínas de baja densidad, lo que genera cambios estructurales vasculares. Todos estos cambios favorecen la aparición de enfermedades cardiovasculares. In Cuba, mortality and morbidity of cardiovascular disease is high, justifying the study of Physiopathologic mechanisms associating the syndrome of sleep obstructive apnea syndrome (SOAS) with cardiovascular diseases. Patients presenting with SOAS have anatomic, muscular, and neurologic factors favoring closure of high airway (HA). Obstruction provokes hypoxia, increases of a negative intrathoracic pressure, and sympathetic discharges associated with frequent awakenings. The high intrathoracic negative pressure decreases the left ventricular fill, and the cardiac output. As an adaptation response to this dysfunction, it is produced a sympathetic activation as well as a release of atrial natriuretic peptide raising very much the arterial pressure. Episodes of hypoxia-re-oxygenation in these patients produce an imbalance in vascular homeostasis, and an endothelial dysfunction, favoring low-density lipoproteins oxidation, generating vascular structural changes and also favoring appearance of cardiovascular diseases.
Aspectos patogénicos de la enfermedad descompresiva en buzos Etiopathogenic aspects of the decompression illness in divers
Vicente Río Vázquez,Alberto Salda?a Bernabeu,Leonel Téllez Traba,Urbano Leyva Moreno
Revista Cubana de Medicina Militar , 2005,
Abstract: En los últimos a os la incidencia de la enfermedad descompresiva en Cuba se ha elevado. Para que se presente esta enfermedad los buzos deben respirar una mezcla gaseosa que contenga uno o más gases inertes (por ejemplo: nitrógeno, helio, hidrógeno), y deben permanecer un tiempo y a una profundidad determinada para que se produzca una saturación considerable de gas inerte en los tejidos. En esas condiciones es imprescindible realizar durante el ascenso paradas estáticas por el buzo para eliminar el sobrante de gas inerte que se acumula en los tejidos. Si se omiten estas paradas se producirá una sobresaturación excesiva de gas inerte que puede alcanzar el punto crítico de sobresaturación a partir del cual el gas cambia de estado y forma burbujas. Estas burbujas que pueden ser intravasculares y/o extravasculares son las responsables del cuadro sintomático de la enfermedad descompresiva. The incidence of the decompression illness in Cuba has increased in the last years. For this sickness to appear, the divers should breath a gaseous mix containing one or more inert gases (for instance: nitrogen, helium, hydrogen) and they should remain under water for a time and at a certain depth so that a considerable saturation of inert gas occurs in the tissues. Under these conditions, it is indispensable that the diver makes static stops to eliminate the excess of inert gas accumulated in the tissues. If the diver does not do so, an excessive oversaturation of inert gas will occur that may reach the critical point of oversaturation, starting from which the gas changes of state and makes bubbles.These bubbles that may be intravascular and/or extravascular are the responsible for the symptomatic picture of the decompression illness.
Numerical Prediction for the Size and Shape of a Flare in a Cross–Wind
W. Vicente y Rodríguez,M. Salinas–Vázquez,E.R. Barrera–Avenda?o
Ingeniería, investigación y tecnología , 2009,
Abstract: A computational fluid–dynamics model is used to simulate the turbulent combustion in a flare exposed to a cross–wind. Our research is mostly focused on the cross flow velocity influence to flame aerodynamics. The flow simulation is performed as three dimensional along a Cartesian coordinates system. In order to simulate the combustion process, a fast–chemistry model with a 1–step global irreversible reaction to form CO2 and H2O is used. A radiation model is used to identify the mean flame trajectory. The simulated configuration consists in a propane discharge into an air stream, get ting oxygen supply from the cross–wind. The velocity of this cross–flow is increased from 0.8 m/s to 12 m/s. Comparative analysis of our predicted values with respect to available experimental results shows good agreement in terms of flame length as well as inclination angles.
