Autonomous University of Nayarit

www.uan.mx
Tepic, Mexico

The Autonomous University of Nayarit is a Mexican public university based in the city of Tepic, Nayarit, with several campuses across the state.Its library system holds more than 91,280 volumes in 29 libraries. Wikipedia.

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Ojeda J.A.,University of Colima | Messina S.,Autonomous University of Nayarit
Solar Energy | Year: 2017

We have developed a network of pipes of dendritic geometry in a solar collector with a disc-shaped body. The fluid in the network pipes is a nanofluid composed of a mixture of nanoparticles of alumina (Al2O3) and water as a base fluid in order to harvest a greater amount of thermal energy from incoming solar radiation. The sizes of the network pipes are obtained by using constructal theory methods. Thermal conductivity was obtained by the Hamilton-Crosser model; physical properties such as density and specific heat capacity were described as a function of the volumetric fraction of nanoparticles in the fluid. Optimal size of the network presented for every level of construction was established by the condition of minimal thermal resistance. Temperature profiles and the aspect ratio of the construction elements were defined as a function of the volumetric fraction of nanoparticles. Results show that by increasing the volume fraction of nanoparticles, thermal energy gain also increases, reaching a higher outlet temperature of the fluid when alumina nanoparticles are used. © 2017 Elsevier Ltd


Benites-Rengifo J.L.,Autonomous University of Nayarit | Vega-Carrillo H.R.,Autonomous University of Zacatecas | Velazquez-Fernandez J.,Autonomous University of Nayarit
Applied Radiation and Isotopes | Year: 2014

The spectrum of photoneutrons produced by a 15. MV VARIAN iX linac working in Bremsstrahlung mode was measured a 100. cm from the IC located 5. cm-depth of a solid water phantom. The spectrum was measured with a Bonner spheres spectrometer with pairs of TLDs as thermal neutron detector. The measurements were carried out using the spectrometer in planetary method mode where a single shoot of the LINAC was required. © 2013 Elsevier Ltd.


Yarza S.,Autonomous University of Nayarit
Numerical Functional Analysis and Optimization | Year: 2017

In this work, we present a decomposition of the scattering matrix for higher-order Sturm-Liouville problems in terms of scattering matrices associated to disjointly supported potentials. Consequently, we propose a numerical method to approximate the eigenvalue problem. It is shown that the theory and numerics apply to the non self-adjoint case. © 2017 Taylor & Francis.


Zambrano-Zaragoza J.F.,Autonomous University of Nayarit | Romo-Martinez E.J.,Polytechnic University of Sinaloa | Duran-Avelar M.D.J.,Autonomous University of Nayarit | Garcia-Magallanes N.,Polytechnic University of Sinaloa | Vibanco-Perez N.,Autonomous University of Nayarit
International Journal of Inflammation | Year: 2014

The view of CD4 T-cell-mediated immunity as a balance between distinct lineages of Th1 and Th2 cells has changed dramatically. Identification of the IL-17 family of cytokines and of the fact that IL-23 mediates the expansion of IL-17-producing T cells uncovered a new subset of Th cells designated Th17 cells, which have emerged as a third independent T-cell subset that may play an essential role in protection against certain extracellular pathogens. Moreover, Th17 cells have been extensively analyzed because of their strong association with inflammatory disorders and autoimmune diseases. Also, they appear to be critical for controlling these disorders. Similar to Th1 and Th2 cells, Th17 cells require specific cytokines and transcription factors for their differentiation. Th17 cells have been characterized as one of the major pathogenic Th cell populations underlying the development of many autoimmune diseases, and they are enhanced and stabilized by IL-23. The characteristics of Th17 cells, cytokines, and their sources, as well as their role in infectious and autoimmune diseases, are discussed in this review. © 2014 José Francisco Zambrano-Zaragoza et al.


Rodriguez-Carpena J.-G.,Autonomous University of Nayarit | Morcuende D.,University of Extremadura | Andrade M.-J.,University of Extremadura | Kylli P.,University of Helsinki | Estevez M.,University of Extremadura
Journal of Agricultural and Food Chemistry | Year: 2011

The first aim of the present work (study 1) was to analyze ethyl acetate, 70% acetone, and 70% methanol extracts of the peel, pulp, and seed from two avocado (Persea americana Mill.) varieties, namely, 'Hass' and 'Fuerte', for their phenolic composition and their in vitro antioxidant activity using the CUPRAC, DPPH, and ABTS assays. Their antimicrobial potential was also studied. Peels and seeds had higher amounts of phenolics and a more intense in vitro antioxidant potential than the pulp. Peels and seeds were rich in catechins, procyanidins, and hydroxycinnamic acids, whereas the pulp was particularly rich in hydroxybenzoic and hydroxycinnamic acids and procyanidins. The total phenolic content and antioxidant potential of avocado phenolics was affected by the extracting solvent and avocado variety. The avocado materials also displayed moderate antimicrobial effects against Gram-positive bacteria. Taking a step forward (study 2), extracts (70% acetone) from avocado peels and seeds were tested as inhibitors of oxidative reactions in meat patties. Avocado extracts protected meat lipids and proteins against oxidation with the effect on lipids being dependent on the avocado variety. © 2011 American Chemical Society.


