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Search Results: 1 - 10 of 656510 matches for " J. A. García-Macedo "
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Decoloración fotocatalítica homogénea y heterogénea de un colorante azoico, empleando como catalizador dióxido de titanio dopado con hierro soportado sobre sílice (Fe/TiO2/SiO2)
S. L. Orozco-Cerros,J. M. Barrera-Andrade,G. Valverde-Aguilar,J. A. García-Macedo
Tecnología, Ciencia, Educación , 2010,
Abstract: En esta investigación se presentan los resultados de la decoloración fotocatalítica homogénea y heterogénea de un colorante azoico, anaranjado de metilo, empleando catalizadores de TiO2 dopados con iones de hierro soportados sobre una matriz de sílice, Fe/TiO2/SiO2. El fotocatalizador Fe/TiO2/SiO2 fue preparado por la técnica sol-gel, en una relación molar de 0.01:0.02:1.0, respecto a la sílice. Adicionalmente, se prepararon los materiales Fe/SiO2 (a una relación molar de 0.01:1) y TiO2/SiO2 (a una relación molar de 0.02:1) por impregnación, como fotocatalizadores de control. Los materiales Fe/SiO2, TiO2/SiO2 y Fe/TiO2/ SiO2 fueron sometidos a un tratamiento térmico a 550°C por 24 horas. La caracterización física y óptica de los fotocatalizadores fue realizada empleando espectroscopía vibracional IR y óptica y difracción de rayos X. Los resultados de la caracterización demuestran que el fotocatalizador Fe/TiO2/SiO2 presenta una banda de absorción en la región visible desde 400 a 600 nm, lo que permitirá un uso más eficiente de la energía solar. Los resultados del proceso de decoloración de anaranjado de metilo demuestran que proceso se lleva a cabo principalmente por fotocatálisis heterogénea. La contribución de la fotocatálisis homogénea es mínima, debido a que la concentración de los iones de hierro en solución de muy baja, del orden de 0.5 mg L-1.
Evaluación de la degradación de un colorante textil usando el fotocatalizadores Fe/TiO2/SiO2 (0.0, 0.5, 0.7, 1.0 % en masa Fe) y en presencia de H2O2
José Manuel Barrera-Andrade,Sayra Lissette Orozco-Cerros,Guadalupe Valverde-Aguilar,Jorge A. García-Macedo
Tecnología, Ciencia, Educación , 2011,
Abstract: En este trabajo se evalúa la degradación de un colorante textil antraquinónico empleando fototalizadores de TiO2 dopados con iones de Fe soportado sobre SiO2, Fe/TiO2/SiO2. Los foto-catalizadores fueron sintetizados para diferentes contenidos de Fe (0, 0.5, 0.7, 1.0% en masa), empleando la técnica de sol-gel. Como fuente de sílice fue empleada sílice pirogénica (tama o de partícula 0.007 um y área superficial de 390±40 m2 g-1) y los precursores de titanio y hierro fueron TiCl4 y Fe(NO3)3, respectivamente. Los soles de TiO2 fueron preparados vía peptización ácida del precipitado de la solución de TiCl4 con NH3H2O. La proporción de TiO2, en los foto-catalizadores Fe/TiO2/SiO2, fue de 10% en masa. Los materiales sintetizados fueron sometidos a un tratamiento térmico de 550°C por 3 horas. Los foto-catalizadores Fe/TiO2/SiO2 se caracterizaron por espectroscopía óptica, en modo de reflectancia difusa UV-Vis-NIR y difracción de rayos X. La degradación del colorante textil se efectuó en solución acuosa en presencia de H2O2 a pH de 3.0. El proceso de degradación fue llevado a cabo en un reactor intermitente (tipo batch) y bajo radiación UV-A. Los resultados demuestran que la actividad catalítica de los fotocatalizadores se incrementó con la introducción de 0.7% de Fe en la matriz TiO2/SiO2.
Adipocinas, tejido adiposo y su relación con células del sistema inmune
Sánchez-Mu?oz, Fausto;García-Macedo, Rebeca;Alarcón-Aguilar, Francisco;Cruz, Miguel;
Gaceta médica de México , 2005,
Abstract: a dipokines or adipocytokines are the proteins secreted by the adipose tissue. these bioactive molecules include proteins that modify insulin sensitivity (acylation stimulating protein (asp), tnf-a, il- 6, resistin, leptin and adiponectin), and proteins that have known effects on vascularity (angiotensinogen and the plasminogen inhibitor protein pai-1). several studies have found a close relationship between adipocytes and immune cells as a consequence of evolutionary mechanisms that favor metabolic adaptation and survival under adverse conditions. it is known that adipokines contribute to the inflammation and insulin resistance present in obese individuals. the aim of this review is to analyze current information related to the physiology of the adipose tissue, with a special emphasis on the secretion of adipokines and their role in inflammation. we recommend that therapies addressing the treatment of obesity related disorders should focus on modifying the inflammatory process that originates in the adipose tissue.
