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981.
Diego F. Acevedo Evelina Frontera Martín F. Broglia Frank Mücklich María C. Miras César A. Barbero 《Advanced Engineering Materials》2011,13(5):405-410
Large areas of polypyrrole (PPy) thin films deposited onto inert polymeric substrates are structured by direct laser interference patterning (DLIP). Several square millimeter areas could be produced with one single (10 ns) pulse, at room temperature and atmospheric pressure. Nanometric arrays of lines (>600 nm) or grids of PPy deposited on dielectric polymers polypropilene or polypirrol (PP or PE) are fabricated by DLIP at 355 nm. The period of the lines structures, measured by white light interferometry (WLI), is 3.5 µm. Regular structures are analyzed using scanning electron microscope (SEM) and a focus ion beam (FIB) tomography. It is shown that only the PPy film is structured while the PP or PE substrate remains unaltered. Fourier transform infrared spectroscopy (FTIR) and UV‐vis spectroscopy, permit to ensure that PPy chemical structure remains unaltered after the structuration process. The width of PPy lines can be tailored by controlling the fluence of the laser beam. Contact angle measurement shows that the wettability is affected by the structuring, making the surface more hydrophobic. The structuring technique seems to be suitable for the fabrication of PPy regular structures over various substrates. 相似文献
982.
Sáez P Peña E Doblaré M Martínez MÁ 《IEEE transactions on bio-medical engineering》2011,58(12):3500-3503
Evolutionary processes in biological tissue, such as adaptation or remodeling, represent an enterprising area of research. In this paper, we present a multiscale model for the remodeling of fibered structures, such as bundles of collagen fibrils. With this aim, we introduce a von Mises statistical distribution function to account for the directional dispersion of the fibrils, and we remodel the underlying fibrils by changing their orientation. To numerically compute this process, we make use of the microsphere approach, which provides a useful multiscale tool for homogenizing the microstructure behavior, related to the fibrils of the bundle, in the macroscale of the problem. The results show how the fibrils respond to the stimulus by reorientation of their structure. This process leads to a stiffer material eventually reaching a stationary state. These results are in agreement with those reported in the literature, and they characterize the adaptation of biological tissue to external stimuli. 相似文献
983.
Murphy K van Ginneken B Reinhardt JM Kabus S Ding K Deng X Cao K Du K Christensen GE Garcia V Vercauteren T Ayache N Commowick O Malandain G Glocker B Paragios N Navab N Gorbunova V Sporring J de Bruijne M Han X Heinrich MP Schnabel JA Jenkinson M Lorenz C Modat M McClelland JR Ourselin S Muenzing SE Viergever MA De Nigris D Collins DL Arbel T Peroni M Li R Sharp GC Schmidt-Richberg A Ehrhardt J Werner R Smeets D Loeckx D Song G Tustison N Avants B Gee JC Staring M Klein S Stoel BC Urschler M 《IEEE transactions on medical imaging》2011,30(11):1901-1920
EMPIRE10 (Evaluation of Methods for Pulmonary Image REgistration 2010) is a public platform for fair and meaningful comparison of registration algorithms which are applied to a database of intrapatient thoracic CT image pairs. Evaluation of nonrigid registration techniques is a nontrivial task. This is compounded by the fact that researchers typically test only on their own data, which varies widely. For this reason, reliable assessment and comparison of different registration algorithms has been virtually impossible in the past. In this work we present the results of the launch phase of EMPIRE10, which comprised the comprehensive evaluation and comparison of 20 individual algorithms from leading academic and industrial research groups. All algorithms are applied to the same set of 30 thoracic CT pairs. Algorithm settings and parameters are chosen by researchers expert in the configuration of their own method and the evaluation is independent, using the same criteria for all participants. All results are published on the EMPIRE10 website (http://empire10.isi.uu.nl). The challenge remains ongoing and open to new participants. Full results from 24 algorithms have been published at the time of writing. This paper details the organization of the challenge, the data and evaluation methods and the outcome of the initial launch with 20 algorithms. The gain in knowledge and future work are discussed. 相似文献
984.
