584 research outputs found

    Homeostasis iónica y respuestas a estrés salino en levaduras

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    La homeostasis de cationes es fundamental para cualquier célula viva, especialmente cuando se encuentra en situaciones de estrés salino. Utilizando levaduras como organismo modelo de célula eucariota, se analiza la función de algunos de los transportadores de potasio y sodio así como sus procesos de regulació

    Colour and rheological properties of non-conventional grapefruit jams: instrumental and sensory measurement

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    Alternative methods with which to obtain grapefruit jams have been applied. These include the use of osmotic dehydration (OD) and/or microwave energy (MW), as an alternative to conventional heating, and the incorporation of bamboo fibre together with pectin in order to increase the jam's consistency. Colour, consistency and rheological behaviour were measured and sensory evaluation was carried out to compare product quality. When compared to the fresh fruit, the greatest colour changes took place in those jams processed by MW and conventional heating, both of them showing lower L*, a*, b* and chrome values than the rest of the samples obtained by applying osmotic dehydration. By adding bamboo fibre, the colour of OD samples approaches that of fresh fruit. The higher yield stress, greater consistency and more viscoelastic behaviour was displayed by jams obtained by combining OD and MW processes. In the sensory analysis, the judges awarded this sample a better score. The sensory attribute product coverage in mouth was closely related to viscosity at a shear rate of 120 s(-1) and consistency. (C) 2013 Elsevier Ltd. All rights reserved.Igual Ramo, M.; Contreras Monzón, CI.; Martínez Navarrete, N. (2014). Colour and rheological properties of non-conventional grapefruit jams: instrumental and sensory measurement. Food Science and Technology. 56(1):200-206. doi:10.1016/j.lwt.2013.10.038S20020656

    Niosomes based on synthetic cationic lipids for gene delivery: The influence of polar head-groups on the transfection efficiency in HEK-293, ARPE-19 and MSC-D1 cells

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    We designed niosomes based on three lipids that differed only in the polar-head group to analyze their influence on the transfection efficiency. These lipids were characterized by small-angle X-ray scattering before being incorporated into the niosomes which were characterized in terms of pKa, size, zeta potential, morphology and physical stability. Nioplexes were obtained upon the addition of a plasmid. Different ratios (w/w) were selected to analyze the influence of this parameter on size, charge and the ability to condense, release and protect the DNA. In vitro transfection experiments were performed in HEK-293, ARPE-19 and MSC-D1 cells. Our results show that the chemical composition of the cationic head-group clearly affects the physicochemical parameters of the niosomes and especially the transfection efficiency. Only niosomes based on cationic lipids with a dimethyl amino head group (lipid 3) showed a transfection capacity when compared with their counterparts amino (lipid 1) and tripeptide head-groups (lipid 2). Regarding cell viability, we clearly observed that nioplexes based on the cationic lipid 3 had a more deleterious effect than their counterparts, especially in ARPE-19 cells at 20/1 and 30/1 ratios. Similar studies could be extended to other series of cationic lipids in order to progress in the research on safe and efficient non-viral vectors for gene delivery purposes.This project was partially supported by the University of the Basque Country UPV/EHU (UFI 11/32), the National Council of Science and Technology (CONAYT), Mexico, Reg. # 217101, the Spanish Ministry of Education (Grant CTQ2010-20541, CTQ2010-14897), the Basque Government (Department of Education, University and Research, predoctoral BFI-2011-2226 grant), the Generalitat de Catalunya (2009SGR208, 2009SGR1331) and the Instituto de Salud Carlos III. Technical and human support provided by SGIker (UPV/EHU) is gratefully acknowledged. Authors also wish to thank the intellectual and technical assistance from the platform for Drug Formulation (NANBIOSIS) CIBER-BBN.Peer reviewe

    Optical and mechanical properties of cocona chips as affected by the drying process

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    [EN] The effect of the application of a pre-osmotic treatment to obtain hot air dried cocona(Solanum sessiliofurum Dunal) chips was studied. The drying kinetics and the optical andmechanical properties of cocona chips obtained by the combined method of osmotic dehy-dration and hot air drying (OD + HAD) and by only hot air drying (HAD) were compared.Samples were dried by hot air at 60◦C. For the combined method, they were pre-dried toa moisture content of 75 gwater/100 g, immersed in a 55◦Brix sucrose solution at 25◦C for48 min. The pre-osmodehydration applied did not influence the subsequent hot air dryingkinetics, resulting in a final product with 0.055 ± 0.005 gwater/gcocona.The optical properties ofOD + HAD chips were more favorable, exhibiting a smaller color change with respect to thefresh fruit (±15 units) than the HAD samples (±23 units). On the other hand, the OD + HADchips presented more fracture peaks than HAD ones, this related with a structure with ahigher degree of crispness, a very desirable property for a chip product.The authors thank the Universidad Politecnica de Valencia for the financial support given throughout the Project ADSIDEO-COOPERACION 2010 "Adaptacion de procesos de secado para favorecer la comercializacion de super frutas de origen colombiano".Agudelo Sterling, CM.; Igual Ramo, M.; Talens Oliag, P.; Martínez Navarrete, N. (2015). Optical and mechanical properties of cocona chips as affected by the drying process. Food and Bioproducts Processing. 95:192-199. doi:10.1016/j.fbp.2015.05.009S1921999