El papel de la inmunidad innata en la obesidad
Fortis,ángeles; García-Macedo,Rebeca; Maldonado-Bernal,Carmen; Alarcón-Aguilar,Francisco; Cruz,Miguel;
Salud Pública de México , 2012, DOI: 10.1590/S0036-36342012000200014
Abstract: obesity in mexico is alarmingly increasing in prevalence in adults and children, and it is a risk factor for the development of insulin resistance, as well as, of other metabolic alterations. the discovery of the expression of the toll-like receptors (tlrs) in adipocytes, suggests an important role in innate immunity. in different models of obesity, there has been observed an increase of tlrs expression in the fat tissue, therefore tlrs could be involved in systemic inflammation in this disease, and in the development of insulin resistance. tlr activation is mediated by fatty acids and their expression is regulated by leptin, adiponectin and ppars. knowledge of the role of tlrs in inflammation and adipocyte differentiation and their regulation, then it is important to try to develop new therapeutic anti-inflammatory targets that contribute in the treatment of obesity.
Effect of lamellar nanostructures on the second harmonic generation of polymethylmethacrylate films doped with 4-(4-nitrophenylazo)aniline chromophores
Alfredo Franco,Laura Romero-Miranda,Guadalupe Valverde-Aguilar,Jorge García-Macedo,Giovanna Brusatin,Massimo Guglielmi
Physics , 2011,
Abstract: The kinetics of the orientation of Disperse Orange 3 molecules embedded in amorphous and nanostructured Polymethylmethacrylate films was studied under the effect of an intense electrostatic poling field. Non-centrosymmetric chromophore distributions were obtained in Polymethylmethacrylate films by Corona poling technique. These distributions depends on the Corona poling time. The changes in the orientation of the Disperse Orange 3 molecules were followed by in-situ transmitted Second Harmonic Generation measurements. The Second Harmonic Generation signal was recorded as function of time at several temperatures; it was fitted as function of the Corona poling time, considering matrix-chromophore interactions. The Polymethylmethacrylate films were nanostructured by the incorporation of an anionic surfactant, the Sodium Dodecyl Sulfate. The lamellar nanostructures in the films were identified by X-ray diffraction measurements.
Adiponectin in eutrophic and obese children as a biomarker to predict metabolic syndrome and each of its components
Miguel Klünder-Klünder, Samuel Flores-Huerta, Rebeca García-Macedo, Jesús Peralta-Romero, Miguel Cruz
BMC Public Health , 2013, DOI: 10.1186/1471-2458-13-88
Abstract: A cross sectional study was conducted in 190 school-age children classified as obese and 196 classified as eutrophic. Adiponectin, glucose, insulin, high density lipoprotein cholesterol (HDL-C) and triglycerides were determined from a fasting blood sample. Height, weight, waist circumference, systolic and diastolic blood pressures (BP) were measured; MetS was evaluated with the IDF definition. The study groups were divided according to tertiles of adiponectin, using the higher concentration as a reference. Linear regression analysis was used to assess the association between adiponectin and components of the MetS. Finally, stepwise forward multiple logistic regression analysis controlling for age, gender, basal HOMA-IR values and BMI was performed to determine the odds ratio of developing MetS according to adiponectin tertiles.Anthropometric and metabolic measurements were statistically different between eutrophic and obese children with and without MetS (P <0.001). The prevalence of MetS in obese populations was 13%. Adiponectin concentrations were 15.5?±?6.1, 12.0?±?4.8, 12.4?±?4.9 and 9.4?±?2.8 μg/mL for eutrophic and obese subjects, obese without MetS, and obese with MetS, respectively (P <0.001). Obese children with low values of adiponectin exhibited a higher frequency of MetS components: abdominal obesity, 49%; high systolic BP, 3%; high diastolic BP, 2%; impaired fasting glucose, 17%; hypertriglyceridemia, 31%; and low HDL-C values, 42%. Adjusted odds ratio of presenting MetS according to adiponectin categories was 10.9 (95% CI 2.05; 48.16) when the first tertile was compared with the third.In this sample of eutrophic and obese Mexican children we found that adiponectin concentrations and MetS components have an inversely proportional relationship, which supports the idea that this hormone could be a biomarker for identifying individuals with risk of developing MetS.During the last three decades, obesity has emerged worldwide as an epidemic affecting all age
Tratamento cirúrgico para ectasia anulo-aórtica
García-Macedo, Ricardo;Kalil, Renato A. K;Prates, Paulo Roberto;Lucchese, Fernando A;Sant'Ana, Jo?o Ricardo;Pereira, Edemar M;Costa, Altamiro Reis;Lara, Raul Feck A;Nesralla, Ivo A;
Revista Brasileira de Cirurgia Cardiovascular , 1986, DOI: 10.1590/S0102-76381986000100007
Abstract: this is a report of 27 patients presenting annulo-aortic ectasia submitted to surgical correction with a composite valve-tube graft (bentall-de bono technique), between 1976 and 1985. twenty three (85.2%) had cystic medial necrosis, 3 (11,1%) were chronic aortic disections and 1 (3.7%) was luetic aortitis. age ranged from 29 to 64 years (m = 48). three were female and 24 male patients. the valves used were homologous dura maier in 7 cases, heterologous aorta in 9 and mechanical prosthesis in 11. functional class (nyha) was i-ii in 7 and iii-iv in 9 patients. there was 1 (3.7%) hospital death, due to bleeding and renal failure. significant early complications were represented by arrhythmias in 13 cases (48%) and bleeding in 3 (11%). in the late follow-up therev.were 9 deaths, due to: sudden death (2 patients, 7.4%), bleeding in reoperation (1 patient, 3.7%), hospital infection (1 patient, 3.7%), infectious endocarditis (1 patient, 3.7%) and accidental causes (2 patients, 7.4%). five patients (18.5%) needed reoperation in the late follow-up: 2 due to bioprosthetic failure, 2 for replacement of an infected dacron tube and 1 for repair of pseudo-aneurysm and periprosthetic leak. the actuarial survival curve showed a probability of 83.7% up to the 3rd. year, 61 % for the 5th. year and 42.7% from the 6th. to the 9th. year of follow-up. the 17 patients surviving are in functional class i-ii (nyha). the composite valve-dacron tube graft (bentall-de bono) technique for correction of annulo-aortic ectasia is associated with a low hospital mortality. the improvement in functional class is significant. there have been a small number of complications and the long term survival is very satisfactory.
