478 research outputs found
Water content-water activity-glass transition temperature relationships of spray-dried borojó as related to changes in color and mechanical properties
The water content-water activity-glass transition temperature relationships of commercial spray-dried borojó powder, with and without maltodextrin, have been studied as related to changes in color and mechanical properties. The GAB and Gordon and Taylor models were well fitted to the sorption and glass transition data, respectively. The Boltzman equation adequately described the evolution of the mechanical parameter characterized in the samples with the difference between the experimental temperature and the glass transition temperature (T g) of the sample. The color of the samples showed a sigmoid change with water activity. The changes in the mechanical properties of borojó powder related to collapse development started when the sample moved to the rubbery state and began to be significant at about 10 °C above T g. The increase in the molecular mobility from this point on also favors browning reactions. Maltodextrin presence slows the caking kinetics but induces color changes to spray-dried borojó powderThe authors thank the Ministerio de Ciencia e Innovacion and the Fondo Europeo de Desarrollo regional (FEDER) for the financial support throughout Project AGL2010-22176 and the Project UTCH-NUFFIC (NPT/COL/073) for the grant given to LH Mosquera.Mosquera, LH.; Moraga Ballesteros, G.; Fernández De Córdoba Castellá, PJ.; Martínez Navarrete, N. (2011). Water content-water activity-glass transition temperature relationships of spray-dried borojó as related to changes in color and mechanical properties. Food Biophysics. 6(3):397-406. https://doi.org/10.1007/s11483-011-9215-2S39740663L.H. Mosquera, G. Moraga, N. Martínez-Navarrete, J Food Eng 9, 72 (2010). doi: 10.1016/j.jfoodeng.2009.09.017V. Truong, B.R. Bhandari, T. Howe, J Food Eng 71, 55 (2005). doi: 10.1016/j.jfoodeng.2004.10.017B. Bhandari, Glass transition in relation to stickiness during spray drying (Academic Sterling, London, 2001), p. 64Y. Roos, Phase transitions in foods (Academic, New York, 1995), p. 360P. Saragoni, J.M. Aguilera, P. Bouchon, Food Chem 104, 122 (2007). doi: 10.1016/j.foodchem.2007.11.066C.K. Pua, N. Sheikh Abd. Hamid, C.P. Tanm, H. Mirhosseini, R. Abd. Rahman, G. Rusul, J Food Eng 89, 419 (2008). doi: 10.1016/j.jfoodeng.2008.05.023V.R.N. Telis, N. Martínez-Navarrete, LWT Food Sci Technol 43, 744 (2010)L. Greenspan, J Res Natl Inst Stand 81, 89 (1977). IDS: DM875W.E.L. Spiess, W.R. Wolf, in Physical properties of foods, ed by F. Escher, B. Hallstrom, H.S. Mefert, W.E.L. Spiess, G. Woss. (Applied Sci, New York, 1983), p. 65C. Van den Berg, S. Bruin, in Water activity and its estimation in food systems: theoretical aspects, ed by L.B. Rockland, G.T. Stewart (Academic Press, London, 1981), p. 43M. Gordon, J.S. Taylor, J Appl Chem 2, 493 (1952). doi: 10.1002/jctb.5010020901GV.R.N. Telis, N. Martínez-Navarrete, Food Biophys 4, 83 (2009). doi: 10.1007/s11483-003-9104-0G. Moraga, N. Martínez-Navarrete, A. Chiralt, J Food Eng 62, 315 (2004). doi: 10.1016/S0260-8774(03)00245-0C.I. Beristain, E. Azuara, E.J. Vernon-Carter, J Food Sci 67, 211 (2002). IDS: 522JPB.R. Bandhari, R.W. Hartel, in Encapsulated and food powder, ed by C. Onwulata, R.P. Konstance (Marcel Dekker, New York, 2005), p. 216N. William, Estadística para Ingenieros y Científicos (MacGraw-Hill, Mexico, 2006), p. 120A.L. Gabas, V.R.N. Telis, P.J.A. Sobral, J. Telis-Romero, J Food Eng 82, 246 (2007). doi: 10.1016/j.jfoodeng.2007.02.029M.A. Silva, P.J.A. Sobral, T.G. Kieckbusch, J Food Eng 77, 426 (2006). doi: 10.1016/j.jfoodeng.2005.07.009MdK Haque, Y.H. Ross, Innov Food Sci Emerg Technol 7, 1–2 (2006). doi: 10.1016/j.ifset.2004.12.004J.M. Aguilera, J.M. del