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排序方式: 共有461条查询结果,搜索用时 15 毫秒
61.
Effect of dietary supplementation of different oils during the first or second half of pregnancy on the glucose tolerance of the sow 总被引:1,自引:0,他引:1
Corson AM Laws J Litten JC Dodds PF Lean IJ Clarke L 《Animal : an international journal of animal bioscience》2008,2(7):1045-1054
Poor glucose tolerance may be an under-researched contributory factor in the high (10% to 20%) pre-weaning mortality rate observed in pigs. Insulin resistance commences at around week 12 of gestation in the sow, although there are conflicting reports in the literature about the extent to which insulin resistance is modulated by maternal diet. The aim of the study was to determine the effects of supplementing the maternal diet with different dietary oils during either the first half or the second half of gestation on the glucose tolerance of the sow. Sows were offered the control (C: n = 5) diet as pellets or the C diet plus 10% extra energy (n = 16 per group) derived from either: (i) extra pellets; (ii) palm oil; (iii) olive oil; (iv) sunflower oil; or (v) fish oil. Experimental diets were fed during either the first (G1) or second (G2) half of gestation. A glucose tolerance test (GTT) was conducted on day 108 of gestation by administering 0.5 g/kg glucose i.v. Blood samples were taken every 5 to 10 min for 90 min post administration. The change in body weight and backfat thickness during gestation was similar but both type and timing of dietary supplementation influenced litter size and weight. With the exception of the sunflower oil group, supplementing the maternal diet in G1 resulted in larger and heavier litters, particularly in mothers offered palm oil. Basal blood glucose concentrations tended to be more elevated in G1 than G2 groups, whilst plasma insulin concentrations were similar. Following a GTT, the adjusted area under the curve was greater in G1 compared to G2 sows, despite no differences in glucose clearance. Maternal diet appeared to influence the relationship between glucose curve characteristics following a GTT and litter outcome. In conclusion, the degree of insulin sensitivity can be altered by both the period during which maternal nutritional supplementation is offered and the fatty acid profile of the diet. 相似文献
62.
Randall J. Bernot Walter K. Dodds Michael C. Quist Christopher S. Guy 《Hydrobiologia》2004,525(1-3):101-112
Seasonal and daily patterns of zooplankton populations are often predictable in natural lakes. Distinct zonation and geomorphic differences in reservoirs, however, make ecological extrapolations from lakes to reservoirs uncertain. We describe the spatial and temporal distribution of zooplankton, algae, and water clarity across reservoir zones and along a depth gradient in Glen Elder Reservoir, Kansas. Daphnia species were most abundant in the lacustrine zone, with D. pulicaria numerically dominant in early spring and D. mendotae dominant later in 1999 and 2000. Rotifers (Keratella quadrata, Asplanchnaspp.) were dominant in the riverine zone in 1999, 2000, and 2001. Algal biomass was not significantly different between zones through most of the sampling periods, except late April in 1999 and mid-April in 2000. Chlorophyll a exceeded 81 μg l?1 in the lacustrine zone in mid- to late-April in 1999 and 2000, and exceeded 90μg l?1in the riverine zone in mid-April. Water clarity was significantly lower in the riverine zone in 1999 and 2000. Most zooplankton taxa had similar depth distributions at night and day, indicating a lack of diel vertical migration behavior on a large scale. However, in small scale (30 cm vertical enclosures) laboratory experiments, both D. pulicaria and D. mendotae occupied significantly deeper depths (>25 cm) under lighted conditions in the presence of fish chemical cues compared to shallow water (7–17 cm) under dark conditions and in the absence of fish cues. These contrasting results suggest that, as in other studies, Daphnia sense cues from predators and alter their depth in the water column on small scales without natural constraints on movement and choices. However, other factors in the reservoir such as wind-generated water movements and cues from other predators may prevent depth choices similar to those seen under controlled conditions. These results illustrate biotic and abiotic differences between riverine and lacustrine zones in a large reservoir, and contrast with Daphnia depth segregation and migration patterns in natural lakes. 相似文献
63.
