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Search Results: 1 - 10 of 200980 matches for " Rebeca;Alarcón-Aguilar "
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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.
Developing Ontology Systems as a Base of an Environmental Quality Management Model in México  [PDF]
René Bernardo Elías Cabrera-Cruz, Erika Alarcón-Ruiz, Julio César Rolón-Aguilar, Salvador W. Nava-Díaz, Elena María Otazo-Sánchez, Ricardo Pérez Aviléz
Journal of Environmental Protection (JEP) , 2015, DOI: 10.4236/jep.2015.69095
Abstract: The process of identifying the attributes and relationships considered in an ontology is a complex task because there are many factors involved in the deterioration of environmental quality, the diversity of sources and data dispersion. This work presents an ontology that integrates the data required by an Environmental Quality Synoptic System (EQSS), which to date scatters in different Internet sites and concentrates by different agencies for example INEGI, CONABIO, SEMARNAT, CNA, among others. The methodology process consists of the collection of environmental information in Mexico through the application of computational techniques resulting ontology with environmental knowledge that will be processed by the system EQSS. Among the main advantages is than the selection and structure of information allow the automated generation of results in an environmental statement. The ontology proposal is based on knowledge of EQSS system that is based on the architecture of expert systems and through this important information for decision-making in regard to environmental quality and interaction with Geographic Information System (GIS) is obtained.
Security Regulations in Mexican Renewable Energies: Case of Geothermal Projects  [PDF]
Alfonso Aragón-Aguilar, Georgina Izquierdo-Montalvo, Víctor Arellano-Gómez
Smart Grid and Renewable Energy (SGRE) , 2013, DOI: 10.4236/sgre.2013.46A003
Abstract:

A review of natural resources existing in México is done. The description of the renewable energies for electricity generation operating at date along the country, includes hydro, wind, solar, biomass and geothermal, among others. The installed capacity (to 2012) in México for electric generation from renewable energies is equivalent to 22% of total generation capacity. México has geothermal resources, which can be classified as high and low enthalpy, and of hot dry rock. To date, the exploitation has focused mainly on high enthalpy geothermal fields. Geothermal power plants do not burn fuel, preventing gas emissions helping to reduce global warming and greenhouse effect. Security risks in México geothermal fields, as a part of renewable energies linked to Smart Grids, are described emphasizing their geographical locations to facilitate the exposure to dangerous events. The results about research on Mexican Official Norms protecting environment related with geothermal operation projects are shown. The Mexican geothermal projects have developed under rules that provide security to workers and people, avoiding impacts on the environment. However, it was found that it necessarily emphasized previsions to damages and remedial actions for grids due to risks by natural contingencies (cyclones, winds, earthquakes) and by artificial causes such as vandalism (grids breaking, fire, explosions, etc.). Unfortunately, there are no preventive norms against natural risks. After all the analyses carried out, security must be considered by nature a dynamic and ever-changing process.

Hypoglycemic Activity of Aqueous Extracts from Catharanthus roseus
Elisa Vega-ávila,José Luis Cano-Velasco,Francisco J. Alarcón-Aguilar,María del Carmen Fajardo Ortíz,Julio César Almanza-Pérez,Rubén Román-Ramos
Evidence-Based Complementary and Alternative Medicine , 2012, DOI: 10.1155/2012/934258
Abstract: Introduction. Catharanthus roseus (L.) is used in some countries to treat diabetes. The aim of this study was to evaluate the hypoglycemic activity of extracts from the flower, leaf, stem, and root in normal and alloxan-induced diabetic mice. Methods. Roots, leaves, flowers, and stems were separated to obtain organic and aqueous extracts. The blood glucose lowering activity of these extracts was determinate in healthy and alloxan-induced (75 mg/Kg) diabetic mice, after intraperitoneal administration (250 mg/Kg body weight). Blood samples were obtained and blood glucose levels were analyzed employing a glucometer. The data were statistically compared by ANOVA. The most active extract was fractioned. Phytochemical screen and chromatographic studies were also done. Results. The aqueous extracts from C. roseus reduced the blood glucose of both healthy and diabetic mice. The aqueous stem extract (250 mg/Kg) and its alkaloid-free fraction (300 mg/Kg) significantly () reduced blood glucose in diabetic mice by 52.90 and 51.21%. Their hypoglycemic activity was comparable to tolbutamide (58.1%, ). Conclusions. The best hypoglycemic activity was presented for the aqueous extracts and by alkaloid-free stem aqueous fraction. This fraction is formed by three polyphenols compounds.