Valle, M. Karel, Trends Food Sci Technol 8, 149 (1995). doi: 10.1016/S0924-2244(00)89023H. Levine, L. Slade, Cryoletters 9, 21 (1988). IDS: M1923Y.H. Ross, J Food Eng 24, 339 (1995). doi: 10.1016/0260-8774(95)90050-LG. Barbosa-Canovas, E. Ortega-Rivas, P. Juliano, H. Yan, Food powders: physical properties, processing and functionality (Kluwer Academic/Plenum Publisher, New York, 2005), p. 372K.D. Foster, J.E. Bronlund, A.H.J. Paterson, J Food Eng 77, 997 (2006). doi: 10.1016/j.jfoodeng.2005.08.028E. Venir, M. Munari, A. Tonizzo, E.J. Maltini, Food Eng 81, 27 (2007). doi: 10.1016/j.jfoodeng.2006.10.004N.C. Acevedo, C. Schebor, P. Buera, J Food Eng 77, 1108 (2006). doi: 10.1016/j.jfoodeng.2005.08.045N.C. Acevedo, C. Schebor, P. Buera, Food Chem 108, 900 (2008). doi: 10.1016/j.foodchem.2007.11.057J. Ahmed, U.S. Shivhareb, P. Singhc, Food Chem 84, 605 (2004). doi: 10.1016/S0308-8146(03)00285-1L. Hang-Ing Ling, J. Birch, M. Lim, Int J Food Sci Technol 40, 921 (2005). doi: 10.1111/j.1365-2621.2005.0099
PACIFICO (Océano). Expediciones geográficas (1803). 1:37037036
Graduado. Escala hallada a partir de un meridiano de latitud [= 0,3 cm]Longitud observada por distancias lunaresToponimia sólo en las costasTrazada la línea de derrota, con indicación del día y mes en que se alcanzó cada puntoCopia digital. Madrid : Ministerio de Cultura. Dirección General del Libro, Archivos y Bibliotecas, 201
Circulating epithelial cell as viral infection and tissue origin marker in patients with severe COVID-19
Liquid biopsy (LB) is a minimally invasive procedure that detects biomarkers in body fluids for real-time monitoring of patients. This study developed a new LB approach to analyze Circulating Epithelial Cells (CECs) in Intensive Care Unit (ICU) patients with severe COVID-19 and High-Exposure Negative Population to COVID-19 (HENPC) as the control group. The CECs were characterized by multispectral imaging flow cytometry, and an anti-SARS-CoV-2 Spike S1 protein (ProtS) antibody was used to detect infection. The results showed that CECs were present in most ICU patients (p = 0.0412), and their median number was significantly higher (p = 0.0004) than in controls. CEC clusters were only identified in patients, and high positive ProtS expression was observed in CECs from ICU patients compared to negative controls. In conclusion, LB could be a minimally invasive tool for detecting tissue damage caused by infectious agents and could provide real-time biological information about disease status and evolution. However, further validation in a larger population of patients is needed
Transplantation of Human Induced Pluripotent Stem Cell-Derived Retinal Pigment Epithelium in a Swine Model of Geographic Atrophy
Background: The aim of this study was to test the feasibility and safety of subretinal transplantation of human induced pluripotent stem cell (hiPSC)-derived retinal pigment epithelium (RPE) cells into the healthy margins and within areas of degenerative retina in a swine model of geographic atrophy (GA). Methods: Well-delimited selective outer retinal damage was induced by subretinal injection of NaIO3 into one eye in minipigs (n = 10). Thirty days later, a suspension of hiPSC-derived RPE cells expressing green fluorescent protein was injected into the subretinal space, into the healthy margins, and within areas of degenerative retina. In vivo follow-up was performed by multimodal imaging. Post-mortem retinas were analyzed by immunohistochemistry and histology. Results: In vitro differentiated hiPSC-RPE cells showed a typical epithelial morphology, expressed RPE-related genes, and had phagocytic ability. Engrafted hiPSC-RPE cells were detected in 60% of the eyes, forming mature epithelium in healthy retina extending towards the border of the