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491.
A method was developed to differentiate between Bacillus cereus, Bacillus mycoides and Bacillus thuringiensis using the polymerase chain reaction combined with a restriction endonuclease (PCR-RE) technique. This fast and simple protocol, applied to pure culture strains, was developed using the gyrB DNA sequence, as previously proposed by other authors. Strains from international collections were used to optimize the method which was then applied to the identification of strains isolated from food samples. Amplifications were specific for the B. cereus group. Only Staphylococcus aureus gave the same size PCR product, but it was easily differentiated from strains in the B. cereus group by using restriction analysis, based on digestion with the RsaI, Sau3AI and EcoRI endonucleases. Specific amplifications and good differentiations were obtained using pure strains, suggesting the possibility of using the method described to identify the B. cereus group directly in food samples.  相似文献   
492.
Dittany (Origanus dictamnus L.) has been compared with rosemary (Rosmarinus officinalis L.) as an antioxidant in pre-cooked meat balls made from chicken breast and added 0.50% salt during chill storage for up to ten days packed in atmospheric air. For an addition of 0.10% of dried leaves, dittany yielded protection of the product against oxidation a little less efficiently but comparable to dried rosemary added at the same concentration. For addition of 0.050%, dittany was less efficient than rosemary, while dittany at this concentration protected vitamin E against degradation in the product during storage even better than rosemary.  相似文献   
493.
The influence of a Lactobacillus plantarum (B4) on the growth of Staphylococcus aureus (Sa4) was verified by impedometric methods in a suitable model reproducing the characteristics of fresh vegetables. The inoculum size of the single strains and their growth temperature were varied according to a Central Composite Design. The results obtained via statistical analysis showed that the temperature affected the growth of both S. aureus and L. plantarum strains. The pathogenic strain, independently of its inoculum size, was inhibited by L. plantarum at all the tested temperatures. A proper combination of specific lactic acid bacteria and storage temperature should improve the safety of the vegetable products.  相似文献   
494.
The research evidences the importance of linking chemical and sensory data for the wine characterization; in particular, the Italian white wine made from Inzolia grapes has been considered. Inzolia is one of the most widespread native white grapes in Sicily (Italy), and wine samples from two different areas (Monreale and Sambuca di Sicilia) have been analyzed. A headspace solid-phase microextraction/gas chromatography–mass spectroscopy method has been developed, and 56 volatile components, esters, fatty acids, alcohols, and terpenes have been identified; the method allows also the quantification of the main components, namely, ethyl octanoate (banana, fruit, fat) (257.2–541.6 mg/l) and ethyl decanoate (fruity, oily, floral; 171.8–272.0 mg/l). A good repeatability in terms of retention times and peak areas resulted. Sensory analysis was performed by ten trained judges that evaluated eight attributes: two referring to appearance (yellow color and yellow reflex), four referring to aroma (fruity, banana, ripened apple, and floral), and two referring to oral perception (acid and pungent). The volatile constituents and the aroma sensory attributes were in agreement.  相似文献   
495.
    
The photo‐oxidation of lipids has significant effects on the quality of edible oils. The oxidation of oils and fats can begin due to the action of external energy sources such as light. Studies showed that the rate of photo‐oxidation of the oil depends on the light transmission of the packaging, the product characteristics and the O2 barrier of the packaging. The UV absorber 2‐(2′‐hydroxy‐3′‐tert‐butyl‐5′‐methylphenyl)‐5‐chlorobenzotriazole (Tinuvin 326?) has been used in PET bottles for oil, making possible the reduction of the photo‐oxidation rates. This additive was approved recently by the European Union and included in the Positive List of Directive 2001/62/EC, with a limit of specific migration. This additive is also approved by the Mercosur legislation; nevertheless its restriction of use is being reviewed in Brazil. This study had the objectives of evaluating the efficiency of the additive through the determination of the light barrier properties of PET bottles with various levels of Tinuvin 326? and of verifying its suitability for use in direct contact with foods. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
496.
    
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497.
    
This article examines whether participation in a collaborative planning process leads to change in attitudes and behaviours for process participants. This case examines the five-year impact on stakeholders from a Californian participatory process. In this case (1) transformative learning occurred during the process; (2) learning was sustained over time; (3) few participants reported long-term changes in their professional practices and personal lives; and (4) the organisation that convened the process provided no support to participants to act on what they learned via their participation. The case demonstrates that, if planners expect participants to take action based on process learning, continuing support is necessary.  相似文献   
498.
    
Frequent hemodialysis is associated with increased vascular access adverse events. We hypothesized that bacteremia would be more frequent in patients with central venous catheter (CVC) than arteriovenous fistula or arteriovenous graft (AVF/AVG) in nocturnal home hemodialysis (NHHD). We reviewed blood culture reports and concurrent clinical data for a cohort of one hundred eighty‐seven NHHD patients between January 1, 2006 and June 30, 2012. The primary outcome was time to first bacteremia, technique failure, or death after commencing NHHD. Types of bacteremia and clinical consequences were analyzed. Analyses were adjusted for a priori defined confounders. One hundred eighty‐seven patients were included with a total follow up of six hundred five patient years. Initial vascular access was AVF in seventy‐eight (42%) patients, AVG in eleven (6%) patients, and CVC in ninety‐eight (52%) patients. A total of 79.3% of patients with a CVC reached the composite endpoint of bacteremia, technique failure, or death in the study period; 44.5% of patients with an AVF or AVG reached this composite endpoint. Adjusted time to first bacteremia, technique failure, or death was significantly shorter in patients with initial CVC access (hazard ratio 2.42, 95% confidence interval 1.50–3.90, p < 0.001). Risk factors for bacteremia were comorbid status quantified by the Charlson Comorbidity Index (p < 0.001) and diabetes (p < 0.001). Coagulase negative staphylococcus was the commonest organism cultured accounting for 51.4% bacteremias. The second commonest organism was staphylococcus aureus (20.3% bacteremias). Patients undergoing NHHD with a CVC have a shorter duration to first infection, technique failure, or death than those with permanent vascular access.  相似文献   
499.
    
The effect of addition of propylene copolymer, produced by metallocene catalysts, on the mechanical, rheological, and morphological properties of blends based on poly(propylene) (PP) and ethylene–1‐octene copolymer (EOC) was evaluated. It was observed that the addition of 2 wt % propylene–1‐octene copolymer (POC) improved the impact strength of the EOC/PP blends. The rheological analysis indicated that the addition of propylene copolymer produced materials with improved processability. Thermal and morphological analysis showed that the POC acts as a compatibilizer on the EOC/PP blends. © 2003 Wiley Periodicals, J Appl Polym Sci 89: 1690–1695, 2003  相似文献   
500.
    
Silk hydrogels are interesting materials to be used as matrix in controlled drug delivery devices. However, methods to accelerate fibroin gelation and allow the drug incorporation during the hydrogel preparation are needed in literature. In this article we report the preparation of silk fibroin hydrogels with addition of several contents of ethanol, used to accelerate fibroin gelation kinetics, and we also evaluate the potential of these hydrogels to be used as matrices for drug delivery. Chemical and conformational properties did not change despite the amount of ethanol incorporated in the hydrogel. Hydrogels containing diclofenac sodium dissolved in ethanol showed a faster initial release of the drug than hydrogels with the drug dissolved in water but equilibrium was reached later. This indicates a more sustained drug delivery from hydrogels in which the model drug was dissolved in ethanol. Fibroin hydrogels confirm their promising use as biopolymeric matrices for controlled drug release. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41802.  相似文献   
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