oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 558 )

2018 ( 859 )

2017 ( 783 )

2016 ( 1153 )

Custom range...

Search Results: 1 - 10 of 487019 matches for " Gerardo Ramírez-Mejía "
All listed articles are free for downloading (OA Articles)
Page 1 /487019
Display every page Item
Motor Effects of 1,3-Disubstituted 8-Styrylxanthines as A1 and A2 Adenosine-Receptor Antagonists in Rats  [PDF]
Ilhuicamina Daniel Limón-Pérez de León, María del Carmen Parra-Cid, Alejandro Mu?oz-Zurita, Saúl Alejandro Merino-Contreras, Sara Montiel-Smith, Socorro Meza-Reyes, Gerardo Ramírez-Mejía, Jesús Sandoval-Ramírez
Pharmacology & Pharmacy (PP) , 2013, DOI: 10.4236/pp.2013.43044
Abstract:

A series of 1,3-substituted 8-styrylxanthines (11a-d) was synthesized, under chemo- and regioselective conditions, in a good overall yield. The compounds showed affinity towards both A1 and A2A-adenosine receptors by radioligand binding by means of in vitro assays. The (E)-3-ethyl-1-propyl-8-styrylxanthine (11a) showed the greatest affinity towards the A2A receptor, whereas (E)-3-pentyl-1-propyl-8-styrylxanthine (11d) showed the greatest affinity for the A1 receptor. When the 8-styrylxanthines 11a (A15Et) and 11c (A15Bu) were administrated in rats, which were previously injured with 6-hydroxydopamine at the substantia nigra pars compacta (SNc), the turning behavior decreased 50%. Based on these results we propose to A15Et as a potential compound to treat some symptoms of Parkinson’s disease.

Contribution to the study of the mycobiota present in the natural habitats of Histoplasma capsulatum: an integrative study in Guerrero, Mexico
Ulloa, Miguel;Lappe, Patricia;Aguilar, Samuel;Park, Houng;Pérez-Mejía, Amelia;Toriello, Conchita;Taylor, Maria Lucia;
Revista mexicana de biodiversidad , 2006,
Abstract: the mycobiota present in natural habitats of histoplasma capsulatum was determined in samples of bat guano, poultry droppings, and intestinal contents of bats. the following fungi were isolated: 1) from bat guano: the ascomycetes aphanoascus fulvescens, gymnascella citrina, gymnoascus dankaliensis, and chaetomidium fimeti; the mitosporic fungi aspergillus flavo-furcatis, a. terreus, a. terreus var. aureus, penicillium spp., malbranchea aurantiaca, and sporothrix sp.; and the yeasts candida catenulata, c. ciferrii, c. famata var. flareri, c. guilliermondii var. guilliermondii, and rhodotorula spp. 2) from poultry droppings: the coelomycete phoma sp.; and the yeasts c. albicans, c. catenulata, c. ciferrii, c. famata var. flareri, c. tropicalis, cryptococcus albidus, trichosporon moniliiforme, and trichosporon spp. 3) from the intestinal contents of insectivorous, hematophagous, nectarivorous, and frugivorous bats: ch. fimeti; the mitosporic fungi aspergillus candidus, a. flavo-furcatis, a. sulphureus, a. sydowii, a. terreus, a. versicolor, aspergillus sp., m. aurantiaca, gliomastix murorum, and scopulariopsis sp.; and c. famata var. flareri, c. lipolytica, cr. albidus, and trichosporon spp. most of the species found are first records for these substrata and environments in mexico. the coexistence with h. capsulatum was demonstrated by high specific antibody titers in elisa serological method, using sera from balb/c mice previously inoculated with the supernatant of the different samples studied.
Photoluminescence Spectroscopy as a Tool for Quality Control of GaN Thin Film to Be Used in Solar Cell Devices  [PDF]
Guillermo Santana-Rodríguez, Adolfo Mejía-Montero, Betsabeé Marel Monroy-Peláez, Máximo López-López, Yenny Lucero Casallas-Moreno, Manolo Ramírez-López, Gerardo Contreras-Puente, Osvaldo de Melo-Pereira
Materials Sciences and Applications (MSA) , 2014, DOI: 10.4236/msa.2014.55031
Abstract:

The use of III-V and semiconductor nitrides in solar cells has been of interest in the PV-community due to the wide variation range of the band gap in these materials. Particularly, the processing of hetero-junction structures of InGaN/GaN and Si(p)/GaN(n) has been of great interest recently. In this work, the quality of GaN and InGaN thin films grown by Molecular Beam Epitaxy (MBE) on different substrate and buffer layers has been studied by photoluminescence spectroscopy (PL). The PL measurements were processed as function of sample temperature and pump power. In the PL spectra it is possible to observe a strong near band-gap-edge emission and a broad blue, green and yellow luminescence (BL, GL, YL), which can be assigned to the presence of Ga and N vacancies, amorphous phases, deep level impurities and structural defects. The relative intensity between the different peaks of the bands related to defects or impurities was studied as a tool for quality control of the films.