    The influence of the polar head-group of synthetic cationic lipids on the transfection efficiency mediated by niosomes in rat retina and brain

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    The development of novel non-viral delivery vehicles is essential in the search of more efficient strategies for retina and brain diseases. Herein, optimized niosome formulations prepared by oil-in water (o/w) and film-hydration techniques were characterized in terms of size, PDI, zeta potential, morphology and stability. Three ionizable glycerol-based cationic lipids containing a primary amine group (lipid 1), a triglycine group (lipid 2) and a dimethylamino ethyl pendent group (lipid 3) as polar head-groups were part of such niosomes. Upon the addition of pCMS-EGFP plasmid, nioplexes were obtained at different cationic lipid/DNA ratios (w/w). The resultant nioplexes were further physicochemically characterized and evaluated to condense, release and protect the DNA against enzymatic digestion. In vitro experiments were performed to evaluate transfection efficiency and cell viability in HEK-293, ARPE-19 and PECC cells. Interestingly, niosome formulations based on lipid 3 showed better transfection efficiencies in ARPE-19 and PECC cells than the rest of cationic lipids showed in this study. In vivo experiments in rat retina after intravitreal and subretinal injections together with in rat brain after cerebral cortex administration showed promising transfection efficiencies when niosome formulations based on lipid 3 were used. These results provide new insights for the development of non-viral vectors based on cationic lipids and their applications for efficient delivery of genetic material to the retina and brain. © 2015 Elsevier Ltd.This project was partially supported by the University of the Basque Country UPV/EHU (UFI 11/32), the National Council of Science and Technology (CONACYT), Mexico, Reg. # 217101, the Spanish Ministry of Education (Grant CTQ2010-20541, CTQ2010- 14897), the Basque Government (Department of Education, University and Research, predoctoral BFI-2011-2226 grant) and by Spanish grants MAT2012-39290-C02-01 and IPT-2012-0574- 300000. Technical and human support provided by SGIker (UPV/ EHU) is gratefully acknowledged. Authors also wish to thank the intellectual and technical assistance from the ICTS “NANBIOSIS”, more specifically by the Drug Formulation Unit (U10) of the CIBER in Bioengineering, Biomaterials & Nanomedicine (CIBER-BBN) at the University of Basque Country (UPV/EHU).Peer reviewe

    Physicochemical properties and structural characteristics of whole grain Oryza sativa L. with different treatments

