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121.
Characterization of Edible Active Coating Based on Alginate–Thyme Oil–Propionic Acid for the Preservation of Fresh Chicken Breast Fillets
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Silvia Matiacevich Natalia Acevedo Daniel López 《Journal of Food Processing and Preservation》2015,39(6):2792-2801
Chicken meat presents serious problems of processing and storage. Edible coatings are used commercially to improve the shelf life of fresh foods. The aim of this study is to develop an effective antimicrobial edible coating to improve the shelf life and safety of fresh chicken meat. The effect of propionic acid and thyme essential oils as antimicrobial and antioxidant compounds incorporated into alginate‐based edible coating was evaluated. Physical, antimicrobial and sensorial analyses were performed in coated and uncoated samples. Sensorial analysis showed no significant differences between coated and uncoated samples, which do not influence the buying decisions of consumers. The pH of the meat surface, color and sensorial analysis changed during storage time, showing similar behavior between coatings, the principal parameters to determine the shelf life of this product were weight loss and microbiological deterioration, where coatings had different behaviors. The selected coating increased the shelf life by about 33% with the lowest dehydration. 相似文献
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Dina V. Dudina Igor S. Batraev Vladimir Yu. Ulianitsky Natalia V. Bulina Michail A. Korchagin Ivan A. Bataev Alberto Moreira Jorge Jr. 《Journal of Thermal Spray Technology》2014,23(7):1116-1123
In thermally sprayed coatings, nano-sized features of the microstructure may be either inherited from the nanostructured agglomerates of the feedstock powder or form as a result of rapid cooling of molten particles upon deposition. Applying a process of the computer-controlled detonation spraying (CCDS) to Ti3SiC2-Cu composite powders produced by high-energy mechanical milling, we show that both routes are possible depending on the spraying conditions. When the nanostructure of the Ti3SiC2-Cu coating is inherited from the feedstock powder—under very mild conditions of detonation spraying, which exclude melting, so is the phase composition of the coating. In higher-temperature conditions of spraying, a significant fraction of the copper matrix melts and the interaction between Ti3SiC2 and Cu occurs. The TiC x -Cu(Si) coatings that form show crystallites of both phases in the nano-range. In this case, rapid solidification of the molten fraction of the particles is responsible for the formation of the coatings with a nanostructured matrix. Due to the flexibility of the CCDS process, conditions of spraying were found such that a composite coating with very fine crystallites of the Cu(Si) matrix (30 nm) and a hardness of 273 HV could be obtained. 相似文献
124.
Natalia Candu Simona Coman Vasile I. Parvulescu Jamal El Haskouri Pedro Amoros Daniel Beltran 《Topics in Catalysis》2009,52(6-7):571-578
Strong Lewis acid SnTf-MCM-41 and SnTf-UVM-7 catalysts with unimodal and bimodal pore systems were prepared in a two-step synthesis in which the triflic acid (Tf) was incorporated into previously synthesized mesoporous tin-containing silicas. The Sn incorporation inside the pore walls was carried out through the Atrane method. The SnTf-UVM-7 catalysts were prepared by aggregating nanometric mesoporous particles defining a hierarchic textural-type additional pore system. Catalysts with different Si/Sn ratios in the range 21.8–50.8 for SnTf-MCM-41 and 18.4 for SnTf-UVM-7 were found to be efficient catalysts for the acylation of aromatics and heteroaromatics. Under microwave irradiation the reaction was possible even with acetic acid. The selectivity to the desired product (o-hydroxyacetophenone for phenol) or the unfavored three-substituted five ring heterocycles was dramatically increased under these conditions. The process is green, environmentally safe, and heterogeneous. 相似文献
125.