Congenital contractural arachnodactyly Síndrome de la arcnodactilia contractural: estudio de un caso esporádico y revisión de la literatura
José Luis Ramírez Castro,Amanda Mejía,Betty Nishikuni
Iatreia , 1991,
Abstract: The Congenital Contractural Arachnodactyly Syndrome is a heredltary disorder of connective tissue characterized by multiple congenital contractures, arachnodactyly, dolichostenomella, kyphoscollosis, abnormalities of the external ears and autosomal dominant inheritance. Nearly 50 cases have previously been reported. A new sporadic case is presented. Some clinical and genetic aspects, differential diagnosis and therapeutic approach of this syndrome are discussed. El síndrome de la aracnodactilia contractural es una alteración hereditaria del tejido conectivo, caracterizada por múltiples contracturas congénitas, aracnodactilia, dolicostenomelia, cifoescoliosis, dismorfia de los pabellones auriculares y un patrón de herencia autonómico dominante. Se han Informado aproximadamente 50 casos, a los cuales se adiciona uno nuevo, esporádico. Se discuten algunos aspectos clínicos y genéticos, el diagnóstico diferencial y el manejo de estos pacientes.
Reconstrucción Tridimensional de Imágenes Ecocardiográficas
Sergio Mejía,Juan Giraldo,Jan Ramírez
Iatreia , 2001,
Abstract: Las imágenes ecocardiográficas convencionales permiten la evaluación anatómica y funcional del corazón; por ser bidimensionales son difíciles de interpretar sin un entrenamiento adecuado; los últimos desarrollos han estado orientados a la reconstrucción del corazón en 3 y 4 dimensiones directamente en el equipo de ultrasonido o usando programas especializados. El objetivo es un software en MATLAB para la reconstrucción 3D y 4D de imágenes ecocardiográficas.
Reintegración sin desmovilización: el caso de las milicias populares de Medellín
Jorge Giraldo Ramírez,Juan Pablo Mesa Mejía
Colombia Internacional , 2013, DOI: 10.7440/colombiaint77.2013.08
Abstract: Narratives on peace processes in Colombia do not often include the 1994 negotiations with the so-called "popular militia" in Medellín. This article analyzes the development and results of this process, revises the explanations of its failure which were produced in that time, and proposes an interpretation that appeals to a more profound institutional structure that gave way to the negotiation of disorder and the privatization of security, thus developing a thesis suggested by María Teresa Uribe.
About radial Toeplitz operators on Segal-Bargmann and $l^2$ spaces
Romina A. Ramírez,Gerardo L. Rossini,Marcela Sanmartino
Mathematics , 2010,
Abstract: We discuss Toeplitz operators on the Segal-Bargmann space as functional realizations of anti-Wick operators on the Fock space. In the special case of radial symbols we exploit the isometric mapping between the Segal-Bargmann space and $l^2$ complex sequences in order to establish conditions such that an equivalence between Toeplitz operators and diagonal operators on $l^2$ holds. We also analyze the inverse problem of mapping diagonal operators on $l^2$ into Toeplitz form. The composition problem of Toeplitz operators with radial symbols is reviewed as an application. Our notation and basic examples make contact with Quantum Mechanics literature.
Monitoría hemodinámica no invasiva en Síndrome Hellp
Monsalve Mejía,Germán; Rodríguez Fraile,José Ramón; Vasco Ramírez,Mauricio;
Revista Colombiana de Anestesiología , 2006,
Abstract: the hellp (hemolysis, elevated liver enzymes, low platelets) syndrome is a serious complication that affects around 10% pregnancies with severe preeclampsia-eclampsia [1]. most of the patients with a diagnosis of hellp syndrome come to light after 27 weeks? gestation. when the cardiovascular system compromise is severe, the invasive monitoring is frequent in order to make a guided therapeutic and reduce the complications. albeit the use of the pulmonary artery catheter is reported in patients with severe preeclampsia and associated hellp syndrome with serious cardiovascular compromise and refractory oliguria, there is a risk of mayor complications associated with central punctures in these patients with severe thrombocytopenia [2]. the hemosonic 100 (arrow international, reading, pa) uses transesophageal doppler ultrasound to measure the aortic blood flow in a non-invasive way and beat by beat in real time. we report the use of hemosonic 100 during the cesarean section of a patient with hellp syndrome in order to optimize the intraoperatory cardiovascular management.
Monitoría hemodinámica no invasiva en Síndrome Hellp