Rodriguez-Carpena J.G.,Autonomous University of Nayarit | Morcuende D.,University of Extremadura | Estevez M.,University of Extremadura
Meat Science | Year: 2011

Processing of avocados generates an important amount of by-products such as peels and seeds that are rich in bioactive substances with proven radical suppressing activities. The objective of this study was to evaluate the effectiveness of peel and seed extracts from two avocado varieties-'Hass' and 'Fuerte'-as inhibitors of lipid and protein oxidation and color deterioration of raw porcine patties during chilled storage (4 °C/15. days). Avocado extracts significantly (p < 0.05) reduced the loss of redness and the increase of lightness during storage of porcine patties. 'Fuerte' extracts were more efficient at inhibiting discoloration of chilled patties than 'Hass' extracts. Patties treated with avocado extracts had significantly lower amounts of TBA-RS than control ones throughout the storage. 'Hass' avocado extracts significantly inhibited the formation of protein carbonyls in chilled patties at day 15. The present results highlight the potential usage of extracts from avocado by-products as ingredients for the production of muscle foods with enhanced quality traits. © 2011 Elsevier Ltd.


Utrera M.,University of Extremadura | Morcuende D.,University of Extremadura | Rodriguez-Carpena J.-G.,Autonomous University of Nayarit | Estevez M.,University of Extremadura
Meat Science | Year: 2011

Precise methodologies for the routine analysis of particular protein carbonyls are required in order to progress in this topic of increasing interest. The present paper originally describes the application of an improved method for the detection of α-aminoadipic and γ-glutamic semialdehydes in a meat system by using a derivatization procedure with p-amino-benzoic acid (ABA) followed by fluorescent high-performance liquid chromatography (HPLC). The method development comprises i) the description of a simple HPLC program which allows the efficient separation of the ABA and the key standard compounds and ii) the optimization of the procedure for the preparation of a meat sample in order to maximize the fluorescent signal for both protein carbonyls. Furthermore, the suitability of this method is evaluated by applying the technique to porcine burger patties. The present procedure enables an accurate and relatively fast analysis of both semialdehydes in meat samples in which they could play an interesting role as reliable indicators of protein oxidation. © 2011 Elsevier Ltd.


Utrera M.,University of Extremadura | Rodriguez-Carpena J.-G.,Autonomous University of Nayarit | Morcuende D.,University of Extremadura | Estevez M.,University of Extremadura
Journal of Agricultural and Food Chemistry | Year: 2012

The effects of the addition of avocado oil and a phenolic-rich avocado peel extract on protein oxidation were studied in porcine patties subjected to cooking and chilled storage. Protein oxidation was assessed by means of tryptophan loss and the formation of specific lysine oxidation products, such as α-aminoadipic semialdehyde (AAS), α-aminoadipic acid (AAA), and Schiff bases. In the present paper, quantitative data of AAA are reported for the first time on a food matrix. The addition of the avocado extract inhibited the formation of AAS, AAA, and Schiff bases in patties during cooking and subsequent chilled storage. The antioxidant effect may respond to the protecting effect of phenolic compounds, mainly procyanidins, found on the avocado extract. Apparently, the combination of both strategies (back-fat replacement and addition of avocado extract) does not lead to an enhanced advantage on the oxidative stability of the product. The novel methodologies used in the present study enable a better comprehension of the mechanisms and consequences of protein oxidation in food systems. © 2012 American Chemical Society.


Rodriguez-Carpena J.G.,Autonomous University of Nayarit | Morcuende D.,University of Extremadura | Estevez M.,Autonomous University of Nayarit
Meat Science | Year: 2012

The present study investigates the effects of avocado, sunflower and olive oils used as back-fat replacers, on the fatty acid composition, oxidative stability, volatiles profile and color and texture properties of cooked pork patties. The vegetable oils modified the fatty acid profiles of the patties by lowering the percentages of SFA (from 36.96% to ~. 25.30%) and reducing the atherogenic index (from 0.41 to ~. 0.24). Vegetable oils had higher amounts of antioxidant compounds such as tocopherols (10.8-53.9. mg/100. g) than back-fat (5.9. mg/100. g). Consistently, patties manufactured with the oils had significantly lower amounts of lipid and protein oxidation products than control patties. Avocado oil contributed with specific aroma-active terpenes to patties and had a significant impact on particular color and texture parameters. The results from this study highlight the technological applications of the vegetable oils as food ingredients in the design of healthier meat commodities. © 2011 Elsevier Ltd.


Montalvo-Gonzalez R.,Autonomous University of Nayarit | Ariza-Castolo A.,Research Center y
Magnetic Resonance in Chemistry | Year: 2012

A structural and conformational analysis of 1-oxaspiro[2.5]octane and 1-oxa-2-azaspiro[2.5]octane derivatives was performed using 1H, 13C, and 15N NMR spectroscopy. The relative configuration and preferred conformations were determined by analyzing the homonuclear coupling constants and chemical shifts of the protons and carbon atoms in the aliphatic rings. These parameters directly reflected the steric and electronic effects of the substituent bonded to the aliphatic six-membered ring or to C3 or N2. The parameters also were sensitive to the anisotropic positions of these atoms in the three-atom ring. The preferred orientation of the exocyclic substituents directed the oxidative attack. © 2012 John Wiley & Sons, Ltd.

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