atrophy. Histological analysis revealed RPE interaction with host photoreceptors in the healthy retina. Engrafted cells in the atrophic zone were found in a patchy distribution but failed to form an epithelial-like layer. Conclusions: These results might support the use of hiPSC-RPE cells to treat atrophic GA by providing a housekeeping function to aid the overwhelmed remnant RPE, which might improve its survival and therefore slow down the progression of GA. Keywords: age-related macular degeneration (AMD); geographic atrophy; pig; animal model; stem cells; iPSC; RPE; retina; regenerative medicine; advanced cell therap
Fibre-optic SPR sensor with a FBG interrogation scheme for readout enhancement
In this work a new configuration of a refractometric sensor for aqueous solutions based on the combination of surface plasmon resonance (SPR) with fibre Bragg gratings (FBG) is presented. Two FBGs are selected having reflection maxima in each side of the plasmon resonance peak. These FBGs enable a different processing scheme for the information provided by the SPR transducer. This improved interrogation method increases the sensitivity and resolution of the sensor compared with those obtained with the usual method of tracking the spectral transmittance minimum and makes the system performance independent of optical source power fluctuations. The experimental results obtained with a double-layer uniform-waist tapered fibre show the feasibility of this approach and its applicability in SPR-based biosensors that must face very exigent measuring conditions
Microglia activation in a model of retinal degeneration and TUDCA neuroprotective effects
Background: Retinitis pigmentosa is a heterogeneous group of inherited neurodegenerative retinal disorders characterized by a progressive peripheral vision loss and night vision difficulties, subsequently leading to central vision impairment. Chronic microglia activation is associated with various neurodegenerative diseases including retinitis pigmentosa. The objective of this study was to quantify microglia activation in the retina of P23H rats, an animal model of retinitis pigmentosa, and to evaluate the therapeutic effects of TUDCA (tauroursodeoxycholic acid), which has been described as a neuroprotective compound. Methods: For this study, homozygous P23H line 3 and Sprague-Dawley (SD) rats were injected weekly with TUDCA (500 mg/kg, ip) or vehicle (saline) from 20 days to 4 months old. Vertical retinal sections and whole-mount retinas were immunostained for specific markers of microglial cells (anti-CD11b, anti-Iba1 and anti-MHC-II). Microglial cell morphology was analyzed and the number of retinal microglial was quantified. Results: Microglial cells in the SD rat retinas were arranged in regular mosaics homogenously distributed within the plexiform and ganglion cell layers. In the P23H rat retina, microglial cells increased in number in all layers compared with control SD rat retinas, preserving the regular mosaic distribution. In addition, a large number of amoeboid CD11b-positive cells were observed in the P23H rat retina, even in the subretinal space. Retinas of TUDCA-treated P23H animals exhibited lower microglial cell number in all layers and absence of microglial cells in the subretinal space. Conclusions: These results report novel TUDCA anti-inflammatory actions, with potential therapeutic implications for neurodegenerative diseases, including retinitis pigmentosa.This research was supported by grants from the Spanish Ministry of Economy and Competitiveness-FEDER (BFU2012-36845), Instituto de Salud Carlos III (RETICS RD12/0034/0010), Organización Nacional de Ciegos Españoles (ONCE), FUNDALUCE, Asociación Retina Asturias and Fundación Jesús de Gangoiti
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