Kikuchi-Fujimoto Disease Associated to the Epstein-Barr Virus. A Type of Rare Necrotizing Lymphadenitis and Its Differential Diagnosis  [PDF]
Mónica Belinda Romero Guadarrama, Oscar Daniel Guzmán-Aguilar, Adriana Carolina López-Ugalde, José Samuel Almeida Navarro, Humberto Cruz-Ortíz
Open Journal of Pathology (OJPathology) , 2013, DOI: 10.4236/ojpathology.2013.34034
Abstract: Introduction: Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a specific and self-limited disease; its etiology is unknown. Some causal microorganisms have been proposed. The objective of the present article is to emphasize the clinicopathological characteristics of this disease that has been associated to the Epstein-Barr virus and to compare the histological changes with other types of necrotizing lymphadenopathies. Material and Methods: We studied 32 patients of the Surgical Pathology Service with necrotizing lymphadenitis, diagnosed in the years from 2004 to 2012 to found more cases of this rare disease in our Institution. Patients were 18 women and 14 men with an average age of 37 years. Results: The lymph nodes were cervical and axillary ones, some were associated to autoimmune diseases and no cause was identified in others. One of the cases, was diagnosed as KFD, presented morphological changes characteristic of this disease, such as subcapsular lymphoid follicles, zones with cell debris, epithelioid macrophages, clear-cytoplasm histiocytes, and immunoblast-reactive lymphocytes. Immunohistochemical markers were determined, such as CD20, CD2, CD4, CD8, CD68, lysozyme, CD56, granzyme B and EBER, which demonstrated the presence of B, T lymphocytes, histiocytes and cells positive to EBER. Histological changes in KFD occurred in three stages: proliferative stage, necrotizing, and xanthomatous. It is important to identify the histological stages of the disease because a differential diagnosis must be performed in regard to lymphadenopathies with necrosis and diverse types of lymphomas. Conclusion: We present a case of necrotizing lymphadenitis (KFD) associated to the Epstein-Barr virus and in some cases it is not possible to render a specific diagnosis based on morphologic findings, alone, and a diagnosis of necrotizing lymphadenitis may be used.

 

Methodological and biological factors explaining the reduction in dental caries in Jamaican school children between 1984 and 1995
Warpeha,Rosalie; Beltrán-Aguilar,Eugenio; Báez,Ramón;
Revista Panamericana de Salud Pública , 2001, DOI: 10.1590/S1020-49892001000700006
Abstract: objective. to assess the methods used and results found in two surveys, one conducted in 1984 and the other in 1995, that indicated a large reduction in the prevalence and severity of dental caries among children in jamaica, with special attention focused on methodological differences between the two surveys and the biological factors that may explain the large reduction in caries. methods. in 1984 a modified "pathfinder" methodology was used to measure the prevalence and severity of dental caries in 6-, 12-, and 15-year-old children in jamaica. a similar survey was conducted in 1995. a comparison of the two surveys showed an 84% reduction in the severity of dental caries at age 12. both surveys used the same diagnostic criteria and clinical procedures, but the 1984 survey included a higher proportion of rural residents than did the 1995 one. results. the data show an epidemiological transition between 1984, when dental caries was highly prevalent and severe, and 1995, when the disease was less prevalent and was concentrated in a smaller proportion of the population. conclusions. most of the reduction in dental caries between 1984 and 1995 is attributable to the introduction, in 1987, of salt fluoridation. while the 1995 survey included fewer rural areas than the 1984 survey did, that does not invalidate the observed reduction in dental caries. the use of fluoride toothpaste and dietary fluoride supplements as well as access to dental health promotion and preventive and curative services do not seem to be major contributors to the reductions observed.