Joaquín Giner Esteban Bailo Vicente Gimeno Olga Martín-Belloso 《European Food Research and Technology》2005,221(3-4):255-264
The inactivation of pectinesterase (PE) in a commercial enzyme formulation (CEF) under pulsed electric fields (PEF) was studied. Samples of an aqueous solution of the CEF were exposed to exponential waveform pulses for up to 16 ms at electric field intensities ranging from 5 to 24 kV cm–1. Pulses were delivered in monopolar mode. The observed inactivation of the enzyme was described by several kinetics and regarding the input of electrical energy density (Q) models using Bayesian non-linear regression. Posterior distributions of the characteristic parameters for each kinetic model (based on the Hülsheger or the Weibull equation) and each Q model (based on exponential decay or the Weibull equation) were obtained. Kinetics models based on the Weibull equation showed better goodness and accuracy than the other models. 相似文献
985.
Rodrı X Guez MA Garcı X A T González I Asensio L Mayoral B López-Calleja I Hernández PE Martı X N R 《Meat science》2003,65(4):1257-1263
Polymerase chain reaction amplification of a conserved region of the -actin gene has been used for the specific identification of goose (Anser anser) and mule duck (Anas platyrhynchos×Cairina moschata) foie gras. Universal primers were used for the amplification of a DNA fragment containing three introns and four exons of the -actin gene in goose and mule duck. Sequence analysis of the amplified fragments was necessary for the design of forward species-specific primers in the goose and mule duck -actin genes. The use of species-specific forward primers, together with a reverse universal primer, produced amplicons of different length, allowing clear identification of goose and mule duck foie gras samples. Analysis of experimental mixtures demonstrated that 1% of duck can be easily detected in goose foie gras using the PCR method developed here. This genetic marker can be very useful for the accurate identification of these two species in foie gras products. 相似文献
986.
The aim of this research was to study and model the kinetics of the hot-air drying of Aloe vera (Aloe barbadensis Miller) and to evaluate the influence of temperature on the kinetic parameters for the proposed models. A convective dryer was used at 50, 60, 70, 80 and 90 °C with an air flow of 2.0±0.2 m/s. The sorption isotherm of the fresh product was mathematically described by the Guggenheim, Anderson and de Boer (GAB) model, giving as a result monolayer moisture of 0.20 g water/g d.b. The mathematical models evaluated in the kinetic research included five empirical equations (Newton, Henderson-Pabis, Page, modified Page and Fick's diffusional model). The fit quality of the proposed models was evaluated by using the linear regression coefficient (r2), sum square error (SSE), root mean square error (RMSE) and Chi-square statistic (χ2). The diffusivity coefficient increased with the temperature from 5.30 to 17.73×10−10 m2/s, for a range of temperatures between 50 and 90 °C, with an estimated activation energy of 30.37 kJ/mol. When comparing the experimental moisture values with those estimated by the proposed models, the modified Page model provided the best to fit of the data, showing that this equation correctly simulates the Aloe vera drying process and represents an excellent tool for estimating its drying time. 相似文献
987.
Effects of substrate, water activity, and temperature on growth and verrucosidin production by Penicillium polonicum isolated from dry-cured ham 总被引:1,自引:0,他引:1
Núñez F Díaz MC Rodríguez M Aranda E Martín A Asensio MA 《Journal of food protection》2000,63(2):231-236
Penicillium polonicum, a common mold on dry-cured meat products, is able to produce verrucosidin, a potent neurotoxin. The ability of P. polonicum isolated from dry-cured ham to grow and produce verrucosidin from 4 to 40 degrees C at water activities (a(w)) of 0.99, 0.97, and 0.95 on malt extract agar (MEA) and a medium made up with meat extract, peptone, and agar (MPA) was evaluated. Verrucosidin was quantified by high-pressure liquid chromatography and mass spectrometry. P. polonicum was able to grow on MEA and MPA at all the a(w) values tested from 4 to 37 degrees C but not at 40 degrees C. The optimal environmental conditions for growth were 20 degrees C, 0.99 a(w) on MEA and 20 to 25 degrees C, 0.97 a(w) on MPA, but the highest amount of verrucosidin was obtained at 25 degrees C, 0.99 a(w) in both media. No direct correlation between extension of mold growth and verrucosidin production was found. Temperature appears to be the most important factor ruling mycelial growth, whereas verrucosidin accumulation is mostly influenced by a(w). However, analysis of variance of the data showed that there was a complex interaction among all the environmental factors (medium, temperature, and a(w)) that significantly (P < 0.0001) affected growth and verrucosidin production. The reduction of a(w) to intermediates values of 0.95 has a stronger effect on growth on MEA than on MPA. Given that the meat-based medium proved to be an appropriate substrate for the biosynthesis of verrucosidin by P. polonicum, the ability of this mold to produce the toxin on meat products should be established. 相似文献
988.