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    [EN] Physicochemical properties and structural characteristics of whole rice flours with different treatments (soaking, germination and extrusion cooking) were studied. Water solubility, water absorption, crystallinity, adsorption isotherms (BET and GAB models), and glass transition temperature of the samples were determined. Water solubility and water absorption were enhanced by extrusion cooking process (3.17 4.98 vs. 24.1 53.76 g/100 g and 2.77 3.05 vs. 4.46 7.04 ml/g, respectively), but crystallinity was decreased (30 33 vs. 4 16%). Adsorption isotherms showed that extruded samples exhibited higher equilibrium moisture content as compared with their corresponding non-extruded samples (5.0 19.2 vs. 4.0 16.1 g water/g solids). There were no changes in glass transition temperature values in the studied moisture range (3.8 16 g/100 g). These results allow the correct use of whole rice flours with different treatments in foods and also contributed to the knowledge of stabilization of the productsThe author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was partially financed by ANPCYT (PICT 1105) and ERASMUS MUNDUS ACTION 2 ARCOIRIS Fellowship.Albarracin, M.; Talens Oliag, P.; Martínez Navarrete, N.; González, RJ.; Drago, SR. (2016). Physicochemical properties and structural characteristics of whole grain Oryza sativa L. with different treatments. Food Science and Technology International. 22(4):1-10. doi:10.1177/1082013215600078S110224Albarracín, M., José González, R., & Drago, S. R. (2015). Soaking and extrusion effects on physicochemical parameters, phytic acid, nutrient content and mineral bio-accessibility of whole rice grain. International Journal of Food Sciences and Nutrition, 66(2), 210-215. doi:10.3109/09637486.2014.986070Björck, I., & Asp, N.-G. (1983). The effects of extrusion cooking on nutritional value — A literature review. Journal of Food Engineering, 2(4), 281-308. doi:10.1016/0260-8774(83)90016-xBrunauer, S., Deming, L. S., Deming, W. E., & Teller, E. (1940). On a Theory of the van der Waals Adsorption of Gases. Journal of the American Chemical Society, 62(7), 1723-1732. doi:10.1021/ja01864a025Donkor, O. N., Stojanovska, L., Ginn, P., Ashton, J., & Vasiljevic, T. (2012). Germinated grains – Sources of bioactive compounds. Food Chemistry, 135(3), 950-959. doi:10.1016/j.foodchem.2012.05.058Gonzalez, R. J., De Greef, D. M., Torres, R. L., Borras, F. S., & Robutti, J. (2004). Effects of endosperm hardness and extrusion temperature on properties of products obtained with grits from two commercial maize cultivars. LWT - Food Science and Technology, 37(2), 193-198. doi:10.1016/j.lwt.2003.07.004Gonzalez, R., Drago, S., Torres, R., & De Greef, D. (2013). Extrusion Cooking of Cereal-Based Products. Contemporary Food Engineering. doi:10.1201/b15246-13González, R. J., Pastor Cavada, E., Vioque Peña, J., Torres, R. L., De Greef, D. M., & Drago, S. R. (2013). Extrusion Conditions and Amylose Content Affect Physicochemical Properties of Extrudates Obtained from Brown Rice Grains. International Journal of Food Science, 2013, 1-8. doi:10.1155/2013/584148Herawat, H., Kusnandar, F., Adawiyah, D. R., Budijanto, S., & Rahman, M. S. (2014). Thermal characteristics and state diagram of extruded instant artificial rice. Thermochimica Acta, 593, 50-57. doi:10.1016/j.tca.2014.08.017Jones, J. M., & Engleson, J. (2010). Whole Grains: Benefits and Challenges. Annual Review of Food Science and Technology, 1(1), 19-40. doi:10.1146/annurev.food.112408.132746Kim, H. Y., Hwang, I. G., Kim, T. M., Woo, K. S., Park, D. S., Kim, J. H., … Jeong, H. S. (2012). Chemical and functional components in different parts of rough rice (Oryza sativa L.) before and after germination. Food Chemistry, 134(1), 288-293. doi:10.1016/j.foodchem.2012.02.138Lowry, R. R., & Tinsley, I. J. (1976). Rapid colorimetric determination of free fatty acids. Journal of the American Oil Chemists’ Society, 53(7), 470-472. doi:10.1007/bf02636814Matveev, Y. (2000). The plasticizing effect of water on proteins, polysaccharides and their mixtures. Glassy state of biopolymers, food and seeds. Food Hydrocolloids, 14(5), 425-437. doi:10.1016/s0268-005x(00)00020-5Perdon, A., Siebenmorgen, T. J., & Mauromoustakos, A. (2000). Glassy State Transition and Rice Drying: Development of a Brown Rice State Diagram. Cereal Chemistry Journal, 77(6), 708-713. doi:10.1094/cchem.2000.77.6.708ROOS, Y., & KAREL, M. (1991). Plasticizing Effect of Water on Thermal Behavior and Crystallization of Amorphous Food Models. Journal of Food Science, 56(1), 38-43. doi:10.1111/j.1365-2621.1991.tb07970.xRuiz-Ruiz, J., Martínez-Ayala, A., Drago, S., González, R., Betancur-Ancona, D., & Chel-Guerrero, L. (2008). Extrusion of a hard-to-cook bean (Phaseolus vulgaris L.) and quality protein maize (Zea mays L.) flour blend. LWT - Food Science and Technology, 41(10), 1799-1807. doi:10.1016/j.lwt.2008.01.005SIU, G. M., & DRAPER, H. H. (1978). A SURVEY OF THE MALONALDEHYDE CONTENT OF RETAIL MEATS AND FISH. Journal of Food Science, 43(4), 1147-1149. doi:10.1111/j.1365-2621.1978.tb15256.xSun, Z., Yang, W., Siebenmorgen, T., Stelwagen, A., & Cnossen, A. (2002). Thermomechanical Transitions of Rice Kernels. Cereal Chemistry Journal, 79(3), 349-353. doi:10.1094/cchem.2002.79.3.349Timmermann, E. O. (2003). Multilayer sorption parameters: BET or GAB values? Colloids and Surfaces A: Physicochemical and Engineering Aspects, 220(1-3), 235-260. doi:10.1016/s0927-7757(03)00059-1Tovar, J., Bjoerck, I. M., & Asp, N. G. (1990). Starch content and .alpha.-amylolysis rate in precooked legume flours. Journal of Agricultural and Food Chemistry, 38(9), 1818-1823. doi:10.1021/jf00099a00