In view of the fact that memory effects associated with instrument calibration hinder the use of many mass-to-charge (m/z) ratios and tuning standards, identification of robust, comprehensive, inexpensive, and memory-free calibration standards is of particular interest to the mass spectrometry community. Glucose and its isomers are known to have a residue mass of 162.05282 Da; therefore, both linear and branched forms of polyhexose oligosaccharides possess well-defined masses, making them ideal candidates for mass calibration. Using a wide range of maltooligosaccharides (MOSs) derived from commercially available beers, ions with m/z ratios from approximately 500 to 2500 Da or more have been observed using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and time-of-flight mass spectrometry (TOF-MS). The MOS mixtures were further characterized using infrared multiphoton dissociation (IRMPD) and nano-liquid chromatography/mass spectrometry (nano-LC/MS). In addition to providing well-defined series of positive and negative calibrant ions using either electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI), the MOSs are not encumbered by memory effects and, thus, are well-suited mass calibration and instrument tuning standards for carbohydrate analysis. 相似文献
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65.
Combined effect of water activity and pH on inhibition of toxin production by Clostridium botulinum in cooked, vacuum-packed potatoes 总被引:2,自引:0,他引:2
K L Dodds 《Applied and environmental microbiology》1989,55(3):656-660
The effects of water activity (aw, 0.955 to 0.970), pH (4.75 to 5.75), and storage time (up to 60 days) on toxin production by Clostridium botulinum in cooked, vacuum-packed potatoes were studied by using factorial design experiments and most-probable-number methodology. Samples were inoculated with 10(3), 10(4), or 10(5) spores of a mixture of five type A and five proteolytic type B strains, incubated at 25 degrees C, and analyzed for toxin production. Toxin was produced at pH levels of greater than or equal to 4.75 when the aw was greater than or equal to 0.970, pH greater than 5.25 when the aw was 0.965, and pH greater than or equal to 5.75 at an aw of 0.960. No toxin was detected when the aw was 0.955. The probability of toxigenesis was significantly affected (P less than 0.0001) by storage time, aw, pH, and the interactions aw.pH and aw.storage time. The response to a decrease in pH was linear, while the response to a decrease in aw was curvilinear. Using multiple linear regression, equations were derived which could predict the length of time until toxin production and the probability of toxigenesis by a single spore under defined conditions. 相似文献
66.
Shuai Shi Elizabeth S. Dodds Ashley Barbara D. Alexander Anthony J. Hickey 《AAPS PharmSciTech》2009,10(1):129-137
Pharmaceutical aerosols have been targeted to the lungs for the treatment of asthma and pulmonary infectious diseases successfully.
Micafungin (Astellas Pharma US, Deerfield, IL, USA) has been shown to be an effective antifungal agent when administrated
intravenously. Pulmonary delivery of micafungin has not previously been reported. In the present pilot study, we characterize
the performance of two nebulizers and their potential for delivering micafungin to the lungs as well as the use of multivariate
data analysis for mass distribution profile comparison. The concentration of micafungin sodium increased by 21% when delivered
by the Acorn II nebulizer and by 20% when delivered by the LC Plus nebulizer, respectively, from the first to the second sampling
period. The Acorn II nebulizer delivered a fine particle fraction FPF5.8 (%<5.8 μm) of 92.5 ± 0.8 and FPF3.3 (%<3.3 μm) of 82.3 ± 2.1 during the first sampling period. For the LC Plus nebulizer, FPF5.8 was 92.3 ± 0.1 and FPF3.3 was 67.0 ± 0.7 during the first sampling period. The mass median aerodynamic diameter (MMAD) increased from 1.67 ± 0.05 to
1.77 ± 0.04 μm (Acorn II nebulizer) and from 2.09 ± 0.01 to 2.20 ± 0.01 μm (Pari LC Plus nebulizer) from the first to the
second sampling periods. These changes in MMAD were statistically significant by paired t test. Multivariate data analysis showed that this could be explained systematically by greater drug deposition on stages
with larger cutoff sizes and reduced drug deposition on stages with smaller cutoff sizes rather than multimodal deposition
or other anomalies in size distribution. 相似文献
67.
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69.
Francesco D'Amato G. P. Frets O. H. Pearson Richard Hopp G. W Bonn Charles M. Rick Jeanette Robinson Darrell G. Wells G. K. Bondarenko B. I. Chmelev O. Heinisch Earlene Atchison A. J. Bateman K. Mather Werner Gottschalk Donald H. Scott Deane C. Arny K. S. Dodds F. W. Cope Franz Frimmel N. Hess G. Mrkos F. Graf Mengersen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1953,23(6):190-192
Ohne Zusammenfassung 相似文献
70.