Germán Monsalve Mejía,José Ramón Rodríguez Fraile,Mauricio Vasco Ramírez
Revista Colombiana de Anestesiología , 2006,
Abstract: El síndrome HELLP (hemólisis, elevación de las enzimas hepáticas y trombocitopenia) es una complicación grave que afecta cerca del 10% de los embarazos con diagnóstico de preeclampsia severa y eclampsia (1). La mayor parte de las pacientes con diagnóstico de síndrome HELLP se presentan después de las 27 semanas de edad gestacional y cuando el compromiso del aparato cardiovascular es severo. Es frecuente la necesidad de monitoría invasiva para realizar una terapéutica guiada y disminuir las complicaciones, aunque el uso del catéter de arteria pulmonar se ha reportado en pacientes con diagnóstico de preeclampsia severa asociado a síndrome HELLP con compromiso cardiovascular severo u oliguria refractaria; existe un riesgo de complicaciones mayores asociado a las punciones centrales en estas pacientes con trombocitopenia severa(2). El Hemosonic 100 (Arrow Internacional, Reading, PA) utiliza técnicas de ultrasonido Doppler por vía transesofágica para medir el flujo sanguíneo aórtico de manera no invasiva y de una manera latido a latido en tiempo real. Nosotros reportamos el uso del Hemosonic 100 durante la cesárea en una paciente con síndrome HELLP con el fin de optimizar el manejo cardiovascular intraoperatorio. The HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome is a serious complication that affects around 10% pregnancies with severe preeclampsia-eclampsia [1]. Most of the patients with a diagnosis of HELLP syndrome come to light after 27 weeks’ gestation. When the cardiovascular system compromise is severe, the invasive monitoring is frequent in order to make a guided therapeutic and reduce the complications. Albeit the use of the pulmonary artery catheter is reported in patients with severe preeclampsia and associated HELLP syndrome with serious cardiovascular compromise and refractory oliguria, there is a risk of mayor complications associated with central punctures in these patients with severe thrombocytopenia [2]. The HEMOSONIC 100 (Arrow International, Reading, PA) uses transesophageal Doppler ultrasound to measure the aortic blood flow in a non-invasive way and beat by beat in real time. We report the use of HEMOSONIC 100 during the cesarean section of a patient with HELLP syndrome in order to optimize the intraoperatory cardiovascular management.
Effect of Nicotine on Dopamine and Glutathione Levels in Presence of Oligoelements in Brain Regions of Young Rats——Effect of Nicotine on Brain Regions of Rat  [PDF]
David Calderón Guzmán, Ernestina Hernández García, Francisca Trujillo Jiménez, Gerardo Barragán Mejía, Hugo Juárez Olguín, José A. Saldivar González, Daniel Santamaria del Angel, Norma Osnaya Brizuela
Neuroscience & Medicine (NM) , 2012, DOI: 10.4236/nm.2012.33032
Abstract: Aim: The purpose of this study was to understand the mechanism of nicotine mediated addiction and the role of oligoelements in reducing its effect. Methods: Male Wistar rats (weight 80 g) were treated with single and repeated doses of nicotine and/or oligoelements as follows: group 1 (control) NaCl 0.9%; group 2, nicotine (1 mg/kg); group 3, oligoelements (50 μl/rat); and group 4, nicotine (1 mg/kg) + oligoelements (50 μl/rat). All drugs were intraperitoneally administered for 4 days. Blood for the measurement of glucose was obtained from all the animals. Samples of the brain regions (cortex, hemispheres and cerebellum + medulla oblongata) of each rat were obtained and used to measure the concentrations of dopamine, GSH levels, and lipid peroxidation (TBARS) using fluorescence and spectrophotometric methods. Results: Glucose level increased in rats treated with nicotine and oligoelements (p < 0.05), while GSH level decreased in cerebellum/medulla oblongata and hemispheres (p < 0.05) of the same animals. TBARS levels increased in cerebellum/medulla oblongata and hemispheres of animals treated with nicotine and oligoelements, but decreased in the same regions (p < 0.05) in rats treated only with oligoelements. The levels of dopamine decreased in cortex and hemispheres, but increased in cerebellum/medulla and oblongata regions of rats treated with both compounds (p < 0.05). Conclusions: Nicotine and oligoelements are associated with increase in the level of glucose, an effect that was more pronounced in the group treated with both drugs. Reduction of oxidative stress and dopamine metabolism may be involved in this effect.
Page 1 /487019
Display every page Item


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