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51.
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CJ Frary RB Devereux R Kramer-Fox RB Roberts HS Ruchlin 《Canadian Metallurgical Quarterly》1994,73(4):263-267
In 1990-1991, a national survey was conducted to estimate the prevalence of Salmonella species among Canadian commercial turkey flocks. Two hundred and seventy flocks were randomly selected across Canada. The proportion sampled from each province was selected according to each province's share of the national turkey market. Samples, consisting of 12 pooled litter and four pooled dust samples, were used to determine the Salmonella status of the environment of each flock. Additionally, a one kilogram sample of feed was taken from each flock premise. Salmonella was recovered from environmental samples in 234/270 (86.7%) of flocks and from feed samples in 26/266 (9.8%) of flocks. Forty-eight different Salmonella serovars were isolated from flock environmental samples. The most prevalent serovars were S. anatum, S. hadar, S. agona, S. heidelberg and S. saintpaul which were isolated from 53/270 (19.6%), 49/270 (18.1%), 49/270 (18.1%), 42/270 (15.6%) and 34/270 (12.6%) flocks, respectively. 相似文献
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The present study characterised seven species of the Chabertiidae (Nematoda: Strongyloidea) belonging to either the subfamily Oesophagostominae (Oesophagostomum radiatum, Oesophagostomum venulosum, Oesophagostomum dentatum, Oesophagostomum quadrispinulatum, Oesophagostomum columbianum, Oesophagostomum bifurcum) or to the subfamily Chabertiinae (Chabertia ovina) by their second internal transcribed spacer rDNA sequence, assessed the extent of intraspecific variation and interspecific differences in the sequence, and inferred the phylogenetic relationship of C. ovina with respect to members of the Oesophagostominae. In both the phenetic and cladistic analyses of the sequence data, Chabertia was nested within Oesophagostomum, suggesting either that the species examined represent members of the same genus, or alternatively, that Oesophagostomum may represent more than one genus. 相似文献
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Robert A. Moreau David B. Johnston Kevin B. Hicks 《Journal of the American Oil Chemists' Society》2007,84(11):1039-1044
All commercial corn oil is obtained by pressing corn germ and/or extracting the germ with hexane. In the current study, six
types of corn oil were prepared by extracting corn germ, corn fiber and ground corn, each with hexane or with ethanol. The
levels of lutein, zeaxanthin and other carotenoids were quantitatively analyzed in the six corn oils. The levels of lutein + zeaxanthin
in the oil ranged from 2.3 μg/g for hexane-extracted corn germ oil to 220.9 μg/g for ethanol-extracted ground corn oil. These
results indicate that a diet that includes 30 g (~2 tbsp) per day of the unrefined corn oil obtained by extracting ground
corn with ethanol would provide ~6 mg of lutein + zeaxanthin, the daily dosage that is currently considered to be necessary
to slow the progression of age-related macular degeneration.
Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information
and does not imply recommendation or endorsement by the U.S. Department of Agriculture. 相似文献
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Reactive Laser Ablation Synthesis of Nanosize Alumina Powder 总被引:1,自引:0,他引:1
Gregory P. Johnston Ross Muenchausen Douglas M. Smith William Fahrenholtz Steve Foltyn 《Journal of the American Ceramic Society》1992,75(12):3293-3298
An aluminum (Al) target was laser ablated in an oxygen (O2 ) atmosphere, producing nanosize alumina (Al2 O3 ) powder. The powder surface area decreased (and the particle size increased) with both increasing oxygen pressure and laser fluence. All powders produced had surface areas between 135 and 250 m2 /g, corresponding to primary particle sizes ranging from 7 to 3 nm in radius. Phase evolution with temperature was studied via X-ray diffraction. These powders showed a direct transformation from γ- to α-alumina at approximately 1200°C, bypassing other transition alumina phases, while still maintaining small particle size ( 30 nm). Despite the nanosize particles, green densities equal to 54% of the skeletal density (i.e., true density of the solid phase) were obtained by uniaxial pressing at 40 MPa. 相似文献
59.
Gregory P. Johnston Ross E. Muenchausen Douglas M. Smith Steve R. Foltyn 《Journal of the American Ceramic Society》1992,75(12):3465-3468
An aluminum (Al) target was laser ablated in a nitrogen (N2 ) atmosphere, producing aluminum nitride (AlN) powder. These powders were calcined at 900°C for 2 h. Powders were produced at various nitrogen pressures, and the calcined powders were tested for unreacted aluminum content, using differential thermal analysis (DTA). The AlN powder, produced at a laser fluence of 12 J/cm2 and a nitrogen pressure of 10.0 kPa (75 torr), showed no evidence of unreacted aluminum by DTA and was phase-pure AlN by X-ray diffraction (XRD). The surface area of this powder is 82 m2 /g, corresponding to a particle size of ∼11 nm, which is in good agreement with TEM observations. 相似文献
60.
J. H. Bordon J. R. Handley J. A. McLean R. M. Silverstein L. Chong K. N. Slessor B. D. Johnston H. R. Schuler 《Journal of chemical ecology》1980,6(2):445-456
The aggregation pheromone ofGnathotrichus retusus was isolated and identified as (S)-(+)-sulcatol (6-methyl-5-hepten-2-ol). In laboratory and field experiments,G. retusus responded to (S)-(+)-sulcatol, but not to (±)-sulcatol, which was attractive to the sympatric species,G. sulcatus. G. sulcatus did not respond to optically pure (S)-(+)-sulcatol, but began to respond when 1% (R)-(–)-sulcatol was present in an enantiomeric mixture.Research supported by the National Science Foundation, U.S.A. (Grant BMS-74-13643), and the Natural Sciences and Engineering Research Council of Canada (Co-op grant A0243 and Operating Grant A3881 and A3785). 相似文献