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121.
Mohamed Ahmed Abdou Nadia M. Awny Azza A. Abou Zeid 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2012,7(3):221-228
In this study three different food preservatives (sodium nitrate, sodium benzoate and sodium sorbate) were used to evaluate their effect on two enterotoxicogenic strains (Bacillus cereus GT1 and Staphylococcus aureus S1). A significant decrease in the viability and production of virulence factors was observed. Yet, obvious tolerance to increasing concentrations (from 1 to 6?g/l) of the three preservatives was recorded reflecting possible resistance mechanisms within the tested strains. The two strains were subjected to increasing doses of gamma radiation (1, 2, 3, 4, 5, 6, 7, 8, 9 and 10?kGy). Obvious correlation was observed between the initial counts of bacterial spores contaminating the products and the required dose for their complete elimination. Whereas the eliminating dose of B. cereus GT1 strain was 10?kGy only 4?kGy was sufficient to suppress the growth and virulence of S. aureus S1, reflecting its sensitivity to low doses of gamma irradiation. Also, inhibition of the two strains by probiotic strain Bacillus pumilus G4 was studied both in situ (in cheese) and in vitro (in culture media). The viable cell population of B. cereus GT1 increased from 106 to 2.9?×?108?CFU/g within 60?h in controls but decreased from 2.1?×?106 to 2.3?×?103?CFU/g after treatment with the probiotic strain. No viable count was observed after 60?h of incubation. Whereas, the viable cell population of S. aureus S1 increased from 106 to 2.5?×?108?CFU/g within 60?h in controls but decreased from 1.5?×?106 to 4.3?×?102?CFU/g after treatment with the probiotic strain. No viable count was observed after 54?h of incubation. 相似文献
122.
123.
Syazwan Afif Mohd Zobir Zulkarnain Zainal Mohd Zobir Hussein 《Materials Chemistry and Physics》2010,124(1):477-481
The effect of the addition of very small amount of polyvinyl alcohol (PVA) on the resulting physicochemical properties of ZnO synthesized by ethylene glycol-hydrothermal method was studied. Significant change in particle size distribution and specific surface area can be observed even only 0.02% PVA (w/w) was added into the ethylene glycol (EG) solution, in which the median particle size distribution increased from 5 to 8 nm and at the same time the specific surface area is also increased to nearly 50%. Further addition of PVA resulted in the decrease of the specific surface area due to the formation of agglomeration and aggregation of particles as observed by FESEM study. This study shows that the presence of minute amount of polymer, PVA plays very crucial role in determining the resulting properties of the synthesized ZnO by EG-hydrothermal method. 相似文献
124.
125.
A. Aguilar-Arevalo M. Blecher D.A. Bryman J. Comfort J. Doornbos L. Doria A. Hussein N. Ito S. Kettell L. Kurchaninov C. Malbrunot G.M. Marshall T. Numao R. Poutissou A. Sher B. Walker K. Yamada 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2009,609(2-3):102-105
An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay π+→e+ν is also described. 相似文献
126.
Christophe Rapine Nadia Brauner Gerd Finke Vassilissa Lebacque 《Journal of Scheduling》2012,15(2):127-139
For an industrial application in the chemical industry, we were confronted with the planning of experiments, where human intervention
of a chemist is required to handle the starting and termination of each of the experiments. This gives rise to a new type
of scheduling problem, namely problems of finding schedules with time periods when the tasks can neither start nor finish.
We consider in this paper the natural case of small periods where the duration of the periods is smaller than any processing time. This assumption corresponds to our chemical
experiments lasting several days, whereas the operator unavailability periods are typically single days or week-ends. These
problems are analyzed on a single machine with the makespan as criterion. 相似文献
127.
Elyas Sadeq Alaghbari Zulkarnain Zainal Imad Hamadneh Mohd Zobir Bin Hussein Mohd Haniff Bin Wahid 《Journal of Superconductivity and Novel Magnetism》2012,25(2):255-260
Zn- and Ca-doped ErBa2Cu3O7−δ
were successfully prepared via coprecipitation method using metal acetates as the starting salts. The precipitated samples
were calcined for 20 h at 900 °C and sintered at 920 °C for 24 h. All heat treatments were carried out under oxygen environment.
Results show that there is a selectivity of the doping site depending on the ionic radius of the dopant. Furthermore, increase
in the critical temperature, T
c
, was observed in 0.05 mole of calcium and zinc doped samples. The difference in ionic radius of the dopant led to the increase
in porosity as the ionic radius decreases. On the other hand, structural distortion increased as the difference of ionic radius
became larger. 相似文献
128.
Aline T. PERES Maria A. DALBONI Maria E. CANZIANI Silvia R. MANFREDI Jose Tarcisio G. CARVALHO Marcelo C. BATISTA Lilian CUPPARI Aluisio B. CARVALHO Rosa M. A. MOYSES Nadia GUIMARÃES Vanda JORGETTI Maria C. ANDREOLI Sergio A. DRAIBE Miguel CENDOROGLO 《Hemodialysis international. International Symposium on Home Hemodialysis》2009,13(3):271-277
It has been suggested that phosphate binders may reduce the inflammatory state of hemodialysis (HD) patients. However, it is not clear whether it has any effect on oxidative stress. The objective of this study was to evaluate the effect of sevelamer hydrochloride (SH) and calcium acetate (CA) on oxidative stress and inflammation markers in HD patients. Hemodialysis patients were randomly assigned to therapy with SH (n=17) or CA (n=14) for 1 year. Before the initiation of therapy (baseline) and at 12 months, we measured in vitro reactive oxygen species (ROS) production by stimulated and unstimulated polymorphonuclear neutrophils and serum levels of tumor necrosis factor α, interleukin-10, C-reactive protein, and albumin. There was a significant reduction of spontaneous ROS production in both groups after 12 months of therapy. There was a significant decrease of Staphylococcus aureus stimulated ROS production in the SH group. There was a significant increase in albumin serum levels only in the SH group. In the SH group, there was also a decrease in the serum levels of tumor necrosis factor α and C-reactive protein. Our results suggest that compared with CA treatment, SH may lead to a reduction in oxidative stress and inflammation. Therefore, it is possible that phosphate binders exert pleiotropic effects on oxidative stress and inflammation, which could contribute toward decreasing endothelial injury in patients in HD. 相似文献
129.
With increases in storm frequency and intensity, municipalities are finding new ways of managing stormwater. Solutions require collaboration across planning disciplines and input from an informed public. This study compares a system of bioswales to existing curb and gutter infrastructure in a post-industrial streetscape of Hamilton, Ontario. Using the geodesign process, a section of Ottawa St. North was modelled to show how green infrastructure can ease the burden on aging, combined sewer systems. Qualitative data was gathered from residents of the neighbourhood through field notes, and quantitative geospatial data through GIS. Parametric modelling was used to generate a design, and scenarios created to show resulting impacts on stormwater run-off. The model was posted online as an interactive presentation, accessible to all stakeholders for review and comment. The results of the study demonstrate powerful new tools that can assist landscape architects in designing, collaborating and communicating stormwater strategies. 相似文献
130.