Natalia C. V. MELO Rosilene M. ELIAS Manuel Carlos M. CASTRO Joao E. ROMAO Jr Hugo ABENSUR 《Hemodialysis international. International Symposium on Home Hemodialysis》2009,13(1):38-42
Pruritus is still one of the most common and disturbing symptoms of end-stage renal disease. The objective of this study is to analyze the prevalence of pruritus in hemodialysis patients and the possible factors implicated in its genesis. In a cross-sectional study, 101 patients on hemodialysis at our center were screened for pruritus. The relationship of various factors with pruritus was evaluated. Of the 101 patients included, 31(30.7%) had pruritus at the time of examination. Patients with pruritus were significantly older than those without pruritus (P=0.0027). Pruritus tended to be more prevalent in patients undergoing dialysis 3 times a week than in those undergoing daily dialysis, but the difference did not reach statistical significance (P=0.0854). Lower transferrin saturation levels were found in patients with pruritus than in those without pruritus (P=0.0144). C-reactive protein levels were significantly higher in patients with pruritus than in those without pruritus (P=0.0013). There was no significant difference between the groups in the levels of the other inflammatory biomarkers measured. However, there was a tendency toward a correlation between the levels of α-1-glycoprotein and the intensity of pruritus (P=0.0834). Our results suggest a possible relationship of the inflammatory response upregulation to pruritus. Additionally, there was a positive relationship between pruritus and iron deficiency, possibly associated with inflammatory elevation of hepcidin. A better understanding of the factors implicated in the genesis of pruritus related to end-stage renal disease is crucial in the development of more effective treatments for this symptom. 相似文献
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127.
Eveline Lescrinier Prof. Dr. Natalia Dyubankova Dr. Koen Nauwelaerts Dr. Roger Jones Prof. Dr. Piet Herdewijn Prof. Dr. 《Chembiochem : a European journal of chemical biology》2010,11(10):1404-1412
To what extent small differences in RNA sequences (mutations) can have a profound impact on biology remains an intriguing question. This effect can be studied by using untranslated RNA regions as a model. We have studied the influence of mutations on the structure of an RNA hairpin that occurs in the 3′‐untranslated region (UTR) of Flaviviridae, and is known to have a large impact on the vector dependency of flaviviruses. Three related RNA sequences were studied by NMR spectroscopy. The selected sequences represent each one of the three clusters in the flavivirus genes (mosquito‐borne, tick‐borne, and no‐known‐vector viruses). A new strategy was used to obtain chemical shift signatures of carbonyl atoms in unlabeled uridine nucleobases to characterize their involvement in hydrogen bonding. Clear differences occur in the structures and stacking pattern of the three RNA hairpins. The observed differences cannot be predicted based on sequence analysis. A different biology can be correlated with a different RNA tertiary structure. The underlying biological mechanism, however, remains to be studied. 相似文献
128.
In this study, a novel method of preparation of cryogels based on oxidised dextran (Ox.D) and gelatin (Gel) without sodium borohydride is proposed. The physico-chemical properties of obtained hydrogels were investigated. It was found that the stability of cryogels Ox.D–Gel is significantly depended on pH, and mechanical properties were improved after the freeze drying. The schemes of the reactions between Ox.D and Gel at different steps of the treatment of the material were suggested. According to 1H-NMR data, the Amadori rearrangement occurred under the step of cryogelation. The increase of cross-linking degree through the formation of additional Schiff’s base group was observed as a result of incubation at high humidities or elevated temperature (60 °C). The obtained cryogels can be used as biocompatible and biodegradable scaffolds for proliferation of cells or other biomedical applications. 相似文献
129.
In no science or engineering discipline does it make sense to speak of isolated experiments. The results of a single experiment
cannot be viewed as representative of the underlying reality. Experiment replication is the repetition of an experiment to
double-check its results. Multiple replications of an experiment increase the confidence in its results. Software engineering
has tried its hand at the identical (exact) replication of experiments in the way of the natural sciences (physics, chemistry,
etc.). After numerous attempts over the years, apart from experiments replicated by the same researchers at the same site,
no exact replications have yet been achieved. One key reason for this is the complexity of the software development setting,
which prevents the many experimental conditions from being identically reproduced. This paper reports research into whether
non-exact replications can be of any use. We propose a process aimed at researchers running non-exact replications. Researchers
enacting this process will be able to identify new variables that are possibly having an effect on experiment results. The
process consists of four phases: replication definition and planning, replication operation and analysis, replication interpretation,
and analysis of the replication’s contribution. To test the effectiveness of the proposed process, we have conducted a multiple-case
study, revealing the variables learned from two different replications of an experiment. 相似文献
130.