Enrique M Marcos JF Yuste M Martínez M Vallés S Manzanares P 《International journal of food microbiology》2007,118(3):318-325
The antimicrobial action of selected short synthetic peptides against wine spoilage yeasts such as Cryptococcus albidus, Dekkera bruxellensis, Pichia membranifaciens, Saccharomyces cerevisiae, Zygosaccharomyces bailii and Zygosaccharomyces bisporus has been examined. Peptides analyzed include nine sequence-related antifungal hexapeptides (PAFs) previously developed by a combinatorial approach, and two representative lactoferricin B (LfcinB)-derived peptides. Different peptides had distinct activity profiles. In vitro assays identified the peptides PAF26, PAF36, and LfcinB(17-31), as having growth inhibitory properties towards several of the yeasts at low micromolar concentrations. Z. bailii and Z. bisporus were the most sensitive yeasts. In addition to their fungistatic activity, the three peptides showed fungicidal properties towards Z. bailii, Z. bisporus, and S. cerevisiae in laboratory growth medium. Remarkably, only LfcinB(17-31) against Z. bisporus had inhibitory and fungicidal properties in wine at the concentrations assayed, showing that the antimicrobial action of each peptide is dependent on both the food matrix and the target micro-organism. Lack of fungicidal activity of peptides against Z. bailii in wine is related to the presence of salt ions other than divalent cations. On the contrary, fungicidal activity of LfcinB(17-31) towards Z. bisporus was not significantly affected by wine salts. Our data identify a bioactive peptide from natural origin with potential use against the food spoilage yeast Z. bisporus, and indicate that the application of antimicrobial peptides in wine preservation deserves further investigation. 相似文献
989.
Resveratrol is a phenolic compound of the stilbene family present in wines and various parts of the grape, including the skin. In this study, the antioxidant and prooxidant activities of resveratrol were compared with other antioxidants (butylated hydroxytoluene [BHT], butylated hydroxyacetone [BHA], phenol, propyl gallate [PG], sodium tripolyphosphate [TPP], alpha-tocopherol, and vanillin) widely used in foods. The ability of these compounds to inhibit lipid peroxidation was as follows: BHA > resveratrol > PG > tripolyphosphate > vanillin > phenol > BHT > alpha-tocopherol, the first three inhibiting the peroxidation in a concentration-dependent manner. The order of OH* scavenger activity of the tested compounds was BHA > TPP > BHT. Resveratrol and vanillin produced between 10 to 7% and 16 to 10% inhibition of the deoxyribose attack, respectively, but they do not scavenge OH*. Neither the resveratrol analyzed nor PG or the rest of compounds reacted with H202 and must be considered inefficient in catalyzing any subsequent oxidation. The ability to scavenge HOCI was, in decreasing order, PG > resveratrol > alpha-tocopherol > phenol. The other compounds did not scavenge HOCl. 相似文献
990.
Oligosaccharide profiles in yeasted and unyeasted wheat sourdoughs inoculated withLactobacillus plantarum have been investigated. A surface response design (central composite design structure) has been used to study the effect of flour extraction rate (0.54, 1.11 and 1.68% ash content), dough yield (160, 200, and 240) and fermentation temperature (25, 30 and 35°C). Unfermented and 20 h fermented doughs were evaluated. Multivariate data analysis was used to analyse the data. Unfermented doughs contained variable amounts of glucose, fructose and maltose, but oligosaccharides with a degree of polymerization (DP) over 3 were not detected. The greatest levels of monosaccharides corresponded to yeasted sourdoughs from brown flours prepared at 30 and 35°C. Factor analysis of fermented sourdoughs showed three factors explaining 83% variability of the data. The first factor (43% variance explained) was directly related to oligosaccharides with a DP above 5, and inversely related to maltose content. Factor two (27%) was related to DP 3 and DP 4, and the third factor (16%) to glucose and fructose levels. The greatest quantities of maltose corresponded to white unyeasted sourdoughs, and the highest amounts of monosaccharides corresponded to brown unyeasted samples. On the other hand, yeasted sourdoughs contained higher amounts of oligosaccharides with DP 3 to DP 5. Samples of white flour, low consistency, yeasted and fermented at ≧30°C showed the biggest content of DP 6 and DP 7. 相似文献