Different Ways of Perceiving the Aging Process: Social Behaviors of Women and Men in Relation to Age Discrimination  [PDF]
Alfonso J. García, Yolanda Troyano
Psychology (PSYCH) , 2013, DOI: 10.4236/psych.2013.43A041
Abstract:

Based on the original survey “Relating to Older People Evaluation” (ROPE) by Cherry and Palmore (2008), we have elaborated the instrument Evaluation for Older Adults that consists of 20 items. In this project, we intend on studying the positive and negative behaviors which people have been able to inter- nalize during their daily life, as well as a previous psychometric analysis about the validity of the instru- ment. The sample is formed by, on one side, students of Psycho pedagogy, and the other side, older stu- dents that belong to the Class of Experience of the University of Seville. The results obtained suggest that the majority of the people take into consideration the positive behaviors, and both the young and the older adults reinforce the behaviors of and toward the older adults. It is important to highlight the significant differences as far as gender in relation to the internalization of positive behaviors, being more frequent in women than in men. In the discussion, we analyze the implications about social perception towards older people as a social phenomenon, as well as the strategies to reduce the negative behaviors towards older people in daily life.

PROPRIEDADES E APLICA ES DA TRANSGLUTAMINASE MICROBIANA EM ALIMENTOS*
J. A. MACEDO,H. H. SATO
Alimentos e Nutri??o , 2009,
Abstract: As propriedades e aplica § μes da transglutaminase (TGase) chamada de TGase microbiana (MTGase) descritas neste trabalho, se referem enzima proveniente de variantes de Streptomicys mobaraensis. A MTGase mostrou ser capaz de fazer liga § μes cruzadas em grande parte das prote -nas de alimentos, tais como case -nas, globulinas de soja, gl oten, actinas, miosinas e prote -nas de ovos, de forma t £o eficiente quanto as TGases de origem animal obtidas de mam -feros. Entretanto, ao contr rio de muitas outras TGases, a MTGase uma enzima c lcio-independente e possui um peso molecular relativamente baixo. Estas duas caracter -sticas s £o vantajosas no que diz respeito aplica § £o industrial desta enzima. Muitos estudos demonstram o grande potencial de aplica § £o das MTGases no processamento de alimentos e em outras reas. A MTGase vem sendo estudada com intuitos de modifica § £o de alimentos proteicos processados, implementando propriedades funcionais a produtos, ou como mostram alguns estudos, melhorando caracter -sticas como sabor, aroma e textura. Al m disso, o uso desta enzima mostrou aumentar o tempo de prateleira de determinados produtos e reduzir o potencial alerg anico de outros. PALAVRAS-CHAVE: Transglutaminase; propriedades funcionais e nutricionais; aplica § μes industriais.
Exactly Solvable Schr?dinger Equation with Hypergeometric Wavefunctions  [PDF]
J. Morales, J. García-Martínez, J. García-Ravelo, J. J. Pe?a
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.311173
Abstract: In this work, the canonical transformation method is applied to a general second order differential equation (DE) in order to trasform it into a Schr?dinger-like DE. Our proposal is based on an auxiliary function g(x) which determines the transformation needed to find exactly-solvable potentials associated to a known DE. To show the usefulness of the proposed approach, we consider explicitly their application to the hypergeometric DE with the aim to find quantum potentials with hypergeometric wavefunctions. As a result, different potentials are obtained depending on the choice of the auxiliary function; the generalized Scarf, Posh-Teller, Eckart and Rosen-Morse trigonometric and hyperbolic potentials, are derived by selecting g(x) as constant and proportional to the P(x) hypergeometric coefficient. Similarly, the choices g(x)~P(x)/x2 and g(x)~x2/P(x) give rise to a class of exactly-solvable generalized multiparameter exponential-type potentials, which contain as particular cases the Hulthén, Manning-Rosen and Woods-Saxon models, among others. Our proposition is general and can be used with other important DE within the frame of applied matematics and physics.
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