    Development of minimal fermentation media supplementation for ethanol production using two Saccharomyces cerevisiae strains

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    Ethanol production by fermentation is strongly dependent on media composition. Specific nutrients, such as trace elements, vitamins and nitrogen will affect the physiological state and, consequently, the fermentation performance of the micro-organism employed. The purpose of this study has been to assess the highest ethanol production by a minimal medium, instead of the more complex nutrients supplementation used during alcoholic fermentation. All fermentation tests were carried out using a microwell plate reader to monitor the processes. Two Saccharomyces cerevisiae strains (NCYC 2826 and NCYC 3445) were tested using three nitrogen sources, supplied with different vitamin and salts. The results show that solutions made of urea phosphate, KCl, MgSO4·7H2O, Ca-panthothenate, biotin allowed an ethanol yield of 22.9 and 23.4 g/L for strain NCYC 2826 and NCYC 3445, respectively, representing 90 and 92% of the theoretical yield. All tests were carried out using glucose as common reference carbon source

    Physicochemical and sensorial properties of grapefruit jams as affected by processing

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    Jam is an effective and tasty way of preserving fruit. Jam processing procedures as well as storage conditions and duration are important factors for jam quality. Traditional jam processing involves the application of severe thermal treatments that imply undesirable changes in the product quality characteristics such as colour, texture, flavour and nutritional and functional value. In this work, osmotic dehydration (OD) and/or microwave energy (MW) was proven as adequate to obtain jam with the typical characteristics of water content, degree Brix, pH and water activity of jam obtained by conventional thermal heating. The sensory evaluation carried out to compare the product showed that samples submitted to more intense heating treatments (conventional or MW) had significantly higher scores in colour saturation, brightness, grapefruit taste and extensibility than OD or OD+MW ones. As deduced from the obtained results, OD treatment prevents grapefruit colour changes, and mild MW heating contributes to increase the consistency and decrease the extensibility of the obtained jam. In this way, OD+MW jam was preferred by assessors mainly due to its higher consistency. The sample obtained by this procedure was stable during storage.The authors would like to thank the Ministerio de Educacion y Ciencia for the financial support given throughout the Project AGL 2005-05994. The language revision of this paper was funded by the Universidad Politecnica de Valencia, Spain.Igual Ramo, M.; García Martínez, EM.; Camacho Vidal, MM.; Martínez Navarrete, N. (2013). Physicochemical and sensorial properties of grapefruit jams as affected by processing. Food and Bioprocess Technology. 6(1):177-185. https://doi.org/10.1007/s11947-011-0696-2S17718561AENOR (2009). Sensory analysis. Methodology. Paired comparison test. UNE-EN-ISO 5495.AOAC. (2000). 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    Lead Optimization of 3,5-Disubstituted-7-Azaindoles for the Treatment of Human African Trypanosomiasis.

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    Neglected tropical diseases such as human African trypanosomiasis (HAT) are prevalent primarily in tropical climates and among populations living in poverty. Historically, the lack of economic incentive to develop new treatments for these diseases has meant that existing therapeutics have serious shortcomings in terms of safety, efficacy, and administration, and better therapeutics are needed. We now report a series of 3,5-disubstituted-7-azaindoles identified as growth inhibitors of Trypanosoma brucei, the parasite that causes HAT, through a high-throughput screen. We describe the hit-to-lead optimization of this series and the development and preclinical investigation of 29d, a potent antitrypanosomal compound with promising pharmacokinetic (PK) parameters. This compound was ultimately not progressed beyond in vivo PK studies due to its inability to penetrate the blood-brain barrier (BBB), critical for stage 2 HAT treatments.The authors acknowledge funding from the National Institute of Allergy and Infectious Diseases (M.P.P. and M.N., R01AI114685; M.P.P., 1R21AI127594, R01AI124046; C.R.C., R21AI126296; https://www.niaid.nih.gov/), the Spanish Ministerio de Economí a, Industria y Competitividad (M.N., SAF2015-71444-P; D.G.-P., SAF2016-79957-R; http://www.mineco.gob.es), Subdireccion General de Redes ́ y Centros de Investigacion Cooperativa (RICET, https://www.ricet.es/) (M.N., RD16/0027/0019; D.G.P., RD16/ 0027/0014), and RTI2018-097210-B-I00 (MINCIU-FEDER) to F.G. An ACS MEDI Predoctoral Fellowship for D.M.K. is gratefully acknowledged, as is support from the National Science Foundation for K.F. (CHE-1262734). We thank AstraZeneca, Charles River Laboratories, and GlaxoSmithKline for the provision of the in vitro ADME and physicochemical properties data. The use of JChem/ChemAxon software is acknowledged
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