Efecto de la privación de sue?o sobre la presión arterial en ratas
de la Portilla Teresa-Calleja,Tahumara; Anías Calderón,José; Chao González,Susana; Río Vázquez,Vicente;
Revista Cubana de Investigaciones Biom??dicas , 2009,
Abstract: with the objective of evaluating the effects of chronic sleep deprivation on the systolic blood pressure, three groups of 8 wistar rats were studied- a control group with no sleep deprivation and two experimental groups subjected to total sleep deprivation and mor sleep phase deprivation, respectively- for continuous 96h periods weekly throughout 2 months. systolic blood pressure was taken in all the three groups every week before starting the sleep deprivation period. after two months, their kidneys were extracted. the results yielded that there was a statistically significant difference between the control group and the group subjected to total sleep deprivation. as to the histological study of the kidney cuts, nephrosclerosis alterations were not found. in the study model the total sleep deprivation brings about a remarkable rise in systolic blood pressure, except for the group which underwent mor sleep phase deprivation and that renal morphological alterations does not seem to be involved in hypertension resulting from the applied techniques.
Aspectos patogénicos de la enfermedad descompresiva en buzos
Río Vázquez,Vicente; Salda?a Bernabeu,Alberto; Téllez Traba,Leonel; Leyva Moreno,Urbano; Torres Perdomo,José E.;
Revista Cubana de Medicina Militar , 2005,
Abstract: the incidence of the decompression illness in cuba has increased in the last years. for this sickness to appear, the divers should breath a gaseous mix containing one or more inert gases (for instance: nitrogen, helium, hydrogen) and they should remain under water for a time and at a certain depth so that a considerable saturation of inert gas occurs in the tissues. under these conditions, it is indispensable that the diver makes static stops to eliminate the excess of inert gas accumulated in the tissues. if the diver does not do so, an excessive oversaturation of inert gas will occur that may reach the critical point of oversaturation, starting from which the gas changes of state and makes bubbles.these bubbles that may be intravascular and/or extravascular are the responsible for the symptomatic picture of the decompression illness.
Neumoencéfalo secundario a barotrauma durante el buceo
Río Vázquez,Vicente; Gil Cruz,Juan José; Téllez Traba,Leonel; Batista Mesa,Bárbara Vivian;
Revista Cubana de Medicina Militar , 2003,
Abstract: the case of a diver that submerged at a depth of 25 meters and on arriving to the surface had occipital intense headache with dizziness and nausea was reported. later, he presented taking of conciousness and neurological focalization. in antero-posterior and lateral radiographies and computerized tomography of the cranium it was observed a large pneumocephalus in the left hemisphere and an osteoma in the left frontal sinus. left frontotemporal craniotomy with evacuation of the pneumocephalus was performed. neurological improvement was observed and 48 hours later he died due to a respiratory infection. the osteoma eroded the posterior wall of the frontal and subdural sinus, which allowed the accumulation of subdural air and prevented its extraction by a mechanism of dural valve.
Neumoencéfalo secundario a barotrauma durante el buceo
Vicente Río Vázquez,Juan José Gil Cruz,Leonel Téllez Traba,Bárbara Vivian Batista Mesa
Revista Cubana de Medicina Militar , 2003,
Abstract: Se presenta el caso de un buzo que realizó una inmersión a 25 m de profundidad y al llegar a la superficie se le instaló un cuadro de cefalea occipital intensa con mareos y náuseas. Posteriormente presentó toma de la conciencia y focalización neurológica. En radiografía antero-posterior y lateral, tomografía computadorizada de cráneo, se observó un gran neumoencéfalo en hemisferio izquierdo y en osteoma en el seno frontal izquierdo. Se realizó una craneotomía frontotemporal izquierda con evacuación del neumoencéfalo. Posteriormente se observó mejoría neurológica y 48 h más tarde fallece por una infección respiratoria. El osteoma erosionó la pared posterior del seno frontal y subdural, lo que permitió la acumulación de aire subdural y no su salida por un mecanismo de válvula dural. The case of a diver that submerged at a depth of 25 meters and on arriving to the surface had occipital intense headache with dizziness and nausea was reported. Later, he presented taking of conciousness and neurological focalization. In antero-posterior and lateral radiographies and computerized tomography of the cranium it was observed a large pneumocephalus in the left hemisphere and an osteoma in the left frontal sinus. Left frontotemporal craniotomy with evacuation of the pneumocephalus was performed. Neurological improvement was observed and 48 hours later he died due to a respiratory infection. The osteoma eroded the posterior wall of the frontal and subdural sinus, which allowed the accumulation of subdural air and prevented its extraction by a mechanism of dural valve.