Methodological and biological factors explaining the reduction in dental caries in Jamaican school children between 1984 and 1995
Warpeha Rosalie,Beltrán-Aguilar Eugenio,Báez Ramón
Revista Panamericana de Salud Pública , 2001,
Abstract: Objective. To assess the methods used and results found in two surveys, one conducted in 1984 and the other in 1995, that indicated a large reduction in the prevalence and severity of dental caries among children in Jamaica, with special attention focused on methodological differences between the two surveys and the biological factors that may explain the large reduction in caries. Methods. In 1984 a modified "pathfinder" methodology was used to measure the prevalence and severity of dental caries in 6-, 12-, and 15-year-old children in Jamaica. A similar survey was conducted in 1995. A comparison of the two surveys showed an 84% reduction in the severity of dental caries at age 12. Both surveys used the same diagnostic criteria and clinical procedures, but the 1984 survey included a higher proportion of rural residents than did the 1995 one. Results. The data show an epidemiological transition between 1984, when dental caries was highly prevalent and severe, and 1995, when the disease was less prevalent and was concentrated in a smaller proportion of the population. Conclusions. Most of the reduction in dental caries between 1984 and 1995 is attributable to the introduction, in 1987, of salt fluoridation. While the 1995 survey included fewer rural areas than the 1984 survey did, that does not invalidate the observed reduction in dental caries. The use of fluoride toothpaste and dietary fluoride supplements as well as access to dental health promotion and preventive and curative services do not seem to be major contributors to the reductions observed.
Shark breeding grounds and seasons in the Gulf of California: Fishery management and conservation strategy
Salomón-Aguilar, CA;Villavicencio-Garayzar, CJ;Reyes-Bonilla, H;
Ciencias marinas , 2009,
Abstract: sharks show high biological fragility and, given the intense fishing regimes to which they are exposed in the gulf of california, it is necessary to establish a conservation and management strategy providing for the protection of their nursery areas. we reviewed the literature concerning shark reproductive biology to determine priority management areas in the gulf of california by complementarity analysis and different selection criteria. four levels of management and conservation priority were determined for six quadrants: level 1 corresponded to the area off mazatlán (sinaloa) and the area of el sargento, la ventana, and punta arenas (baja california sur); level 2 to the areas of teacapán (sinaloa) and seri (sonora); level 3 to the areas of san francisquito-el barril (baja california) and kino bay (sonora); and level 4 to the area of la manga (sonora). analysis of space-time variables in a geographic information system indicated that 71% of the commercially important shark species concentrate in coastal zones, mainly in bays, coastal lagoons, estuaries, and wetlands (central and southern gulf of california) during spring and summer (may-august), except for prionace glauca, isurus oxyrinchus, alopias pelagicus, and squatina californica that reproduce in winter and spring. the protection of recruitment areas (critical habitats) during peak breeding periods should be an essential part of any resource management plan.
HIGH- EFFICIENCY CLASS E POWER AMPLIFIER USING SI-GE HBT TECHNOLOGY
J.A. Tirado-Méndez,H. Jardón-Aguilar
Journal of applied research and technology , 2004,
Abstract: One of the most important goals of RF circuit designers is improving efficiency and autonomy in handsets forpersonal communications. Currently, low-level voltage supplies are used to avoid big weight and volume. Besides,autonomy and efficiency are closely linked to the energy consumed by the circuits. Power Amplifier (PA) is one ofthe circuits, which spends more energy from the battery. Improving the PA efficiency, handset performance is alsoimproved. Previous publications have mentioned the difference of power amplifiers where the circuit output worksas I) a current source or II) as a switch. The class E power amplifiers are devices whose output works as a switchachieving great performance and high power efficiency, reaching, in an ideal case, 100 % of efficiency. In thispaper, a low-level voltage class E power amplifier is analyzed, designed, simulated, built and characterized, using asilicio-Germains HBT transistor as an active element. The circuit was optimized using a harmonic balanced simulator(Microwave Office [1]). 70% power efficiency was measured after an optimizing procedure, although betterperformance can be expected with an improved switching transistor and more precisely lumped elements. Theprototype was designed to operate at 900 MHz and fed with 2.4 V, but it is well known that low-level polarizationvoltages affect efficiency, linearity, power gain, bandwidth, noise figure, as well as cost in RF circuits. However theclass E PA reported in this paper reaches high efficiency, high power gain as well as a good bandwidth, with lowlevelpolarization voltage.
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