Efecto de la privación de sue o sobre la presión arterial en ratas Effect of sleep deprivation on the blood pressure of rats
Tahumara de la Portilla Teresa-Calleja,José Anías Calderón,Susana Chao González,Vicente Río Vázquez
Revista Cubana de Investigaciones Biom??dicas , 2009,
Abstract: Con el objetivo de evaluar el efecto de la privación crónica de sue o sobre la presión arterial sistólica, se estudiaron 3 grupos de 8 ratas Wistar, un grupo control: sin privación de sue o y dos grupos experimentales: privación del sue o total y privación de fase de sue o MOR, durante períodos de 96 h continuas semanales, sin interrupción a lo largo de 2 meses. A dichos grupos se les midió la presión arterial sistólica cada semana antes de iniciar el período de privación de sue o. Al concluir los 2 meses, se les realizó extracción de ambos ri ones. Los resultados revelaron que hubo diferencia estadísticamente significativa a partir de la semana 6 entre el grupo control y el grupo con privación del sue o total. En cuanto al estudio histológico de los cortes de los ri ones, no se encontró alteración alguna de nefroesclerosis. En el modelo de estudio, la privación de sue o total produce un aumento notable de la presión arterial sistólica, no siendo así en el grupo con privación de fase de sue o MOR. Las alteraciones morfológicas renales no parecen participar en la hipertensión obtenida mediante las técnicas aplicadas. With the objective of evaluating the effects of chronic sleep deprivation on the systolic blood pressure, three groups of 8 Wistar rats were studied- a control group with no sleep deprivation and two experimental groups subjected to total sleep deprivation and MOR sleep phase deprivation, respectively- for continuous 96h periods weekly throughout 2 months. Systolic blood pressure was taken in all the three groups every week before starting the sleep deprivation period. After two months, their kidneys were extracted. The results yielded that there was a statistically significant difference between the control group and the group subjected to total sleep deprivation. As to the histological study of the kidney cuts, nephrosclerosis alterations were not found. In the study model the total sleep deprivation brings about a remarkable rise in systolic blood pressure, except for the group which underwent MOR sleep phase deprivation and that renal morphological alterations does not seem to be involved in hypertension resulting from the applied techniques.
Predicción numérica del tama?o y forma de una llama en un quemador elevado dentro de un flujo cruzado de aire
Vicente y Rodríguez, W.;Salinas-Vázquez, M.;Barrios-Bonilla, J.E.;Barrera-Avenda?o, E.R.;
Ingeniería, investigación y tecnología , 2009,
Abstract: a computational fluid-dynamics model is used to simulate the turbulent combustion in a flare exposed to a cross-wind. our research is mostly focused on the cross flow velocity influence to flame aerodynamics. the flow simulation is performed as three dimensional along a cartesian coordinates system. in order to simulate the combustion process, a fast-chemistry model with a 1-step global irreversible reaction to form co2 and h2o is used. a radiation model is used to identify the mean flame trajectory. the simulated configuration consists in a propane discharge into an air stream, get ting oxygen supply from the cross-wind. the velocity of this cross-flow is increased from 0.8 m/s to 12 m/s. comparative analysis of our predicted values with respect to available experimental results shows good agreement in terms of flame length as well as inclination angles.
Page 1 /420321
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.